JP2005074948A - Thermosensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosensitive recording material, which is excellent in preservability before recording and hue, undergoes a small color change in light exposure in light displaying and is excellent in the preservability of the image in a recording part. <P>SOLUTION: In the thermosensitive recording material, in which a thermosensitive recording layer including a diazo compound and a coupler compound, which forms color by reaction with the diazo compound, on a support, the coupler compound includes an anilide derivative expressed by general formula (1) or at least one kind of its tautomers. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-sensitive recording material utilizing the photosensitivity of a diazo compound. More specifically, the present invention relates to a yellow color-type heat-sensitive recording material having improved color development and pre-recording storage stability.

Along with the improvement in performance of thermal recording materials, there is a strong demand for thermal recording materials using diazo compounds and coupler compounds that have yellow color development, improved storage stability before recording, and improved color density. ing.
Recording materials that utilize the photosensitivity of diazo compounds can be broadly classified into three types: wet development type, dry development type, and thermal development type. Among these types, thermal development type is either wet or dry type. On the other hand, there is an advantage in maintenance because no developer is required.

  On the other hand, it is necessary for the heat-sensitive recording material to suppress as much as possible the phenomenon such as the background portion being colored during storage before recording or the color density decreasing. Here, when designing a material that can sufficiently develop color and obtain a high concentration even when the heating temperature is low, it is natural that a coloring reaction may occur even during storage at room temperature before recording, It appears as a phenomenon in which the background portion that must be white is colored.

  In order to solve the above-mentioned problems, a photosensitive material using a specific anilide derivative as a coupler compound has been proposed. However, although the photosensitive material has an effect of improving storage stability, it cannot satisfy image light resistance. (For example, refer to Patent Document 1).

In addition, a heat-sensitive recording material using an anilide derivative having a specific functional group introduced into an oil-soluble group as a coupler compound has been proposed. The heat-sensitive recording material has a certain effect on the color density and the preservation of the background portion. However, further improvement is desired (for example, see Patent Documents 2 to 4).
Thus, at present, a heat-sensitive recording material that has a yellow color development property, suppresses background coloring during storage before recording, and simultaneously satisfies excellent image light resistance has not yet been obtained.
Japanese Patent Publication No.54-3363 JP-A-9-160168 JP 9-216468 A JP-A-9-216469

  The present invention has been made in view of the above-mentioned facts, and is excellent in preservability (raw preservation) and hue before recording, small in exposure coloration, and excellent in image preservability (light fastness) of a recording portion. The purpose is to provide material.

In order to achieve the above-mentioned object, the present inventors have focused on the coupler compound and further the diazo compound, and as a result of intensive studies, the heat-sensitive recording material obtained by the following means is capable of maintaining the raw texture and image of the background. The inventors found that the light resistance was improved and the yellow color development was excellent, and the present invention was completed.
That is, the present invention

<1> In a thermosensitive recording material provided with a thermosensitive recording layer containing a diazo compound and a coupler compound that reacts with the diazo compound and develops color on the support, the coupler compound is represented by the following general formula (1). A heat-sensitive recording material comprising at least one of the above-mentioned anilide derivatives or tautomers thereof.

(In the general formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom, halogen atom, alkyl group, aryl group, acyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, carboxyl group, An aminocarbonyl group, an acylamino group, an aminosulfonyl group, a sulfonamido group, a cyano group, a nitro group, an arylthio group, or an alkylthio group, R ⁴ , R ⁵ , R ^6, and R ⁷ are each independently a hydrogen atom, an alkyl A group, an aryl group, an alkoxycarbonyl group, or an amide group, R ⁴ and R ⁵ may be bonded to each other to form a ring, and Z is —S—, —O—, or —N (R ⁸ )-, R ⁸ represents a hydrogen atom, an alkyl group, or an aryl group, m represents 1 or 2, and n represents 1 or 2.

<2> R ¹ , R ² and R ³ in the general formula (1) are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an acylamino group. The heat-sensitive recording material according to <1>, which represents a group, a cyano group, a nitro group, an arylthio group, or an alkylthio group.

<3> The heat-sensitive recording material according to <1> or <2>, wherein the diazo compound is a diazo compound represented by the following general formula (2).

(In General Formula (2), R ¹¹ and R ¹³ each independently represents an alkyl group, an aryl group, a heterocyclic group, or an acyl group. R ¹² represents an alkyl group, an aryl group, an alkylsulfonyl group, or an arylsulfonyl group. Y ¹ represents an oxygen atom, a sulfur atom, or an amino group, Y ² represents an oxygen atom, a sulfur atom, or a single bond, Y ³ represents an oxygen atom, a sulfur atom, Or a hydrogen atom and when Y ³ is hydrogen, R ¹³ does not exist, R ¹¹ and R ¹³ may be bonded to each other to form a ring, and X ⁻ represents an anion.)

<4> The heat-sensitive recording material according to <3>, wherein the diazo compound is a diazo compound represented by the following general formula (3).

(In the general formula (3), R ²¹ , R ²² and R ²³ each independently represents an alkyl group or an aryl group, and X ⁻ represents an anion.)

<5> The heat-sensitive recording material according to <3>, wherein the diazo compound is a diazo compound represented by the following general formula (4).

(In the general formula (4), each R ^31, R ³² and R ³³ are independently an alkyl group or an aryl group bonded to each other with .R ³² and R ³³ may form a ring .X ^- Represents an anion.)

<6> The heat-sensitive recording material according to any one of <1> to <5>, wherein the diazo compound is encapsulated in a microcapsule.
<7> The heat-sensitive recording material according to <6>, wherein the capsule wall forming the microcapsule is a capsule wall containing polyurethane and / or polyurea as a constituent component.
<8> The heat-sensitive recording material according to any one of <1> to <7>, further comprising a basic substance.

  INDUSTRIAL APPLICABILITY The present invention can provide a heat-sensitive recording material that has excellent storage stability (raw storage stability) and hue before recording, small exposure coloration, and excellent image storage stability (light fastness) of the recording area.

The heat-sensitive recording material of the present invention is a heat-sensitive recording material provided with a heat-sensitive recording layer containing a diazo compound and a coupler compound that reacts with the diazo compound and develops color on the support. It contains at least one kind of anilide derivative represented by the formula (1) or a tautomer thereof.
In the present invention, the tautomer exists as an isomer of the anilide derivative represented by the general formula (1) and has a relationship in which the structure easily changes between the two. Say.

In the general formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom, halogen atom, alkyl group, aryl group, acyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, carboxyl group, An aminocarbonyl group, an acylamino group, an aminosulfonyl group, a sulfonamide group, a cyano group, a nitro group, an arylthio group, or an alkylthio group is represented. R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxycarbonyl group or an amide group, and R ⁴ and R ⁵ are bonded to each other to form a ring. It may be. Z is -S -, - O-or -N (R ⁸⁾ - represents, R ⁸ represents a hydrogen atom, an alkyl group, or an aryl group. m represents 1 or 2. n represents 1 or 2.

(Thermosensitive recording layer)
The heat-sensitive recording layer in the invention contains a diazo compound and at least one of the anilide derivative represented by the general formula (1) or a tautomer thereof as a coupler compound that reacts with the diazo compound and develops color.

[Coupler compound]
First, the anilide derivative represented by the general formula (1) in the present invention will be described.
In the said General formula (1), a chlorine atom, a fluorine atom, a bromine atom, etc. are mentioned as a halogen atom represented by R < ¹ >, R < ² > and R < ³ >, A chlorine atom is preferable.

In the general formula (1), the alkyl group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The alkyl group represented by R ¹ , R ² and R ³ is preferably an alkyl group having 1 to 10 carbon atoms in total, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, 1 -A methylcyclopropyl group, 1-ethylcyclopropyl group, a trifluoromethyl group, etc. are mentioned, A methyl group, t-butyl group, 1-methylcyclopropyl group, or a trifluoromethyl group is preferable.

In the general formula (1), the aryl group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The aryl group represented by R ¹ , R ² and R ³ is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group, a tolyl group, and a methoxyphenyl group. preferable.

In the general formula (1), the acyl group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The acyl group represented by R ¹ , R ² and R ³ is preferably an acyl group having 2 to 18 carbon atoms, and examples thereof include an acetyl group, a pivaloyl group, an octanoyl group, and a stearoyl group. Group, pivaloyl group or octanoyl group is preferred.

In the general formula (1), the alkoxy group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
As the alkoxy group represented by R ¹ , R ² and R ³ , an alkoxy group having 1 to 18 carbon atoms is preferable. For example, methoxy group, ethoxy group, butoxy group, octyloxy group, nonyloxy group, dodecyloxy Group, 2-methoxyethoxy group, or 2-phenoxyethoxy group, and the like, and a methoxy group, a butoxy group, a nonyloxy group, or a dodecyloxy group is preferable.

In the general formula (1), the alkoxycarbonyl group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, Preferable examples include an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The alkoxycarbonyl group represented by R ¹ , R ² and R ³ is preferably an alkoxycarbonyl group having 1 to 19 carbon atoms in total, for example, a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, an octyloxycarbonyl group. 2-ethylhexyloxycarbonyl group, nonyloxycarbonyl group, decyloxycarbonyl group, 3,5,5-trimethylhexyl group, 3,7-dimethyloctyloxycarbonyl group, dodecyloxycarbonyl group, 2-methoxyethoxycarbonyl Group, a 2-phenoxyethoxycarbonyl group, and the like, and a butoxycarbonyl group, a nonyloxycarbonyl group, a decyloxycarbonyl group, or a dodecyloxycarbonyl group is preferable.

In the general formula (1), the aminocarbonyl group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, Preferable examples include an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The aminocarbonyl group represented by R ¹ , R ² and R ³ is preferably an aminocarbonyl group having 1 to 19 carbon atoms in total, for example, methylaminocarbonyl group, dimethylaminocarbonyl group, butylaminocarbonyl group, dibutyl An aminocarbonyl group, an octylaminocarbonyl group, a decylaminocarbonyl group, a dodecylaminocarbonyl group, a-(4-methyldiphenyl) aminocarbonyl group, an aminocarbonyl group, etc. are mentioned, and a dimethylaminocarbonyl group or a dibutylaminocarbonyl group preferable.

In the general formula (1), the acylamino group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The acylamino group represented by R ¹ , R ² and R ³ is preferably an acylamino group having 1 to 18 carbon atoms in total, such as an acetylamino group, a pivaloylamino group, an octanoylamino group, or a stearoylamino group. And an acetylamino group, a pivaloylamino group, or an octanoylamino group is preferable.

In the general formula (1), the arylthio group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The arylthio group represented by R ¹ , R ² and R ³ is preferably an arylthio group having 6 to 18 carbon atoms in total, for example, phenylthio group, tritylthio group, naphthylthio group, 2-chlorophenylthio group, 4-chlorophenyl. Examples include a thio group, a 4-nitrophenylthio group, or a 4-acetylaminophenylthio group, and a phenylthio group, a tritylthio group, or a 4-chlorophenylthio group is preferable.

In the general formula (1), the alkylthio group represented by R ¹ , R ² and R ³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. Preferred examples include a group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The alkylthio group represented by R ¹ , R ² and R ³ is preferably an alkylthio group having 1 to 12 carbon atoms in total, such as a methylthio group, an ethylthio group, a butylthio group, an octylthio group, or a dodecylthio group. And a methylthio group, a butylthio group, or a dodecylthio group is preferred.

As R ¹ , R ² and R ³ in the general formula (1), a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an aminocarbonyl group, an acylamino group, a cyano group, A nitro group, an arylthio group, or an alkylthio group is preferred.

In the general formula (1), the alkyl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, Preferable examples include an atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
Examples of the alkyl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, and a hexyl group. Cyclohexyl group, heptyl group, octyl group, 2-ethylhexyl group, decyl group, dodecyl group, octadecyl group, 2-hydroxyethyl group, 2-benzoyloxyethyl group, 2- (4-butoxyphenoxy) ethyl group, benzyl group Allyl group, methoxyethyl group, ethoxyethyl group, or dibutylaminocarbonylmethyl group is preferred.

In the general formula (1), the aryl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, Preferable examples include an atom, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group.
The aryl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ is particularly preferably a phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, or a 4-butoxyphenyl group.

In the general formula (1), the alkoxycarbonyl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ may further have a substituent. Examples of the substituent include an alkoxy group, Preferable examples include an aryloxy group, an alkylthio group, an arylthio group, a halogen atom, or an acylamino group.
Examples of the alkoxycarbonyl group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ include a methoxycarbonyl group, a butoxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an ethoxyethoxycarbonyl group, or a chloroethoxycarbonyl group. preferable.

In the general formula (1), the amide group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ may further have a substituent. Examples of the substituent include an alkyl group, aryl Preferred examples include a group, an alkylthio group, or an arylthio group.
As the amide group represented by R ⁴ , R ⁵ , R ⁶ and R ⁷ , in particular, N, N-diethylamide group, N, N-dibutylamide group, N, N-dioctylamide group, N-ethyl- N-phenylamide group or N-octylamide group is preferred.

R ⁴ and R ⁵ may be connected to each other to form a ring. Examples of the ring thus formed include a piperidine ring, a pyrrolidine ring, a morpholine ring, and a thiomorpholine ring.

R ⁴ , R ⁵ , R ⁶ and R ⁷ in the general formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 25 carbon atoms, or 2 carbon atoms. It is preferably ˜20 alkoxycarbonyl group or amide group having 2 to 20 carbon atoms.

Z in the general formula (1) represents —S—, —O—, or —NR ⁸ , and R ⁸ represents a hydrogen atom, an alkyl group, or an aryl group.
Preferred examples of the alkyl group and aryl group for R ⁸ are the same as those for R ⁴ , R ⁵ , R ⁶ and R ⁷ described above.
Z in the general formula (1) is preferably -S- or -O-.

  Specific examples (exemplary compounds (A-1) to (A-49)) of anilide derivatives represented by the general formula (1) are shown below, but the present invention is not limited thereto.

  The total content of the anilide derivative represented by the general formula (1) in the thermosensitive recording layer is preferably 0.2 to 8 mol, more preferably 0.5 to 4 mol, relative to 1 mol of the diazo compound. When the total content of the coupler is 0.2 to 8 mol with respect to 1 mol of the diazo compound, more sufficient color development is obtained, and the coating suitability is further improved.

  In addition, in the present invention, in addition to the azolinyl acetic acid derivative represented by the general formula (1), for the purpose of adjusting the hue or the like, a known dye is formed by coupling with a diazo compound in a basic atmosphere as necessary. A coupler can also be used in combination. When the azolinyl acetic acid derivative represented by the general formula (1) is used in combination with a known coupler, 50% by mass or more of all the couplers contained in the recording layer is the azolinyl acetic acid derivative represented by the general formula (1). It is preferably 70% by mass or more.

  Examples of the known couplers include so-called active methylene compounds having a methylene group next to a carbonyl group, phenol derivatives, naphthol derivatives, and the like.

  Specific examples of the known coupler include resorcin, phloroglucin, sodium 2,3-dihydroxynaphthalene-6-sulfonate, 1-hydroxy-2-naphthoic acid morpholinopropylamide, 1,5-dihydroxynaphthalene, 2,3 -Dihydroxynaphthalene, 2,3-dihydroxy-6-sulfo-naphthalene, 2-hydroxy-3-naphthoic acid morpholinopropylamide, 2-hydroxy-3-naphthoic acid octylamide, 2-hydroxy-3-naphthoic acid anilide, benzoyl Acetonilide, 1-phenyl-3-methyl-5-pyrazolone, 1- (2,4,6-trichlorophenyl) -3-anilino-5-pyrazolone, 2- {3- [α- (2,4- Di-tert-amylphenoxy) -butanamide] ben ヅ amide} phenol 2,4-bis - (benzoylacetonate amino) toluene, 1,3-bis - (pivaloyl acetamide aminomethyl) include benzene and the like.

(Diazo compound)
The diazo compound used in the recording layer in the present invention is not particularly limited, but it is preferable to use a diazo compound represented by the following general formula (2).

In the general formula (2), R ¹¹ and R ¹³ each independently represents an alkyl group, an aryl group, a heterocyclic group, or an acyl group. R ¹² represents an alkyl group, an aryl group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, or a heterocyclic group. Y ¹ represents an oxygen atom, a sulfur atom, or an amino group, Y ² represents an oxygen atom, a sulfur atom, or a single bond, and Y ³ represents an oxygen atom, a sulfur atom, or a hydrogen atom. However, when Y ³ is a hydrogen atom, R ¹³ does not exist. R ¹¹ and R ¹³ may combine with each other to form a ring. X ⁻ represents an anion.

In the general formula (2), R ¹¹ and R ¹³ are preferably an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an acyl group having 2 to 20 carbon atoms.
The alkyl group represented by R ¹¹ or R ¹³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, An acylamino group, carbamoyl group, cyano group, carboxylic acid group, sulfonic acid group, or heterocyclic group is preferred.

As the alkyl group represented by R ¹¹ or R ¹³ , in particular, methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, pentyl group, 3-pentyl group, cyclopentyl group, hexyl group, cyclohexyl Group, heptyl group, octyl group, 2-ethylhexyl group, decyl group, dodecyl group, octadecyl group, 2-hydroxyethyl group, 2-benzoyloxyethyl group, 2- (4-butoxyphenoxy) ethyl group, benzyl group, allyl group Group, methoxyethyl group, ethoxyethyl, or dibutylaminocarbonylmethyl group is preferred.

The aryl group represented by R ¹¹ or R ¹³ may further have a substituent, and examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, and an acyloxy group. An acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group is preferred.
As the aryl group represented by R ¹¹ or R ¹³ , a phenyl group, a 4-methoxyphenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, a 4-butoxyphenyl group, or a naphthyl group is particularly preferable.

When R ¹¹ or R ¹³ is a heterocyclic group, the heterocyclic ring preferably has nitrogen, oxygen, or sulfur as a hetero atom, and any of saturated, unsaturated, monocyclic, and condensed rings Good. Specific examples include furyl, thienyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, pyridyl, pyrimidyl, morpholinyl, piperazinyl, indolyl, isoindolyl and the like. Furthermore, these heterocyclic groups may have a substituent. Examples of the substituent include the same ones as described above for the alkyl group.

The acyl group represented by R ¹¹ or R ¹³ may be aliphatic, aromatic or heterocyclic, and may further have a substituent. As the substituent, an alkoxy group, an aryloxy group, or a halogen atom is preferable.
As the acyl group represented by R ¹¹ or R ¹³ , an acetyl group, a propanoyl group, a hexanoyl group, a benzoyl group, or the like is particularly preferable.

R ¹¹ and R ¹³ may be bonded to each other to form a ring. Examples of the ring in which R ¹¹ and R ¹³ are bonded include a thiazole ring, an oxazole ring, or an imidazole ring, and these may further have a substituent. Examples of the substituent include the same ones as described above for the alkyl group.

In the general formula (2), R ¹² is preferably an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an acyl group having 2 to 20 carbon atoms.
The alkyl group in R ^12, an aryl group, the heterocyclic group and acyl group, wherein R ¹¹ and R ¹³ alkyl group in an aryl group, a heterocyclic group, and include the same ones as the acyl group.

The alkylsulfonyl group represented by R ¹² may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, and an acylamino group. , A carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group is preferable.

Examples of the alkylsulfonyl group represented by R ¹² include a methylsulfonyl group, an ethylsulfonyl group, a butylsulfonyl group, a hexylsulfonyl group, a decylsulfonyl group, a benzylsulfonyl group, and a methoxybutylsulfonyl group.

The arylsulfonyl group represented by R ¹² may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, and an acylamino group. , A carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group is preferable.

Examples of the arylsulfonyl group represented by R ¹² include a phenylsulfonyl group, a naphthylsulfonyl group, a 4-chlorophenylsulfonyl group, and a 4-methylphenylsulfonyl group.

In the general formula (2), Y ¹ is preferably a sulfur atom or an amino group, and when Y ¹ is an amino group, it may further have a substituent. Examples of the substituent include an alkyl group and an aryl group.
Y ¹ and R ¹¹ may form a ring. Examples of the ring formed by Y ¹ and R ¹¹ include pyrrolidinyl, piperidinyl, piperazinyl, indolyl group and the like, and these may further have a substituent. Examples of the substituent include the same ones as described above for the alkyl group.

In the general formula (2), Y ² is preferably a sulfur atom or an oxygen atom. Similarly, Y ³ is preferably a sulfur atom or an oxygen atom.

Examples of the anion represented by X ⁻ in the general formula (2) include inorganic anions and organic anions. As the inorganic anion, hexafluorophosphate ion, borohydrofluoric acid ion, chloride ion, and sulfate ion are preferable, and hexafluorophosphate ion and borohydrofluoric acid ion are particularly preferable. As the organic anion, polyfluoroalkylcarboxylate ions, polyfluoroalkylsulfonate ions, tetraphenylborate ions, aromatic carboxylate ions, and aromatic sulfonate ions are particularly preferable.

  The diazo compound represented by the general formula (2) is preferably a diazo compound represented by the following general formula (3) or general formula (4).

In the general formula (3), R ²¹ and R ²² each independently represents an alkyl group or an aryl group, and R ²³ represents a hydrogen atom, an alkyl group, or an aryl group. X ⁻ represents an anion. In the general formula (4), R ³¹ , R ³² and R ³³ each independently represents an alkyl group or an aryl group. R ³² and R ³³ may be bonded to each other to form a ring. X ⁻ represents an anion.

R ²¹ , R ²² and R ²³ in the general formula (3) are preferably an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms.
The alkyl group represented by R ²¹ , R ²² and R ²³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, an alkoxy group, an aryloxy group, and an alkoxycarbonyl group. An acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group or a heterocyclic group is preferred.

As the alkyl group represented by R ²¹ , R ²² and R ²³ , methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, Heptyl, octyl, 2-ethylhexyl, decyl, dodecyl, octadecyl, 2-hydroxyethyl, 2-benzoyloxyethyl, 2- (4-butoxyphenoxy) ethyl, benzyl, allyl, A methoxyethyl group, an ethoxyethyl group, and a dibutylaminocarbonylmethyl group are preferred.

In the general formula (3), the aryl group represented by R ²¹ , R ²² and R ²³ may further have a substituent. Examples of the substituent include a phenyl group, a halogen atom, and an alkoxy group. An aryloxy group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, a carbamoyl group, a cyano group, a carboxylic acid group, a sulfonic acid group, or a heterocyclic group is preferable.
As the aryl group represented by R ²¹ , R ²² , and R ²³ , a phenyl group, a 4-chlorophenyl group, a 4-methylphenyl group, and a 4-butoxyphenyl group are particularly preferable.

X in the general formula (3) ^- is, X in the general formula (2) ^- it is the same meaning, include those similar.

Preferred examples of the alkyl group, aryl group, and X ⁻ represented by R ³¹ , R ³² , and R ³³ in the general formula (4) are R ²¹ , R ²² , and R ²³ in the general formula (3). And an alkyl group, an aryl group, and the same as those represented by X ⁻ are represented. R ³² and R ³³ may be bonded to each other to form a ring, and examples of the ring formed by R ³² and R ³³ include a morpholine ring, a piperidine ring, and a pyrrolidine ring.

  Specific examples (exemplary compounds (D-1) to (D-92)) of the diazo compound compounds represented by the general formulas (2) to (4) are shown below, but the present invention is limited thereto. is not.

~ Diazo compound represented by formula (2) ~

-Diazo compound represented by general formula (3)-

~ Diazo compound represented by formula (4) ~

  The diazo compounds represented by the general formulas (2) to (4) may be used alone or in combination of two or more. Further, according to various purposes such as hue adjustment, the diazo compound represented by the general formulas (2) to (4) and a known diazo compound may be used in combination. When the diazo compound represented by the general formulas (2) to (4) and the known diazo compound are used in combination, the diazo compound represented by the general formulas (2) to (4) is contained in the recording layer. It is preferable that it is 50 mass% or more of a diazo compound, and it is preferable that it is 80 mass% or more.

  Examples of the known diazo compounds include 4-diazo-1-dimethylaminobenzene, 4-diazo-2-butoxy-5-chloro-1-dimethylaminobenzene, 4-diazo-1-methylbenzylaminobenzene, 4-diazo. -1-ethylhydroxyethylaminobenzene, 4-diazo-1-diethylamino-3-methoxybenzene, 4-diazo-1-morpholinobenzene, 4-diazo-1-morpholino-2,5-dibutoxybenzene, 4-diazo -1-Toluyl mercapto-2,5-diethoxybenzene, 4-diazo-1-piperazino-2-methoxy-5-chlorobenzene, 4-diazo-1- (N, N-dioctylaminocarbonyl) benzene, 4- Diazo-1- (4-tert-octylphenoxy) benzene, 4-diazo-1- (2-ethyl Sanoylpiperidino) -2,5-dibutoxybenzene, 4-diazo-1- [α- (2,4-ditert-amylphenoxy) butyrylpiperidino] benzene, 4-diazo-1- (4 -Methoxy) phenylthio-2,5-diethoxybenzene, 4-diazo-1- (4-methoxy) benzamide-2,5-diethoxybenzene, 4-diazo-1-pyrrolidino-2-methoxybenzene and the like are preferable.

  Further, in the heat-sensitive recording material of the present invention, in order to improve the raw storage stability before use of the heat-sensitive recording material, it is preferable to encapsulate a diazo compound in a microcapsule as described in detail later. In that case, since it is used by dissolving in an appropriate solvent, the diazo compound preferably has an appropriate solubility in these solvents and low water solubility. Specifically, it has a solubility of 5% or more with respect to the organic solvent to be used, and the solubility in water is preferably 1% or less.

In the heat-sensitive recording material of the present invention, the diazo compound is preferably contained in the recording layer in the range of 0.02 to 3 g / m ² , and particularly in the range of 0.1 to ² g / m ² from the viewpoint of color density. It is preferable to contain.

(Microcapsule)
In the heat-sensitive recording material of the present invention, it is preferable to encapsulate a diazo compound in a microcapsule in order to improve the raw storage stability before use.
The microcapsules used in this case are prepared by dissolving a diazo compound in a non-aqueous solvent having a boiling point of 40 to 95 ° C. under normal pressure and a solution in which the same or different compound that reacts with each other to form a polymer substance is dissolved. After emulsifying and dispersing in the hydrophilic protective colloid solution, the temperature of the solution is raised while reducing the pressure of the reaction vessel to move the wall-forming substance to the surface of the oil droplets while distilling off the solvent. It is produced by forming a wall film by advancing a polymer formation reaction by polycondensation.

  In the heat-sensitive recording material of the present invention, it is particularly preferable to use microcapsules which are substantially free of a solvent, which will be described later, from the viewpoint of obtaining a good shelf life. The microcapsule wall is more preferably a microcapsule wall containing polyurethane and / or polyurea as a constituent component.

Hereinafter, a method for producing a diazo compound-containing microcapsule (polyurea / polyurethane wall) in the heat-sensitive recording material of the present invention will be described.
First, the diazo compound is dissolved in a hydrophobic organic solvent that becomes the core of the capsule. As the hydrophobic organic solvent used in this case, an organic solvent having a boiling point of 100 ° C. to 300 ° C. is preferable. Aromatic hydrocarbons, halogenated hydrocarbons, carboxylic acid esters, phosphate esters, sulfate esters, Examples include sulfonic acid esters, ketones, and ethers. Specific examples of the organic solvent include alkyl naphthalene, alkyl diphenyl ethane, alkyl diphenyl methane, alkyl biphenyl, chlorinated paraffin, trixyl phosphate, tricresyl phosphate, maleic acid dioctyl ester, adipic acid dibutyl ester and the like. These may be used individually by 1 type and may use 2 or more types together.
Moreover, when the solubility of the diazo compound to be encapsulated in the organic solvent is poor, a low-boiling solvent having high solubility in the diazo compound can be used in combination. Specific examples of the low boiling point solvent include ethyl acetate, butyl acetate, methylene chloride, tetrahydrofuran, and acetone. Further, a polyvalent isocyanate is further added as a wall material (oil phase) in the hydrophobic organic solvent that becomes the core of the microcapsule.

  On the other hand, as the aqueous phase, an aqueous solution in which a water-soluble polymer such as polyvinyl alcohol or gelatin is dissolved is prepared, and then the oil phase is added and emulsified and dispersed by means such as a homogenizer. At this time, the water-soluble polymer acts as a stabilizer for emulsion dispersion. In order to carry out emulsification and dispersion more stably, a surfactant may be added to at least one of the oil phase and the aqueous phase.

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

  If a polyol is added to the aqueous phase, the polyvalent isocyanate and the polyol can react to form a polyurethane wall. In order to increase the reaction rate, it is preferable to keep the reaction temperature high or to add an appropriate polymerization catalyst. The polyisocyanate, polyol, reaction catalyst, polyamine for forming a part of the wall agent, etc. are well known in the book (Keiji Iwata, Polyurethane Handbook, Nikkan Kogyo Shimbun (1987)).

  The polyvalent isocyanate compound used as the raw material for the microcapsule wall is preferably a compound having a trifunctional or higher functional isocyanate group, but a bifunctional isocyanate compound may be used in combination. Specifically, xylene diisocyanate and its hydrogenated product, hexamethylene diisocyanate, tolylene diisocyanate and its hydrogenated product, and diisocyanates such as isophorone diisocyanate are used as the main raw materials, and these dimers or trimers (burette or isosinurate). In addition, polyfunctional adducts with polyols such as trimethylolpropane, formalin condensates of benzene isocyanate, and the like.

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

  The water-soluble polymer used in the water-soluble polymer aqueous solution for dispersing the oil phase of the capsule thus prepared is preferably a water-soluble polymer having a water solubility of 5 or more at the temperature to be emulsified. As polyvinyl alcohol and its modified products, polyacrylic acid amide and its derivatives, ethylene-vinyl acetate copolymer, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer. Examples include polymers, polyvinylpyrrolidone, ethylene-acrylic acid copolymers, vinyl acetate-acrylic acid copolymers, carboxymethylcellulose, methylcellulose, casein, gelatin, starch derivatives, arabic gum, and sodium alginate.

  These water-soluble polymers preferably have no or low reactivity with isocyanate compounds. For example, those having a reactive amino group in the molecular chain, such as gelatin, can be modified by modification beforehand. It is necessary to eliminate this. Moreover, when adding surfactant, it is preferable that the addition amount of surfactant is 0.1%-5% with respect to the mass of an oil phase, especially 0.5%-2%.

  For emulsification, a known emulsification apparatus such as a homogenizer, a manton gorey, an ultrasonic disperser, or a teddy mill can be used. After emulsification, the emulsion is heated to 30 to 70 ° C. in order to promote the capsule wall formation reaction. Further, during the reaction, in order to prevent aggregation between the capsules, it is necessary to add water to reduce the collision probability between the capsules or to perform sufficient stirring.

  Further, a dispersing agent for preventing aggregation may be added again during the reaction. As the polymerization reaction proceeds, the generation of carbon dioxide gas is observed, and its end can be regarded as the approximate end point of the capsule wall formation reaction. Usually, the target diazo compound-containing microcapsules can be obtained by reacting for several hours.

(Basic substance)
In the heat-sensitive recording material of the present invention, a basic substance may be added for the purpose of promoting the coupling reaction between the diazo compound and the coupler.
These basic substances can be used alone or in combination of two or more. Examples of the basic substance include nitrogen-containing compounds such as tertiary amines, piperidines, piperazines, amidines, formamidines, pyridines, guanidines and morpholines.

  Among these, in particular, N, N′-bis (3-phenoxy-2-hydroxypropyl) piperazine, N, N′-bis [3- (p-methylphenoxy) -2-hydroxypropyl] piperazine, N, N '-Bis [3- (p-methoxyphenoxy) -2-hydroxypropyl] piperazine, N, N'-bis (3-phenylthio-2-hydroxypropyl) piperazine, N, N'-bis [3- (β- Naphthoxy) -2-hydroxypropyl] piperazine, N-3- (β-naphthoxy) -2-hydroxypropyl-N′-methylpiperazine, 1,4-bis {[3- (N-methylpiperazino) -2-hydroxy] Piperazines such as propyloxy} benzene, N- [3- (β-naphthoxy) -2-hydroxy] propylmorpholine, 1,4-bis [(3- Morpholines such as morpholino-2-hydroxy) propyloxy] benzene, 1,3-bis [(3-morpholino-2-hydroxy) propyloxy] benzene, N- (3-phenoxy-2-hydroxypropyl) piperidine, N -Piperidines such as dodecylpiperidine, guanidines such as triphenylguanidine, tricyclohexylguanidine, dicyclohexylphenylguanidine and the like are preferable.

  In the heat-sensitive recording material of the present invention, the amount of the basic substance used relative to 1 part by mass of the diazo compound is preferably 0.1 to 30 parts by mass.

(Coloring aid)
In the present invention, in addition to the organic base described above, a coloring aid can be added for the purpose of promoting the coloring reaction. The color assistant is a substance that increases the color density during heat recording or lowers the minimum color development temperature, lowers the melting point of couplers, basic substances, diazo compounds, etc., or softens the capsule wall. This is intended to create a situation in which diazo compounds, basic substances, couplers, etc. are likely to react by the action of lowering the amount of water.

  As a color developing aid used in the heat-sensitive recording material of the present invention, for example, a phenol derivative, a naphthol derivative, an alkoxy-substituted benzene, an alkoxy-substituted naphthalene, Hydroxy compounds, amide compounds, sulfonamide compounds and the like can be added. These compounds are considered to reduce the melting point of couplers and basic substances, or to improve the heat permeability of the microcapsule wall, thereby enabling a high color density.

  The color forming aid used in the heat-sensitive recording material of the present invention may be a heat-meltable substance. The heat-melting substance is a substance having a melting point of 50 ° C. to 150 ° C. that is solid at normal temperature and melts by heating, and is a substance that dissolves a diazo compound, a coupler, a basic substance, or the like. Specific examples of these compounds include carboxylic acid amides, N-substituted carboxylic acid amides, ketone compounds, urea compounds, esters and the like.

(Other additives)
In the heat-sensitive recording material of the present invention, the following known antioxidants are used for the purpose of improving fastness to light and heat of a thermochromic image or reducing yellowing due to light in an unprinted portion after fixing. Etc. are preferably used.

  Examples of the antioxidant include, for example, European Patent Publication No. 223739, Publication No. 309401, Publication No. 309402, Publication No. 310551, Publication No. 310552, Publication No. 457416, and Publication of German Publication No. No. 3435443, JP-A-54-48535, JP-A-62-262047, JP-A-63-113536, JP-A-63-163351, JP-A-2-262654, JP-A-2-71262, JP-A-3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275 and the like.

  Furthermore, it is also effective to use various known additives already used in heat-sensitive recording materials and pressure-sensitive recording materials. Specific examples of these antioxidants include JP-A-60-107384, JP-A-60-107383, JP-A-60-125470, JP-A-60-125471, JP-A-60-125472, and JP-A-60. -287485, 60-287486, 60-287487, 60-287488, 61-160287, 61-185483, 61-2111079, 62- 146678, 62-146680, 62-146679, 62-28285, 63-051174, 63-89877, 63-88380, 63-088381 Gazette, 63-203372 gazette, 63-224989 gazette, 63-251 gazette. No. 82, No. 63-267594, No. 63-182484, JP-A-01-239282, No. 04-291658, No. 04-291684, No. 05-188687, No. 05- 188686, 05-110490, 05-1108437, 05-170361, Japanese Patent Publication No. 48-033294, 48-033212, and the like. it can.

  Specifically, 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2-dihydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2-dihydroquinoline 6-ethoxy-1-phenyl-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline, 6-ethoxy-1-octyl-2,2,4-trimethyl-1,2,3 4-tetrahydroquinoline, nickel cyclohexaneate, 2,2-bis-4-hydroxyphenylpropane, 1,1-bis-4-hydroxyphenyl-2-ethylhexane, 2-methyl-4-methoxy-diphenylamine, 1-methyl -2-phenylindole and the like.

  The addition amount of these antioxidants is preferably 0.05 to 100 parts by mass, particularly preferably 0.2 to 30 parts by mass with respect to 1 part by mass of the diazo compound. The above-mentioned known antioxidants can be used in a microcapsule together with a diazo compound, or can be used as a solid dispersion or with a suitable emulsifying aid together with a coupling component, a basic substance, or other coloring aid. It can be used in the form of an emulsion or in both forms. Of course, one or more antioxidants can be used in combination. Further, a protective layer can be provided on the recording layer, and the protective layer can be added or exist.

  These antioxidants need not be added to the same layer. When these antioxidants are used in combination, they are structurally classified as anilines, alkoxybenzenes, hindered phenols, hindered amines, hydroquinone derivatives, phosphorus compounds, sulfur compounds, and different structures. These may be combined, or a plurality of the same may be combined.

  The coupler used in the present invention can be used in the form of a solid dispersion with a water-soluble polymer using a sand mill or the like together with a basic substance and other color forming aids. Is particularly preferred. Preferred water-soluble polymers include water-soluble polymers used when preparing microcapsules (see, for example, JP-A-59-190886). In this case, the coupler, the basic substance, and the coloring aid are added to the water-soluble polymer solution in an amount of 5 to 40% by mass. The dispersed or emulsified particle size is preferably 10 μm or less.

  To the heat-sensitive recording material of the present invention, a free radical generator (compound that generates free radicals by light irradiation) used in a photopolymerizable composition or the like is added for the purpose of reducing yellowing of the background after fixing. Can do. Examples of such free radical generators include aromatic ketones, quinones, benzoin, benzoin ethers, azo compounds, organic disulfides, acyl oxime esters, and the like. The amount to be added is preferably 0.01 to 5 parts by mass of the free radical generator with respect to 1 part by mass of the diazo compound.

  Similarly, a polymerizable compound having an ethylenically unsaturated bond (hereinafter sometimes referred to as “vinyl monomer”) may be used for the purpose of reducing yellowing. The vinyl monomer is a compound having at least one ethylenically unsaturated bond (vinyl group, vinylidene group, etc.) in its chemical structure, and has a chemical form of monomer or prepolymer. Examples thereof include unsaturated carboxylic acids and salts thereof, esters of unsaturated carboxylic acids and aliphatic polyhydric alcohols, amide compounds of unsaturated carboxylic acids and aliphatic polyvalent amines, and the like.

  The vinyl monomer is preferably used at a ratio of 0.2 to 20 parts by mass with respect to 1 part by mass of the diazo compound. The free radical generator and the vinyl monomer can be used in a microcapsule together with a diazo compound. In the present invention, in addition to the above materials, citric acid, tartaric acid, oxalic acid, boric acid, phosphoric acid, pyrophosphoric acid and the like can be added as an acid stabilizer.

The heat-sensitive recording material of the present invention is prepared by preparing a coating solution containing a microcapsule containing a diazo compound, a coupler, and an organic base, and other additives, and coating a bar on a support such as paper or a synthetic resin film. It is preferable to apply and dry by a coating method such as blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating or curtain coating to provide a heat sensitive layer having a solid content of 2.5 to 30 g / m ² .

  In the heat-sensitive recording material of the present invention, microcapsules, couplers, bases, and the like may be contained in the same layer, but it is also possible to take a laminated type constitution that is contained in another layer. Further, after providing an intermediate layer as described in Japanese Patent Application No. 59-177669 on the support, a heat-sensitive layer can be applied.

<Support>
As the support used in the heat-sensitive recording material of the present invention, any paper support used for ordinary pressure-sensitive paper, heat-sensitive paper, dry or wet diazo copy paper, etc. can be used, as well as alkyl ketene dimers. Sizing with a neutral sizing agent, etc., neutral paper having a pH of 5 to 9 (as described in Japanese Patent Application No. 55-14281), Steecht sizing degree and metric square meter as described in JP-A 57-116687 A paper satisfying the relationship with the amount and having a Beck smoothness of 90 seconds or more, a paper having an optical surface roughness of 8 μm or less and a thickness of 30 to 150 μm described in JP-A-58-136492, JP Paper having a density of 0.9 g / cm ³ or less described in JP-A-58-69091 and an optical contact ratio of 15% or more, Canadian standard freeness (JIS P8121) described in JP-A-58-69097 )so Coloring with the glossy side of the base paper made by Yankee machine as described in JP-A-58-65695, which prevents the coating liquid made from pulp made by beating pulp of 400 ml (400 cc) or more. Paper with improved density and resolution. It is also possible to use paper that has been subjected to corona discharge treatment on the base paper described in Japanese Patent Application Laid-Open No. 59-35985 and whose coating suitability has been improved.

  Further, the synthetic resin film used as the support is not deformed by heating during the development process, and can be arbitrarily selected from known materials having dimensional stability. Examples of such a film include polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate film, polystyrene films, polypropylene films, polyolefin films such as polyethylene, and the like. These can be used alone or in combination. The thickness of the support is 20 to 200 μm.

<Protective layer>
In the heat-sensitive recording material of the present invention, if necessary, the heat-sensitive recording material is used for the purpose of preventing sticking or head contamination when printing on the heat-sensitive recording layer with a thermal head or imparting water resistance to the heat-sensitive recording material. On the layer, it is preferable to further provide a protective layer (hereinafter sometimes simply referred to as “protective layer”) containing polyvinyl alcohol or the like as a main component and various pigments, release agents and the like.

<Recording method>
When the recording surface of the heat-sensitive recording material of the present invention thus obtained is heated with a thermal head or the like, when the diazo compound is encapsulated in a microcapsule containing polyurea and / or polyurethane as a constituent component, the microcapsule wall Softens, and the coupler and the base compound outside the capsule enter the capsule and develop color. After recording, irradiation with light having an absorption wavelength of the diazo compound causes the diazo compound to decompose and lose reactivity with the coupler, so that the image is fixed.

  As the light source for fixing, various fluorescent lamps, xenon lamps, mercury lamps, LEDs, and the like are used. It is preferable that this emission spectrum substantially coincides with the absorption spectrum of the diazo compound used in the heat-sensitive recording material, since it can be efficiently photofixed. The heat-sensitive recording material (heat-sensitive recording material) of the present invention is exposed using a manuscript, decomposes a diazo compound other than the image forming portion to form a latent image, and then heats and develops the heat-sensitive recording material. You can also get an image.

EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to this.
<Example 1>
(Preparation of capsule liquid A)
To 19 g of ethyl acetate, 2.8 g of the diazo compound (Exemplary Compound (D-30)) described as the specific example and 10 g of tricresyl phosphate were added and mixed uniformly. Next, 7.6 g of Takenate D-110N (manufactured by Mitsui Takeda Chemical Co., Ltd.) was added to the mixed solution as a wall material and mixed uniformly to obtain a liquid I.

  The obtained liquid I was added to an aqueous phase consisting of 46.1 g of an 8% by weight aqueous solution of phthalated gelatin, 17.5 g of water and 2 g of a 10% aqueous solution of sodium dodecylbenzenesulfonate, and 40 ° C./10,000 r.p. p. The mixture was emulsified and dispersed for 10 minutes under the conditions of m. After adding 20 g of water to the obtained emulsion and homogenizing it, an encapsulation reaction was carried out at 40 ° C. for 3 hours with further stirring to obtain a capsule liquid A. The capsule particle size was 0.35 μm.

(Preparation of coupler liquid B)
Alkaline-treated ion gelatin (trade name: # 750 gelatin, Nitta Gelatin 25.5 g, 1,2-benzothiazolin-3-one (3.5% methanol solution)) 0.7286 g, calcium hydroxide 0.153 g and ion-exchanged water 143.6 g were mixed and dissolved at 50 ° C. to obtain an alkali-treated gelatin aqueous solution.

9.8 g of coupler compound (Exemplary Compound (A-9)) described in the above specific example, 9.9 g of triphenylguanidine (manufactured by Hodogaya Chemical Co., Ltd.), 4,4 ′-(m-phenylene) Isopropylidene) diphenol (trade name: bisphenol M: manufactured by Mitsui Petrochemical Co., Ltd.) 20.5 g, 3,3′-tetramethyl-5,5 ′, 6,6′-tetra (n-propoxy) -1 , 1'-spiroindane 3.2 g, 4- (2-ethylhexyloxy) benzenesulfonamide 6.7 g, calcium dodecylbenzenesulfonate (trade name: Piionin A-41-C 70% methanol solution: Takemoto Yushi Co., Ltd.) ) 4.2g was added and dissolved to obtain a liquid II.
Incidentally, shows NMR data of exemplary compound used as the coupler compound ^{(A-9) (1 H} -NMR, heavy chloroform solvent, tetramethylsilane standard, VARIAN manufactured 300MHz) are shown below.
0.9 (t, 3H), 1.2-1.5 (m, 10H), 1.8 (m, 2H), 2.1 (t, 2H), 2.5 (s, 2H), 3 .2 (t, 2H), 4.3 (t, 2H), 6.8 (d, 1H), 7.6 (d, 1H), 8.2 (s, 1H), 8.2-8. 5 (bs, 1H)

  Separately, 108.5 g of ion-exchanged water was mixed with 205.5 g of the alkali-treated gelatin solution, and the II solution was further added, followed by emulsification and dispersion at 40 ° C. and 10,000 rpm for 10 minutes using a homogenizer. The obtained emulsion was heated under reduced pressure to remove ethyl acetate, and then the concentration was adjusted so that the solid concentration was 26.5%. The particle size of the obtained coupler emulsion was 0.22 μm in median diameter as a result of particle size measurement (LA-700, measured by Horiba, Ltd.). To this, 9 g of SBR latex (trade name: SN-307, 48% by mass solution, Sumika ABS Latex Co., Ltd.) adjusted to a concentration of 26.5% by mass was added to obtain coupler liquid B. It was.

(Preparation of coating solution C)
After 6 parts of capsule liquid A, 4.4 parts of water, and 1.9 parts of a 15% by weight aqueous solution of lime-processed gelatin were uniformly mixed at 40 ° C., 8.3 parts of coupler liquid B was added and mixed uniformly. A thermal recording layer coating solution C was obtained.

(Preparation of protective layer coating solution D)
Polyvinyl alcohol (polymerization degree 1700, saponification degree 88%) 10% aqueous solution 32 parts and water 36 parts were uniformly mixed to obtain protective layer coating liquid D.

(Application)
On the support for photographic paper with polyethylene laminated on high quality paper, heat-sensitive recording layer coating solution C and protective layer coating solution D are sequentially applied with a wire bar and dried at 50 ° C. to obtain the desired diazo thermosensitive recording material. Got. The coating amount as a solid content was 6.4 g / m ² and 1.05 g / m ² , respectively.

<Evaluation>
(Raw preservation)
First, the obtained diazo thermosensitive recording sheet was stored at room temperature (about 22 ° C.) for 48 hours, and then the recording energy per unit area was 0 to 40 mJ / mm ² using a thermal head (KST type) manufactured by Kyocera Corporation. The power applied to the thermal head and the pulse width were selected so as to obtain an image by thermal printing on the diazo thermosensitive recording layer. Next, the entire surface of the diazo thermal recording layer was irradiated with an ultraviolet lamp having an emission center wavelength of 365 nm and an output of 40 W for 15 seconds to fix the image. Then, about the obtained sample, the density | concentration of the image part and the background part was measured using the Macbeth densitometer.

  Next, the diazo thermosensitive recording sheet was forcibly stored for 72 hours under the conditions of 60 ° C. and 30% relative humidity. After the image was formed and fixed in the same manner as described above, the image portion and the background portion were measured using a Macbeth densitometer. The density of the image was measured, and the difference between the density of the image area (color density) and the density of the background area (color density) before and after forced storage was compared to evaluate the raw storage stability. The results are shown in Table 1. In the evaluation of raw preservation and the following light fastness, the density of the image area is preferably higher, and the density of the background area is preferably lower.

(Light fastness)
A sample developed and fixed as described above was prepared as 32,000 Lux. Were subjected to continuous light irradiation for 240 hours using a fluorescent lamp light fastness tester, and the discoloration test of the image portion and the background portion before and after the light irradiation was performed. In the measurement, the change in density when the initial reflection density (density of the color image portion before light irradiation) with a Macbeth densitometer was about 1.1 was examined. The results are shown in Table 1.

<Example 2>
Example 1 except that coupler liquid B was obtained using the same amount of coupler compound (Exemplary Compound (A-10)) instead of the coupler compound (Exemplary Compound (A-9)) used in Example 1. Similarly, a heat-sensitive recording material was produced and evaluated in the same manner. The results are shown in Table 1.
In addition, exemplary compound (A-10) was synthesized according to the following synthesis scheme.

The synthesis scheme will be described.
202 g of the starting material 4-chloro-3-nitrobenzoic acid (1) was suspended in 500 mL of water. Thereto, 150 g of 48% aqueous NaOH was added dropwise at room temperature, and the reaction was conducted under reflux conditions for 24 hours. The resulting deep yellow reaction solution was cooled to room temperature, ice-cooled 4 mol / L aqueous HCl was added using pH test paper until the solution became acidic, and the crystallized product was collected by filtration using a Buchner funnel. The obtained slightly yellow solid was dissolved in 200 mL of ethyl acetate by heating and crystallized by adding hexane, collected by filtration, and dried in a dry box to obtain 4-hydroxy-3-nitro-benzoic acid (2). . The yield was 86%. Secondary crystals could also be obtained from the filtrate, but about 5% of raw materials were mixed.

  To 36.6 g of 4-hydroxy-3-nitro-benzoic acid (2) obtained, 31.7 g of tetrahydrogeraniol and 100 mL of toluene were added, and 0.5 mL of methanesulfonic acid was added with stirring. After confirming that the amount of dehydration was 3.5 mL with Dean Stark, the mixture was cooled to room temperature, and ethyl acetate / water was added to separate the layers. The organic layer was washed with a saturated aqueous NaCl solution, dried over magnesium sulfate, filtered, and concentrated to obtain 4-hydroxy-3-nitro-benzoic acid ester (3) in a yield of 98%.

  To 32.4 g of the obtained 4-hydroxy-3-nitro-benzoic acid ester (3), 2 g of palladium / charcoal and 100 mL of ethanol were added, followed by replacement with nitrogen gas, and then hydrogen gas was charged. The mixture was stirred at room temperature for 4 hours and then filtered through Celite to separate palladium charcoal. By concentrating the filtrate, 3-amino-4-hydroxy-benzoic acid ester (4) was obtained as a purified product in a yield of about 62%.

  To 14.5 g of the obtained 3-amino-4-hydroxy-benzoic acid ester (4), 5 g of cyanoacetic acid and 100 mL of ethyl acetate were added, and 12 g of dicyclohexylcarbodiimide was added dropwise with stirring. After stirring at room temperature for 24 hours, the resulting dicyclohexylurea was filtered off. The filtrate was concentrated, ethyl acetate / water was added, the precipitate was filtered off, and the organic layer was separated from the filtrate. The resulting organic layer was dried over magnesium sulfate, filtered, and the filtrate was concentrated to give 3- (α-cyanoacetyl) -amino-4-hydroxy-benzoic acid ester (5) as a pale yellow solid. % Yield.

To 15 g of the obtained 3- (α-cyanoacetyl) -amino-4-hydroxy-benzoic acid ester (5), 7.7 g of aminoethanethiol and 100 mL of t-butanol were added, and the mixture was stirred with heating to 70 ° C. After confirming the disappearance of the raw materials by TLC, the reaction solvent was distilled off, ethyl acetate / water was added to the residue, and the organic layer was separated. The obtained organic layer was dried over magnesium sulfate and filtered, and the filtrate was concentrated and purified by silica gel column chromatography to obtain Exemplified Compound (A-10) in a yield of 63%.
Incidentally, shows NMR data of exemplary compound used as a coupler ^{(A-10) (1 H} -NMR, heavy chloroform solvent, tetramethylsilane standard, VARIAN manufactured 300MHz) are shown below.
1.0-1.4 (m, 15H), 1.6-1.8 (m, 4H), 2.0 (t, 2H), 2.4 (s, 2H), 2.9 (t, 2H), 4.3 (t, 2H), 6.8 (d, 2H), 7.5 (d, 1H), 8.1 (s, 1H), 8.3-8.4 (bs, 1H) )

<Example 3>
Example 1 except that coupler liquid B was obtained using the same amount of coupler compound (Exemplary Compound (A-25)) instead of the coupler compound (Exemplary Compound (A-9)) used in Example 1. Similarly, a heat-sensitive recording material was produced and evaluated in the same manner. The results are shown in Table 1.
Incidentally, shows NMR data of exemplary compound used as the coupler compound ^{(A-25) (1 H} -NMR, heavy chloroform solvent, tetramethylsilane standard, VARIAN manufactured 300MHz) are shown below.
1.0-1.3 (m, 15H), 1.6-1.8 (m, 4H), 2.0 (t, 2H), 2.4 (s, 2H), 2.8 (t, 2H), 4.3 (t, 2H), 6.8 (d, 2H), 7.7 (d, 1H), 8.2 (s, 1H), 8.3-8.4 (bs, 1H) )

<Example 4>
Example 1 except that coupler liquid B was obtained using the same amount of coupler compound (Exemplary Compound (A-7)) instead of the coupler compound (Exemplary Compound (A-9)) used in Example 1. Similarly, a heat-sensitive recording material was produced and evaluated in the same manner. The results are shown in Table 1.
Incidentally, Exemplified Compound was used as the coupler compound: (A-7) NMR data indicate ⁽¹ H-NMR, heavy chloroform solvent, tetramethylsilane standard, VARIAN manufactured 300MHz) are shown below.
0.9 (t, 3H), 1.6-1.8 (m, 10H), 2.0 (t, 2H), 2.3 (s, 2H), 2.9 (t, 2H), 4 0.0 (t, 2H), 6.6 (d, 2H), 6.3 (d, 1H), 7.0 (s, 1H), 8.0 (bs, 1H)

<Comparative Example 1>
A thermosensitive recording material was prepared in the same manner as in Example 1 except that the same amount of the following coupler compound was used in place of the coupler compound (Exemplary Compound (A-9)) used in Example 1 to obtain a coupler liquid B. It produced and evaluated similarly. The results are shown in Table 1.

<Comparative example 2>
A thermosensitive recording material was prepared in the same manner as in Example 1 except that the same amount of the following coupler compound was used in place of the coupler compound (Exemplary Compound (A-9)) used in Example 1 to obtain a coupler liquid B. It produced and evaluated similarly. The results are shown in Table 1.

  From Table 1, it was found that the recording materials of Examples 1 to 4 using the anilide derivative represented by the general formula (1) as the coupler compound were excellent in hue, raw storage stability and light fastness.

Claims (8)

In a thermosensitive recording material provided with a thermosensitive recording layer containing a diazo compound and a coupler compound that reacts with the diazo compound and develops color on the support, the anilide represented by the following general formula (1) is used as the coupler compound. A heat-sensitive recording material comprising at least one of a derivative or a tautomer thereof.

(In the general formula (1), R ¹ , R ² and R ³ are each independently a hydrogen atom, halogen atom, alkyl group, aryl group, acyl group, alkoxy group, aryloxy group, alkoxycarbonyl group, carboxyl group, Represents an aminocarbonyl group, an acylamino group, an aminosulfonyl group, a sulfonamido group, a cyano group, a nitro group, an arylthio group, or an alkylthio group, wherein R ⁴ , R ⁵ , R ^6, and R ⁷ are each independently a hydrogen atom, alkyl A group, an aryl group, an alkoxycarbonyl group, or an amide group, R ⁴ and R ⁵ may be bonded to each other to form a ring, and Z is —S—, —O—, or —N (R ⁸ )-, R ⁸ represents a hydrogen atom, an alkyl group, or an aryl group, m represents 1 or 2, and n represents 1 or 2. R ¹ , R ² and R ³ in the general formula (1) are each independently a hydrogen atom, halogen atom, alkyl group, aryl group, acyl group, alkoxy group, alkoxycarbonyl group, aminocarbonyl group, acylamino group, cyano The heat-sensitive recording material according to claim 1, which represents a group, a nitro group, an arylthio group, or an alkylthio group. The heat-sensitive recording material according to claim 1 or 2, wherein the diazo compound is a diazo compound represented by the following general formula (2).

(In General Formula (2), R ¹¹ and R ¹³ each independently represents an alkyl group, an aryl group, a heterocyclic group, or an acyl group. R ¹² represents an alkyl group, an aryl group, an alkylsulfonyl group, or an arylsulfonyl group. Y ¹ represents an oxygen atom, a sulfur atom, or an amino group, Y ² represents an oxygen atom, a sulfur atom, or a single bond, Y ³ represents an oxygen atom, a sulfur atom, Or a hydrogen atom and when Y ³ is hydrogen, R ¹³ does not exist, R ¹¹ and R ¹³ may be bonded to each other to form a ring, and X ⁻ represents an anion.) The heat-sensitive recording material according to claim 3, wherein the diazo compound is a diazo compound represented by the following general formula (3).

(In the general formula (3), R ²¹ , R ²² and R ²³ each independently represents an alkyl group or an aryl group, and X ⁻ represents an anion.) The heat-sensitive recording material according to claim 3, wherein the diazo compound is a diazo compound represented by the following general formula (4).

(In the general formula (4), each R ^31, R ³² and R ³³ are independently an alkyl group or an aryl group bonded to each other with .R ³² and R ³³ may form a ring .X ^- Represents an anion.)   The heat-sensitive recording material according to any one of claims 1 to 5, wherein the diazo compound is encapsulated in a microcapsule.   The thermosensitive recording material according to claim 6, wherein the capsule wall forming the microcapsule is a capsule wall containing polyurethane and / or polyurea as a constituent component.   The thermosensitive recording material according to claim 1, further comprising a basic substance.