JPH0245189A - Recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material capable of obtaining an yellow image which is high in color density, excellent in light fastness and quick in coloring speed by a method wherein a specific leuco coloring matter is contained in a recording material. CONSTITUTION:A recording material contains leuco coloring matter given in the formula. A use amount of this leuco color matter is preferably within a range of 0.01 to 1 g/m<2>. For this recording material, the leuco color matter and acid developer such as acid clay series or the like are contained in a microcapsule to be coexisted in a recording layer. Otherwise, the leuco color matter and the developer are separated, are pressurized and/or heated when an image is formed, and both are brough into contact with each other to be used. In the formula, R<1>, R<2> express alkyl radical, cycloalkyl radical or aryl radical and further, R expresses hydrogen atom, halogen atom, substituted or un- substituted alkyl radical, and aryl radical. R expresses substituted or un- substituted aryl radical or heterocyclic radial, and R expresses hydrogen atom, halogen atom, cyano radical, alkyl radical, etc., (n) expresses natural number of 1 to 5.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to recording materials such as pressure-sensitive recording materials, heat-sensitive recording materials, and photosensitive recording materials. The present invention relates to a recording material containing a leuco dye.

"Prior Art" It has been known that leuco dyes, also called reduced dyes, exhibit a coloring reaction when in contact with acidic substances (9 coloring agents) and can be easily obtained as color images. These dyes are widely used as color image forming substances in various recording materials such as heat-sensitive, pressure-sensitive or photosensitive recording materials.

Generally, leuco dyes are contained in the recording layer in a state separated from the above-mentioned acidic substances using a method such as microencapsulation, and then applied with external energy such as pressure and/or heating when used. It is used by destroying the capsule and bringing the two into contact.

"Problems to be Solved by the Invention" Among leuco dyes, compounds that develop a particularly yellow color include, for example, Japanese Patent Publication No. 45-4698 and Japanese Patent Application Laid-open No. 49-1989.
No. 4480, Special Publication No. 50-24646, No. 51-27
There are descriptions in various publications such as No. 169 and No. 53-9127. However, when these dyes were used, high color development was not necessarily obtained. In addition, although an image can be obtained by developing color, the color gradually fades and the image becomes unclear.

``Object of the Invention'' An object of the present invention is to provide a recording material from which a yellow image with high color density and excellent light resistance can be obtained. Another object of the present invention is to provide a recording material capable of producing a yellow image with a high color development speed.

In particular, the present invention aims to provide a recording material containing a yellow image forming substance (leuco dye).

"Means for Solving the Problems" That is, the present invention resides in a recording material containing a novel leuco dye having a moiety represented by the following general formula [I].

General formula (1) However, in the above general formula (1), R1 and R2 may be the same or different and represent a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group, and R1 and R2 are carbon R3 may be linked through atoms or heteroatoms to form a ring; R3 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an aryl group, an alkoxy group, or an aryloxy group; R4 represents a substituted or unsubstituted alkyl group; Represents an aryl group or a heterocyclic group, R5 is a hydrogen atom, a halogen atom, an acetoxy group, a carbonyl group, a substituted carbamoyl group, a substituted sulfamoyl group, a sulfonylamino group, an acydiamino group, an amino group, a hydroxyl group, a nitro group, a cyano group , substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkoxy group, aryloxy group, alkylsulfonyl group,
Roxy represents a carbonyl group, an alkylsulfonyl group or an arylsulfonyl group, n represents a natural number of 1 to 5, and when n is 2 to 5, R5 may be the same or different, and the general formula A multimer may be formed by the portion (1).

Furthermore, the general formula (+) will be explained in detail.

The alkyl group represented by the above general formula (1), RI SRt , R3 and R5 has 1 to 1 carbon atoms.
It is preferably 22 (more preferably 1 to 12). These may have a linear structure or have a branch, and may be substituted with a substituent such as a halogen atom, a phenyl group, an alkoxy group, or a hydroxyl group.

Examples of the cycloalkyl group represented by R1 and R2 include a cyclopentyl group, a cyclohexyl group, a cyclohebutyl group, and a cyclooctyl group. Further, these may be substituted with a halogen atom, a phenyl group, an alkoxy group, a hydroxyl group, a cyano group, or the like.

Examples of the aryl group represented by R', R'', R'', R' and R5 include phenyl group, naphthyl group, anthracenyl group, phenacitrenyl group, etc., but preferred are phenyl group and naphthyl group. be. In addition, these include alkyl groups, aryl groups, halogen atoms, alkoxy groups, aryloxy groups, alkoxycarbonyl groups, aryloxycarbonyl groups, amide groups, sulfonyl groups, carboxyl groups, carbonyl groups,
It may be substituted with a hydroxyl group, cyano group, nitro group, amino group, carbamoyl group, sulfamoyl group, etc.

Specific examples of the ring when R1 and R1 form a ring include a pyrrolidine ring, an imidazolidine ring, a virol ring, a piperidine ring, a morpholine ring, an indole ring, a carbazole ring, and an indoline ring.

The alkyl portion of the alkoxy group represented by R3 and RS has the same meaning as the alkyl group and cycloalkyl group described for R1 and R1, and the same applies to the substituents.

The aryl portion of the aryloxy group represented by R3 and R5 has the same meaning as the aryl group described for R1, R1, R2, R4 and R8, and the same applies to the substituents.

The halogen atoms represented by R3 and R5 are fluorine,
It refers to chlorine, bromine, and iodine atoms, but the preferred ones are:
Fluorine and chlorine atoms.

Examples of the heterocyclic group represented by R4 include a pyridyl group, a pyrimidyl group, an imidazolyl group, a thiazolyl group, a succinimide group, and a hidacytoinyl group. These may form a condensed ring with a benzene ring, a naphthalene ring, etc., and when forming a condensed ring, the partner to which the condensed ring is bonded may be a heterocycle, and the benzene ring, naphthalene ring, etc. In addition, the heterocyclic group represented by R4 may be a halogen atom, an alkyl group or alkoxy group having 1 to 10 carbon atoms, or a nitro group, etc.
may have been done.

The acetoxy group represented by R' represents a substituent represented by the general formula -OCR'. However, R1 is represented by the above general formula (1
) R1. It has the same meaning as R1, and the same applies to its substituents.

The carbonyl group represented by R5 represents a substituent represented by the general formula -CR', provided that R? has the same meaning as R' mentioned in the explanation of the acetoxy group, and the same applies to its substituents.

An example of the substituent of the substituted carbamoyl group and substituted sulfamoyl group represented by RS is an aryl group. This aryl group is RI SRt ,
It has the same meaning as the aryl group described for R2 and R5, and the same applies to its substituents.

The alkyl moiety of the alkoxycarbonyl group and alkylsulfonyl group represented by R5 has the same meaning as the alkyl group described above, and the same applies to its substituents.

The aryloxycarbonyl group represented by R5,
The aryl portion of the rusulfonyl group has the same meaning as the above-mentioned aryl group, and the same applies to its substituents.

The sulfonylamino group represented by R% has the general formula -NS
Indicates a substituent represented by ozR', provided that R7 is R? as described in the explanation of acetoxy. and the same applies to its substituents. R11 is a hydrogen atom, an alkyl group (
Same meaning as above. ) or an aryl group (synonymous with the above).

The acylamino group represented by R5 has the general formula -NCOR
represents a substituent represented by ', provided that R' and R'' have the same meanings as R? and R1 described in the explanation of the sulfonylamino group, and the same applies to the substituent.

The amino group represented by R5 has the general formula -NCR'').

0m represents a natural number 1 or 2, and m is 2. In this case, R@ may be the same or different.

Moreover, in the above (R'), n represents a natural number of 1 to 5, and when n is 2 to 5, Rs may be the same or different.

Further, the multimer is a dimer or more and is not particularly limited.

The leuco dye of the present invention is preferably a compound further containing a moiety represented by the following general formula (II).

General formula (n) (l (13) in the above formula, RI I, R''% RIS, RI & may be the same or different and represent a substituted or unsubstituted alkyl group, cycloalkyl group or aryl group,
RI4 represents a substituted or unsubstituted aryl group or heterocyclic group; RIS represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, or an aryl group; l represents a natural number from 1 to 4; , when i is 2 to 4, RIS may be the same or different,
Further, R11 and RIS may be linked through a carbon atom or a heteroatom to form a ring, and a multimer may be formed by the moiety of the general formula [■].

In the above formula, R eyes, RIS, R13, RIS and R
The alkyl group represented by lth has 1 to 2 carbon atoms.
2 (more preferably 1 to 12),
These may have a linear structure or a branched structure, and may be a substituent such as a halogen atom, an aryl group (such as a phenyl group or a naphthyl group), a heterocyclic group, an alkoxy group, or a hydroxyl group. May be replaced.

Examples of the cycloalkyl group represented by R'' and the R group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. It may be substituted with a group or a cyano group.

Examples of the aryl group represented by R, R1-rich, R1-rich, R14, RIS, and RC6 include phenyl, naphthyl, anthracenyl, and phenacitrenyl groups, with phenyl and naphthyl groups being preferred. be. In addition, these include an alkyl group, an aryl group, a halogen atom, an alkoxy group, an aryoloxy group,
It may be substituted with an alkoxycarbonyl group, an aryloxycarbonyl group, an amide group, a sulfonyl group, a carboxyl group, a carbonyl group, a hydroxyl group, a cyano group, a nitro group, an amino group, a carbamoyl group, a sulfamoyl group, or the like.

Examples of the heterocyclic group represented by RI4 include pyridyl group, pyrimidyl group, imidazolyl group, thiazolyl group,
Examples include a succinimide group and a hydacytoinyl group. These may form a condensed ring with a benzene ring, a naphthalene ring, etc. The heterocyclic group represented by R14 may have a structure bonded to a ring or the like, and may be substituted with a halogen atom, an alkyl group or alkoxy group having 1 to 10 carbon atoms, a nitro group, or the like.

The halogen atom represented by RIB refers to fluorine, chlorine, bromine, and iodine atoms, with fluorine and chlorine atoms being preferred.

Further, in the above formula (Rls), l represents a natural number from 1 to 4, and when l is 2 to 4, each Rs may be the same or different.

A specific example of the case where RI I and RIB form a ring includes a ring formed by R1 and R2 in general formula (1).

Next, typical examples of leuco dyes that can be used in the recording material of the present invention will be shown, but the invention is not limited thereto.

tHs tHs Js zHS tHs C18゜ zHs C! H.S. 0υ CJ, +(n) Js C,H.

α (Foundation) tos tHs zus zos C Spirit US tHs C,H.

l1ff CJ(+5(n) C10゜ C,H.

zus c, n.

C! 11.

tHs Gi C,H.

zHs The amount of the leuco dye used in the present invention is not particularly limited, but it is preferably used in the range of 0.01 to Ig, particularly preferably in the range of 0.03 to 0.3 g.

The leuco dye used in the present invention can be prepared by the method shown below.
Can be easily synthesized.

(Synthesis Example 1) Leuco color (11 people 2-(4-diethylamino-2-methoxybenzoyl)
5.00 g of -benzoic acid was dissolved in 25-N,N-dimethylacetamide, and 1.34-g of thionyl chloride was added dropwise over 1 minute while stirring and cooling in an ice water bath. After cooling and stirring for 20 minutes, 1.81 g of p-aminobenzonitrile was added, and the mixture was cooled and stirred for an additional 30 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N-dimethylacetamide 25-,
1.9 (ld) of methyl iodide and 4.23 g of potassium carbonate were added, and the reaction mixture was stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was removed. Evaporation gave a yellow oil. Crystallization from methanol yielded 4.80 g of the desired leuco dye.
was obtained as pale yellow crystals with a melting point of 126-128°C.

(Synthesis Example 2) 2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, 1.34 d of thionyl chloride was added dropwise over 2 minutes. After cooling and stirring for 20 minutes, 2.31 g of methyl anthranilate was added,
The reaction mixture was further cooled and stirred for 20 minutes, then poured onto water.
Extracted with ethyl acetate. After washing the organic layer with water and drying,
Evaporation of the solvent gave a yellow oil. This is N,
Dissolved in 25M1 of N-dimethylacetamide, added 1.86Wl of methyl iodide and 4.23g of potassium carbonate,
The reaction mixture was stirred at room temperature for 1 hour, poured onto water, and extracted with ethyl acetate. The organic layer was washed with water, dried and the solvent was evaporated to give a yellow oil. Purification was performed by silica gel column chromatography to obtain 4.70 g of the desired leuco dye (2) as a yellow oil.

(Synthesis Example 3) 2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, thionyl chloride 1.34- was added dropwise over 1 minute. After cooling and stirring for 20 minutes, 2.29 g of 3,4-dicyanoaniline was added, and the reaction mixture was further cooled and stirred for 15 minutes, poured onto water, and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N-dimethylacetamide 25-,
1.86 ml of methyl iodide and 4.23 g of potassium carbonate were added and stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. Crystallization from methanol yields the desired leuco dye+315. OO
g was obtained as yellow crystals with a melting point of 123-126°C.

(Synthesis Example 4) (2) Synthesis of 2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, thionyl chloride 1.34- was added dropwise over 1 minute. After cooling and stirring for 20 minutes, 1.81 g of 0-aminobenzonitrile was added, and the mixture was cooled and stirred for an additional 30 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N-dimethylacetamide 25-,
1.90 ml of methyl iodide and 4.23 g of potassium carbonate were added and stirred at room temperature for 2 hours. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. Crystallization is performed from methanol to obtain the desired leuco dye (41, 4, 8
5 g was obtained as pale yellow crystals with a melting point of 131-134°C.
.

(Synthesis Example 5) Dando Yumu Momitatetateso 2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, thionyl chloride 1.34- was added dropwise over 1 minute. After cooling and stirring for 15 minutes, 2.53 g of ethyl p-aminobenzoate was added, and the mixture was further cooled and stirred for 20 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N dimethylacetamide 25-,
1.9 of methyl iodide and 4.23 g of potassium carbonate were added and stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried and the solvent was evaporated to give a yellow oil. Purification was performed by silica gel column chromatography to obtain a pale yellow oil. Crystallize from methanol to obtain 516.17 g of the desired leuco dye with a melting point of 87.0-89.0°C.
Obtained as pale yellow crystals.

(Synthesis Example 6) 2-(4-diethylamino-2-methoxybenzoyl)
- Benzoin fII5. OOg was dissolved in N,N-dimethylacetamide 25H&, while cooling and stirring in an ice water bath.
1.34 ml of thionyl chloride was added dropwise over 2 minutes. 10
After cooling and stirring for a minute, 1.95 g of m-chloroaniline was added, and the mixture was cooled and stirred for an additional 10 minutes.The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. This was dissolved in N,N-dimethylacetamide 15-, 0.792 m of methyl iodide and 1.76 g of potassium carbonate were added, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to yield a yellow oil. Purification was performed by silica gel column chromatography to obtain +612.07 g of the desired leuco dye as a yellow oil.

(Synthesis Example 7) Dan Eyumu element! Rikkiso 2-(4-di-n-butylamino-2-n-butoxybenzoyl)benzoic acid 10. Ogwon was dissolved in 50 d of N-dimethylacetamide, and while cooling and stirring in an ice water bath, 2.06 ml of thionyl chloride was added dropwise over 2 minutes. After cooling and stirring for 10 minutes, 4.61 g of 2-cyano-4-methylsulfonylaniline was added over 2 minutes, and
The mixture was cooled and stirred for 0 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried and the solvent was evaporated to give a yellow oil. This is N.

N-dimethylacetamide 5 (1d) was dissolved, 2.20 d of methyl iodide and 4.89 g of potassium carbonate were added, and the mixture was heated and stirred on a steam bath for 10 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate.

The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow-red oil. Crystallization was performed from methanol to obtain 8.49 g of the desired leuco dye QI as yellow crystals with a melting point of 147-150°C.

(Synthesis example day) Leuco Qll person 2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, thionyl chloride 1.34- was added dropwise over 1 minute. After cooling and stirring for 20 minutes, p-isopropylsulfonylaniline 3.0
5 g was added, and the mixture was further cooled and stirred for 15 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. Wash the organic layer with water,
After drying, evaporation of the solvent gave a yellow oil. This was dissolved in 25 M1 of N,N-dimethylacetamide, 1.9 (ld) of methyl iodide, 4.2 ml of potassium carbonate.
The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to yield a yellow oil. Purification was performed by silica gel column chromatography to obtain 6.43 g of the target leuco dye αD as a yellow oil.

(Synthesis Example 9) YuAj'101 錦剦2-(4-diethylamino-2-methoxybenzoyl)
-benzoic acid5. OOg was dissolved in N,N-dimethylacetamide 25-, and while cooling and stirring in an ice water bath, thionyl chloride 1.34- was added dropwise over 2 minutes. After cooling and stirring for 20 minutes, 2.11 g of m-nitroaniline was added, and the mixture was cooled and stirred for an additional 15 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. This is N, N
The reaction mixture was dissolved in -dimethylacetamide 25-, 1.86 m of methyl iodide and 4.23 g of potassium carbonate were added, and stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. Purification was performed by silica gel column chromatography to obtain 34.33 g of the target leuco dye α as a yellow oil.

(Synthesis Example 10) 2-(4-diethylamino-2-methoxybenzoyl)
-5.00 g of benzoic acid was dissolved in N,N-dimethylacetamide 25-, and 1.34 m of thionyl chloride was added dropwise over 1 minute while cooling and stirring in an ice water bath. After cooling and stirring for 15 minutes, 1.81 g of p-aminobenzonitrile was added, and the mixture was further cooled and stirred for 20 minutes. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N-dimethylacetodoamide 25-, and 1.65 g of 1,4-dibromoethane and 4 potassium carbonate were added.
．． The reaction mixture was poured onto water and extracted with ethyl acetate. Wash the organic layer with water,
After drying, evaporation of the solvent gave a yellow oil. Crystallize from methanol to obtain the desired leuco dye α
15.20 g were obtained as yellow crystals with a melting point of 164-166°C.

(Synthesis Example 11) Leuco, al's 2-(4-diethylamino-2-methoxybenzoyl)
- 5.00 g of benzoic acid was dissolved in N,N-dimethylacetamide 25-, and thionyl chloride 1.34- was added dropwise over 1 minute while stirring and cooling in an ice water bath. After cooling and stirring for 20 minutes, 1.53 g of 2-aminothiazole was added,
The reaction mixture was further cooled and stirred for 30 minutes, then poured onto water.
Extracted with ethyl acetate. After washing the organic layer with water and drying,
Evaporation of the solvent gave a yellow oil. This is N,
The reaction mixture was dissolved in N-dimethylacetamide 25-, added with 1.9 (ld) methyl iodide and 4.23 g of potassium carbonate, and stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer After washing with water and drying, the solvent was evaporated to obtain a yellow oil. Purification was performed by silica gel column chromatography to obtain 14.21 g of the desired leuco dye α as a yellow oil.

(Synthesis Example 12) Leuco (21 people) 7.00 g of 2-(4-diethylamino-2-benzyloxybenzoyl)-benzoic acid was dissolved in 351 d of N,N-dimethylacetamide, and while cooling and stirring in an ice water bath, 1.52% of thionyl chloride was added dropwise over 1 minute.2
After cooling and stirring for 0 minutes, 2.04 g of p-aminobenzonitrile
was added and cooled for further 20 minutes.Pi1. The stirred reaction mixture was poured onto water and extracted with ethyl acetate. After washing the organic layer with water and drying, the solvent was removed once to obtain a yellow oil. This was dissolved in N,N-dimethylacetamide 35-2.15M methyl iodide! , potassium carbonate 4.7
8 g was added and stirred at room temperature for 1 hour.

The reaction mixture was poured onto water and extracted with ethyl acetate.

The organic layer was washed with water, dried, and the solvent was evaporated to give yellow-red crystals. Recrystallize from methanol to obtain 6.80 g of the desired leuco dye (total) with a melting point of 169-170.
Obtained as pale yellow crystals at ℃.

(Synthesis Example 13) Leuco dye (23-2-(4-diethylamino-2-methoxybenzoyl))
5.00 g of -benzoic acid was dissolved in 25-N,N-dimethylacetamide, and 1.34-g of thionyl chloride was added dropwise over 2 minutes while stirring and cooling in an ice water bath. After stirring for 20 minutes, 2.19 g of 3,4-dicyanoaniline was added, and the mixture was cooled and stirred for an additional 15 minutes.The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. This is N
, dissolved in 25 ad of N-dimethylacetamide, added 5.23 g of benzyl bromide, 4.23 g of potassium carbonate,
The reaction mixture was stirred at room temperature for 1.5 hours and poured onto water.
Extracted with ethyl acetate. After washing the organic layer with water and drying,
Evaporation of the solvent gave a yellow oil. Purification was performed by silica gel column chromatography to obtain 8.49 g of the desired leuco dye (23) as a yellow oil.

(Synthesis Example 14) Leuco color: Dissolve 6.00 g of 2-(4-ethyltolylamino-2-methoxybenzoyl)-benzoic acid of (27) in 30-N,N-dimethylacetamide and cool in an ice-water bath. While stirring, 1.35% of thionyl chloride was added dropwise over 2 minutes. After cooling and stirring for 30 minutes, 2.27 g of methyl anthranilate was added, and the mixture was further cooled and stirred for 60 minutes.The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil.

This was dissolved in N,N-dimethylacetamide 30-,
1.90 ml of methyl iodide and 4.14 g of potassium carbonate were added and stirred at room temperature for 1 hour. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a yellow oil. Purification was performed by silica gel column chromatography to obtain 5.10 g of the desired leuco dye (27) as a yellow oil.

(Synthesis Example 15) Leuco color (37) Mu4-diethylamino-2-methoxybenzophenone 10
．． 0 g, methyl anthranilate 5.33 g, p-toluenesulfonic acid hydrate 1. OOg was dispersed in xylene 100g and refluxed for 20 hours using a Tienstak apparatus while separating the produced water. The reaction mixture was poured onto water and extracted with ethyl acetate. Wash the organic layer with water,
After drying, evaporation of the solvent gave a brown oil.

Purified by silica gel column chromatography,
Target leuco dye (37) 2. Obtained 55 g as a pale yellow oil.

(Synthesis Example 16) Leuco color (38) 4-diethylamino-2-methoxybenzophenone to
, og, p-aminobenzoate isobutyl 6.82 g, p
-) 1°00g of luenesulfonic acid hydrate and 1xylene
00- and refluxed for 24 hours using a Tienstag apparatus while separating the water produced. The reaction mixture was poured onto water and extracted with ethyl acetate. The organic layer was washed with water, dried, and the solvent was evaporated to give a brown oil. Purification was performed by silica gel column chromatography to obtain 2.76 g of the desired leuco dye (38) as a yellow oil.

The recording material of the present invention has the general formula [! The recording layer contains leuco dyes represented by the following, either alone or in an appropriate mixture. In addition, the leuco dye according to the present invention and one or more other known leuco dyes having the same or different color hue may be used in combination. By doing this, various color images can be obtained. Examples of known leuco dyes include the aforementioned triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, spiro compounds, and mixtures thereof.

In the recording material of the present invention, the leuco dye and the acidic color developer described below are separated, and the two are brought into contact with each other during image formation. The leuco dye and the color developer are separated by a method such as storing the leuco dye and the color developer together in the recording layer, or including the leuco dye and the color developer in separate layers. The two are used by bringing them into contact by applying pressure and/or heating. Alternatively, the leuco dye and the color developer may be contained in separate materials (for example, a material containing the leuco dye and a material containing the color developer) and then separated, and then combined and processed during image formation. The two are used by bringing them into contact by applying pressure and/or heat. In this case, the acidic color developer may be contained in a microcapsule separate from the microcapsule containing the leuco dye and may be present in the same layer or in a separate layer.

In particular, when forming an image using a pressure-sensitive recording material or a photosensitive recording material among the recording materials of the present invention, the above-mentioned leuco dye is microencapsulated and contained in the recording layer, while an acidic color developer is It is preferable to use an embodiment in which the colorant is contained in another material (for example, a color developer sheet or an image-receiving material).

By adopting the above usage mode, the sensitivity and sharpness of the color image obtained can be improved.

In the above color development reaction, it is preferable to bring the leuco dye and the color developer into contact under heating conditions.Heating can significantly accelerate the above color development reaction.

The heating temperature is generally 50°C to 200°C, preferably 50°C to 150°C. The heating time is generally 1
The time period is from 1 second to 1 minute, preferably from 1 second to 10 seconds.

Examples of the acidic color developer mentioned above include acidic clay color developer (
clay), phenol-formaldehyde resin <L
p-phenylphenol-formaldehyde resin),
Metal salts of salicylic acids (e.g., zinc 3,5-di-α-methylbenzylsalicylate), phenol-salicylic acid-formaldehyde resin (e.g., p-octylphenol-
Zinc salicylate-formaldehyde resin), zinc rhodan, zinc xanthate, and the like.

Among these acidic color developers, the color developer that can be used in the present invention is Salicyl T! 1. A metal salt of m is preferable, and a zinc salicylate color developer is particularly preferable.That is, according to the research of the present inventors, the coloring reaction of the leu-co dye occurs rapidly in the presence of a zinc salicylate color developer. It has become clear that the process progresses efficiently. Details of metal salts of salicylic acids can be found in, for example, Japanese Patent Publication No. 1327/1983. Note that oil-soluble zinc salts of salicylic acid are described in US Pat. No. 3,864,146 and US Pat. No. 4,046,941.

The acidic color developer mentioned above has a negative effect on leuco dyes.
It is preferably used in a range of 50 to 1000% by weight, and more preferably in a range of 100 to 1000% by weight.

The leuco dye according to the present invention can be applied to any recording material, such as a pressure-sensitive recording material, a heat-sensitive recording material, or a photosensitive recording material.

Among recording materials, the present invention will be explained in more detail by taking pressure-sensitive recording materials and heat-sensitive recording materials as examples.

A pressure-sensitive recording material (sheet) generally comprises a color former-containing sheet (hereinafter referred to as a color former sheet) containing a color former containing at least one of the leuco dyes according to the present invention, and a color developer described above. The color developer side containing sheet (hereinafter referred to as color developer sheet) is composed of -m material (sheet). The color former sheet is made up of a support and a layer containing a color former provided thereon, and the color developer sheet is made up of a support and a layer containing a color former provided thereon.
Each layer is composed of a layer containing a color developer provided thereon.

A layer containing a color former can be formed on a support as follows.

The layer containing a color former is a layer in which the color former is contained and supported in a dispersed state by a binder.

The coloring agent containing the leuco dye is preferably in the form of microcapsules.

Microcapsules can be formed, for example, by the following method.

After the above-mentioned color former is dissolved or dispersed in a suitable organic solvent, this solution or dispersion (oil-based liquid) is emulsified and dispersed in an aqueous medium.

If an organic solvent with a low boiling point is used, there will be evaporation loss during storage, so it is preferable to use one with a boiling point of 180°C or higher.As the organic solvent/vehicle, phosphate ester, phthalate ester, etc. carboxylic acid esters, fatty acid amides, alkylated hypohenyls, alkylated terphenyls, chlorinated paraffins, alkylated naphthalenes, diarylethanes, etc. are used.

Specific examples include tricresyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, tricyclohexyl phosphate, dibutyl phthalate, dioctyl phthalate,
Dilauryl phthalate, dicyclohexyl phthalate, butyl oleate, diethylene glycol dibenzoate,
Dioctyl sebacate, diptyl sebacate, dioctyl adipate, trioctyl trimellitate, acetyltriethyl citrate, octyl maleate, dibutyl maleate, isopropylbiphenyl, isoamyl biphenyl, chlorinated paraffin, diisopropylnaphthalene,
1.1'-ditolylethane, 2.4-ditert-
Amylphenol, N,N-dibutyl-2-butoxy-
5-tert-octylaniline is mentioned. In addition to these, vinyl compounds can also be used as suitable organic solvents.

The leuco dye according to the present invention is preferably used in an amount of 2 to 20% by weight based on the organic solvent.

Next, a capsule wall made of a polymer material is formed around the emulsified and dispersed oil droplets.

There are no particular restrictions on the polymeric material that forms the capsule wall; examples thereof include polyurethane, polyurea, polyamide, polyester, urea/formaldehyde resin, melamine resin, polystyrene, styrene/methacrylate copolymer, and styrene/acrylate copolymer. Mention may be made of polymers and mixed systems thereof.

The microcapsule formation method is not particularly limited and any known method can be used, but interfacial polymerization and internal polymerization are preferred in the present invention.

For example, when polyurea polyurethane is used as a capsule wall material, a polyisocyanate and a second substance (e.g., polyol, polyamine) that reacts with it to form the capsule wall are mixed into an aqueous medium or an oily liquid to be encapsulated. By emulsifying and dispersing these in water and then heating them, a polymer formation reaction occurs at the oil droplet interface and a microcapsule wall is formed.

Furthermore, when forming microcapsules, a water-soluble polymer compound can be used as a protective colloid. Examples of the water-soluble polymer compound include water-soluble anionic polymer compounds, nonionic polymer compounds, and amphoteric polymer compounds.

The anionic polymer compound may be a natural substance or a synthetic substance, and includes, for example, those having carboxyl groups, sulfonic acid groups, etc. Specific examples include anionic natural polymer compounds such as gum arabic and alginic acid; carboxymethyl cellulose, phthalated gelatin, sulfated starch,
Semi-synthetic polymer compounds such as sulfated cellulose and ligninsulfonic acid; and maleic anhydride (including hydrolyzed) copolymers, (meth)acrylic acid polymers and copolymers, and vinylbenzenesulfonic acid. Synthetic polymer compounds include polymers, copolymers, and carboxy-modified polyvinyl alcohol. Specific examples of nonionic polymer compounds include polyvinyl alcohol, hydroxyethyl cellulose, and methylcellulose. Specific examples of amphoteric polymer compounds include gelatin.

These water-soluble polymer compounds have a molecular weight of 0.01 to 1O! 11
% aqueous solution.

Examples of binders used in layers containing color formers include polyvinyl alcohol, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, gum arabic, gelatin, polyvinylpyrrolidone, casein,
Styrene/butadiene latex, acrylonitrile/
Mention may be made of butadiene latex, polyvinyl acetate, polyacrylic ester and nyletine-vinyl acetate copolymer, and these compounds are used in the form of various emulsions.

The amount of binder used ranges from 0.5 to 5 g/cd solids.

The layer containing the coloring agent is prepared by mixing the liquid containing the microcapsules and the binder solution to prepare a coating liquid, and then applying this coating liquid by a conventional coating method such as bar coating, blade coating, or air knife coating. It can be formed by coating on a support by a coating method such as coating, gravure coating, roll coating, spray coating, or dip coating, and drying.

The layer containing the coloring agent is usually provided with a solid content in the range of 2.5 to 25 g/d.

The support used in the present invention is usually paper. For example, as a paper support, thermal extraction pH 6 to 6 is sized with a neutral sizing agent such as alkyl ketene dimer.
Neutral paper No. 9 (described in JP-A-55-14281) is preferred from the viewpoint of long-term storage stability.These may be appropriately surface-treated.

On the other hand, for the layer containing the color developer, prepare a coating solution by mixing the binder used above with the emulsion containing the color developer prepared above, and then apply this coating solution in the same manner as above. It can be formed by coating it on a support using a solvent and drying it. Note that paper is also suitably used as the support in the same manner as above.

A pressure-sensitive recording material (sheet) containing the leuco dye according to the present invention can be obtained by combining (bonding) the color former sheet obtained as described above and the color developer sheet.

The above-mentioned pressure-sensitive recording material is an example of an embodiment, and in addition to the above, for example, a color forming agent and a color developer may be contained in separate microcapsules in the same sheet (same layer). As mentioned above, the pressure-sensitive recording sheet may have a multilayer structure in which the color forming agent and the color developer are present in separate layers.

The recording method using the pressure-sensitive recording material of the present invention is carried out by applying external pressure to the recording paper, for example, from a pencil or a typewriter. That is, the microcapsules present in the area where the pressure is applied are destroyed, the color forming agent inside is released, and coloring occurs when this comes into contact with the adjacent color developing agent.

Next, the heat-sensitive recording material will be explained.

The structure of the heat-sensitive recording material can basically be the same as the structure of the pressure-sensitive recording material described above.

That is, the heat-sensitive recording material is composed of a support and a heat-sensitive recording layer provided thereon. The recording layer contains a coloring agent containing a leuco dye according to the present invention. However, from the viewpoint of thermal responsiveness and low thermal energy required for color development, it is preferable that the color developer is also present in the same layer. In this case, it is sufficient that the two are isolated within the layer, but it is preferable that the color former is microencapsulated using the above method and contained in the recording layer.

From this point of view, the microcapsule wall material is preferably a polymeric substance that is impermeable at room temperature and becomes permeable when heated, and in particular, one with a glass transition temperature of 60 to 200°C is preferable. Among the above wall materials, polyurea or polyurethane is particularly preferred.

Heat-sensitive recording on the heat-sensitive recording material of the present invention can be performed, for example, as follows.

First, the recording paper is placed so as to be in contact with a heating body (print head) such as a hot needle or a thermal head.

This heating element is heated in a time-series manner in response to electrical signals containing image information sent from a facsimile machine, computer, etc., and at the same time scans one side of the recording paper while in contact with the recording paper. On the other hand, by moving the recording paper in a direction perpendicular to the scanning direction of the heating element, it is possible to form a two-dimensional print or image on the recording paper.

As described above, typical recording materials of the present invention have been described. However, in addition to the above, the recording materials of the present invention include, for example, current-carrying heat-sensitive recording sheets, ultrasonic recording sheets, electron beam recording sheets, and electrostatic recording sheets. This also includes recording sheets.

Note that the above-mentioned photosensitive recording material includes a photosensitive recording material made of a photosensitive resin, such as a PS plate and a photoresist material.

In addition, photosensitive recording materials in which a polymerizable compound and a polymerization initiator are encapsulated in microcapsules (for example, JP-A-57-179
No. 836 and No. 57-197538), photosensitive recording materials having a photosensitive layer on a support comprising silver halide, a reducing agent, and a polymerizable compound (e.g., those described in JP-A No. 61-69062, No. 61-73145, No. 6
1-275742 and 61-278849) are also included. In this case, in case B of using the recording material, the leuco dye according to the present invention is contained in microcapsules together with a polymerizable compound and contained in the recording layer, while the color developer is contained in the image receiving material and exposed and developed. It is preferable to use both of them in a superimposed manner during image formation after processing.

"Effects of the Invention" By using the leuco dye (yellow image forming substance) represented by the above general formula (1) as a color image forming substance in the recording material, the coloring density is high, the coloring speed is fast, and further excellent light resistance is achieved. It is possible to obtain a color image with color characteristics.

In particular, when the above-mentioned leuco dye is used in a pressure-sensitive recording material, a photosensitive recording material, or a heat-sensitive recording material, remarkable effects can be obtained.

“Examples” The present invention will be explained in more detail with the following examples. However, the present invention is not limited thereto. In the examples, "part" means "1 part by weight" unless otherwise specified.

Example 1 [Creation of pressure-sensitive recording sheet] A pressure-sensitive recording sheet was created as follows.

Color Part of the sodium salt of polyvinylbenzenesulfonic acid in the sheet (product name, VER3A, TL500, average molecular fi: 500
, 000, manufactured by National Starch Co., Ltd.) was added to 95 parts of hot water at about 80° C. with stirring and dissolved therein. The sodium salt was dissolved in about 30 minutes and then cooled. The pH of the aqueous solution was 2 to 3, and a 20% by weight aqueous sodium hydroxide solution was added thereto to adjust the pH to 4.0.

On the other hand, the illustrated leuco color/particle (1) of the present invention [color former]
Diisopropylnaphthalene 10 dissolved in 3.5% by weight of
0 part was emulsified and dispersed in 100 parts of a 5% aqueous solution of a partial sodium salt of polyvinylbenzenesulfonic acid to obtain an emulsion having an average oil droplet size of 4.5 μm.

Separately, 6 parts of melamine, 11 parts of a 37% by weight formaldehyde aqueous solution, and 30 parts of water were heated to 60°C and stirred, and after 30 minutes, a transparent mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate (initial condensate solution) was prepared. Obtained. The pH of this mixed aqueous solution was 6-8.

Next, the initial condensate solution obtained by the above method was added to and mixed with the above emulsion, and the pH was adjusted to 6.0 with a 3.6% by weight phosphoric acid solution while stirring, and the liquid temperature was adjusted to 65°C. The mixture was raised to a high temperature and continued to be stirred for 6 hours to prepare a microcapsule dispersion. Further, this capsule dispersion was cooled to room temperature and adjusted to pH 9.0 with 20% by weight sodium hydroxide.

To this capsule dispersion, 200 parts of a 10% by weight polyvinyl alcohol (trade name, PVA-117, manufactured by Kuraray ■) aqueous solution and 50 parts of starch particles were added, and water was added to prepare a coating liquid with a solid content concentration of 20%. did. Then,
This coating liquid was coated on a 50 g/d base paper using an air knife coater so that the solid content was 5 glrd, and dried to prepare a coloring agent sheet.

Preparation of color developer sheet 3. Zinc 5-bis-α-methylbenzylsalicylate 10
2 parts of 1-isopropylphenyl-2-phenylethane
0 parts and heated and dissolved at 90°C. This was added to 50 parts of a 2% by weight polyvinyl alcohol (product name: PVA-117, manufactured by Kuraray ■) aqueous solution, and further added to a 10% aqueous solution of dodecylbenzenesulfonic acid triethanolamine salt [
30.1 parts of a surfactant was added and an emulsion having an average oil droplet size of 3 μm was prepared using a homogenizer.

Next, 80 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate, and 200 parts of water were dispersed using a Keddy mill to prepare a dispersion. After mixing the above emulsion with this, add 10% by weight as a binder.
100 parts of an aqueous solution of polyvinyl alcohol (product name: PVA-117, manufactured by Kuraray ■) and 10 parts of carboxy-modified SBR latex (trade name, 5N-307, manufactured by Sumitomo Nogatax ■) were added as a solid content to bring the solid content concentration to 20%. A coating solution (A) was prepared by adding water to the solution.

Separately, 10 parts of zinc 3.5-bis-α-methylbenzylsalicylate, 20 parts of Jilton clay, 6 parts of calcium carbonate.
0 parts, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate
A dispersion having an average particle size of 3 μm was prepared using a sand glider using 200 parts of water and 200 parts of water.

First, a 10% by weight polyvinyl alcohol (trade name 1PVA-103, manufactured by Kuraray ■) aqueous solution 1 was added to the obtained dispersion.
Next, 10 parts of a 10% polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray@) aqueous solution 10
0 parts and carboxy-modified SBR latex (as solid content)
Product name, SN-307, manufactured by Sumitomo Nogatasox ■) 1
A coating liquid (B) was prepared by adding 0 parts of the liquid and water so that the solid content concentration was 20%.

Coating liquid (A) and coating liquid (B) obtained above were mixed with A/B-50150 in terms of color developer, and 50 g/d of base paper was coated with 50 g/d.
．． A developer sheet was prepared by coating with an air knife coater so that a solid content of 0 g/- was applied and drying.

A pressure-sensitive recording sheet (I) was prepared by combining the color forming agent sheet and color developing agent sheet obtained as described above.

Examples 2 to 10 In Example 1, the leuco dye (
In place of 1), leuco dyes (2), (
3), (4), (5), On, (27), (33),
Example 1 except using (35) and (38)
Pressure-sensitive recording sheets (■) to (X) according to the present invention corresponding to each one were prepared by performing the same operations as described above.

Comparative Example 1 In Example 1, the leuco dye (
In place of 1), the corresponding pressure-sensitive recording sheets (X
r) and (■) were created.

Leuco dye (a) Leuco dye (b) [Evaluation of pressure-sensitive recording sheets] Each pressure-sensitive recording sheet (1) to (
Pressure was applied to XI), and the density of each yellow image obtained was measured using a reflection densitometer.

Next, each color image obtained above was subjected to a photofading test as described below to evaluate its light resistance.

The photofading test was conducted by irradiating the obtained color image with xenon light of aooooo lux for 3 hours, and then measuring the remaining density in the same manner as above. Note that the evaluation was expressed as the residual rate (%) of the color image after the previous color test.

The above measurement results are summarized in Table 1.

Table 1 As is clear from the results in Table 1, the pressure-sensitive recording sheets (I) to (X) containing the color forming agent of the present invention are different from the pressure-sensitive recording sheets (XI) containing the known leuco dye and It showed higher color density compared to (XI).

In addition, the color development rate was fast and excellent light resistance was exhibited.

Example 11 [Preparation of photosensitive material] Halogen Spirit Bud - Gelatin aqueous solution under stirring (gelatin 2 in 1000 d of water)
An aqueous solution 600WZ containing 21 g of sodium chloride and 56 g of potassium bromide and an aqueous silver nitrate solution (0.59 mole of silver nitrate dissolved in 600 - of water) were simultaneously added to Addition was made at equal flow rates over 40 minutes. In this way, a monodisperse cubic silver chlorobromide emulsion (80 mol % bromine) with an average grain size of 0.35 μm was prepared.

After washing the above emulsion with water and desalting it, sodium thiosulfate 5■ and 4-hydroxy-6-methyl-1゜3.3a, 7
Chemical sensitization was carried out at 60° C. by adding 20 μm of chitrazaindene. The yield of emulsion was 600 g.

28g of benzotriazole gelatin and 13.2g of benzotriazole to 33g of water
It was dissolved in 000d. This solution was stirred while keeping it at 40°C, and nitric acid 1117. A solution of 100g dissolved in 100ml of water was added over 2 minutes. Excess salt was precipitated and removed by adjusting the pH of the resulting emulsion. Then the pH was adjusted to 6.3.
0 to obtain a benzotriazole silver emulsion. The yield of emulsion was 400 g.

0.40 g of the following copolymer was added to 100 g of trimethylolpropane triacrylate, and the leuco dye of the present invention (
15.6 g of I and 2 g of Emmalex NP-8 (manufactured by Nippon Emulsion ■) were dissolved. Above solution 18. OO
A solution of 0.16 g of the following hydrazine derivative (reducing agent) and 1.22 g of the following developing agent (reducing agent) dissolved in 1.80 g of methylene chloride was added to g. Furthermore, 3.50 g of the silver halide emulsion prepared as above and 3.35 g of benzotriazole silver emulsion were added, and the mixture was stirred for 5 minutes at 15,000 revolutions per minute using a homogenizer to obtain a photosensitive composition. .

(copolymer) C) 13 + CHt-C+t.

CO□C4H9 (hydrazine derivative) Js (developer) 0 ■ 18.6% aqueous solution of isopane (manufactured by Kuraray ■) 10.51
g, add 48°56 g of a 2.89% aqueous solution of pectin,
Adjust the pH to 4.0 using 10% sulfuric acid. The above photosensitive composition was added to the aqueous solution adjusted to 0 and stirred for 2 minutes at 7000 rpm using a homogenizer to emulsify the above photosensitive composition in the aqueous solvent.

To 72.5 g of this aqueous emulsion, 8.32 g of urea 40% aqueous solution was added.
g, resorcinol 11.3% aqueous solution 2.82g, formalin 37% aqueous solution 8.56g, ammonium sulfate 8.76g
Add 2.74 g of g aqueous solution in sequence, 8! 60℃ while stirring
Heating was continued for 2 hours.

Thereafter, the pH was adjusted to 7.0 using a 10% aqueous sodium hydroxide solution, and 3.62 g of a 30.9% aqueous sodium bisulfite solution was added to prepare a microcapsule liquid.

10.0 g of microcapsule liquid prepared as above
1.0 g of a 1% aqueous solution of the following anionic surfactant, 10% guanidine trichloroacetate (water/ethanol-5
0150 volume ratio) solution was added and coated onto a 100 μm thick polyethylene terephthalate using a #40 coating rod and dried at about 40° C. to prepare a photosensitive material (A) according to the present invention.

(Anionic surfactant) CIIxCOOCL-CI (CtHs) CJvNa0s
S-CI-COOCHz-CH(CJs) CtH*Examples 12 to 22 In the preparation of the photosensitive composition of Example 11, the leuco dyes (2) and (3) of the present invention were used instead of the leuco dye (1).
), (4), (5), aη, (27), (33), (3
By operating in the same manner as in Example 11 except for using 5), (3 days), (41) and (42), corresponding photosensitive materials C'X II) according to the present invention were prepared.
~(XxXI) was produced.

Comparative Examples 2 to 3 In preparing the photosensitive composition of Example 11, the following leuco dyes (al and (bl) were used instead of leuco dye (11).
Corresponding photosensitive materials 0 &

Leuco dye (81 Leuco dye mountain) Add 11 g of 40% sodium hexametaphosphate aqueous solution to 125 g of water, and then mix with 34 g of zinc 3,5-di-α-methylbenzylsalicylate and 82 g of 55% calcium carbonate slurry. It was coarsely dispersed. The liquid was dispersed using a Dynamyl disperser, and 6 g of 50% SBR latex and 55 g of 8% polyvinyl alcohol were added to 200 g of the obtained liquid and mixed uniformly. This mixed solution was uniformly applied onto art paper weighing 43 g/rd to a wet film thickness of 30 μm, and then dried to prepare an image-receiving material.

[Evaluation of photosensitive materials]

Each of the photosensitive materials (XX■-)flV) obtained in Examples 11-22 and Comparative Examples 3-4 was evaluated by the following method.

Each photosensitive material was imagewise exposed for 1 second at 200 lux using a tungsten bulb, and then heated for 30 seconds on a hot plate heated to 125°C.Next, each photosensitive material was stacked on the image receiving material and exposed at 350 lux. kg/
For each positive color image (yellow color image) obtained on the image-receiving material through a CD pressure roller, the density (
Measurement (measurement wavelength: 440n)
m) did.

Further, for each of the yellow images obtained above, a photofading test was conducted as follows to evaluate the light resistance.

The photofading test was conducted by irradiating the obtained color image with xenon light of 80,000 lux for 3 hours, and then measuring the remaining density in the same manner as above. Note that the evaluation was expressed as the residual rate (%) of the color image after the previous color test.

The above measurement results are summarized in Table 2.

Table 2 As is clear from the results in Table 2, the light-sensitive materials (XxI) to (XI (XI) containing the color-forming side of the present invention are the same as the light-sensitive materials (XxI) and (XI) containing known leuco dyes. It exhibited a higher color density compared to the 100% polyurethane resin.Also, the color development rate was fast and it exhibited excellent light resistance.

Claims (1)

[Claims] 1. A recording material characterized by containing a leuco dye having a moiety represented by the following general formula [I]. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the above formula, R^1 and R^2 may be the same or different and represent a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group. Expression, also R^1 and R^2
may be linked through carbon atoms or heteroatoms to form a ring. R^3 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an aryl group, an alkoxy group, or an aryloxy group, R^4 represents a substituted or unsubstituted aryl group or a heterocyclic group, and R^
5 is a hydrogen atom, a halogen atom, an acetoxy group, a carbonyl group, a substituted carbamoyl group, a substituted sulfamoyl group, a sulfonylamino group, an acylamino group, an amino group, a hydroxy group, a nitro group, a cyano group, a substituted or unsubstituted alkyl group, a cyclo represents an alkyl group, aryl group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group or arylsulfonyl group, n represents a natural number from 1 to 5, and when n is 2 to 5, R^5 may be the same or different. Furthermore, a multimer may be formed by the moiety of general formula [I]. 2. The recording material according to claim 1, wherein the leuco dye is a compound having a moiety represented by the following general formula [II]. General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the above formula, R^1^1, R^1^2, R^1^3,
R^1^6 may be the same or different and represent a substituted or unsubstituted alkyl group, cycloalkyl group, or aryl group, and R^1^4 represents a substituted or unsubstituted aryl group or heterocyclic group; , R^1^5 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, or an aryl group, and l is 1 to 4.
represents a natural number, and when l is 2 to 4, R^1^5 may be the same or different. Also, R^1^1 and R^1
A multimer may be formed by the moiety of general formula [II] in which ^2 may be linked through carbon atoms or heteroatoms to form a ring.