Thermally-responsive record material

Abstract

An improved thermally-responsive record material having improved image retention is disclosed. The invention is an improved thermally-responsive record member, typically a sheet material, bearing a thermally-responsive color-forming composition comprising a chromogenic material, an acidic developer material, and a metal salt of a compound of the formula ##STR1## wherein M is a metal selected from Zn, Ca, Sn, Ni, Cu, Al, Co, and Mg; wherein m corresponds to the valency of M;wherein n is 1 to 3;wherein R.sup.1 is selected from hydrogen, halogen, alkyl, oxyalkyl, or NO.sub.2, with the proviso that the alkyl group is of 1 to 50 carbons;wherein R.sup.2 is selected from hydrogen, alkyl, or aryl, with the proviso that the alkyl group is of 1-5 carbon; anda suitable binder therefor.

Description

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to thermally-responsive record material. It more particularly relates to such record material in the form of sheets coated with color-forming systems comprising chromogenic material and acidic color developer material. This invention particularly concerns a thermally-responsive record material capable of forming a non-reversible image resistant to fade or erasure. The invention teaches a record material having improved image retention density.

2. Description of Related Art

Thermally-responsive record material systems are well known in the art and are described in many patents, for example, U.S. Pat. Nos. 3,539,375; 3,674,535; 3,746,675; 4,151,748; 4,181,771; 4,246,318; and 4,470,057 which are incorporated herein by reference. In these systems, basic chromogenic material and acidic color developer material are contained in a coating on a substrate which, when heated to a suitable temperature, melts or softens to permit said materials to react, thereby producing a colored mark.

Thermally-responsive record materials have characteristic thermal responses, desirably producing a colored image of sufficient intensity upon selective thermal exposure.

A drawback of thermally-responsive record materials limiting utilization in certain environments and applications has been the undesirable tendency of thermally-responsive record materials upon forming an image to not retain that image in its original integrity over time when the thermally-responsive record material is handled or exposed to common liquids or oils or plasticizers such as found in skin oil, plastic food wrap, cooking oil and common carbonless paper solvents. As a result, a high degree of care and control in handling imaged thermally-responsive record materials has been required. This loss of image density and fade can be not only annoying but potentially damaging commercially whenever the integrity of records is allowed to become suspect through improper record storage.

The ability of a thermally-responsive record matrial to resist image fading or erausure upon contact with common oils, solvents or plasticizers would be an advance in the art and of commercial significance.

It is an object of the present invention to disclose a thermally-responsive record material having improved image retention and resistance to fade or erasure. The record material of the invention is remarkably resistant to fade or erasure when contacted with common oils, such as skin oil, internal phase or carbonless solvents, or plasticizers.

It is an object of the present invention to disclose a thermally-responsive recording material having an improved thermal response.

It is an object of the present invention to disclose a thermally-responsive record mateial comprising a support member bearing a thermally-sensitive color forming composition comprising chromogenic material and acidic developer material in contiguous relationship, whereby the melting or sublimation of either material produces a change in color by reaction between the two, a metal salt of a cinnamic acid, and a suitable binder therefor.

SUMMARY OF THE INVENTION

The present invention is a novel thermally-responsive record material bearing a thermally-sensitive color-forming composition comprising a chromogenic material and an acidic developer material in contiguous relationship, whereby the melting or sublimation of either material produces a change in color by reaction between the two, a metal salt of a cinnamic acid of the formula ##STR2## wherein M is a metal selected from Zn, Ca, Sn, Ni, Cu, Al, Co and Mg, most preferably M is Zn or Ca;

wherein m corresponds to the valency of M; wherein n is 1 to 3; wherein R.sup.1 is selected from hydrogen, halogen, alkyl, oxyalkyl, NO.sub.2, wherein R.sup.2 is selected from hydrogen, alkyl, or aromatic group, with the proviso that the R.sup.1 and R.sup.2 alkyl groups individually are of 1-5 carbons. Preferably, R.sup.1 is selected from hydrogen, chlorine, CH.sub.3, OCH.sub.3, and NO.sub.2. Preferably n is 1. A suitable binder for the above is also included.

More preferably the present invention is a novel thermally-responsive record material bearing a thermally-sensitive color-forming composition comprising a chromogenic material and an acidic developer material in contiguous relationship, whereby the melting or sublimation of either material produces a change in color by reaction between the two, a metal salt of a cinnamic acid of the formula ##STR3## wherein M is a metal selected from Zn, Ca, Sn, Ni, Cu, Co and Mg, most preferably M is Zn or Ca;

wherein R.sup.1 is selected from hydrogen, halogen, alkyl, oxyalkyl, NO.sub.2, wherein R.sup.2 is selected from hydrogen, alkyl, or aromatic group, with the proviso that the R.sup.1 and R.sup.2 alkyl groups individually are of 1-5 carbons. Preferably, R.sup.1 is selected from hydrogen, chlorine, CH.sub.3, OCH.sub.3, and NO.sub.2. A suitable binder for the above is also included.

The metal can also be aluminum, it being understood it typically has a valence of 3, thus three cinnamic groups can associate to such.

The thermally-responsive record material of the invention has the unexpected and remarkable properties of being capable of forming a non-reversible high density image upon selective thermal contact and of retaining that image over time when handled or exposed to common skin oils, internal phase or carbonless solvents, and plasticizers. This remarkable ability of the metal salts of cinnamic acids to impart fade and erasure resistance to thermally-responsive record materials is a significant advance in the art.

DETAILED DESCRIPTION

Description of Preferred Embodiments

The present invention is a novel thermally-responsive record material bearing a thermally-sensitive color-forming composition comprising a chromogenic material and an acidic developer material in contiguous relationship, whereby the melting or sublimation of either material produces a change in color by reaction between the two, a metal salt of a cinnamic acid of the formula ##STR4## wherein M is a metal selected from Zn, Ca, Sn, Ni, Cu, Co, and Mg, preferably M is Zn or Ca.

wherein m corresponds to the valency of M; wherein n is 1 to 3; wherein R.sup.1 is selected from hydrogen, halogen, alkyl, oxyalkyl, NO.sub.2, with the proviso that the alkyl or oxyalkyl groups are each of 1-5 carbons, preferably, R.sup.1 is selected from hydrogen, Cl, CH.sub.3, OCH.sub.3, and NO.sub.2. R.sup.2 is selected from hydrogen, alkyl or an aromatic group, with the proviso that the alkyl group is of 1-5 carbons. A suitable binder for the above is also included.

Most preferred among the metallic salts of the cinnamic acids and cinnamic acid derivatives are di(3-phenyl-2-propenoate)zinc more commonly referred to as zinc (cinnamate).sub.2 or zinc cinnamate; zinc (2-chlorocinnamate).sub.2 ; zinc(3-chlorocinnamate).sub.2 ; zinc(4-chlorocinnamate).sub.2 ; zinc(2-methoxycinnamate).sub.2 ; zinc(3-methoxycinnamate).sub.2 ; zinc(4-methoxycinnamate).sub.2 ; zinc (3,4,5-trimethoxycinnamate).sub.2 ; zinc(4-methylcinnamate).sub.2 ; zinc(2-nitrocinnamate).sub.2 ; and zinc(3-nitrocinnamate).sub.2.

More than three substituents on the phenyl ring (i.e. n being 4 or 5) can be utilized but such compositions are less suitable for commercial record materials.

The metallic salts of cinnamic acid and its derivatives can be readily prepared either by dissolving the corresponding sodium salt in water, or, by dissolving the corresponding cinnamic acid or derivative in solvent, adding the metal salt such as zinc salt, followed by mild heating. The organometallic product is precipated from the solution.

The invention comprises a thermally-sensitive color-forming composition comprising chromogenic material and acidic developer material, a metal salt of a cinnamic acid of formula I and binder material. The unexpected feature of this composition is that, the inclusion of the above metal salt of cinnamic acid of formula I with prior art thermally-sensitive color-forming compositions results in a composition possessing improved resistance to fade and image erasure.

The record material according to the invention has a non-reversible image in that it is non-reversible under the action of heat. The coating of the record material of the invention is basically a dewatered solid at ambient temperature and differs from reversible solvent liquid based compositions such as taught by Kito et al., in U.S. Pat. Nos. 4,720,301 and 4,732,810 which erase upon exposure to elevated temperature from 20.degree. C. to 50.degree. C. The image herein formed is non-reversible at such temperature.

Isomeric form was found not to diminish image retentiveness. In most cases the trans isomer was preferable. However, no case was identified wherein the cis isomer did not function effectively, thus the isomeric form did not appear itself determinative of effectiveness. While the trans form of the geometric isomer was somewhat preferred, nonetheless similarities in chemical properties of these diastereomers are encountered.

The color-forming composition (or system) of the record material of this invention comprises chromogenic material in its substantially colorless state and acidic developer material such as, for example, phenolic compounds. The metal salt of a cinnamic acid can itself be the developer material though this is not preferred. The color-forming system relies upon melting, softening, or subliming one or more of the components to achieve reactive, color-producing contact.

The record material includes a substrate or support material which is generally in sheet form. For purposes of this invention, sheets can be referred to as support members and are understood to also mean webs, ribbons, tapes, belts, films, cards and the like. Sheets denote articles having two large surface dimensions and a comparatively small thickness dimension. The substrate or support material can be opaque, transparent or translucent and could, itself, be colored or not. The material can be fibrous including, for example, paper and filamentous synthetic materials. It can be a film including, for example, cellophane and synthetic polymeric sheets cast, extruded, or otherwise formed. The gist of this invention resides in the color-forming composition coated on the substrate. The kind or type of substrate material is not critical.

The components of the color-forming system are in a contiguous relationship, substantially homogeneously distributed throughout the coated layer material deposited on the substrate. In manufacturing the record material, a coating composition is prepared which includes a fine dispersion of the components of the color-forming system, polymeric binder material, surface active agents and other additives in an aqueous coating medium. The composition can additionally contain inert pigments, such as clay, talc, aluminum hyroxide, calcined kaolin clay and calcium carbonate; synthetic pigments, such as urea-formaldehyde resin pigments; natural waxes such as Carnuba wax; synthetic waxes; lubricants such as zinc stearate; wetting agents; defoamers, sensitizers and antioxidants. Sensitizers, for example, can include acetoacet-o-toluidine, phenyl-1-hydroxy-2-naphthoate, 1,2-diphenoxyethane, and p-benzylbiphenyl.

The color-forming system components are substantially insoluble in the dispersion vehicle (preferably water) and are ground to an individual average particle size of between about 1 micron to about 10 microns, preferably about 1-3 microns. The polymeric binder material is substantially vehicle soluble although latexes are also eligible in some instances. Preferred water soluble binders include polyvinyl alcohol, hydroxy ethylcellulose, methylcellulose, methyl-hydroxypropylcellulose, starch, modified starches, gelatin and the like. Eligible latex materials include polyacrylates, styrene-butadiene-rubber latexes, polyvinylacetates, polystyrene, and the like. The polymeric binder is used to protect the coated materials from brushing and handling forces occasioned by storage and use of thermal sheets. Binder should be present in an amount to afford such protection and in an amount less than will interfere with achieving reactive contact between color-forming reactive materials.

Coating weights can effectively be about 3 to about 9 grams per square meter (gsm) and preferably about 5 to about 6 gsm. The practical amount of color-forming materials is controlled by economic considerations, functional parameters and desired handling characteristics of the coated sheets.

Eligible chromogenic compounds, such as the phthalide, leucauramine and fluoran compounds, for use in the color-forming system are well known color-forming compounds. Examples of the compounds include Crystal Violet Lactone (3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide, U.S. Pat. No. Re. 23,024); phenyl-, indol-, pyrrol-, and carbazol-substituted phthalides (for example, in U.S. Pat. Nos. 3,491,111; 3,491,112; 3,491,116; 3,509,174); nitro-, amino-, amido-, sulfon amido-, aminobenzylidene-, halo-, anilino-substituted fluorans (for example, in U.S. Pat. Nos. 3,624,107; 3,627,787; 3,641,011; 3,642,828; 3,681,390); spirodipyrans (U.S. Pat. No. 3,971,808); and pyridine and pyrazine compounds (for example, in U.S. Pat. Nos. 3,775,424 and 3,853,869). Other specifically eligible chromogenic compounds, not limiting the invention in any way, are: 3-diethylamino-6-methyl-7-anilino-flouran (U.S. Pat. No. 3,681,390); 2-anilino-3-methyl-6-dibutylamino-fluoran (U.S. Pat. No. 4,510,513) also known as 3-dibutylamino-6-methyl-7-anilino-fluoran; 3-dibutylamino-7-(2-chloroanilino)fluoran; 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-3,5'6-tris(dimethylamino)spiro[9H-fluorene-9,1'(3'H)-isobenzofuran]-3'-one; 7-(1-ethyl-2-methylindol-3-yl)-7 -(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofuro[3,4-b]pyridin-5-one (U.S. Pat. No. 4,246,318); 3-diethylamino-7-(2-chloroanilino)fluoran (U.S. Pat. No. 3,920,510); 3-(N-methylcyclohexylamino)-6-methyl-7-anilinofluoran (U.S. Pat. No. 3,959,571); 7-(1-octyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofuro[3,4-b]pyridin-5-one; 3-diethylamino-7,8-benzofluoran; 3,3-bis(1-ethyl-2-methylindol-3-yl)phthalide; 3-diethylamino-7-anilinofluoran; 3-diethylamino-7-benzylaminofluoran; 3'-phenyl-7-dibenzylamino-2,2'-spiro-di-[2H-1-benzopyran] and mixtures of any of the following.

Examples of eligible acidic developer material include the compounds listed in U.S. Pat. No. 3,539,375 as phenolic reactive material, particularly the monophenols and diphenols. Eligible acidic developer material also includes, without being considered as limiting, the following compounds which may be used individually or in mixtures: 4,4'-isopropylidinediphenol (Bisphenol A); p-hydroxybenzaldehyde; p-hydroxybenzophenone; p-hydroxypropiophenone; 2,4-dihydroxybenzophenone; 1,1-bis(4-hydroxyphenyl)cyclohexane; salicyanilide; 4-hydroxy-2-methylacetophenone; 2-acetylbenzoic acid; m-hydroxyacetanilide; p-hydroxyacetanilide; 2,4-dihydroxyacetophenone; 4-hydroxy-4'-methylbenzophenone; 4,4'-dihydroxybenzophenone; 2,2-bis(4-hydroxyphenyl)-4-methylpentane; benzyl 4-hydroxyphenyl ketone; 2,2-bis(4-hydroxyphenyl)-5-methylhexane; ethyl-4,4-bis(4-hydroxyphenyl)-pentanoate; isopropyl-4,4-bis(4-hydroxyphenyl)pentanoate; methyl-4,4-bis(4-hydroxyphenyl)pentanoate; allyl-4,4-bis(4-hydroxyphenyl)pentanoate; 3,3-bis(4-hydroxyphenyl)-pentane; 4,4-bis(4-hydroxyphenyl)-heptane; 2,2-bis(4-hydroxyphenyl)-1-phenylpropane; 2,2-bis(4-hydroxyphenyl)butane; 2,2'-methylene-bis(4-ethyl-6-tertiarybutyl phenol); 4-hydroxycoumarin; 7-hydroxy-4-methylcoumarin; 2,2'-methylene-bis(4-octyl phenol); 4,4'-sulfonyldiphenol; 4,4'-thiobis(6-tertiarybutyl-m-cresol); methyl-p-hydroxybenzoate; n-propyl-p-hydroxybenzoate; benzyl-p-hydroxybenzoate. Preferred among these are the phenolic developer compounds. More preferred among the phenol compounds are 4,4'-isopropylindinediphenol, ethyl-4,4-bis(4-hydroxyphenyl)-pentanoate, n-propyl-4,4-bis(4-hydroxyphenyl)pentanoate, isopropyl-4,4-bis(4-hydroxyphenyl)pentanoate, methyl-4,4-bis(4-hydroxyphenyl)pentanoate, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, p-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 1,1-bis(4-hydroxyphenyl)cyclohexane, and benzyl-p-hydroxybenzoate. Acid compounds of other kind and types are eligible.

Examples of such other compounds are phenolic novolak resins which are the product of reaction between, for example, formaldehyde and a phenol such as an alkylphenol, e.g., p-octylphenol, or other phenols such as p-phenylphenol, and the like; and acid mineral materials including colloidal silica, kaolin, bentonite, attapulgite, hallosyte, and the like. Some of the polymers and minerals do not melt but undergo color reaction on fusion of the chromogen.

The following examples are given to illustrate some of the features of the present invention and should not be considered as limiting. In these examples all parts or proportions are by weight and all measurements are in the metric system, unless otherwise stated.

In all examples illustrating the present invention a dispersion of a particular system component was prepared by milling the component in an aqueous solution of the binder until a particle size of between about 1 micron and 10 microns was achieved. The milling was accomplished in an attritor or other suitable milling device. The desired average particle size was about 1-3 microns in each dispersion.

The thermally-responsive sheets were made by making separate dispersions of chromogenic material, acidic material and a metal salt of a cinnamic acid of formula I (also referred to as metal cinnamate). The dispersions were mixed in the desired ratios and applied to a support with a wire wound rod and dried. The metal cinnamate can be used as the sole acidic material with a chromogenic material to give a thermally-responsive sheet. Other materials such as sensitizers, fillers, antioxidants, lubricants and waxes can be added if desired. The sheets may be calendered to improve smoothness.

______________________________________Preparation of DispersionDispersion A - Chromogenic Material(Small Media Mill) Parts______________________________________ Chromogenic Material 39.10 Binder, 20% Solution of Polyvinyl 28.12Premix Alcohol (Vinol 205) in Water Water 45.00 Defoamer and Dispersing Agents 0.28Then Add Surfynol 104*, 5% Solution in 12.00and Mill Isopropyl Alcohol______________________________________Dispersion A-1 - Chromogenic Material is N-102,3-diethylamino-6-methyl-7-anilino fluoran.Dispersion A-2 - Chromogenic Material is di-Butyl N-102,3-dibutylamino-6-methyl-7-anilino fluoran.Dispersion A-3 - Chromogenic Material is PSD-150,3-(N--cyclohexyl-N--methylamino)-6-methyl-7-anilino fluoran.Dispersion A-4 - Chromogenic Material is CF-51,3-(N--ethyl-N--tetrahydrofurfurylamino)-6-methyl-7-anilinofluoran.Dispersion A-5 - Chromogenic Material is TH-107,3-dibutylamino-7-(2-chloroanilino)fluoran.Dispersion A-6 - Chromogenic Material is CVL,3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide.Dispersion A-7 - Chromogenic Material is PB-6,7-(1-ethyl-2-methylindol-3-yl)-7-(4,diethylamino-2-ethoxy-phenyl)-5,7-dihydrofuro,[3,4-b]pyridine-5-one.Dispersion A-8 - Chromogenic Material is Octyl PB-6,7-(1-octyl-2-methylindol-3-yl)-7-(4-diethylamino-2-ethoxy-phenyl)-5,7-dihydrofuro[3,4-b]pyridine-5-one.Dispersion A-9 - Chromogenic Material is Green 118,3,5',6-tris(dimethylamino)Spiro[9H--fluorene-9,1'(3'H)-isobenzofuran]-3'-one.______________________________________Dispersion B - Acidic Material(Small Media mill) Parts______________________________________Acidic Material 127.63Binder, 20% Solution of Polyvinyl Alcohol 63.45(Vinol 205) in WaterWater 108.24Defoamer, Nopco NDW* 0.14Dispersing Aid, Surfynol 104* 0.55______________________________________ Dispersion B-1 - Acidic Material is AP-5,2,2-bis(4-hydroxylphenyl)-4-methylpentane.Dispersion B-2 - Acidic Material is Bisphenol A,4,4'-isopropylidenediphenol.Dispersion B-3 - Acidic Material is TG-S,bis(3-allyl-4-hydroxyphenyl)sulfone.Dispersion B-4 - Acidic Material is Bz,benzyl-p-hydroxy benzoate.______________________________________Dispersion C - Sensitizer Material(Small Media Mill) Parts______________________________________Sensitizer 89.25Binder, 20% Solution of Polyvinyl Alcohol 76.13(Vinol 205) in WaterWater 134.10Defoamer, Nopco NDW* 0.11Dispersion Aid, Surfynol 104* 0.42______________________________________Dispersion C-1 - Sensitizer is DPE,1,2-diphenoxyethyane.Dispersion C-2 - Sensitizer is AAOT,acetoacet-o-toluidine.Dispersion C-3 - Sensitizer is BBP,p-benzyl biphenyl.Dispersion C-4 - Sensitizer is PHNT,phenyl-1-hydroxy-2-naphthoate.______________________________________Dispersion D - Metal Salt(Small Media Mill) Parts______________________________________Metal Salt 13.60Binder, 20% Solution of Polyvinyl Alcohol 11.60(Vinol 205) in WaterWater 54.72Defoamer, Nopco NDW* 0.02Dispersing Aid, Surfynol 104* 0.06______________________________________Dispersion D-1 - Metal Salt is zinc(cinnamate).sub.2.Dispersion D-2 - Metal Salt is zinc(2-chlorocinnamate).sub.2.Dispersion D-3 - Metal Salt is zinc(3-chlorocinnamate).sub.2.Dispersion D-4 - Metal Salt is zinc(4-chlorocinnamate).sub.2.Dispersion D-5 - Metal Salt is zinc(2-methoxycinnamate).sub.2.Dispersion D-6 - Metal Salt is zinc(3-methoxycinnamate).sub.2 .Dispersion D-7 - Metal Salt is zinc(4-methoxycinnamate).sub.2.Dispersion D-8 - Metal Salt is zinc(3,4,5-trimethoxycinna-mate).sub.2.Dispersion D-9 - Metal Salt is zinc(4-methylcinnamate).sub.2.Dispersion D-10 - Metal Salt is zinc(2-nitrocinnamate).sub.2.Dispersion D-11 - Metal Salt is zinc(3-nitrocinnamate).sub.2.Dispersion D-12 - Metal Salt is zinc(.alpha.-phenylcinnamate).sub.2.Dispersion D-13 - Metal Salt is zinc(.alpha.-methylcinnamate).sub.2.Dispersion D-14 - Metal Salt is zinc(4-phenylbutyrate).sub.2.Dispersion D-15 - Metal Salt is zinc(styrlacetate).sub.2.Dispersion D-16 - Metal Salt is zinc(cis-o-methoxycinna-mate).sub.2.Dispersion D-17 - Metal Salt is calcium(cinnamate).sub.2.Dispersion D-18 - Metal Salt is zinc(phenylacetate).sub.2.Dispersion D-19 - Metal Salt is zinc(hydrocinnamate).sub.2.______________________________________Dispersion E - Metal Stearate(Attritor) Parts______________________________________Metal Stearate 13.60Binder, 20% Solution of Polyvinyl Alcohol 11.60(Vinol 205) in WaterWater 54.72Defoamer, Nopco NDW* 0.02Dispersing Aid, Surfynol 104* 0.06______________________________________Dispersion E-1 - Metal Stearate is Zinc Stearate.Dispersion E-2 - Metal Stearate is Aluminum Stearate.Dispersion E-3 - Metal Stearate is Calcium Stearate.Dispersion E-4 - Metal Stearate is Barium Stearate.Dispersion E-5 - Metal Stearate is Magnesium Stearate.Dispersion E-6 - Metal Stearate is Lithium Stearate.______________________________________Test FormulationsControl-1 Parts______________________________________Dispersion A-1 0.95Dispersion B-1 2.35Dispersion C-1 3.36Filler 1.40Dispersion E-1 1.76PVA (10% Solution Vinol 325 in Water) 6.30Water 8.88______________________________________Control-2 - Same as Control-1 but use Dispersion A-2 in placeof Dispersion A-1.Control-3 - Same as Control-1 but use Dispersion A-3 in placeof Dispersion A-1.Control-4 - Same as Control-1 but use Dispersion A-4 in placeof Dispersion A-1.Control-5 - Same as Control-1 but use Dispersion A-5 in placeof Dispersion A-1.Control-6 - Same as Control-1 but use Dispersion A-6 in placeof Dispersion A-1.Control-7 - Same as Control-1 but use Dispersion A-7 in placeof Dispersion A-1.Control-8 - Same as Control-1 but use Dispersion A-8 in placeof Dispersion A-1.Control-9 - Same as Control-1 but use Dispersion A-9 in placeof Dispersion A-1.Control-10 - Same as Control-1 but use Dispersion C-2 in placeof Dispersion C-1.Control-11 - Same as Control-1 but use Dispersion C-3 in placeof Dispersion C-1.Control-12 - Same as Control-1 but use Dispersion C-4 in placeof Dispersion C-1.Control-13 - Same as Control-1 but use Dispersion B-2 in placeof Dispersion B-1.Control-14 - Same as Control-1 but use Dispersion B-3 in placeof Dispersion B-1.Control-15 - Same as Control-1 but use Dispersion B-4 in placeof Dispersion B-1.______________________________________ Parts______________________________________Example 1-1Dispersion A-1 0.57Dispersion D-1 3.53Dispersion C-1 2.01Filler 0.84Dispersion E-1 1.06PVA (10% Solution Vinol 325 in Water) 3.78Water 3.28Example 1-2Dispersion A-1 0.57Dispersion B-1 0.71Dispersion D-1 1.76Dispersion C-1 2.02Filler 0.84Dispersion E-1 1.06PVA (10% Solution Vinol 325 in Water) 3.54Water 4.50______________________________________Example 1-3 - Same as Example 1-2 but using Dispersion D-2 inplace of Dispersion D-1.Example 1-4 - Same as Example 1-2 but using Dispersion D-3 inplace of Dispersion D-1.Example 1-5 - Same as Example 1-2 but using Dispersion D-4 inplace of Dispersion D-1.Example 1-6 - Same as Example 1-2 but using Dispersion D-5 inplace of Dispersion D-1.Example 1-7 - Same as Example 1-2 but using Dispersion D-6 inplace of Dispersion D-1.Example 1-8 - Same as Example 1-2 but using Dispersion D-7 inplace of Dispersion D-1.Example 1-9 - Same as Example 1-2 but using Dispersion D-8 inplace of Dispersion D-1.Example 1-10 - Same as Example 1-2 but using Dispersion D-9 inplace of Dispersion D-1.Example 1-11 - Same as Example 1-2 but using Dispersion D-10in place of Dispersion D-1.Example 1-12 - Same as Example 1-2 but using Dispersion D-11in place of Dispersion D-1.Example 1-13 - Same as Example 1-2 but using Dispersion E-2 inplace of Dispersion E-1.Example 1-14 - Same as Example 1-2 but using Dispersion E-3 inplace of Dispersion E-1.Example 1-15 - Same as Example 1-2 but using Dispersion E-4 inplace of Dispersion E-1.Example 1-16 - Same as Example 1-2 but using Dispersion E-5 inplace of Dispersion E-1.Example 1-17 - Same as Example 1-2 but using Dispersion E-6 inplace of Dispersion E-1.Example 1-18 - Same as Example 1-2 but using Dispersion D-12in place of Dispersion D-1.Example 1-19 - Same as Example 1-2 but using Dispersion D-13in place of Dispersion D-1.Example 1-20 - Same as Example 1-2 but using Dispersion D-14in place of Dispersion D-1.Example 1-21 - Same as Example 1-2 but using Dispersion D-15in place of Dispersion D-1.Example 1-22 - Same as Example 1-2 but using Dispersion D-16in place of Dispersion D-1.Example 1-23 - Same as Example 1-2 but using Dispersion D-17in place of Dispersion D-1.Example 1-24 - Same as Example 1-2 but using Dispersion D-18in place of Dispersion D-1.Example 1-25 - Same as Example 1-2 but using Dispersion D-19in place of Dispersion D-1.Example 2-1 - Same as Example 1-2 but using Dispersion A-2 inplace of Dispersion A-1.Example 3-1 - Same as Example 1-2 but using Dispersion A-3 inplace of Dispersion A-1.Example 4-1 - Same as Example 1-2 but using Dispersion A-4 inplace of Dispersion A-1.Example 5-1 - Same as Example 1-2 but using Dispersion A-5 inplace of Dispersion A-1.Example 6-1 - Same as Example 1-2 but using Dispersion A-6 inplace of Dispersion A-1.Example 7-1 - Same as Example 1-2 but using Dispersion A-7 inplace of Dispersion A-1.Example 8-1 - Same as Example 1-2 but using Dispersion A-8 inplace of Dispersion A-1.Example 9-1 - Same as Example 1-2 but using Dispersion A-9 inplace of Dispersion A-1.Example 10-1 - Same as Example 1-2 but using Dispersion C-2 inplace of Dispersion C-1.Example 11-1 - Same as Example 1-2 but using Dispersion C-3 inplace of Dispersion C-1.Example 12-1 - Same as Example 1-2 but using Dispersion C-4 inplace of Dispersion C-1.Example 13-1 - Same as Example 1-2 but using Dispersion B-2 inplace of Dispersion B-1.Example 14-1 - Same as Example 1-2 but using Dispersion B-3 inplace of Dispersion B-1.Example 15-1 - Same as Example 1-2 but using Dispersion B-4 inplace of Dispersion B-1.______________________________________ The metal stearate function or lubricants Dispersion E1 through E6 exemplify the most commonly used lubricants. *(Nopco NDW is a sulfonated castor oil produced by Nopco Chemical Company Surfynol 104 is a ditertiary acetylene glycol surface active agent produced by Air Products and Chemicals, Inc.)

These examples are illustrative and are not intended to be limiting. The chromogenic materials may be mixed and ratios of other materials varied.

The thermal performance of the sheets were checked by contact with a heated metal block for 5 seconds, imaging on a laboratory printer or imaging on commercial facisimile unit. The color produced was measured with a Macbeth RD-514 densitometer, No. 106 visual wratten filter. A low value indicated little color is produced and the higher the value, the more color was produced.

TABLE 1__________________________________________________________________________Thermal Responses__________________________________________________________________________I. Stepwedge Temperature .degree.F./Macbeth ReadingExample 300 275 260 245 230 215 200 185 170 155 140__________________________________________________________________________Control-1 1.41 1.44 1.45 1.46 1.44 1.39 1.31 0.66 0.08 0.03 0.03Example 1-1 1.23 1.28 1.28 1.29 1.29 1.26 1.29 0.91 0.14 0.02 0.02Example 1-2 1.36 1.40 1.40 1.41 1.39 1.39 1.38 1.16 0.45 0.04 0.02Control 1-2 1.39 1.42 1.40 1.41 1.42 1.33 1.23 0.48 0.03 0.02 0.02Example 2-1 1.33 1.38 1.41 1.39 1.39 1.36 1.33 1.09 0.24 0.03 0.03Control-3 1.39 1.37 1.37 1.36 1.35 1.25 1.13 0.47 0.11 0.05 0.02Example 3-1 1.36 1.38 1.36 1.35 1.33 1.27 1.27 0.98 0.36 0.04 0.01Control-4 1.35 1.41 1.42 1.41 1.39 1.33 1.19 0.67 0.09 0.03 0.02Example 4-1 1.37 1.36 1.37 1.38 1.35 1.37 1.36 1.08 0.46 0.03 0.03Control-5 1.32 1.35 1.35 1.35 1.29 1.18 1.05 0.18 0.05 0.02 0.02Example 5-1 1.30 1.29 1.30 1.30 1.29 1.29 1.27 0.94 0.36 0.01 0.01Control-6 1.41 1.41 1.41 1.40 1.34 1.20 1.14 0.71 0.14 0.03 0.03Example 6-1 1.44 1.43 1.43 1.43 1.41 1.42 1.40 1.15 0.46 0.03 0.03Control-7 1.42 1.44 1.43 1.44 1.42 1.40 1.31 1.03 0.30 0.04 0.04Example 7-1 1.39 1.40 1.41 1.41 1.40 1.39 1.42 1.30 0.67 0.08 0.02Control-8 1.42 1.41 1.43 1.42 1.41 1.36 1.26 0.94 0.64 0.23 0.05Example 8-1 1.35 1.39 1.38 1.38 1.39 1.38 1.37 1.26 1.02 0.28 0.06Control-9* 0.78 0.78 0.76 0.73 0.55 0.44 0.34 0.06 0.04 0.04 0.04Example 9-1* 1.15 1.14 1.13 1.14 1.14 1.12 1.12 0.98 0.32 0.02 0.02Control-10 1.25 1.26 1.24 1.25 1.21 1.22 1.20 1.19 0.90 0.03 0.03Example 10-1 1.30 1.31 1.32 1.31 1.30 1.30 1.26 1.15 0.82 0.05 0.03Control-11 1.35 1.34 1.34 1.34 1.27 1.23 1.07 0.76 0.30 0.01 0.01Example 11-1 1.29 1.31 1.29 1.29 1.28 1.28 1.28 1.23 0.73 0.08 0.02Control-12 1.34 1.35 1.35 1.34 1.28 1.23 1.07 0.60 0.04 0.02 0.02Example 12-1 1.35 1.33 1.33 1.33 1.30 1.28 1.25 0.82 0.13 0.02 0.02Control-13 1.41 1.42 1.39 1.39 1.40 1.39 1.36 1.10 0.26 0.07 0.04Example 13-1 1.40 1.40 1.40 1.40 1.39 1.37 1.36 1.10 0.47 0.13 0.08Control-14 1.43 1.44 1.45 1.43 1.41 1.43 1.42 1.17 0.69 0.20 0.18Example 14-1 1.41 1.41 1.42 1.42 1.43 1.43 1.42 1.22 0.63 0.22 0.16Control-15 1.39 1.38 1.39 1.39 1.38 1.38 1.38 1.36 1.30 0.33 0.10Example 15-1 1.38 1.38 1.40 1.40 1.38 1.39 1.37 1.32 1.24 0.74 0.28__________________________________________________________________________II. Dynamic Tester (18 Volt) Pulse Time ms/Macbeth ReadingExample 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3__________________________________________________________________________Control-1 0.25 0.48 0.82 1.13 1.20 1.32 1.33 1.35 1.33 1.34Example 1-1 0.07 0.25 0.52 0.71 1.07 1.23 1.25 1.26 1.28 1.30Example 1-2 0.20 0.50 0.93 1.18 1.31 1.33 1.33 1.37 1.38 1.35Control-2 0.19 0.45 0.76 1.05 1.25 1.29 1.37 1.35 1.36 1.36Example 2-1 0.22 0.46 0.82 1.04 1.17 1.28 1.28 1.30 1.33 1.34Control-3 0.17 0.39 0.75 0.95 1.13 1.27 1.27 1.30 1.35 1.33Example 3-1 0.20 0.43 0.68 0.98 1.11 1.20 1.24 1.25 1.29 1.30Control-4 0.23 0.47 0.93 1.26 1.33 1.33 1.34 1.35 1.36 1.36Example 4-1 0.22 0.50 0.80 1.14 1.26 1.34 1.34 1.36 1.35 1.35Control-5 0.17 0.42 0.86 1.04 1.21 1.23 1.22 1.24 1.24 1.29Example 5-1 0.21 0.50 0.85 1.06 1.20 1.26 1.27 1.26 1.27 1.25Control-6 0.13 0.35 0.62 0.88 1.12 1.19 1.23 1.27 1.30 1.31Example 6-1 0.10 0.26 0.51 0.84 1.12 1.20 1.23 1.30 1.33 1.32Control-7 0.30 0.59 0.97 1.26 1.36 1.39 1.41 1.42 1.42 1.43Example 7-1 0.30 0.57 0.97 1.19 1.33 1.37 1.38 1.39 1.40 1.41Control-8 0.37 0.68 1.03 1.32 1.37 1.40 1.42 1.41 1.41 1.40Example 8-1 0.30 0.57 0.97 1.19 1.33 1.37 1.38 1.39 1.40 1.41Control-10 0.18 0.39 0.64 0.88 1.13 1.22 1.26 1.26 1.26 1.26Example 10-1 0.17 0.39 0.67 0.99 1.18 1.26 1.28 1.30 1.32 1.33Control-11 0.19 0.45 0.80 1.09 1.25 1.30 1.31 1.31 1.32 1.33Example 11-1 0.23 0.48 0.77 1.02 1.23 1.31 1.31 1.31 1.32 1.34Control-12 0.13 0.36 0.57 0.85 1.10 1.21 1.25 1.28 1.28 1.30Example 12-1 0.14 0.30 0.58 0.82 1.05 1.18 1.26 1.30 1.32 1.32Control-13 0.24 0.49 0.85 1.06 1.23 1.32 1.33 1.34 1.33 1.34Example 13-1 0.27 0.51 0.87 1.06 1.28 1.29 1.31 1.34 1.34 1.34Control-14 0.34 0.60 0.98 1.22 1.30 1.34 1.36 1.37 1.38 1.38Example 14-1 0.37 0.64 1.02 1.31 1.37 1.38 1.39 1.39 1.39 1.39__________________________________________________________________________III. Facsimile (Hi Fax 700) Areas/Macbeth Reading Example Top Left Bottom Right__________________________________________________________________________ Control-1 1.35 1.33 1.32 1.34 Example 1-1 1.24 1.24 1.24 1.18 Example 1-2 1.35 1.34 1.34 1.31 Control-2 1.31 1.31 1.28 1.25 Example 2-1 1.36 1.31 1.31 1.24 Control-3 1.20 1.23 1.24 1.17 Example 3-1 1.19 1.19 1.17 1.13 Control-4 1.35 1.31 1.32 1.30 Example 4-1 1.34 1.33 1.34 1.27 Control-5 1.27 1.27 1.29 1.25 Example 5-1 1.25 1.23 1.26 1.24 Control-6 1.20 1.20 1.26 1.24 Example 6-1 1.24 1.24 1.26 1.26 Control-7 1.37 1.39 1.38 1.40 Example 7-1 1.36 1.34 1.35 1.35 Control-8 1.38 1.41 1.40 1.40 Example 8-1 1.36 1.34 1.35 1.33 Control-10 1.23 1.23 1.23 1.21 Example 10-1 1.26 1.24 1.25 1.24 Control-11 1.31 1.29 1.29 1.29 Example 11-1 1.28 1.29 1.28 1.28 Control-12 1.24 1.23 1.27 1.23 Example 12-1 1.19 1.17 1.21 1.20 Control-13 1.34 1.32 1.33 1.31 Example 13-1 1.32 1.36 1.36 1.31 Control-14 1.39 1.38 1.35 1.36 Example 14-1 1.38 1.36 1.36 1.36 Control-15 1.38 1.34 1.38 1.35 Example 15-1 1.35 1.30 1.33 1.34__________________________________________________________________________ *Sample has color absorbance beyond the reading limits of the Macbeth RD514.

The data of Table 1 present a comparison of the thermal responses of thermally responsive recording materials of the invention containing a metal salt of a cinnamic acid and structurally related compounds of formulas (I) and (II) compared to corresponding thermally-responsive recording material in which metal salt of formulas (I) and (II) is omitted. Recording material with the metal salt compounds of formulas (I) and (II) clearly do not detract from the thermal responsiveness of the recording materials. More often the responsiveness is increased. As the tables which follow show, image retention is surprisingly improved. The resistance to image erasure was checked by placing a fingerprint rich in skin oil on the imaged area. The area was observed and any changes in image quality noted.

The ranking scale for image resistance is 0-4.

0=No change in image quality. 1=Image density reduced but no erasure. 2=Image density reduced and slight erasure. 3=Moderate erasure of image. 4=Complete erasure of image.

The same observations were made using a plastic film, specifically in this case Borden Resenite RMF-61HY. A piece of film larger than the imaged area is placed on the sample and weighted with a flat surface. Cooking oil and internal phase solvent (also referred to as IP solvent) were tested by rubbing a drop of the oil between two finger tips and then pressing on the imaged area.

TABLE 2______________________________________Image Resistance______________________________________I. Stepwedge - Skin Oil Image Time ofExample Temp. .degree.F. Test (Day) Result______________________________________Control-1 300 30 4 170 30 4 300 4 3 170 4 4Example 1-1 300 30 1 170 30 4Example 1-2 300 30 1 170 30 2Example 1-3 300 12 1Example 1-4 300 31 1 170 31 2Example 1-5 300 31 1 170 31 3Example 1-6 300 4 1 170 4 2Example 1-7 300 4 1 170 4 1Example 1-8 300 4 1 170 4 4Example 1-9 300 4 1 170 4 2Example 1-10 300 4 1 170 4 4Example 1-11 300 4 1 170 4 3Example 1-12 300 4 1 170 4 1Example 1-13 300 25 2 170 25 3Example 1-14 300 25 1 170 25 3Example 1-15 300 25 1 170 25 3Example 1-16 300 25 1 170 25 3Example 1-17 300 25 2 170 25 3Example 1-18 300 34 1 170 34 4Example 1-19 300 2 1 170 2 2Example 1-21 300 2 1 170 2 2Example 1-22 300 5 1 170 5 2Example 1-23 300 2 1 170 2 4Control-2 300 30 4Example 2-1 300 30 2Control-3 300 4 1 185 4 4Example 3-1 300 4 1 185 4 1Control-4 300 4 1 185 4 3Example 4-1 300 4 1 185 4 1Control-5 300 4 4 200 4 4Example 5-1 300 4 1 170 4 4Control-6 300 11 4Example 6-1 300 11 2Control-7 300 11 0Example 7-1 300 11 1Control-8 300 11 2Example 8-1 300 11 1Control-9 300 4 3 200 4 4Example 9-1 300 4 1 200 4 1Control-10 300 18 1Example 10-1 300 18 1Control-11 300 18 3Example 11-1 300 18 1Control-12 300 18 2Example 12-1 300 18 1Control-13 300 18 1 170 18 4Example 13-1 300 18 1 170 18 3Control-14 300 18 1 170 18 0Example 14-1 300 18 1 170 18 0Control-15 300 5 4 170 5 4Example 15-1 300 5 1 170 5 1______________________________________II. Facsimile______________________________________A. Skin Oil Area of TimeExample Test (Day) Result______________________________________Control-1 Bottom 22 4 Bottom 4 4Example 1-1 Bottom 22 4Example 1-2 Bottom 30 1Example 1-3 Bottom 6 1Example 1-4 Bottom 31 1Example 1-5 Bottom 31 3Example 1-6 Bottom 4 1Example 1-7 Bottom 4 1Example 1-8 Bottom 4 1Example 1-9 Bottom 4 1Example 1-10 Bottom 4 2Example 1-11 Bottom 4 1Example 1-12 Bottom 4 1Example 1-13 Bottom 22 3Example 1-14 Bottom 22 1Example 1-15 Bottom 22 1Example 1-16 Bottom 22 1Example 1-17 Bottom 22 2Example 1-18 Bottom 31 1Example 1-19 Bottom 16 1Example 1-21 Bottom 16 4Example 1-22 Bottom 5 1Example 1-23 Bottom 16 3Control-2 Bottom 22 4Example 2-1 Bottom 30 1Control-3 Bottom 3 4Example 3-1 Bottom 3 1Control-4 Bottom 3 2Example 4-1 Bottom 3 0Control-5 Bottom 3 4Example 5-1 Bottom 3 2Control-6 Bottom 11 4Example 6-1 Bottom 11 1Control-7 Bottom 11 3Example 7-1 Bottom 11 1Control-8 Bottom 11 2Example 8-1 Bottom 11 0Control-10 Bottom 15 3Example 10-1 Bottom 15 1Control-11 Bottom 15 4Example 11-1 Bottom 15 1Control-12 Bottom 15 4Example 12-1 Bottom 15 2Control-13 Bottom 18 1Example 13-1 Bottom 18 1Control-14 Bottom 18 1Example 14-1 Bottom 18 1Control-15 Bottom 5 4Example 15-1 Bottom 5 1______________________________________B. Plastic Film Area of TimeExample Test (Hour) Result______________________________________Control-1 Top 30 4 24 4Example 1-1 Top 30 2Example 1-2 Top 30 1Example 1-3 Top 24 3Example 1-4 Top 24 1Example 1-5 Top 24 4Example 1-6 Top 24 2Example 1-7 Top 24 1Example 1-8 Top 24 1Example 1-9 Top 24 3Example 1-l0 Top 24 2Example 1-11 Top 24 2Example 1-12 Top 24 1Example 1-13 Top 24 2Example 1-14 Top 24 1Example 1-15 Top 24 2Example 1-16 Top 24 1Example 1-17 Top 24 3Example 1-18 Top 24 2Example 1-19 Top 24 1Example 1-21 Top 25 2Example 1-22 Top 25 2Example 1-23 Top 25 2Control-2 Top 30 4Example 2-1 Top 30 2Control-3 Top 24 4Example 3-1 Top 24 1Control-4 Top 24 3Example 4-1 Top 24 1Control-5 Top 24 4Example 5-1 Top 24 2Control-6 Top 24 4Example 6-1 Top 24 2Control 7 Top 24 3 -Example 7-1 Top 24 2Control-8 Top 24 3Example 8-1 Top 24 2Control-10 Top 24 4Example 10-1 Top 24 1Control-11 Top 24 4Example 11-1 Top 24 1Control-12 Top 24 4Example 12-1 Top 24 1Control-13 Top 22 3Example 13-1 Top 22 1Control-14 Top 22 1Example 14-1 Top 22 1Control-15 Top 24 3Example 15-1 Top 24 1______________________________________C. Cooking Oil Area of TimeExample Test (Day) Result______________________________________Control-1 Top 14 4 2 4Example 1-2 Top 14 1Example 1-3 Top 4 3Example 1-4 Top 39 1Example 1-5 Top 4 3Example 1-6 Top 2 3Example 1-7 Top 2 1Example 1-8 Top 2 2Example 1-9 Top 2 3Example 1-10 Top 2 3Example 1-11 Top 2 2Example 1-12 Top 2 1Example 1-13 Top 25 3Example 1-14 Top 25 2Example 1-15 Top 25 2Example 1-16 Top 25 1Example 1-17 Top 25 3Example 1-18 Top 31 3Example 1-19 Top 16 1Example 1-21 Top 16 3Example 1-22 Top 5 3Example 1-23 Top 16 3Control-2 Top 10 4Example 2-1 Top 10 1Control-3 Top 3 4Example 3-1 Top 3 1Control-4 Top 3 3Example 4-1 Top 3 1Control-5 Top 3 4Example 5-1 Top 3 2Control-6 Top 14 4Example 6-1 Top 14 2Control-7 Top 14 3Example 7-1 Top 14 2Control-8 Top 14 4Example 8-1 Top 14 2Control-10 Top 18 4Example 10-1 Top 18 1Control-11 Top 18 4Example 11-1 Top 18 1Control-12 Top 18 4Example 12-1 Top 18 2Control-13 Top 22 1Example 13-1 Top 22 1Control-14 Top 22 1Example 14-1 Top 22 1Example-15 Top 5 4Example 15-1 Top 5 1______________________________________D. IP Solvent Area of TimeExample Test (Day) Result______________________________________Control-1 Top 14 4 2 4Example 1-2 Top 14 1Example 1-3 Top 4 3Example 1-4 Top 39 1Example 1-5 Top 4 1Example 1-6 Top 2 1Example 1-7 Top 2 1Example 1-8 Top 2 1Example 1-9 Top 2 2Example 1-10 Top 2 2Example 1-11 Top 2 1Example 1-12 Top 2 1Example 1-13 Top 25 3Example 1-14 Top 25 2Example 1-15 Top 25 2Example 1-16 Top 25 2Example 1-17 Top 25 3Example 1-18 Top 31 2Example 1-19 Top 16 1Example 1-21 Top 16 3Example 1-22 Top 5 2Example 1-23 Top 16 3Control-2 Top 10 4Example 2-1 Top 10 1Control-3 Top 3 4Example 3-1 Top 3 0Control-4 Top 3 4Example 4-1 Top 3 0Control-5 Top 3 4Example 5-1 Top 3 1Control-6 Top 14 4Example 6-1 Top 14 1Control-7 Top 14 2Example 7-1 Top 14 1Control-8 Top 14 4Example 8-1 Top 14 1Control-10 Top 18 2Example 10-1 Top 18 1Control-11 Top 18 4Example 11-1 Top 18 1Control-12 Top 18 4Example 12-1 Top 18 1Control-13 Top 21 0Example 13-1 Top 21 2Control-14 Top 21 1Example 14-1 Top 21 1Control-15 Top 5 4Example 15-1 Top 5 1______________________________________

From the data of Table 2 it is readily apparent that thermally-sensitive recording materials containing a metal salt of a cinnamic acid and structurally related compounds of formulas (I) and (II) possess improved resistance to image fade compared to corresponding thermally-sensitive recording materials in which the metal salt of a compound of formula (I) or (II) is omitted.

The principles, preferred embodiments, and modes of operation of the present invention have been described in the foregoing specification. The invention which is intended to be protected herein, however, is not to be construed as limited to the particular forms disclosed, since these are to be regarded as illustrative rather than restrictive. Variations and changes can be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. A non-reversible thermally-responsive record material comprising a support member bearing a thermally-sensitive color-forming composition consisting essentially of

a chromogenic material and an acidic developer material in contiguous relationship, whereby the melting, softening or sublimation of either material produces a change in color by reaction between the two,

a metal salt of a compound of the formula ##STR5## wherein M is a metal selected from Zn, Ca, Sn, Ni, Cu, Al, Co, and Mg; wherein m corresponds to the valency of M;

wherein n is 1 to 3;

wherein R.sup.1 is selected from hydrogen, halogen, alkyl, oxyalkyl, or NO.sub.2, with the proviso that the alkyl group is of 1 to 5 carbons;

wherein R.sup.2 is selected from hydrogen, alkyl, or aryl, with the proviso that the alkyl group is of 1-5 carbon; and

a suitable binder therefor.

2. The record material according to claim 1 wherein M is selected from Zn, Ca, Sn, Ni, Cu, Co, and Mg, wherein m is 2 and wherein n is 1.

3. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), M is zinc.

4. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I) M is calcium.

5. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), R.sup.1 is nitro.

6. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), R.sup.1 is chlorine.

7. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), R.sup.1 is methyl.

8. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), R.sup.1 is methoxy.

9. The record material of claim 1 wherein the acid developer material is the metal salt of a cinnamic acid of formula (I).

10. The record material of claim 1 wherein the metal salt of a cinnamic acid is zinc (.alpha.-phenylcinnamate).sub.2.

11. The record material of claim 1 wherein the metal salt of a cinnamic acid is zinc (.alpha.-methylcinnamate).sub.2.

12. The record material of claim 1 wherein in the metal salt of a cinnamic acid of formula (I), R.sup.2 is hydrogen.

13. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (cinnamate).sub.2.

14. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (2-chlorocinnamate).sub.2.

15. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (3-chlorocinnamate).sub.2.

16. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (4-chlorocinnamate).sub.2.

17. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (2-methoxycinnamate).sub.2.

18. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (3-methoxycinnamate).sub.2.

19. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (4-methoxycinnamate).sub.2.

20. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (3,4,5-trimethoxycinnamate).sub.2.

21. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (4-methylcinnamate).

22. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (2-nitrocinnamate).sub.2.

23. The record material of claim 12 wherein the metal salt of a cinnamic acid is zinc (3-nitrocinnamate).sub.2.

24. The record material of claim 1 in which the acidic developer material is a phenol compound.

25. The record material of claim 24 in which the phenol compound is selected from the group consisting of 4,4'-isopropylindinediphenol, ethyl-4,4-bis(4-hydroxyphenyl)-pentanoate, n-propyl-4,4-bis(4-hydroxyphenyl)pentanoate, isopropyl-4,4-bis(4-hydroxyphenyl)pentanoate, methyl-4,4-bis(4-hydroxyphenyl)-pentanoate, allyl-4,4-bis(hydroxyphenyl)pentanoate, 2,2-bis(4-hydroxyphenyl)-4-methylpentane, p-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxyphenyl)-5-methylhexane, benzyl-p-hydroxybenzoate, and mixtures thereof.

26. The record material of claim 24 in which the phenol compound is 2,2-bis(4-hydroxyphenyl)-4-methylpentane.

27. The record material of claim 24 in which the phenol compound is benzyl-p-hydroxybenzoate.

28. The record material of claim 1 wherein in the metal salt of the compound of the formula (I), M is zinc.

29. The record material of claim 1 wherein in the metal salt of the compound of the formula (I), M is calcium.

30. The record material of claim 1 in which the chromogenic material is selected from the group consisting of 3-diethylamino-6-methyl-7-anilinofluoran; 7-(1-ethyl-2-methyl-indol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofur 3[3,4-b]pyridin-5-one; 3-diethylamino-7-(2-chloroanilino)fluoran; 3-(N-methylcyclohexylamino)-6-methyl-7-anilinofluoran; 7-(1-octyl-2-methyl-indol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofur o[3,4-b]pyridin-5-one; 3'-phenyl-7-dibenzylamino-2,2'-spiro-di-[2H-1-benzopyran]; 3-dibutylamino-6-methyl-7-anilinofluoran; 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-anilinofluoran; 3-dibutylamino-7-(2-chloroanilino)fluoran; 3,3-bis(4-dimethylaminophenyl)-6-dimethylaminophthalide; 7-(1-ethyl-2-methyl-indol-3-yl)-7-(4-diethylamino-2-ethoxyphenyl)-5,7-dihydrofur o,[3,4-b]pyridine-5-one; 3,5',6-tris(dimethylamino)spiro[9H-fluorene-9,1'(3'H)-isobenzofuran]3'-one, and mixtures thereof.

31. The record material of claim 1 comprising in addition a sensitizer.

32. The record material of claim 31 wherein the sensitizer is selected from 1,2-diphenoxyethane, acetoacet-o-toluedine, p-benzylbiphenyl, and phenyl-1-hydroxy-2-naphthoate.