JPH0859596A - Salicylic acid derivative, metal salt of the derivative, and thermosensitive recording material - Google Patents

Abstract

(57) [Summary] [Structure] A salicylic acid derivative represented by the general formula (1) and a metal salt of the derivative, (Wherein, X ₁ and X ₂ represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y represents an alkylene group, Z represents an oxygen atom or a sulfur atom) and electron donation A heat-sensitive recording material containing an electrochromic compound and an electron-accepting compound, wherein the electron-accepting compound contains at least one salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative. [Effect] The heat-sensitive recording material of the present invention is excellent in storage stability of an uncolored portion and a colored image.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a salicylic acid derivative useful as an electron-accepting compound for a recording material such as a pressure-sensitive or heat-sensitive recording material, or a monomer or an additive for a polymer material, and a metal salt of the salicylic acid derivative. And further relates to a heat-sensitive recording material having improved storage stability.

[0002]

2. Description of the Related Art Conventionally, recording materials (for example, pressure-sensitive recording materials, heat-sensitive recording materials, etc.) utilizing a color reaction between an electron-donating color-forming compound and an electron-accepting compound (developing agent) are well known. Has been. Organic acid compounds such as phenol compounds and carboxylic acid compounds are known to be useful as the electron-accepting compound, and many compounds have been proposed. For example, 2,2-bis (4′-hydroxyphenyl) propane [“bisphenol-A”] is widely used because it is inexpensive and easily available, but bisphenol A is used as an electron-accepting compound. The recording material has problems such as poor storage stability of uncolored portions and colored images. At present, there is a demand for a heat-sensitive recording material which has overcome these problems and is excellent in storage stability.

[0003]

An object of the present invention is to provide an electron-accepting compound for recording materials such as pressure-sensitive and heat-sensitive recording materials,
Another object is to provide a salicylic acid derivative and a metal salt of the derivative which are useful as a monomer or an additive for a polymer material. Furthermore, it is to provide a heat-sensitive recording material having excellent storage stability which overcomes the above-mentioned problems.

[0004]

The present inventors have accomplished the present invention as a result of extensive studies to meet the above-mentioned demand.
That is, the present invention is a salicylic acid derivative represented by the general formula (1) and a metal salt thereof.

[Chemical 3] (Wherein, X ₁ and X ₂ represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y represents an alkylene group, and Z represents an oxygen atom or a sulfur atom). Is a heat-sensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, and as the electron-accepting compound, at least one salicylic acid derivative represented by the general formula (1) or a metal salt of the acid derivative is used. The heat-sensitive recording material contained.

The salicylic acid derivative of the present invention is represented by the above general formula (1), and more specifically, in the general formula (1), X ₁ and X ₂ are a hydrogen atom, an alkyl group, an alkoxy group, Represents an aralkyl group, an aryl group or a halogen atom, preferably a hydrogen atom or a carbon number of 1 to 2
A chain alkyl group having 0, a cyclic alkyl group having 5 to 14 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a phenyl group, a fluorine atom, a chlorine atom or a bromine atom, and Preferably hydrogen atom, carbon number 1
~ 4 chain alkyl group, cyclohexyl group, carbon number 1 ~
4 is an alkoxy group, a benzyl group, an α-methylbenzyl group, a cumyl group or a phenyl group, and a hydrogen atom is particularly preferable.

In the general formula (1), Y represents an alkylene group and preferably has 1 to 2 total carbon atoms which may be branched.
0 is an alkylene group, more preferably an alkylene group having a total carbon number of 1 to 8 that may be branched, and further preferably an alkylene group having a total carbon number of 1 to 4 that may be branched, and particularly A trimethylene group is the preferred group.
In the general formula (1), Z represents an oxygen atom or a sulfur atom, and preferably an oxygen atom.

The salicylic acid derivative represented by the general formula (1) of the present invention has a carbamate group in the salicylic acid skeleton, and the substitution position of the carbamate group is 3-position, 4-position, 5-position in the salicylic acid skeleton. Or at the 6-position, preferably substituted at the 3-position, 4-position or 5-position, more preferably substituted at the 4-position or 5-position, particularly preferably substituted at the 4-position preferable.

That is, preferred specific examples of the salicylic acid derivative represented by the general formula (1) of the present invention include salicylic acid derivatives represented by the following general formulas (1-a) to (1-c). The salicyl derivative represented by the general formula (1-a) or (1-b) is more preferable, and the salicylic acid derivative represented by the general formula (1-a) is particularly preferable.

[Chemical 4]

[Chemical 5]

[Chemical 6] (In the formula, X ₁ , X ₂ , Y and Z are the same as above)

As the salicylic acid derivative represented by the general formula (1), for example, the following compounds can be exemplified, but of course the present invention is not limited thereto. No. Compound name 1) 3-carboxymethyloxycarbonylaminosalicylic acid 2) 3- (1′-carboxyethyloxycarbonylamino) salicylic acid 3) 3- (2′-carboxyethyloxycarbonylamino) salicylic acid 4) 3- (2 ′ -Carboxypropyloxycarbonylamino) salicylic acid 5) 3- (3'-carboxypropyloxycarbonylamino) salicylic acid 6) 3- (4'-carboxybutyloxycarbonylamino) salicylic acid 7) 3- (5'-carboxypentyloxycarbonyl Amino) salicylic acid 8) 3- (6'-carboxyhexyloxycarbonylamino) salicylic acid 9) 3- (7'-carboxyheptyloxycarbonylamino) salicylic acid 10) 3- (8'-carboxyoctyloxycarbonylamino) salicylic acid 1) 3- (11'-carboxydodecyloxycarbonylamino) salicylic acid 12) 3-carboxymethylthio-lcarbonylaminosalicylic acid 13) 3- (1'-carboxyethylthiolcarbonylamino) salicylic acid 14) 3- (2'-carboxy Ethylthiolcarbonylamino) salicylic acid 15) 5-Methyl-3- (3'-carboxypropyloxycarbonylaminosalicylic acid 16) 5-Cyclohexyl-3- (2'-carboxyethyloxycarbonylamino) salicylic acid 17) 5- Cumyl-3-carboxymethyloxycarbonylamino salicylic acid

18) 4-carboxymethyloxycarbonylaminosalicylic acid 19) 4- (1′-carboxyethyloxycarbonylamino) salicylic acid 20) 4- (2′-carboxyethyloxycarbonylamino) salicylic acid 21) 4- (2 ′ -Carboxypropyloxycarbonylamino) salicylic acid 22) 4- (3'-carboxypropyloxycarbonylamino) salicylic acid 23) 4- (4'-carboxybutyloxycarbonylamino) salicylic acid 24) 4- (5'-carboxypentyloxycarbonyl Amino) salicylic acid 25) 4- (6'-carboxyhexyloxycarbonylamino) salicylic acid 26) 4- (7'-carboxyheptyloxycarbonylamino) salicylic acid 27) 4- (8'-carboxyoctyloxy) Carbonylamino) salicylic acid 28) 4- (11-carboxydodecyloxycarbonylamino) salicylic acid 29) 3-ethyl-4- (3'-carboxypropyloxycarbonylamino) salicylic acid 30) 3-chloro-4- (1'-carboxy) Ethyloxycarbonylamino) salicylic acid 31) 4-Carboxymethylthiolcarbonylaminosalicylic acid 32) 4- (1'-carboxyethylthiolcarbonylamino) salicylic acid

33) 5-Carboxymethyloxycarbonylaminosalicylic acid 34) 5- (1′-carboxyethyloxycarbonylamino) salicylic acid 35) 5- (2′-carboxyethyloxycarbonylamino) salicylic acid 36) 5- (3 ′ -Carboxypropyloxycarbonylamino) salicylic acid 37) 5- (4'-carboxybutyloxycarbonylamino) salicylic acid 38) 5- (5'-carboxypentyloxycarbonylamino) salicylic acid 39) 5- (6'-carboxyhexyloxy Carbonylamino) salicylic acid 40) 5- (7′-carboxyheptyloxycarbonylamino) salicylic acid 41) 5- (8′-carboxyoctyloxycarbonylamino) salicylic acid 42) 5- (11-carboxydodecyl Oxycarbonylamino) salicylic acid 43) 3-Methyl-5- (2'-carboxyethyloxyamino) salicylic acid 44) 3-Ethoxy-5- (3'-carboxypropyloxycarbonylamino) salicylic acid 45) 3-phenyl-5- (2'-Carboxyethyloxycarbonylamino) salicylic acid

46) 6-Carboxymethyloxycarbonylaminosalicylic acid 47) 6- (3′-carboxypropyloxycarbonylamino) salicylic acid 48) 6- (4′-carboxybutyloxycarbonylamino) salicylic acid 49) 6- (5 ′ -Carboxypentyloxycarbonylamino) salicylic acid 50) 6- (7'-carboxyheptyloxycarbonylamino) salicylic acid 51) 3-ethyl-6- (2'-carboxyethyloxycarbonylamino) salicylic acid 52) 3-tert- Butyl-6- (1'-carboxyethyloxycarbonyl amino) salicylic acid

The salicylic acid derivative represented by the general formula (1) of the present invention is
It is preferably produced by reacting a carboxylic acid derivative represented by the general formula (3) or an alkali metal salt thereof.

[Chemical 7] (In the formula, R ₁ represents an aryl group, and X ₁ and X ₂ are the same as above) HZY-COOH (3) (In the formula, Y and Z are the same as above)

In the compound represented by the general formula (2),
R ₁ represents an aryl group, preferably an aryl group having 6 to 20 carbon atoms which may have a substituent, and more preferably an aryl group having 6 to 12 carbon atoms which may have a substituent. And a phenyl group which may have a substituent is particularly preferable. The compound represented by the general formula (2) is a known compound, and is suitably produced by a method known per se, typically a method of reacting an aminosalicylic acid derivative with chloroformic acid aryl ester.

The carboxylic acid derivative represented by the general formula (3) or its alkali metal salt, which is the other starting material for producing the salicylic acid derivative represented by the general formula (1), is a known compound. It is preferably produced by a method known per se.

Examples of the compound represented by the general formula (3) include hydroxyacetic acid, 2-hydroxypropanoic acid, and 3
-Hydroxypropanoic acid, 2-hydroxybutanoic acid, 3
-Hydroxybutanoic acid, 4-hydroxybutanoic acid, 2-
Hydroxypentanoic acid, 3-hydroxypentanoic acid, 4
-Hydroxypentanoic acid, 2-hydroxyhexanoic acid,
3-hydroxyhexanoic acid, 4-hydroxyhexanoic acid, 5-hydroxyhexanoic acid, 6-hydroxyhexanoic acid, 2-hydroxyheptanoic acid, 3-hydroxyheptanoic acid, 4-hydroxyheptanoic acid, 5-hydroxyheptanoic acid, 6- Hydroxyheptanoic acid, 7-hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 3-hydroxyoctanoic acid, 4-hydroxyoctanoic acid, 5-hydroxyoctanoic acid, 6-hydroxyoctanoic acid, 7-hydroxyoctanoic acid, 8-hydroxyoctane Acid, 2-hydroxynonanoic acid, 3-hydroxynonanoic acid, 4-hydroxynonanoic acid, 5-hydroxynonanoic acid, 6-hydroxynonanoic acid, 7-hydroxynonanoic acid, 8-hydroxynonanoic acid, 2-hydroxydecanoic acid, 3-hydroxydecanoic acid, 4-hydr Xydecanoic acid, 5-hydroxydecanoic acid, 6-hydroxydecanoic acid, 7-hydroxydecanoic acid, 8-hydroxydecanoic acid, 9-hydroxydecanoic acid, 10-hydroxydecanoic acid, 2-hydroxypaltimic acid, 16-hydroxypaltimic acid Specific examples of such compounds include 12-hydroxystearic acid, mercaptoacetic acid, 2-mercaptopropanoic acid, and 3-mercaptopropanoic acid.

A solvent may be used when the salicylic acid derivative represented by the general formula (1) is produced by the above method. The solvent is not particularly limited, and examples thereof include hydrocarbon solvents such as benzene, toluene, xylene, pentane, hexane, heptane, octane and cyclohexane, diethyl ether, tetrahydrofuran, 1,4-dioxane, diethylene glycol dimethyl ether. Ether solvent such as ethyl acetate, acetic acid n
-Ethyl solvent such as butyl and amyl acetate, halogen solvent such as dichloromethane, chloroform, dichloroethane, chlorobenzene and dichlorobenzene, acetone,
An organic solvent such as an aprotic polar solvent such as methyl ethyl ketone, acetonitrile, dimethyl sulfoxide, N, N-dimethylformamide, N-methylpyrrolidone, N, N-dimethylimidazolidinone or an aqueous solvent can be mentioned. The above solvents may be used alone or in combination.

The amount of the solvent to be used is not particularly limited, but it is obvious that using too much is not preferable from the viewpoint of production efficiency, and using an excessively small amount results in long production. It takes time, which is not preferable in terms of manufacturing efficiency. Usually, the solvent is preferably used in an amount of 0.5 to 200 times, more preferably 0.5 to 100 times, the weight of the compound represented by the general formula (2).

The amount of the compound represented by the general formula (3) used is not particularly limited, but is usually 0.9 to 2 with respect to 1 mol of the compound represented by the general formula (2). ．
It is about 0 mol, and more preferably about 1 to 1.2 mol. The reaction temperature is not particularly limited,
Generally, it is preferably carried out in the range of -20 ° C to the boiling point of the solvent, more preferably 0 ° C to the boiling point of the solvent. Although the reaction time varies depending on the reaction temperature, it usually requires several minutes to several hours. Since the progress of the reaction can be monitored by a known analytical means (for example, high performance liquid chromatography), the end point of the reaction can be determined.

A base may be used when the salicylic acid derivative represented by the general formula (1) is produced by the above method.
The base is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate,
Examples thereof include inorganic bases such as potassium hydrogen carbonate, sodium carbonate and potassium carbonate, and organic bases such as triethylamine, dimethylaniline, diethylaniline and pyridine. These bases may be used alone or in combination. The amount of the base used is not particularly limited, but it is usually the compound 1 represented by the general formula (2).
It is preferable to use about 0.01 to 10 mol, and more preferably about 0.1 to 5 mol, based on mol. After completion of the reaction, the reaction product can be obtained by carrying out usual post-treatment operations (for example, filtration, drying, neutralization, solvent removal, etc.), and further known purification methods (for example, recrystallization,
The purity can be further increased by column chromatography). The salicylic acid derivative represented by the general formula (1) of the present invention can be produced by the above method.

This salicylic acid derivative of the present invention has a structure having two carboxyl groups in the same molecule. Therefore, the metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention is either There are compounds in which only a carboxyl group is metal-chlorided, and compounds in which two carboxyl groups are both metal-chlorided, and both of them are included. That is, in the metal salt of the salicylic acid derivative represented by the general formula (1), a compound in which only one carboxyl group is metal chloride (hereinafter, referred to as metal salt / mono body) and two carboxyl groups are both There is a valent metal salt compound (hereinafter referred to as a metal salt / di-form), and the metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention is the metal salt / mono-form or metal salt described above.・
It includes both di bodies.

The metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention includes monovalent metal salts such as sodium, potassium and lithium, and divalent, trivalent and tetravalent metal salts (polyvalent). (Valent metal salt). Specific examples of the polyvalent metal salt include salts of zinc, magnesium, calcium, barium, nickel, tin, copper, manganese, cobalt, titanium, aluminum, iron and the like, preferably zinc, magnesium, calcium. , Barium, nickel, manganese, cobalt, and aluminum salts, more preferably zinc, calcium, and manganese salts, and zinc salts are particularly preferable.

The alkali metal salt of the salicylic acid derivative represented by the general formula (1) is usually 0.8 to 2.4 mol, relative to 1 mol of the salicylic acid derivative represented by the general formula (1).
Preferably, 1.0 to 2.2 mol of an alkali metal compound (eg, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, etc.) is allowed to act in the presence of water. Can be manufactured by.

The polyvalent metal salt of salicylic acid derivative represented by the general formula (1) is an alkali metal salt (eg, metal salt of sodium, potassium, lithium, etc.), amine salt, ammonium salt, etc. of the salicylic acid derivative. It is produced as a polyvalent metal salt of a sparingly water-soluble or water-insoluble salicylic acid derivative by a metathesis method from an aqueous solution of a water-soluble salt thereof and an aqueous solution of a corresponding water-soluble polyvalent metal compound.
At this time, heating may be performed or an organic solvent may coexist as desired. The water-soluble salt such as the alkali metal salt, amine salt, or ammonium salt of the salicylic acid derivative represented by the general formula (1) is usually prepared by mixing 1 mol of the salicylic acid derivative represented by the general formula (1) with 0.8 ~
2.4 mol, preferably 1.0 to 2.2 mol of an alkali metal compound (for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, etc.) or an amine compound ( For example, methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, ethanolamine, isopropanolamine, triethanolamine, 2-dimethylethanolamine,
Morpholine, ammonia, etc.) in the presence of water.

In producing the metal salt of the salicylic acid derivative represented by the general formula (1), in addition to water, a water-soluble organic solvent such as an alcohol solvent such as methanol, isopropanol, methyl cellosolve or ethylene glycol,
Ether solvents such as tetrahydrofuran and dioxane,
A ketone-based solvent such as acetone and an aprotic polar solvent such as N, N-dimethylformamide, N-methyl-2-pyrrolidone, dimethylsulfoxide and sulfolane may be allowed to coexist.

Examples of the water-soluble polyvalent metal compounds include sulfates such as zinc sulfate, magnesium sulfate, calcium sulfate and aluminum sulfate, zinc chloride, magnesium chloride, calcium chloride, barium chloride, nickel chloride and cobalt chloride. , Chlorides such as aluminum chloride, and acetates such as zinc acetate and manganese acetate. The amount of these water-soluble polyvalent metal compounds used is based on the water-soluble salts such as the alkali metal salt, amine salt, and ammonium salt of the salicylic acid derivative represented by the general formula (1) obtained by the above method. , For example, 0.5 to 4.0 equivalents, preferably 1.0 to 2.4 equivalents.

As described above, the salicylic acid derivative represented by the general formula (1) of the present invention has a structure having two carboxyl groups in the same molecule. For example, one carboxyl group is alkali metal salified. (Hereinafter, referred to as an alkali metal salt / mono body) and a compound in which two carboxyl groups are both alkali metal salified (hereinafter, referred to as an alkali metal salt / di body). In this case, for example, the alkali metal salt of the salicylic acid derivative represented by the general formula (1) includes the above-mentioned alkali metal salt / mono body and alkali metal salt / di body,
With respect to 1 mol of the alkali metal salt of the salicylic acid derivative,
0.5 mol of a divalent zinc compound (for example, zinc sulfate) corresponds to 1 equivalent.

The temperature for producing the metal salt of the salicylic acid derivative represented by the general formula (1) is not particularly limited, but is preferably about 0 ° C to about 50 ° C, more preferably about 10 ° C. C to about 40 ° C. After the metathesis, the metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention can be obtained by a known method (for example, filtration, drying, etc.). The metal salt of the salicylic acid derivative represented by the general formula (1) produced as described above is sometimes a solvate such as a hydrate depending on the type of the salicylic acid derivative represented by the general formula (1), production conditions and the like. The metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention is also included in the solvate of the metal salt.

When the alkali and / or polyvalent metal salt of the salicylic acid derivative represented by the general formula (1) of the present invention is used as the electron-accepting compound of the heat-sensitive recording material, it is preferably water-insoluble or water-insoluble. It is a valent metal salt, more preferably a divalent metal salt.

The heat-sensitive recording material of the present invention is a heat-sensitive recording material containing an electron-donating color forming compound and an electron-accepting compound, wherein the electron-accepting compound is a salicylic acid derivative represented by the general formula (1) or a derivative thereof. At least one metal salt of In addition, the effect of the salicylic acid derivative of the present invention or the metal salt of the derivative as an electron-accepting compound is that the inclusion of the metal compound enhances the storage stability of the color image in the thermosensitive recording material.

The metal compound may be divalent, trivalent or tetravalent.
Valent metals, for example, oxides of metals selected from zinc, magnesium, barium, calcium, aluminum, tin, titanium, nickel, cobalt, manganese, iron and the like,
Hydroxide, sulfide, halide, carbonate, phosphate,
Examples thereof include silicates, sulfates and nitrates.
In particular, zinc compounds are preferable. Specific examples of the metal compound include, for example, zinc oxide, zinc hydroxide, zinc aluminate, zinc sulfide, zinc carbonate, zinc phosphate, zinc silicate, zinc thiocyanate, magnesium sulfate, magnesium aluminate, magnesium hydroxide, and oxide. Examples thereof include magnesium, magnesium carbonate, barium carbonate, calcium sulfate, calcium chloride, calcium carbonate, aluminum oxide, aluminum hydroxide, aluminum silicate, aluminum phosphate, tin oxide and titanium oxide. These metal compounds may be used alone or in combination. Particularly preferred are zinc carbonate and zinc oxide. The amount of these metal compounds used is not particularly limited, but is usually 100 parts by weight of the salicylic acid derivative represented by the general formula (1) used as the electron-accepting compound or the metal salt of the derivative. It is desirable to use 1 to 500 parts by weight, preferably 3 to 300 parts by weight.

The method of incorporating the metal compound into the heat-sensitive recording material of the present invention is not particularly limited. For example, a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative is used. And a metal compound are mixed in advance to obtain a dispersion liquid, or a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative and a metal compound are separately dispersed. A method of applying the dispersion obtained by mixing the dispersions of 1. to the support is applied.

A mixture of a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative as an electron-accepting compound used in the heat-sensitive recording material of the present invention and a metal compound and / or a heat-fusible compound is prepared. At this time, it is not necessary to stir and mix, but it is preferable to stir and mix using an appropriate stirring and mixing device. As the stirring and mixing device, for example, a mortar, a propeller-type stirrer, a turbine-type stirrer, a paddle-type stirrer, a homogenizer, a homomixer, a line mixer, a line homomixer, and the like without using a medium, a mixing device, or an attritor, Media such as stirring tank type mills such as Sentry mills, sand grinders, crane mills, pearl mills, matter mills, flow tube type mills such as Dyno mills, conical ball mills, annular type continuous wet stirring mills such as annular mills (for example, glass beads, ceramics Examples include a stirring and mixing device filled with balls, steel balls and the like. Usually, the mixture can be prepared under atmospheric pressure, but may be prepared under reduced pressure or under pressure, if desired. Furthermore, if desired, the mixture can be prepared under an inert gas atmosphere such as nitrogen gas, argon gas, or helium gas.

Examples of the colorless or light-colored electron-donating color-forming compound used in the present invention include triarylmethane compounds, diarylmethane compounds, rhodamine-lactam compounds, fluorane compounds, indolylphthalide compounds, divinyl. Examples thereof include various known electron-donating color-forming compounds such as phthalide compounds, pyridine compounds, spiro compounds, fluorene compounds and thiazine compounds.

Among the above-mentioned electron-donating color-forming compounds,
A fluoran compound is preferable, and a fluoran compound represented by the general formula (a) is more preferable.

Embedded image (In the formula, A and B are an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkoxyalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a tetrahydrofurfuryl group. Further, A and B may be bonded to form a pyrrolidine ring, a piperidine ring or a morpholine ring, and X is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or Represents a halogen atom, Y and Z are hydrogen atom, halogen atom, carbon number 1
Represents an alkyl group or a trifluoromethyl group of 4)

To give some specific examples of the electron-donating color-forming compound, the triarylmethane compounds are:
For example, 3,3-bis (4-dimethylaminophenyl)
-6-Dimethylaminophthalide ["Crystal Violet Lactone"], 3,3-bis (4-dimethylaminophenyl) phthalide, 3- (4-dimethylaminophenyl) -3- (4-diethylaminophenyl) -6- Dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -6-dimethylaminophthalide, 3
Examples include-(4-dimethylaminophenyl) -3- (1-methylpyrrol-3-yl) -6-dimethylaminophthalide.

Examples of the diarylmethane compounds include 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leuco auramine,
N-2,4,5-trichlorophenyl leuco auramine and the like.

As the rhodamine-lactam compound,
For example, rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino) lactam, rhodamine-B
-(2-chloroanilino) lactam and the like.

Examples of fluoran compounds include:
3,6-dimethoxyfluorane, 3-diethylamino-
6-methoxyfluorane, 3-dimethylamino-7-methoxyfluorane, 3-diethylamino-7-methylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-N- Ethyl-N-isopentylamino-7-methylfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-
Methyl-7-chlorofluorane, 3-diethylamino-
6,7-Dimethylfluorane, 3,6-bis (diphenylamino) fluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-di-n-butylamino-
7-dibenzylaminofluorane, 3-diethylamino-7-di-n-hexylaminofluorane, 3-diethylamino-7-n-octylaminofluorane, 3-diethylamino-7-anilinofluorane, 3-N -Ethyl-N-isopentylamino-7-anilinofluorane, 3-diethylamino-7- (2'-chlorophenylamino) fluorane, 3-diethylamino-7- (3 '
-Chlorophenylamino) fluorane, 3-diethylamino-7- (2 ', 3'-dichlorophenylamino) fluorane, 3-diethylamino-7- (3'-trifluoromethylphenylamino) fluorane, 3-di-n-
Butylamino-7- (2'-chlorophenylamino) fluorane, 3-diethylamino-7- (2'-fluorophenylamino) fluorane, 3-di-n-butylamino-7- (2'-fluorophenylamino) fluorane , 3-diethylamino-6-chloro-7-anilinofluorane, 3-di-n-butylamino-6-chloro-7
-Anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy-7-anilinofluorane,

3-Pyrrolidino-6-methyl-7-anilinofluorane, 3-morpholino-6-methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7
-Anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3-di-n
-Pentylamino-6-methyl-7-anilinofluorane, 3-di-n-octylamino-6-methyl-7-anilinofluorane, 3-N-n-propyl-N-methylamino-6- Methyl-7-anilinofluorane, 3-N
-N-butyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-n-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-
Isobutyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-Nn
-Pentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-
n-hexyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-n-octyl-N-ethylamino-6-methyl-7-anilinofluorane,

3-N-cyclopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N -Cyclohexyl-N-n-
Propylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-butylamino-
6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-hexylamino-6-methyl-7-
Anilinofluorane, 3-N-cyclohexyl-Nn
-Octylamino-6-methyl-7-anilinofluorane, 3-N- (2'-methoxyethyl) -N-isobutylamino-6-methyl-7-anilinofluorane, 3-
N- (2'-ethoxyethyl) -N-ethylamino-6
-Methyl-7-anilinofluorane, 3-N- (3'-
Methoxypropyl) -N-methylamino-6-methyl-
7-anilinofluorane, 3-N- (3'-methoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl)-
N-methylamino-6-methyl-7-anilinofluorane, 3-N- (3'-ethoxypropyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N
-(2'-Tetrahydrofurfuryl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-N-
(4′-methylphenyl) -N-ethylamino-6-methyl-7-anilinofluorane,

3-Diethylamino-6-ethyl-7-anilinofluorane, 3-diethylamino-6-methyl-
7- (3'-methylphenylamino) fluorane, 3-
Diethylamino-6-methyl-7- (2 ', 6'-dimethylphenylamino) fluorane, 3-di-n-butylamino-6-methyl-7- (2', 6'-dimethylphenylamino) fluorane, 3 -Di-n-butylamino-
7- (2 ', 6'-dimethylphenylamino) fluorane, 2,2-bis [4'-(3-N-cyclohexyl-
N-methylamino-6-methylfluorane) -7-ylaminophenyl] propane, 3- [4 ′-(4-phenylaminophenyl) aminophenyl] amino-6-methyl-7-chlorofluorane, etc. .

Examples of indolyl phthalide compounds include 3,3-bis (1,2-dimethylindole-3)
-Yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) ) -6-Dimethylaminophthalide,
3,3-bis (1-ethyl-2-methylindole-3
-Yl) phthalide, 3,3-bis (1-octyl-2-
Methylindol-3-yl) phthalide, 3- (4-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl) phthalide, 3- (4-dimethylaminophenyl) -3- (2- Methylindol-3-yl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, 3- (2-ethoxy-4-dibutyl) Aminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) ) There are phthalides.

Examples of the divinylphthalide compound include 3,3-bis [2,2-bis (4-dimethylaminophenyl) ethenyl] -4,5,6,7-tetrachlorophthalide and 3,3. -Bis [2,2-bis (4-pyrrolidinophenyl) ethenyl] -4,5,6,7-tetrabromophthalide, 3,3-bis [2- (4-methoxyphenyl) -2- (4 -Dimethylaminophenyl) ethenyl]
-4,5,6,7-Tetrachlorophthalide, 3,3-bis [2- (4-methoxyphenyl) -2- (4-pyrrolidinophenyl) ethenyl] -4,5,6,7-tetra Chlorophthalide etc.

Examples of the pyridine compound include 3-
(2-Ethoxy-4-diethylaminophenyl) -3-
(1-Ethyl-2-methylindol-3-yl) -4
Or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-) Diethylaminophenyl) -3- (1-octyl-2-methylindole-3
-Yl) -4 or 7-azaphthalide, 3- (2-hexyloxy-4-diethylaminophenyl) -3- (1
-Ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-n-butoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide, 3- (4-diethylamino-2-methylphenyl)
-3- (1-Ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (4-diethylamino-2-methylphenyl) -3- (1-n-octyl-2-methylindole -3-yl) -4 or 7-
Azaphthalide, 3,3-bis (4-diethylamino-2)
-Methoxyphenyl) -4 or 7-azaphthalide,
Examples include 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4 or 7-azaphthalide.

Examples of spiro compounds include 3-methyl-spiro-dinaphthopyran and 3-ethyl-spiro-
Dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxybenzo) spiropyran, 3
-Propyl-spiro-dibenzopyran and the like.

Examples of the fluorene compound include:
3,6-bis (dimethylamino) fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3-diethylamino-6- (N-allyl-N-methylamino)
Fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3,6-bis (dimethylamino) -spiro [fluorene-9,6'-6'H-chromeno (4,3
-B) indole], 3,6-bis (dimethylamino)
-3'-methyl-spiro [fluorene-9,6'-6 '
H-chromeno (4,3-b) indole], 3,6-bis (diethylamino) -3'-methyl-spiro [fluorene-9,6'-6'H-chromeno (4,3-b) indole] and so on.

Examples of thiazine compounds include benzoyl leuco methylene blue and 4-nitrobenzoyl leuco methylene blue. These electron-donating color forming compounds may be used alone or in combination.

As the electron-donating color forming compound, in particular,
Fluoran compounds that develop black color are preferable, and among them,
Preferably, di-n-butylamino-7- (2'-chlorophenylamino) fluorane, 3-dimethylamino-
6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-
n-Butylamino-6-methyl-7-anilinofluorane, 3-di-n-pentylamino-6-methyl-7-anilinofluorane, 3-N-n-propyl-N-methylamino-6 -Methyl-7-anilinofluorane, 3-N
-N-butyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-
Isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-
(2'-Methoxyethyl) -N-isobutylamino-6
-Methyl-7-anilinofluorane, 3-N- (3'-
Ethoxypropyl) -N-ethylamino-6-methyl-
7-anilinofluorane and 3-diethylamino-6-methyl-7- (3′-methylphenylamino) fluorane.

In the heat-sensitive recording material of the present invention, the proportions of the electron-donating color-forming compound and the electron-accepting compound used are not particularly limited, but usually 100 parts by weight of the electron-donating color-forming compound are used. Electron-accepting compound 50
It is desirable to use ˜700 parts by weight, preferably 100 to 500 parts by weight.

The heat-sensitive recording material of the present invention contains at least one salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative as an electron-accepting compound. It is also possible to use other electron-accepting compounds in combination as long as the effect is not impaired. In this case, the proportion of the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative in the total electron-accepting compound is usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more. It is desirable to adjust the content to be not less than weight%.

The electron-accepting compound other than the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative is an organic electron-accepting compound such as a phenol derivative, an organic acid or a metal salt or complex thereof, a urea derivative, or the like. Inorganic electron-accepting compounds such as acid clay are mentioned. Some specific examples of these compounds are, for example, 4
-Tert-butylphenol, 4-tert-octylphenol, 4-phenylphenol, 1-naphthol, 2-
Naphthol, hydroquinone, resorcinol, 4-te
rt-octylcatechol, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether,
2,2-bis (4'-hydroxyphenyl) propane ["bisphenol A"], 1,1-bis (4'-hydroxyphenyl) cyclohexane, 2,2-bis (4 ')
-Hydroxy-3'-methylphenyl) propane, 1,
3-bis (4'-hydroxycumyl) benzene, 1,4
-Bis (4'-hydroxycumyl) benzene, 1,3
5-tris (4'-hydroxycumyl) benzene, 2,
2-bis (4'-hydroxyphenyl) acetic acid ethyl ester, 4,4- (4'-hydroxyphenyl) pentanoic acid-n-butyl ester, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid phenethyl ester, 2 , 4-dihydroxybenzoic acid phenoxyethyl ester, 4-hydroxyphthalic acid dimethyl ester,
Gallic acid-n-propyl ester, gallic acid-n-octyl ester, gallic acid-n-dodecyl ester, gallic acid-n-octadecyl ester, hydroquinone monobenzyl ether, bis (3-methyl-4-hydroxyphenyl) sulfide, Bis (2-methyl-4-hydroxyphenyl) sulfide, bis (3-phenyl-4-)
Hydroxyphenyl) sulfide, bis (3-cyclohexyl-4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide,

Bis (4-hydroxyphenyl) sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-tert-butyldiphenyl sulfone, 4 -Hydroxy-4'-chlorodiphenyl sulfone, 4-hydroxy-4'-methoxydiphenyl sulfone, 4-hydroxy-4'-n-propoxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-
4'-n-butoxydiphenyl sulfone, 4-hydroxy-4'-benzyloxydiphenyl sulfone,
3,4-dihydroxy-4'-methyldiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone,
2-methoxy-4'-hydroxydiphenyl sulfone, 2-ethoxy-2'-hydroxydiphenyl sulfone, 4-hydroxy-3-methyl-4'-n-propoxydiphenyl sulfone, bis (2-hydroxy-5)
-Tert-butylphenyl) sulfone, bis (2-hydroxy-5-chlorophenyl) sulfone, bis [4-
(3'-Hydroxyphenyloxy) phenyl] sulfone, 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 1,7-bis (4'-hydroxyphenylthio) -3,5-dioxaheptane, 1,5
-Phenol derivatives such as bis (4'-hydroxyphenylthio) -3-oxapentane, or metal salts of these phenol derivatives (for example, metal salts such as nickel, zinc, aluminum, magnesium, calcium and titanium);

For example, salicylic acid, 3-isopropylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 3-methyl-5-α-methylbenzyl. Salicylic acid, 4- [2 '-(4-methoxyphenyloxy) ethyloxy] salicylic acid, 4- [3'-(4-
Methylphenylsulfonyl) propyloxy] salicylic acid, 4- [3 ′-(4-methoxyphenylsulfonyl)
Propyloxy] salicylic acid, 5- {4 '-[2- (4
-Methoxyphenyloxy) ethyloxy] cumyl} salicylic acid, 1-naphthoic acid, 2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-6-naphthoic acid, 6-acetoxy-2-naphthoic acid, phthalic acid Monobenzyl ester, phthalic acid monophenyl ester, isophthalic acid, 4-methylbenzoic acid, 2-benzoylbenzoic acid, 2- (4'-chlorobenzoyl) benzoic acid, 4-
Organic acids such as nitrobenzoic acid, 4-chlorobenzoic acid and 4-formylbenzoic acid or metal salts thereof (for example, metal salts such as nickel, zinc, aluminum, magnesium, calcium and titanium),

For example, complexes such as zinc thiocyanate antipyrine complex and molybdic acid acetylacetone complex, for example, N, N'-diphenylthiourea, N, N'-di (3-trifluoromethylphenyl) thiourea, 1,4
-Di (3'-chlorophenyl) -3-thiosemicarbazide, N-phenyl-N '-(4-methylphenylsulfonyl) urea, urea such as 4,4'-bis (4 "-methylphenylsulfonylcarbonylamino) diphenylmethane Organic electron-accepting compounds such as derivatives,

Examples thereof include inorganic electron-accepting compounds such as acid clay, attapulgite, colloidal silica, aluminum silicate, activated clay, aluminum chloride, zinc chloride and zinc bromide, but are not limited thereto. . These electron-accepting compounds can be used in combination. Among these, phenol derivatives are particularly preferable electron-accepting compounds.

The heat-sensitive recording material of the present invention is further provided with various known formulations (addition of a heat-fusible compound) for producing a known heat-sensitive recording material, as described below.
In the heat-sensitive recording material of the present invention, if desired, a heat-fusible compound (a compound having a melting point of about 70 to 150 ° C., more preferably a melting point of about 80 to 130 ° C.) may be further added to the heat-sensitive recording material of the present invention. This is preferable in order to obtain a heat-sensitive recording material compatible with high speed recording. In this case, the amount of the heat-fusible compound used is not particularly limited, but is usually 10 to 700 parts by weight of the heat-fusible compound, preferably 100 parts by weight of the electron-donating color forming compound,
It is desirable to use 20 to 500 parts by weight.

Specific examples of the heat-fusible compound include caproic acid amide, capric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, linoleic acid amide, linolenic acid amide, and the like. N-ethylcapric acid amide, N-butyllauric acid amide, N-methylstearic acid amide, N-methyloleic acid amide, N-stearylcyclohexylamide, N-octadecylacetamide, N-oleinacetamide, stearylurea, stearic acid anilide , Benzanilide, linoleic acid anilide, acetoacetic acid anilide, o-acetoacetic acid toluidide, p-acetoacetic acid anisidide, N-ethylcarbazole, 4-methoxydiphenylamine, N-hydroxymethylstearic acid amide,
Nitrogen-containing compounds such as ethylenebisstearic acid amide,

For example, 4-benzyloxybenzoic acid benzyl ester, 2-naphthoic acid phenyl ester, 1-
Hydroxy-2-naphthoic acid phenyl ester, oxalic acid dibenzyl ester, oxalic acid di (4-methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester, adipic acid diphenyl ester, glutaric acid diphenacyl ester, diester (4-methylphenyl) carbonate, terephthalic acid dimethyl ester, terephthalic acid di-n-butyl ester, terephthalic acid dibenzyl ester, isophthalic acid di-n-butyl ester, isophthalic acid bis (4-benzyloxycarbonylphenyl) ester, An ester compound such as bis [2- (benzoyloxy) ethyl] sulfide,

Hydrocarbon compounds such as 4-benzylbiphenyl, m-terphenyl, fluorene, fluoranthene, 2,6-diisopropylnaphthalene and 3-benzylacenaphthene,

For example, 2-benzyloxynaphthalene,
2- (4'-methylbenzyloxy) naphthalene, 1,
4-diethoxynaphthalene, 1,2-diphenoxyethane, 1,2-bis (3′-methylphenoxy) ethane,
1,2-bis (4'-methylphenoxy) ethane, 1-
Phenoxy-2- (4'-ethylphenoxy) ethane,
1- (4'-methoxyphenoxy) -2-phenoxyethane, 1- (4'-methoxyphenoxy) -2- (3 '
-Methylphenoxy) ethane, 1- (4'-methoxyphenoxy) -2- (2'-methylphenoxy) ethane,
1- (4'-methoxyphenoxy) -2-phenoxypropane, 1-phenoxy-2- (4'-methoxyphenoxy) propane, 1,2-bis (4'-methoxyphenoxy) propane, 1,3-bis ( 4'-methoxyphenoxy) propane, 1- (4'-methoxyphenoxy)-
2- (2'-chlorophenoxy) ethane, 1,4-diphenoxybutane, bis [2- (4'-methoxyphenoxy) ethyl] ether, 4- (4'-methylphenoxy) biphenyl, 1,2-di Phenoxybenzene, 1,
4-diphenoxybenzene, 1,4-bisbenzyloxybenzene, 1,4-bis (2'-chlorobenzyloxy) benzene, 1,4-bis (2'-chlorophenoxy) benzene, 1,4-bis ( 4'-methylphenoxy) benzene, 1,4-bis (3'-methylphenoxymethyl) benzene, 4- (4'-chlorobenzyloxy) ethoxybenzene, 4,4'-bis (phenoxy)
Diphenyl ether, 1,4-bis (4'-benzylphenoxy) benzene, 1,4-bis [(4'-methylphenyloxy) methoxymethyl] benzene, 4- (4 '
-Methoxybenzylthio) anisole, 1-phenoxy-2- (4'-methoxyphenylthio) ethane, 1,2
-Bis (4'-methoxyphenylthio) ethane, 1-
(4'-methylphenoxy) -2- (4'-methoxyphenylthio) ethane, benzyl-4-methylthiophenyl ether, 4,4'-bis (phenoxy) diphenylthioether, 4,4'-di-n-butoxy Ether compounds such as diphenyl sulfone or sulfur-containing compounds,

For example, 1,4-di (glycidyloxy)
Benzene, 1,4-diglycidyl terephthalate, 4-
Glycidyloxy-4'-isopropyloxydiphenyl sulfone, 4-[(2,3-epoxy-2-methyl) propyloxy] phenyl-4 '-(benzyloxy) phenyl sulfone, 4-[(2,3-epoxy)
A compound having an epoxy group such as propyloxy] phenyl-4 ′-(4-methylbenzyloxy) diphenylsulfone,

For example, 2- (2'-hydroxy-5'-
Methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole, 2
-(2'-hydroxy-3'-tert-butyl-5 '
-Methylphenyl) -5-chlorobenzotriazole,
2- (2'-hydroxy-3 ', 5'-di-tert-
Butylphenyl) -5-chlorobenzotriazole, 2
Examples thereof include triazole compounds such as-(2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole and 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole. However, the invention is not limited to these. These heat-fusible compounds may be used alone or in combination.

The heat-sensitive recording material of the present invention can be manufactured by a known method without using a special method. Generally, in the presence of water, an electron-donating color-forming compound, a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative, and, if desired, a heat-fusible compound, a metal compound, etc. , Together or separately in a water-soluble binder, using a ball mill, sand mill, sand mill (vertical type, horizontal type), attritor, colloidal mill or the like, by a pulverizer, usually 3 μm or less, preferably 2 μm or less.
The coating liquid for the heat-sensitive recording layer can be prepared by pulverizing and dispersing to a particle size of μm or less and mixing. In such coating liquid,
The binder is blended in an amount of about 5 to 50% by weight of the total solid content.

As the binder, a water-soluble binder is generally used, for example, polyvinyl alcohol,
Carboxy modified polyvinyl alcohol, sulfonation modified polyvinyl alcohol, polyvinyl alcohol derivatives such as alkyl modified polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, cellulose derivatives such as hydroxypropyl cellulose, epichlorohydrin modified polyamide, ethylene-maleic anhydride copolymer, Styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyacrylic acid, polyacrylamide, methylol-modified polyacrylamide, starch, starch derivative (oxidized starch, etherified starch, etc.), casein,
Examples thereof include gelatin and gum arabic,
It is not limited to these.

Further, in the recording layer of the heat-sensitive recording material of the present invention, if necessary, a pigment, a water-insoluble binder, a metal soap, a wax, a surfactant, an ultraviolet absorber, an ultraviolet stabilizer, a crosslinking agent, and a hindered agent. Add phenol, antifoaming agent, etc. Examples of the pigment include calcium carbonate, barium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, aluminum oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, talc, wax stone, kaolin, clay, diatomaceous earth, Inorganic pigments such as silica, organic pigments such as styrene microballs, nylon particles, urea-formalin fillers, polyethylene particles, cellulose fillers and starch particles are used.

As the water-insoluble binder, synthetic rubber latex or synthetic resin emulsion is generally used,
For example, styrene-butadiene rubber latex, acrylonitrile-butadiene latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion and the like are known, and they are used as necessary. Examples of the metal soaps include higher fatty acid metal salts such as zinc stearate, calcium stearate, aluminum stearate and zinc oleate.

Examples of the wax include paraffin wax, microcrystalline wax, carboxy-modified paraffin wax, carnauba wax, polyethylene wax, polystyrene wax, candelia wax, montan wax and higher fatty acid ester.

As the surfactant (dispersant), for example,
Sulfosuccinic acid-based alkali metal salts [for example, di (n-
Hexyl) sulfosuccinic acid, di (2-ethylhexyl)
Sodium salt of sulfosuccinic acid, etc.], sodium salt of dodecylbenzenesulfonic acid, sodium salt of lauryl alcohol sulfate, fatty acid metal salt, fluorine-containing surfactant and the like.

Examples of ultraviolet absorbers and ultraviolet stabilizers include cinnamic acid derivatives, benzophenone derivatives, triazole derivatives and hindered amine derivatives. Examples of the crosslinking agent include aldehyde compounds such as glyoxal, epoxy compounds, polyamide resins, diglycidyl compounds, aziridine compounds, magnesium chloride and ferric chloride.

As the hindered phenol, a phenol derivative in which at least one ortho position of the phenolic hydroxyl group is substituted with a branched alkyl group is preferable, and 1,1,1,
3-tris (2-methyl-4-hydroxy-5-tert-
Butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl)
Butane, 1,1,3-tris (2-ethyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3
-Tris (3,5-di-tert-butyl-4-hydroxyphenyl) butane, 1,1,3-tris (2-methyl-
4-hydroxy-5-tert-butylphenyl) propane, 2,2′-methylene-bis (6-tert-butyl-4)
-Methylphenol), 2,2'-methylene-bis (6
-Tert-butyl-4-ethylphenol), 1,3,5
-Trimethyl-2,4,6-tris (3,5-di-tert
-Butyl-4-hydroxybenzyl) benzene, 1,
3,5-tris (4-tert-butyl-3-hydroxy-
2,6-Dimethylbenzyl) isocyanuric acid, 1,3
5-tris (4-tert-butyl-3-hydroxy-2-
Methyl-6-ethylbenzyl) isocyanuric acid, bis (2-methyl-4-hydroxy-5-tert-butylphenyl) sulfide and the like can be mentioned.

In the heat-sensitive recording material of the present invention, the method for forming the recording layer is not particularly limited, and the recording layer can be formed according to a conventionally known technique. For example, the coating liquid for the heat-sensitive recording layer is coated on a support with an appropriate coating device such as an air knife coater, a blade coater, a bar coater, a gravure coater, a curtain coater, a short dwell coater, and a wire bar, followed by drying and recording. Layers can be formed. Further, the coating amount of the coating liquid is not particularly limited, and is generally 1.5 to 12 g / m ² , preferably 2.5 to 10 g in dry weight.
Adjusted in the range of / m ² .

As the support, paper, plastic sheet,
Synthetic paper, a composite sheet in which these are combined, a non-woven fabric sheet, or a molded product is used. If necessary, a protective layer (overcoat layer) made of resin or the like may be provided on the front surface and / or the back surface of the thermal recording layer,
Providing an undercoat layer (undercoat layer) composed of a single-layer or multiple-layer pigment (for example, kaolin) or synthetic resin (for example, plastic spherical particles, plastic spherical hollow particles) between the support and the thermosensitive recording layer, It is of course possible to provide an intermediate layer composed of a pigment, a binder or the like between the heat-sensitive recording layer and the undercoat layer or between the heat-sensitive recording layer and the protective layer. Further, the back surface of the support is subjected to an adhesive treatment. Various known techniques in the method of manufacturing a heat-sensitive recording material can be applied. Further, after forming the recording layer, super calendering treatment can be performed.

[0074]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the examples,% represents% by weight. Production Example 1 (Production of Compound of Exemplified Compound No. 22) 4-Phenyloxycarbonylaminosalicylic acid 23.
5 g and 3-hydroxybutanoic acid sodium salt 21.
After adding 7.2 g of sodium hydrogencarbonate to a solution prepared by dissolving 7 g in 140 g of N, N-dimethylformamide, the solution was stirred at 60 ° C. for 6 hours. After the reaction was completed, the reaction solution was discharged into 1500 ml of water, and dilute hydrochloric acid water was added little by little until the pH reached 4. The precipitated solid was filtered and washed with water to give 4- (3′-carboxypropyloxycarbonylamino) salicylic acid 18.1 as a crude product.
g was obtained. The crude product was dissolved in 500 ml of ethyl acetate and the insoluble material was removed by filtration. After the solution was treated with activated carbon, ethyl acetate was distilled off under reduced pressure to give a solid of 5
It was dried at 0 ° C. 4- (3′-carboxypropyloxycarbonylamino) salicylic acid 1 as colorless crystals
4.8 g was obtained. Melting point 197-199 ° C. H ¹ -NMR δ (DMSO-d ₆ ): 1.7-2.6
(M, 4H), 3.9 to 4.3 (m, 2H), 6.8 to
7.8 (m, 3H), 9.8 to 9.9 (s, 1H), 1
1.0-13.0 (br, 2H) FAB-MS m / z = 284 (MH ^<+> ).

Production Example 2 (Production of Zinc Salt / Mono Form of Compound of Exemplified Compound No. 22) To 45.0 g of 4- (3′-carboxypropyloxycarbonylamino) salicylic acid produced in Production Example 1 was added 500 ml of methanol. 250 ml of an aqueous solution in which 13.4 g of sodium hydrogen carbonate was dissolved was added dropwise to the obtained solution, and the mixture was stirred at room temperature for 1 hour. Obtained 4- (3'-
To the solution of the sodium salt of carboxypropyloxycarbonylamino) salicylic acid, zinc sulfate heptahydrate 2
An aqueous solution (750 ml) in which 2.9 g was dissolved was added dropwise at room temperature over 1 hour. After further stirring at room temperature for 1 hour, the precipitated crystals were filtered, washed with water, dried at 40 ° C. for 24 hours, and 46.0 g of zinc salt of 4- (3′-carboxypropyloxycarbonylamino) salicylic acid. Was obtained as colorless crystals. Melting point> 300 ° C

Production Example 3 (Production of Zinc Salt / Di Form of Compound of Exemplified Compound No. 22) To 45.0 g of 4- (3′-carboxypropyloxycarbonylamino) salicylic acid produced in Production Example 1 was added 500 ml of methanol. 500 ml of an aqueous solution in which 26.7 g of sodium hydrogen carbonate was dissolved was added dropwise to the obtained solution, and the mixture was stirred at room temperature for 1 hour. Obtained 4-
(3'-carboxypropyloxycarbonylamino)
To the solution of sodium salt of salicylic acid, 1000 ml of an aqueous solution in which 45.7 g of zinc sulfate heptahydrate was dissolved was added dropwise at room temperature over 1 hour. After further stirring at room temperature for 1 hour, the precipitated crystals were filtered and washed with water, and then at 40 ° C. for 24 hours.
After drying for 4 hours, zinc salt of 4- (3′-carboxypropyloxycarbonylamino) salicylic acid di-body 48.0
g was obtained as colorless crystals. Melting point> 300 ° C

[Evaluation of Thermal Recording Paper] 1. Storage stability test of uncolored part The whiteness of the uncolored part (background) immediately after application of each thermal recording paper prepared in the following Examples and Comparative Examples was measured by a color difference meter (Σ-8).
0, manufactured by Nippon Denshoku Co., Ltd.). As the storage stability test, an oil resistance test and a writing instrument resistance test were performed. The oil resistance test was carried out by overlaying each thermosensitive recording paper with capsule coated paper containing dioctyl phthalate, passing it through a pressure roll, and storing it at 25 ° C for 1 week, and then measuring the whiteness using a color difference meter. did. The larger the numerical value, the better the whiteness of the uncolored portion. After writing with a highlighter pen on the uncolored portion of each thermosensitive recording paper, the resistance to writing instrument test was performed with 25
The whiteness of the uncolored portion after standing for 72 hours at ℃ was visually observed. ○ indicates a state with no stain and high whiteness, and × indicates a state in which it was stained black gray.

2. Storage stability test for colored images Each thermal recording paper was loaded with a thermal paper coloring device (TH-P manufactured by Okura Electric Co., Ltd.
MD) was used to form a color image having a color density of 0.9 measured using a Macbeth densitometer (TR-524 type), and then a storage stability test was performed. As the storage stability test, a moist heat resistance test and an oil resistance test were performed, and the residual ratio of the color image on each thermosensitive recording paper after each test was examined. Moisture and heat resistance test was carried out by applying 2 to each thermosensitive recording paper at 40 ° C and 90% relative humidity.
The color image density after storage for 4 hours was measured using a Macbeth densitometer to determine the residual rate of the color image. The oil resistance test was carried out by using a Macbeth densitometer for the color image density after each thermosensitive recording paper was overlaid with a dioctyl phthalate-containing capsule coated paper, passed through a pressure roll and stored at 25 ° C for 1 week. And the residual rate of the color image was determined. Residual rate (%) = (colored image density after each test / colored image density before test (0.9)) × 100 The larger the value, the better the storage stability of the colored image.

Examples 1 to 16 [Preparation of thermosensitive recording paper] (A liquid composition) Electron-donating color forming compound 10 g 10% aqueous polyvinyl alcohol solution (Kuraray-117) 10 g Water 80 g Total 100 g (B liquid composition) Electron accepting 20g Light calcium carbonate (Okutama industry, TP-123) 40g 10% Polyvinyl alcohol aqueous solution (Kuraray-117) 60g Water 130g Total 250g (C liquid composition) Heat-fusible compound 20g 10% Polyvinyl alcohol aqueous solution (Kuraray) -117) 10 g water 220 g total 250 g The above liquids A, B, and C were dispersed by a sand grinding mill so that the average particle diameter was 1.5 μm to prepare a dispersion liquid. Liquid A 100 g, Liquid B 250 g, Liquid C 2
50 g of the dispersion liquid and 23 g of 30% paraffin wax were mixed, and this was coated on high-quality paper so that the dry coating amount was 5.0 g / m ^2, and dried to prepare a thermosensitive recording paper. The electron-donating color-forming compound, C, in the liquid A used in each example
The benzoic acid derivative represented by the general formula (1) or the metal salt of the derivative used as the heat-fusible compound in the liquid and the electron-accepting compound in the liquid B is shown in Table 1 (Tables 1 and 2). Indicated. In Table 1, the heat-fusible compound a is 2-benzyloxynaphthalene, and the heat-fusible compound b is 1,2-
Bis (3′-methylphenoxy) ethane, the heat-fusible compound c is 4- (4′-methylphenoxy) biphenyl, and the heat-fusible compound d is oxalic acid di (4-methylbenzyl) ester. Represent

[0080]

[Table 1]

[0081]

[Table 2]

Examples 17 to 25 Thermal recording papers were produced in the same manner as in the above examples except that the following liquid D was used instead of liquid B. (D liquid composition) Electron-accepting compound 20 g Zinc oxide 10 g Light calcium carbonate (Okutama industry, TP-123) 30 g 10% polyvinyl alcohol aqueous solution (Kuraray-117) 60 g Water 130 g Total 250 g Electrons in liquid A used The salicylic acid derivative represented by the general formula (1) or the zinc salt of the derivative used as the donor color-forming compound, the heat-fusible compound in the liquid C and the electron-accepting compound in the liquid D is shown in Table 2 (Table 3). )Pointing out toungue. In Table 2, the heat-fusible compound a is 2-benzyloxynaphthalene, and the heat-fusible compound b is 1,2-bis (3′-).
Methylphenoxy) ethane, the heat-fusible compound c is 4
-(4'-methylphenoxy) biphenyl and the heat-fusible compound d represent oxalic acid di (4-methylbenzyl) ester.

[0083]

[Table 3]

Comparative Examples 1 to 5 Liquid A 100 g, liquid B 250 g and liquid C 250 g dispersion were mixed with 30% paraffin wax 23 g, and the dry coating amount of this was 5.0 g / m ^2. Thus, a thermal recording paper was prepared by coating and drying. 2-Benzyloxynaphthalene was used as the heat-fusible compound in the liquid C.
The electron-donating color-forming compound in solution A and the electron-accepting compound in solution B used in each comparative example are shown in Table 3 (Table 4).

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[Table 4] In Table 4 (Table 5) and Table 5 (Table 6), Examples 1 to 1 are shown.
25 and the results of the storage stability test of the uncolored part and the colored image of the thermal recording paper prepared in Comparative Examples 1 to 5 are shown.

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[Table 5]

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[Table 6] As is clear from the results of Tables 4 and 5, the heat-sensitive recording materials containing the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative as the electron-accepting compound of the present invention are Compared with heat-sensitive recording materials, the storage stability of uncolored parts and colored images is excellent.

[0088]

INDUSTRIAL APPLICABILITY The salicylic acid derivative of the present invention has a structure having two carboxyl groups in the same molecule and uses a metal salt as an electron-accepting compound of a heat-sensitive recording material, and is excellent in storage stability of an uncolored portion and a colored image. Can be provided. Further, not only can various metal salts be provided as a recording material as a compound having two carboxyl groups in the same molecule, but also industrially, various applications can be expected.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C09K 9/02 C

Claims (4)

[Claims] 1. A salicylic acid derivative represented by the general formula (1). Embedded image (In the formula, X ₁ and X ₂ represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y represents an alkylene group, and Z represents an oxygen atom or a sulfur atom.) 2. A metal salt of a salicylic acid derivative represented by the general formula (1) according to claim 1. 3. A thermosensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, wherein the electron-accepting compound is at least one salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative. Thermal recording material containing. Embedded image (In the formula, X ₁ and X ₂ represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y represents an alkylene group, and Z represents an oxygen atom or a sulfur atom.) 4. The heat-sensitive recording material according to claim 3, further comprising a metal compound.