JP2001219659A - Heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-sensitive recording material of improved storage properties for providing a brilliant image of a color in the range from yellow to red. SOLUTION: A heat-sensitive recording material contains at least one kind of diazo compound and at least one kind of coupler to be colored by the reaction with the diazo compound and also contains at least one kind of component represented by general formula (1). In the formula, R1 represents a hydrogen atom, an alkyl group or an aryl group and R2 also represents a hydrogen atom, an alkyl group or an aryl group. Either one of R1 and R2, however, represents the aryl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording material containing a diazo compound and a coupler which develops a color by reacting with the diazo compound.
The present invention relates to a heat-sensitive recording material capable of obtaining a bright yellow to red image.

[0002]

2. Description of the Related Art With the performance improvement of heat-sensitive recording materials,
There is a strong demand for a heat-sensitive recording material that can produce images of yellow to red color, and that has improved shelf life and image storability of the recording material.

A diazo compound reacts with a compound called a coupler such as a phenol derivative or a compound having an active methylene group to form an azo dye. The diazo compound is decomposed by light irradiation and loses its activity. Utilizing this property, diazo compounds have long been used as optical recording materials typified by diazo copy ("Photographic Engineering Fundamentals-Non-silver salt photography-" edited by The Photographic Society of Japan, Corona Co., Ltd. (1)
982) 89-117, pages 182-201).

Recently, it has been applied to a recording material requiring fixing of an image. As a typical example, a diazo compound and a coupler are heated in accordance with an image signal, reacted to form an image, and then irradiated with light. A light-fixing type thermosensitive recording material for fixing an image has been proposed (Koji Sato, et al., Journal of the Institute of Image Electronics Engineers of Japan, Vol. 11, No. 4, (1982) pp. 290-296).

[0005] However, these recording materials have a drawback that the shell life of the recording material is short because the diazo compound gradually decomposes and loses its reactivity even in a dark place. To remedy this drawback, the diazo compound is encapsulated in microcapsules and the diazo compound is
Methods have been proposed for sequestration from substances that promote decomposition, such as bases. By this method, it becomes possible to dramatically improve the shelf life as a recording material (Tomomasa Usami et al., The Journal of the Institute of Electrophotography, Vol. 26, No. 2, (198)
7) pp. 115-125).

[0006] Microcapsules having a glass transition temperature higher than room temperature exhibit heat impermeability at the room temperature because the capsule wall at room temperature shows material non-permeability, but shows material permeability above the glass transition temperature. Can be used for That is, on a support, a thermosensitive recording layer containing a thermoresponsive microcapsule containing a diazo compound and a coupler and a base is coated with a recording material,
(1) It is possible to stably hold a diazo compound for a long time, (2) to form a colored image by heating, and (3) to form an image by light irradiation.

In such a heat-sensitive recording material, a recording material which forms a multicolor image in recent years (Japanese Patent Laid-Open No. 4-135787,
However, as the recording material becomes more sophisticated, it is desired to improve the hue of a color-developed image and improve the performance such as light resistance of an image portion.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object to provide a diazo thermosensitive recording material which is vivid and has good light resistance.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a coupler represented by the general formula (1) or (2)
It has been found that a very good yellow to red image can be obtained by using the compound of formula (1) and the diazo compound, and the present invention has been achieved.

[0010]

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In the formula, R ¹ represents a hydrogen atom, an alkyl group or an aryl group, and R ² represents a hydrogen atom, an alkyl group or an aryl group. However, ^one of R ¹ and R ² represents an aryl group.

[0012]

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In the formula, R ¹ represents a hydrogen atom, an alkyl group or an aryl group, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, Aryloxy group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acyl group, carbamoyl group, acylamino group, sulfamoyl group, sulfonamide group,
Represents a cyano group.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail. In the compound represented by the general formula (1) and the general formula (2), R ¹ represents a hydrogen atom, an alkyl group, an aryl group, R ² represents a hydrogen atom, an alkyl group, an aryl group, R ¹ and R Any one of ² represents at least an aryl group.

In formula (1) or (2), the alkyl groups represented by R ¹ and R ² may have a substituent, and are preferably alkyl groups having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, normal pentyl, normal hexyl, normal heptyl, normal octyl, 3-heptyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, 3, 5,5, -trimethylhexyl, normal dodecyl, cyclohexyl, benzyl, allyl, 2-chloroethyl, 2-methoxyethyl,
2-ethoxyethyl, 2-phenoxyethyl, 2- (2,
5-di-tert-amylphenoxy) ethyl, 2-benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl,
2-Isopropyloxyethyl is preferred. The aryl group represented by R ¹ and R ² may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-
Methylphenyl, 4-chlorophenyl, 2-chlorophenyl, 2-ethoxyphenyl, 3-ethoxyphenyl,
4-ethoxyphenyl, 2-decyloxyphenyl, 3
-Decyloxyphenyl and 4-decyloxyphenyl are preferred.

Among the compounds represented by the general formula (1), a compound represented by the general formula (2) is particularly preferred. That is, the aryl group represented by R ² in the general formula (1) is preferably a phenyl group, has substituents of R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ , and has R ³ , R ⁴ and R 7 ⁵ , R ⁶ and R ⁷ are each a hydrogen atom,
Halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryloxycarbonyl group,
Represents an acyloxy group, an acyl group, a carbamoyl group, an acylamino group, a sulfamoyl group, a sulfonamide group, or a cyano group. Two of R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ may be bonded to form a ring.

As the halogen atom represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ , a fluorine atom, a chlorine atom, a bromine atom and an iodine atom are preferred. Particularly, a chlorine atom and a bromine atom are preferable.

The alkyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted. Alkyl groups having a total of 1 to 30 carbon atoms are preferred, for example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, Normal dodecyl, cyclohexyl, benzyl, α-methylbenzyl, allyl, 2-chloroethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-phenoxyethyl, 2- (2,5-di-tert-amylphenoxy) ethyl, 2 -Benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl, 2-isopropyloxyethyl, 2-methanesulfonylethyl, 2-ethoxycarbonylmethyl, 1- (4-methoxyphenoxy) -2-propyl, trichloro Lomethyl and trifluoromethyl are preferred.

The aryl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted. An aryl group having a total of 6 to 30 carbon atoms is preferable, and for example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-chlorophenyl, and 2-chlorophenyl are preferable.

The alkoxy groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent, and are preferably alkoxy groups having 1 to 20 carbon atoms in total. For example, methoxy,
Ethoxy, normal propyloxy, isopropyloxy, normal butyloxy, tertiary butyloxy, normal hexyloxy, normal octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, normal decyloxy, normal dodecyloxy, Cyclohexyloxy, benzyloxy, allyloxy, 2-methoxyethoxy, 2-ethoxyethoxy, 2-phenoxyethoxy, 2- (2,5-di-tert-amylphenoxy) ethoxy, 2-benzoyloxyethoxy, methoxycarbonylmethyloxy, Methoxycarbonylethyloxy, butoxycarbonylethyloxy and 2-isopropyloxyethyloxy are preferred.

The aryloxy groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ may have a substituent and have a total carbon number of 6
To 30 aryloxy groups are preferred. For example, phenoxy, 4-methylphenoxy, 2-methylphenoxy, and 2-chlorophenoxy are preferred.

The alkylthio groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ may have a substituent and have a total carbon number of 1
To 20 alkylthio groups are preferred. For example, methylthio, ethylthio, normal butylthio, tertiary butylthio, normal hexylthio, normal octylthio, 2-ethylhexylthio, normal dodecylthio, cyclohexylthio, benzylthio, and ethoxycarbonylmethylthio are preferred.

The arylthio groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted. An arylthio group having a total of 6 to 30 carbon atoms is preferable, and for example, phenylthio, 4-methylphenylthio, 3-methylphenylthio, 2-methylphenylthio, 4-chlorophenylthio, and 2-chlorophenylthio are preferable.

The alkylsulfonyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent, and are preferably alkylsulfonyl groups having 1 to 20 carbon atoms in total. For example, methylsulfonyl, ethylsulfonyl, normal butylsulfonyl, normal hexylsulfonyl, normal octylsulfonyl, 2-ethylhexylsulfonyl, normal dodecylsulfonyl, cyclohexylsulfonyl, benzylsulfonyl, and ethoxycarbonylmethylsulfonyl are preferred.

The arylsulfonyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted. An arylsulfonyl group having a total of 6 to 30 carbon atoms is preferred, and for example, phenylsulfonyl, 4-methylphenylsulfonyl, 3-methylphenylsulfonyl, 2-methylphenylsulfonyl, 4-chlorophenylsulfonyl, and 2-chlorophenylsulfonyl are preferred.

The alkoxycarbonyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent, and are preferably alkoxycarbonyl groups having 2 to 20 carbon atoms in total.
For example, methoxycarbonyl, ethoxycarbonyl,
Normal propyloxycarbonyl, isopropyloxycarbonyl, normal butyloxycarbonyl, tertiary butyloxycarbonyl, normal hexyloxycarbonyl, normal octyloxycarbonyl,
2-ethylhexyloxycarbonyl, 3,5,5-trimethylhexyloxycarbonyl, normal dodecyloxycarbonyl, cyclohexyloxycarbonyl, benzyloxycarbonyl, allyloxycarbonyl, 2-
Methoxyethoxycarbonyl, 2-ethoxyethoxycarbonyl, 2-phenoxyethoxycarbonyl, 2-
(2,5-di-tert-amylphenoxy) ethoxycarbonyl, 2-benzoyloxyethoxycarbonyl,
Methoxycarbonylmethyloxycarbonyl, methoxycarbonylethyloxycarbonyl, butoxycarbonylethyloxycarbonyl, and 2-isopropyloxyethyloxycarbonyl are preferred.

The aryloxycarbonyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent,
An aryloxycarbonyl group having a total of 7 to 20 carbon atoms is preferred. For example, phenoxycarbonyl, 4-methylphenoxycarbonyl, 2-methylphenoxycarbonyl, and 2-chlorophenoxycarbonyl are preferred.

The acyloxy group represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent, and is preferably an acyloxy group having 2 to 20 carbon atoms in total. For example, acetyloxy, propanoyloxy, butanoyloxy, hexanoyloxy, octanoyloxy, 2-ethylhexanoyloxy, dodecanoyloxy, benzoyloxy, 4-methoxybenzoyloxy, 2-methoxybenzoyloxy, 4-chloro Benzoyloxy, 2-chlorobenzoyloxy, 4-methylbenzoyloxy,
2-Methylbenzoyloxy is preferred.

The acyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ may have a substituent and have a total carbon number of 2 to 2
An acyl group of 0 is preferred. For example, acetyl, propanoyl, butanoyl, hexanoyl, octanoyl, 2
-Ethylhexanoyl, benzoyl and 2-methylbenzoyl are preferred.

The carbamoyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted. A carbamoyl group having a total of 1 to 30 carbon atoms is preferable, for example, an unsubstituted carbamoyl group, N-methylcarbamoyl,
N, N-dimethylcarbamoyl, N, N-diethylcarbamoyl, N, N-dibutylcarbamoyl, morpholinocarbonyl and piperidinocarbonyl are preferred.

The acylamino group represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent, and is preferably an acyloxy group having 2 to 20 carbon atoms in total. For example, acetylamino, propanoylamino, butanoylamino, hexanoylamino, octanoylamino, 2-ethylhexanoylamino, benzoylamino, 4-methoxybenzoylamino, N-methylacetylamino N-methylbenzoylamino 2-oxapyrrolidino Is preferred.

The sulfamoyl groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent or may be unsubstituted.
Sulfamoyl groups having a total of 1 to 30 carbon atoms are preferred. For example, unsubstituted sulfamoyl groups, N-methylsulfamoyl, N, N-dimethylsulfamoyl, N, N-diethylsulfamoyl, N, N-dibutyl Sulfamoyl, morpholinosulfonyl, piperidinosulfonyl are preferred.

The sulfonamide groups represented by R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ may have a substituent and have a total carbon number of 1
From 20 to 20 sulfonamide groups are preferred. For example, methanesulfonamide, ethanesulfonamide, butanesulfonamide, hexanesulfonamide, benzenesulfonamide, 4-methoxybenzenesulfonamide, N-
Methyl methanesulfonamide is preferred.

The general formula (1) or (2) of the present invention is described below.
Are shown, but the present invention is not limited to these.

[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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The compounds represented by the general formulas (1) and (2) in the present invention are known as magenta couplers for silver halide color photographic light-sensitive materials. These synthesis methods are described in JP-A-46-43947 and JP-A-61-1.
8780, JP-A-61-251684, JP-A-62-3
3177, JP-A-62-33177, JP-A-62-24
9968, JP-A-63-101387, JP-A-1-23
3285, JP-A-2-115183, JP-A-2-201
442, JP-A-3-220191, JP-A-3-2587
80, JP-A-5-222444, JP-A-6-2524
5, JP-A-7-179468, JP-A-7-27841
9, JP-A-7-295172, JP-A-8-60011 and the like.

The coupler according to the present invention can be used in combination with a known coupler according to various purposes such as hue adjustment. Couplers used in combination include active methylene compounds, phenols and naphthols. Specific examples include the following compounds.

Particularly preferred couplers that can be used in the present invention include resorcin, phloroglucin, 2,3-dihydroxynaphthalene, sodium 2,3-dihydroxynaphthalene-6-sulfonate, and morpholinopropyl 1-hydroxy-2-naphthoate. Amide,
Sodium 2-hydroxy-3-naphthalenesulfonate, 2-hydroxy-3-naphthalenesulfonic acid anilide, 2-hydroxy-3-naphthalenesulfonic acid morpholinopropylamide, 2-hydroxy-3-naphthalenesulfonic acid-2-ethylhexyloxypropyl Amide, 2-hydroxy-3-naphthalenesulfonic acid-2-
Ethylhexylamide, 5-acetamido-1-naphthol, 1-hydroxy-8-acetamidonaphthalene-
Sodium 3,6-disulfonate, 1-hydroxy-8
-Acetamidonaphthalene-3,6-disulfonic acid dianilide, 1,5-dihydroxynaphthalene, 2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-
Hydroxy-3-naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid anilide, 5,5-dimethyl-
1,3-cyclohexanedione, 1,3-cyclopentanedione, 5- (2-n-tetradecyloxyphenyl) -1,3-cyclohexanedione, 5-phenyl-
4-methoxycarbonyl-1,3-cyclohexanedione, 5- (2,5-di-n-octyloxyphenyl)
-1,3-cyclohexanedione, N, N'-dicyclohexylbarbituric acid, N, N'-di-n-dodecylbarbituric acid, Nn-octyl-N'-n-octadecyl barbituric acid, N- Phenyl-N '-(2,5
-Di-n-octyloxyphenyl) barbituric acid,
N, N'-bis (octadecyloxycarbonylmethyl) barbituric acid, 1-phenyl-3-methyl-5-
Pyrazolone, 1- (2,4,6-trichlorophenyl)
-3-anilino-5-pyrazolone, 1- (2,4,6-
Trichlorophenyl) -3-benzamido-5-pyrazolone, 6-hydroxy-4-methyl-3-cyano-1-
(2-ethylhexyl) -2-pyridone, 2,4-bis- (benzoylacetamide) toluene, 1,3-bis- (pivaloylacetoamidomethyl) benzene, benzoylacetonitrile, thenoylacetonitrile, acetoacetanilide, benzoylacetanilide, Pivaloylacetoanilide, 2-chloro-5- (Nn-butylsulfamoyl) -1-pivaloylacetamidobenzene, 1- (2-ethylhexyloxypropyl) -3-
Cyano-4-methyl-6-hydroxy-1,2-dihydropyridin-2-one, 1- (dodecyloxypropyl) -3-acetyl-4-methyl-6-hydroxy-
1,2-dihydropyridin-2-one, 1- (4-n-
Octyloxyphenyl) -3-tert-butyl-5
-Aminopyrazole and the like.

For details of the coupler, see JP-A-4-4-2.
01483, JP-A-7-223267, JP-A-7-223
223368, JP-A-7-323660, Japanese Patent Application No. 5
-278608, Japanese Patent Application No. 5-297024, Japanese Patent Application No. 6-18669, Japanese Patent Application No. 6-18670, Japanese Patent Application No. 7
-316280, Japanese Patent Application No.8-027095, Japanese Patent Application No.8-027096, Japanese Patent Application No.8-030799, Japanese Patent Application No.8-12610, Japanese Patent Application No.8-132394, Japanese Patent Application No.8-358755. And Japanese Patent Application Nos. 8-358756 and 9-069990.

The amount of the coupler to be added is 0.1 to 0.1 in the heat-sensitive recording layer.
It is used in the range of 02 to 5 g / m ² , and preferably 0.1 to 4 g / m ^{2 in} terms of effect. When the addition amount is less than 0.02 g / m ² , 5 g / m ²
If the ratio exceeds the above, none of them is preferable from the viewpoint of applicability.

The diazo compounds that can be used in the present invention include, for example, Japanese Patent Application Nos. 11-335801 and 11-335801.
324248, Japanese Patent Application No. 10-187783, Japanese Patent Application No. 10
−151008, Japanese Patent Application No. 8-310133, Japanese Patent Application No. 5-
122865, Japanese Patent Application No. 6-306408, Japanese Patent Application No. 7-9
6671, and Japanese Patent Application No. 2-169489.

For example, a diazo compound of the general formula (3)
The diazo compound of the general formula (4), the diazo compound of the general formula (5), and the diazo compound of the general formula (6) are preferable. Particularly, a diazo compound of the general formula (3) is preferable. Hereinafter, the diazo compounds of the general formulas (3), (4), (5), and (6) will be described.

[0048]

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In the formula, R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group. Group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acyl group, a carbamoyl group, an acylamino group, a sulfamoyl group, a sulfonamide group, a cyano group, or a nitro group, and R ⁵⁵ represents an alkyl group Represents an aryl group.

The halogen atom represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ is a fluorine atom, a chlorine atom, a bromine atom,
An iodine atom is preferred. Particularly, a chlorine atom and a bromine atom are preferable.

The alkyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted. Alkyl groups having a total of 1 to 30 carbon atoms are preferred, for example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, normal hexyl,
Normal octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, normal dodecyl, cyclohexyl,
Benzyl, α-methylbenzyl, allyl, 2-chloroethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-
Phenoxyethyl, 2- (2,5-di-tert-amylphenoxy) ethyl, 2-benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl,
Butoxycarbonylethyl, 2-isopropyloxyethyl, 2-methanesulfonylethyl, 2-ethoxycarbonylmethyl, 1- (4-methoxyphenoxy) -2-
Propyl, trichloromethyl, trifluoromethyl are preferred.

The aryl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted. An aryl group having a total of 6 to 30 carbon atoms is preferred, for example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-
Methylphenyl, 4-chlorophenyl and 2-chlorophenyl are preferred.

The alkoxy group represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and is preferably an alkoxy group having 1 to 20 carbon atoms in total. For example, methoxy, ethoxy, normal propyloxy, isopropyloxy, normal butyloxy, tertiary butyloxy, normal hexyloxy, normal octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, normal dodecyloxy, Cyclohexyloxy, benzyloxy, allyloxy, 2-methoxyethoxy, 2-ethoxyethoxy, 2-phenoxyethoxy, 2- (2,5-di-tert-amylphenoxy) ethoxy, 2-benzoyloxyethoxy, methoxycarbonylmethyloxy, Methoxycarbonylethyloxy, butoxycarbonylethyloxy and 2-isopropyloxyethyloxy are preferred.

The aryloxy groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably aryloxy groups having 60 to 20 carbon atoms in total. For example, phenoxy, 4-methylphenoxy, 2-methylphenoxy, and 2-chlorophenoxy are preferred.

The alkylthio groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably alkylthio groups having 1 to 20 carbon atoms in total. For example, methylthio, ethylthio, normal butylthio, tertiary butylthio, normal hexylthio, normal octylthio, 2-ethylhexylthio, normal dodecylthio, cyclohexylthio, benzylthio, and ethoxycarbonylmethylthio are preferred.

The arylthio groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted.
An arylthio group having a total of 6 to 30 carbon atoms is preferable, and for example, phenylthio, 4-methylphenylthio, 3-methylphenylthio, 2-methylphenylthio, 4-chlorophenylthio, and 2-chlorophenylthio are preferable.

The alkylsulfonyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably alkylsulfonyl groups having 1 to 20 carbon atoms in total.
For example, methylsulfonyl, ethylsulfonyl, normal butylsulfonyl, normal hexylsulfonyl,
Normal octylsulfonyl, 2-ethylhexylsulfonyl, normaldodecylsulfonyl, cyclohexylsulfonyl, benzylsulfonyl, and ethoxycarbonylmethylsulfonyl are preferred.

The arylsulfonyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted. An arylsulfonyl group having a total of 6 to 30 carbon atoms is preferable, for example, phenylsulfonyl, 4-methylphenylsulfonyl, 3-methylphenylsulfonyl, 2-
Methylphenylsulfonyl, 4-chlorophenylsulfonyl, 2-chlorophenylsulfonyl are preferred.

The alkoxycarbonyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably alkoxycarbonyl groups having 2 to 20 carbon atoms in total. For example, methoxycarbonyl, ethoxycarbonyl, normal propyloxycarbonyl, isopropyloxycarbonyl, normal butyloxycarbonyl,
Tert-butyloxycarbonyl, normal hexyloxycarbonyl, normal octyloxycarbonyl, 2-ethylhexyloxycarbonyl, 3,5,5-trimethylhexyloxycarbonyl, normal dodecyloxycarbonyl, cyclohexyloxycarbonyl,
Benzyloxycarbonyl, allyloxycarbonyl,
2-methoxyethoxycarbonyl, 2-ethoxyethoxycarbonyl, 2-phenoxyethoxycarbonyl, 2
-(2,5-Di-tert-amylphenoxy) ethoxycarbonyl, 2-benzoyloxyethoxycarbonyl, methoxycarbonylmethyloxycarbonyl, methoxycarbonylethyloxycarbonyl, butoxycarbonylethyloxycarbonyl, and 2-isopropyloxyethyloxycarbonyl are preferred. .

The aryloxycarbonyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably aryloxycarbonyl groups having 7 to 20 carbon atoms in total. For example, phenoxycarbonyl, 4-methylphenoxycarbonyl, 2-methylphenoxycarbonyl, and 2-chlorophenoxycarbonyl are preferred.

The acyloxy groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent and have a total carbon number of 2
From 20 to 20 acyloxy groups are preferred. For example, acetyloxy, propanoyloxy, butanoyloxy,
Hexanoyloxy, octanoyloxy, 2-ethylhexanoyloxy, dodecanoyloxy, benzoyloxy, 4-methoxybenzoyloxy, 2-methoxybenzoyloxy, 4-chlorobenzoyloxy, 2-
Chlorobenzoyloxy, 4-methylbenzoyloxy and 2-methylbenzoyloxy are preferred.

The acyl group represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and is preferably an acyl group having 2 to 20 carbon atoms in total. For example, acetyl, propanoyl, butanoyl, hexanoyl, octanoyl,
2-ethylhexanoyl, benzoyl and 2-methylbenzoyl are preferred.

The carbamoyl group represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted or unsubstituted. A carbamoyl group having a total of 1 to 30 carbon atoms is preferable. For example, an unsubstituted carbamoyl group, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-diethylcarbamoyl, N, N-dibutylcarbamoyl, morpholinocarbonyl, Peridinocarbonyl is preferred.

The acylamino groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent and have a total carbon number of 2
From 20 to 20 acyloxy groups are preferred. For example, acetylamino, propanoylamino, butanoylamino,
Hexanoylamino, octanoylamino, 2-ethylhexanoylamino, benzoylamino, 4-methoxybenzoylamino, N-methylacetylamino N-methylbenzoylamino 2-oxapyrrolidino are preferred.

The sulfamoyl groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent or may be unsubstituted or unsubstituted. Sulfamoyl groups having a total of 1 to 30 carbon atoms are preferred. For example, unsubstituted sulfamoyl groups, N-methylsulfamoyl, N, N-dimethylsulfamoyl, N,
N-diethylsulfamoyl, N, N-dibutylsulfamoyl, morpholinosulfonyl and piperidinosulfonyl are preferred.

The sulfonamide groups represented by R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ may have a substituent, and are preferably sulfonamide groups having 1 to 20 carbon atoms in total. For example,
Methanesulfonamide, ethanesulfonamide, butanesulfonamide, hexanesulfonamide, benzenesulfonamide, 4-methoxybenzenesulfonamide,
N-methylmethanesulfonamide is preferred.

The alkyl group represented by R ⁵⁵ may have a substituent or may be unsubstituted. Specifically, methyl, ethyl,
n-propyl, isopropyl, normal butyl, tertiary butyl, normal hexyl, normal octyl, 2
-Ethylhexyl, dodecyl, 3,5,5, -trimethylhexyl, normal dodecyl, cyclohexyl, benzyl,
α-methylbenzyl, allyl, 2-methanesulfonylethyl, 2-isopropyloxyethyl, 2- (2,5-di-
Preferred are t-amylphenoxy) ethyl, 2-phenoxyethyl and 1- (4-methoxyphenoxy) -2-propyl.

The aryl group represented by R ⁵⁵ may have a substituent or may be unsubstituted. An aryl group having a total of 6 to 30 carbon atoms is preferable. For example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-chlorophenyl, 2-chlorophenyl, 4-dodecylphenyl, 2-n-octyloxy- 5-t-octylphenyl, 2- (n-hexyloxycarbonyl) phenyl, 2
-(N-octyloxycarbonyl) phenyl, 2- (2
-Ethylhexyloxycarbonyl) phenyl, 2-
(N-decyloxycarbonyl) phenyl, 3- (n-octyloxycarbonyl) phenyl, 4- (2-ethylhexyloxycarbonyl) phenyl, 2- (2- (4-
Methoxyphenoxy) ethoxycarbonyl) phenyl,
2- (2- (4-butoxyphenoxy) ethoxycarbonyl) phenyl is preferred.

Specific examples of the diazo compound of the general formula (3) are shown below, but the present invention is not limited thereto.

[0070]

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Next, the diazo compound of the general formula (4) will be described.

[0072]

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In the formula, R ¹¹ represents an alkyl group or an aryl group, and R ¹² and R ¹³ represent an alkyl group or an aryl group;
X ^- represents an anion.

In formula (4), the alkyl group represented by R ¹¹ may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, secondary butyl, isobutyl, normal pentyl, 2-pentyl, 3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5, 5, -trimethylhexyl, normal dodecyl, cyclohexyl, benzyl, allyl, 2-chloroethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-phenoxyethyl, 2- (2,5-di-
Tertiary amylphenoxy) ethyl, 2-benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl, and 2-isopropyloxyethyl are preferred. The aryl group represented by R ¹¹ may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-
Methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-chlorophenyl, and 2-chlorophenyl are preferred.

The alkyl group represented by R ¹² and R ¹³ may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, normal pentyl, 2-pentyl, 3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, normal Dodecyl, cyclohexyl, benzyl, allyl, 2-methoxyethyl, 2-ethoxyethyl, 2-phenoxyethyl, 2- (2,5-di-tert-amylphenoxy)
Ethyl, 2-benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl, 2-isopropyloxyethyl, 2-
(4-methoxyphenoxy) ethyl, 3- (4-methoxyphenoxy) propan-2-yl, N, N-di (butyl)
Carbamoylmethyl, N, N-di (hexyl) -carbamoylmethyl, N, N-di (ethyl) -carbamoylmethyl,
Piperidinocarbonylmethyl, 2- ｛N, N-di (butyl)
-Carbamoyl} ethyl, 1- {N, N-di (butyl) -carbamoyl} ethyl and pyrrolidinocarbonylmethyl are preferred. The aryl group represented by R ¹² and R ¹³ may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-
Methylphenyl, 2-methylphenyl, 4-chlorophenyl and 2-chlorophenyl are preferred.

[0076] X ^- anion represented by, as the inorganic anions, hexafluorophosphate ion, fluoroboric acid ion, chloride ion, hydrogen sulfate ion, sulfate ion Preferably, poly organic anion Preferred are a fluoroalkyl carboxylate ion, a polyfluoroalkyl sulfonate ion, an aromatic carboxylate ion, an aromatic sulfonate ion, and a tetraaryl borate ion.
Particularly, hexafluorophosphate ion and borofluoride ion are preferable.

Specific examples of the diazo compound of the general formula (4) are shown below, but the present invention is not limited thereto.

[0078]

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[0079]

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Next, the diazo compound of the general formula (5) will be described.

[0081]

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In the formula, R ²¹ , R ²² and R ²³ represent an alkyl group or an aryl group, and X ⁻ represents an anion. In the general formula (5), the alkyl group represented by R ²¹ and R ²² may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, secondary butyl, isobutyl, normal pentyl, 2-pentyl, 3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5, 5, -trimethylhexyl, normal dodecyl,
Cyclohexyl, benzyl, allyl, 2-chloroethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-isopropyloxyethyl, 2-allyloxyethyl, 2
-Butoxyethyl, 2-phenoxyethyl, 2- (2,5-
Di-tert-amylphenoxy) ethyl, 2-benzoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl are preferred. The aryl group represented by R ²¹ and R ²² may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-
Methylphenyl, 2-methylphenyl, 4-chlorophenyl and 2-chlorophenyl are preferred.

The alkyl group represented by R ²³ may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl,
Isopropyl, normal butyl, isobutyl, normal pentyl, 2-pentyl, 3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, normal dodecyl, cyclohexyl, benzyl, allyl, -Methoxyethyl, 2-ethoxyethyl, 2-phenoxyethyl, 2- (2,5-di-tert-amylphenoxy) ethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl are preferred. The aryl group represented by R ²³ may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-
Methylphenyl, 4-chlorophenyl and 2-chlorophenyl are preferred.

The anion represented by X ⁻ is preferably an inorganic anion such as hexafluorophosphate ion, borofluoride ion, chloride ion, hydrogen sulfate ion or sulfate ion. Preferred are a fluoroalkyl carboxylate ion, a polyfluoroalkyl sulfonate ion, an aromatic carboxylate ion, an aromatic sulfonate ion, and a tetraaryl borate ion.
Particularly, hexafluorophosphate ion and borofluoride ion are preferable.

Specific examples of the diazo compound of the general formula (5) are shown below, but the present invention is not limited thereto.

[0086]

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[0087]

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Next, the diazo compound of the general formula (6) will be described.

[0089]

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In the formula, R ³¹ , R ³² and R ³³ represent an alkyl group or an aryl group, and X ⁻ represents an anion. In the general formula (6), the alkyl group represented by R ³¹ may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms in total. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, secondary butyl, isobutyl, normal pentyl, 2
-Pentyl, 3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5,
5, -trimethylhexyl, normal dodecyl, cyclohexyl, benzyl, 2-chlorobenzyl, 2-methylbenzyl, 3-chlorobenzyl, 3-methylbenzyl, 3
-Methoxybenzyl, α-methylbenzyl, allyl, 2
-Chloroethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl are preferred. The aryl group represented by R ³¹ may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-chlorophenyl, 2-
Chlorophenyl is preferred.

The alkyl group represented by R ³² and R ³³ may have a substituent, and is preferably an alkyl group having 1 to 30 carbon atoms. For example, methyl, ethyl, normal propyl, isopropyl, normal butyl, secondary butyl, isobutyl, normal pentyl, 2-pentyl,
3-pentyl, isopentyl, normal hexyl, normal octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, normal decyl, normal dodecyl, cyclohexyl, benzyl, allyl, 2-chloroethyl, 2
-Isopropyloxyethyl, 2-allyloxyethyl, 2-butoxyethyl, 2-phenoxyethyl, 2-
(2,5-di-tert-amylphenoxy) ethyl, 2
-Benzoyloxyethyl, 2-octanoyloxyethyl, 2-decanoyloxyethyl, dodecanoyloxyethyl, methoxycarbonylmethyl, methoxycarbonylethyl, butoxycarbonylethyl are preferred. R
^The aryl group represented by ³² or R ³³ may have a substituent, and is preferably an aryl group having 6 to 30 carbon atoms in total. For example, phenyl, 4-methylphenyl, 3-methylphenyl, 2-methylphenyl, 4-chlorophenyl, 2-
Chlorophenyl is preferred. R ³² and R ³³ may combine to form a nitrogen-containing heterocyclic ring. The nitrogen-containing heterocyclic ring is preferably pyrrolidino, piperidino, morpholino,
-Acylpiperazino, 4-sulfonylpiperazino, hexamethyleneimino, indolino and the like are preferred.

[0092] X ^- anion represented by, as the inorganic anions, hexafluorophosphate ion, fluoroboric acid ion, chloride ion, hydrogen sulfate ion, sulfate ion Preferably, poly organic anion Preferred are a fluoroalkyl carboxylate ion, a polyfluoroalkyl sulfonate ion, an aromatic carboxylate ion, an aromatic sulfonate ion, and a tetraaryl borate ion.
Particularly, hexafluorophosphate ion and borofluoride ion are preferable.

Specific examples of the diazo compound of the general formula (6) are shown below, but the present invention is not limited thereto.

[0094]

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The amount of the diazo compound applied is preferably 0.02 to 5 g / m ² as a solid content in the heat-sensitive recording layer.
0.1-4 g / m < ² > is more preferable. When the coating amount is 0.
If it is less than 02 g / m ² , the color density may be insufficient, and if it exceeds 5 g / m ² , it is not economically preferable.

In the present invention, it is preferable to add an organic base for the purpose of accelerating the coupling reaction between the diazo compound and the coupler. The organic base is preferably contained in the light and heat sensitive recording layer together with the diazo compound and the coupler, and may be used alone or in combination of two or more. Examples of the organic base include tertiary amines, piperidines, piperazines, amidines, formamidines,
Examples include nitrogen-containing compounds such as pyridines, guanidines, and morpholines. Further, Japanese Patent Publication No. 52-46806, Japanese Patent Application Laid-Open No. 62-70082, Japanese Patent Application Laid-Open No.
No. 69745, JP-A-60-94381, JP-A-57-123086, JP-A-58-1347
No. 901, JP-A-60-49991, JP-B-2-24916, JP-B-2-28479,
JP-A-60-165288, JP-A-57-185
No. 430 can also be used.

Among them, N, N'-bis (3-phenoxy-2-hydroxypropyl) piperazine, N, N '
-Bis [3- (p-methylphenoxy) -2-hydroxypropyl] piperazine, N, N'-bis [3- (p-
Methoxyphenoxy) -2-hydroxypropyl] piperazine, N, N'-bis (3-phenylthio-2-hydroxypropyl) piperazine, N, N'-bis [3-
(Β-naphthoxy) -2-hydroxypropyl] piperazine, N-3- (β-naphthoxy) -2-hydroxypropyl-N′-methylpiperazine, 1,4-bis {[3
Piperazines such as-(N-methylpiperazino) -2-hydroxy] propyloxy} benzene, N- [3- (β
-Naphthoxy) -2-hydroxy] propylmorpholine, 1,4-bis (3-morpholino-2-hydroxy-
Morpholines such as propyloxy) benzene and 1,3-bis (3-morpholino-2-hydroxy-propyloxy) benzene, and piperidines such as N- (3-phenoxy-2-hydroxypropyl) piperidine and N-dodecylpiperidine. And guanidines such as triphenylguanidine, tricyclohexylguanidine and dicyclohexylphenylguanidine.

When an organic base is optionally contained,
The content of the organic base in the heat-sensitive recording layer is preferably 0.1 to 30 parts by weight based on 1 part by weight of the diazo compound.

In the present invention, in addition to the above-mentioned organic bases,
For the purpose of accelerating the coloring reaction, a coloring aid may be added to the light and heat sensitive recording layer. The coloring aid is a substance that increases the coloring density during heating recording or lowers the minimum coloring temperature, and lowers the melting point of a coupler, an organic base, a diazo compound, or the like, or lowers the softening point of the capsule wall. By this action, a diazo compound, an organic base, a coupler and the like are made to easily react.

As described above, the color-forming aids include, for example, phenol derivatives, naphthol derivatives, alkoxy-substituted benzenes, alkoxy-substituted naphthalenes, and aromatics so as to enable rapid and complete thermal printing with low energy. Examples include ethers, thioethers, esters, amides, ureides, urethanes, sulfonamide compounds and hydroxy compounds.

For the purpose of improving the light fastness of a color image to light and heat, or reducing yellowing due to light in an unprinted portion (non-image portion) after fixing, the following known antioxidants, etc. It is also preferable to use Examples of the antioxidant include, for example, European Patent Publication No. 223739.
JP-A-309401, JP-A-309402, JP-A-310551, JP-A-310552, JP-A-559416, and German Published Patent No. 343.
5443, JP-A-54-48535, 6
JP-A-2-262407, JP-A-63-113536, JP-A-63-163351, JP-A-2-2626
54, JP-A-2-71262, JP-A-3-
JP-A-121449, JP-A-5-61166, JP-A-5-119449, U.S. Pat.
262, U.S. Pat. No. 4,980,275, and the like.

Further, it is also effective to use various known additives already used in heat-sensitive recording materials and pressure-sensitive recording materials. Specific examples of the various additives include JP-A-60-107384, JP-A-60-107383, JP-A-60-125470 and JP-A-60-1254.
No. 71, No. 60-125472, No. 60-2
87485, 60-287486, 6
Nos. 0-287487, 60-287488, 61-160287, and 61-18548.
No. 3, No. 61-211079, No. 62-14
Nos. 6678, 62-146680, 62
-146679, 62-282885,
JP-A-63-051174, JP-A-63-89877, JP-A-63-88380, and JP-A-63-088381
JP-A-63-203372 and JP-A-63-224.
Nos. 989 and 63-251282, 63-251
267594, 63-182484, JP-A-1-239282, 4-291684, 4-291684, 5-188687, 5-188686 and 5-188686. 110490
JP-A-5-1108437 and JP-A-5-1703
No. 61, JP-B-48-043294, 48
Compounds described in JP-A-033212 can be exemplified.

Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2 -Dihydroquinoline, 6-ethoxy-1-
Phenyl-2,2,4-trimethyl-1,2,3,4-
Tetrahydroquinoline, 6-ethoxy-1-octyl-
2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, nickel cyclohexanoate, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2- Ethyl hexane, 2
-Methyl-4-methoxy-diphenylamine, 1-methyl-2-phenylindole and the like.

The amount of the antioxidant and various additives is 0.05 to 1 with respect to 1 part by weight of the diazo compound.
00 parts by weight is preferable, and 0.2 to 30 parts by weight is more preferable.

The known antioxidants and various additives are
It may be used in a microcapsule together with the diazo compound, may be used as a solid dispersion with a coupler, an organic base, other color-forming aids, or the like, or may be used as an emulsion with a suitable emulsifying aid, Alternatively, both forms can be used in combination. The antioxidant and various additives may be used alone or in combination of two or more. In the case of using two or more kinds in combination, those having structurally classified and different structures such as anilines, alkoxybenzenes, hindered phenols, hindered amines, hydroquinone derivatives, phosphorus compounds, sulfur compounds, etc. May be combined, or the same may be combined.

Further, the antioxidant and various additives need not be added to the same layer, and a protective layer may be provided on the light and heat sensitive recording layer, and may be added to or present in the protective layer.

The light- and heat-sensitive recording material of the present invention contains a free radical generator (a compound which generates free radicals by light irradiation) for use in a photopolymerizable composition or the like for the purpose of reducing the yellowing of the background after recording. ) Can be added. Examples of the free radical generator include aromatic ketones, quinones, benzoin, benzoin ethers, diazo compounds, organic disulfides, and acyl oxime esters. The amount of the free radical generator is preferably 0.01 to 5 parts by weight per 1 part by weight of the diazo compound.

Similarly, for the purpose of reducing yellow coloration, a polymerizable compound having an ethylenically unsaturated bond (hereinafter, referred to as a polymerizable compound).
Vinyl monomer). A vinyl monomer is a compound having at least one ethylenically unsaturated bond (vinyl group, vinylidene group, etc.) in its chemical structure, and has a chemical form of a monomer or prepolymer. Examples thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohols, and amides of unsaturated carboxylic acids and aliphatic polyamine compounds. The vinyl monomer is used in an amount of 0.2 to 20 parts by weight based on 1 part by weight of the diazo compound. The free radical generator and the vinyl monomer can be used in a microcapsule together with a diazo compound.

Further, citric acid, tartaric acid, oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid and the like can be added as an acid stabilizer.

Examples of the binder used for the light and heat sensitive recording layer include known water-soluble polymer compounds and latexes. Examples of the water-soluble polymer compound include methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, starch derivatives, casein, gum arabic, gelatin, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, polyvinyl Alcohol, epichlorohydrin modified polyamide, isobutylene-maleic salicylic anhydride copolymer, polyacrylic acid, polyacrylamide, and the like, and modified products thereof, and the like. Examples of the latex include styrene-butadiene rubber latex, methyl acrylate- Butadiene rubber latex, vinyl acetate emulsion and the like.

The light and heat sensitive recording material of the present invention may contain a pigment in the light and heat sensitive recording layer or in another layer. As the pigment, any known organic or inorganic pigment can be used.For example, kaolin, calcined kaolin, talc, fluorite, diatomaceous earth, calcium carbonate,
Aluminum hydroxide, magnesium hydroxide, zinc oxide,
Examples include lithopone, amorphous silica, colloidal silica, calcined stone, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, microballoons, urea-formalin filler, polyester particles, and cellulose filler. Also,
In the light and heat sensitive recording layer or other layers, if necessary, known additives such as a wax, an antistatic agent, an antifoaming agent, a conductive agent, a fluorescent dye, a surfactant, an ultraviolet absorber and a precursor thereof. Can also be used.

In the present invention, the diazo compound is preferably encapsulated in microcapsules from the viewpoint that the raw preservability of the light and heat sensitive recording material can be further improved. The microcapsules are preferably made of a polymer that is impermeable to substances at normal temperature and becomes permeable to substances when heated, and particularly has a glass transition temperature of 60 to 200 ° C.
More preferably, the polymer is formed of Examples of the polymer include polyurethane, polyurea,
Examples thereof include polyamide, polyester, urea / formaldehyde resin, melamine resin, polystyrene, styrene / methacrylate copolymer, styrene / acrylate copolymer, and a mixed system thereof. It is preferably formed from molecules (for example, polyurethane, polyurea, etc.).

The method for forming the microcapsules can be appropriately selected from conventionally known methods. Among them, an interfacial polymerization method or an internal polymerization method is suitable. Details of the capsule forming method and specific examples of the reactants are described in specifications such as U.S. Patent Nos. 3,726,804 and 3,796,669. For example, when polyurea or polyurethane is used as a wall material of a microcapsule, a polyisocyanate and a second substance (eg, polyol, polyamine) which reacts with the polyisocyanate to form a capsule wall are mixed in an aqueous medium or an oil medium to be encapsulated. Then, these are emulsified and dispersed in water and then heated to cause a polymer forming reaction at the oil droplet interface to form microcapsule walls. Note that polyurea is generated even when the addition of the second substance is omitted.

Hereinafter, an example of a method for producing a diazo compound-containing microcapsule (polyurea / polyurethane wall) in the present invention will be described. First, a diazo compound is dissolved or dispersed in a hydrophobic organic solvent serving as a core of a capsule. In this case, the organic solvent has a boiling point of 100
Organic solvents at ~ 300 ° C are preferred. In the core solvent, polyvalent isocyanate is further added as a wall material (oil phase).

On the other hand, as the aqueous phase, an aqueous solution (aqueous phase) in which a water-soluble polymer such as polyvinyl alcohol or gelatin is dissolved is prepared, and then the oil phase is charged and emulsified and dispersed by means such as a homogenizer. At this time, the water-soluble polymer acts not only as a protective colloid that can make the emulsification and dispersion uniform and easy, but also acts as a dispersion medium for stabilizing the emulsified and dispersed solution. A surfactant may be added to at least one of the oil phase and the aqueous phase for the purpose of more stably emulsifying and dispersing.

The amount of the polyvalent isocyanate used is determined so that the average particle size of the microcapsules is 0.3 to 12 μm and the wall thickness is 0.01 to 0.3 μm. The dispersed particle diameter is generally about 0.2 to 10 μm. In the emulsified dispersion, a polymerization reaction of the polyvalent isocyanate occurs at the interface between the oil phase and the aqueous phase to form a polyurea wall. If a polyol is added to the aqueous phase, the polyvalent isocyanate and the polyol can react to form a polyurethane wall.

To increase the reaction rate, it is preferable to keep the reaction temperature high or to add an appropriate polymerization catalyst. Details of polyvalent isocyanates, polyols, reaction catalysts, and polyamines for forming a part of the wall material are described in detail in Polygraphs (Polyurethane Handbook, edited by Keiji Iwata, Nikkan Kogyo Shimbun (1987)).

As the polyvalent isocyanate used as a raw material for the microcapsule wall, a compound having a trifunctional or more isocyanate group is preferable, but a bifunctional isocyanate compound may be used in combination. Specifically, diisocyanates such as xylene diisocyanate and hydrogenated products thereof, hexamethylene diisocyanate, tolylene diisocyanate and hydrogenated products thereof, and isophorone diisocyanate are used as main raw materials, and dimers or trimers thereof (buret or isocyanurate) are used. ) In addition, adducts of polyols such as trimethylolpropane and bifunctional isocyanates such as xylylene diisocyanate, which are polyfunctional, and adducts of polyols such as trimethylolpropane and bifunctional isocyanates such as xylylene diisocyanate Examples include compounds into which a high molecular weight compound such as polyether having active hydrogen such as polyethylene oxide is introduced, and a formalin condensate of benzene isocyanate. JP-A-62-212190, JP-A-Hei-4
-26189, JP-A-5-317694,
Compounds described in Japanese Patent Application No. 8-268721 are preferred.

Further, a polyol or polyamine may be added to a hydrophobic solvent serving as a core or a water-soluble polymer solution serving as a dispersion medium, and used as one of the raw materials for the microcapsule wall. Specific examples of these polyols or polyamines include propylene glycol, glycerin, trimethylolpropane, triethanolamine, sorbitol, hexamethylenediamine and the like. When a polyol is added, a polyurethane wall is formed.

The hydrophobic organic solvent used for dissolving or dispersing the above diazo compound to form the core of the microcapsule includes alkylnaphthalene, alkyldiphenylethane, alkyldiphenylmethane, alkylbiphenyl, alkylterphenyl, chlorinated Paraffins, phosphates, maleates, adipic esters, phthalates, benzoates, carbonates, ethers, sulfates, sulfonates, etc., acrylates, methacrylic acid Other organic solvents such as acid esters are preferred.

When the solubility of the diazo compound to be encapsulated in these solvents is poor, a low-boiling solvent having high solubility for the diazo compound to be used can be used in combination. Therefore, the diazo compound preferably has an appropriate solubility in these high-boiling hydrophobic organic solvents and low-boiling auxiliary solvents, and specifically has a solubility of 5% or more in these solvents. Is preferred. The solubility in water is preferably 1% or less. Examples of the low-boiling solvent include ethyl acetate, butyl acetate, methylene chloride, tetrahydrofuran, acetonitrile, acetone and the like.

The water-soluble polymer used as a protective colloid in the aqueous phase (water-soluble polymer aqueous solution) in which the oil phase is dispersed is preferably a water-soluble polymer having a solubility in water of 5% or more at the temperature to be emulsified. Specifically, the following are mentioned. The water-soluble polymer can be appropriately selected from known anionic polymers, nonionic polymers, and amphoteric polymers.

As the anionic polymer, any of natural and synthetic polymers can be used. For example, -COO
-, - it includes those having a linking group such as - SO _2.
Specifically, natural products such as casein, arabic gum, alginic acid, and pectin; gelatin derivatives such as carboxymethyl cellulose and phthalated gelatin; starch derivatives such as sulfated starch; semi-synthetic products such as sulfated cellulose and lignin sulfonic acid; -Maleic anhydride-based (including hydrolyzate) copolymers such as maleic anhydride copolymer, ethylene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer; polyacrylamide and derivatives thereof; Acrylic acid (methacrylic acid) polymers and copolymers such as ethylene-acrylic acid copolymer and vinyl acetate-acrylic acid copolymer; ethylene-vinyl acetate copolymer; vinylbenzenesulfonic acid polymer and copolymer And synthetic products such as polymers and carboxy-modified polyvinyl alcohol.

Examples of the nonionic polymer include polyvinyl alcohol and modified products thereof, polyvinyl pyrrolidone, hydroxyethyl cellulose, methyl cellulose and the like. Examples of the amphoteric polymer include gelatin. Among them, gelatin, gelatin derivatives and polyvinyl alcohol are preferred. The water-soluble polymer is 0.01
Used as an aqueous solution of 10 to 10% by weight.

The water-soluble polymer preferably has no or low reactivity with an isocyanate compound.
Those having a reactive amino group in the molecular chain, such as gelatin, need to be modified beforehand to eliminate the reactivity.

As the surfactant, one that acts on the water-soluble polymer and does not cause precipitation or aggregation can be appropriately selected from anionic or nonionic surfactants. Among them, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium dioctyl sulfosuccinate, polyalkylene glycol (for example, polyoxyethylene nonyl phenyl ether) and the like are preferable. The amount of the surfactant added is 0.1 to 5%, especially 0.5%, based on the weight of the oil phase.
It is preferably about 2%.

For the emulsification and dispersion, a known emulsification apparatus such as a homogenizer, a Manton-Gawley, an ultrasonic disperser, a dissolver, and a Keddy mill can be used. After emulsification,
To accelerate the capsule wall formation reaction, 30
Warm to ~ 70 ° C. In order to prevent aggregation of the capsules during the reaction, it is necessary to reduce the probability of collision between the capsules by adding water or to perform sufficient stirring.

During the reaction, a dispersion for preventing aggregation may be added again. Generation of carbon dioxide gas is observed with the progress of the polymerization reaction, and the end thereof can be regarded as an approximate end point of the capsule wall forming reaction. Usually, by reacting for several hours, the desired diazo compound-encapsulated microcapsules can be obtained.

The coupler used in the present invention can be used as a solid dispersion with a water-soluble polymer by a sand mill or the like, if desired, together with an organic base and other color-forming auxiliaries. After dissolving in an organic solvent, this is preferably mixed with an aqueous phase having a surfactant and / or a water-soluble polymer as a protective colloid to obtain an emulsified dispersion. From the viewpoint of facilitating emulsification and dispersion,
It is preferable to use a surfactant.

The organic solvent that is hardly soluble or insoluble in water can be appropriately selected from, for example, high boiling oils described in JP-A-2-141279. Among them, esters are preferable from the viewpoint of the emulsion stability of the emulsified dispersion, and a compound represented by the general formula (1) or (2),
Tricresyl phosphate is more preferred. Said oils,
Alternatively, it can be used in combination with another oil.

An auxiliary solvent can be further added to the organic solvent as a low boiling point dissolution aid. As the auxiliary solvent, for example, ethyl acetate, isopropyl acetate, butyl acetate, methylene chloride and the like are preferable. In some cases, only a low-boiling auxiliary solvent without a high-boiling oil can be used.

The light- and heat-sensitive recording material of the present invention is prepared by preparing a coating liquid (light- and heat-sensitive recording layer coating liquid) containing a microcapsule containing a diazo compound, a coupler, and, if necessary, an organic base and other additives. Then, it is coated on a support such as paper or a synthetic resin film by a known coating method, and dried to form. As the solids weight of the light and heat sensitive recording layer, 2.5~30g / m ² is preferred.

Examples of the coating method include bar coating, blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, curtain coating and the like. In the light- and heat-sensitive recording material of the present invention, microcapsules, couplers, organic bases and the like may be contained in the same layer, or may be of a laminated type in which they are contained in different layers. Further, after providing an intermediate layer described in Japanese Patent Application No. 59-177669 on a support, a light- and heat-sensitive recording layer can be formed by coating.

In the heat-sensitive recording material of the present invention, if necessary, a protective layer may be further provided on the light- and heat-sensitive recording layer.
Two or more protective layers may be laminated as necessary. Materials used for the protective layer include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer, silicon-modified polyvinyl alcohol, starch, modified starch, methyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, gelatins, gum arabic, and casein. Styrene-maleic acid copolymer hydrolyzate, styrene-maleic acid copolymer half ester hydrolyzate, isobutylene-maleic anhydride copolymer hydrolyzate,

Water-soluble polymer compounds such as polyacrylamide derivatives, polyvinyl pyrrolidone, sodium polystyrene sulfonate, sodium alginate, styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion, etc. Latexes are used. The water-soluble polymer compound in the protective layer can be cross-linked to further improve the storage stability, and a known cross-linking agent can be used as the cross-linking agent. Specifically, N-methylol urea, N-methylol melamine, urea
Examples include water-soluble initial condensates such as formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax, and polyamide epichlorohydrin.

The protective layer may further contain known pigments, metal soaps, waxes, surfactants, ultraviolet absorbers and precursors thereof. The protective layer is prepared by preparing a coating solution containing the above components (protective layer coating solution),
It can be formed by coating and drying. The coating amount of the protective layer coating solution (solid content), preferably ^{0.2~5g / m 2, 0.5~2g / m} 2 is more preferable. The thickness of the protective layer is preferably from 0.2 to 5 μm,
２2 μm is more preferable.

As the support, ordinary pressure-sensitive paper or thermal paper,
Any paper support used for dry or wet diazo copy paper can be used, and acid paper, neutral paper, coated paper, plastic film laminated paper, synthetic paper, plastic film, etc. can be used. it can. A back coat layer may be provided to correct the curl balance of the support or to improve the chemical resistance from the back surface, or to form a label by combining release paper with an adhesive layer on the back surface. You may. This back coat layer can be provided in the same manner as the protective layer.

[0138]

[Example 1]

(Preparation of diazo compound-containing microcapsule liquid A) 4.4 g of the above-mentioned diazo compound (exemplified compound E-5) as a core substance and KMC-500 (manufactured by Kureha Chemical Industry Co., Ltd.) in 13.1 g of ethyl acetate. 0 g was added and mixed uniformly. Then, Takenate D1 was added to this mixture as a wall material.
10N (Takeda Pharmaceutical Co., Ltd.) and Takenate D1
16N (manufactured by Takeda Pharmaceutical Co., Ltd.)
g, 4.1 g, and 2.7 g of Millionate MR200 (manufactured by Nippon Polyurethane Industry Co., Ltd.) were added to obtain a liquid X. Next, 62.7 g of 8% aqueous solution of phthalated gelatin and 17.
4g, sucrapAG-8 (manufactured by Nippon Seika Co., Ltd.)
The above solution X was added to 0.4 g of the mixture, and the mixture was emulsified and dispersed at 40 ° C. and a rotation number of 8000 rpm for 10 minutes using a homogenizer. After 50 g of water and 0.26 g of diethylenetriamine were added to the obtained emulsion to homogenize it, a microencapsulation reaction was performed at 60 ° C. for 3 hours with stirring.
Thereafter, the temperature of the solution was lowered to 35 ° C., and 10 g of an ion exchange resin “Amberlite IRA68” (manufactured by Organo) and 20 g of “Amberlite IRC50” (manufactured by Organo) were added, followed by stirring for 1 hour. Thereafter, 1.0 g of a 1% aqueous solution of hydroquinone was added and stirred. Thus, the desired diazo compound-containing microcapsule solution was obtained. The average particle size of this microcapsule is 0.3-0.4
Micrometer.

(Preparation of Coupler Emulsion B) Ethyl acetate 1
In 5.7 g, 4.0 g of a coupler (exemplified compound C-2), 2.9 g of triphenylguanidine, 5.0 g of tricresyl phosphate and 5.0 g of pionin A-41C (manufactured by Takemoto Yushi) were dissolved, and the Y solution was added. Obtained. Next, the Y solution was added to an aqueous solution in which 77 g of a 15% aqueous solution of lime-processed gelatin and 105 g of water were uniformly mixed at 40 ° C., and emulsified and dispersed at 40 ° C. at 10,000 rpm for 10 minutes using a homogenizer. The obtained emulsion was stirred at 40 ° C. for 2 minutes to remove ethyl acetate, and water was added to obtain a coupler emulsion B.

(Preparation of Coating Solution C for Thermosensitive Recording Layer) 10 g of diazo compound-containing microcapsule solution A, coupler emulsion B
30 g of the mixture was mixed to obtain a heat-sensitive recording layer coating solution C.

(Preparation of Coating Solution D for Protective Layer) 5.0% by Weight
Itaconic acid-modified polyvinyl alcohol ("KL-31
8 ", manufactured by Kuraray Co., Ltd.) and 20.5% by weight of zinc stearate dispersion (" Hydrin F115 ",
2.0 g of Chukyo Yushi Co., Ltd. was added, and C ₁₂ H ₂₅ O (CH ₂
8.4 g of a 2% by weight aqueous solution of CH ₂ O) H, 8.0 g of a fluorine-based release agent (“ME-313”, manufactured by Daikin), and 0 flour starch (“KF-4”, manufactured by Kagoshima Starch) 0 .5g
Was added and stirred uniformly. This will be referred to as "mother liquor". Separately, 12.5 g of a 20% by weight aqueous solution of ion-exchanged chao gloss (manufactured by Shiraishi Industry Co., Ltd.),
0.06 g (manufactured by Kao Corporation), 1.87 g of Hydrin Z-7 (manufactured by Chukyo Yushi Co., Ltd.), 1.25 g of 10% by weight polyvinyl alcohol ("PVA105", manufactured by Kuraray Co., Ltd.), and
2% by weight aqueous solution of sodium dodecyl sulfonate 0.39
g were mixed and finely dispersed with a dyno mill. This liquid is referred to as “pigment liquid”. To 80 g of the mother liquor, 4.4 g of the pigment solution was added and stirred for 30 minutes or more. After that, Wet
2.8 parts of master500 (manufactured by Toho Chemical Co., Ltd.) was added, and the mixture was further stirred for 30 minutes or more to prepare a target coating liquid for a protective layer.

(Coating) A thermosensitive recording layer coating solution C and a protective layer coating solution D were sequentially applied to a photographic paper support obtained by laminating polyethylene on a high-quality paper with a wire bar, dried at 50 ° C., and dried at 50 ° C. Recording material (1) was obtained. The coating amounts of the thermal recording layer and the protective layer as solids were 3.5 g /
m ² , 1.2 / m ² .

Example 2 Coupler emulsion B of Example 1
In the preparation method described above, the above-mentioned exemplified compound (C-
2) 3.0 g of exemplary compound C-31 instead of 4.0 g
A heat-sensitive recording material (2) was obtained in the same manner as in Example 1 except that it was used.

[Comparative Example 1] Coupler emulsion B of Example 1
In the preparation method described above, the above-mentioned exemplified compound (C-
2) Instead of 4.0 g, the following coupler (coupler 2)
A thermosensitive recording material (3) was obtained in the same manner as in Example 1 except that 6.0 g of the thermosensitive recording material was used.

[0145]

Embedded image

[Comparative Example 2] Coupler emulsion B of Example 1
In the preparation method described above, the above-mentioned exemplified compound (C-
2) Instead of 4.0 g, the following coupler (coupler 3)
A thermosensitive recording material (4) was obtained in the same manner as in Example 1 except that 4.8 g was used.

[0147]

Embedded image

[Evaluation of Thermosensitive Recording Material] The thermosensitive recording materials obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated by the following methods. Evaluation (1) (Yellow color density) The obtained material was subjected to 120 mJ per unit area using a KST type thermal head (manufactured by Kyocera Corporation).
The applied voltage and the pulse width to the thermal head were determined so that the recording energy became / mm ² , and an image was recorded.
The printed portion was measured for yellow density using a Macbeth RD-918 densitometer. Evaluation (2) (Hue as yellow) The sample printed in evaluation (1) was visually evaluated for the hue as yellow. Evaluation (3) (Fog of Unprinted Area) After the obtained heat-sensitive recording material (unprinted area) was stored at 60 ° C. and 30% RH for 24 hours, the fog was measured using the Macbeth RD-918 densitometer. evaluated. Evaluation (4) (Light fastness of image portion) The obtained thermal recording material was adjusted in recording energy of the thermal head, and a solid print sample corresponding to a yellow density of 1.0 was obtained from Weather /
Light was irradiated for 8 hours with an o-meter (Xe lamp), and the yellow density thereafter was measured again.

(Evaluation Results) The obtained results are summarized in Table 1.

[0150]

[Table 1]

From the results shown in Table 1, the heat-sensitive recording materials of the examples have a high color density and a bright yellow hue. Further, it can be seen that, even if left under the severe conditions of 60 ° C. and 30%, fog is minimized and the light resistance of the image portion is good.

[0152]

The heat-sensitive recording material of the present invention has a high coloring density as yellow, has a good hue, minimizes fogging even in an environment of high temperature and high humidity, and has a good light fastness of an image area. It is possible to provide a material having both color developability and preservability, which is an excellent material.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kiminori Nomura 200 Fujinaka Film Co., Ltd., Fujinomiya City, Shizuoka Prefecture (72) Inventor Satoshi Higuchi 200 Onakazato Fujinaka City, Fujinomiya City, Shizuoka Prefecture Fuji Photo Film Co., Ltd. (72) Inventor Katsuya Takemasa 200, Onakazato, Fujinomiya-shi, Shizuoka Prefecture F-film F-term (reference) 2H026 AA07 BB42 BB43 DD02 DD15 DD23 DD46 DD53 FF05

Claims (6)

[Claims] 1. A thermosensitive recording material comprising at least one diazo compound on a support and at least one coupler which forms a color by reacting with the diazo compound, wherein at least one compound of the following general formula (1) is used as a coupler: Thermal recording material containing Embedded image In the formula, R ¹ represents a hydrogen atom, an alkyl group, an aryl group,
R ² represents a hydrogen atom, an alkyl group, or an aryl group. However, ^one of R ¹ and R ² represents an aryl group. 2. A thermosensitive recording material comprising at least one diazo compound on a support and at least one coupler which forms a color by reacting with the diazo compound, wherein at least one compound of the following general formula (2) is used as the coupler: The heat-sensitive recording material according to claim 1, further comprising: Embedded image In the formula, R ¹ represents a hydrogen atom, an alkyl group, an aryl group,
R ³ , R ⁴ , R ⁵ , R ⁶ , and R ⁷ each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, Carbonyl group, aryloxycarbonyl group, acyloxy group, acyl group, carbamoyl group, acylamino group,
Represents a sulfamoyl group, a sulfonamide group, or a cyano group. 3. A thermosensitive recording material comprising at least one diazo compound and at least one coupler which forms a color by reacting with the diazo compound on a support, wherein at least one of the compounds represented by the following general formula (3) is used as the diazo compound. 3. The heat-sensitive recording material according to claim 1, which contains one kind. Embedded image In the formula, R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ are each a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group,
Alkoxycarbonyl group, an aryloxycarbonyl group, represents an acyloxy group, an acyl group, a carbamoyl group, an acylamino group, a sulfamoyl group, a sulfonamido group, a cyano group, any group selected from a nitro group, R ⁵⁵ is an alkyl group, an aryl Represents a group. 4. A thermosensitive recording material comprising at least one diazo compound and at least one coupler which reacts with the diazo compound to form a color on a support, wherein the diazo compound is encapsulated in microcapsules. The heat-sensitive recording material according to any one of claims 1 to 3, wherein 5. The heat-sensitive recording material according to claim 1, further comprising an organic base. 6. The heat-sensitive recording material according to claim 4, wherein the capsule wall forming the microcapsules contains urethane and / or urea as constituents.