JPH09156219A - Multicolor thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen a developable hue and to reduce the discoloration of an undeveloped color part at a time of optical fixing by forming two or more thermal color forming layers forming mutually different hues on a support and adding an oxidation color forming type leuco dye, an oxidizing agent and a photoreduction to one of the thermal color forming layers. SOLUTION: Two or more thermal color forming layers forming mutually different hues are formed on a support. An oxidation color forming type leuco dye composed of one kind of a compd. selected from 8-diethylamino-11-(2- methoxycarbonylphenyl)benzo [a] xanthene, 8-diethylamino-11-(2- butoxycarbonylphenyl)benzo [a] xanthene, and 8-diethylamino-11-(2- butoxycarbonylphenyl)benzo [a[ xanthene, an oxidizing agent and a photoreduction agent are added to one of the thermal color forming layers. By this constitution, a developable hue is widened and the discoloration of an undeveloped color part at a time of optical fixing can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor thermosensitive recording material having two or more thermosensitive coloring layers for recording images each of which develops a different color tone. More specifically, the present invention relates to a multicolor thermosensitive recording material in which at least one of the thermosensitive color developing layers can be fixed by irradiation with light, has a wide hue that can be developed, and has very little discoloration during photofixing. .

[0002]

2. Description of the Related Art A thermosensitive recording material generally comprises a support made of paper, synthetic paper, plastic film, or the like, on which a thermosensitive coloring layer containing a coloring substance, a developer and an adhesive as main components is provided. Thus, a color-recorded image can be obtained by reacting these color-forming substances with a color developer by thermal energy. Such a thermal recording method has advantages that the recording apparatus is compact and inexpensive, and that maintenance is easy.
Not only as a recording medium for scientific measuring instruments, but also various printers for POS labels, CAD, CRT medical images, etc.
Widely used as an output means for plotters. Such heat-sensitive recording materials are required to be diversified in performance required as their applications are expanded. For example, higher sensitivity, image stabilization, and multicolor recording are required. In particular, various recording materials have been researched and proposed so far because of their wide range of applications for multicolor recording.

For example, JP-A-48-86543,
Also, JP-A-51-146239 and the like describe recording materials in which two heat-sensitive color-forming layers capable of forming different colors are provided and two distinguishable colors are obtained by applying different amounts of heat. Such a method has an advantage that it can be manufactured at a relatively low cost, but since the low-temperature color-developing layer cannot be fixed, each layer cannot be independently colored. That is, since not only the high temperature layer but also the low temperature layer develops at the time of high temperature color development, there is a drawback that it is not possible to produce only the high temperature color layer. On the other hand, JP-A-55-8
1193 and Japanese Patent Application Laid-Open No. 2-80287 use a decolorizing agent having a decoloring effect on the color development system of a low temperature color development layer at the time of high temperature heating, so that the color tone of only the high temperature color development layer becomes high at the time of high temperature heating. A method of obtaining is disclosed.
As a result, only the low temperature coloring layer can be colored during low temperature coloring, and the color tone of only the high temperature coloring layer can be expressed during high temperature coloring. However, this method has a drawback that both the high-temperature color developing layer and the low-temperature color developing layer cannot be colored at the same time, and the color tone is also limited. Further, an attempt to make multicolor by a combination of heat and light by utilizing the property that a diazo compound decomposes by light and the property that the diazo compound reacts with a coupler to develop a color is disclosed in JP-A-60-242093. And Japanese Patent Application Laid-Open No. 61-40192. In this system, the color tone of each color-forming layer can be obtained independently, and it is also possible to color each layer at the same time, so that the color tone by so-called color mixing can be developed. However, at the time of optical fixing, it is unavoidable that the white paper portion develops a light color, and so-called stain tends to occur.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems of conventional multicolor thermosensitive recording materials, has a wide range of hues that can be developed, and causes little discoloration of the undeveloped portion during optical fixing. It is intended to provide materials. Further, the present invention is intended to provide a multicolor heat-sensitive recording material which is excellent in light resistance with little discoloration of the uncolored portion due to sunlight, ultraviolet rays and the like.

[0005]

The multicolor thermosensitive recording material of the present invention comprises a support and two or more thermosensitive color forming layers formed thereon and coloring in different color tones. At least one layer of the coloring layer contains an oxidative coloring type leuco dye, an oxidizing agent and a photoreducing agent. In the multicolor heat-sensitive recording material of the present invention, it is preferable that at least one of the oxidative color-forming leuco dye, the oxidizing agent and the photoreducing agent is encapsulated in microcapsules. In the multicolor heat-sensitive recording material of the present invention, it is preferable that the oxidative coloring leuco dye comprises at least one compound selected from the compounds represented by the following general formulas (I) and (II).

Embedded image[However, in the formula (I), R¹Is a hydrogen atom, C₁~ C₆Chain A
Luquil, C_Three~ C₆Cyclic alkyl, substituted or unsubstituted C₇
~ C₂₀Aralkyl group, substituted or unsubstituted phenyl group, or
C_Two~ C_TenRepresents an alkoxyalkyl group, X¹~ X⁸Is
Independently of each other, hydrogen atom, C₁~ C_FourAlkyl
Group, C₁~ C₈Alkoxyl group, halogen atom, halogen
Methylated group, nitro group, or substituted or unsubstituted amino
X represents a group¹And X^Two, X^TwoAnd X^Three, X^ThreeAnd X^Four, X^Five
And X⁶, X⁶And X⁷, X⁷And X⁸Is adjacent to them
Form a substituted or unsubstituted aromatic ring structure with carbon atoms
May be X⁹Is C₁~ C₆Alkyl group, C₁~ C₈
Alkoxy group, substituted or unsubstituted amino group, or halo
Represents a gen atom, m represents 0, or an integer of 1 to 4,
In formula (II), W represents a carbon atom or a nitrogen atom, and Z is
Represents a hydrogen atom or a group of formula (III), Y¹Is a hydrogen atom
Or represents a group of formula (IV) or formula (V),^TwoIs the expression (I
V) or a group of formula (V), X^TenIs C₁~ C₆Al
Kill group, C₁~ C₈Alkoxyl group, substituted or unsubstituted
Represents a mino group or a halogen atom, n is 0, or 1 to
Represents an integer of 4 and in the formula (III), R^TwoIs a hydrogen atom, C₁~
C₆Chain alkyl, C_Three~ C₆Cyclic alkyl, substituted or
Unsubstituted C₇~ C₂₀Aralkyl groups, substituted or unsubstituted phenyl
Lu group or C_Two~ C_TenRepresents an alkoxyalkyl group,
R in formula (IV)^ThreeAnd R^FourAre independent of each other
By the way, hydrogen atom, C₁~ C₈Chain alkyl, C_Three~ C₆
Cyclic alkyl, substituted or unsubstituted C₇~ C₂₀Aralkyl
Group, substituted or unsubstituted phenyl group, or C_Two~ C_TenAl
Represents a oxyalkyl group;^ThreeAnd R^FourAre each other
Pyrrolidino group, piperidino together with two adjacent nitrogen atoms
Group or a morpholino group may be formed, and X¹¹~ X¹⁴
Are, independently of each other, a hydrogen atom, C₁~ C_FourAl
Kill group, C₁~ C₈Represents an alkoxyl group and has the formula (V)
Medium, R^FiveAnd R⁶Are independent of each other,
Hydrogen atom, C ₁~ C₈Chain alkyl, C_Three~ C₆Ring
Rutile, substituted or unsubstituted C₇~ C₂₀Aralkyl group, or
Represents a substituted or unsubstituted phenyl group. In the multicolor heat-sensitive recording material of the present invention, the oxidative coloring type
Eiko dye is 8-diethylamino-11- (2-methoxy
Carbonylphenyl) benzo [a] xanthene, 8-di
Ethylamino-11- (2-ethoxycarbonylpheny
Ru) benzo [a] xanthene, 8-diethylamino-1
1- (2-butoxycarbonylphenyl) benzo [a]
It consists of at least one selected from xanthene.
Preferably, there is. Furthermore, the multicolor thermosensitive recording material of the present invention
In, the oxidant is a triarylmethyl compound.
Preferably. Furthermore, in the multicolor thermosensitive recording material of the present invention
Where the oxidizing agent is represented by the following general formula (VI):
It must consist of at least one selected from compound
Is preferred.

Embedded image [Wherein, in the formula (VI), X ¹⁵ represents a halogen atom, a substituted carbonyl group, a substituted sulfonyl group, a nitro group, or a cyano group, and X ^{16 to} X ¹⁸ are each independently a hydrogen atom or a halogen atom. , Substituted carbonyl group, substituted sulfonyl group, nitro group, cyano group, C ₁ -C ₆ chain alkyl, C
_{3 to} C ₆ cyclic alkyl, a substituted or unsubstituted C _{7 to} C ₂₀ aralkyl group, or a substituted or unsubstituted phenyl group. ]

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-sensitive recording material of the present invention has two or more heat-sensitive color forming layers formed on a support, and at least one of these heat-sensitive color forming layers contains an oxidative color-forming leuco dye. A coloring layer containing an oxidant capable of oxidizing the oxidative coloring leuco dye under heating to develop a color, and a photoreducing agent which is activated by light and exhibits a high reducing property. When this coloring layer is heated, the oxidative coloring type leuco dye is oxidized by an oxidizing agent and can develop a color. On the other hand, when this color-forming layer is irradiated with light, the photo-reducing agent is activated and exhibits a reducing property, and due to this reducing property, even if it is further heated after light-irradiating, the oxidation-coloring leuco dye is oxidized. Therefore, it does not develop color. That is, the color image formed on the thermosensitive coloring layer by heating and oxidization can be optically fixed.

[0007] By combining a thermosensitive coloring layer containing an oxidative coloring type leuco dye, an oxidizing agent and a photoreducing agent as a low temperature coloring layer and combining it with a high temperature coloring layer which develops at a higher temperature, the following multicolor coloring recording is possible. become. 1) Only the low-temperature color-developing layer is colored by heating and fixing it at a low temperature. 2) After photo-fixing, only the high temperature color developing layer is colored by heating at high temperature. 3) Under the conditions of 1), after the color development and fixing, the low temperature color development portion is further heated at a high temperature so that the mixed color of the high temperature layer and the low temperature layer is developed. Further, by controlling the applied densities during low temperature heating and high temperature heating to control the color density of each layer, the color hues of the layers can be mixed and the recording hue can be synergistically increased. Alternatively, the multicolor heat-sensitive recording material of the present invention has an advantage that the white paper portion does not develop color during photofixing, which is observed when a combination of a diazo component and a coupler component is used.

The oxidative coloring leuco dye used in the present invention is usually a colorless or light-colored compound, which is a compound which forms a chromophor by oxidation. Examples of such oxidative coloring leuco dyes include JP-B No. 2-14353, JP-A No. 62-198494, and U.S. Pat. No. 34.
45234, etc., aminotriarylmethane, aminoxanthene, aminothioxanthene, amino-9,10-dihydroacridine, aminophenoxazine, aminophenothiazine, aminodihydrophenazine, aminodiphenylmethane, leukoindamine, Aminohydrocinnamic acid, hydrazine, leucoin digoid dye, amino-2,3-dihydroanthraquinone, tetrahalo-p, p'-biphenol, 2-
Examples thereof include compounds such as (p-hydroxyphenyl) -4,5-diphenylimidazole and phenethylaniline, and alkoxyxanthene compounds. All of these compounds are compounds having a coloring structure by losing one or two hydrogen atoms. Among these, aminotriarylmethane, aminodiphenylmethane, aminoxanthene, aminophenothiazine, aminophenoxazine, and alkoxyxanthene are preferably used from the viewpoints of color developing sensitivity, fixability, and the like.

Specific examples of such oxidative coloring leuco dyes include aminophenothiazine and aminophenoxazine-based compounds such as 3,7-bis (dimethylamino) -10-benzoylphenothiazine and 3,7-bis (dimethyl). Amino) -10- (p-toluoyl) phenothiazine, 3,7-bis (dimethylamino) -10-pivaloylphenothiazine, 3,7-bis (diethylamino) -10-benzoylphenothiazine, 3,7-bis (diethylamino) ) -10- (p-toluoyl) phenoxazine and the like. Further, as the aminotriarylmethane and aminodiphenylmethane compounds, tris (4-dimethylaminophenyl) methane,
Bis (4-dimethylaminophenyl) methane, tris (4-diethylaminophenyl) methane, tris (4-
Dimethylamino-2-methylphenyl) methane, tris (4-diethylamino-2-methylphenyl) methane,
Bis (4-dimethylaminophenyl)-(4-diethylaminophenyl) methane, bis (4-diethylamino-)
2-Methylphenyl)-(4-diethylaminophenyl) methane, bis (4-dimethylamino-2-methylphenyl)-(4-dimethylaminophenyl) methane, bis (4-dimethylaminophenyl)-(2-methoxycarbonyl) Phenyl) methane, bis (4-dimethylaminophenyl)-(4-dimethylamino-2-methoxycarbonylphenyl) methane, (4-dimethylaminophenyl)-(4-diethylamino-2-methylphenyl)-
(4-Dimethylamino-2-methoxycarbonylphenyl) methane, bis (1-ethyl-2-methylindol-3-yl)-(2-methoxycarbonylphenyl) methane, and bis (1-methyl-2-phenylindole) -3-yl)-(2-methoxycarbonylphenyl)
Methane and the like can be given.

As another aminotriarylmethane-based compound and aminodiphenylmethane-based compound, (2-methyl-4-dimethylaminophenyl)-(1-ethyl-2)
-Methylindol-3-yl)-(2-methoxycarbonylphenyl) methane, (2-methyl-4-dimethylaminophenyl)-(1-ethyl-2-methylindol-3-yl)-(2-butoxycarbonyl Phenyl)
Methane, (2-methyl-4-diethylaminophenyl)
-(1-Ethyl-2-methylindol-3-yl)-
(2-methoxycarbonylphenyl) methane, (2-methoxy-4-dimethylaminophenyl)-(1-ethyl-2-methylindol-3-yl)-(2-methoxycarbonylphenyl) methane, (2-methyl- 4-Dimethylaminophenyl)-(1-methyl-2-phenylindol-3-yl)-(2-methoxycarbonylphenyl) methane, (2-methyl-4-dimethylaminophenyl)-(1-ethyl-2- Methylindol-3-yl)-(3-methoxycarbonyl-2-pyridyl) methane, (2-methyl-4-dimethylaminophenyl)-
(1-Ethyl-2-methylindol-3-yl)-
(3-butoxycarbonyl-2-pyridyl) methane,
(2-Methyl-4-diethylaminophenyl)-(1-
Ethyl-2-methylindol-3-yl)-(3-methoxycarbonyl-2-pyridyl) methane, (2-methyl-4-diethylaminophenyl)-(1-ethyl-2
-Methylindol-3-yl)-(3-ethoxycarbonyl-2-pyridyl) methane, (2-methoxy-4-
Dimethylaminophenyl)-(1-ethyl-2-methylindol-3-yl)-(3-methoxycarbonyl-
2-pyridyl) methane, (2-methyl-4-dimethylaminophenyl)-(1-methyl-2-phenylindol-3-yl)-(2-methoxycarbonyl-4-methoxyphenyl) methane, (2-methyl -4-dimethylaminophenyl)-(1-ethyl-2-methylindol-3-yl)-(2-methoxycarbonyl-3,4,
5,6-tetrabromophenyl) methane and the like can be mentioned.

Further, as the alkoxyxanthene compound, 3,6-dimethoxy-9- (2-methoxycarbonylphenyl) xanthene and 3,6-dimethoxy-9-
(2-ethoxycarbonylphenyl) xanthene, 3,
Examples thereof include 6-dimethoxy-9- (2-butoxycarbonylphenyl) xanthene and 3,6-dibutoxy-9- (2-butoxycarbonylphenyl) xanthene. Examples of the aminoxanthene compound include 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene and 8-diethylamino-
11- (2-phenoxycarbonylphenyl) -benzo [a] xanthene, 8-diethylamino-11- (2-
Ethoxycarbonylphenyl) -benzo [a] xanthene, 8-dibutylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene, 8-dibutylamino-11- (2-ethoxycarbonylphenyl)
-Benzo [a] xanthene, 8-dibutylamino-11
-(2-Butoxycarbonylphenyl) -benzo [a]
Xanthene etc. can be mentioned.

As another aminoxanthene compound, 3-dibutylamino-6-methyl-7-anilino-
9- (2-methoxycarbonylphenyl) xanthene,
3-diethylamino-6-methyl-7-anilino-9-
(2-methoxycarbonylphenyl) xanthene, 3-
Dibutylamino-6-methyl-7-anilino-9- (2
-Ethoxycarbonylphenyl) xanthene, 3- (N
-Isoamyl-N-ethylamino) -6-methyl-7-
Anilino-9- (2-methoxycarbonylphenyl) xanthene, 3-dibutylamino-7- (o-chloroanilino) -9- (2-methoxycarbonylphenyl) xanthene, 3-dimethylamino-7- (m-trifluoromethyl) Anilino) -9- (2-methoxycarbonylphenyl) xanthene, 3-pyrrolidino-6-methyl-7-
Anilino-9- (2-methoxycarbonylphenyl) xanthene, 3-piperidino-6-methyl-7-anilino-9- (2-methoxycarbonylphenyl) xanthene, 3-dimethylamino-7-dibenzylamino-9-
(2-methoxycarbonylphenyl) xanthene, 3-
Diethylamino-6-methyl-7-chloro-9- (2-
Methoxycarbonylphenyl) xanthene, 3-diethylamino-7-chloro-9- (2-methoxycarbonylphenyl) xanthene, 3-dibutylamino-6-methyl-7-chloro-9- (2-ethoxycarbonylphenyl) xanthene, 3 -Diethylamino-6,7-dimethyl-9- (2-methoxycarbonylphenyl) xanthene, 3- (N-ethyl-p-toluidino) -7-methyl-9- (2-methoxycarbonylphenyl) xanthene, 3-dibutyl Amino-6-methyl-7-anilino-
9- (2-methoxycarbonyl-4-methoxyphenyl) xanthene, 3-dibutylamino-6-methyl-7
-Anilino-9- (2-methoxycarbonyl-3,4,
5,6-Tetrachlorophenyl) xanthene, 3,6-
Examples thereof include bis (dimethylamino) -9- (2-methoxycarbonylphenyl) xanthene and 3,6-bis (diphenylamino) -9- (2-methoxycarbonylphenyl) xanthene. These oxidative coloring leuco dyes may be used alone or in combination of two or more. Of these, the compounds represented by the general formulas (I) and (II) can be preferably used because a multicolor thermosensitive recording material in which the uncolored portion is less discolored by sunlight, ultraviolet rays, or the like can be obtained. In particular, 8-diethylamino-11-
(2-Methoxycarbonylphenyl) -benzo [a] xanthene, 8-diethylamino-11- (2-ethoxycarbonylphenyl) -benzo [a] xanthene, 8-
Diethylamino-11- (2-butoxycarbonylphenyl) -benzo [a] xanthene shows almost no discoloration and can be used particularly preferably.

Examples of the oxidizing agent that can be used in the present invention include triarylmethyl compounds and quinone compounds substituted with electron withdrawing groups. Examples of the triarylmethyl compound include triphenylmethyl chloride, triphenylmethyl bromide and the like. The quinone compound substituted with an electron-withdrawing group is 2,
2,5-dibromo-1,4-benzoquinone-3,6-dicarboxylic acid-di-n-hexyl ester, 2,5-dichloro-1,4-benzoquinone-3,6-dicarboxylic acid-diisobutyl ester, etc. -Dihalogen-1,4-benzoquinone-3,6-dicarboxylic acid esters, 2-p
-Toluenesulfonyl-1,4-benzoquinone and other monosulfonylquinones, 2,5-dibenzoyl-1,4-
2-substituted quinones such as benzoquinone and 1,4-benzoquinone-2,5-dicarboxylic acid dicyclohexyl ester,
o-chloranil, chloranil, bromanil, 1,4-
4-substituted quinones such as ethyl benzoquinonetetracarboxylate, 2,5-di-p-toluenesulfonyl-1,4-benzoquinone-3,6-dicarboxylic acid diisobutyl ester, 2,5-dibutylsulfonyl-1,4-benzoquinone Disulfonylquinone dicarboxylic acid esters such as -3,6-dicarboxylic acid diethyl ester; monosulfonylquinone dicarboxylic acid diesters such as 2-p-toluenesulfonyl-1,4-benzoquinone-3,6-dicarboxylic acid dicyclohexyl ester; Can be of course,
It is not limited to these, and if necessary, one kind,
Alternatively, two or more kinds of compounds can be used in combination. Among these oxidizing agents, the triarylmethyl compound and the compound represented by the general formula (VI) are preferably used because a multicolor heat-sensitive recording material excellent in color separation can be obtained.

Examples of the photoreducing agent used in the present invention include quinone, disulfide, diazoanthrone, diazonium salt diazophenanthrone, aromatic azide, acyloin and aroma described in JP-A No. 50-139724. Compounds such as group ketones, aromatic carbazides, diazo sulfonates, 2H-benzimidazoles and compounds such as anthrone and phenazine can be used. Specific examples thereof include 1,4-naphthoquinone, p-quinone, phenanthrenequinone, bilenquinone, 1,2-benzanthraquinone, 1-naphthyl disulfide,
-Diazoanthrone, benzophenone, benzoin, benzoin isobutyl ether, 2,2-dimethyl-2H
-Benzimidazole, benzuanthrone, phenazine and the like. Of course, the photoreducing agent used in the present invention is not limited to these, and if necessary, one kind or two or more kinds of compounds can be used in combination.
In this case, utilizing the difference in the wavelength of photoactivation of each compound,
Each photoreducing agent can be activated with light of a different wavelength. The amount of the photoreducing agent used is not particularly limited.
It is preferable to mix and use it in a ratio of up to 2000% by weight, and more preferably 20 to 500% by weight.

The oxidative coloring type leuco dye, the oxidizing agent and the photoreducing agent used in the present invention are used as a uniform dispersion by solid-dispersing them together with a water-soluble polymer by a sand mill or the like. As the water-soluble polymer, various anions, nonions, cations or amphoteric water-soluble polymers are used. Among these, partially saponified polyvinyl alcohol has high emulsion stability and is preferably used. Further, modified polyvinyl alcohol (acetoacetyl group-modified, carboxyl group-modified, silicon-modified, etc.) can impart water resistance to the thermosensitive color developing layer, and is therefore preferably used for the application of the thermosensitive recording material of the present invention. The size of each dispersed component particle is preferably 0.3 μm to 10 μm.

In the thermosensitive coloring layer of the present invention, the oxidation coloring type leuco dye and the oxidizing agent are separated from the other coloring components to prevent discoloration of the uncolored portion (blank fog) and further improve the raw storability. Either one or both of the leuco dye and the oxidizing agent can be included in separate microcapsules. The photoreducing agent is preferably encapsulated in microcapsules in order to increase the efficiency of photoactivation. These microcapsules can be prepared by various known methods. Generally, a solution (oil-soluble) containing an oxidizing agent, a photoreducing agent or an oxidative coloring leuco dye as a main component as described above in an aqueous medium is used. It is prepared by a method of emulsifying and dispersing in an emulsion and forming a wall film composed of a polymer substance around the oily droplets. As the wall material of the microcapsules, polyurethane, polyurea, polyester, polycarbonate, urea-formaldehyde resin, melamine resin, polystyrene, styrene methacrylate copolymer,
Known microcapsule wall materials such as gelatin, polyvinylpyrrolidone, polyvinyl alcohol and the like can be mentioned. Also, two or more of these polymer materials can be used in combination.

The microcapsules having a wall film made of a polyurethane / polyurea resin contain a material for forming a capsule wall film such as an isocyanate compound alone, a polyvalent isocyanate and a polyol that reacts therewith, or an adduct of a polyvalent isocyanate and a polyol. , A core-forming substance to be encapsulated, and an emulsified dispersion of the core-forming substance in an aqueous medium in which a protective colloid substance such as polyvinyl alcohol is dissolved, and the liquid temperature is raised to form a polymer-forming reaction at the oil droplet interface. Manufactured by causing

Examples of polyvalent isocyanate compounds and adducts of polyvalent isocyanates and polyols used for preparing capsules include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate and 2,4-triene diisocyanate. Diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4 '
-Diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate,
Propylene-1,2-diisocyanate, butylene-
1,2-diisocyanate, cyclohexylene-1,2
-Diisocyanates, diisocyanates such as cyclohexylene-1,4-diisocyanate, 4,4 ', 4 "
-Triphenylmethane triisocyanate, toluene-
Triisocyanates such as 2,4,6-triisocyanate, 4,4′-dimethyldiphenylmethane-2,
Tetraisocyanates such as 2 ', 5,5'-tetraisocyanate, an adduct of hexamethylene diisocyanate and trimethylolpropane, an adduct of 2,4-tolylene diisocyanate and trimethylolpropane, xylylene diisocyanate and trimethylol Examples thereof include an adduct with propane, an isocyanate prepolymer such as an adduct of tolylene diisocyanate with hexanetriol, and a hexamethylene diisocyanate trimer (burette type, isocyanurate type).

Examples of the polyol compound used for preparing the microcapsules include ethylene glycol and
1,3-propanediol, 1,4-butanediol,
1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, propylene glycol, 2,3-dihydroxybutane, 1,2-dihydroxybutane, 1,3-dihydroxy Butane, 2,2-dimethyl-1,3-propanediol, 2,4-pentanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, 1,
4-cyclohexanedimethanol, dihydroxycyclohexane, diethylene glycol, 1,2,6-trihydroxyhexane, phenylethylene glycol, 1,
Aliphatic polyols such as 1,1-trimethylolpropane, hexanetriol, pentaerythritol and glycerin, aromatic compounds such as 1,4-bis (2-hydroxyethoxy) benzene and 1,3-bis (2-hydroxyethoxy) benzene Condensation product of polyhydric alcohol and alkylene oxide, p-xylylene glycol, m-xylylene glycol, α, α′-dihydroxy-p-diisopropylbenzene, 4,4′-dihydroxydiphenylmethane, 2- (p, p '-Dihydroxydiphenylmethyl) benzyl alcohol, 4,4'-isopropylidene diphenol, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide,
Examples thereof include ethylene oxide adduct of 4,4′-isopropylidenediphenol and propylene oxide adduct of 4,4′-isopropylidenediphenol.

Of course, the polyvalent isocyanate compound, the addition product of the polyvalent isocyanate and the polyol, and the polyol compound used for the preparation of the microcapsules are not limited to the above compounds, and if necessary, two or more of them may be used. It is also possible to use together. Among the polyvalent isocyanate compounds or the adducts of the polyvalent isocyanate compounds and the polyol compounds used in the present invention, it is particularly preferable to use one having three or more isocyanate groups in the molecule.

The microcapsules having a wall film made of an aminoaldehyde resin are obtained by emulsifying the core substance and then adding a wall film agent to the emulsion. Capsules having an aminoaldehyde resin membrane used in the present invention generally include urea, thiourea, alkyl urea, ethylene urea,
At least one amine such as acetoguanamine, benzoguanamine, melamine, guanidine, biuret, and cyanamide and at least one aldehyde such as formaldehyde, acetaldehyde, paraformaldehyde, glutaraldehyde, glyoxal, and furfural, or an initial product obtained by condensing them. It can be produced by an in-situ polymerization method using a condensate or the like. As an emulsifier (protective colloid agent) used for microencapsulation, various anions, nonions,
A cation or an amphoteric water-soluble polymer is used. Of these, partially saponified polyvinyl alcohol is preferably used because it has high emulsion stability. Further, modified polyvinyl alcohol (acetoacetyl group-modified, carboxyl group-modified, silicon-modified, etc.) can impart water resistance to the microcapsule wall film, and is therefore preferably used for the application of the heat-sensitive recording material of the present invention.

The microcapsule used in the present invention may contain a high boiling point solvent, if necessary. The high boiling point solvent is not particularly limited, and can be appropriately selected and used from various high boiling point hydrophobic media used in the field of pressure-sensitive copying paper. Such high-boiling solvents include, for example, tricresyl phosphate, phosphoric acid esters such as octyldiphenyl phosphate, dibutyl phthalate, phthalic acid esters such as dioctyl phthalate, carboxylic acid such as butyl oleate. Alkylated naphthalenes such as esters, various fatty acid amides, diethylene glycol dibenzoate, monoisopropyl naphthalene and diisopropyl naphthalene, 1-methyl-1-phenyl-1-tolylmethane, 1-methyl-1-phenyl-1-
Alkylated benzenes such as xylylmethane and 1-phenyl-1-tolylmethane, alkylated biphenyls such as isopropyl biphenyl, xenoxyalkanes such as o-phenylphenol glycidyl ether, acrylic acid esters such as trimethylolpropane triacrylate, Ester of polyhydric alcohol and unsaturated carboxylic acid,
It can be selected from chlorinated paraffin, kerosene and the like. Of course, these may be used alone or in combination of two or more.

The amount of the capsule wall membrane material to be used is also not particularly limited, but the proportion of the wall membrane material is 5 to 70% by weight, preferably 10 to the total weight of the microcapsules.
It is desirable to select it in the range of 50% by weight. The amount of the emulsifier used in preparing the microcapsules is not particularly limited, but generally, it may be adjusted and used in the range of 1 to 50% by weight, preferably 3 to 30% by weight, based on the wall membrane material. .

The microcapsules used in the present invention may optionally contain one or more kinds of ultraviolet absorbers, antioxidants, oil-soluble fluorescent dyes, release agents and the like.
In addition, at the time of microencapsulation, a tin compound, a polyamide compound, an epoxy compound, a polyamine compound, or the like can be used in combination as a reaction accelerator. When a polyamine compound is used for forming the microcapsule wall film, it is desirable to use an aliphatic polyamine compound from the viewpoint of light resistance.

The average particle size of the microcapsules used in the present invention is 0.1 to 5.0 μ in consideration of color development sensitivity.
It is preferably m, and more preferably 0.3 to 3.
It is adjusted to be in the range of about 0 μm.

The oxidative color-forming dye, oxidizing agent and photoreducing agent used in the present invention are dissolved in a high boiling non-aqueous medium and used as an emulsion together with a suitable emulsifier such as a water-soluble polymer such as polyvinyl alcohol. You can Examples of preferable high-boiling-point non-aqueous medium and emulsifier used in this case include those similar to those used when preparing the above-mentioned microcapsules. The average particle size of the emulsified particles is preferably 0.1 to 3 μm, more preferably 0.3 to 2.5 μm, in consideration of color development sensitivity.
Adjust so that the range is about m.

The oxidative color-forming leuco dye, oxidizing agent and photoreducing agent used in the present invention can be dissolved in a non-aqueous medium together with a suitable non-water-soluble resin such as an acrylic resin. Preferred non-aqueous media used in this case include xylene, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, methyl cellosolve, butyl cellosolve and the like.

In the present invention, in order to improve the photo-fixing property, other reducing agents can be added to the thermosensitive color developing layer in addition to the above-mentioned photo-reducing agent. Examples of these reducing agents include:
p-hydroquinone, 4-methoxy-1-naphthol, 4
-Methoxyphenol, 2-methoxyphenol, 4-
Hydroxydiphenyl ether, 4-methyl-4'-hydroxydiphenyl thioether, 2,5-di-ter
Examples thereof include t-butylhydroquinone and 2,5-di-tert-amylhydroquinone. Of course, the reducing agents that can be used are not limited to these, and if necessary, only one type or two or more types of compounds can be used in combination.

In the heat-sensitive recording material of the present invention, the heat-oxidative color-developing photo-fixing type heat-sensitive color developing layer containing an oxidative color-forming leuco dye, an oxidizing agent and a photoreducing agent may be one layer or two or more layers. When it has only one layer, it has a thermosensitive coloring layer of a coloring system different from this. Further, when the heat-oxidizing color-developing light fixing type heat-sensitive color forming layer is composed of two or more layers, it may have the other color-forming type heat-sensitive color forming. Such another color-forming layer can be selected from a combination of an electron-donating dye precursor and an electron-accepting compound used in a conventional heat-sensitive recording material, or a combination of a diazo compound and a coupling component. . Examples of electron-donating dye precursors used in such other color-forming layers include triaryl dyes, diphenylmethane dyes, thiazine dyes, spiro dyes, lactam dyes, fluorane dyes, and other conventionally known electron donors. A wide variety of chromogenic dyes can be used. Among the specific examples of the electron-donating color forming dye precursor,
As a dye that gives a black color, 3-pyrrolidino-6-
Methyl-7-anilinofluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3- (N-isoamyl-N-ethylamino) -7-
(O-chloroanilino) fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-2-tetrahydrofurfurylamino) -6-methyl -7- Anilino Fluoran,
3-Diethylamino-6-chloro-7-anilinofluorane, 3-di (n-butyl) amino-6-methyl-7-
Anilinofluorane, 3-di (n-amyl) amino-6
-Methyl-7-anilinofluorane, 3- (N-isoamyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3- (Nn-hexyl-N-ethylamino) -6 -Methyl-7-anilinofluorane, 3- [N
-(3-Ethoxypropyl) -N-ethylamino] -6
-Methyl-7-anilinofluorane, 3- [N- (3-
Ethoxypropyl) -N-methylamino] -6-methyl-7-anilinofluorane, 3-diethylamino-7-
(2-chloroanilino) fluorane, 3-di (n-butyl) amino-7- (2-chloroanilino) fluorane,
3-diethylamino-6-methyl-7-anilinofluorane, 3- (N-cyclohexyl-N-methylamino)
-6-methyl-7-anilinofluorane and the like can be mentioned.

Further, as dye precursors which give red, magenta, or orange coloration, 3,6-bis (diethylamino) fluorane-γ-anilinolactam, 3,6
-Bis (diethylamino) fluorane-γ- (p-nitroanilino) lactam, 3,6-bis (diethylamino) fluorane-γ- (o-chloroanilino) lactam, 3-dimethylamino-7-bromofluorane, 3-
Diethylaminofluoran, 3-diethylamino-6-
Methyl fluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-bromofluoran, 3-
Diethylamino-7,8-benzofluoran, 3-diethylamino-6,8-dimethylfluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7-tert-butylfluoran, 3-
(N-ethyl-N-tolylamino) -7-methylfluorane, 3- (N-ethyl-N-tolylamino) -7-ethylfluorane, 3- (N-ethyl-N-isobutylamino) -6-methyl -7-Chlorofluorane, 3- (N
-Ethyl-N-isoamylamino) -7,8-benzofluorane, 3-cyclohexylamino-6-chlorofluorane and the like can be mentioned.

Further, as a reddish purple or orange dye precursor, 3-di-n-butylamino-6-methyl-7-bromofluorane and 3-di-n-butylamino-7,8-benzofluorane are used. , 3-tolylamino-7-methylfluorane, 3-tolylamino-7-ethylfluorane, 2-
(N-Acetylanilino) -3-methyl-6-di-n-
Butylaminofluorane, 2- (N-propionylanilino) -3-methyl-6-di-n-butylaminofluorane, 2- (N-benzoylanilino) -3-methyl-
6-di-n-butylaminofluorane, 2- (N-carbobutoxyanilino) -3-methyl-6-di-n-butylaminofluorane, 2- (N-formylanilino)-
3-methyl-6-di-n-butylaminofluorane, 2
-(N-benzylanilino) -3-methyl-6-di-n
-Butylaminofluorane, 2- (N-allylanilino) -3-methyl-6-di-n-butylaminofluorane, 2- (N-methylanilino) -3-methyl-6-di-n-butylaminofluor Oran, 3,3'-bis (1-
n-Butyl-2-methylindol-3-yl) phthalide, 3,3′-bis (1-ethyl-2-methylindol-3-yl) phthalide, 3,3′-bis (1-n-octyl- 2-methylindol-3-yl) phthalide,
7- (N-ethyl-N-isoamylamino) -3-methyl-1-phenylspiro [(1,4-dihydrochromeno [2,3-c] pyrazole) -4,3'-phthalide],
7- (N-ethyl-N-isoamylamino) -3-methyl-1-p-methylphenylspiro [(1,4-dihydrochromeno [2,3-c] pyrazole) -4,3'-phthalide] , 7- (N-ethyl-Nn-hexylamino) -3-methyl-1-phenylspiro [(1,4-dihydrochromeno [2,3-c] pyrazole) -4,3 '
-Phthalide] and the like.

As the color-forming dye which gives blue color,
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2)
-Methylphenyl) -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (4-diethylaminophenyl) phthalide, 3 -(1-ethyl-2
-Methylindol-3-yl) -3- (2-methyl-
4-diethylaminophenyl) -4-azaphthalide, 3
-(1-Ethyl-2-methylindol-3-yl)-
3- (2-ethoxy-4-diethylaminophenyl)-
4-azaphthalide, 3- (1-ethyl-2-methylindol-3-yl) -3- (2-n-hexyloxy-
4-diethylaminophenyl) -4-azaphthalide, 3
-Diphenylamino-6-diphenylaminofluorane and the like can be mentioned.

The color-forming dye that gives a green color is 3
-(N-ethyl-Nn-hexylamino) -7-anilinofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4 -Azaphthalide, 3-
(N-ethyl-Np-tolylamino) -7- (N-phenyl-N-methylamino) fluorane, 3- [p-
(P-anilinoanilino) anilino] -6-methyl-7
-Chlorofluorane, 3,6-bis (dimethylamino)
Examples thereof include fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide.

As a dye giving a yellowish color, 3,
6-dimethoxyfluorane, 1- (4-n-dodecyloxy-3-methoxyphenyl) -2- (2-quinolyl)
Examples include ethylene. The above-mentioned electron-donating color forming dyes may be used alone or in combination of two or more.

As the electron-accepting compound, 4-tert
-Butylphenol, 4-acetylphenol, 4-t
ert-octylphenol, 4,4'-sec-butylidene diphenol, 4-phenylphenol, 4,
4'-dihydroxydiphenylmethane, 4,4'-isopropylidene diphenol, 4,4'-cyclohexylidene diphenol, 4,4'-dihydroxydiphenyl sulfide, 4,4'-thiobis (6-tert-butyl-3-) Methylphenol), 4,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate. , 4-hydroxybenzoic acid-sec-butyl, 4-hydroxybenzoic acid phenyl, 4-hydroxybenzoic acid benzyl, 4-hydroxybenzoic acid tolyl, 4-hydroxybenzoic acid chlorophenyl, 4,4'-dihydroxydiphenyl ether, , 4'-Dihydroxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone and other phenolic compounds, or benzoic acid, p-tert-butylbenzoic acid, trichlorobenzoic acid, terephthalic acid, salicylic acid, 3- Aromatic carboxylic acids such as tert-butylsalicylic acid, 3-isopropylsalicylic acid, 3-benzylsalicylic acid, 3- (α-methylbenzyl) salicylic acid, 3,5-di-tert-butylsalicylic acid, and these phenolic compounds, aromatic Salts of carboxylic acids with polyvalent metals such as zinc, magnesium, aluminum, calcium, 4,4'-bis (p-toluenesulfonylaminocarbonylamino)
Diphenylmethane, N- (p-toluenesulfonyl)-
Examples thereof include sulfonylurea compounds such as N'-phenylurea. These color-developing compounds may be used alone or in combination of two or more.

The diazo compound used in the heat-sensitive color forming layer by the combination of the diazo compound and the coupling component is
An aromatic compound having a photodegradable diazo group such as a diazonium salt, a diazosulfonate compound, a diazoamino compound, a quinonediazide compound. The diazonium salt is a compound represented by the general formula: Ar—N ₂ ⁺ .X ⁻ (wherein Ar represents an aromatic moiety, N ₂ ⁺ represents a diazonium group, and X ⁻ represents a counter anion). These have various maximum absorption wavelengths depending on the position and type of the substituent of the Ar moiety.

Specific examples of the diazonium compound include 4
-Dimethylaminobenzenediazonium, 4-diethylaminobenzenediazonium, 4-dipropylaminobenzenediazonium, 4-methylbenzylaminobenzenediazonium, 4-dibenzylaminobenzenediazonium, 4-ethylhydroxyethylaminobenzenediazonium, 4-diethylamino-2 -Methoxybenzenediazonium, 4-dimethylamino-3-methylbenzenediazonium, 4-benzoylamino-2,5-diethoxybenzenediazonium, 2,5-diethoxy-
4-morpholinobenzenediazonium, 4-morpholinobenzenediazonium, 2,5-dibutoxy-4-morpholinobenzenediazonium, 4-anilinobenzenediazonium, 4- (p-tolylthio) -2,5-diethoxybenzenediazonium, 4- (P-tolylthio)-
2,5-dibutoxybenzenediazonium, 4- (N,
N-dioctylcarbamoyl) benzenediazonium,
2-octadecyloxybenzenediazonium, 4-
(4-tert-octylphenoxy) benzenediazonium, 4- (2,4-di-tert-amylphenoxy) benzenediazonium, 2- (4-tert-octylphenoxy) benzenediazonium, 5-chloro-
Examples include 2- (4-tert-octylphenoxy) benzenediazonium, 2,5-bis-octadecyloxybenzenediazonium, 2,4-bis-octadecyloxybenzenediazonium, and 4- (N-octyltheuroylamino) benzenediazonium. be able to.

Specific examples of the counter anion of the diazonium salt include Cl ⁻ , 1/2 (ZnCl ₂ ) ⁻ , BF ₄ ⁻ , P.
F ₆ ⁻ , B (Ph) ₄ ⁻ , C _n F _{2n + 1} COO ⁻ (n is 3
Represents a _{~9), C m F 2m +} 1 SO 3 - (m represents an _{2~8), (C k F 2k} + 1 SO 2) 2 CH - represents the (k is 1 to 18), C _{1 F 21-1 OC 6 H 4 SO 3} - (1 5-10
Can be mentioned).

The diazosulfonate compound is a compound represented by the general formula: Ar-N ₂ -SO ₃ Y (wherein Ar represents an aromatic moiety and Y represents an alkali metal or ammonium).

Specific examples of the diazosulfonate compound include 2-methoxy, 2-phenoxy and 2-methoxy-4.
-Phenoxy, 2,4-dimethoxy, 2-methyl-4-
Methoxy, 2,4-dimethyl, 2,4,6-trimethyl, 2,4,6-trimethoxy, 2,4-dimethoxy-
5-chloro, 2-methoxy-5-nitro, 2-methoxy-5-acetamide, 2-methoxy-5-N, N-diethylsulfonamide, 2-methoxy-5-N-phenylcarbamyl, 3-methyl, 4-methyl, 4-methoxy,
4-ethoxy, 4-phenyl, 4-phenoxy, 4-acetamide, 4- (N-ethyl-N-benzylamino), 4- (N, N-dimethylamino), 4- (N, N)
-Diethylamino), 4- (N, N-diethylamino)
-3-chloro, 4- (N-ethylamino) -3-methyl, 4- (N, N-diethylamino) -2-methyl, 4
-(N-ethyl-N-β-hydroxyethylamino),
4-pyrrolidino-3-chloro, 4-pyrrolidino-3,5
-Dichlor, 4-morpholino, 4-morpholino-3-chlor, 4-morpholino-2-methoxy, 4-morpholino-2,5-diethoxy, 4-morpholino-2,5-dibutoxy, 4- (4'-tolyl Mercapto) -2,5-dibutoxy, 4- (4'-tolylmercapto) -2,5-
Diethoxy, 4- (4'-methoxybenzoylamino)
It is a potassium salt, a lithium salt and an ammonium salt of benzenediazosulfonic acid having each substituent other than sodium benzenediazosulfonate having a substituent such as -2,5-dibutoxy and 4-diphenylamino groups.

The diazoamino compound is a compound obtained by coupling the diazo group of the diazo compound with dicyandiamide, sarcosine, methyltaurine, N-ethylanthranic acid-5-sulphonic acid, monoethanolamine, diethanolamine, guanidine and the like.

The quinonediazide is structurally considered to be an inner salt type diazonium salt, and specific examples thereof include:
1,2-quinonediazide-4-sulfone sodium salt,
Sodium 1,2-naphthoquinonediazide-5-sulfonate, sodium 1,2-naphthoquinonediazide-4-sulfonate, 1,2-naphthoquinonediazide-5-sulfonate-p-cumylphenyl, 1,2-naphthoquinonediazide-4 -Sulfonic acid-p-cumylphenyl, 1,2
-Methyl naphthoquinonediazide-5-sulfonate, 1,
Ethyl 2-naphthoquinonediazide-5-sulfonate,
Examples thereof include 1,2-naphthoquinonediazide-5-sulfonic acid-dimethylamide and 1,2-naphthoquinonediazide-5-sulfonic acid ester of novolak resin.

The coupling component reacts with the diazo compound to form an azo dye. For example, a typical coupler that produces a yellow dye is one in which a methylene group is activated by an adjacent carbonyl group and has the general formula R
COCH ₂ CO-R '(wherein R is an alkyl group, an aryl group, R' represents an aromatic amine) is a compound represented by. Examples of magenta couplers are 1) cyanoacetyl derivatives of cyclic compounds, or 2) heterocyclic compounds having an active methylene or other coupling moiety in the heterocycle, such as pyrazolone compounds and indazolone compounds. There is. Examples of cyan couplers include phenols and naphthols. Specific examples of these coupling components (couplers) include 4- (p-toluenesulfonylamino) -ω-benzoylacetanilide, α-benzoyl-o-methoxyacetanilide,
4-pyrazolic acid, 2-cyanoacetyl-coumarone, 1-
(2,4,6-Trichlorophenyl) -3-p-nitroamino-2-pyrazolone-5-one, resorcin, phloroglucin, 2,3-dihydroxynaphthalene, 2,6
-Dibromo-1,5-dihydroxy-naphthalene, N-
(O-acetamidophenethyl) -1-hydroxy-2
-Naphthamide and the like can be mentioned. These couplers may be used alone or in combination of two or more. Each of the electron-donating dye precursor, the electron-accepting compound, the diazo compound, and the coupling component can be used as a solid dispersion together with a water-soluble polymer by a sand mill or the like, or can be included in a microcapsule.

In the present invention, as the adhesive contained in the thermosensitive color developing layer, any of water-soluble resin, water-dispersible resin and water-insoluble resin can be used. For example, polyvinyl alcohol, starch, modified starch, gum arabic, gelatin, casein, chitosan, methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polyacrylic acid salt, polyacrylic amide,
Water-soluble resins such as polyester resin, styrene-acrylic acid ester copolymer resin, styrene-maleic anhydride copolymer resin, methyl vinyl ether-maleic anhydride copolymer resin, isopropylene-maleic anhydride copolymer resin, and polyacetic acid. Non-water-soluble resins such as vinyl, polyacrylic acid ester, polymethacrylic acid ester, polyurethane, polyvinyl chloride, polyethylene butadiene and polystyrene butadiene can be mentioned. Among them, the non-water-soluble resin is used as an emulsified dispersion in an aqueous medium. Alternatively, these water-insoluble resins can be used by dissolving them in a non-aqueous medium. These adhesives may be used alone or in combination of two or more.

However, when the above-mentioned adhesive is mixed with each dispersion liquid or solution of the oxidative coloring type leuco dye component and the oxidizing agent and the photo-reducing agent, the mixed liquid develops color, aggregates, or has a high viscosity. It is also necessary that the formed heat-sensitive recording layer film be tough and have no heat reducing effect. The blending amount of the adhesive in the thermosensitive coloring layer is preferably 5 to 80% by weight based on the total solid content of the thermosensitive coloring layer. If it is less than 5% by weight, the coating strength may be insufficient, and if it exceeds 80% by weight, the sensitivity may be lowered.

Further, in order to improve the water resistance of the thermosensitive coloring layer, a crosslinking agent for curing the resin can be used. For example, aldehyde compounds such as glyoxal, polyamine compounds such as polyethyleneimine, epoxy compounds, polyamide resins, melamine resins, dimethylolurea compounds, aziridine compounds, blocked isocyanate compounds, and ammonium persulfate and ferric chloride, and magnesium chloride. Inorganic compounds such as sodium tetraborate, potassium tetraborate, etc. or boric acid, boric acid triesters, boron-based polymers, etc. are used in the range of 1 to 10% by weight based on the total solid content of the thermosensitive coloring layer. preferable.

In the present invention, a fine particle pigment having a high whiteness and an average particle diameter of 10 μm or less can be used in order to improve the whiteness of the thermosensitive coloring layer and the uniformity of the image.
For example, calcium carbonate, magnesium carbonate, kaolin, clay, talc, calcined clay, silica, diatomaceous earth, synthetic aluminum silicate, zinc oxide, titanium oxide,
Aluminum hydroxide, barium sulfate, inorganic pigments such as surface-treated calcium carbonate and silica, and urea-
Formalin resin, styrene-methacrylic acid copolymer resin,
Organic pigments such as polystyrene resin can be used. The amount of the pigment blended is preferably 50% by weight or less based on the total solid content of the thermosensitive coloring layer in order not to reduce the coloring density.

In the present invention, various thermofusible substances can be contained in the thermosensitive coloring layer. Examples of the heat-fusible substance include stearic acid amide, ethylenebisstearic acid amide, oleic acid amide, palmitic acid amide, palm fatty acid amide, behenic acid amide and other fatty acid amides, zinc stearate, calcium stearate, polyethylene wax. , Carnauba wax, paraffin wax, ester wax and other waxes (or lubricants), terephthalic acid dimethyl ester, terephthalic acid dibutyl ester, terephthalic acid dibenzyl ester, isophthalic acid dibutyl ester, 1-hydroxynaphthoic acid phenyl ester, 1,2- Bis (3-methylphenoxy) ethane, 1,2-diphenoxyethane, 1-phenoxy-2- (4-methylphenoxy) ethane, diphenyl carbonate, p-benzylbiphenyl, 2,2'-methylenebis 4-methyl -6-t-butylphenol),
4,4'-butylidene bis (6-t-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4)
-Hydroxy-5-t-butylphenyl) butane, 2,
Such as 2'-methylenebis (4-ethyl-6-t-butylphenol), 2,4-di-t-butyl-3-methylphenol, 4,4'-thiobis (3-methyl-6-t-butylphenol) Hindered phenols, 2-
There are sensitizers such as (2'-hydroxy-5'-methylphenyl) -benzotriazole and 2-hydroxy-4-benzyloxybenzophenone, antioxidants, and ultraviolet absorbers.

Generally, the heat-fusible substance is preferably contained in the heat-sensitive color forming layer in a proportion of 400% by weight or less based on the oxidation color-forming leuco dye. Further, in order to improve the wetting of the heat-sensitive color developing layer coating and eliminate repelling, the heat-sensitive color developing layer may contain a wettability improving agent such as acetylene glycol or dialkyl sulfosuccinate, and a pigment dispersant or a defoaming agent. , A fluorescent dye and the like can be added as required.

The support used in the multicolor heat-sensitive recording material of the present invention comprises a polyolefin resin on both sides of a core material formed by heat-kneading a polyolefin resin and a white inorganic pigment, extruding from a die and stretching in the machine direction. A synthetic paper produced by laminating one to two layers of a resin and a white inorganic pigment on one side, and making it translucent or opaque by stretching in the transverse direction, and polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, Polyvinyl chloride, polystyrene,
Or a film obtained by biaxially stretching a thermoplastic resin such as polyester alone or a mixture thereof, extruded from a die and biaxially stretched, an opaque film, a non-woven fabric, and a fine paper biaxially stretched by mixing a white inorganic pigment with these resins. (Acid paper, neutral paper), medium quality paper, recycled paper, coated paper, etc. When a support made of pulp fibers is used, in order to improve the uniformity of the image, a coating layer (undercoat layer) may be provided on the support in advance, and then a thermosensitive coloring layer may be coated thereon. preferable. Further, a protective layer may be provided on the thermosensitive coloring layer to improve sticking to the thermal head.

The coating amount of the thermosensitive coloring layer is generally 3 to 15 g / m ² in order to improve the coloring sensitivity and the coloring density.
It is preferred that The coating method is air knife method, Mayer bar method, blade method, reverse roll method,
Conventional methods used by those skilled in the art such as a slit die method, a multi-slide method, and a curtain coating method can be used. In addition, the surface of the thermosensitive coloring layer is subjected to a smoothing treatment using a super calender, a gloss calender, a machine calender, or the like, so that the surface properties can be increased, and the recording density and sensitivity can be improved. Also, on the opposite side of the recording layer of the support, a so-called tacking process such as a release labeling process in which a release paper is provided via an adhesive layer and a delayed tacking process in which an adhesive layer which exhibits adhesiveness by heating is provided. it can. In addition, this back side should be used as magnetic recording paper, thermal transfer paper, inkjet paper, xerography paper, carbonless paper, and electrostatic recording paper to make it possible to record on both sides. Can be. Of course, a double-sided heat-sensitive recording material can also be used. As a light source for photolysis when the heat-sensitive recording material of the present invention is optically fixed, various light sources which emit light of a desired wavelength can be used. For example, various fluorescent lamps, xenon lamps, xenon flash lamps, mercury lamps, photographic flashes, strobes and the like can be mentioned.

[0052]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these. Unless otherwise specified, "part" and "%"
Indicates "part by weight" and "% by weight", respectively.

Example 1 (1) Preparation of high temperature color thermosensitive recording layer liquid [Preparation of microcapsule dispersion containing electron donating dye precursor] 2- (4-dodecyloxy-3) as electron donating dye precursor 3 parts of -methoxystyryl) quinoline was dissolved in 20 parts of ethyl acetate, and to this solution was added 20 parts of a high boiling oil (trade name: KMC-113 manufactured by Kureha Chemical Co., Ltd.). Further, as a capsule wall material, trimethylolpropane and xylylene diisocyanate are mixed in a ratio of 1: 3.
Additive (Takeda Pharmaceutical Co., Ltd., Trademark: Takenate D-110)
N) 15 parts were added and mixed uniformly, and this mixed solution was adjusted to 8%.
Polyvinyl alcohol of Japan Synthetic Chemical Industry, trademark:
54 parts of an aqueous solution of Gohsenol GM-14L) was gradually added, and the mixture was emulsified and dispersed at a rotation speed of 10,000 rpm using a homogenizer. Next, 100 parts of water was added to this emulsified dispersion for homogenization. Next, while stirring this emulsion dispersion, the temperature was raised to 60 ° C. and a curing reaction was carried out for 3 hours to obtain a dispersion of the title microcapsules having an average particle diameter of 1.2 μm. [Electron-accepting compound dispersion] 4% of 4,4'-isopropylidenediphenol as an electron-accepting compound
Polyvinyl alcohol of Japan Synthetic Chemical Industry, trademark:
Gosenol GH-17) aqueous solution was added and dispersed using a ball mill for 24 hours so that the average particle size was 1.2 μm to obtain a dispersion. [Preparation of coating liquid] The above-mentioned microcapsule dispersion containing an electron-donating dye precursor, the above-mentioned electron-accepting compound dispersion, and 5% polyvinyl alcohol (manufactured by Japan Synthetic Chemical Industry, trademark: Gohsenol NH- 17) An aqueous solution was mixed so that the weight ratio after drying was 20:40:40 to prepare a high temperature color thermosensitive recording layer liquid.

(2) Preparation of low temperature color thermosensitive recording layer liquid [Preparation of microcapsule dispersion containing oxidative coloring leuco dye] 8-Diethylamino-11- (2-methoxycarbonylphenyl) -as oxidative coloring leuco dye
2 parts of benzo [a] xanthene was dissolved in 20 parts of ethyl acetate, and a high boiling oil (trade name: K, manufactured by Kureha Chemical Co., Ltd.) was added to this solution.
20 parts of MC-113) were added. Furthermore, as a capsule wall material, 15 parts of a 1: 3 adduct of trimethylolpropane and xylylene diisocyanate (Takenate D-110N, manufactured by Takeda Pharmaceutical Co., Ltd.) was added,
Mix evenly. This mixed solution was mixed with 8% polyvinyl alcohol (trade name: Gohsenol GM-, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).
14 L) 54 parts of an aqueous solution was gradually added, and the mixture was emulsified and dispersed at a rotation speed of 10,000 rpm using a homogenizer, and then 100 parts of water was added to homogenize it. While stirring this emulsion dispersion, the temperature was raised to 60 ° C. and curing reaction was carried out for 3 hours to obtain a dispersion of microcapsules having an average particle size of 1.1 μm. [Oxidizing agent dispersion] 4 parts of chloranil 30 parts as an oxidizing agent
Polyvinyl alcohol of Japan Synthetic Chemical Industry, trademark:
Gosenol GH-17) aqueous solution was added and dispersed using a ball mill for 24 hours so that the average particle size was 1.2 μm to obtain a dispersion. [Photoreducing agent emulsion dispersion] 3 parts of 1,4-naphthoquinone were dissolved in 10 parts of tricresyl phosphate, and this solution was added with 8% of a sulfo group-modified polyvinyl alcohol (trade name: Gocelan L-3266, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). After adding to 50 parts of the aqueous solution and using a homogenizer to emulsify and disperse at a rotation speed of 10000 rpm, 100 parts of water was added and homogenized to obtain an emulsified dispersion having an average particle size of 1.0 μm. [Preparation of coating liquid] Microcapsule dispersion containing the above-mentioned oxidative coloring leuco dye, oxidizer dispersion, photoreducing agent emulsion dispersion, and 5% polyvinyl alcohol (trade name: Gohsenol NH manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) -17) The aqueous solution was mixed so that the weight ratio after drying was 40: 40: 15: 5 to prepare a low temperature color thermosensitive recording layer liquid.

(3) Preparation of intermediate layer liquid 15 parts of a 10% aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry, trade name: Gohsenol GH-17) was added to styrene butadiene latex (manufactured by Nippon Zeon Co., trade name: PT).
3 parts by weight of a 15% emulsion of 1004) was added and mixed uniformly to prepare an intermediate layer liquid. (4) Preparation of protective layer liquid Polyvinyl alcohol (Nippon Gosei Kagaku Kogyo; trademark: Gohsenol NH-17) in a 6% aqueous solution 100 g, zinc stearate 21% dispersion liquid (Chukyo Yushi Co., Ltd., trademark: Hydrin Z-7) ) 10 g was added to prepare a protective layer solution. (5) Preparation of thermosensitive recording material On a commercially available polyethylene terephthalate film having a thickness of 75 μm (trade name: Lumirror E manufactured by Toray), a high temperature color thermosensitive recording layer solution prepared in advance from the support side using a Meyer bar, The intermediate layer liquid, the low-temperature color thermosensitive recording layer liquid, and the protective layer liquid each had a dry weight of 6 g / m ² , 2 g / m ² , 7 g /
A thermal recording material was prepared by coating so as to have m ² , 2 g / m ² .

Example 2 A thermal recording material was prepared in the same manner as in Example 1. However,
Instead of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1,
3,7-bis (dimethylamino) -10-benzoylphenothiazine was used.

Example 3 A thermal recording material was prepared in the same manner as in Example 1. However,
Instead of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1, (2-methyl-4-diethylaminophenyl)-( 1-
Ethyl-2-methylindol-3-yl)-(3-methoxycarbonyl-2-pyridyl) methane was used.

Example 4 A thermal recording material was prepared in the same manner as in Example 1. However,
Bis (1-ethyl-2-methylindole-3) was used in place of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1. -Ill)-
(2-Methoxycarbonylphenyl) methane was used.

Example 5 A thermal recording material was prepared in the same manner as in Example 1. However,
Bis (4-diethylamino-2-methylphenyl) -instead of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1. (4
-Diethylaminophenyl) methane was used.

Example 6 A thermal recording material was prepared in the same manner as in Example 1. However,
In place of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1, 3
-Dibutylamino-6-methyl-7-anilino-9-
(2-Methoxycarbonylphenyl) methane was used.

Example 7 A thermal recording material was prepared in the same manner as in Example 1. However,
Instead of 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene used as the oxidative coloring leuco dye for the low temperature coloring layer in Example 1, 3,6-dimethoxy-9- (2-ethoxy). Carbonylphenyl) xanthene was used, and 8-diethylaminobenzo [a] fluorane was used in place of 2- (4-dodecyloxy-3-methoxystyryl) quinoline used as a leuco dye for the high temperature coloring layer.

Example 8 A thermal recording material was prepared in the same manner as in Example 1. However, triphenylmethyl chloride was used in place of chloranil used as the oxidizing agent for the low temperature color forming layer in Example 1.

Example 9 A thermosensitive recording material was prepared in the same manner as in Example 1. However, benzophenone was used in place of 1,4-naphthoquinone used as the photoreducing agent for the low temperature color forming layer in Example 1.

Comparative Example 1 A thermal recording material was prepared in the same manner as in Example 1. However,
In the low temperature color thermosensitive color developing layer of Example 1, 2,5-diethoxy- (p -Tolylthio) benzenediazonium hexafluorophosphate was used, the coupler 4-pyrazolic acid was used in place of the 1,4-naphthoquinone used as the photoreducing agent, and no oxidizing agent was used.

Comparative Example 2 A thermal recording material was prepared in the same manner as in Example 1. However,
In the low temperature color thermosensitive color developing layer of Example 1, 8-diethylaminobenzo as an electron donating dye precursor was used instead of the oxidation color forming leuco dye 8-diethylamino-11- (2-methoxycarbonylphenyl) -benzo [a] xanthene. [A] Fluoran was used, zinc 3,5-bis (α-methylbenzyl) salicylate was used as an electron accepting compound instead of the oxidant chloranil, and no oxidant was used.

Tests The thermal recording materials obtained in Examples 1 to 9 and Comparative Examples 1 to 2 were commercial thermosensitive facsimiles H modified for testing.
Using IFAX-45, low-temperature color development was performed by solid printing of 128 lines under the conditions of 1 line recording time of 5 msec, sub-scanning line density of 8 lines / mm, and applied energy of 1.0 mJ per dot. Next, this color-developing surface is set to a center wavelength of 420
The image is fixed by exposing it to a UV lamp with an output of 40 nm and a power of 40 W for 20 seconds, then recording time for one line is 5 msec, sub-scanning linear density is 8 lines / mm, and the applied energy per dot is 2.0 m.
Under the conditions of J, solid printing of 128 lines was performed so that the high temperature printed portion partially overlaps the low temperature colored portion. A print part with only high-temperature color development and a print part with mixed color of high-temperature color development and low-temperature color development were obtained. The color tone is shown in Table 1.

(Hue expression property) With respect to the low temperature color development part, the high temperature color development part and the color mixture color development part thus obtained, the condition of hue development was visually observed and evaluated according to the following criteria. Shown in 1. ◯: Three different hues can be developed in the low temperature coloring portion, the high temperature coloring portion, and the color mixing portion. X: Only two or less hues can be developed in the low-temperature color development part, the high-temperature color development part, and the color mixture part.

(Stain) With respect to the uncolored portion (white paper portion) of the heat-sensitive recording material after the above color fixing, the whiteness of each was measured using a Hunter whiteness meter (D type, manufactured by Toyo Seiki Co., Ltd.). The results thus obtained are shown in Table 1. When the whiteness after light fixing is 85% or more, there is no practical problem. (Light resistance) The heat-sensitive recording material after the above color fixing was exposed to sunlight 2
After standing for 4 hours, the whiteness of each uncolored portion (white paper portion) was measured using a Hunter whiteness meter. Table 1 shows the results. The whiteness after the light resistance test is
If possible, 80% or more is desirable, and 85% or more is sufficient.

[0069]

[Table 1]

Example 10 (Full-color thermosensitive recording material) (1) Preparation of high-temperature color-developing (yellow) thermosensitive recording layer liquid [Preparation of electron-donating dye precursor dispersion liquid] 30 parts of 3,6-di-methoxyfluorane 4% polyvinyl alcohol (Nippon Gosei Kagaku Kogyo, trademark: Gohsenol GH-1
7) The mixture was poured into an aqueous solution and dispersed using a ball mill for 24 hours so that the average particle diameter was 1.2 μm, to obtain a dispersion liquid. [Electron-accepting compound dispersion] 30 parts of 4,4'-isopropylidenediphenol was added to 4% of polyvinyl alcohol (trade name: Gohsenol GH-1 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).
7) The mixture was poured into an aqueous solution and dispersed using a ball mill for 24 hours so that the average particle diameter was 1.2 μm, to obtain a dispersion liquid. [Preparation of coating liquid] A dispersion liquid of the electron-donating dye precursor, a dispersion liquid of the electron-accepting compound, and a 5% polyvinyl alcohol (manufactured by Japan Synthetic Chemical Industry, trademark: Gohsenol NH-17) aqueous solution, The weight ratio after drying is 20:
The mixture was mixed at 40:40 to prepare a high temperature color thermosensitive recording layer liquid.

(2) Preparation of Medium-Temperature Coloring (Magenta) Thermosensitive Recording Layer Liquid [Preparation of Microcapsule Dispersion Liquid Containing Oxidative Coloring Type Leuco Dye] 8-Diethylamino-11- (2-methoxycarbonyl) as oxidative coloring leuco dye Phenyl)-
4 parts of benzo [a] xanthene was dissolved in 20 parts of methylene chloride, and 20 parts of tricresyl phosphate was added to this solution. Further, as a capsule wall material, trimethylolpropane and xylylene diisocyanate are mixed in a ratio of 1: 3.
Additive (Takeda Pharmaceutical Co., Ltd., Trademark: Takenate D-110)
N) 15 parts were added and mixed uniformly, and this mixed solution was adjusted to 8%.
Polyvinyl alcohol of Japan Synthetic Chemical Industry, trademark:
Gosenol GM-14L) aqueous solution (54 parts) was gradually added, and the mixture was emulsified and dispersed at a rotation speed of 10,000 rpm using a homogenizer, and then 100 parts of water was added to homogenize. Next, while stirring this emulsion dispersion, the temperature was raised to 60 ° C. and curing reaction was carried out for 3 hours to obtain a dispersion of microcapsules having an average particle diameter of 1.2 μm. [Preparation of Microcapsule Dispersion Liquid Containing Oxidizing Agent] 1 part of chloranil as an oxidizing agent was dissolved in 50 parts of tricresyl phosphate. Furthermore, as a capsule wall material, a 1: 3 addition product of trimethylolpropane and xylylene diisocyanate (trade name: Takenate D manufactured by Takeda Pharmaceutical Co., Ltd.)
-110N) 15 parts were added and mixed uniformly, and this mixture was gradually added to 100 parts of an 8% polyvinyl alcohol (Nippon Gosei Kagaku Kogyo, trademark: Gohsenol GM-14L) aqueous solution, and a homogenizer was used. 100 rpm
After emulsifying and dispersing at 00 rpm, 100 parts of water was added to homogenize. Then, while stirring this emulsion dispersion,
The temperature is raised to 0 ° C., the curing reaction is performed for 3 hours, and the average particle size is 1.
A dispersion of 2 μm microcapsules was prepared. [Preparation of microcapsule dispersion containing photoreducing agent]
As a photoreducing agent, 4 parts of 1,4-naphthoquinone was dissolved in 25 parts of methylene chloride, and then 10 parts of tricresyl phosphate was added to this solution. Furthermore, 5 parts of a 1: 3 adduct of trimethylolpropane and xylylene diisocyanate (trade name: Takenate D-110N, manufactured by Takeda Pharmaceutical Co., Ltd.) was added to this as a capsule wall material, and the mixture was mixed uniformly to obtain a mixed solution. Was gradually added to 35 parts of an 8% aqueous solution of polyvinyl alcohol (trade name: Gohsenol GM-14L manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the number of revolutions was 100 using a homogenizer.
After emulsifying and dispersing at 00 rpm, 100 parts of water was added to homogenize. Then, while stirring this emulsion dispersion,
The temperature is raised to 0 ° C, the curing reaction is performed for 3 hours, and the average particle size is 1.0.
A dispersion of micron microcapsules was prepared. [Preparation of coating liquid] Microcapsule dispersion containing the above-mentioned oxidative coloring leuco dye, microcapsule dispersion containing an oxidizing agent, microcapsule dispersion containing a photoreducing agent and 5% polyvinyl alcohol Chemical industry, trademark: Gohsenol NH-17) aqueous solution,
After drying, the mixture was mixed so that the weight ratio was 40: 15: 30: 15 to prepare a medium-temperature color thermosensitive recording layer liquid.

(3) Preparation of low temperature color development (cyan) thermosensitive recording layer liquid [Preparation of microcapsule dispersion containing oxidative coloring leuco dye] Bis (4-diethylamino-2-methylphenyl) as oxidative coloring leuco dye 4 parts of-(4-diethylaminophenyl) methane was dissolved in 20 parts of methylene chloride, and 20 parts of tricresyl phosphate was added to this solution. Further, as a capsule wall material, trimethylolpropane and xylylene diisocyanate are mixed in a ratio of 1: 3.
Additive (Takeda Pharmaceutical Co., Ltd., Trademark: Takenate D-110)
N) 15 parts were added and mixed uniformly, and this mixed solution was adjusted to 8%.
Polyvinyl alcohol of Japan Synthetic Chemical Industry, trademark:
Gosenol GM-14L) aqueous solution (54 parts) was gradually added, and the mixture was emulsified and dispersed at a rotation speed of 10,000 rpm using a homogenizer, and then 100 parts of water was added to homogenize. Next, while stirring this emulsion dispersion, the temperature was raised to 60 ° C. and a curing reaction was carried out for 3 hours to prepare a dispersion of microcapsules having an average particle size of 1.1 μm. [Preparation of Microcapsule Dispersion Liquid Containing Oxidizing Agent] 1 part of chloranil as an oxidizing agent was dissolved in 50 parts of tricresyl phosphate. Furthermore, as a capsule wall material, a 1: 3 addition product of trimethylolpropane and xylylene diisocyanate (trade name: Takenate D manufactured by Takeda Pharmaceutical Co., Ltd.)
-110N) 15 parts were added and mixed uniformly, and this mixture was gradually added to 100 parts of an 8% polyvinyl alcohol (Nippon Gosei Kagaku Kogyo, trademark: Gohsenol GM-14L) aqueous solution, and a homogenizer was used. 100 rpm
After emulsifying and dispersing at 00 rpm, 100 parts of water was added to homogenize. Next, while stirring this emulsion dispersion, 60
The temperature is raised to ℃ and the curing reaction is performed for 3 hours, and the average particle size is 1.2.
A dispersion of micron microcapsules was prepared. [Preparation of microcapsule dispersion containing photoreducing agent]
As a photoreducing agent, 4 parts of 1,4-naphthoquinone was dissolved in 25 parts of methylene chloride, and tricresyl phosphate 10 was added to the solution.
Parts were added. Furthermore, as a capsule wall material,
5 parts of 1: 3 adduct of trimethylolpropane and xylylene diisocyanate (Takeda Yakuhin Kogyo, trade name: Takenate D-110N) was added and mixed uniformly, and this mixture was mixed with 8% polyvinyl alcohol (Nippon Gosei Chemical Industry, Trademark: Gohsenol GM-14L) was gradually added to 35 parts of an aqueous solution and a homogenizer was used to rotate at 1000 rpm.
After emulsifying and dispersing at 0 rpm, 100 parts of water was added to homogenize. Next, while stirring the emulsion dispersion, 60
The temperature is raised to ℃ and the curing reaction is performed for 3 hours, and the average particle size is 1.0μ.
A dispersion of m microcapsules was prepared. [Preparation of coating liquid] Microcapsule dispersion containing the above-mentioned oxidative coloring leuco dye, microcapsule dispersion containing an oxidizing agent, microcapsule dispersion containing a photoreducing agent, and 5% polyvinyl alcohol (Japan Synthetic Chemical Industry Co., Ltd., trade name: Gohsenol NH-17) aqueous solution was mixed so that the weight ratio after drying was 30: 40: 10: 20 to prepare a low temperature color thermosensitive recording layer liquid.

(4) Preparation of Intermediate Layer Liquid 15 parts of a 10% aqueous solution of polyvinyl alcohol (Nippon Gosei Kagaku Kogyo; trademark: Gohsenol GH-17) was added to styrene butadiene latex (Nippon Zeon, trademark: PT1).
3 parts by weight of a 15% aqueous dispersion of 004) was added and mixed uniformly to prepare an intermediate layer liquid. (5) Preparation of protective layer liquid Polyvinyl alcohol (Nippon Gosei Kagaku Kogyo, trademark: Gohsenol NH-17) 6% aqueous solution 100 g, zinc stearate 21% dispersion (Chukyo Yushi, trademark: Hydrin Z-7) 10 g Was added to prepare a protective layer solution. (6) Preparation of heat-sensitive recording material A commercially available 75 μm-thick polyethylene terephthalate film (trade name: Lumirror E manufactured by Toray Co., Ltd.) was used on a support, using a Mayer bar, in order from the support surface to the yellow heat-sensitive recording layer liquid, the intermediate layer. Liquid, magenta thermosensitive recording layer liquid, intermediate layer liquid,
The cyan thermosensitive recording layer liquid and the protective layer liquid each had a dry weight of 6 g / m ² , 2 g / m ² , 8 g / m ² , 2 g / m ² , 7
A thermal recording material was prepared by coating so as to have g / m ² and 2 g / m ² .

Test For the heat-sensitive recording material obtained by the above operation, using a commercially available heat-sensitive facsimile HIFAX-45 modified for the test, 1 line recording time 5 msec, sub-scanning linear density 8 lines / mm, application per dot 128 lines were printed under the condition of energy of 0.8 mJ, and color development was performed at low temperature heating. After this low-temperature printing, the center wavelength of this coloring surface is 420n
The image was fixed by exposing it to an ultraviolet lamp of m and an output of 40 W for 20 seconds. Next, 1 line recording time 5 msec, sub-scanning line density 8 lines / mm, applied energy per dot 1.6 mJ
By printing 128 lines under the conditions described above, color development was performed at medium temperature heating. After this printing, the surface has a center wavelength of 420n
The image was fixed by exposing it to an ultraviolet lamp of m and an output of 40 W for 80 seconds. Next, 1 line recording time 5 msec, sub-scanning line density 8 lines / mm, applied energy per dot 2.4 mJ
By printing 128 lines under the conditions described above, color development was performed under high temperature heating. Cyan for low-temperature coloring, magenta for medium-temperature coloring, yellow for high-temperature coloring, blue for areas where low-temperature coloring and medium-temperature coloring overlap, red for areas where middle-temperature coloring and high-temperature coloring overlap, red, low-temperature coloring and high-temperature coloring overlap A green color was obtained in the part, and a black color was obtained in the part where all the colors were overlapped.

Further, the whiteness of each uncolored portion was measured using a Hunter whiteness meter (D type, manufactured by Toyo Seiki Co., Ltd.) and found to be 90.2%.

[0076]

The multicolor heat-sensitive recording material of the present invention has a wide range of hues that can be developed, and even when it is affected by external environmental conditions such as heat and humidity, there is very little discoloration of the undeveloped portion, and it is possible to fix the light when fixing with light. There is little discoloration of the blank area, and it is extremely useful in practice.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 27, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

Embedded image[However, in the formula (I), R¹ Is a hydrogen atom, C₁ ~ C₆ Chain A
Luquil, C_Three ~ C₆ Cyclic alkyl, substituted or unsubstituted C₇ 
~ C₂₀Aralkyl group, substituted or unsubstituted phenyl group, or
Is C_Two ~ C_TenRepresents an alkoxyalkyl group, X¹ ~ X⁸ 
Are, independently of each other, a hydrogen atom, C₁ ~ C_Four Al
Kill group, C₁ ~ C₈ Alkoxy group, halogen atom,
Rogenated methyl group, nitro group, or substituted or unsubstituted
Represents a mino group, X¹ And X^Two , X^Two And X^Three , X^Three And X^Four ,
X^Five And X⁶ , X⁶ And X⁷ , X⁷ And X ⁸ Is adjacent to them
A substituted or unsubstituted aromatic cyclic structure together with
May be formed, X⁹ Is C₁ ~ C₆ Alkyl group, C₁ ~
C₈ An alkoxyl group, a substituted or unsubstituted amino group, or
Represents a halogen atom, m represents 0, or an integer of 1 to 4
In the formula (II), W represents a carbon atom or a nitrogen atom, and Z is
Represents a hydrogen atom or a group of formula (III), Y¹ Is a hydrogen atom
Alternatively, it represents a group of formula (IV) or formula (V), and Y^Two Is the expression (I
V) or a group of formula (V), X^TenIs C₁ ~ C₆ Al
Kill group, C₁ ~ C ₈ Alkoxyl group, substituted or unsubstituted
Represents a mino group or a halogen atom, n is 0, or 1 to
Represents an integer of 4 and in the formula (III), R^Two Is a hydrogen atom, C₁ ~ C₆ Chained archi
Le, C_Three ~ C₆ Cyclic alkyl, substituted or unsubstituted C₇ ~ C
₂₀Aralkyl group, substituted or unsubstituted phenyl group or C_Two 
~ C_TenRepresents an alkoxyalkyl group, R in the formula (IV)^Three And R^Four Respectively from each other
Independently, hydrogen atom, C ₁ ~ C₈ Chain alkyl, C_Three ~ C
₆ Cyclic alkyl, substituted or unsubstituted C₇ ~ C₂₀Aralkyl
Group, substituted or unsubstituted phenyl group, or C_Two ~ C_TenAl
Represents a oxyalkyl group;^Three And R^Four Are each other
Pyrrolidino group, piperidino together with two adjacent nitrogen atoms
Group or a morpholino group may be formed, and X¹¹~ X¹⁴
Are, independently of each other, a hydrogen atom, C₁ ~ C_Four Al
Kill group, C₁ ~ C₈ Represents an alkoxyl group, and in the formula (V), R^Five And R⁶ Respectively from each other
Independently, hydrogen atom, C ₁ ~ C₈Chain alkyl, C_Three ~ C
₆ Cyclic alkyl, substituted or unsubstituted C₇ ~ C₂₀Aralkyl
Represents a group or a substituted or unsubstituted phenyl group. ]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

Examples of the photoreducing agent used in the present invention include quinone, disulfide, diazoanthrone, diazonium salt, diazophenanthrone, aromatic azide, acyloin, which are described in JP-A No. 50-139724. Aromatic ketones, aromatic carbazides, diazo sulfonates, compounds such as 2H-benzimidazole, and compounds such as anthrone and phenazine can be used.
Specific examples thereof include 1,4-naphthoquinone, p-quinone, phenanthrenequinone, bilenquinone, 1,2-benzanthraquinone, 1-naphthyl disulfide,
-Diazoanthrone, benzophenone, benzoin, benzoin isobutyl ether, 2,2-dimethyl-2H
-Benzimidazole, benzuanthrone, phenazine and the like. Of course, the photoreducing agent used in the present invention is not limited to these, and if necessary, one kind or two or more kinds of compounds can be used in combination.
In this case, utilizing the difference in the wavelength of photoactivation of each compound,
Each photoreducing agent can be activated with light of a different wavelength. The amount of the photoreducing agent used is not particularly limited.
It is preferable to mix and use it in a ratio of up to 2000% by weight, and more preferably 20 to 500% by weight.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

As a specific example of the counter anion of the diazonium salt
Cl ・ 1/2 (ZnCl_Two ) ^-, BF_Four ^-, PF
₆ ^-, B (Ph)_Four ^-, C_nF_{2n + 1}COO^-(N is 3 ~
9), C_mF_{2m + 1}SO_Three ^-(M represents 2 to 8
), (C_kF_{2k + 1}SO_Two )_Two CH^-(K is 1-18
Represent), C₁ F_21-1OC₆ H_Four SO_Three ^-(1 is 5-10
Can be mentioned).

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Satoshi Fukui Shin-Oji Paper Co., Ltd. Shinonome Research Center, 1-10-6 Shinonome, Koto-ku, Tokyo

Claims (6)

[Claims] 1. A support and two or more heat-sensitive color forming layers formed thereon and coloring in different color tones, wherein at least one of the heat-sensitive color forming layers contains an oxidative color-forming leuco dye. And a oxidant and a photoreducing agent, and a multicolor heat-sensitive recording material. 2. The multicolor thermosensitive recording material according to claim 1, wherein at least one of the oxidative coloring leuco dye, the oxidizing agent, and the photoreducing agent is contained in microcapsules. 3. The oxidative color-forming leuco dye is the following general
Selected from compounds represented by formulas (I) and (II)
The multi-component according to claim 1 or 2, which comprises at least one
Color heat-sensitive recording material. Embedded image[However, in the formula (I), R¹Is a hydrogen atom, C₁~ C₆Chain A
Luquil, C_Three~ C₆Cyclic alkyl, substituted or unsubstituted C₇
~ C₂₀Aralkyl group, substituted or unsubstituted phenyl group, or
Is C_Two~ C_TenRepresents an alkoxyalkyl group, X¹~ X⁸
Are, independently of each other, a hydrogen atom, C₁~ C_FourAl
Kill group, C₁~ C₈Alkoxy group, halogen atom,
Rogenated methyl group, nitro group, or substituted or unsubstituted
Represents a mino group, X¹And X^Two, X^TwoAnd X^Three, X^ThreeAnd X^Four,
X^FiveAnd X⁶, X⁶And X⁷, X⁷And X ⁸Is adjacent to them
A substituted or unsubstituted aromatic cyclic structure together with
May be formed, X⁹Is C₁~ C₆Alkyl group, C₁~
C₈An alkoxyl group, a substituted or unsubstituted amino group, or
Represents a halogen atom, m represents 0, or an integer of 1 to 4
In the formula (II), W represents a carbon atom or a nitrogen atom, and Z is
Represents a hydrogen atom or a group of formula (III), Y¹Is a hydrogen atom
Alternatively, it represents a group of formula (IV) or formula (V), and Y^TwoIs the expression (I
V) or a group of formula (V), X^TenIs C₁~ C₆Al
Kill group, C₁~ C ₈Alkoxyl group, substituted or unsubstituted
Represents a mino group or a halogen atom, n is 0, or 1 to
Represents an integer of 4 and in the formula (III), R^TwoIs a hydrogen atom, C₁~ C₆Chained archi
Le, C_Three~ C₆Cyclic alkyl, substituted or unsubstituted C₇~ C
₂₀Aralkyl group, substituted or unsubstituted phenyl group or C_Two
~ C_TenRepresents an alkoxyalkyl group, R in the formula (IV)^ThreeAnd R^FourRespectively from each other
Independently, hydrogen atom, C ₁~ C₈Chain alkyl, C_Three~ C
₆Cyclic alkyl, substituted or unsubstituted C₇~ C₂₀Aralkyl
Group, substituted or unsubstituted phenyl group, or C_Two~ C_TenAl
Represents a oxyalkyl group;^ThreeAnd R^FourAre each other
Pyrrolidino group, piperidino together with two adjacent nitrogen atoms
Group or a morpholino group may be formed, and X¹¹~ X¹⁴
Are, independently of each other, a hydrogen atom, C₁~ C_FourAl
Kill group, C₁~ C₈Represents an alkoxyl group, and in the formula (V), R^FiveAnd R⁶Respectively from each other
Independently, hydrogen atom, C ₁~ C₆Chain alkyl, C_Three~ C
₆Cyclic alkyl, substituted or unsubstituted C₇~ C₂₀Aralkyl
Represents a group or a substituted or unsubstituted phenyl group. ] 4. The oxidative coloring leuco dye is 8-diethylamino-11- (2-methoxycarbonylphenyl) benzo [a] xanthene, 8-diethylamino-1.
1- (2-ethoxycarbonylphenyl) benzo [a]
4. The multicolor heat-sensitive recording material according to claim 1, comprising at least one selected from xanthene and 8-diethylamino-11- (2-butoxycarbonylphenyl) benzo [a] xanthene. 5. The heat-sensitive recording material according to claim 1, 2, 3 or 4, wherein the oxidizing agent is a triarylmethyl compound. 6. The oxidizing agent is represented by the following general formula (VI):
Claims comprising at least one compound selected from
Item 5. The heat-sensitive recording material according to item 1, 2, 3 or 4. Embedded image[However, in the formula (VI), X^FifteenIs a halogen atom, substituted carbon
Group, substituted sulfonyl group, nitro group, or cyano group
Then X¹⁶~ X¹⁸Are hydrogen sources, each independently of the other.
Child, halogen atom, substituted carbonyl group, substituted sulfonyl
Group, nitro group, cyano group, C₁~ C₆Chain alkyl, C
_Three~ C₆Cyclic alkyl, substituted or unsubstituted C ₇~ C₂₀Ara
It represents a alkyl group or a substituted or unsubstituted phenyl group. ]