Patent Application
20070017042
The present invention is directed to an indicator system(s) and methods of using same.
A colorimetric indicator system including a reactive material that has a first state that is substantially unreactive to the presence of oxygen and a second state that is substantially reactive to the presence of oxygen. The first state includes at least one blocked dye derived by the reduction of a dye selected from azines, oxazines, thiazines, and combinations thereof; and said second state comprises said at least one blocked dye unblocked, where the blocked dye is derived by the reduction of a dye having the formula (I):
wherein Y represents O, S, or NR12, wherein R12 is selected from hydrogen, alkyl, or aryl groups; Z is selected form NR9 R10, OR11, hydrogen, alkyl, aryl, azo, or fused aromatic components: R1, R2, R3, R4, R5, and R6 each independently is selected from hydrogen, alkyl or aryl groups; and X— represents a halogen or other suitable anion. The colorimetric indicator of the present invention is affixed to an/or integral with at least one of a package wall, a packaged object, an identification badge, and a substrate. Where substrate is inclusive of anything that holds or serves as a foundation, base, point of attachment, backing, back, or support for the reactive material.
A colorimetric indicator system including a reactive material that has a first state that is substantially unreactive to the presence of oxygen and a second state that is substantially reactive to the presence of oxygen. The first state includes at least one blocked dye derived by the reduction of a dye having the formula III, and combinations thereof; and said second state comprises said at least one blocked dye unblocked, where the blocked dye is derived by the reduction of a dye having the formula (III):
wherein R1-R4, R7 each independently is selected from hydrogen, alkyl, aryl, alkoxy, halogens, hydroxyl, CN, substituted thiols, SO2 alkyl, SO2 aryl, CO2 alkyl, or CO2 aryl, where alkyl and aryl can be substituted and may include atoms necessary to complete an aromatic or acyclic ring system, which may contain heteroatoms and substitution; R5, R6 each independently is selected from hydrogen, alkyl, aryl, alkoxy, where alkyl and aryl can be substituted and may include atoms necessary to complete an aromatic or acyclic ring system. The colorimetric indicator of the present invention is affixed to and/or integral with at least one of a package wall, a packaged object, an identification badge, and a substrate. Where substrate is inclusive of anything that holds or serves as a foundation, base, point of attachment, backing, back, or support for the reactive material.
An advantage of the disclosed indicator system(s) and applications is that the indicator system(s) can be applied to a package and/or good and/or service and/or item in a blocked form i.e., substantially unreactive to a triggering stimulus. For example, the indicator system(s) may be printed on a substrate in the presence of its triggering stimulus and not undergo is observable change until unblocked. The blocking group also imparts characteristics that greatly enhance the solubility of the indicators in organic solvents and monomers/polymers thus increasing their ease of application.
It is contemplated that the various embodiments and elements described herein can be used in combination. All manner of attaching the indicator system are contemplated by the present invention. Moreover, it is contemplated that the indicator system can have any shape or size.
Persons skilled in the art will recognize that there may be different devices, mechanism, and methods of operation that are within the spirit and scope of the invention herein disclosed. Also, it should be understood that the drawings, while useful for illustrating the invention, are not intended to be necessarily to scale. To the extent that drawings imply dimensions and relative size positions, the drawings should be regarded as illustrative only and not limiting the invention to particular dimensions, sizes, positions, and location of parts.
The below disclosure employs the term substrate to describe a number of disclosed embodiments. Substrate means any surface and/or boundary, where internal and/or external and/or interstitial, for which the indicator system is and/or can be placed and/or affixed and/or otherwise attached. A substrate may be rigid, flexible, transparent, opaque, linear, curved, flat, elliptical and/or combinations thereof. For example, substrate includes, for example, the surface or at least a portion thereof of a good and/or service and/or item and/or package. Moreover, the use of substrate in the present disclosure encompasses systems in which the indicator system is integral and/or sandwiched between two layers of materials, such as, for example, a film.
Package Integrity
One embodiment consistent with the present invention is directed to a system for determining whether the anaerobic seal on a package and/or device has been compromised and its contents exposed to air. This embodiment may be used in conjunction with packages used in the good, pharmaceutical and medicinal industries and others which can be compromised by tampering or exposure to the atmosphere or which may deteriorate due to the presence of oxygen. This embodiment permits evaluation of such oxygen sensitive materials without liberating them from a package. For example, a cardiac stent after being manufactured and packaged under sterile conditions has to be shipped to a hospital or other like facility where it will be applied to a patient. It is useful to the physicians performing the procedures that they can ascertain the sterility of the stent and associated package and whether the integrity of the package was breached from the time it was sent from the manufacturing facility to the facility where the procedure is to be performed. The present embodiment is directed to a package system, wherein the package includes an indicator system. The indicator system is initially in a first state. For example, the first sate is a substantially transparent state. The indicator system transforms to a second state upon the happening of a triggering event and/or after a predetermined period of time. For example, the second state is a colored state and/or substantially non-transparent state. If the package is compromised and/or otherwise fails, the indicator system transitions from a first state to a second state wherein the transition and resultant second state is detectable and/or observable. The indicator system can be applied to the package in a number of ways, all of which are readily available and known in the art. For example, the indicator system can be printed, i.e., via an ink jet printer, contact print, spot application, or any number of application methods, on one of the layers and/or surfaces that make up the internal boundary of the package; adhered to one of the layers and/or surfaces that make up the internal boundary of the package; and/or integral to the packaging material itself.
Times Out Applications
A further and overlapping embodiment consistent with the present invention is directed to a system for timing out the validity and/or usefulness of a product and/or device and/or item. The applications of this embodiment are legion. For example, visitors to a building an/or document facility are typically given an access badge and/or pass. These badges and/or passes are typically provided for a predefined period of time, thus they have a limited useful life, i.e., a one day pass to a library archive. The badges and/or passes are printed, at least in part, with the indicator system. The indicator system has a first state and a second state. After a predetermined time the indicator system transitions from its first state to its second state. The transition can be from one color to another and/or colored to clear and/or clear to colored. Alternatively, the indicator systems spell out a word and/or phrase on the badge and/or pass. The word and/or phrase is initially substantially clear. After a predefined time the word an/or phrase becomes visibly observable. At such time the badge and/or pass is not longer valid. A further example includes, a document that includes and offer that expires after a day or price quotes that are only valid for a week. The offer that is to expire and/or the price quotes are printed using the indicator system of the present invention. The indicator system has a first state and a second state. After a predetermined time the indicator system transitions from its first state to its second state. The transition can be form one color to another and/or colored to clear and/or clear to colored.
Shelf Life
A yet further and overlapping embodiment of the present invention is directed to a system for determining the potability and/or consumability and/or shelf life of food. For example, fresh meats and vegetables have a finite life span in which they need to be prepared and consumed before they spoil. All spoilage is not detectable by the eye. In some instances food that has spoiled is consumed and results in sickness and/or illness and in some instances death. To increase the shelf life of food there have been great development strides in packaging materials, including films and preformed trays and anaerobic packaging. However, since packaged foods are transported to their retail destinations and handled a number of times in stock there exists a danger that the package might become compromised, thereby shortening the intended shelf life of the food. Alternatively, a retailer may not be entirely honest or with no malice intended, leave the food item out beyond its shelf life. In the above situations it would be beneficial to consumers if there was yet another layer of protection. The present invention provides an indicator system for conveying the potability and/or consumability and/or shelf life of food. For example, the indicator system is a dot that transitions from a first state to a second state. The first state is substantially transparent. The second state is substantially opaque and/or colored so as to be detectable by the consumer. The transition occurs after exposure to a predefined stimulus, such as for example oxygen, and/or after a predefined period of time. Alternatively, the indicator system may take the form of a word and/or phrase. The word and/or phrase being initially substantially transparent and transitioning to a substantially opaque and/or colored state. The indicator system can take many different configurations, including for example, an indicator dye in communication with a scavenger material. After the scavenger material is exhausted the indicator dye transitions from its first state to a second state, thereby providing a predefined shelf life for a packaged product. Alternatively, the indicator system operates independently of a scavenger material. The indicator system can be applied to the package in a number of ways, all of which are readily available and known in the art. For example, the indicator system can be printed, i.e., via an ink jet printer, contact print, spot application, or any number of application methods, on one of the layers and/or surfaces that make up the internal boundary of the package; adhered to one of the layers and/or surfaces that make up the internal boundary of the package; and/or integral to the packaging material itself.
Cellular and/or Biotechnology Assays, Tests, and/or Diagnostics
In another embodiment of the present invention, the indicator system can be used to monitor redox activity in cells and tissues. Since reactive oxygen species are produced only by live cells the indicators can also provide a means for determining cell viability. The indicator system has a first state and a second state and transitions from its first state to its second state following enzymatic activity and interaction with reactive oxygen species. The transition can be from one color to another and/or colored to clear and/or clear to colored. The transition can also be from fluorescent to non-fluorescent or non-fluorescent to fluorescent.
Archive Material Monitoring System
A further and overlapping embodiment of the present embodiment is directed to an indicator system for the preservation of works of art and/or other oxygen sensitive works from antiquities. Certain types of artistic media are sensitive to oxygen and/or readily oxidizable. This sensitivity can cause colors to fade. To this end certain works of art and/or documents from antiquity are stored and/or preserved in oxygen free and/or climate controlled environments. The indicator system of the present embodiment allows the environments to be monitored for changes. The indicator system of the present embodiment has a first state and a second state. Upon environmental changes of a deleterious nature the indicator system transitions from a first state to a second state. The transition is observable.
Security Application
Another and overlapping embodiment of the present invention is directed to a security system for a packaged good and/or service and/or document. An indicator system is affixed to the packaged good and/or service and/or document. A barrier layer and/or package prevents access to the good and/or service and/or document. Once the barrier layer and/or package is compromised the indicator system transitions from a first state to a second state. The transition is observable. The indicator system can be affixed and/or integrated with the good and/or service and/or document such that it can not be removed without damaging the good and/or service and/or document. The indicator system provides a system for the indication of whether tampering and/or access and/or unauthorized access has occurred. The indicator system can be applied to the good and/or service and/or document in a number of ways, all of which are readily available and known in the art. For example, the indicator system can be printed, i.e., via an ink jet printer, contact print, spot application, or any number of application methods, on one of the layers and/or surfaces that make up the good and/or service and/or document; adhered to one of the layers and/or surfaces that make up the good and/or service and/or document; and/or integral to the good and/or service and/or document. The indicator system provides a way for determining whether an item has been tampered with and/or whether it was accessed outside proper protocol.
Medical Application
Another and overlapping embodiment of the present invention is directed to an indicator system for determining whether an item has been exposed to a sterilization oxidant. In this embodiment the indicator system is attached and/or affixed and/or in communication with the item. After the item is exposed to a sterilization oxidant the indicator transitions from a first state to a second state. The transition is observable and/or detectable.
Barcode Application
Yet another overlapping embodiment consistent with the present invention includes the use of the indicator system in conjunction with one or more barcodes. The barcodes may, for example, be those associated with a retail product—such as a consumable good or for tracking a package or an identification pass and/or badge. The indicator system is placed in communication with a least one barcode. After a predefined period of time or predetermined event the indicator system acts to prevent the barcode from being read by a barcode scanner and/or reader. For example, the indicator system may be placed in communication with a barcode under which a perishable item is packaged—for example meat. After a predetermined time and as determined by the shelf life of the good the indicator system transitions to a state that prevents the barcode from being read and thus indicating to a cashier or barcode scanner operator that the good is not longer sellable and/or good.
Indicator Materials
In one embodiment of the present invention, the stimulus triggering the reaction is exposure to atmospheric oxygen. Upon exposure to oxygen, a reactive material, e.g., leuco methylene blue, which is essentially colorless, is oxidized to form an opaque or semi-opaque state (e.g., the deep blue dye, methylene blue). By adjusting the time it takes to turn opaque, this method can be used to provide the contemplated applications.
Possible reactive materials include, but are not limited to, oxygen sensitive leuco or reduced forms of phenothiazines, phenoxazines, and phenazinies, whose members include: Methylene Blue, Brilliant Cresyl Blue, Basic Blue 3, Methylene Green, Taylor's Blue, Meldola's Blue, New Methylene Blue, Thionin, Nile Blue, Celestine Blue, and Toluidine 0, as well as reaction products and combinations comprising at least one of the foregoing material; the structures of which are set forth below:
A method for the synthesis of leucomethylene blue and the oxygen dependent reoxidation to form the colored form of the methylene blue dye is illustrated below and be found in more detail in U.S. Pat. No. 7,026,029, herein after incorporated by reference in its entirety.
In addition to the above reactive materials, numerous dyes can be synthesized to operate in accordance with the above disclosed applications. For example, some other possible reactive materials can be found in U.S. Pat. No. 4,404,257, hereafter incorporated by reference, and U.S. Pat. No. 5,815,484, hereafter incorporated by reference; both in their entirety. Additional examples include.
(a) leuco-azine dyes., such as those disclosed in U.S. Pat. No. 4,710,570, herein incorporated by reference in its entirety.
in which:
X is O, S, NR2
Z completes a fused aromatic or hetercyclic ring system
N is 0 or 1 to allow one R1 ring substituent
Q represents CR4R5 in which at least one of R4 and R5 is an electronegative group or R4 and R5 may complete a ring, or when X is S, Q may represent NR3 in which R3 is an aromatic or heterocyclic group.
(b) quinoneimines, including indamines, indophenols, and indoanilines, such as those disclosed in U.S. Pat. No. 5,424,475, herein incorporated by reference in its entirety and for example, include the following:
where X, Y, and Z can be but are not limited to: hydrogen, alkyl, alkoxy, aryl, substituted alkyl, alkoxy, and aryl, OH, CN, halogens, NR6R7, SR8R9 where R2-R9 may be hydrogen alkyl, aryl, substituted alkyl or aryl, or may represent the atoms necessary to complete an aromatic or acyclic ring system which may contain heteroatoms and substitution.
(c) anthraquinones; and include, for example,
where R1 and R2 can be but are not limited to: hydrogen, alkyl, alkoxy, aryl, substituted alkyl, alkoxy, and aryl, OH, CN, halogens, NR5R6, SR7, SO2R8 where R5-R8 may be hydrogen, alkyl, aryl, substituted alkyl or aryl, or may represent the atoms necessary to complete an aromatic or acyclic ring system which may contain heteroatoms and substitution.
(d) acridinies; and include, for example,
where R1-R4 call be but are not limited to: hydrogen, alkyl, aryl, substituted alkyl or aryl, or may represent the atoms necessary to complete an aromatic or acyclic ring system which may contain heteroatoms with substitution, and R5 can be but is not limited to: hydrogen, alkyl, aryl, substituted alkyl and aryl groups.
(e) and di- and triarylmethane dyes, such as those disclosed in U.S. Pat. No. 5,330,864 and herein incorporated by reference in its entirety and include for example,
where X and Y can be but are not limited to: hydrogen, alkyl, alkoxy, aryl, substituted alkyl, alkoxy and aryl, OH, CN, halogens, NR6R7, SR8, SO2R9 where R2-R7 may be hydrogen alkyl, aryl, substituted alkyl or aryl, or may represent the atoms necessary to complete all aromatic or acyclic ring system which may contain heteroatoms and substitution. It is understood that R1 can be a substituted aryl.
Additional reactive materials include, but are not limited to, pH indicator materials, materials that undergo photopolymerization, materials that produce precipitates, and light activated chemistries.
By using reactive materials that absorb at different wavelengths it is possible to prepare indicators of varying color. These indicators may be combined to produce a mixed indicator that can be used as a timing agent for the above disclosed applications. The individual indicators in a mix can respond to the same trigger but at different time intervals or they can respond to different triggers at different time intervals changing from a first state to a second state. For example, the first state is a substantially transparent state. The indicator system transforms to a second state upon the happening of a triggering event and/or after a predetermined period of time. For example, the second state is a colored state and/or substantially non-transparent state. As an example, the following aminonaphthoquinones absorbs in the blue region of the visible spectrum.
wherein
R1-R4, R7 each independently is selected from hydrogen, alkyl, aryl, alkoxy, halogens, hydroxyl, CN, substituted thiols, SO2 alkyl, SO2 aryl, CO2 alkyl, or CO2 aryl, where alkyl and aryl can be substituted an may include atoms necessary to complete an aromatic or acyclic ring system, which may contain heteroatoms and substitution;
R5, R6 each independently is selected from hydrogen, alkyl, aryl, alkoxy, where alkyl and aryl can be substituted and may include atoms necessary to complete an aromatic or acyclic ring system.
The synthesis of these type compounds as well as other classes of dyes that absorb in this region can be found in pending U.S. application Ser. Nod. 11/273,804 filed on Nov. 14, 2005; 11/273,805 filed on Nov. 14, 2005; 11/274,392 filed on Nov. 14, 2005; 11/274,550 filed on Nov. 14, 2005; 11/274,743 filed on Nov. 14, 2005; and 11/274,865 filed on Nov. 14, 2005 all of which are herein incorporated by reference in their entirety.
The reactive materials can further comprise a mixture comprising at least one of any of the above mentioned reactive materials.
In one embodiment of the present invention, the reactive material is mixed with a carrier for deposition on and/or impregnation into at least a portion of the surface of the substrate. Possible carriers comprise the thermoplastic acrylic polymers, polyester resins, epoxy resins, polythiolenes, UV curable organic resins, polyurethanes, thermosettable acrylic polymers, alkyds, vinyl resins and the like, as well as combinations comprising at least one of the foregoing carriers. Polyesters include, for example the reaction products of aliphatic dicarboxylic acids including, e.g., fumaric or maleic acid with glycols, such as ethyleneglycol, propyleneglycol, neopentylglycol, and the like, as well as reaction products and mixtures comprising at least one of the foregoing.
Some epoxy resins, which can be used as the organic resin, include monomeric, dimeric, oligomeric, or polymeric epoxy material containing one or a plurality of epoxy functional groups. For example, reaction products of bis phenol-A and epichlorohydrin, or the epichlorohydrin with phenol-formaldehyde resins, and the like. Other organic resins can be in the form of mixtures of polyolefin and polythiols, such as shown by Kehr et al, U.S. Pat. No. 3,697,395 and U.S. Pat. No. 3,697,402, hereafter incorporated by reference.
Optionally, the reactive layer and/or material can be applied to the substrate using various coating techniques such as painting, dipping, spraying, spin coating, screen printing, ink jet printing, and the like. For example, the reactive layer and/or material can be mixed with a relatively volatile solvent, preferably an organic solvent, which is capable of dissolving the carrier. Examples of some suitable organic solvents include ethylene glycol diacetate, butoxyethanol, the lower alkanols, and the like.
For surface coatings, the reactive layer and/or material may also optionally contain various additives such as flatting agents, surface active agents, thixotropic agents, and the like, and reaction products and combinations comprising at least one of the foregoing additives. The thickness of the reactive layer and/or material is dependent upon the particular reactive material employed, the concentration thereof in the reactive layer and/or material, and the desired absorption characteristics of the layer both initially and after a desired period of time.
Development of Blocked Reactive Compounds
One embodiment of the present invention is the use of blocked forms of the reactive compounds in the reactive layer and/or material. These compounds will unblock within a predetermined time period after the good and/or service and/or item is manufactured and/or packaged and/or printed, and typically before the good an/or service and/or item is used by the consumer. This is desirable when the stimulus that triggers the reaction can trigger this reaction during the manufacturing of the good and/or service and/or item, and thus measures need to be taken so that the reactive compound is not activated during the manufacturing of the good and/or service and/or item. For example, in the case of oxygen triggered reactions, unless a blocked form of the reactive compound is used, manufacturing may need to take place in an oxygen free environment, such as a nitrogen atmosphere.
One embodiment of the present invention comprises the use of a chemically blocked an/or modified and/or protected reactive substance(s). Specific exemplary blocked dyes and methods of preparing dye precursors are disclosed. Leuco dye precursors, which permit the deblocking, and oxidation of the leuco dye precursors at acceptable rates and methods of applying dyes and dye precursors to a good and/or service and/or items both on the surface of the good and/or service and/or items and/or package surface are. disclosed herein and in U.S. Pat. No. 7,026,029, herein incorporated by reference in its entirety. Also disclosed is the use of bases to increase the rate of methylene blue generation in blocked leuco dye-containing layers in or an optical good and/or service and/or items.
All of the problems discussed in the previous two paragraphs could be avoided if the leuco dye could be coated in a solventless, light or radiation cured (hereafter called generically “UV-cured”) layer and/or area. The major obstacle to creating such a system is that many leuco dyes, and in particular leucomethylene blue (hereafter “LMB”), inhibit both radical and cationic polymerization reactions of the type used to cure UV-curable monomers such as the acrylates. The oxidized dyes (including methylene blue) also are inhibitors of such polymerization reactions. So putting a leuco dye (which will contain some of the oxidized, colored dye) in a UV-curable composition will either prevent the UV-curing from taking place, or slow the UV-curing and make the process much less economical. Moreover, the process of UV-curing can result in some of the leuco-dye becoming oxidized if any oxygen and/or other oxidizing agent is present in the layer to be cured, resulting in a produce prematurely containing oxidized dye.
Blocked versions of leucomethylene blue are known and have been used in such applications, and one such compound at least, benzoyl-leucomethylene blue (BLMB), is commercially available. However, it has been found that BLMB does not deblock easily enough to yield an acceptable good and/or service and/or item. Other blocked leucomethylene blue compounds share this problem or deblock too easily such that oxidizable leucomethylene blue is generated in the coating fluid before it is desired.
It has been found that triisopropylsilyloxycarbonylleucomethylene blue (hereafter “TIPSOCLMB”), whose structure and exemplary synthesis are disclosed in U.S. Pat. No. 7,026,029, herein incorporated by reference in its entirety, has the following desirable properties.
1. It is readily synthesized in two steps from commercially available staring materials. By isolating and purifying the BOC-LMB produced in the first step the TIPSOCLMB is prepared from a pure compound rather than from the typically very impure methylene blue.
2. It can be incorporated into an acrylate formulation described in Example 1 in which it is stable in its original blocked form for up to a year at temperatures below 0 degree C, allowing coating formulations to be prepared at one facility and shipped to another facility, if desired.
3. It can be deblocked in a period of a week or less, presumably by a hydrolysis reaction involving water or other nucleophiles which can either be provided in the acrylate formulation or be absorbed from the atmosphere in which the good and/or service and/or item is manufactured or in the packaging material. Nucleophiles that have shown utility for deblocking are fluoride ion and carboxylate ion, both of which can deblock under essentially neutral pH conditions.
4. The deblocked LMB is stable (to oxidation to methylene blue) in the absence of oxygen. The rate at which the deblocked LMB oxidizes in the presence of oxygen can be controlled by regulating the effective pH of the coating formulation. It is known in the art that the rate of oxidation of LMB increases as the pH of its environment increases. Thus the rate of oxidation can be increased by the addition of basic substances that are soluble in the matrix containing deblocked or blocked LMB and which do not react with the matrix or substrate used. One such basic compound is DABCO (1,4-diazabicyclo[2.2.2]octane), an amine. Other amines may be added or substituted. Further, the addition of a strong protic acid such as, for example, camphorsulfonic acid decreases the rate of LMB oxidation in a polymer film.
5. In the absence of water or other nucleophiles, it is a stable solid which can be stored after synthesis for at least several months, even in the presence of oxygen. Acrylate-based coating fluids containing TIPSOCLMB can be handled in the presence of oxygen until the deblocking reaction has taken place, this reaction is slow enough that the handling of the coating fluid during the manufacturing processes can be done in normal (undried) air and is not difficult.
Formulation of Surface Coating Fluid Containing TIPSOCLMB
80 mg TIPSOCLMB80 mg Irgacure 819 (Ciba Geigy; sensitizer) 4.0 ml CD-501 acrylate (Sartomer; propoxylated [6] trimethylopropanetriacrylate) 18.5 mg 1,4-diazabicycle[2.2.2]octane (“Dabco”, Aldrich; base) 155 mul 1,1,1,3,3,3-hexamethyldisilazane (““HMDZ”; Aldrich”; stabilizer)
The TIPSOCLMB, Irgacure 819, and Dabco are weighed into a brown glass bottle, a stir bar is added, the CD-501 is poured in to the proper weight, and the HMDZ is added by syringe. Dry nitrogen is blown into the bottle for a few minutes and the bottle is capped and the cap covered by parafilm. The contents are stirred at room temperature for at least two hours to dissolve the solids. If not all of the material is used, blow the bottle with nitrogen, cap and seal with parafilm, and store in a freezer; warm the bottle before opening to prevent water from condensing in the bottle.
Preparation of Disk Surface-Coated with TIPSOCLMB/Acrylate Formulation
A substrate is centered on a laboratory spin coating turntable rotating at roughly 60 rpm's. A 4 ml solution from example #5 is then applied uniformly in a circular ring by a syringe at about a 34 to 40 mm diameter from the center of the substrate an/or good and/or service and/or item. The spin speed is then rapidly increased to about 200 rpm for about 15 seconds, resulting in a coating of acrylate/TIPSOCLMB fluid about five .mu.m thick. The spinning is slowed; excess fluid wiped off the edge with a tissue and base solvent, if available, and then removed to a lab bench. At this point, the good and/or service and/or item and/or substrate is subjected to about five flashes from a Norlite 400 xenon flash lamp at its max setting. The time between flashes is dictated by the charging of the flash lamp, but should be sufficient as to not induce added stress from heat generated in the cure (typically about 5 seconds). This process will yield a clear, uncolored, fully cured acrylate film. Other substrates were also prepared with similar acrylate formulations that contain either no Dabco or 10 times the amount of Dabco described in Example 1.
The TIPSOCLMB formulations from Example 1, which was used to provide a surface layer on the surface of a DVD disc in Example 2, may also be utilized for surface coatings on a wide variety of materials and goods by any known surface coating technique such as roll, slot, flow, dip, curtain, spray, and rod coatings followed by UV curing to render the coating into the colorless solid state. In particular, an ink jet spray technique could be used to print a colorless image, text message, or barcode, such as “Expired” or “Do Not Use” on the package or goods that would, after oxidation of the colorless LMB to the colored MB, provide a clear indication of the status of the goods stored within the package.
Such UV cured surface coatings prepared with alkoxylated monomers have shown poor photostability: increasing levels of Sartomer monomers SR502 (ethoxylated-9 trimethylol triacrylate) and CD501 (propoxylated-6 trimethylol triacrylate) result in increasingly poor photostability of TIPSOC-LBM derived methylene blue even in the presence of added photostabilizers and as such these coatings may not be adequate for badge security type uses. Photostability as a coating within a light tight bottle, package or good will be adequate for tamper proof or anaerobic seal monitors.
Oxygen and redox indicating surface coatings that do not require UV curing, may be formulated by dissolving TIPSOCLMB, an appropriate deblocking catalyst, and a reducing agent timing additive if needed, into a suitable volatile inert solvent based polymer solution. Any of the coating methods mentioned above may be used to control the coating thickness and the surface coating is rendered into the colorless solid state by volatilization of the solvent. Suitable volatile inert solvents include, but are not limited to, acetone, MEK, acetonitrile, methylene chloride, dichloroethane, aliphatic and aromatic hydrocarbons. Solvents and additives that are more aggressive to initiating the deblocking reaction of TIPSOCLMB may be incorporated by utilizing in-line mixing techniques that are well known to those skilled in the art. Likewise, for longer term solution stability, polymer materials must be selected from those would be inert for initiating the deblocking reaction of TIPSOCLMB; such polymer materials would include acrylate polymers such as polymethylmethacrylate and its higher homologues and copolymers, aliphatic polymers such as TOPAS, polyesters, vinyl resins, and mixtures thereof. A wider selection of polymer materials that may increase the rate of deblocking of TIPSOCLMB may be incorporated into the coating by utilizing in-line mixing techniques that are well known to those skilled in the art. Such polymer materials for in-line blend applications may include virtually all known functional groups, including, but not limited to carboxylic acid, sulfonic acid, amine, and hydroxyl groups.
Formulation of Sandwich Coating Fluid Containing TIPSOCLMB
This example incorporates the use of a photostabilizer (polyhydroxystyrene) to prevent photobleaching of the oxidized indicating label or marking. Excessive photobleaching of the methylene blue chromophore in a strong light source would result in a negative indication of exposure to oxygen even though such exposure had occurred and thus lead to defeat of the indicating marker or time limiting mechanism of a timed badge.
This example also incorporates the use of a reducing agent which results in an increase in time before the expired signal is generated. Stannous ethylhexanoate has been found to be effective when used at a weight percent level of 0-10%, with a preferred level of 0-5%. Higher levels tend to cause coating defects in the present formulation, but higher levels may become more usable with formulation variations knowledgeable to those skilled in the art.
Part A was prepared by first combining the Sartomer monomers SR440, SR495and SR231 (Sartomer Company, 502 Thomas Jones Way, Exton, Pa. 19341), followed by the dissolution of the polyhydroxystyrene (PHS-8EO1; Triquest, L. P., 14785 Preston Road, Dallas, Tex. 75254-9123) with stirring and slight warming to 60° C. With continued stirring, the Tinuvin 292 (Ciba Specialty Chemcals, 540 White Plains Road, Tarrytown, N.Y. 10591-9005) was then added, followed by the Irgacure 819 (Ciba Specialty Chemcals, 540 White Plains Road, Tarrytown, N.Y. 10591-9005). The mixture was stirred in the dark until homogeneous. Part A is very stable and may be stored in the dark at about room temperature for several months before use. Part B was prepared by dissolving TIPSOC-LMB in Sartomer SR339 under a nitrogen atmosphere with slight warming to 50° C. Part C comprises a single component and then requires no treatment other than weighing.
The full active adhesive was then prepared by the addition of Part C into Part B followed by vigorous mixing at room temperature, and then adding this mixture into Part A followed by vigorous mixing at room temperature. The adhesive was used within four hours of mixing by spreading or applying the fluid mixture between two substrates, one of which must be of sufficient optical transmission to allow curing with a typical UV light source used for such purposes. The fluid mixture application processes include spin coating of small objects, such as has been previously described for DVD discs, and various lamination techniques, as are known to those skilled in the art, for the manufacture of roll or sheet goods.
The advantage of laminated structures is the added ability to further control timing of the indicator system by restricting the diffusion of oxygen to the laminating adhesive that now contains LMB after deblocking. The oxygen permeability of each side of the laminated structure may be varied over a wide range by those skilled in the art.
A substrate is centered data side up on the turntable as stated above. The turntable is held stationary while the fluid is dispensed on the substrate in a manner creating drops with a syringe roughly 3.about.5 mm. These are evenly spaced about 3 mm apart on a The substrate to be bonded is then placed facing the diameter of 30.about.40 mm. The substrate to be bonded is then placed facing the solution and slightly bowed away from the bottom substrate by the edges. The substrate will be lowered at angle until the first contact point between a fluid drop and top substrate occurs. To avoid air bubble and entrapped air and subsequent bubbles the substrate is rotated in a clockwise rotation while keeping it slightly bent under light pressure until each of the fluid drops begins to form a capillary bridge ring. Once the capillary ring is completed, the top substrate is released and the capillary action will continue. We can wait for the capillary flow to cover the surface, or we can spin the substrate at 100 rpm's. At this point the turntable can be turned on and rotated at about 500 rpm's for 5 seconds. The substrate can then be wiped and then be UV cured. At this point, the substrate is subjected to about 20 about 30 flashes from a Norlite 400 xenon flash lamp at it max setting. The time between flashes is dictated by the charging of the flash lamp, but should be sufficient as to not induce added stress from heat generated in the cure (typically 5 seconds). This process will yield a clear, uncolored, fully cured acrylate film. Other substrates are prepared with similar acrylate formulations that contain either no Dabco or 10 times the amount of Dabco described in Example 1.
Controlling the Timing of the Reaction
One benefit of this embodiment of the present invention is that for a broad class of stimuli, such as those requiring diffusion of a substance through a barrier layer, incorporating the reactive material in sandwich and/or between two substrates results in substantial advantages regarding the timing characteristics of the reaction.
One method of achieving the above mentioned desirable timing characteristics is to use a reactive material between two substrate materials, which reacts with a substance that needs to diffuse through the substrates. For example, if the reactive material is sensitive to oxygen, there will be an extended period in which there will be no reaction while the oxygen diffuses through at least one substrate. Once oxygen reaches the reactive material, the resulting reaction can be fast, resulting in rapid change in the reactive material.
When oxygen is used as the diffusing substance, it may be necessary to remove oxygen that dissolves in the good and/or service and/or item and/or package during the different stages of its manufacture. This can be done, for example, by storing the good and/or service and/or items in a vacuum or in an oxygen free environment for an appropriate period of time. It has been established theoretically and experimentally that 24 hours is an adequate period to extricate oxygen dissolved in a 0.6 mm thick polycarbonate substrate. Alternatively, if a blocked reactive material is used as described earlier, all oxygen scavenging material, such as iron or an organometallic compound, can be used to extricate oxygen from the optical good and/or service and/or item and/or package before the blocked reactive material unblocks. This method has several manufacturing advantages; for example, it can avoid oxygen extrication during manufacturing of the good and/or service and/or item and/or package by including the oxygen scavenging material in the packaging of the good and/or service and/or item, which allows the extrication of the oxygen to take place after the good and/or service and/or item is manufactured and packaged.
Another means for controlling the timing of the expiration of the good and/or service and/or item is to include in or adjacent to the reactive material a finite, controlled quantity of an appropriate protective substance, such as all antioxidant in the case that the reactive material reacts with oxygen. The protective substance would prevent the reactions that cause the good and/or service and/or item and/or package to change indicator state until such time as the anti-oxidant was consumed, at which time the good and/or service and/or item and/or package indicator would rapidly degrade. For example, an organometallic compound that reacts with oxygen can be packaged with the good and/or service and/or item to protect the good and/or service and/or item from oxidation while in the package. Alternatively, the organometallic compound can be incorporated into the substrate, thus continuing to protect the metal layer for a period of time alter the package has been opened.
Depletion of a protective substance could be combined with diffusion of the triggering substance through a substrate of the good and/or service and/or item and/or package, to result in longer delays before the good and/or service and/or item expires, or to enable finer control of the characteristics of the expiration process.
Alternatively, the protective substance may be a reducing agent that may be incorporated into the reactive bonding material itself. Alternate reducing agents might include other Sn (II) compounds which would be soluble in the UV cure formulation, such as acetylacetonate chelates, fatty alpha-aminoacid chelates and salts; soluble iron (II) compounds, such as fatty carboxylates and chelates such as acetylacetonates; ascorbic acid and its derivatives such as ascorbyl palmitrate; hydroquinones, such as 2,5-di-tert-amylhydroquinone; alkylhydroxylamines; hydrazines; dithionates with a solubilizing counterion; reducing saccharides such as glucose; alpha-hydroxyketones, such as acetol; appropriately substituted boron and silicon hydrides. Although many of these materials are difficultly soluble in current active adhesive formulations, a more expeditious choice of monomers and oligimers might allow the use of one of these alternate reducing agents while still providing good adhesive and dye stabilization properties.
Preventing Photobleaching of Expired Good and/or Service and/or Items
Polyhydroxystyrenes (for example, PHS-XE-01, available from ChemFirst Electronic Materials L. P, 14785 Preston Road, Suite 480, Dallas, Tex. 75254-912), have been found to be effective photostabilizers for azine dyes in UV cured adhesives. Enhanced photostabilization of azine dyes occurs in formulations in which the selected monomer mixture has a more hydrophobic character. The hydrophobic character may be characterized in this system by alcohol group content; low levels of alcohol groups result in a more hydrophobic matrix compared to higher levels of alcohol. In one experiment, the ratio of monomers (Sartomer SR395, isodecyl acrylate; Sartomer SR495, caprolactone acrylate; and Sartomer SR349, ethoxylated bisphenol A diacrylate) was varied such that the weight % of SR495 (hydroxy containing monomer) ranged from 39% to 62%. Improved photostability of the methylene blue (produced via in-situ deblocking and oxidation of TIPSOC-LMB) in the respective cured bonding adhesives was found in the formulation with the lower alcohol content.
An additional benefit of a polymeric light stabilizer is that a higher concentration of photostabilizer may be incorporated into the adhesive mixture with the upper limit to be found only as a result of high viscosity. Usable adhesives with concentrations of PHS as high as 35% by wt have been formulated; conventional monomeric phenolic organic compounds tend to form crystals which have been found to limit their solubility and thus their utility in active adhesive formulations.
A polymeric phenol made by the acid catalyzed addition of hydroxyphenyl carbinol, known as PHS-B available from ChemFirst Electronic Materials L. P, has been also been found to be very effective as a photostabilizer in these systems. Copolymers of 4-hydroxystyrene such as with styrene and butyl acrylate also show photostabilization effects in bonding resins; many copolymers would be expected to be effective here.
The photostability of azine dyes other than methylene blue is also improved with the addition of polyhydroxystyrene polymers.
Additionally, photostability can be improved by adding resorcinol derivatives such as 4-hexylresorcinol or 4-cholorresorcinol. Photostability may be further improved by increasing the TIPSOC concentration to the good and/or service and/or item.
Accordingly, the present invention has been described at some degree of particularity directed to the exemplary embodiments of the present invention. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the exemplary embodiments of the present invention without departing from the inventive concepts contained herein.
Equivalents
As will be apparent to those skilled in the art to which the invention pertains, the present invention may be embodied in forms other than those specifically disclosed above without departing from the spirit or essential characteristics of the invention. The particular embodiments of the invention described above are, therefore, to be considered as illustrative and not restrictive. The scope of the invention is as set forth in the appended claims rather than being limited to the examples contained in the foregoing description.
This application claims priority under 35 U.S.C. 120 and is a continuation-in-part of U.S. patent application Ser. No. 11/273,805, filed Nov. 14, 2005, which claims priority to and is a continuation of U.S. patent application Ser. No. 10/651,627, filed Aug. 29, 2003, now U.S. Pat. No. 7,026,029, which claimed priority under 35 U.S.C. 119 to U.S. Provisional Patent Application No. 60/415,480, filed Oct. 2, 2002, and is a continuation-in-part of U.S. patent application Ser. No. 10/163/473, filed Jun. 5, 2002, which claimed priority to U.S. Provisional Patent Application No. 60/295,903, filed Jun. 5, 2001, all of which are incorporated by reference herein in their entirety. This application also claims priority under 35 U.S.C. 120 and is a continuation-in-part of U.S. patent application Ser. Nos. 11/273,804; 11/274,392; 11/274,550; 11/274,743; and 11/274,865, all of which were filed on Nov. 14, 2005, and all of which claim priority under 35 U.S.C. 119 to U.S. Provisional Patent Application No. 60/627,787, filed Nov. 12, 2004; U.S. Provisional Patent Application No. 60/627,638, filed Nov. 12, 2004; U.S. Provisional Patent Application No. 60/627,209, filed Nov. 12, 2004; U.S. Provisional Patent Application No. 60/627,386, filed Nov. 12, 2004; and U.S. Provisional Patent Application No. 60/711,616, filed Aug. 26, 2005, all of which are hereby incorporated by reference as if set forth herein in their entirety. This application also claims priority under 35 U.S.C. 119 to U.S. Provisional Patent Application No. 60/672,610, filed Apr. 19, 2005, the disclosure of which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60415480 | Oct 2002 | US | |
| 60295903 | Jun 2001 | US | |
| 60627787 | Nov 2004 | US | |
| 60627638 | Nov 2004 | US | |
| 60627209 | Nov 2004 | US | |
| 60627386 | Nov 2004 | US | |
| 60711616 | Aug 2005 | US | |
| 60672610 | Apr 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11273805 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 10651627 | Aug 2003 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 10163473 | Jun 2002 | US |
| Child | 11379254 | Apr 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11273804 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 11274392 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 11274550 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 11274743 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
| Parent | 11274865 | Nov 2005 | US |
| Child | 11379254 | Apr 2006 | US |
