Photoreactor composition method of generating a reactive species and applications therefor

Information

  • Patent Grant
  • 6071979
  • Patent Number
    6,071,979
  • Date Filed
    Friday, December 26, 1997
    26 years ago
  • Date Issued
    Tuesday, June 6, 2000
    24 years ago
Abstract
A method of generating reactive species which includes exposing a wavelength specific photoreactor to radiation, in which the wavelength specific photoreactor comprises a wavelength-specific sensitizer associated with one or more reactive species-generating photoinitiators. Also described are methods of polymerizing unsaturated monomers and curing an unsaturated oligomer/monomer mixture.
Description

TECHNICAL FIELD
The present invention relates to a composition and method for generating a reactive species. The present invention more particularly relates to a composition and method for generating reactive species which can be used to polymerize or photocure polymerizable unsaturated material. In particular, the present invention provides a photoreactor that absorbs radiation at a wavelength that is particularly suited to exposure to lamps that emit at substantially the same wavelength.
BACKGROUND OF THE INVENTION
The present invention relates to a method of generating a reactive species. The present invention also relates to radiation-initiated polymerization and curing processes. For convenience, much of the discussion which follows centers on free radicals as a particularly desirable reactive species. Such discussion, however, is not to be construed as limiting either the spirit or scope of the present invention.
Polymers have served essential needs in society. For many years, these needs were filled by natural polymers. More recently, synthetic polymers have played an increasingly greater role, particularly since the beginning of the 20th century. Especially useful polymers are those prepared by an addition polymerization mechanism, i.e., free radical chain polymerization of unsaturated monomers, and include, by way of example only, coatings and adhesives. In fact, the majority of commercially significant processes is based on free-radical chemistry. That is, chain polymerization is initiated by a reactive species which often is a free radical. The source of the free radicals is termed an initiator or photoinitiator.
Improvements in free radical chain polymerization have focused both on the polymer being produced and the photoinitiator. Whether a particular unsaturated monomer can be converted to a polymer requires structural, thermodynamic, and kinetic feasibility. Even when all three exist, kinetic feasibility is achieved in many cases only with a specific type of photoinitiator. Moreover, the photoinitiator can have a significant effect on reaction rate which, in turn, may determine the commercial success or failure of a particular polymerization process or product.
A free radical-generating photoinitiator may generate free radicals in several different ways. For example, the thermal, homolytic dissociation of an initiator typically directly yields two free radicals per initiator molecule. A photoinitiator, i.e., an initiator which absorbs light energy, may produce free radicals by either of two pathways:
(1) the photoinitiator undergoes excitation by energy absorption with subsequent decomposition into one or more radicals: or
(2) the photoinitiator undergoes excitation and the excited species interacts with a second compound (by either energy transfer or a redox reaction) to form free radicals from the latter and/or former compound(s).
While any free radical chain polymerization process should avoid the presence of species which may prematurely terminate the polymerization reaction, prior photoinitiators present special problems. For example, absorption of the light by the reaction medium may limit the amount of energy available for absorption by the photoinitiator. Also, the often competitive and complex kinetics involved may have an adverse effect on the reaction rate. Moreover, commercially available radiation sources, such as medium and high pressure mercury and xenon lamps, emit over a wide wavelength range, thus producing individual emission bands of relatively low intensity. Most photoinitiators only absorb over a small portion of the emission spectra and, as a consequence, most of the lamps radiation remains unused. In addition, most known photoinitiators have only moderate quantum yields (generally less than 0.4) at these wavelengths, indicating that the conversion of light radiation to radical formation can be more efficient.
Thus, there are continuing opportunities for improvements in free radical polymerization photoinitiators.
SUMMARY OF THE INVENTION
The present invention addresses some of the difficulties and problems discussed above by the discovery of an efficient composition and method for utilizing radiation. Hence, the present invention includes a compositions and methods for generating a reactive species which includes providing one or more wavelength-specific sensitizers in association with one or more reactive species-generating photoinitiators and irradiating the resulting wavelength specific photoreactor composition. One of the main advantages of the wavelength specific photoreactor composition of the present invention is that it can be used to efficiently generate reactive species under extremely low energy lamps as compared to prior art lamps.
The association of one or more wavelength-specific sensitizers with one or more reactive species-generating photoinitiators results in a structure referred to herein for convenience as a wavelength specific photoreactor composition. The present invention includes arylketoalkene wavelength-specific sensitizers. One major advantage of the wavelength specific photoreactor compositions is the use of arylketoalkene wavelength-specific sensitizers. The wavelength specific photoreactor compositions that contain the arylketoalkene wavelength-specific sensitizers efficiently absorb radiation at wavelengths between approximately 250 nm and 350 nm. Another major advantage of the wavelength specific photoreactor compositions of the present invention is that, when combined with polvmerizable material, they cause rapid curing times in comparison to the curing times of the prior art with relatively low output lamps. Yet another advantage of the of the present invention is that the multi-photoinitiator photoreactors of the present invention or the multi-wavelength specific sensitizer photoreactors have even faster curing times in comparison to the single-photoinitiator photoreactors of the present invention and/or are more sensitive than the single sensitizer photoreactors of the present invention.
The wavelength specific photoreactor compositions of the present invention also differ from the prior art in that the prior art sensitizers absorb a band width of radiation, whereas the sensitizer of the present invention absorbs a substantially single wavelength. The use of a wavelength specific photoreactor composition capable of absorbing a substantially single wavelength of radiation results in an extremely efficient photoreactor upon exposure to a very narrow bandwidth of radiation or upon exposure to a single wavelength of radiation.
The present method involves effectively tuning the energy-absorbing entity, referred to herein as a wavelength specific photoreactor composition, to efficiently utilize an emitted band of radiation. The wavelength-specific sensitizer effectively absorbs photons and efficiently transfers the absorbed energy to a photoinitiator which, in turn, generates a reactive species. The wavelength-specific sensitizer is adapted to have an absorption peak generally corresponding to a maximum emission band of the radiation source.
The present invention includes various combinations of wavelength-specific sensitizers and photoinitiators. By varying the combination, one can effectively increase the number of photoinitiators per wavelength specific photoreactor composition or effectively increase the number of wavelength-specific sensitizers per photoreactive composition.
The present invention also includes a method of polymerizing an unsaturated monomer by exposing the unsaturated monomer to radiation in the presence of the efficacious wavelength specific photoreactor composition described above. When an unsaturated oligomer/monomer mixture is employed in place of the unsaturated monomer, curing is accomplished.
The present invention further includes a film and a method for producing a film, by drawing an admixture of unsaturated polymerizable material and the wavelength specific photoreactor composition of the present invention, into a film and irradiating the film with an amount of radiation sufficient to polymerize the composition. When the unsaturated polymerizable material is an unsaturated oligomer/monomer mixture, curing is accomplished. The admixture may be drawn into a film on a nonwoven web or on a fiber, thereby providing a polymer-coated nonwoven web or fiber, and a method for producing the same.
The film can be a film containing a dye or a pigment and can be used in the printing industry. The film with the dye or pigment therein is applied to a substrate such as paper and is then exposed to a source of electromagnetic radiation at the appropriate wavelength thereby causing the film to be cured. The use of the present invention in the printing industry has several advantages including increased printing speeds, lower energy consumption, and lower heat production.
The present invention also includes an adhesive composition comprising an unsaturated polymerizable material admixed with the wavelength specific photoreactor composition of the present invention. Similarly, the present invention includes a laminated structure comprising at least two layers bonded together with the above described adhesive composition, in which at least one layer is a cellulosic or polyolefin nonwoven web or film. Accordingly, the present invention provides a method of laminating a structure wherein a structure having at least two layers with the above described adhesive composition between the layers is irradiated to polymerize the adhesive composition. When the unsaturated polymerizable material in the adhesive is an unsaturated oligomer/monomer mixture, the adhesive is irradiated to cure the composition.





BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of the excimer lamp employed in some of the examples.





DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to the unexpected discovery of an efficient reactive species-generating composition and methods for utilizing the same. More particularly, the present invention includes a composition and method for generating a reactive species which includes providing one or more wavelength-specific sensitizers in association with one or more reactive species-generating photoinitiators and irradiating the wavelength-specific sensitizer. The association of one or snore wavelength-specific sensitizers with one or more reactive species-generating photoinitiators results in a structure referred to herein for convenience as a wavelength specific photoreactor composition.
The present invention also includes a method of polymerizing an unsaturated polymerizable material by exposing the unsaturated material to radiation in the presence of the efficacious wavelength specific photoreactor composition described above. Further, the present invention includes a film and a method for producing a film, by drawing an admixture of unsaturated polymerizable material and the wavelength specific photoreactor composition of the present invention, into a film and irradiating the film with an amount of radiation sufficient to polymerize the composition.
The film can be a film containing a dye or a pigment and can be used in the printing industry. The film with the dye or pigment therein is applied to a substrate such as paper and is then exposed to a source of electromagnetic radiation at the appropriate wavelength thereby causing the film to be cured. The use of the present invention in the printing industry has several advantages including increased printing speeds, lower energy consumption, and lower heat production.
Also, the present invention includes an adhesive composition comprising an unsaturated polymerizable material admixed with the wavelength specific photoreactor composition of the present invention. Similarly, the present invention includes a laminated structure comprising at least two layers bonded together with the above described adhesive composition, in which at least one layer is a cellulosic or polyolefin nonwoven web or film. Accordingly, the present invention provides a method of laminating a structure wherein a structure having at least two layers with the above described adhesive composition between the layers is irradiated to polymerize the adhesive composition.
The wavelength specific photoreactor composition of the present invention will be described in detail below, followed by a detailed description of the method of generating reactive species, and the various representative applications of the method.
The wavelength specific photoreactor composition of the present invention is one or more wavelength-specific sensitizers associated with one or more reactive species-generating photoinitiators. Accordingly, the term "wavelength specific photoreactor composition" is used herein to mean one or more wavelength-specific sensitizers associated with one or more reactive species-generating photoinitiators. In an embodiment where the sensitizer(s) is admixed with the photoinitiator(s), the term "wavelength specific photoreactor composition" is used to mean the admixture. In the embodiment where the sensitizer(s) are covalently bonded to the photoinitiator(s), the term "wavelength specific photoreactor composition" is used to mean the resultant molecule. The term "single-photoinitiator photoreactor" is used to mean a wavelength specific photoreactor composition having one reactive species-generating photoinitiator therein. The term "multi-photoinitiator photoreactor" is used to mean a wavelength specific photoreactor composition having more than one reactive species-generating photoinitiator. Therefore, it follows that the term "double-photoinitiator photoreactor" is used to mean a wavelength specific photoreactor composition having two reactive species-generating photoinitiators. The present invention also contemplates a wavelength specific photoreactor wherein there is a single reactive species-generating photoinitiator and multiple wavelength-specific sensitizers. Accordingly, the term "double-sensitizer photoreactor" is used to mean a wavelength specific photoreactor composition having two wavelength-specific sensitizers. Finally, the present invention includes wavelength specific photoreactor compositions with multiple wavelength specific sensitizers and multiple reactive species-generating photoinitiators.
The term "associated" as used herein is meant to include any means which results in the wavelength-specific sensitizer(s) and the reactive species-generating photoinitiator(s) being in sufficiently close proximity to each other to permit the transfer of energy absorbed by the sensitizer(s) to the photoinitiator(s). For example, the wavelength-specific sensitizer(s) and the reactive species-generating photoinitiator(s) may be bonded to each other or to a spacer molecular as described hereinafter by covalent, hydrogen, van der Waals, or ionic bonds. Alternatively, the sensitizer(s) and the photoinitiator(s) may be physically admixed.
The term "wavelength-specific sensitizer" is used herein to mean that the sensitizer is adapted to have an absorption wavelength band generally corresponding to an emission peak of the radiation. Either or both of the sensitizer and the radiation may have more than one absorption wavelength band and emission peak, respectively. In the event both the sensitizer and the radiation have more than one absorption wavelength band and emission peak, respectively, the general correspondence just described need not be limited to a single absorption wavelength band and a single emission peak.
According to the present invention, a desirable "wavelength-specific sensitizer" is an arylketoalkene wavelength-specific sensitizer having the following general formula: ##STR1## wherein R.sub.1 is hydrogen, an alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;
R.sub.2 is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group;
R.sub.3 is hydrogen, alkyl, alkenyl, cycloalkyl, heterocycloalkyl, aryl or a heteroaryl group; and
R.sub.4 is an aryl, heteroaryl, or substituted aryl group.
Desirable sensitizer produced by the process of dehydrating a tertiary alcohol that is alpha to a carbonyl group on a sensitizer is represented in the following general formula: ##STR2## wherein when R.sub.1 is an aryl group, R.sub.2 is a hydrogen; alkyl; aryl; heterocyclic; or phenyl group, the phenyl group optionally being substituted with an alkyl, halo, amino, or thiol group; and wherein when R.sub.2 is an aryl group, R.sub.1 is a hydrogen; alkyl; aryl; heterocyclic; or phenyl group, the phenyl group optionally being substituted with an alkyl, halo, amino, or thiol group. Preferably, the alkene group is in the trans configuration. The wavelength-specific sensitizer of the present invention contains an aryl group, a carbonyl group, and a double bond (alkene group), in any order, such that resonance of the unshared electrons occurs.
Desirably, the arylketoalkene sensitizer is a chalcone having the following formula: ##STR3## which efficiently absorbs radiation having a wavelength at about 308 nanometers, or is benzylideneacetone (4-phenyl-3-buten-2-one) having the following formula: ##STR4## which efficiently absorbs radiation having a wavelength at about 280 nanometers. Desirably, the sensitizer of the present invention is in the trans configuration with respect to the double bond. However, the sensitizer may also be in the cis configuration across the double bond.
Although the above sensitizers are desirable, any sensitizer known in the art capable of absorbing photons having a substantially specific wavelength and transferring the absorbed energy to an associated reactive-species generating photoinitiator may be used in the present wavelength specific photoreactor compositions. As a practical matter, two classes of compounds are known to be useful as wavelength-specific sensitizers, namely, phthalic acid derivatives and phenyl-substituted aliphatic ketones. A particularly useful example of each class is phthaloylglycine and 4-(4-hydroxyphenyl)butan-2-one, respectively. Therefore, another desirable sensitizer is phthaloylglycine having the following formula: ##STR5##
As stated above, the wavelength-specific sensitizer of the present invention may optionally be covalently bonded to one or more reactive species-generating photoinitiators. In that embodiment, the aryl group of a wavelength-specific sensitizer of the present invention can contain a group including, but not limited to, a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group attached thereto to allow the arylketoalkene to be covalently bonded to the other molecule. Accordingly, a desired arylketoalkene reactive compound includes the following: ##STR6##
Although it is preferred that the group attached to the aryl group is para to the remainder of the reactive molecule, the group may also be ortho or meta to the remainder of the molecule. Note that the di-carboxylic acid substituted chalcone type compound shown above can be covalently bonded to two photoinitiators, one photoinitiator on each aryl group substituted with a carboxylic acid group, thereby producing a double-photoinitiator photoreactor.
In the embodiment where the sensitizer is phthaloylglycine, and two photoinitiators are covalently bonded thereto, the phenyl group will contain a group including, but limited to, a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group attached thereto to allow the phthaloylglycine to be covalently bonded to one photoinitiator. Of course, the carboxylic acid group in the phthaloylglycine provides the second location for covalently bonding to the second photoinitiator.
The term "reactive species" is used herein to mean any chemically reactive species including, but not limited to, free-radicals, cations, anions, nitrenes, and carbenes. Illustrated below are examples of several of such species. Examples of carbenes include, for example, methylene or carbene, dichlorocarbene, diphenylcarbene, alkylcarbonylcarbenes, siloxycarbenes, and dicarbenes. Examples of nitrenes include, also by way of example, nitrene, alkyl nitrenes, and aryl nitrenes. Cations (sometimes referred to as carbocations or carbonium ions) include, by way of illustration, primary, secondary, and tertiary alkyl carbocations, such as methyl cation, ethyl cation, propyl cation, t-butyl cation, t-pentyl cation, t-hexyl cation; allylic cations; benzylic cations; aryl cations, such as triphenyl cation; cyclopropylmethyl cations; methoxymethyl cation; triarylsulphonium cations; and acyl cations. Cations also include those formed from various metal salts, such as tetra-n-butylammonium tetrahaloaurate(III) salts; sodium tetrachloroaurate(III); vanadium tetrachloride; and silver, copper(I) and (II), and thallium(I) triflates. Examples of anions (sometimes referred to as carbanions) include, by way of example, alkyl anions, such as ethyl anion, npropyl anion, isobutyl anion, and neopentyl anion; cycloalkyl anions, such as cyclopropyl anion, cyclobutyl anion, and cyclopentyl anion; allylic anions; benzylic anions; aryl cations; and sulfur- or phosphorus-containing alkyl anions. Finally, examples of organometallic photoinitiators include titanocenes, fluorinated diaryltitanocenes, iron arene complexes, manganese decacarbonyl, and methylcyclopentadienyl manganese tricarbony. Organometallic photoinitiators generally produce free radicals or cations.
Any reactive species-generating photoinitiator may be used which generates the desired reactive species. With regard to the free radical-generating photoinitiators, these photoinitiators may be any of the photoinitiators known to those having ordinary skill in the art. The largest group of photoinitiators are carbonyl compounds, such as ketones, especially .alpha.-aromatic ketones. Examples of .alpha.-aromatic ketone photoinitiators include, by way of illustration only, benzophenones; xanthones and thioxanthones; .alpha.-ketocoumarins; benzils; .alpha.-alkoxydeoxybenzoins; benzil ketals or .alpha.,.alpha.-dialkoxydeoxybenzoins; enzoyldialkylphosphonates; acetophenones, such as .alpha.-hydroxycyclohexyl phenyl ketone, .alpha.,.alpha.-dimethyl-.alpha.-hydroxyacetophenone, .alpha.,.alpha.-dimethyl-.alpha.-morpholino-4-methylthio-acetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylaminoacetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylamino-4-morpholinoacetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylamino-3,4-dimethoxyacetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylamino-4-methoxyacetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylamino-4-dimethylaminoacetophenone, .alpha.-ethyl-.alpha.-benzyl-.alpha.-dimethylamino-4-methylacetophenone, .alpha.-ethyl-.alpha.-(2-propenyl)-.alpha.-dimethylamino-4-morpholinoacetophenone, .alpha.,.alpha.-bis(2-propenyl)-.alpha.-dimethylamino-4-morpholinoacetophenone, .alpha.-methyl-.alpha.-benzyl-.alpha.-dimethylamino-4-morpholinoacetophenone, and .alpha.-methyl-.alpha.-(2-propenyl)-.alpha.-dimethylamino-4-morpholinoaceto-phenone; .alpha.,.alpha.-dialkoxyaceto-phenones; .alpha.-hydroxyalkylphenones; O-acyl .alpha.-oximino ketones; acylphosphine oxides; fluorenones, such as fluorenone, 2-t-butylperoxycarbonyl-9-fluorenone, 4-t-butylperoxyvarbonyl-nitro-9-fluorenone, and 2,7-di-t-butylperoxy-carbonyl-9-fluorenone; and .alpha.- and .beta.-naphthyl carbonyl compounds. Other free radical generating photoinitiators include, by way of illustration, triarylsilyl peroxides, such as triarylsilyl t-butyl peroxides; acylsilanes; and some organometallic compounds. The free radical-generating initiator desirably will be an acetophenone. More desirably, the photoinitiator will be IRGACURE.RTM.-2959 (1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one or 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone).
The types of reactions that various reactive species enter into include, but are not limited to, addition reactions, including polymerization reactions; abstraction reactions; rearrangement reactions: elimination reactions, including decarboxylation reactions; oxidation-reduction (redox) reactions; substitution reactions; and conjugation/deconjugation reactions.
In the embodiments where one or more wavelength-specific sensitizers are bound to one or more reactive species-generating photoinitiators, any suitable method that is known in the art may be used to bond the sensitizer(s) to the photoinitiator(s). The choice of such method will depend on the functional groups present in the sensitizers and photoinitiators and is readily made by those having ordinary skill in the art. Such bonding may be accomplished by means of functional groups already present in the molecules to be bonded, by converting one or more functional groups to other functional groups, by attaching functional groups to the molecules, or through one or more spacer molecules.
Examples 1-3 herein describe methods of preparing the arylketoalkene sensitizer of the present invention, and covalently bonding it to a photoinitiator, namely IRGACURE.RTM.-2959. The reaction described in Example 3 may be used on any arylketoalkene sensitizer of the present invention having a carboxylic acid functional group on R.sub.1 or R.sub.2 whichever is the aryl group. This reaction of any arylketoalkene sensitizer is represented by the formula below, wherein R.sub.3 represents the remainder of the arylketoalkene sensitizer of the present invention, and wherein the carboxylic acid group is attached to R.sub.1 and/or R.sub.2 : ##STR7##
In the embodiment where both R.sub.1 and R.sub.2 are phenyl groups, if a carboxylic acid group is attached to only one of the phenyl groups, a single-photoinitiator photoreactor is produced. In the embodiment where both R.sub.1 and R.sub.2 are phenyl groups, and a carboxylic acid group is attached to both phenyl groups, a double-photoinitiator photoreactor is produced.
Desirably, the wavelength specific photoreactor composition of the present invention is represented by the to following formula: ##STR8##
More desirably, the wavelength specific photoreactor composition of the present invention is represented by the following formulas: ##STR9##
Another wavelength specific photoreactor composition that is considered part of the present invention is the compound represented by the following formula: ##STR10##
Synthesis of this wavelength specific photoinitiator composition is described in Examples 9 through 12 herein.
Another wavelength specific photoreactor composition of the present invention is a "double-photoinitiator photoreactor" or a "double-sensitizer photoreactor". These compositions, for example the double-photoinitiator or the double-sensitizer photoreactor compositions, are generally more sensitive to the electromagnetic radiation and are useful in situations were increased sensitivity is required. Although not wanting to be limited by the following, it is theorized that the double-photoinitiator photoreactor is more sensitive as more reactive species are generated per photon absorbed than if the photoreactor contained only one reactive-species generating photoinitiator. Also, although not wanting to be limited by the following, it is theorized that the double-sensitizer photoreactor is more likely to absorb a photon of radiation than a single-sensitizer photoreactor as the double-sensitizer photoreactor contains two sensitizers, and therefore in situations where there is little light present, such a double-sensitizer photoreactor is more likely to absorb radiation than a photoreactor having only one sensitizer.
One example of a double-photoinitiator wavelength specific photoreactor composition of the present invention is represented by the following formula: ##STR11##
Example 6 herein describes a method of preparing a double carboxylic acid substituted chalcone and then the method of preparing the above double-photoinitiator photoreactor. The reaction for preparing the double-photoinitiator photoreactor described in Example 6 may be used on any sensitizer of the present invention having two carboxylic acid functional groups on each end of the sensitizer.
The method of preparing the double carboxylic acid substituted chalcone is illustrated as follows: ##STR12##
It is to be understood that any methods known to those of ordinary skill in the chemical arts may be used to prepare the above double carboxylic acid substituted chalcone, or any other double carboxylic acid substituted sensitizer. It is also to be understood that any methods known in the art may be used to prepare sensitizers that are substituted with one or more of the other functional groups listed above. It is further to be understood that the functional groups on a sensitizer may be the same or they may be different.
The method of preparing the double-photoinitiator photoreactor from the above double carboxylic acid substituted chalcone is illustrated as follows: ##STR13##
It is to be understood that the above illustrated double-photoinitiator photoreactor is specifically referred to as the "chalcone double-photoinitiator photoreactor", in contrast to other double-photoinitiators within the present invention as will be further discussed below.
As discussed above, sensitizers other than the arylketoalkene sensitizers above may be in the wavelength specific photoreactor compositions of the present invention. For example, the sensitizer phthaloylglycine may be covalently bonded to one or two photoinitiators as is illustrated below, wherein the top wavelength specific photoreactor composition is one IRGACURE.RTM.-2959 photoinitiator covalently bonded to phthaloylglycine and the bottom wavelength specific photoreactor composition is two IRGACURE.RTM.-2959 photoinitiators covalently bonded to phthaloylclycine. ##STR14##
Another wavelength specific photoreactor composition of the present intention is a "double-wavelength specific sensitizer photoreactor". One example of this double-wavelength specific photoreactor composition is represented by the following formula: ##STR15##
Synthesis of this wavelength specific photoinitiator composition is shown in Examples 13 through 17 herein. Another double-wavelength specific sensitizer photoreactor of the present invention comprises the compound represented by the following formula: ##STR16##
It is to be understood that "R" is preferably a hydroxyl group, but it can be an alkyl group including, but not limited to, a methyl, ethyl or propyl group. The important feature of the reactive species generating portion of the molecule is the tertiary carbon atom that is in the alpha position to the carboxyl group.
It is to be understood that the above reactions are merely one method of binding a one or more wavelength sensitizers to one or more photoinitiators, and that other methods known in the art may be used.
The term "spacer molecule" is used herein to mean any molecule which aids in the bonding process. For example, a spacer molecule may assist in the bonding reaction by relieving steric hindrance. Alternatively, a spacer molecule may allow use of more reactive or more appropriate functional groups, depending upon the functional groups present in the sensitizer and photoinitiator. It is contemplated that a spacer molecule may aid in the transfer of energy from the sensitizer to the photoinitiator, by either allowing a more favorable conformation or providing a more favorable energy transfer pathway.
As noted earlier, the wavelength-specific sensitizer is adapted to have an absorption wavelength band generally corresponding to an emission peak of the radiation. In addition, the wavelength-specific sensitizer will have a high intensity of absorption. For example, the wavelength-specific sensitizer may have a molar extinction coefficient greater than about 2,000 liters per mole per cm (1 mole.sup.-1 cm.sup.-1) at an absorption maximum. As another example, the wavelength-specific sensitizer may have a molar extinction coefficient (absorptivity) greater than about 5.000 l mole.sup.-1 cm.sup.-1. As another example, the wavelength-specific sensitizer may have a molar extinction coefficient (absorptivity) greater than about 10,000 l mole.sup.-1 cm.sup.-1. As a further example, the wavelength-specific sensitizer will have a molar extinction coefficient greater than about 20,000 l mole.sup.-1 cm.sup.-1.
The absorption characteristics of the wavelength-specific sensitizer are not limited to a single wavelength band. Many compounds exhibit more than one absorption wavelength band. Consequently, a wavelength-specific sensitizer may be adapted to absorb two or more wavelength bands of radiation. Alternatively, two or more wavelength-specific sensitizers may be associated with a reactive species-generating photoinitiator. Such two or more wavelength-specific sensitizers may absorb the same wavelength band or they may absorb two or more different wavelength bands of radiation.
The method of the present invention involves generating a reactive species by exposing a wavelength specific photoreactor composition to radiation in which the wavelength specific photoreactor composition includes a wavelength-specific sensitizer associated with one or more reactive species-generating photoinitiators. In other words, the method involves providing a wavelength-specific sensitizer in association with one or more reactive species-generating photoinitiators and irradiating the wavelength-specific sensitizer.
The term "quantum yield" is used herein to indicate the efficiency of a photochemical process. More particularly quantum yield is a measure of the probability that a particular molecule will absorb a quantum of light during its interaction with a photon. The term expresses the number of photochemical events per photon absorbed. Thus, quantum yields may vary from zero (no absorption) to 1.
The sensitizer absorbs photons having a specific wavelength and transfers the absorbed energy to an associated photoinitiator which, in turn, generates a reactive species. However, the efficiency with which a reactive species is generated is significantly greater than that experienced with the reactive species-generating photoinitiator alone. For example, the wavelength specific photoreactor composition desirably will have a quantum yield greater than about 0.5. More desirably, the quantum yield of the wavelength specific photoreactor composition will be greater than about 0.6. Even more desirably, the quantum yield of the wavelength specific photoreactor composition will be greater than about 0.7. Still more desirably, the quantum yield of the wavelength specific photoreactor composition will be greater than about 0.8, with the most desirable quantum yield being greater than about 0.9.
The term "polymerization" is used herein to mean the combining, e.g. covalent bonding, of large numbers of smaller molecules, such as monomers, to form very large molecules, i.e., macromolecules or polymers. The monomers may be combined to form only linear macromolecules or they may be combined to form three-dimensional macromolecules, commonly referred to as crosslinked polymers.
As used herein, the term "curing" means the polymerization of functional oligomers and monomers, or even polymers, into a crosslinked polymer network. Thus, curing is the polymerization of unsaturated monomers or oligomers in the presence of crosslinking agents.
The terms "unsaturated monomer," "functional oligomer," and "crosslinking agent" are used herein with their usual meanings and are well understood by those having ordinary skill in the art. The singular form of each is intended to include both the singular and the plural, i.e., one or more of each respective material.
The term "unsaturated polymerizable material" is meant to include any unsaturated material capable of undergoing polymerization. The term encompasses unsaturated monomers, oligomers, and crosslinking agents. Again, the singular form of the term is intended to include both the singular and the plural.
Exposing the wavelength specific photoreactor composition of the present invention to radiation results in the generation of one or more reactive species. Thus, the wavelength specific photoreactor composition may be employed in any situation where reactive species are required, such as for the polymerization of an unsaturated monomer and the curing of an unsaturated oligomer/monomer mixture. The unsaturated monomers and oligomers may be any of those known to one having ordinary skill in the art. In addition, the polymerization and curing media also may contain other materials as desired, such as pigments, extenders, amine synergists, and such other additives as are well known to those having ordinary skill in the art.
By way of illustration only, examples of unsaturated monomers and oligomers include ethylene, propylene, vinyl chloride, isobutylene, styrene, isoprene, acrylonitrile, acrylic acid, methacylic acid, ethyl acrylate, methyl methacrylate, vinyl acrylate, allyl methacrylate, tripropylene glycol diacrylate, trimethylol propane ethoxylate acrylate, epoxy acrylates, such as the reaction product of a bisphenol A epoxide with acrylic acid; polyester acrylates, such as the reaction product of acrylic acid with an adipic acid/hexanediol-based polyester, urethane acrylates, such as the reaction product of hydroxypropyl acrylate with diphenylmethane-4,4'-diisocyanate, and polybutadiene diacrylate oligomer.
Accordingly, the present invention also comprehends a method of polymerizing an unsaturated monomer by exposing the unsaturated monomer to radiation in the presence of the efficacious wavelength specific photoreactor composition described above. When an unsaturated oligomer/monomer mixture is employed in place of the unsaturated monomer, curing is accomplished. It is to be understood that the polymerizable material admixed with the wavelength specific photoreactor composition of the present invention is to be admixed by means known in the art, and that the mixture will be irradiated with an amount of radiation sufficient to polymerize the material. The amount of radiation sufficient to polymerize the material is readily determinable by one of ordinary skill in the art, and depends upon the identity and amount of wavelength specific photoreactor composition, the identity and amount of the polymerizable material, the intensity and wavelength of the radiation, and the duration of exposure to the radiation.
The present invention further includes a film and a method for producing a film, by drawing an admixture of unsaturated polymerizable material and the wavelength specific photoreactor composition of the present invention, into a film and irradiating the film with an amount of radiation sufficient to polymerize the composition. When the unsaturated polymerizable material is an unsaturated oligomer/monomer mixture, curing is accomplished. Any film thickness may be produced, as per the thickness of the admixture formed, so long as the admixture sufficiently polymerizes upon exposure to radiation. The admixture may be drawn into a film on a nonwoven web or on a fiber, thereby providing a polymer-coated nonwoven web or fiber, and a method for producing the same. Any method known in the art of drawing the admixture into a film may be used in the present invention. The amount of radiation sufficient to polymerize the material is readily determinable by one of ordinary skill in the art, and depends upon the identity and amount of wavelength specific photoreactor composition, the identity and amount of the polymerizable material, the thickness of the admixture, the intensity and wavelength of the radiation, and duration of exposure to the radiation.
The term "fiber" as used herein denotes a threadlike structure. The fibers used in the present invention may be any fibers known in the art. The term "nonwoven web" as used herein denotes a web-like matter comprised of one or more overlapping or interconnected fibers in a nonwoven manner. It is to be understood that any nonwoven fibers known in the art may be used in the present invention.
The present invention also includes an adhesive composition comprising an unsaturated polymerizable material admixed with the wavelength specific photoreactor composition of the present invention. Similarly, the present invention includes a laminated structure comprising at least two layers bonded together with the above described adhesive composition, in which at least one layer is a cellulosic or polyolefin nonwoven web or film. Accordingly, the present invention provides a method of laminating a structure wherein a structure having at least two layers with the above described adhesive composition between the layers is irradiated to polymerize the adhesive composition. When the unsaturated polymerizable material in the adhesive is an unsaturated oligomer/monomer mixture, the adhesive is irradiated to cure the composition.
It is to be understood that any layers may be used in the present invention, on the condition that at least one of the layers allows sufficient radiation to penetrate through the layer to enable the admixture to polymerize sufficiently. Accordingly, any cellulosic or polyolefin nonwoven web or film known in the art may be used as one of the layers so long as they allow radiation to pass through. Again, the amount of radiation sufficient to polymerize the admixture is readily determinable by one of ordinary skill in the art, and depends upon the identity and amount of wavelength specific photoreactor composition, the identity aid amount of the polymerizable material, the thickness of the admixture, the identity and thickness of the layer, the intensity and wavelength of the radiation, and the duration of exposure to the radiation.
The radiation to which the wavelength specific photoreactor composition is exposed generally will have a wavelength of from about 4 to about 1,000 nanometers. Thus, the radiation may be ultraviolet radiation, including near ultraviolet and far or vacuum ultraviolet radiation; visible radiation: and near infrared radiation. Desirably, the radiation will have a wavelength of from about 100 to about 900 nanometers. More desirably, the radiation will have a wavelength of from about 100 to 700 nanometers.
Desirably, when the reactive species-generating photoinitiator is an organic compound, the radiation will be ultraviolet radiation having a wavelength of from about 4 to about 400 nanometers. More desirably, the radiation will have a wavelength of from about 100 to about 375 nanometers, and even more desirably will have a wavelength of from 200 to about 370 nanometers. For example, the radiation may have a wavelength of from about 222 to about 308 nanometers. The radiation desirably will be incoherent, pulsed ultraviolet radiation from a dielectric barrier discharge excimer lamp.
Excimers are unstable excited-state molecular complexes which occur only under extreme conditions, such as those temporarily existing in special types of gas discharge. Typical examples are the molecular bonds between two rare gaseous atoms or between a rare gas atom and a halogen atom. Excimer complexes dissociate within less than a microsecond and, while they are dissociating, release their binding energy in the form of ultraviolet radiation. The dielectric barrier excimers in general emit in the range of from about 125 nm to about 500 nm, depending upon the excimer gas mixture.
Dielectric barrier discharge excimer lamps (also referred to hereinafter as "excimer lamp") are described, for example, by U. Kogelschatz. "Silent discharges for the generation of ultraviolet and vacuum ultraviolet excimer radiation." Pure & Appl. Chem. 62. No. 9, pp. 16671674 (1990); and E. Eliasson and U. Kogelschatz, "UV Excimer Radiation from Dielectric-Barrier Discharges." Appl. Phys. B. 46, pp. 299-303 (1988). Excimer lamps Were developed by ABB Infocom Ltd., Lenzburg, Switzerland and at the present time are available from Heraeus Noblelight GmbH. Kleinostheim, Germany.
The excimer lamp emits incoherent, pulsed ultraviolet radiation. Such radiation has a relatively narrow bandwidth, i.e., the half width is of the order of approximately 5 to 100 nanometers. Desirably, the radiation will have a half width of the order of approximately 5 to 50 nanometers, and more desirably will have a half width of the order of 5 to 25 nanometers. Most desirably, the half width will be of the order of approximately 5 to 15 nanometers.
The ultraviolet radiation emitted from an excimer lamp can be emitted in a plurality of wavelengths, wherein one or more of the wavelengths within the band are emitted at a maximum intensity. Accordingly, a plot of the wavelengths in the band against the intensity for each wavelength in the band produces a bell curve. The "half width" of the range of ultraviolet radiation emitted by an excimer lamp is defined as the width of the bell curve at 50% of the maximum height of the bell curve.
The emitted radiation of an excimer lamp is incoherent and pulsed, the frequency of the pulses being dependent upon the frequency of the alternating current power supply which typically is in the range of from about 20 to about 300 kHz. An excimer lamp typically is identified or referred to by the wavelength at which the maximum intensity of the radiation occurs, which convention is followed throughout this specification and the claims. Thus, in comparison with most other commercially useful sources of ultraviolet radiation which typically emit over the entire ultraviolet spectrum and even into the visible region, excimer lamp radiation is essentially monochromatic.
As a result of the arylketoalkene wavelength-specific sensitizer of the present invention absorbing radiation in the range of about 250 to about 350 nanometers, and more particularly at about 270 to 320 nanometers, the wavelength specific photoreactor composition of the present invention will generate one or more reactive species upon exposure to sunlight. According, this wavelength specific photoreactor composition of the present invention provides a method for the generation of reactive species that does not require the presence of a special light source. This wavelength specific photoreactor composition of the present invention having the arylketoalkene sensitizer enables the production of adhesive and coating compositions that consumers can apply to a desired object and polymerize or cure upon exposure to sunlight. This wavelength specific photoreactor composition also enables numerous industry applications wherein unsaturated polvmerizable materials may be polymerized merely upon exposure to sunlight. Therefore, depending upon how the wavelength specific photoreactor composition is designed, the wavelength specific photoreactor composition of the present invention having the arylketoalkene sensitizer can eliminate the cost of purchasing and maintaining light sources in numerous industries wherein such light sources are necessary without the wavelength specific photoreactor composition of the present invention.
The wavelength specific photoreactor compositions of the present invention also differ from the prior art in that the prior art sensitizers absorb a wide bandwidth of radiation. In fact, the prior art photoinitiators are designed to absorb as much radiation as possible over as wide a range as possible thereby increasing the efficiency of the photoinitiators when exposed to ordinary light. Whereas the sensitizer of the present invention absorbs a single wavelength of radiation. The use of a wavelength specific photoreactor composition capable of absorbing at a substantially single wavelength of radiation results in an extremely efficient photoreactor upon exposure to a very narrow bandwidth of radiation or upon exposure to a single wavelength of radiation.
As shown in the Examples below, the superiority of the wavelength specific photoreactor compositions of the present invention over known photoinitiators is clear, even when the radiation is not the essentially monochromatic emission. The effective tuning of the wavelength specific photoreactor composition for a specific wavelength band permits the wavelength specific photoreactor composition to more efficiently utilize the target radiation in the emission spectrum of the radiating source corresponding to the "tuned" wavelength band, even though the intensity of such radiation may be much lower than, for example, radiation from a narrow band emitter, such as an excimer lamp. In other words, the effectiveness of the wavelength specific photoreactor composition of the present invention is not necessarily dependent upon the availability or use of a narrow wavelength band radiation source.
Also, as shown in Example 4, the single-photoinitiator photoreactor of the present invention is exceptionally efficient. In Example 4, a mixture of GENOMER.RTM. 1500B with a concentration of only about 0.5% of the single-photoinitiator photoreactor produced in Example 3 is totally cured upon exposure to the excimer lamp. The concentration of wavelength specific photoreactor composition used in Example 4 is substantially lower than the amounts normally used in the prior art. Typical concentrations of conventional photoreactors or photoinitiators in the prior art are between approximately 2% to 20% by weight.
Further, as shown in Example 7, the multi-photoinitiator photoreactors of the present invention are even more efficient than the single-photoinitiator photoreactors of the present invention. More particularly, Table 2 summarizes the curing times for a pigmented polymerizable formulation, wherein either a commercial photoinitiator product, the wavelength specific photoreactor composition produced in Example 3 or the wavelength specific photoreactor composition produced in Example 6 is admixed therein. The wavelength specific photoreactor composition produced in Example 6 had the shortest curing time, namely, 0.06 seconds. The wavelength specific photoreactor composition produced in Example 3 had a curing time of 0.10, and the commercial photoinitiator had a cure time that is 50 times greater than the wavelength specific photoreactor composition of Example 6, namely 3.0 seconds.
Accordingly, a major advantage of the wavelength specific photoreactor compositions of the present invention is that they have rapid curing times in comparison to the curing times of the prior art. Another advantage of the of the present invention is that the multi-photoinitiator photoreactors of the present invention have even faster curing times in comparison to the single-photoinitiator photoreactors of the present invention. Yet another advantage of the present invention is that the multi-sensitizer photoreactors and the multi-photoinitiator photoreactors of the present invention are highly sensitive photoreactors and are beneficially used in situations having lower light levels.
The present invention is further described by the examples which follow. Such examples, however, are not to be construed as limiting in any way either the spirit or the scope of the present invention. In the examples, all parts are by weight, unless stated otherwise.
EXAMPLE 1
This example describes a method of synthesizing the following wavelength-specific sensitizer: ##STR17##
The wavelength-specific sensitizer is produced as summarized below: ##STR18##
To a 250 ml round bottom flask fitted with a magnetic stir bar, and a condenser, is added 10.8 g (0.27 mole) sodium hydroxide (Aldrich), 98 g water and 50 g ethanol. The solution is stirred while being cooled to room temperature in an ice bath. To the stirred solution is added 25.8 g (0.21 mole) acetophenone (Aldrich) and then 32.2 g (0.21 mole) 4-carboxybenzaldehyde (Aldrich). The reaction mixture is stirred at room temperature for approximately 8 hours. The reaction mixture temperature is checked in order to prevent it from exceeding 30.degree. C. Next, dilute HCl is added to bring the mixture to neutral pH as indicated by universal pH indicator paper. The white/yellow precipitate is filtered using a Buchner funnel to yield 40.0 g (75%) after drying on a rotary pump for four hours. The product is used below without further purification.
The resulting reaction product had the following physical parameters:
Mass. Spec. m/e (m.sup.+) 252, 207, 179, 157, 105, 77, 51.
The ultraviolet radiation spectrum of the product had an extinction coefficient of about 24,000 at about 304 nanometers, and .lambda..sub.max is at 308 nanometers.
EXAMPLE 2
This example describes a method of making the following wavelength-selective sensitizer, namely 4-[4'-carboxy phenyl]-3-buten-2-one: ##STR19##
The wavelength-specific sensitizer is produced as summarized below: ##STR20##
The method of Example 1 is followed except that acetone (Fisher, Optima Grade) is added first, and then the carboxybenzaldehyde is added. More particularly, 32.2 g (0.21 mole) of carboxybenzaldehyde is reacted with 12.2 g (0.21 mole) of acetone in the sodium hydroxide/ethanol/water mixture described in Example 1. Dilute HCl is added to bring the reaction mixture to neutral pH, yielding 37.1 g (91%) of a pale yellow powder which is used without further purification in the following examples.
The resulting reaction product, namely 4-[4'-carboxy phenyl]-3-buten-2-one, had the following physical parameters:
Mass. Spec. 190 (m.sup.+), 175, 120.
EXAMPLE 3
This example describes a method of covalently bonding the compound produced in Example 2 to a photoinitiator, namely IRGACURE.RTM. 2959 (1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one or 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone), as is summarized below: ##STR21##
To a 500 ml round bottom flask fitted with a magnetic stir bar, and condenser, is placed 20 g (0.08 mole) of the composition prepared in Example 28, 17.8 g (0.08 mole) IRGACURE.RTM. 2959 (Ciba-Geigy, N.Y.), 0.5 g p-toluenesulfonic acid (Aldrich), and 300 ml anhydrous benzene (Aldrich). The Dean and Stark adapter is put on the flask and the reaction mixture heated at reflux for 8 hours after which point 1.5 ml of water had been collected (theo. 1.43 ml). The reaction mixture is then cooled and the solvent removed on a rotary evaporator to yield 35.4 g. The crude product is recrystallized from 30% ethyl acetate in hexane to yield 34.2 g (94%) of a white powder. The resulting reaction product had the following physical parameters:
Mass. Spectrum: 458 (m.sup.+), 440, 399, 322, 284.
EXAMPLE 4
The following experiment tested the curing ability of the compound produced in Example 3. More particularly, the compound produced in Example 3 is mixed with the difunctional alkyl urethane acrylate adhesive GENOMER.RTM. 1500B (Mader, Biddle Sawyer Corporation, New York. N.Y.) and exposed to 308 nm excimer lamp on a conveyor belt. Two formulations are studied:
Formulation I
About 0.05 g of the compound produced in Example 3 is mixed with 10 g of GENOMER.RTM. 1500B. Therefore the concentration of the compound produced in Example 3 in the mixture is about 0.5%. These components are mixed by means of a magnetic stirring bar at 80.degree. C. A few drops of the mixture is placed on a heated metal plate (Q-Panel Company, Westlake, Ohio) and drawn down to a thickness of about 0.1 mm by means of a 0 draw-down bar (Industry Tech., Oldsmar, Fla.).
Formulation II
About 0.025 g of IRGACURE.RTM. 2959 is mixed with 10 g of GENOMER.RTM. 1500B. These components are mixed and then drawn out on heated metal plates with a 0 draw-down bar as per Formulation I.
Each plate is then exposed to a 308 nanometer excimer lamp on a conveyor belt for approximately 0.8 seconds. The conveyor belt is set at 50 feet/minute. The plate having Formulation I thereon is totally cured upon exposure to the excimer lamp. In contrast, the plate having Formulation II thereon remained tacky and is not fully cured.
EXAMPLE 5
This example describes the evaluation of the curing behavior of an adhesive containing the wavelength specific photoreactor compositions of Example 3 as reported in Example 4 upon exposure to ultraviolet radiation from an excimer lamp.
An excimer lamp configured substantially as described by Kozelschatz and Eliasson et al., supra. is employed and is shown diagrammatically in FIG. 1. With reference to FIG. 1, the excimer lamp 100 consisted of three coaxial quartz cylinders and two coaxial electrodes. The outer coaxial quartz cylinder 102 is fused at the ends thereof to a central coaxial quartz cylinder 104 to form an annular discharge space 106. An excimer-forming gas mixture is enclosed in the annular discharge space 106. An to inner coaxial quartz cylinder 108 is placed within the central cylinder 104. The inner coaxial electrode 110 consisted of a wire wound around the inner cylinder 108. The outer coaxial electrode 112 consisted of a wire mesh having a plurality of openings 114. The inner coaxial electrode 110 and outer coaxial electrode 112 are connected to a high voltage generator 116. Electrical discharge is maintained by applying an alternating high voltage to the coaxial electrodes 110 and 112. The operating frequency is 40 kHz, the operating voltage 10 kV. Cooling water is passed through the inner coaxial quartz cylinder 108, thereby maintaining the temperature at the outer surface of the lamp at less than about 120.degree. C. The resulting ultraviolet radiation is emitted through the openings 114 as shown by lines 118. The lamp is used as an assembly of four lamps 100 mounted side-by-side in a parallel arrangement.
A film of adhesive is deemed cured completely, i.e., through the entire thickness of the film, when it passed the scratch test; see, e.g., M. Braithwaite et al., "Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints," Vol. IV, SITA Technology Ltd., London, 1991, pp. 11-12.
EXAMPLE 6
This example describes a method of covalently bonding two photoinitiators, namely IRGACURE.RTM. 2959, to a chalcone sensitizer of the present invention, as is summarized below in a two step reaction: ##STR22## Step A
To a 250 ml round bottom flask fitted with a magnetic stir bar is added 5.4 g sodium hydroxide (Aldrich), 5 ml water, and 45 ml ethanol, and the solution is cooled in a water bath. When the reaction mixture is at room temperature, 15.7 g (0.10 mole) carboxybenzaldehyde (Aldrich), and 17.2 g (0.10 mole) acetylbenzoic acid (Aldrich) are added and the solution stirred overnight (12 hours). The reaction mixture is then chilled in an ice bath and the solution neutralized/acidified with dilute HCl until pH indicator paper showed a pH of 3 to 5. The yellow precipitate is filtered and the solid is dried overnight in a vacuum desiccator. The product of this reaction is the di-carboxylic acid substituted chalcone illustrated above. The yield is 28.1 grams (90%).
Step B
In a 500 ml round bottom flask flushed out by argon is placed a magnetic stir bar, 23.6 g (0.08 mole) of the di-carboxylic acid substituted chalcone produced above in step A, 200 ml of dry dichloromethane (Aldrich), 35.6 g (0.16 mole) IRGACURE.RTM. 2959 (Ciba-Geigy), and 0.8 g dimethylaminopyridine (Aldrich). The reaction mixture is cooled in an ice bath to 0.degree. C., and then 18.4 g of DCC (Aldrich) is added over 5 minutes and the solution is allowed to warm to room temperature, and is stirred overnight. The reaction mixture is filtered and washed with 0.5 N HCl aqueous followed by saturated NaHCO.sub.3 solution. The organic layer is separated, dried (Na.sub.2 SO.sub.4) and the solvent removed under reduced pressure to yield a pale yellow solid. The product is the multi-photoinitiator photoreactor illustrated above. The yield is 51.8 g (91%).
The resultant reaction product had the following physical parameters:
.sup.1 H NMR [CDCL.sub.3 ] .delta. 1.7 [s], 4.0 [d], 4.2 [d], 7.0 [d], 7.2-8.2 [nu].
Note that the ratio of CH.sub.3 to CH.dbd.CH is 12 to 2, thus indicating that there are two IRGACURE.RTM. 2959 to one mole of chalcone.
EXAMPLE 7
The following experiment tested the curing ability of the wavelength specific photoreactor composition produced in Example 6 in comparison to the wavelength specific photoreactor composition produced in Example 3 and to a commercially available photoinitiator product. More particularly, the same formulation to be cured is mixed with a commercial initiator product (3.5% IRGACURE.RTM. 907 with 3.5% ITX coinitiator, by weight), or with the wavelength specific photoreactor composition produced in Example 3, or with the wavelength specific photoreactor composition produced in Example 6. Each mixture is drawn into a 50 micron film and then cured. The formulation is an offset press formulation of a high molecular weight urethane acrylate having a molecular weight of above 100,000. Also, as the formulation is thixotropic, the formulation also contains approximately 5% clay.
More specifically, approximately 2 grams of the formulation for offset presses is placed in an aluminum pan and the corresponding weight of the appropriate photoinitiator then added to give a 6 to 7% concentration by weight of the photoinitiator. Table 2 reports the concentrations of each of the photoreactors in their respective formulation mixtures. The mixture is heated on a hot plate set at a low heat and the mixture stirred for five minutes to ensure mixing. A small amount of the mixture is then placed on a Q-Panel (3 inch by 5 inch) plate and drawn down to a film thickness of 50 microns using an `O` or "3" bar. The plate is then placed under a 308 nm excimer lamp and exposed the light until the mixture is cured, as determined by the scratch and twist test. The excimer lamp has an input power of approximately 2.5 kilowatts, and an output power of approximately 0.1 watt per square centimeter per lamp bulb.
Table 1 summarizes the curing times for the clear coating. As shown below, the wavelength specific photoreactor compositions of the present invention, as produced in Examples 3 and 6, had cure times of only 0.04 seconds, wherein the commercial photoinitiator had a cure time that is 40 times greater, namely, 1.6 seconds.
TABLE 1______________________________________Cured Offset PressCoatings* Cure Time(50 micron film) (Sec)______________________________________Clear Coating 1.6(Commercial Initiator)Clear Coating 0.04(Example 3 Photoreactor)Clear Coating 0.04(Example 6 Photoreactor)______________________________________ *Paste formulations which contain a clay agent to introduce thixotropic properties
Table 2 summarizes the curing times for a pigmented coating, wherein the formulation described above is further admixed with 15% by weight of a green pigment, namely, Gamma Cure. As shown below, the wavelength specific photoreactor composition produced in Example 6 had the shortest curing time, namely, 0.06 seconds. The wavelength specific photoreactor composition produced in Example 3 had a curing time of 0.10, and the commercial photoinitiator had a cure time that is 50 times greater than the wavelength specific photoreactor composition of Example 6, namely 3.0 seconds.
TABLE 2______________________________________Cured Offset PressCoatings* Cure Time Conc. of(50 micron film) (Seconds) Photoreactor______________________________________Clear Coating 3.0 7%(Commercial Initiator)Clear Coating 0.10 6%(Example 3 Photoreactor)Clear Coating 0.06 6%(Example 6 Photoreactor)______________________________________ *Paste formulations which contain a clay agent to introduce thixotropic properties
EXAMPLE 8
The following experiment tested the curing ability of the wavelength specific photoreactor composition produced in Example 6 in comparison to the wavelength specific photoreactor composition produced in Example 3 and to a commercially available photoinitiator product, wherein the power setting for the excimer lamp is varied. With the exception of varying the power setting of the excimer lamp, all other aspects of the experiment are described in Example 7. Table 3 summarizes the curing times for the clear and pigmented formulations, wherein "full" represents full lamp power, "0.75" represents 75% lamp power, etc.
TABLE 3______________________________________ Excimer Lamp Power SettingSample Full 0.75 0.50 0.25______________________________________CommercialInitiator 7%Clear 1.6 2.0 2.5 4.0Pigmented 3.0 5.0 7.5 15.0Example 3Photoreactor 6%Clear 0.04 0.08 0.10 0.26Pigmented 0.10 0.14 0.22 0.34Example 6Photoreactor 6%Clear 0.04 0.06 0.12 0.16Pigmented 0.04 0.08 0.18 0.20______________________________________
EXAMPLE 9
Examples 9 through 12 describe the synthesis of the wavelength specific photoreactor composition shown as the reaction product in Example 12.
In a 1 liter 3-necked round bottomed flask fitted with a mechanical stirrer and condenser, is placed 200 g (1.56 moles) of cyclohexyl carboxylic acid (Aldrich) and 223 g (1.2 eq) of thionyl chloride (Aldrich). The reaction mixture is stirred and heated to reflux. 50 ml of toluene is added to allow the reaction mixture to become a solution. After 1 hour, 300 ml of dry toluene is added and the solvent is distilled off. 200 ml of toluene with a small amount of thionyl chloride is distilled off and the distillate has a steady boiling point of approximately 110.degree. C. The condenser is then mounted back for reflux and 300 ml of dry toluene is added along with 141 g (1.5 moles) of phenol (Aldrich) and the mixture is refluxed for 12 hours. The solvent is then removed under reduced pressure to leave a pale brown oil. The yield is 287 g (94%). ##STR23##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 1.2-2.8 (m), 1.8 (m), 2.0(m), 6.9-7.5 (m), ppm.
HPLC 90% Ch.sub.3 CN/10% H.sub.2 O--C.sub.18 Column: Retention time of 5.8 minutes
EXAMPLE 10
To a 1 liter 3-necked round bottom flask fitted with a mechanical stirrer, condenser and flushed with argon, is added 65.2 a of aluminum chloride (Aldrich), 100 ml of carbon disulfide (Aldrich). To this stirred suspension is slowly added 100 g (0.69 moles) of the ester from Example 9, and the mixture is stirred under reflux overnight (12 hours). The mixture is then a thick brown sludge which is broken up by the addition of dilute HCl. The reaction mixture is poured into a separatory funnel and extracted three times with 150 ml each of ether. The ether extracts are combined, washed with ice cold water, dried over MgSO.sub.4 and the ether is removed to give 95 g (95% yield) of a thick light brown oil. ##STR24##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 0.8-2.3 (m), 3.7 (s), 2.0(m), 7.2-7.7 (m), ppm.
EXAMPLE 11
In a 1 liter, 3 necked round bottomed flask fitted with a mechanical stirrer and a condenser, an inlet gas tube and a bubbler fitted to the condenser, is placed 90 g (0.44 moles) of the ketophenol from Example 10, and 300 ml of dry tetrahydrofuran. The reaction mixture is chilled in a salt/ice bath and 98.5 g (0.88 moles) of potassium t-butoxide is added. After 20 minutes, a stream of dry oxygen is bubbled into the reaction mixture for 2 hours. The reaction mixture is then neutralized with dilute HCl and then extracted three times each with 100 ml of ether. The combined extracts are then washed with water, dried over MgSO.sub.4 and the solvent removed under reduced pressure to yield 95.2 g of a thick oil (98% yield). ##STR25##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 0.8-2.3 (m), 3.7 (s), 2.0(m), 4.6 (s), 7.2-7.7 (7m), ppm.
EXAMPLE 12
In a 1 liter, 3-necked round bottomed flask fitted with a mechanical stirrer and a condenser is placed 50 g (0.2 moles of the product from Example 6 and 23.6 g (0.2 moles) of thionyl chloride and 50 mls of dry toluene. The reaction mixture is heated to reflux for 2 hours after which the condenser is turned to allow distillation of the toluene and any unreacted thionyl chloride. An additional 150 ml of toluene is added and 100 ml allow-ed to be distilled giving a steady 110.degree. C. boiling point. 200 ml of fresh, dry toluene is added and the condenser adjusted to its reflux position. ##STR26##
To the reaction mixture is slowly added 44 g (0.2 moles) of the diol from Example 11 and the mixture is allowed to reflux for 12 hours. The solution is then removed under reduced pressure to yield 86.7 g (95% yield) of a light yellow solid. The solid is recrystalized from benzene to yield a yellow crystalline material with a melting point of 127-128.degree. C. ##STR27##
EXAMPLE 13
Examples 13 through 17 describe the synthesis of the double-wavelength specific sensitizer photoreactor shown as the product in Example 17.
In a 500 ml round bottomed flask fitted with a magnetic stirrer and a condenser is placed 122.1 g of sodium hydroxide, 100 ml of water, and 100 ml of ethanol. The solution is stirred and 125 g (0.73 mole) of ethyl 4-hydroxycyclohexane carboxylate is added. The solution refluxed for 2 hours, cooled and the solution is neutralized with dilute HCl. The solution is then extracted three times with 100 ml of ether (3.times.100 ml). The ether is separated, dried (MgSO.sub.4) and removed under reduced pressure to yield 100 g of a white powder. (95.1 % yield) ##STR28##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 1.5-1.7 (m), 1.8 (m), 2.0(m), 3.8 (m), 4.8-5.0 (m) ppm.
EXAMPLE 14
To a 3 necked round bottom flask (500 ml) fitted with a mechanical stirrer and a condenser, is placed 90 g (0.62 moles) of 4-hydroxycyclohexyl carboxylic acid and 89.2 g of thionyl chloride, and the mixture is stirred for one hour before heating to reflux. On reflux, 80 ml of dry toluene is added and the mixture stirred for an additional hour. 100 ml of toluene is added and the liquid distilled to remove any excess thionyl chloride. After 50 ml is distilled, another 50 ml of toluene is added, and the distillation continued until 120 ml of toluene/thionyl chloride is collected. ##STR29##
The distillation is stopped and the condenser is fitted for reflux. To the mixture is added 100 ml of toluene and 58.3 g (0.62 moles) of phenol and the reaction mixture refluxed for 12 hours. The solvent is then removed under reduced pressure to yield 113 g (83%) of a light yellow oil. ##STR30##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ]1.6-3.0 (m), 6.8-7.5 (m) ppm
EXAMPLE 15
To a 3 necked 500 ml round bottom flask fitted with a mechanical stirrer and a condenser, is placed 60.4 g (0.45 moles) anhydrous aluminum chloride and 100 ml of carbon disulfide. To this mixture is slowly added 100 g (0.45 moles) of the ester from Example 14. The mixture is stirred for one hour and then heated to reflux for eight hours. The reaction is cooled and dilute HCl is added slowly and the mixture stirred for two hours. The reaction mixture is poured into a separatory funnel and extracted three times with 100 ml with ether. The organic layer is then removed to yield an oil (95 g, 86% yield). ##STR31##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 1-3 (m), 6.8-7.6 (m), ppm.
EXAMPLE 16
In a 500 ml round bottom flask fitted with a mechanical stirrer and a condenser and being flushed with dry argon is placed 137.8 g (1.23 moles) potassium t-butoxide, 200 ml of dry tetrahydrofuran and the solution chilled in a salt-ice bath. 90 g (0.41 moles) is added and the solution stirred for 30 minutes. Dry air is then bubbled into the solution for 2 hours. The solution is quenched with 50 ml water and neutralized with dilute HCl. The reaction mixture is extracted with ether (3.times.100 ml), and the ether and solvents removed to yield 90.1 g (93% yield) of the triol. ##STR32##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 1-3 (m), 6.8-7.6 (m), ppm.
EXAMPLE 17
To a solution of 183.8 g (0.78 moles) of the acid chloride from Example 12 in 300 ml of toluene in a 2 liter 3-necked flask fitted with a condenser and mechanical stirrer, is added 80.0 g (0.36 moles) of the triol and the solution is refluxed for 8 hours. Removal of the toluene gave a light yellow powder which is recrystallized from benzene to yield 201.1 g (84%) of pale yellow crystals. ##STR33##
The resulting reaction product had the following physical parameters:
.sup.1 H NMR [CDCl.sub.3 ] .delta. 1.5-2.8 (m), 7.6-9.7 (m), ppm.
EXAMPLE 18
The cure rate of off-set press black ink is checked using the new compound from Example 17 under an excimer lamp (308 nm radiation).
1. A 5% wt/wt mixture of 14% black pigmented off-set press ink is made with the compound from Example 17 in an aluminum pan and heated to ensure good mixing. The black ink is drawn out on a hot (60.degree. C.) plate using a zero-draw-down bar to give a film of 20-30 micron thickness. The film is exposed to 0.1 seconds flash of 308 nm excimer lamp radiation and the degree of cure determined by scratch and twist analysis.
The thinner parts of the film had a total cure, and the thicker parts had a skin cure.
2. A 2.5% wt/wt ink is made as previously described and drawn down with the zero draw-down bar. The ink is exposed to 0.1 seconds of 308 nm radiation resulting in a complete cure of the film.
Using a higher concentration (5%) of the compound from Example 17, apparently is too high a concentration and the double antenna system shields the layer before and gives slower curing. It is believed that the antenna system shields the layers below and gives slow curing.
While the specification has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Accordingly, the scope of the present invention should be assessed as that of the appended claims and any equivalents thereto.
Claims
  • 1. A wavelength specific photoreactor comprising one or more wavelength-specific sensitizing moieties covalently bonded to one or more reactive species-generating photoinitiating moieties,
  • wherein each photoinitiating moiety of the photoreactor is derived from a photoinitiator represented by one of the following formulae: ##STR34## wherein each sensitizing moiety of the photoreactor is derived from a chalcone, benzilidene acetone, or phthaloylglycine; and wherein the photoreactor contains more than one sensitizing moiety or more than one photoinitiating moiety.
  • 2. The wavelength specific photoreactor of claim 1, wherein the one or more reactive species-generating photoinitiating moieties are covalently bonded to the one or more wavelength-specific sensitizing moieties by one or more spacer groups bonded to the photoinitiating moieties, sensitizing moieties or both.
  • 3. The wavelength specific photoreactor of claim 2, wherein the one or more spacer groups comprise a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group prior to covalent bonding.
  • 4. The wavelength specific photoreactor of claim 2, wherein two sensitizing moieties are covalently bonded to one photoinitiating moiety.
  • 5. The wavelength specific photoreactor of claim 4, wherein the photoreactor is represented by the following formula ##STR35## wherein R is a hydroxyl group, methyl group, ethyl group, or propyl group.
  • 6. The wavelength specific photoreactor of claim 4, wherein the photoreactor is represented by the following formula ##STR36##
  • 7. A method of generating a reactive species, comprising providing a wavelength specific photoreactor comprising one or more wavelength-specific sensitizing moieties covalently bonded to one or more reactive species-generating photoinitiating moieties, wherein each photoinitiating moiety is derived from a photoinitiator represented by one of the following formulae: ##STR37## wherein each sensitizing moiety is derived from a chalcone, benzilidene acetone, or phthaloylglycine; and wherein the photoreactor contains more than one sensitizing moiety or more than one photoinitiating moiety; and
  • irradiating the photoreactor.
  • 8. The method of claim 7, wherein the one or more reactive species-generating photoinitiating moieties are covalently bonded to the one or more wavelength-specific sensitizing moieties by one or more spacer groups bonded to the photoinitiating moieties, sensitizing moieties or both.
  • 9. The method of claim 8, wherein the one or more spacer groups comprise a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group prior to covalent bonding.
  • 10. The method of claim 8, wherein two sensitizing moieties are covalently bonded to one photoinitiating moiety.
  • 11. The method of claim 10, wherein the wavelength specific photoreactor is represented by the following formula ##STR38## wherein R is a hydroxyl group, methyl group, ethyl group, or propyl group.
  • 12. The method of claim 10, wherein the wavelength specific photoreactor is represented by the following formula ##STR39##
  • 13. A photoreactor comprising at least one wavelength-specific sensitizing moiety covalently bonded to at least one reactive species-generating photoinitiating moiety, said photoreactor being represented by the following formula:
  • (PM).sub.x (L).sub.z (SM).sub.y
  • wherein SM represents the wavelength-specific sensitizing moiety, PM represents the photoinitiating moiety; L is a spacer group; x and y are independently 1 or 2; x+y is equal to three; z is equal to 0 or 1; and wherein PM is ##STR40##
  • 14. The photoreactor of claim 13, wherein L comprises a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group prior to covalent bonding.
  • 15. A photoreactor comprising at least one wavelength-specific sensitizing moiety covalently bonded to at least one reactive species-generating photoinitiating moiety, said photoreactor being represented by the following formula:
  • (PM).sub.x (L).sub.z (SM).sub.y
  • wherein SM represents the wavelength-specific sensitizing moiety, PM represents the photoinitiating moiety; L is a spacer group; x and y are independently 1 or 2; x+y is equal to three; z is equal to 0 or 1; and wherein SM comprises a chalcone, benzilidene acetone, or phthaloylglycine.
  • 16. The photoreactor of claim 15, wherein L comprises a carboxylic acid group, an aldehyde group, an amino group, a haloalkyl group, a hydroxyl group, or a thioalkyl group prior to covalent bonding.
  • 17. A method of polymerizing an unsaturated polymerizable material, comprising irradiating an admixture of an unsaturated polymerizable material and the wavelength specific photoreactor of claim 1.
  • 18. A polymer film, produced by the process of:
  • providing an admixture of an unsaturated polymerizable material and the wavelength specific photoreactor of claim 1 that has been drawn into a film; and
  • irradiating the film with an amount of radiation sufficient to polymerize the admixture.
  • 19. A polymer-coated nonwoven web, produced by the process of:
  • providing a nonwoven web coated with an admixture of unsaturated polymerizable material and the wavelength specific photoreactor of claim 1; and
  • irradiating the coated web with an amount of radiation sufficient to polymerize the admixture.
  • 20. A polymer-coated fiber, produced by the process of:
  • providing a fiber coated with an admixture of unsaturated polymerizable material and the wavelength specific photoreactor of claim 1; and
  • irradiating the coated fiber with an amount of radiation sufficient to polymerize the admixture.
  • 21. A method of preparing a polymer film, comprising:
  • providing an admixture of unsaturated polymerizable material and the wavelength specific photoreactor of claim 1 that has been drawn into a film; and
  • irradiating the film with an amount of radiation sufficient to polymerize the admixture.
  • 22. A method of coating a nonwoven web comprising:
  • providing a nonwoven web coated with an admixture of unsaturated polymerizable material and the wavelength specific photoreactor of claim 1; and
  • irradiating the coated web with an amount of radiation sufficient to polymerize the admixture.
  • 23. A method of coating a fiber, comprising:
  • providing a fiber coated with an admixture of unsaturated polymerizable material and the wavelength specific photoreactor of claim 1; and
  • irradiating the coated fiber with an amount of radiation sufficient to polymerize the admixture.
  • 24. An adhesive composition comprising:
  • an unsaturated polymerizable material admixed with the wavelength specific photoreactor of claim 1,
  • wherein the adhesive is polymerizable upon exposure to radiation.
  • 25. A laminated structure comprising at least two layers bonded together with an adhesive composition, in which at least one layer is a cellulosic or polyolefin nonwoven web or film,
  • wherein the adhesive composition comprises an unsaturated polymerizable material and the wavelength specific photoreactor of claim 1, wherein the adhesive composition has been polymerized by exposure to radiation.
  • 26. A method of laminating a structure,
  • providing a structure comprising at least two layers, in which at least one layer is a cellulosic or polyolefin nonwoven web or film, with an adhesive composition between said layers, and
  • irradiating the adhesive composition to polymerize the adhesive composition,
  • wherein the adhesive composition comprises an unsaturated polymerizable material admixed with the wavelength specific photoreactor of claim 1.
CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. Ser. No. 08/625,737 filed Mar. 29, 1996, now abandoned, which is a continuation-in-part application of U.S. Ser. No. 08/537,593 filed Oct. 2, 1995, now abandoned which is incorporated herein by reference, which is a continuation-in-part of U.S. patent application Ser. No. 08/463,188, filed Jun. 5, 1995, now U.S. Pat. No. 5,739,175, which is incorporated herein by reference, which is a continuation-in-part of U.S. Ser. No. 08/327,077, filed Oct. 21, 1994, now abandoned which is incorporated herein by reference, which is a continuation-in-part application of U.S. Ser. No. 08/268,685, filed Jun. 30, 1994, now abandonded which is herein incorporated by reference.

US Referenced Citations (634)
Number Name Date Kind
RE28225 Heseltine et al. Nov 1974
RE28789 Chang Apr 1976
575228 Von Gallois Jan 1897
582853 Feer May 1897
893636 Maywald Jul 1908
1013544 Fuerth Jan 1912
1325971 Akashi Dec 1919
1364406 Olsen Jan 1921
1436856 Brenizer et al. Nov 1922
1744149 Staehlin Jan 1930
1803906 Krieger et al. May 1931
1844199 Bicknell et al. Feb 1932
1876880 Drapal Sep 1932
1880572 Wendt et al. Oct 1932
1880573 Wendt et al. Oct 1932
1916350 Wendt et al. Jul 1933
1916779 Wendt et al. Jul 1933
1955898 Wendt et al. Apr 1934
1962111 Bamberger Jun 1934
2005378 Kiel Jun 1935
2005511 Stoll et al. Jun 1935
2049005 Gaspar Jul 1936
2054390 Rust et al. Sep 1936
2058489 Murch et al. Oct 1936
2062304 Gaspar Dec 1936
2090511 Crossley et al. Aug 1937
2097119 Eggert Oct 1937
2106539 Schnitzspahn Jan 1938
2111692 Saunders et al. Mar 1938
2125015 Gaspar Jul 1938
2130572 Wendt Sep 1938
2132154 Gaspar Oct 1938
2145960 Wheatley et al. Feb 1939
2154996 Rawling Apr 1939
2159280 Mannes et al. May 1939
2171976 Erickson Sep 1939
2181800 Crossley et al. Nov 1939
2185153 Lecher et al. Dec 1939
2220178 Schneider Nov 1940
2230590 Eggert et al. Feb 1941
2237885 Markush et al. Apr 1941
2243630 Houk et al. May 1941
2268324 Polgar Dec 1941
2281895 van Poser et al. May 1942
2328166 Poigar et al. Aug 1943
2346090 Staehle Apr 1944
2349090 Haddock May 1944
2356618 Rossander et al. Aug 1944
2361301 Libby, Jr. et al. Oct 1944
2364359 Kienle et al. Dec 1944
2381145 von Glahn et al. Aug 1945
2382904 Federsen Aug 1945
2386646 Adams et al. Oct 1945
2402106 von Glahn et al. Jun 1946
2416145 Biro Feb 1947
2477165 Bergstrom Jul 1949
2527347 Bergstrom Oct 1950
2580461 Pearl Jan 1952
2601669 Tullsen Jun 1952
2612494 Von Glahn et al.. Sep 1952
2612495 Von Glahn et al. Sep 1952
2628959 Von Glahn et al. Feb 1953
2647080 Joyce Jul 1953
2680685 Ratchford Jun 1954
2728784 Tholstrup et al. Dec 1955
2732301 Robertson et al. Jan 1956
2744103 Koch May 1956
2757090 Meugebauer et al. Jul 1956
2763550 Lovick Sep 1956
2768171 Clarke et al. Oct 1956
2773056 Helfaer Dec 1956
2798000 Monterman Jul 1957
2809189 Stanley et al. Oct 1957
2827358 Kaplan et al. Mar 1958
2834773 Scalera et al. May 1958
2875045 Lurie Feb 1959
2892865 Giraldi et al. Jun 1959
2897187 Koch Jul 1959
2936241 Sharp et al. May 1960
2940853 Sagura et al. Jun 1960
2955067 McBurney et al. Oct 1960
2992129 Gauthier Jul 1961
2992198 Funahashi Jul 1961
3030208 Schellenberg et al. Apr 1962
3071815 MacKinnon Jan 1963
3075014 Palopoli et al. Jan 1963
3076813 Sharp Feb 1963
3104973 Sprague et al. Sep 1963
3114634 Brown et al. Dec 1963
3121632 Sprague et al. Feb 1964
3123647 Duennenberger et al. Mar 1964
3133049 Hertel et al. May 1964
3140949 Sprague et al. Jul 1964
3154416 Fidelman Oct 1964
3155509 Roscow Nov 1964
3175905 Wiesbaden Mar 1965
3178285 Anderau et al. Apr 1965
3238163 O'Neill Mar 1966
3242215 Heitmiller Mar 1966
3248337 Zirker et al. Apr 1966
3266973 Crowley Aug 1966
3282886 Gadecki Nov 1966
3284205 Sprague et al. Nov 1966
3300314 Rauner et al. Jan 1967
3304297 Wegmann et al. Feb 1967
3305361 Gaynor et al. Feb 1967
3313797 Kissa Apr 1967
3330659 Wainer Jul 1967
3341492 Champ et al. Sep 1967
3359109 Harder et al. Dec 1967
3361827 Biletch Jan 1968
3363969 Brooks Jan 1968
3385700 Willems et al. May 1968
3397984 Williams et al. Aug 1968
3415875 Luethi et al. Dec 1968
3418118 Thommes et al. Dec 1968
3445234 Cescon et al. May 1969
3453258 Parmerter et al. Jul 1969
3453259 Parmerter et al. Jul 1969
3464841 Skofronick Sep 1969
3479185 Chambers Nov 1969
3502476 Kohei et al. Mar 1970
3503744 Itano et al. Mar 1970
3514597 Haes et al. May 1970
3541142 Cragoe, Jr. Nov 1970
3546161 Wolheim Dec 1970
3547646 Hori et al. Dec 1970
3549367 Chang et al. Dec 1970
3553710 Lloyd et al. Jan 1971
3563931 Horiguchi Feb 1971
3565753 Yurkowitz Feb 1971
3574624 Reynolds et al. Apr 1971
3579533 Yalman May 1971
3595655 Robinson et al. Jul 1971
3595657 Robinson et al. Jul 1971
3595658 Gerlach et al. Jul 1971
3595659 Gerlach et al. Jul 1971
3607639 Krefeld et al. Sep 1971
3607693 Heine et al. Sep 1971
3607863 Dosch Sep 1971
3615562 Harrison et al. Oct 1971
3617288 Hartman et al. Nov 1971
3617335 Kumura et al. Nov 1971
3619238 Kimura et al. Nov 1971
3619239 Osada et al. Nov 1971
3637337 Pilling Jan 1972
3637581 Horioguchi et al. Jan 1972
3642472 Mayo Feb 1972
3647467 Grubb Mar 1972
3652275 Baum et al. Mar 1972
3660542 Adachi et al. May 1972
3667954 Itano et al. Jun 1972
3668188 King et al. Jun 1972
3669925 King et al. Jun 1972
3671096 Mackin Jun 1972
3671251 Houle et al. Jun 1972
3676690 McMillin et al. Jul 1972
3678044 Adams Jul 1972
3689565 Hoffmann et al. Sep 1972
3694241 Guthrie et al. Sep 1972
3695879 Laming et al. Oct 1972
3697280 Strilko Oct 1972
3705043 Zablak Dec 1972
3707371 Files Dec 1972
3729313 Smith Apr 1973
3737628 Azure Jun 1973
3765896 Fox Oct 1973
3775130 Enomoto et al. Nov 1973
3788849 Taguchi et al. Jan 1974
3799773 Watarai et al. Mar 1974
3800439 Sokolski et al. Apr 1974
3801329 Sandner et al. Apr 1974
3817752 Laridon et al. Jun 1974
3840338 Zviak et al. Oct 1974
3844790 Chang et al. Oct 1974
3870524 Watanabe et al. Mar 1975
3873500 Kato et al. Mar 1975
3876496 Lozano Apr 1975
3887450 Gilano et al. Jun 1975
3895949 Akamatsu Jul 1975
3901779 Mani Aug 1975
3910993 Avar et al. Oct 1975
3914165 Gaske Oct 1975
3914166 Rudolph et al. Oct 1975
3915824 McGinniss Oct 1975
3919323 Houlihan et al. Nov 1975
3926641 Rosen Dec 1975
3928264 Young, Jr. et al. Dec 1975
3933682 Bean Jan 1976
3952129 Matsukawa et al. Apr 1976
3960685 Sano et al. Jun 1976
3965157 Harrison Jun 1976
3978132 Houlihan et al. Aug 1976
3984248 Sturmer Oct 1976
3988154 Sturmer Oct 1976
4004998 Rosen Jan 1977
4012256 Levinos Mar 1977
4017652 Gruber Apr 1977
4022674 Rosen May 1977
4024324 Sparks May 1977
4039332 Kokelenberg et al. Aug 1977
4043819 Baumann Aug 1977
4048034 Martan Sep 1977
4054719 Cordes, III Oct 1977
4056665 Tayler et al. Nov 1977
4058400 Crivello Nov 1977
4067892 Thorne et al. Jan 1978
4071424 Dart et al. Jan 1978
4073968 Miyamoto et al. Feb 1978
4077769 Garcia Mar 1978
4079183 Green Mar 1978
4085062 Virgilio et al. Apr 1978
4090877 Streeper May 1978
4100047 McCarty Jul 1978
4105572 Gorondy Aug 1978
4107733 Schickedanz Aug 1978
4110112 Roman et al. Aug 1978
4111699 Krueger Sep 1978
4114028 Baio et al. Sep 1978
4126412 Masson et al. Nov 1978
4141807 Via Feb 1979
4144156 Kuesters et al. Mar 1979
4148658 Kondoh et al. Apr 1979
4162162 Dueber Jul 1979
4171977 Hasegawa et al. Oct 1979
4179577 Green Dec 1979
4181807 Green Jan 1980
4190671 Vanstone et al. Feb 1980
4197080 Mee Apr 1980
4199420 Photis Apr 1980
4229172 Baumann et al. Oct 1980
4232106 Iwasaki et al. Nov 1980
4238492 Majoie Dec 1980
4239843 Hara et al. Dec 1980
4239850 Kita et al. Dec 1980
4241155 Hara et al. Dec 1980
4242430 Hara et al. Dec 1980
4242431 Hara et al. Dec 1980
4245018 Hara et al. Jan 1981
4245995 Hugl et al. Jan 1981
4246330 Hara et al. Jan 1981
4248949 Hara et al. Feb 1981
4250096 Kvita et al. Feb 1981
4251622 Kimoto et al. Feb 1981
4254195 Nakamura May 1981
4256493 Yokoyama et al. Mar 1981
4256817 Hara et al. Mar 1981
4258123 Nagashima et al. Mar 1981
4258367 Mansukhani Mar 1981
4259432 Kondoh et al. Mar 1981
4262936 Miyamoto Apr 1981
4268605 Hara et al. May 1981
4268667 Anderson May 1981
4269926 Hara et al. May 1981
4270130 Houle et al. May 1981
4271252 Hara et al. Jun 1981
4271253 Hara et al. Jun 1981
4272244 Schlick Jun 1981
4276211 Singer et al. Jun 1981
4277497 Fromantin Jul 1981
4279653 Makishima et al. Jul 1981
4279982 Iwasaki et al. Jul 1981
4279985 Nonogaki et al. Jul 1981
4284485 Berner Aug 1981
4288631 Ching Sep 1981
4289844 Specht et al. Sep 1981
4290870 Kondoh et al. Sep 1981
4293458 Gruenberger et al. Oct 1981
4298679 Shinozaki et al. Nov 1981
4300123 McMillin et al. Nov 1981
4301223 Nakamura et al. Nov 1981
4302606 Barabas et al. Nov 1981
4306014 Kunikane et al. Dec 1981
4307182 Dalzell et al. Dec 1981
4308400 Felder et al. Dec 1981
4315807 Felder et al. Feb 1982
4318705 Nowak et al. Mar 1982
4318791 Felder et al. Mar 1982
4321118 Felder et al. Mar 1982
4335054 Blaser et al. Jun 1982
4335055 Blaser et al. Jun 1982
4336323 Winslow Jun 1982
4343891 Aasen et al. Aug 1982
4345011 Drexhage Aug 1982
4347111 Gehlhaus et al. Aug 1982
4349617 Kawashiri et al. Sep 1982
4350753 Shelnut et al. Sep 1982
4351893 Anderson Sep 1982
4356255 Tachikawa et al. Oct 1982
4357468 Szejtli et al. Nov 1982
4359524 Masuda et al. Nov 1982
4362806 Whitmore Dec 1982
4367072 Vogtle et al. Jan 1983
4367280 Kondo et al. Jan 1983
4369283 Altschuler Jan 1983
4370401 Winslow et al. Jan 1983
4372582 Geisler Feb 1983
4373017 Masukawa et al. Feb 1983
4373020 Winslow Feb 1983
4374984 Eichler et al. Feb 1983
4376887 Greenaway et al. Mar 1983
4383835 Preuss et al. May 1983
4390616 Sato et al. Jun 1983
4391867 Derick et al. Jul 1983
4399209 Sanders et al. Aug 1983
4400173 Beavan Aug 1983
4401470 Bridger Aug 1983
4416961 Drexhage Nov 1983
4421559 Owatari Dec 1983
4424325 Tsunoda et al. Jan 1984
4425162 Sugiyama Jan 1984
4425424 Altland et al. Jan 1984
4426153 Libby et al. Jan 1984
4434035 Eichler et al. Feb 1984
4447521 Tiers et al. May 1984
4450227 Holmes et al. May 1984
4460676 Fabel Jul 1984
4467112 Matsuura et al. Aug 1984
4475999 Via Oct 1984
4477681 Gehlhaus et al. Oct 1984
4489334 Owatari Dec 1984
4495041 Goldstein Jan 1985
4496447 Eichler et al. Jan 1985
4500355 Shimada et al. Feb 1985
4508570 Fugii et al. Apr 1985
4510392 Litt et al. Apr 1985
4523924 Lacroix Jun 1985
4524122 Weber et al. Jun 1985
4534838 Lin et al. Aug 1985
4548896 Sabongi et al. Oct 1985
4555474 Kawamura Nov 1985
4557730 Bennett et al. Dec 1985
4565769 Dueber et al. Jan 1986
4567171 Mangum Jan 1986
4571377 McGinniss et al. Feb 1986
4595745 Nakano et al. Jun 1986
4604344 Irving et al. Aug 1986
4605442 Kawashita et al. Aug 1986
4613334 Thomas et al. Sep 1986
4614723 Schmidt et al. Sep 1986
4617380 Hinson et al. Oct 1986
4620875 Shimada et al. Nov 1986
4620876 Fugii et al. Nov 1986
4622286 Sheets Nov 1986
4631085 Kawanishi et al. Dec 1986
4632891 Banks et al. Dec 1986
4632895 Patel et al. Dec 1986
4634644 Irving et al. Jan 1987
4638340 Iiyama et al. Jan 1987
4647310 Shimada et al. Mar 1987
4655783 Reinert et al. Apr 1987
4663275 West et al. May 1987
4663641 Iiyama et al. May 1987
4668533 Miller May 1987
4672041 Jain Jun 1987
4698291 Koibuchi et al. Oct 1987
4701402 Patel et al. Oct 1987
4702996 Griffing et al. Oct 1987
4704133 Reinert et al. Nov 1987
4707161 Thomas et al. Nov 1987
4707425 Sasagawa et al. Nov 1987
4707430 Ozawa et al. Nov 1987
4711668 Shimada et al. Dec 1987
4711802 Tannenbaum Dec 1987
4713113 Shimada et al. Dec 1987
4720450 Ellis Jan 1988
4721531 Wildeman et al. Jan 1988
4721734 Gehlhaus et al. Jan 1988
4724021 Martin et al. Feb 1988
4724201 Okazaki et al. Feb 1988
4725527 Robillard Feb 1988
4727824 Ducharme et al. Mar 1988
4732615 Kawashita et al. Mar 1988
4737190 Shimada et al. Apr 1988
4737438 Ito et al. Apr 1988
4740451 Kohara Apr 1988
4745042 Sasago et al. May 1988
4746735 Kruper, Jr. et al. May 1988
4752341 Rock Jun 1988
4755450 Sanders et al. Jul 1988
4761181 Suzuki Aug 1988
4766050 Jerry Aug 1988
4766055 Kawabata et al. Aug 1988
4770667 Evans et al. Sep 1988
4772291 Shibanai et al. Sep 1988
4772541 Gottschalk Sep 1988
4775386 Reinert et al. Oct 1988
4786586 Lee et al. Nov 1988
4789382 Neumann et al. Dec 1988
4790565 Steed Dec 1988
4800149 Gottschalk Jan 1989
4803008 Ciolino et al. Feb 1989
4808189 Oishi et al. Feb 1989
4812139 Brodmann Mar 1989
4812517 West Mar 1989
4813970 Kirjanov et al. Mar 1989
4822714 Sanders Apr 1989
4831068 Reinert et al. May 1989
4834771 Yamauchi et al. May 1989
4837106 Ishikawa et al. Jun 1989
4837331 Yamanishi et al. Jun 1989
4838938 Tomida et al. Jun 1989
4839269 Okazaki et al. Jun 1989
4849320 Irving et al. Jul 1989
4853037 Johnson et al. Aug 1989
4853398 Carr et al. Aug 1989
4854971 Gane et al. Aug 1989
4857438 Loerzer et al. Aug 1989
4861916 Kohler et al. Aug 1989
4865942 Gottschalk et al. Sep 1989
4874391 Reinert Oct 1989
4874899 Hoelderich et al. Oct 1989
4885395 Hoelderich Dec 1989
4886774 Doi Dec 1989
4892941 Dolphin et al. Jan 1990
4895880 Gottschalk Jan 1990
4900581 Stuke et al. Feb 1990
4902299 Anton Feb 1990
4902725 Moore Feb 1990
4902787 Freeman Feb 1990
4911732 Neumann et al. Mar 1990
4911899 Hagiwara et al. Mar 1990
4917956 Rohrbach Apr 1990
4921317 Suzuki et al. May 1990
4925770 Ichiura et al. May 1990
4925777 Inoue et al. May 1990
4926190 Lavar May 1990
4933265 Inoue et al. Jun 1990
4933948 Herkstroeter Jun 1990
4937161 Kita et al. Jun 1990
4942113 Trundle Jul 1990
4950304 Reinert et al. Aug 1990
4952478 Miyagawa et al. Aug 1990
4952680 Schmeidl Aug 1990
4954380 Kanome et al. Sep 1990
4954416 Wright et al. Sep 1990
4956254 Washizu et al. Sep 1990
4964871 Reinert et al. Oct 1990
4965294 Ohngemach et al. Oct 1990
4966607 Shinoki et al. Oct 1990
4966833 Inoue Oct 1990
4968596 Inoue et al. Nov 1990
4968813 Rule et al. Nov 1990
4985345 Hayakawa et al. Jan 1991
4987056 Imahashi et al. Jan 1991
4988561 Wason Jan 1991
4997745 Kawamura et al. Mar 1991
5001330 Koch Mar 1991
5002853 Aoai et al. Mar 1991
5002993 West et al. Mar 1991
5003142 Fuller Mar 1991
5006758 Gellert et al. Apr 1991
5013959 Kogelschatz May 1991
5017195 Satou et al. May 1991
5023129 Morganti et al. Jun 1991
5025036 Carson et al. Jun 1991
5026425 Hindagolla et al. Jun 1991
5026427 Mitchell et al. Jun 1991
5028262 Barlow, Jr. et al. Jul 1991
5028792 Mullis Jul 1991
5030243 Reinert Jul 1991
5030248 Meszaros Jul 1991
5034526 Bonham et al. Jul 1991
5037726 Kojima et al. Aug 1991
5045435 Adams et al. Sep 1991
5045573 Kohler et al. Sep 1991
5047556 Kohler et al. Sep 1991
5049777 Mechtersheimer Sep 1991
5053320 Robbillard Oct 1991
5055579 Pawlowski et al. Oct 1991
5057562 Reinert Oct 1991
5068364 Takagaki et al. Nov 1991
5069681 Bouwknegt et al. Dec 1991
5070001 Stahlhofen Dec 1991
5073448 Vieira et al. Dec 1991
5074885 Reinert Dec 1991
5076808 Hahn et al. Dec 1991
5085698 Ma et al. Feb 1992
5087550 Blum et al. Feb 1992
5089050 Vieira et al. Feb 1992
5089374 Saeva Feb 1992
5096456 Reinert et al. Mar 1992
5096489 Laver Mar 1992
5096781 Vieira et al. Mar 1992
5098477 Vieira et al. Mar 1992
5098793 Rohrbach et al. Mar 1992
5098806 Robillard Mar 1992
5106723 West et al. Apr 1992
5108505 Moffat Apr 1992
5108874 Griffing et al. Apr 1992
5110706 Yumoto et al. May 1992
5110709 Aoai et al. May 1992
5114832 Zertani et al. May 1992
5124723 Laver Jun 1992
5130227 Wade et al. Jul 1992
5133803 Moffatt Jul 1992
5135940 Belander et al. Aug 1992
5139572 Kawashima Aug 1992
5139687 Borgher, Sr. et al. Aug 1992
5141556 Matrick Aug 1992
5141797 Wheeler Aug 1992
5144964 Demain Sep 1992
5147901 Rutsch et al. Sep 1992
5153104 Rossman et al. Oct 1992
5153105 Sher et al. Oct 1992
5153166 Jain et al. Oct 1992
5160346 Fuso et al. Nov 1992
5160372 Matrick Nov 1992
5166041 Murofushi et al. Nov 1992
5169436 Matrick Dec 1992
5169438 Matrick Dec 1992
5173112 Matrick et al. Dec 1992
5176984 Hipps, Sr. et al. Jan 1993
5178420 Shelby Jan 1993
5180425 Matrick et al. Jan 1993
5180652 Yamaguchi et al. Jan 1993
5181935 Reinert et al. Jan 1993
5185236 Shiba et al. Feb 1993
5187045 Bonham et al. Feb 1993
5187049 Sher et al. Feb 1993
5190565 Berenbaum et al. Mar 1993
5190710 Kletecka Mar 1993
5190845 Hashimoto et al. Mar 1993
5193854 Borowski, Jr. et al. Mar 1993
5196295 Davis Mar 1993
5197991 Rembold Mar 1993
5198330 Martic et al. Mar 1993
5202209 Winnik et al. Apr 1993
5202210 Matsuoka et al. Apr 1993
5202211 Vercoulen Apr 1993
5202212 Shin et al. Apr 1993
5202213 Nakahara et al. Apr 1993
5202215 Kanakura et al. Apr 1993
5202221 Imai et al. Apr 1993
5205861 Matrick Apr 1993
5208136 Zanoni et al. May 1993
5209814 Felten et al. May 1993
5219703 Bugner et al. Jun 1993
5221334 Ma et al. Jun 1993
5224197 Zanoni et al. Jun 1993
5224987 Matrick Jul 1993
5226957 Wickramanayake et al. Jul 1993
5227022 Leonhardt et al. Jul 1993
5241059 Yoshinaga Aug 1993
5244476 Schulz et al. Sep 1993
5250109 Chan et al. Oct 1993
5254429 Gracia et al. Oct 1993
5256193 Winnik et al. Oct 1993
5258274 Helland et al. Nov 1993
5261953 Vieira et al. Nov 1993
5262276 Kawamura Nov 1993
5268027 Chan et al. Dec 1993
5270078 Walker et al. Dec 1993
5271764 Winnik et al. Dec 1993
5271765 Ma Dec 1993
5272201 Ma et al. Dec 1993
5275646 Marshall et al. Jan 1994
5279652 Kaufmann et al. Jan 1994
5282894 Albert et al. Feb 1994
5284734 Blum et al. Feb 1994
5286286 Winnik et al. Feb 1994
5286288 Tobias et al. Feb 1994
5294528 Furutachi Mar 1994
5296275 Goman et al. Mar 1994
5296556 Frihart Mar 1994
5298030 Burdeska et al. Mar 1994
5300403 Angelopolus et al. Apr 1994
5300654 Nakajima et al. Apr 1994
5302195 Helbrecht Apr 1994
5302197 Wickramanayke et al. Apr 1994
5310778 Shor et al. May 1994
5312713 Yokoyama et al. May 1994
5312721 Gesign May 1994
5324349 Sano et al. Jun 1994
5328504 Ohnishi Jul 1994
5330860 Grot et al. Jul 1994
5334455 Noren et al. Aug 1994
5338319 Kaschig et al. Aug 1994
5340631 Matsuzawa et al. Aug 1994
5340854 Martic et al. Aug 1994
5344483 Hinton Sep 1994
5356464 Hickman et al. Oct 1994
5362592 Murofushi et al. Nov 1994
5368689 Agnemo Nov 1994
5372387 Wajda Dec 1994
5372917 Tsuchida et al. Dec 1994
5374335 Lindgren et al. Dec 1994
5376503 Audett et al. Dec 1994
5383961 Bauer et al. Jan 1995
5384186 Trinh Jan 1995
5393580 Ma et al. Feb 1995
5401303 Stoffel et al. Mar 1995
5401562 Akao Mar 1995
5415686 Kurabayashi et al. May 1995
5415976 Ali May 1995
5424407 Tanaka et al. Jun 1995
5425978 Berneth et al. Jun 1995
5426164 Babb et al. Jun 1995
5427415 Chang Jun 1995
5429628 Trinh et al. Jul 1995
5431720 Nagai et al. Jul 1995
5432274 Luong et al. Jul 1995
5445651 Thoen et al. Aug 1995
5445842 Tanaka et al. Aug 1995
5455143 Ali Oct 1995
5459014 Nishijima et al. Oct 1995
5464472 Horn et al. Nov 1995
5466283 Kondo et al. Nov 1995
5474691 Severns Dec 1995
5475080 Gruber et al. Dec 1995
5476540 Shields et al. Dec 1995
5479949 Battard et al. Jan 1996
5489503 Toan Feb 1996
5498345 Jollenbeck et al. Mar 1996
5501774 Burke Mar 1996
5503664 Sano et al. Apr 1996
5509957 Toan et al. Apr 1996
5531821 Wu Jul 1996
5532112 Kohler et al. Jul 1996
5541633 Winnik et al. Jul 1996
5543459 Hartmann et al. Aug 1996
5571313 Mafune et al. Nov 1996
5575891 Trokhan et al. Nov 1996
5580369 Belding et al. Dec 1996
5607803 Murofushi et al. Mar 1997
5643356 Nohr et al. Jul 1997
5645964 Nohr et al. Jul 1997
5685754 Nohr et al. Nov 1997
5686503 Nohr et al. Nov 1997
5709955 Nohr et al. Jan 1998
5739175 Nohr et al. Apr 1998
5747550 Nohr et al. May 1998
5798015 Nohr et al. Aug 1998
5811199 MacDonald et al. Sep 1998
Foreign Referenced Citations (107)
Number Date Country
103085 Apr 1937 AUX
1262488 Sep 1988 AUX
413257 Oct 1932 CAX
458808 Dec 1936 CAX
460268 Oct 1949 CAX
461082 Nov 1949 CAX
463021 Feb 1950 CAX
463022 Feb 1950 CAX
465496 May 1950 CAX
465495 May 1950 CAX
465499 May 1950 CAX
483214 May 1952 CAX
517364 Oct 1955 CAX
537687 Mar 1957 CAX
552565 Feb 1958 CAX
779239 Feb 1968 CAX
930103 Jul 1973 CAX
2053094 Apr 1992 CAX
94118 May 1958 CSX
0003884 Sep 1979 EPX
0029284 May 1981 EPX
0223587 May 1987 EPX
0280458 Aug 1988 EPX
0308274 Mar 1989 EPX
0375160 Jun 1990 EPX
0373662 Jun 1990 EPX
0390439 Oct 1990 EPX
0468465 Jan 1992 EPX
0542286 May 1993 EPX
000571190 Nov 1993 EPX
0608433 Aug 1994 EPX
0639664 Feb 1995 EPX
1039835 Sep 1958 DEX
1047013 Dec 1958 DEX
1132450 Jul 1962 DEX
2437380 Feb 1975 DEX
2444520 Mar 1975 DEX
2714978 Oct 1977 DEX
3833438 Apr 1990 DEX
3833437 Apr 1990 DEX
004036328 Jul 1991 DEX
5065592 Jun 1975 JPX
5614569 Feb 1981 JPX
0014233 Feb 1981 JPX
56-36556 Apr 1981 JPX
57128283 Aug 1982 JPX
59-219270 Apr 1985 JPX
60239740 Nov 1985 JPX
60239743 Nov 1985 JPX
60239739 Nov 1985 JPX
60239741 Nov 1985 JPX
613781 Jan 1986 JPX
627703 Jan 1987 JPX
62-100557 May 1987 JPX
62127281 Jun 1987 JPX
63-43959 Feb 1988 JPX
63-223077 Sep 1988 JPX
63-223078 Sep 1988 JPX
6429337 Jan 1989 JPX
64-40948 Feb 1989 JPX
89014948 Mar 1989 JPX
1146974 Jun 1989 JPX
01210477 Aug 1989 JPX
292957 Apr 1990 JPX
2179642 Jul 1990 JPX
2282261 Nov 1990 JPX
03163566 Jul 1991 JPX
5134447 Nov 1991 JPX
3284668 Dec 1991 JPX
4023885 Jan 1992 JPX
4023884 Jan 1992 JPX
4-136075 May 1992 JPX
561220 Mar 1993 JPX
5-140498 Jun 1993 JPX
5263067 Oct 1993 JPX
6116556 Apr 1994 JPX
6116557 Apr 1994 JPX
6116555 Apr 1994 JPX
6214339 Aug 1994 JPX
6256633 Sep 1994 JPX
6256494 Sep 1994 JPX
1310767 May 1987 RUX
275245 Oct 1928 GBX
349339 May 1931 GBX
355686 Aug 1931 GBX
399753 Oct 1933 GBX
441085 Jan 1936 GBX
463515 Apr 1937 GBX
492711 Sep 1938 GBX
518612 Mar 1940 GBX
539912 Sep 1941 GBX
626727 Jul 1947 GBX
600451 Apr 1948 GBX
616362 Jan 1949 GBX
618616 Feb 1949 GBX
779389 Jul 1957 GBX
1372884 Nov 1974 GBX
2146357 Apr 1985 GBX
9211295 Jul 1992 WOX
9306597 Apr 1993 WOX
9401503 Jan 1994 WOX
9422501 Oct 1994 WOX
9422500 Oct 1994 WOX
9504955 Feb 1995 WOX
9600740 Jan 1996 WOX
9619502 Jun 1996 WOX
9622335 Jul 1996 WOX
Non-Patent Literature Citations (219)
Entry
Kubat et al. "Photophysical properties of metal complexes of meso-tetrakis (40sulphonatophenyl) porphyrin," J. Photochem. and Photobiol. 96 93-97 1996.
Abstract for WO 95/00343--A1 Textiles: Paper: Cellulose p. 7 1995.
Maki, Y. et al. "A novel heterocyclic N-oxide, pyrimido[5,4-g]pteridinetetrone 5-oxide, with multifunctional photooxidative properties" Chemical Abstracts 122 925 [no 122:31350 F] 1995.
Abstract of patent, JP 6-80915 (Canon Inc.), Mar. 22, 1994.
Abstract of patent, JP 06-43573 (Iku Meji) (Feb. 18, 1994).
Pitchumani, K. et al. "Modification of chemical reactivity upon cyclodextrin encapsulation" Chemical Abstracts 121 982 [No. 121:13362 4v] 1994.
Derwent Publications Ltd., London, JP 05297627 (Fujitsu Ltd.), Nov. 12, 1993. (Abstract).
Patent Abstracts of Japan, JP 5241369 (Bando Chem Ind Ltd et al.), Sep. 21, 1993. (Abstract).
Derwent Publications Ltd., London, JP 05232738 (Yamazaki, T.), Sep. 10, 1993. (Abstract).
Derwent Publications Ltd., London, EP 000559310 (Zeneca Ltd.), Sep. 8, 1993. (Abstract).
Derwent Publications Ltd., London, J,A, 5-230410 (Seiko Epson Corp), Sep. 7, 1993. (Abstract).
Derwent Publications Ltd., London, JP 5-230407 (Mitsubishi Kasei Corp), Sep. 7, 1993. (Abstract).
Abstract Of Patent, JP 405230410 (Seiko Epson Corp.), Sep. 7, 1993. (Abstract).
Abstract Of Patent, JP 405230407 (Mitsubishi Kasei Corp.), Sep. 7, 1993. (Abstract).
Patent Abstracts of Japan, JP 5197198 (Bando Chem Ind Ltd et al.), Aug. 6, 1993. (Abstract).
Database WPI--Derwent Publications Ltd., London, J,A, 5197069 (Bando Chem), Aug. 6, 1993. (Abstract).
Abstract of patent, JP 5-195450 (Nitto Boseki Co. Ltd), Aug. 3, 1993.
Patent Abstracts of Japan, JP5181308 (Bando Chem Ind Ltd et al.), Jul. 23, 1993. (Abstract).
Patent Abstracts of Japan, JP 5181310 (Bando Chem Ind Ltd et al.), Jul. 23, 1993. (Abstract).
Derwent Publications Ltd., London, JP 5-132638 (Mitsubishi Kasei Corp), May 28, 1993. (Abstract).
Abstract Of Patent, JP 405132638 (Mitsubishi Kasei Corp.), May 28, 1993. (Abstract).
Derwent Publications Ltd., London, JP 5-125318 (Mitsubishi Kasei Corp), May 21, 1993. (Abstract).
Abstract Of Patent, JP 405125318 (Mitsubishi Kasei Corp.), May 21, 1993. (Abstract).
Abstract of patent, JP 05-117200 (Hidefumi Hirai et al.) (May 14, 1993).
Derwent World Patents Index, JP 5117105 (Mitsui Toatsu Chem Inc.) May 14, 1993.
Derwent Publications Ltd., London, JP 05061246 (Ricoh KK), Mar. 12, 1993. (Abstract).
Husain, N. et al. "Cyclodextrins as mobile-phase additives in reversed-phase HPLC" American Laboratory 82 80-87 1993.
Hamilton, D.P. "Tired of Shredding? New Ricoh Method Tries Different Tack" Wall Street Journal B2 1993.
"Cyclodextrins: A Breakthrough for Molecular Encapsulation" American Maize Products Co. (Amaizo) 1993.
Duxbury "The Photochemistry and Photophysics of Triphenylmethane Dyes in Solid Liquid Media" Chemical Review 93 381-433 1993).
Abstract of patent, JP 04-351603 (Dec. 7, 1992).
Abstract of patent, JP 04-351602 1992.
Derwent Publications Ltd., London, JP 404314769 (Citizen Watch Co. Ltd.), Nov. 5, 1992. (Abstract).
Abstract of patent, JP 04315739 1992.
Derwent Publications Ltd., London, JP 04300395 (Funai Denki KK, Oct. 23, 1992. (Abstract).
Derwent Publications Ltd., London, JP 404213374 (Mitsubishi Kasei Corp), Aug. 4, 1992. (Abstract).
Abstract of patent, JP 04-210228 1992.
Abstract Of Patent, JP 404202571 (Canon Inc.), Jul. 23, 1992. (Abstract).
Abstract Of Patent, JP 404202271 (Mitsubishi Kasei Corp.), Jul. 23, 1992. (Abstract).
Derwent Publications Ltd., London, JP 4-189877 (Seiko Epson Corp), Jul. 8, 1992. (Abstract).
Derwent Publications Ltd., London, JP 404189876 (Seiko Epson Corp), Jul. 8, 1992. (Abstract).
Abstract Of Patent, JP 404189877 (Seiko Epson Corp.), Jul. 8, 1992. (Abstract).
Derwent Publications Ltd., London, J,A, 4-170479 (Seiko Epson Corp), Jun. 18, 1992. (Abstract).
Abstract of patent, JP 04-81402 1992.
Abstract of patent, JP 04-81401 1992.
Kogelschatz "Silent-discharge driven excimer UV sources and their applications" Applied Surface Science 410-423 1992.
Derwent Publications, Ltd., London, JP 403269167 (Japan Wool Textile KK), Nov. 29, 1991 (Abstract).
Derwent Publications Ltd., London, JO 3247676 (Canon KK), Nov. 5, 1991 (Abstract).
Abstract of patent, JP 03-220384 1991.
Patent Abstracts of Japan, JP 03184896 (Dainippon Printing Co Ltd.) Aug. 12, 1991.
Derwent Publications Ltd., London, JP 3167270 (Mitsubishi Kasei Corp), Jul. 19, 1991. (Abstract).
Derwent Publications Ltd., London, JO 3093870 (Dainippon Ink Chem KK.), Apr. 18, 1991 (Abstract).
Abstract of patent, JP 06369890 1991.
Kogelschatz, U. et al. "New Excimer UV Sources for Industrial Applications" ABB Review 1-10 1991.
Abstract of patent, JP 03-41165 1991.
"Coloring/Decoloring Agent for Tonor Use Developed" Japan Chemical Week 1991.
Braithwaite, M., et al. "Formulation" Chemistry & Technology of UV & EB Formulation for Coatings, Inks & Paints IV 11-12 1991.
Scientific Polymer Products, Inc. Brochure 24-31 1991.
Dietliker, K. "Photoiniators for Free Radical and Catioinc Polymerisation" Chem & Tech of UV & EB Formulation for Coatings, Inks & Paints III 280 1991.
Esrom et al. "Large area Photochemical Dry Etching of Polymers iwth Inocoherent Excimer UV Radiation" MRS Materials Research Society 1-7 1991.
"New Excimer UV Sources for Industrial Applications" ABB Review 391 1-10 1991.
Esrom et al. Excimer Laser-Induced Decomposition of Aluminum Nitride Materials Research Society Fall Meeting 1-6 1991.
Esrom et al. "Metal deposition with a windowless VUV excimer source" Applied Surface Science 1-5 1991.
Esrom "Excimer Laser-Induced Surface Activation of Aln for Electroless Metal Deposition" Mat. Res. Sco.lSymp. Proc. 204 457-465 1991.
Zhang et al. "UV-induced decompositin of adsorbed Cu-acetylacetonate films at room temperature for electroless metal plating" Applied Surface Science 1-6 1991.
"German company develops reuseable paper" Pulp & Paper 1991.
Abstract of patent, JP 02289652 1990.
Ohashi et al. "Molecular Mechanics Studies on Inclusion Compounds of Cyanine Dye Monomers and Dimers in Cyclodextrin Cavities," J. Am. Chem. Soc. 112 5824-5830 1990.
Kogelschatz et al. "New Incoherent Ultraviolet Excimer Sources for Photolytic Material Deposition," Laser Und Optoelektronik 1990.
Patent Abstracts of Japan, JP 02141287 (Dainippon Printing Co Ltd.) May 30, 1990.
Abstract of Patent, JP 0297957, (Fuji Xerox Co., Ltd.) 1990.
Derwent Publications Ltd., London, JP 2091166 (Canon KK), Mar. 30, 1990. (Abstract).
Esrom et al. "Metal Deposition with Incoherent Excimer Radiation" Mat. Res. Soc. Symp. Proc. 158 189-198 1990.
Esrom "UV Excimer Laer-Induced Deposition of Palladium from palladiym Acetate Films" Mat. Res. Soc. Symp. Proc. 158 109-117 1990.
Kogelschatz, U. "Silent Discharges for the Generation of ultraviolet and vacuum ultraviolet excimer radiation" Pure & Applied Chem. 62 1667-74 1990.
Esrom et al. "Investigation of the mechanism of the UV-induced palladium depositions processf from thin solid palladium acetate films" Applied Surface Science 46 158-162 1990.
Zhang et al. "VUV synchrotron radiation processing of thin palladium acetate spin-on films for metallic surface patterning" Applied Surface Science 46 153-157 1990.
Brennan et al. "Tereoelectronic effects in ring closure reactions: the 2'-hydroxychalcone--flavanone equilibrium, and related systems," Canadian J. Chem. 68 (10) pp. 1780-1785 1990.
Abstract of patent, JP 01-299083 1989.
Derwent Publications Ltd., London, J,O, 1182379 (Canon KK), Jul. 20, 1989. (Abstract).
Derwent Publications Ltd., London, JO 1011171 (Mitsubishi Chem Ind. KK.), Jan. 13, 1989 (Abstract).
Gruber, R.J., et al. "Xerographic Materials" Encyclopedia of Polymer Science and Engineering 17 918-943 1989.
Pappas, S.P. "Photocrosslinking" Comph. Pol. Sci. 6 135-148 1989.
Pappas, S.P. "Photoinitiated Polymerization" Comph. Pol. Sci. 4 337-355 1989.
Kirilenko, G.V. et al. "An analog of the vesicular process with amplitude modulation of the incident light beam" Chemical Abstracts 111 569 [No. 111:12363 3b] 1989.
Esrom et al. "UV excimer laser-induced pre-nucleation of surfaces followed by electroless metallization" Chemtronics 4 216-223 1989.
Esrom et al. "VUV light-induced deposition of palladium using an incoherent Xe2* excimer source" Chemtronics 4 1989.
Esrom et al. "UV Light-Induced Deposition of Copper Films" C5-719-C5-725 1989.
Falbe et al. Rompp Chemie Lexikon 9 270 1989.
Derwent Publications, Ltd., London, SU 1423656 (Kherson Ind Inst), Sep. 15, 1988 (Abstract).
Derwent Publications, Ltd., London, EP 0280653 (Ciba Geigy AG), Aug. 31, 1988 (Abstract).
Abstract of patent, JP 63-190815 1988.
Patent Abstracts of Japan, JP 63179985 (Tomoegawa Paper Co. Ltd.), Jul. 23, 1988.
Derwent World Patents Index, JP 63179977 (Tomoegawa Paper Mfg Co Ltd), Jul. 23, 1988.
Furcone, S.Y. et al. "Spin-on B14Sr3Ca3Cu4O16+= superconducting thin films from citrate precursors," Appl. Phys. Lett. 52(25) 2180-2182 1988.
Abstract of patent, JP 63-144329 1988.
Abstract of patent, JP 63-130164 1988.
Derwent Publications, Ltd., London, J6 3112770 (Toray Ind Inc), May 17, 1988 (Abstract).
Derwent Publications, Ltd., London, J6 3108074 (Konishiroku Photo KK), May 12, 1988 (Abstract).
Derwent Publications, Ltd., London, J6 3108073 (Konishiroku Photo KK), May 12, 1988 (Abstract).
Abstract of patent, JP 61-77846 1988.
Abstract of patent, JP 63-73241 1988.
Abstract of patent, JP 6347762, 1988.
Abstract of patent, JP 63-47763, 1988.
Abstract of patent, JP 63-47764, 1988.
Abstract of patent, JP 63-47765, 1988.
Eliasson, B., et al. "UV Excimer Radiation from Dielectric-Barrier Discharges" Applied Physics B 46 299-303 1988.
Eliasson et al. "New Trends in High Intensity UV Generation" EPA Newsletter (32) 29-40 1988.
Cotton, F.A. "Oxygen: Group Via(16)" Advanced Inorganic Chemistry 5th ed. 473-474 1988.
Derwent Publications, Ltd., London, J6 2270665 (Konishiroku Photo KK), Nov. 25, 1987 (Abstract).
Abstract of patent, JP 62-215261 1987.
Database WPI, Derwent Publications Ltd., London, JP 62032082 (Mitsubishi Denki KK), Feb. 12, 1987, (Abstract).
Abstract of patent, JP 62-32082 1987.
Derwent Publications Ltd., London, J6 2007772 (Alps Electric KK.), Jan. 14, 1987 (Abstract).
Gross et al. "Laser direct-write metallization in thin palladium acetate films" J. App. Phys. 61 (4) 1628-1632 1987.
Al-Ismail et al. "Some experimental results on thin polypropylene films loaded with finely-dispersed copper" Journal of Materials Science 415-418 1987.
Baufay et al. "Optical self-regulation during laser-induced oxidation of copper" J. Appl. Phys 61 (9) 4640-4651 1987.
Derwent Publications Ltd., London, JA 0284478 (Sanyo Chem Ind Ltd.), Dec. 15, 1986 (Abstract).
Abstract of patent, JP 61251842 1986.
Database WPI, Derwent Publications Ltd., London, GB; SU, A, 1098210 (Kutulya L A) Jun. 23, 1986.
Abstract of patent, JP 61-97025 1986.
Abstract of patent, JP 61-87760 1986.
Derwent Publications Ltd., London, DL 0234731 (Karl Marx Univ. Leipzig), Apr. 9, 1986 (Abstract).
Derwent World Patents Index, SU 1219612 (AS USSR Non-AQ Soln) Mar. 23, 1986.
Derwent Publications, Ltd., London, J6 1041381 (Osaka Prefecture), Feb. 27, 1986 (Abstract).
Dialog, JAPIO, JP 61-034057 (Ciba Geigy AG) Feb. 18, 1986.
Derwent World Patents Index, JP 61027288 (Sumitomo Chem Ind KK) Feb. 6, 1986.
Sakai et al. "A Novel and Practical Synthetic Method of 3(2H)-Furanone Derivatives," J. Heterocyclie Chem. 23 pp. 1199-1201 1986.
Jellinek, H.H.G. et al. "Evolution of H2O and CO2 During the Copper-Catalyzed Oxidation of Isotactic Polypropylene," J. Polymer Sci. 24 389-403 1986.
Jellinek, H.H.G. et al. "Diffusion of Ca2+ Catalysts from Cu-Metal Polymer or Cu-Oxide/Polymer Interfaces into Isotactic Polypropylene," J. Polymer Sci. 24 503-510 1986.
John J. Eisch and Ramiro Sanchez "Selective, Oxophilic Imination of Ketones with Bis (dichloroaluminum) Phenylimide" J. Org. Chem. 51 (10) 1848-1852 1986.
Derwent Publications Ltd., London, J6 0226575 (Sumitomo Chem Ind Ltd.), Oct. 11, 1986 (Abstract).
Abstract of patent, Jp 60-156761 1985.
Derwent Publications Ltd., London, J,A, 0011451 (Fugi Photo Film KK), Jan. 21, 1985. (Abstract).
Derwent Publications Ltd., London J6 0011-449-A (Taoka Chemical KK) Jan. 21, 1985 (abstract).
Roos, G. et al. "Textile applications of photocrosslinkable polymers" Chemical Abstracts 103 57 [No. 103:23690j] 1985.
Derwent World Patents Index, EP 127574 (Ciba Geigy AG), Dec. 5, 1984.
Derwent Publications Ltd., London, JP 0198187 (Canon KK), Nov. 9, 1984. (Abstract).
Derwent Publications Ltd., London, J,A, 0169883 (Ricoh KK), Sep. 25, 1984. (Abstract).
Derwent Publications Ltd., London, JA 0198187 (Canon KK), Sep. 11, 1984 (Abstract).
Derwent Publications Ltd., London, J.A. 0053563 (Dainippon Toryo KK), Mar. 28, 1984. (Abstract).
Derwent Publications Ltd., London, J,A, 0053562 (Dainippon Toryo KK), Mar. 28, 1984. (Abstract).
Derwent Publications Ltd., London, J,A, 0051961 (Dainippon Toryo KK), Mar. 26, 1984. (Abstract).
Abstract of Patent, JA 0051961 (Dainippon Toryo KK), Mar. 26, 1984 (Abstract).
Saenger, W. "Structural Aspects of Cyclodextrins and Their Inclusion Complexes" Inclusion Compounds--Structural Aspects of Inclusion Compounds formed by Organic Host 2 231-259 1984.
Szejtli "Industrial Applications of Cyclodextrins" Inclusion Compounds Physical Prop. & Applns. 3 331-390 1984.
Kano et al. "Three-Component Complexes of Cyclodextrins. Exciplex Formation in Cyclodextrin Cavity," J. Inclusion Phenomena 2 pp. 737-746 1984.
Suzuki et al. "Spectroscopic Investigation of Cyclodextrin Monomers, Derivatives, Polymers and Azo Dyes," J. Inclusion Phenomena 2, pp. 715-724 1984.
Abstract of patent, JA 0222164 (Ricoh KK), Dec. 23, 1983 (Abstract).
Abstract of patent, JP 58211426 (Sekisui Plastics KK), (Dec. 8, 1983).
Derwent Publications, Ltd., London, EP 0072775 (Ciba Geigy AG), Feb. 23, 1983 (Abstract).
van Beek, H.C.A "Light-Induced Colour Changes in Dyes and Materials" Color. Res. and Appl. 8 176-181 1983.
Connors, K.A. "Application of a stoichiometric model of cyclodextrin complex formation" Chemical Abstracts 98 598 [No. 98:53067g] 1983.
Abstract of Patent, EP 0065617 (IBM Corp.), Dec. 1, 1982 (Abstract).
Derwent Publications Ltd., London, J,A, 0187289 (Honshu Paper Mfg KK), Nov. 17, 1982. (Abstract).
Abstract of Patent, JA 0187289 (Honsho Paper Mfg KK), Nov. 17, 1982. (Abstract).
Abstract of Patent, JA 0185364 (Ricoh KK), Nov. 15, 1982 (Abstract).
Derwent Publications, Ltd., London J5 7139-146 (Showa Kako KK) Aug. 27, 1982(abstract).
Abstract of Patent, JA 0090069 (Canon KK), Jun. 4, 1982 (Abstract).
Derwent Publications, Ltd., London, JA 0061785 (Nippon Senka KK), Apr. 14, 1982 (Abstract).
Fischer, "Submicrosopic contact imaging with visible light by energy transfer" Appl. Phys. Letter 40(3) 1982.
Abstract of Patent, JA 0010659 (Canon KK), Jan. 2, 1982 (Abstract).
Abstract of Patent, JA 0010661 (Canon KK), Jan. 2, 1982 (Abstract),
Christen "Carbonylverbindungen: Aldehyde und Ketone," Grundlagen der Organischen Chemie 255 1982.
Derwent Publications Ltd., London, J,A, 0155263 (Canon KK), Dec. 1, 1981. (Abstract).
Abstract of Patent, JA 0155263 (Canon KK), Dec. 1, 1981 (Abstract).
Abstract of Patent, JA 0147861 (Canon KK), Nov. 17, 1981 (Abstract).
Derwent Publications Ltd., London, J,A, 0143273 (Canon KK), Nov. 7, 1981. (Abstract).
Abstract of Patent, JA 0143272 (Canon KK), Nov. 7, 1981 (Abstract).
Abstract of Patent, JA 0136861 (Canon KK), Oct. 26, 1981 (Abstract).
Abstract of Patent, JA 6133378 (Canon KK), Oct. 19, 1981 (Abstract).
Abstract of Patent, JA 6133377 (Canon KK), Oct. 19, 1981 (Abstract).
Abstract of Patent, JA 6093775 (Canon KK), Jul. 29, 1981 (Abstract).
Derwent Publications Ltd., London, J,A, 0008135 (Ricoh KK), Jan. 27, 1981. (Abstract).
Derwent Publications Ltd., London, J,A, 0004488 (Canon KK), Jan. 17, 1981. (Abstract).
Abstract of Patent, JA 0004488 (Canon KK), Jan. 17, 1981 (Abstract).
Kirk-Othmer "Metallic Coatings," Encyclopedia of Chemical Technology 15 241-274 1981.
Komiyama et al. "One-Pot Preparation of 4-Hydroxychalcone .beta.-Cyclodextrin as Catalyst," Makromol. Chem. 2 733-734 1981.
Derwent Publications, Ltd., London CA 1086-719 (Sherwood Medical) Sep. 30, 1980 (abstract).
Rosanske et al. "Stoichiometric Model of Cyclodextrin Complex Formation" Journal of Pharmaceutical Sciences 69 564-567 (5) 1980.
Semple et al. "Synthesis of Functionalized Tetrahydrofurans," Tetrahedron Letters 81 pp. 4561-4564 1980.
Kirk-Othmer "Film Deposition Techniques," Encyclopedia of Chemical Technology 10 247:283 1980.
Derwent World Patents Index, Derwent Info. Ltd., JP 54158941 (Toyo Pulp KK), Dec. 15, 1979. (Abstract).
Derwent World Patents Index, JP 54117536 (Kawashima F) Sep. 12, 1979.
Derwent Publications Ltd., London, J,A, 0005422 (Fuji Photo Film KK), Jan. 16, 1979. (Abstract).
Drexhage et al. "Photo-bleachable dyes and processes" Research Disclosure 85-87 1979.
"Color imaging devices and color filter arrays using photo-bleachable dyes" Research Disclosure 22-23 1979.
Wolff, N.E., et al. "Electrophotography" Kirk-Othmer-Encyclopedia of Chemical Technology 8 794-826 1979.
Derwent Publications Ltd., London, J,A, 0012037 (Pentel KK), Jan. 29, 1977. (Abstract).
Abstract of Patent, JA 0012037 (Pentel KK), Jan. 29, 1977 (Abstract).
Jenkins P.W. et al. "Photobleachable dye material" Research Disclosure 18 [No. 12932] 1975.
Lamberts, R.L. "Recording color grid patterns with lenticules" Research Disclosure 18-19 [No. 12923] 1975.
Karmanova, L.S. et al. "Light stabilizers of daytime fluorescent paints" Chemical Abstracts 82 147 [No. 59971p] 1975.
Prokopovich, B. et al. "Selection of effective photoinducers for rapid hardening of polyester varnish PE-250" Chemical Abstracts 83 131 [no 81334a] 1975.
"Variable Contrast Printing System" Research Disclosure 19 [No. 12931] 1975.
Lakshman "Electronic Absorption Spectrum of Copper Formate Tetrahydrate" Chemical Physics Letters 31 (2) 331-334 1975.
Derwent Publications, Ltd., London J4 9131-226 (TNational Cash Register C) Dec. 16, 1974 (abstract).
Chang, I.F., et al. "Color Modulated Dye Ink Jet Printer" IBM Technical Disclosure Bulletin 17(5) 1520-1521 1974.
"Darocur 1173: Liquid Photoiniator for Ultraviolet Curing of Coatings" 1974.
Hosokawa et al. "Ascofuranone, an antibiotic from Ascochyta," Japan Kokai 73 91,278 (Nov. 28, 1973) Merck Index 80 p. 283; abstract 94259t 1974.
Abstract of patent, NL 7112489 (Dec. 27, 1971).
Gafney et al. "Photochemical Reactions of Copper (II)--1,3-Diketonate Complexes" Journal of the Americqal Chemical Society 1971.
Derwent Publications, Ltd., London SU 292698-S Jan. 15, 1971 (abstract).
Derwent World Patent Index,CS 120380 (Kocourek, Jan) Oct. 15, 1966.
Rigdon, J.E. "In Search of Paper that Spies Can't Copy" Wall Street Journal.
Chatterjee, S. et al. "Photochemistry of Carbocynanine Alkyltriphenylborate Salts: Intra-Ion-Pair Electron Transfer and the Chemistry of Boranyl Radicals" J. Am. Chem. Soc. 112 6329-6338.
"Assay--Physical and Chemical Analysis of Complexes" Amaizo.
"Cyclodextrin" Amaizon.
"Beta Cyclodextrin Polymer (BCDP)" Amaizo.
"Chemically Modified Cyclodextrins" Amaizo.
"Cyclodextrin Complexation" American Maize Products Co.
"Monomers" Scientific Polymer-Products Inc.
Suppan, Paul "Quenching of Excited States" Chemistry and Light 65-69.
Yamaguchi, H. et al. "Supersensitization, Aromatic ketones as supersensitizers" Chemical Abstracts 53 107 (d).
Stecher, H. "Ultraviolet-absorptive additives in adhesives, lacquers and plastics" Chemical Abstracts 53 14579 (c).
Maslennikov, A.S. "Coupling of diazonium salts with ketones" Chemical Abstracts 60 3128e.
Derwent Publications Ltd., London, 4 9128022.
Abstract of Patent, JP 405195450.
Rose, Philip I. "Gelatin," Encyclopedia of Chemical Technology 7 488-513.
Continuations (1)
Number Date Country
Parent 625737 Mar 1996
Continuation in Parts (4)
Number Date Country
Parent 537593 Oct 1995
Parent 463188 Jun 1995
Parent 327077 Oct 1994
Parent 268685 Jun 1994