JPH1076757A - New thermosensitive color developing agent and thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise sensitivity and provide an excellent image retention property by a method wherein an isocyanate adduct compound having a specific melting point and a compound which develops colors by thermally reacting with the isocyanate adduct compound are blended in a heat sensitizing agent. SOLUTION: An isocyanate adduct compound having a melting point of 40 deg.C or higher and a compound which develops colors by reacting with the isocyanate compound are blended to prepare a heat sensitizing agent. As the isocyanate adduct compound, that which expressed by the formula (n represents an integer of 1-2, and an hydrogen atom of a benzene ring may be substituted by aromatic compound residue, aliphatic compound residue, and heterocyclic compound residue) is preferable. Further, a thermal recording sheet can be manufactured by providing the thermosensitive color developing layer containing the obtained heat sensitizing agent on a base material. As a concrete example of a compound which develops colors by thermal reaction with the isocyanate adduct compound, there is a leuco dye or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-sensitive agent used for a heat-sensitive recording sheet having excellent image storability, and a heat-sensitive recording sheet using the same.

[0002]

2. Description of the Related Art In recent years, for example, in various information devices such as facsimile machines, printers, recorders, etc., a thermal recording system in which recording is performed by using thermal energy has been widely used. The mainstream of these recording methods is 2
By using a recording sheet having a color-developing layer containing a component heat-sensitive agent provided on a support, and applying heat as recording energy thereto, the heat-sensitive agent components are brought into contact with each other on the recording sheet to perform color recording. is there. Among them, many use a leuco dye and an acidic substance as a heat-sensitive agent.

[0003] Recording sheets using these conventionally known leuco dyes have high whiteness, appearance and feel close to those of plain paper,
It has many excellent characteristics such as good recording aptitude such as color development sensitivity.Thermal recording has the advantages of small size, maintenance-free and no noise generation. Its applications have expanded to a wide range of fields, such as printers, computer terminals, labels, and automatic ticket vending machines such as ticketing. On the other hand, recording sheets using these leuco dyes are represented by, for example, heat-sensitive paper using crystal violet lactone and 4,4′-isopropylidenediphenol (bisphenol A) as heat-sensitive agents (see US Pat. No. 3,539,375). As described above, since the chemical resistance of the recording portion obtained by coloring is inferior, the recording easily disappears by contacting a plasticizer contained in a plastic sheet or an eraser or a chemical contained in food or cosmetics, Also, because the light resistance of the recording part is inferior,
It has the drawback of poor storage stability of the record, such as fading or even disappearing of the record by exposure to sunlight for a relatively short period of time, and this drawback imposes certain restrictions on its use. At present, improvement is strongly desired.

As such heat-sensitive recording sheets capable of obtaining recorded images having good storability in response to such demands, for example, JP-A-58-38733, JP-A-58-54085, JP-A-58-104959, JP-A-58-149388
JP-A-59-11587, JP-A-59-115
JP-A-888-88 and U.S. Pat. No. 4,521,793 disclose a recording sheet comprising a combination of a heat-sensitive agent comprising an aromatic isocyanate and a heat-sensitive agent comprising an imino compound.

Further, Japanese Patent Application Laid-Open No. 64-1580 discloses a heat-sensitive agent comprising a leuco dye and an aromatic isocyanate compound. was there. In addition, Japanese Unexamined Patent Publication No.
JP-A-48041 discloses a heat-sensitive agent comprising a leuco dye, an isocyanate compound and an amino compound. There was a problem that background covering was caused by the

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive agent comprising a specific isocyanate compound, and a heat-sensitive recording sheet using the same, which is excellent in image storability and sensitivity.

[0007]

Means for Solving the Problems The present inventors have conducted extensive studies on the synthesis of isocyanate compounds starting from general-purpose isocyanate compounds, and as a result, it has been found that certain isocyanate adduct compounds are surprisingly excellent It has been found that performance is exhibited. Furthermore, the present inventors have conducted extensive synthesis studies of isocyanate compounds starting from toluene diisocyanate compounds, which are general-purpose isocyanate compounds, and as a result, specific isocyanate compounds have surprisingly excellent performance. This led to the completion of the present invention.

That is, the present invention is as follows.
A first aspect of the present invention is a heat-sensitive agent containing an isocyanate adduct compound having a melting point of 40 ° C. or higher and a compound capable of thermally reacting with the isocyanate adduct compound to form a color.
A second aspect of the present invention is a heat-sensitive agent containing an isocyanate adduct compound represented by the following formula (a) and a compound capable of thermally reacting with the isocyanate adduct compound to form a color.

[0009]

Embedded image

(Where n represents an integer of 1 to 2. The hydrogen atom of the benzene ring may be substituted with an aromatic compound residue, an aliphatic compound residue, or a heterocyclic compound residue. Each residue may have a substituent. The same applies to the following formulas (I) to (X).) A third aspect of the present invention is represented by at least one of the following formulas (I) to (X). A heat-sensitive agent containing an isocyanate compound and a compound capable of thermally reacting with the isocyanate compound to form a color.

[0011]

Embedded image

[0012]

Embedded image

[0013]

Embedded image

(R ₁ represents an aromatic compound residue, a heterocyclic compound residue, or an aliphatic compound residue. Each residue may have a substituent. The following formula (IV):
Same in (V) and (VI). )

[0015]

Embedded image

[0016]

Embedded image

[0017]

Embedded image

[0018]

Embedded image

[0019]

Embedded image

(R ₂ represents an aromatic compound residue, a heterocyclic compound residue or an aliphatic compound residue. Each residue may have a substituent.)

[0021]

Embedded image

(R ₃ is a residue of an aromatic compound which may have a substituent, a residue of a heterocyclic compound which may have a substituent, or a residue of an aliphatic compound or an inorganic compound which may have a substituent. Represents a group.)

[0023]

Embedded image

(R ₄ and R ₅ each independently represent an aromatic compound, a heterocyclic compound or an aliphatic compound residue.
Each residue may have a substituent. R ₄ and R ₅ may form a cyclic structure with each other. A fourth aspect of the present invention is the heat-sensitive agent according to any one of the first to third aspects of the present invention, which contains a leuco dye as a compound capable of forming a color by thermally reacting with the isocyanate compound.

A fifth aspect of the present invention is the heat-sensitive agent according to any one of the first to fourth aspects of the present invention, which contains an amino compound. A sixth aspect of the present invention is the heat-sensitive agent according to the fourth aspect of the present invention, which comprises an imino compound represented by the following formula (XI) as a compound capable of thermally reacting with an isocyanate compound to form a color.

[0026]

Embedded image

(In the formula, φ represents an aromatic compound residue capable of forming a conjugated system with adjacent CＣN.) A seventh aspect of the present invention is the sixth aspect of the present invention, which contains an amino compound.
The heat-sensitive agent described in (1). An eighth aspect of the present invention is a compound capable of forming a color by a thermal reaction with an isocyanate compound, represented by the formula (X)
The first aspect of the present invention comprising the imino compound represented by I)
4. The heat-sensitive agent according to any one of 1. to 3.,

A ninth aspect of the invention is the heat-sensitive agent according to the eighth aspect of the invention, which comprises an amino compound. A tenth aspect of the invention is the heat-sensitive agent according to any one of the first to ninth aspects of the invention, which contains an acidic developer. An eleventh aspect of the invention is the heat-sensitive agent according to any one of the first to tenth aspects of the invention, which contains an organotin compound.

According to a twelfth aspect of the present invention, there is provided a heat-sensitive recording sheet having a heat-sensitive coloring layer containing the heat-sensitive agent according to any one of the first to eleventh aspects provided on a support. The isocyanate adduct compound of the present invention refers to an isocyanate having at least two or more isocyanate groups as a starting material.
An isocyanate compound having at least one isocyanate group obtained by performing an addition reaction using at least one isocyanate group of the isocyanate as a reactive group. That is, the isocyanate adduct compound of the present invention is a method in which at least one isocyanate group of the isocyanate is used as a reactive group, and the isocyanate is dimerized or trimerized via a urea bond or a biuret bond by reaction with water. Or a method of deriving to a corresponding substituted urea or substituted biuret by an addition reaction with an amine compound, or a method of dimerizing by heat or a method of deriving to a substituted urethane or a substituted allohanate by an addition reaction with an OH group-containing compound, Alternatively, it can be obtained by a method of addition reaction with a compound having active hydrogen. Further, an isocyanate adduct compound obtained by performing any of the above-mentioned reactions using an isocyanate adduct compound as a starting material, which is obtained by the above method such as carbodiimide-modified MDI or polyol-modified MDI, may be used. . The starting material isocyanate is not particularly limited as long as it has two or more isocyanate groups. For example, paraphenylene diisocyanate, 2,5-
Dimethoxybenzene-1,4-diisocyanate, 2,
4-toluene diisocyanate, 2,6-toluene diisocyanate, diphenylmethane diisocyanate, o
-Tolidine diisocyanate, 1,5-naphthylene diisocyanate, dianisidine diisocyanate, 9-ethylcarbazole-3,6-diisocyanate, 3,
3′-dimethyl-4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate 4,4 ′, 4 ″ -triisocyanatotriphenylamine, triphenylmethane triisocyanate, tris ( 4-phenylisocyanate) thiophosphate, etc. Particularly preferred examples include toluene diisocyanate.The isocyanate adduct compound of the present invention is a colorless or pale color solid at room temperature and has a melting point of The temperature may be from 40 ° C. to 500 ° C. However, depending on the structure of the compound, the compound may decompose or degrade at a temperature lower than the melting point and show no melting point. The melting point is preferably at least 50 ° C, more preferably at least 60 ° C. . The melting point of the adduct compound 4
When the temperature is lower than 0 ° C., when it is used as a heat-sensitive agent, it tends to cause problems in heat resistance and moisture resistance, and is often not preferable in practical use.

The compound capable of forming a color by thermal reaction with the isocyanate adduct compound of the present invention may be any compound capable of forming a color by reacting with the isocyanate adduct compound, but is preferably a leuco dye or an aromatic imino compound. Is used. The isocyanate adduct compound represented by the formula (a) of the present invention refers to an isocyanate represented by the formula (a), preferably toluene diisocyanate as a starting material and at least one isocyanate group of the toluene diisocyanate. An isocyanate compound having undergone an addition reaction as a reactive group and having at least one or more isocyanate groups. As the toluene diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate are generally commercially available, and can usually be obtained at low cost as a mixture of these. However, these toluene diisocyanate isomer mixtures are liquid at room temperature (100% 2,4-toluene diisocyanate, melting point 19.5 ° C. to 21.5 ° C.).
° C, 2,4-toluene dissocyanate 65% / 2,6-
3.5% melting point of a 35% mixture of toluene diisocyanate
C to 5.5 C), and it is practically difficult to use this form as a heat-sensitive agent.

That is, the isocyanate adduct compound represented by the formula (a) of the present invention, in particular, the toluene diisocyanate adduct compound is obtained by converting at least one isocyanate group of toluene diisocyanate as a reactive group. A method in which diisocyanate is dimerized or trimerized through a urea bond or biuret bond by reaction with water, a method in which a diisocyanate is converted into a corresponding substituted urea or substituted biuret by an addition reaction with an amine compound, or a method in which heat is used to dimerize the diisocyanate. It can be obtained by a method of incorporation, a method of deriving a substituted urethane or a substituted allohanate by an addition reaction with an OH group-containing compound, or a method of an addition reaction with a compound having an active hydrogen. Further, an isocyanate adduct compound obtained by performing any one of the above-mentioned reactions using the isocyanate adduct compound obtained by the above method as a starting material may be used. That is, by using this technique, it becomes possible to raise the melting point by increasing the molecular weight, to make it solid at room temperature, and to use it as a heat-sensitive agent.

Next, the isocyanate compounds (I) to (X)
Will be described in detail. The compounds (I) to (X) may have a melting point lower than 40 ° C., but the compounds (I) to (X)
By having any one of the above structures, a thermosensitive agent having practically sufficient performance can be obtained. The isocyanate compounds (I) to (X) can be obtained by reacting the corresponding amine compound with phosgene, but the method derived from isocyanates, especially toluene diisocyanate, is easier to obtain. As the toluene diisocyanate, 2,4-toluene diisocyanate and 2,6-diisocyanate are generally commercially available, and can usually be obtained at a low price as a mixture thereof. However, these toluene diisocyanate isomer mixtures are liquid at room temperature (100% 2,4-toluene diisocyanate, melting point 19.5 ° C. to 21.5 ° C., 2,4-toluene diisocyanate 65%). / 2,6-Toluene diisocyanate 35
% Mixture having a melting point of 3.5 ° C. to 5.5 ° C.), and it is practically difficult to use this form as a heat sensitive agent.

The present inventors have used one of the two isocyanate groups of isocyanates, especially toluene diisocyanate as a reactive group, and dimerized toluene diisocyanate by reaction with water via a urea bond or biuret bond. Alternatively, a specific isocyanate compound obtained by a method of trimerization, a method of derivatizing to a corresponding substituted urea or a substituted biuret by an addition reaction with an amine compound, or a method of dimerization by heat is effective. Was found. In addition, a specific isocyanate compound obtained by a method of inducing a substituted urethane or a substituted allohanate by an addition reaction with an OH group-containing compound, or a method of an addition reaction with a compound having active hydrogen, or the like, is also effective. I found it. Further, a specific isocyanate compound obtained by further performing any one of the above-mentioned reactions using the isocyanate derivative obtained by the above method as a starting material may be used. That is, by using this technique, it becomes possible to raise the melting point by increasing the molecular weight, to make it solid at room temperature, and to use it as a heat-sensitive agent.

The heat-sensitive recording sheet of the present invention in which a leuco dye is added to the isocyanate adduct compound or the isocyanate compounds (I) to (X) is, surprisingly, a conventionally well-known isocyanate compound, 4 ',
It has been found that the sensitivity is higher than when 4 ″ -triisocyanato-2,5-dimethoxytriphenylamine is used, and that the background is hardly covered by heat. Also,
Leuco dye, amine compound and isocyanate adduct compound or isocyanate compound (I) of the present invention
The heat-sensitive recording sheet composed of (X) is more surprising than the case where 4,4 ′, 4 ″ -triisocyanato-2,5-dimethoxytriphenylamine, which is a well-known isocyanate compound, is used. In particular, the plasticizer resistance and the like were very good, and there was almost no background covering due to heat or wrap.

The isocyanate used in the present invention may be any one having two or more NCO groups on the benzene ring. Examples thereof include p-phenylene diisocyanate, m-phenylene diisocyanate, toluene diisocyanate, and the like.
1,3-dimethylbenzene-4,6-diisocyanate, 1,4-dimethylbenzene-2,5-diisocyanate, 1-methoxybenzene-2,5-diisocyanate, 1-ethoxybenzene-2, 4-diisocyanate, 2,5-dimethoxybenzene-1,4-diisocyanate, 2,5-diethoxybenzene-1,4-diisocyanate, 2,5-dibutoxybenzene-1,4-di There are isocyanates and the like. Particularly preferred is toluene diisocyanate, wherein toluene diisocyanate is
Any of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate or a mixture thereof may be used. As a reactant for isocyanate and toluene diisocyanate, which are starting materials of the isocyanate adduct compound, in addition to water, for example, aniline, o-toluidine, m-toluidine, p-toluidine, o-anisidine, p-anisidine, p-phenetidine, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethyl-p-phenylenediamine, N, N-diethyl-
p-phenylenediamine, 2,4-dimethoxyaniline, 2,5-dimethoxyaniline, 3,4-dimethoxyaniline, p-aminoacetanilide, p-aminobenzoic acid, o-aminophenol, m-aminophenol,
p-aminophenol, 2,3-xylysine, 2,4-
Xylidine, 3,4-xylidine, 2,6-xylidine, acetanilide, 4-aminobenzonitrile, anthranilic acid, p-cresidine, 2,5-dichloroaniline, 2,6-dichloroaniline, 3,4-dichloroaniline, 3,5-dichloroaniline, 2,4,5-trichloroaniline, α-naphthylamine, aminoanthracene, o-ethylaniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, N-methylaniline, N- Ethyl aniline, N-propyl aniline, N-
Butylaniline, N, N-diglycidylaniline, N,
N-diglycidyl-o-toluidine, acetoacetic anilide, trimethylphenylammonium bromide, 4,4 ′
-Diamino-3,3'-diethyldiphenylmethane,
4,4′-diaminobenzanilide, 3,5-diaminochlorobenzene, diaminodiphenyl ether,
3′-dichloro-4,4′-diaminodiphenylmethane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, trizine base, o-phenylenediamine,
m-phenylenediamine, p-phenylenediamine, 2
-Chloro-p-phenylenediamine, dianisidine, p
-Methyl aminobenzoate, ethyl p-aminobenzoate,
n-propyl p-aminobenzoate, -iso-propyl p-aminobenzoate, butyl p-aminobenzoate, p
-Dodecyl aminobenzoate, benzyl p-aminobenzoate, o-aminobenzophenone, m-aminoacetophenone, p-aminoacetophenone, m-aminobenzamide, o-aminobenzamide, p-aminobenzamide, p-amino-N-methyl Benzamide, 3-amino-4-methylbenzamide, 3-amino-4-methoxybenzamide, 3-amino-4-chlorobenzamide,
p- (N-phenylcarbamoyl) aniline, p- [N
-(4-chlorophenyl) carbamoyl] aniline, p
-[N- (4-aminophenyl) carbamoyl] aniline, 2-methoxy-5- (N-phenylcarbamoyl)
Aniline, 2-methoxy-5- [N- (2'-methyl-
3'-chlorophenyl) carbamoyl] aniline, 2-
Methoxy-5- [N- (2'-chlorophenyl) carbamoyl] aniline, 5-acetylamino-2-methoxyaniline, 4-acetylaminoaniline, 4- (N-methyl-N-acetylamino) aniline, 2,5 -Diethoxy-4- (N-benzoylamino) aniline, 2,5
-Dimethoxy-4- (N-benzoylamino) aniline, 2-methoxy-4- (N-benzoylamino) -5
-Methylaniline, 4-sulfamoylaniline, 3-
Sulfamoylaniline, 2- (N-ethyl-N-phenylaminosulfonyl) aniline, 4-dimethylaminosulfonylaniline, 4-diethylaminosulfonylaniline, sulfathiazole, 4-aminodiphenylsulfone, 2-chloro-5-N -Phenylsulfamoylaniline, 2-methoxy-5-N, N-diethylsulfamoylaniline, 2,5-dimethoxy-4-N-phenylsulfamoylaniline, 2-methoxy-5-benzylsulfonylaniline, 2 -Phenoxysulfonylaniline, 2- (2'-chlorophenoxy) sulfonylaniline, 3-anilinosulfonyl-4-methylaniline, bis [4- (m-aminophenoxy) phenyl] sulfone, bis [4- (p-amino Phenoxy) phenyl] sulfone, bis [ -Methyl-4- (p-aminophenoxy) phenyl] sulfone, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'- Dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, ortho-tolidine sulfone, 2,
4'-diaminobiphenyl, 2,2'-diaminobiphenyl, 4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diamino Biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-thiodianiline, 2,2'dithiodianiline, 4,4'-dithiodianiline, 4,4'-diaminodiphenyl ether, , 3'-Diaminodiphenyl ether, 3,4 '
-Diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, bis (3-amino-4-chlorophenyl) sulfone, bis (3,4-diaminophenyl) sulfone, bis (4-aminophenyl) Sulfone, bis (3-aminophenyl) sulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 4,4-
Diaminodiphenylamine, 4,4'-ethylenedianiline, 4,4'diamino-2,2'-dimethyldibenzyl, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 1,4-bis (4 -Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy)
Benzene, 9,9-bis (4-aminophenyl) fluorene, 2,2-bis (4-aminophenoxyphenyl)
Propane, 4,4'-bis (4-aminophenoxy) diphenyl, 3,3 ', 4,4'-tetraaminodiphenyl ether, 3,3', 4,4'-tetraaminodiphenylsulfone, 3,3'4 , 4'-Tetraaminobenzophenone, 3-aminobenzonitrile, 4-phenoxyaniline, 3-phenoxyaniline, 4,4'-methylenebis-O-toluidine, 4,4 '-(p-phenyleneisopropylidene) -bis- (2,6-xylidine),
o-chloro-p-nitroaniline, o-nitro-p-chloroaniline, 2,6-dichloro-4-nitroaniline, 5-chloro-2-nitroaniline, 2-amino-4
-Chlorophenol, o-nitroaniline, m-nitroaniline, p-nitroaniline, 2-methyl-4-nitroaniline, m-nitro-p-toluidine, 2-amino-5-nitrobenzonitrile, methol, 2,4 -Diaminophenol, p-hydroxyphenylglycine, N
-(Β-hydroxyethyl) -o-aminophenol sulfate, sulfanilic acid, metanylic acid, 4B acid, C acid,
B acid, p-fluoroaniline, o-fluoroaniline,
3-chloro-4-fluoroaniline, 2,4-difluoroaniline, 2,3,4-trifluoroaniline, m-
Aminobenzotrifluoride, m-toluylenediamine, 2-aminothiophenol, 2-amino-3-bromo-5-nitrobenzonitrile, diphenylamine, p
-Aminodiphenylamine, octylated diphenylamine, 2-methyl-4-methoxydiphenylamine, N,
N-diphenyl-p-phenylenediamine, dianisidine, 3,3′-dichlorobenzidine, 4,4′-diaminostilbene-2,2′-disulfonic acid, benzylethylaniline, 1,8-naphthalenediamine, sodium naphthionate, Tobias acid, H acid, J acid, Phenyl J acid,
Aromatic amines such as 1,4-diamino-anthraquinone and 1,4-diamino-2,3-dichloroanthraquinone, and 3-amino-1,2,4-triazole,
-Aminopyridine, 3-aminopyridine, 4-aminopyridine, α-amino-ε-caprolactam, acetoguanamine, 2,4-diamino-6- [2′-methylimidazolyl- (1)] ethyl-S-triazine, 2,3-diaminopyridine, 2,5-diaminopyridine, 2,3
Heterocyclic compounds such as 5-triaminopyridine, 1-amino-4-methylpiperazine, 1- (2-aminoethyl) piperazine, bis (aminopropyl) piperazine, N- (3-aminopropyl) morpholine, amines, methyl Amine, ethylamine, dimethylamine, diethylamine, stearylamine, allylamine, diallylamine, isopropylamine, diisopropylamine, 2-
Ethylhexylamine, ethanolamine, 3- (2-
Ethylhexyloxy) propylamine, 3-ethoxypropylamine, diisobutylamine, 3- (diethylamino) propylamine, di-2-ethylhexylamine, 3- (dibutylamino) propylamine, t-butylamine, propylamine, 3- (methyl Amino) propylamine, 3- (dimethylamino) propylamine,
3-methoxypropylamine, methylhydrazine, 1-
Methylbutylamine, methanediamine, 1,4-diaminobutane, cyclohexanemethylamine, cyclohexylamine, 4-methylcyclohexylamine, 2-bromoethylamine, 2-methoxyethylamine, 2-ethoxymethylamine, 2-amino-1-propanol, 2
-Aminobutanol, 3-amino-1,2-propanediol, 1,3-diamino-2-hydroxypropane,
Aliphatic amines such as 2-aminoethanethiol, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (2,2, 6,6-tetramethyl-4-
Piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid
1,2,2,6,6-pentamethyl-4-piperidinol β, β, β ′, β′-tetramethyl-3,9-
(2,4,8,10-tetraoxaspiro [5,5] undecanediethanol condensate, 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4
-Piperidinol / β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecanediethanol condensate, poly [｛6
-(1,1,3,3-tetramethylbutyl) amino-
1,3,5-triazine-2,4-diyl {(2,
2,6,6-tetramethyl-4-piperidyl) imino}
Hexamethylene ｛(2,2,6,6-tetramethyl-4
-Piperidyl) imino}], N, N'-bis (3-aminopropyl) ethylenediamine 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-
Piperidyl) amino] -6-chloro-1,3,5-triazine condensate, 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid-bis (1, Hindered amine compounds such as 2,2,6,6-pentamethyl-4-piperidyl) and succinic acid-bis (2,2,6,6-tetramethyl-4-piperidienyl) ester.

Further, examples of the OH group-containing compound include:
Phenol, cresol, xylenol, p-ethylphenol, o-isopropylphenol, resorcinol,
p-tert-butylphenol, p-tert-octylphenol, 2-cyclohexylphenol, 2-
Allylphenol, 4-indanol, thymol, 2-
Naphthol, p-nitrophenol, o-chlorophenol, p-chlorophenol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (hydroxyphenyl) butane, 2,2-bis (hydroxyphenyl) Pentane, 2,2-bis (hydroxyphenyl) heptane, catechol, 3-methylcatechol, 3-methoxycatechol, pyrogallol, hydroquinone, methylhydroquinone, 4-phenylphenol, p, p '
Phenols such as -biphenol and 4-cumylphenol (however, those phenols having an amino group are not preferred. When an amino group is present, the reactivity with an isocyanate group is higher than that of an OH group; The amino group reacts first and the desired compound cannot be obtained.) Methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, isopropanol, 2-pentanol, 3
-Hexanol, tert-butanol, tert-amyl alcohol, methyl cellosolve, butyl cellosolve, methyl carbitol, allyl alcohol, 2-methyl-2-propen-1-ol, benzyl alcohol,
Alcohols such as 4-pyridinemethanol, phenylcellosolve, furfuryl alcohol, cyclohexanol, cyclohexylmethanol, cyclopentanol, 2-chloroethanol, 1-chloro-3-hydroxypropane, glycerin, glycerol, polypropylene glycol, polytetramethylene Ether glycol, adipate polyol, epoxy modified polyol, polyether ester polyol polycarbonate polyol, polycaprolactone diol, phenol polyol, polyether polyols such as amine modified polyol, ethylene glycol, diethylene glycol,
1,3-propanediol, 1,2-propanediol, propylene glycol, dipropylene glycol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, 1,6-hexaneglycol, 1,9-nonanediol, acrylic polyol, fluorine polyol, polybutadiene polyol, polyhydroxy polyol, trimethylolpropane, trimethylolethane, hexanetriol, phosphoric acid, neopentyl Active hydrogen that reacts with glycols, pentaerythritol, castor oil-based polyols, polymer polyols, methylpentanediol, halogen-containing polyols, phosphorus-containing polyols, ethylenediamine, α-methylglucoside, sorbitol, and souces, and other polyols such as isocyanates Compounds having dimethyl malonate, diethyl malonate, ethyl acetoacetate, butyl mercaptan, thiophenol, tert-dodecyl mercaptan, acetoacetate Nishijido, acetamide, benzamide, p- toluenesulfonamide, o- toluenesulfonamide, p- chlorobenzene sulfonamide, benzene sulfonamide, hydrazine, hydroxylamine,
Succinimide, maleic imide, acetanilide,
Imidazole, methyl ethyl ketoxime, acetoaldoxime, sodium bisulfite, urea, ammonia, 3-
Examples include imino compounds such as iminoisoindoline and iminobenzophenone, and imine compounds such as piperidine, ethyleneimine and piperazine.

In order to obtain the isocyanate adduct compound used in the present invention, the reactant is mixed with the isocyanate in an organic solvent or in the absence of a solvent and reacted, and excess isocyanate is removed by filtration or distillation under reduced pressure. The desired product can be obtained. A single or a plurality of reactants may be used depending on the purpose. The solvent may be any solvent that does not cause a reaction with the isocyanate group and the functional group of the reactant,
Examples include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, chlorinated aromatic hydrocarbons, chlorinated alicyclic hydrocarbons, and the like. In particular, cyclohexane, ethylcyclohexane, toluene, and the like which dissolve the isocyanate and have low solubility of the product are preferable. The product obtained by the above reaction operation is not necessarily a single product, but a mixture of a compound having different substituent positions, a mixture of a substituted urea and a substituted biuret, a mixture of a substituted urethane and a substituted allohanate, and further an addition reaction proceeds. It may be obtained as a mixture of those having a molecular weight, but this is also acceptable. The target product can also be obtained by reacting the reaction agent with the product obtained by the above reaction operation as a starting material. The melting point of the isocyanate adduct compound thus obtained is 500 ° C. at 40 ° C. or higher.
The following is acceptable. However, depending on the structure of the compound, it may be decomposed or deteriorated at a temperature lower than the melting point and show no melting point, but in this case there is no problem in performance at 40 ° C. or more. It is preferably at least 50 ° C, more preferably at least 60 ° C. Adduct compound has a melting point of 40 ° C
If it is less than 7, when it is used as a heat-sensitive agent, it tends to cause problems in heat resistance and moisture resistance, and is often not preferable in practical use.

In order to obtain the isocyanate compounds (I) to (X) of the present invention, the reactant is mixed with an isocyanate, in particular, toluene diisocyanate in an organic solvent or without a solvent, and then reacts with excess. The target product can be obtained by removing the toluene diisocyanate by filtration or distillation under reduced pressure. A single or a plurality of reactants may be used depending on the purpose. The solvent may be any solvent that does not cause a reaction with the isocyanate group and the functional group of the reactant, for example, an aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon,
Chlorinated aliphatic hydrocarbons, chlorinated aromatic hydrocarbons, chlorinated alicyclic hydrocarbons and the like can be mentioned. In particular, cyclohexane, ethylcyclohexane, toluene, and the like, which dissolve toluene diisocyanate and have low solubility of the product, are preferable. The product obtained by the above reaction operation is not necessarily a single product, but a mixture of a compound having different substituent positions, a mixture of a substituted urea and a substituted biuret, a mixture of a substituted urethane and a substituted allohanate, and further an addition reaction proceeds. It may be obtained as a mixture of those having a molecular weight, but this is also acceptable. The target product can also be obtained by reacting the reaction agent with the product obtained by the above reaction operation as a starting material. Further, the isocyanate adduct compound of the present invention or the isocyanate compounds (I) to (X) may be a phenol, a lactam,
It may be used in the form of a so-called block isocyanate which is an addition compound with oximes and the like. The isocyanate adduct compound of the present invention and the isocyanate compounds (I) to (X) are colorless or light-colored solids at ordinary temperature. In preparing the heat-sensitive recording sheet, one type of the isocyanate adduct compound or the isocyanate compounds (I) to (X) may be used, or two or more types may be used in combination, if necessary.

The leuco dye, which is an example of the isocyanate adduct compound of the present invention and a compound capable of forming a color by a thermal reaction with the isocyanate compounds (I) to (X), is used as a heat-sensitive agent already used in a heat-sensitive recording sheet. It is a known compound and is not particularly limited, and examples thereof include the following. (1) Triarylmethane compound 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- ( p-dimethylaminophenyl) -3-
(1,2-dimethylindol-3-yl) phthalide,
3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-phenylindole-
3-yl) phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindole-3-
Yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -5-dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -5 -Dimethylaminophthalide, 3-
p-dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide and the like.

(2) Diphenylmethane compounds 4,4-bis-dimethylaminophenylbenzhydryl benzyl ether, N-halophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine and the like. (3) Xanthene compounds rhodamine B anilinolactam, rhodamine Bp-chloroanilinolactam, 3-diethylamino-7-dibenzylaminofluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7 -Phenylfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-7- (3,4-dichloroanilino) fluoran, 3-diethylamino- 7
-(2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- (N
-Ethyl-N-tolyl) amino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-tolyl) amino-6 Methyl-7-phenethylfluoran, 3-diethylamino-7- (4-nitroanilino) fluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3- (N-methyl-N-propyl) amino-
6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-methyl-N-cyclohexyl) amino-6 Methyl-7-anilinofluoran, 3
-(N-ethyl-N-tetrahydrofuryl) amino-6
-Methyl-7-anilinofluoran and the like.

(4) Thiazine compounds Benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue and the like. (5) Spiro compound 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (3-methoxybenzo) Spiropyran, 3-propylspirobenzopyran and the like.

The amino compound used in the present invention is a colorless or pale substance having at least one primary, secondary or tertiary amino group. Specific examples of these amino compounds include beef tallow or coconut oil-derived aliphatic amines, cetylamine, stearylamine, p-
Methyl aminobenzoate, ethyl p-aminobenzoate, p
-N-propyl aminobenzoate, -iso-propyl p-aminobenzoate, butyl p-aminobenzoate, p-
Dodecyl aminobenzoate, benzyl p-aminobenzoate, o-aminobenzophenone, m-aminoacetophenone, p-aminoacetophenone, m-aminobenzamide, o-aminobenzamide, p-aminobenzamide, p-amino-N-methylbenzamide 3-amino-4-methylbenzamide, 3-amino-4-methoxybenzamide, 3-amino-4-chlorobenzamide,
p- (N-phenylcarbamoyl) aniline, p- [N
-(4-chlorophenyl) carbamoyl] aniline, p
-[N- (4-aminophenyl) carbamoyl] aniline, 2-methoxy-5- (N-phenylcarbamoyl)
Aniline, 2-methoxy-5- [N- (2'-methyl-
3'-chlorophenyl) carbamoyl] aniline, 2-
Methoxy-5- [N- (2'-chlorophenyl) carbamoyl] aniline, 5-acetylamino-2-methoxyaniline, 4-acetylaminoaniline, 4- (N-methyl-N-acetylamino) aniline, 2,5 -Diethoxy-4- (N-benzoylamino) aniline, 2,5
-Dimethoxy-4- (N-benzoylamino) aniline, 2-methoxy-4- (N-benzoylamino) -5
-Methylaniline, 4-sulfamoylaniline, 3-
Sulfamoylaniline, 2- (N-ethyl-N-phenylaminosulfonyl) aniline, 4-dimethylaminosulfonylaniline, 4-diethylaminosulfonylaniline, sulfathiazole, 4-aminodiphenylsulfone, 2-chloro-5-N -Phenylsulfamoylaniline, 2-methoxy-5-N, N-diethylsulfamoylaniline, 2,5-dimethoxy-4-N-phenylsulfamoylaniline, 2-methoxy-5-benzylsulfonylaniline, 2 -Phenoxysulfonylaniline, 2- (2'-chlorophenoxy) sulfonylaniline, 3-anilinosulfonyl-4-methylaniline, bis [4- (m-aminophenoxy) phenyl] sulfone, bis [4- (p-amino Phenoxy) phenyl] sulfone, bis [ -Methyl-4- (p-aminophenoxy) phenyl] sulfone, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'- Dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, ortho-tolidine sulfone, 2,
4'-diaminobiphenyl, 2,2'-diaminobiphenyl, 4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diamino Biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-thiodianiline, 2,2'-dithiodianiline, 4,4'-
Dithiodianiline, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,
4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, bis (3-amino-4-chlorophenyl) sulfone, bis (3,4-diaminophenyl) sulfone, bis (4-amino Phenyl) sulfone, bis (3-aminophenyl) sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenylmethane, 4,4 '
-Ethylenedianiline, 4,4'diamino-2,2'-
Dimethyldibenzyl, 4,4'-diamino-3,3'-
Dichlorodiphenylmethane, 3,3'-diaminobenzophenone, 4,4'-diaminobenzophenone, 1,4
-Bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 9,9-bis (4
-Aminophenyl) fluorene, 2,2-bis (4-aminophenoxyphenyl) propane, 4,4'-bis (4-aminophenoxy) diphenyl, 3,3 ', 4,
4'-tetraaminodiphenyl ether, 3,3 ',
4,4'-tetraaminodiphenyl sulfone, 3,3 '
4,4'-tetraaminobenzophenone, 4-aminobenzonitrile, 3-aminobenzonitrile, p-phenylenediamine, m-phenylenediamine, 4-phenoxyaniline, 3-phenoxyaniline, 4,4'-diaminodiphenylmethane, , 4'-Methylenebis-O-
Aniline derivatives such as toluidine, 4,4 '-(p-phenyleneisopropylidene) -bis- (2,6-xylysine), and acetoguanamine, 2,4-diamino-
6- [2'-methylimidazolyl- (1)] ethyl-S
-Triazine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2,3-diaminopyridine,
Heterocyclic compounds such as 2,5-diaminopyridine and 2,3,5-triaminopyridine, and tetrakis (1,
2,2,6,6-pentamethyl-4-piperidyl)-
1,2,3,4-butanetetracarboxylate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, 1,2,3 4-butanetetracarboxylic acid ・ 1,
2,2,6,6-pentamethyl-4-piperidinol
β, β, β ′, β′-tetramethyl-3,9- (2,
4,8,10-tetraoxaspiro [5,5] undecanediethanol condensate, 1,2,3,4-butanetetracarboxylic acid · 2,2,6,6-tetramethyl-4-piperidinol · β, β , Β ', β'-tetramethyl-3,
9- (2,4,8,10-tetraoxaspiro [5,
5] undecanediethanol condensate, poly [$ 6-
(1,1,3,3-tetramethylbutyl) amino-1,
3,5-triazine-2,4-diyl {(2,2,
6,6-tetramethyl-4-piperidyl) imino {hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], N, N'-bis (3-aminopropyl) ethylenediamine. 2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, 2- (3 Bis- (1,5-Di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonic acid
Hindered amine compounds such as 2,2,6,6-pentamethyl-4-piperidyl) and succinic acid-bis (2,2,6,6-tetramethyl-4-piperidienyl) ester are exemplified.

Further, among the above-mentioned amino compounds, an aniline derivative having at least one amino group represented by the following formula (XII) is particularly preferable.

[0044]

Embedded image

(Wherein R ₆ , R ₇ , R ₈ and R ₉ are
Each independently represents hydrogen, halogen, an alkyl group, an alkoxy group or an amino group; X ₂ and X ₃ represent an amino group or a formula (b);

[0046]

Embedded image

Y ₁ is —SO ₂ —, —O—, — (S)
_{n -, - (CH 2)} n -, - CO -, - CONH-, or of formula (c),

[0048]

Embedded image

Or, the case where it does not exist is shown. n is 1 or 2. The amino compound may be used alone or as a mixture. In order to improve the print preservability in plasticizer resistance, 1 to 500% by weight based on the isocyanate compound is used.
It is preferred that If the content of the amino compound is less than 1% by weight based on the isocyanate compound, sufficient print storability cannot be obtained. Further, even if it is used in an amount exceeding 500% by weight, the performance is not improved, and the cost is disadvantageous.

The isocyanate adduct compound of the present invention and an imino compound which is another example of a compound capable of forming a color upon thermal reaction with a specific isocyanate compound are at least one compound represented by the following formula (XIII). A compound having an imino group represented by the following general formula (XI), and is a colorless or pale-colored solid at room temperature.
Two or more imino compounds can be used in combination depending on the purpose. Specific examples are shown below.

[0051]

Embedded image

[0052]

Embedded image

(In the formula, φ represents an aromatic compound residue capable of forming a conjugated system with an adjacent CＮN.) 3-iminoisoindoline-1-one, 3-imino-
4,5,6,7-tetrachloroisoindoline-1-one, 3-imino-4,5,6,7-tetrabromoisoindoline-1-one, 3-imino-4,5,6,7- Tetrafluoroisoindoline-1-one, 3-imino-
5,6-dichloroisoindoline-1-one, 3-imino-4,5,7-trichloro-6-methoxy-isoindoline-1-one, 3-imino-4,5,7-trichloro-6-methyl Mercapto-isoindoline-1-one, 3-imino-6-nitroisoindoline-1-one, 3-imino-isoindoline-1-spiro-dioxolan, 1,1-dimethoxy-3-imino-isoindoline, , 1-diethoxy-3-imino-4,5,6
7-tetrachloroisoindoline, 1-ethoxy-3-
Imino-isoindoline, 1,3-diiminoisoindoline, 1,3-diimino-4,5,6,7-tetrachloroisoindoline, 1,3-diimino-6-methoxyisoindoline, 1,3-diimino -6-cyanoisoindoline, 1,3-diimino-4,7-dithia-5,5,
6,6-tetrahydroisoindoline, 7-amino-
2,3-dimethyl-5-oxopyrrolo [3,4b] pyrazine, 7-amino-2,3-diphenyl-5-oxopyrrolo [3,4b] pyrazine, 1-iminonaphthalimide, 1-iminodiphenimide, 1- Phenylimino-3-iminoisoindoline, 1- (3'-chlorophenylimino) -3-iminoisoindoline, 1-
(2 ', 5'-dichlorophenylimino) -3-iminoisoindoline, 1- (2', 4 ', 5'-trichlorophenylimino) -3-iminoisoindoline, 1-
(2'-cyano-4'-nitrophenylimino) -3-
Iminoisoindoline, 1- (2'-chloro-5'-cyanophenylimino) -3-iminoisoindoline, 1
-(2 ', 6'-dichloro-4'-nitrophenylimino) -3-iminoisoindoline, 1- (2', 5'-
Dimethoxyphenylimino) -3-iminoisoindoline, 1- (2 ', 5'-diethoxyphenylimino)-
3-iminoisoindoline, 1- (2'-methyl-4 '
-Nitrophenylimino) -3-iminoisoindoline, 1- (5'-chloro-2'-phenoxyphenylimino) -3-iminoisoindoline, 1- (4'-
N, N-dimethylaminophenylimino) -3-iminoisoindoline, 1- (3'-N, N-dimethylamino-4'-methoxyphenylimino) -3-iminoisoindoline, 1- (2'-methoxy) -5'-N-phenylcarbamoylphenylimino) -3-iminoisoindoline, 1- (2'-chloro-5'-trifluoromethylphenylimino) -3-iminoisoindoline, 1-
(5 ', 6'-dichlorobenzothiazolyl-2'-imino) -3-iminoisoindoline, 1- (6'-methylbenzothiazolyl-2'-imino) -3-iminoisoindoline, 1 -(4'-phenylaminophenylimino) -3-iminoisoindoline, 1- (p-phenylazophenylimino) -3-iminoisoindoline, 1
-(Naphthyl-1'-imino) -3-iminoisoindoline, 1- (anthraquinone-1'-imino) -3-iminoisoindoline, 1- (5'-chloroanthraquinone-1'-imino)- 3-iminoisoindoline, 1-
(N-ethylcarbazolyl-3′-imino) -3-iminoisoindoline, 1- (naphthoquinone-1′-imino) -3-iminoisoindoline, 1- (pyridyl-
4'-imino) -3-iminoisoindoline, 1- (benzimidazolone-6'-imino) -3-iminoisoindoline, 1- (1'-methylbenzimidazolone-6 '
-Imino) -3-iminoisoindoline, 1- (7'-
Chlorobenzimidazolone-5'-imino) -3-iminoisoindoline, 1- (benzimidazolyl-2'-
Imino) -3-iminoisoindoline, 1- (benzimidazolyl-2'-imino) -3-imino-4,5,
6,7-tetrachloroisoindoline, 1- (2 ',
4'-dinitrophenylhydrazone) -3-iminoisoindoline, 1- (indazolyl-3'-imino) -3
-Iminoisoindoline, 1- (indazolyl-3'-
Imino) -3-imino-4,5,6,7-tetrabromoisoindoline, 1- (indazolyl-3'-imino)
-3-imino-4,5,6,7-tetrafluoroisoindoline, 1- (benzimidazolyl-2'-imino)
-3-imino-4,7-dithiatetrahydroisoindoline, 1- (4 ', 5'-dicyanoimidazolyl-2'
-Imino) -3-imino-5,6-dimethyl-4,7-
Pyradiisoindolin, 1- (cyanobenzoylmethylene) -3-iminoisoindoline, 1- (cyanocarbonamidomethylene) -3-iminoisoindoline, 1-
(Cyanocarbomethoxymethylene) -3-iminoisoindoline, 1- (cyanocarboethoxymethylene) -3
-Iminoisoindoline, 1- (cyano-N-phenylcarbamoylmethylene) -3-iminoisoindoline,
1- [cyano-N- (3'-methylphenyl) -carbamoylmethylene] -3-iminoisoindoline, 1-
[Cyano-N- (4'-chlorophenyl) -carbamoylmethylene] -3-iminoisoindoline, 1- [cyano-N- (4'-methoxyphenyl) -carbamoylmethylene] -3-iminoisoindoline, 1- [ Cyano
N- (3'-chloro-4'-methylphenyl) -carbamoylmethylene] -3-iminoisoindoline, 1-
(Cyano-p-nitrophenylmethylene) -3-iminoisoindoline, 1- (dicyanomethylene) -3-iminoisoindoline, 1- [cyano-1 ′, 2 ′, 4′-
Triazolyl- (3 ')-carbamoylmethylene] -3
-Iminoisoindoline, 1- [cyanothiazoyl-
(2 ′)-carbamoylmethylene] -3-iminoisoindoline, 1- [cyanobenzimidazolyl- (2 ′)
-Carbamoylmethylene] -3-iminoisoindoline, 1- [cyanobenzothiazolyl- (2 ')-carbamoylmethylene] -3-iminoisoindoline, 1-
[Cyanobenzimidazolyl- (2 ')-methylene]-
3-iminoisoindoline, 1- [cyanobenzimidazolyl- (2 ')-methylene] -3-imino-4,5,
6,7-tetrachloroisoindoline, 1-[(cyanobenzimidazolyl-2 ')-methylene] -3-imino-5-methoxyisoindoline, 1-[(cyanobenzimidazolyl-2')-methylene] -3 -Imino-6-
Chloroisoindoline, 1-[(1′-phenyl-3 ′
-Methyl-5-oxo) -pyrazolidene-4 ']-3-
Iminoisoindoline, 1-[(cyanobenzimidazolyl-2 ')-methylene] -3-imino-4,7-dithiatetrahydroisoindoline, 1-[(cyanobenzimidazolyl-2')-methylene] -3- Imino-5
6-dimethyl-4,7-pyradiisoindoline, 1-
[(1'-methyl-3'-n-butyl) -barbituric acid-5 ']-3-iminoisoindoline, 3-imino-1
-Sulfobenzoimide, 3-imino-1-sulfo-6
-Chlorobenzoic imide, 3-imino-1-sulfo-
5,6-dichlorobenzoic imide, 3-imino-1-sulfo-4,5,6,7-tetrachlorobenzoic imide,
3-imino-1-sulfo-4,5,6,7-tetrabromobenzoic imide, 3-imino-1-sulfo-4,5,
6,7-tetrafluorobenzoic imide, 3-imino-
1-sulfo-6-nitrobenzoic acid imide, 3-imino-
1-sulfo-6-methoxybenzoic imide, 3-imino-1-sulfo-4,5,7-trichloro-6-methylmercaptobenzoic imide, 3-imino-1-sulfonaphthoic imide, 3-imino-1 -Sulfo-5-bromonaphthoic imide, 3-imino-2-methyl-4,5,
6,7-tetrachloroisoindoline-1-one and the like.

Of these, iminoisoindoline derivatives are particularly preferred, and 1,3-diimino-4,
5,6,7-tetrachloroisoindoline, 3-imino-4,5,6,7-tetrachloroisoindoline-1-
On, 1,3-diimino-4,5,6,7-tetrabromoisoindoline is preferred. The present invention has a melting point of 40 ° C.
The above isocyanate adduct compound or the isocyanate adduct compound represented by the formula (a) or the isocyanate compound represented by at least one of the formulas (I) to (X), and these isocyanate compounds It is a heat-sensitive agent containing a compound capable of forming a color by a thermal reaction. A leuco dye is one example of a compound capable of forming a color by a thermal reaction with the isocyanate compound. The heat-sensitive recording sheet of the present invention obtained by adding a leuco dye to the isocyanate adduct compound or the isocyanate compounds (I) to (X) has a clear color and excellent sensitivity. Compound 4,
It has been found that the sensitivity is higher than when 4 ', 4''-triisocyanato-2,5-dimethoxytriphenylamine is used, and the background is hardly covered by heat.

Further, the heat-sensitive agent of the present invention in which an amine compound is further added to the heat-sensitive agent comprising these isocyanate compound and leuco dye, produces a vivid color and further excellent sensitivity, and surprisingly, isocyanate conventionally well known. Compared to the case of using 4,4 ', 4''-triisocyanato-2,5-dimethoxytriphenylamine, which is a naat compound, the plasticizer resistance and the like are very good, and the background is hardly covered by heat or wrap. Did not occur.

In the present invention, an imino compound is another example of a compound capable of thermally developing with these isocyanate compounds to form a color. The isocyanate compound of the present invention can be obtained at very low cost, and when combined with an imino compound, a clear light-colored hue can be obtained, and a heat-sensitive recording sheet excellent in print preservability without covering the background can be obtained. In addition, a heat-sensitive recording material in which an amino compound is combined with the heat-sensitive adhesive can provide a heat-sensitive recording sheet with less background covering.

The sensitivity is increased by adding an acidic developer to the heat-sensitive agent comprising the isocyanate adduct compound of the present invention or the isocyanate compound represented by at least one of formulas (I) to (X) and a leuco dye. An improved and vivid color-developed thermosensitive recording sheet can be obtained. As the acidic developer, generally used electron-accepting substances are used. In particular, phenol derivatives, aromatic carboxylic acid derivatives or metal compounds thereof, salicylic acid derivatives or metal salts thereof, N, N-diarylthiourea derivatives, sulfonylurea derivatives, etc. Is preferred. Particularly preferred are phenol derivatives, specifically, 2,2-bis (4-
(Hydroxyphenyl) propane, 2,2-bis (hydroxyphenyl) butane, 2,2-bis (hydroxyphenyl) pentane, 2,2-bis (hydroxyphenyl)
Heptane, 1,1-bis (4-hydroxyphenyl) cyclohexane, butyl bis (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate,
Bis (4-hydroxyphenyl) sulfone, bis (3-
Methyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-4′-methylphenylsulfone, 3-
Chloro-4-hydroxyphenyl-4'-methylphenylsulfone, 3,4-dihydroxyphenyl-4'-methylphenylsulfone, 4-isopropylphenyl-
4′-hydroxyphenylsulfone, 4-isopropyloxyphenyl-4′-hydroxyphenylsulfone,
Bis (2-allyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-4'-benzyloxyphenylsulfone, 4-isopropylphenyl-4'-hydroxyphenylsulfone, bis (2-methyl-3-t
ert. -Butyl-4-hydroxyphenyl) sulfide, methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 4-hydroxybenzoic acid (4'-chlorobenzyl), 1,2-bis (4'-hydroxybenzoic acid) Ethyl, pentyl 1,5-bis (4'-hydroxybenzoate), hexyl 1,6-bis (4'-hydroxybenzoate), dimethyl 3-hydroxyphthalate, stearyl gallate, lauryl gallate and the like. Can be. Examples of the salicylic acid derivative include 3-n-octyloxysalicylic acid, 3-n-butyloxysalicylic acid, 3-n-pentyloxysalicylic acid, 3-n-dodecyloxysalicylic acid, and 3-n-octoctanoyloxysalicylic acid. -Octylaminosalicylic acid, 3
-N-octanoylaminosalicylic acid and the like.
Examples of the sulfonylurea derivative include 4,4-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and 4,4-bis (o-toluenesulfonylaminocarbonylamino) diphenylmethane 4,4-bis (p-toluenesulfonylaminocarbonylamino) diphenyl Compounds containing one or more arylsulfonylaminoureido groups such as sulfide, 4,4-bis (p-toluenesulfonylaminocarbonylamino) diphenyl ether, N- (p-toluenesulfonyl) -N'-phenylurea are exemplified.

Addition of the organotin compound used in the present invention further reduces background fogging. The organic tin compound is a compound having tetravalent tin in a molecule and having at least one alkyl group. As a property, it is a solid or liquid colorless or pale compound at normal temperature,
Odorless or low-odor compounds, for example, di-n-
Octyltin bis (isooctylthioglycolic acid alkyl ester), di-n-octyltin maleic acid polymer, di-n-octyltin dimaleic acid alkyl ester, di-n-octyltin dilaurate, di-n-octyltin Distearate, poly (thiobis-n-butyltin sulfide), monooctyltin tris (isooctylthiofuric acid alkyl ester), di-n-octyltin oxide, di-n-octyltin dichloride, tetra-n- Octyltin, di-n-octyltin diversate, di-n-octyltin alkyl mercaptide, di-
n-methyltin alkyl mercaptide and the like. The organotin compound may be used alone or in combination.
It is preferably from 1 to 500% by weight based on the leuco dye. When an isocyanate compound is added to the heat-sensitive agent, the content is preferably 1 to 500% by weight based on the isocyanate compound. If the content of the organotin compound is less than 1% by weight based on the isocyanate compound, a sufficient effect cannot be obtained. Further, even if it is used in an amount exceeding 500% by weight, the performance is not improved, and the cost is disadvantageous.

Further, N-stearyl-N ′-(2-hydroxyphenyl) urea, N-stearyl-N ′-(3-hydroxyphenyl) urea, N-stearyl-N ′-(3-hydroxyphenyl) urea, Stearyl-N ′-(4-hydroxyphenyl) urea, p-stearoylaminophenol, o-stearoylaminophenol, p-lauroylaminophenol, p-butyrylaminophenol, m-acetylaminophenol, o-acetylaminophenol, p-acetylaminophenol, o-butylaminocarbonylphenol, o-stearylaminocarbonylphenol, p-stearylaminocarbonylphenol, 1,1,3-tris (3-tert.
-Butyl-4-hydroxy-6-methylphenyl) butane, 1,1,3-tris (3-tert.-butyl-4)
-Hydroxy-6-ethylphenyl) butane, 1,1,
3-tris (3,5-di-tert.-butyl-4-hydroxyphenyl) butane, 1,1,3-tris (3-
tert. -Butyl-4-hydroxy-6-methylphenyl) propane, 1,2,3-tris (3-tert.
-Butyl-4-hydroxy-6-methylphenyl) butane, 1,1,3-tris (3-phenyl-4-hydroxyphenyl) butane, 1,1,3-tris (3-cyclohexyl-4-hydroxy-5) -Methylphenyl) butane, 1,1,3-tris (3-cyclohexyl-4-hydroxy-6-methylphenyl) butane, 1,1,3-
Tetra (3-phenyl-4-hydroxyphenyl) propane, 1,1,3,3-tetra (3-cyclohexyl-
4-hydroxy-6-methylphenyl) propane, 1,
1-bis (3-tert.-butyl-4-hydroxy-
It is also possible to add phenol compounds such as 6-methylphenyl) butane and 1,1-bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) butane.

The heat-sensitive recording sheet according to the present invention may contain a heat-fusible substance in order to improve the sensitivity. The heat-fusible substance preferably has a melting point of 60C to 180C, and particularly preferably has a melting point of 80C to 140C. For example, benzyl p-benzyloxybenzoate, stearamide, palmitamide,
N-methylol stearamide, β-naphthyl benzyl ether, N-stearyl urea, N, N′-distearyl urea, β-naphthoic acid phenyl ester,
-Hydroxy-2-naphthoic acid phenyl ester, β-
Naphthol (p-methylbenzyl) ether, 1,4-
Dimethoxynaphthalene, 1-methoxy-4-benzyloxynaphthalene, N-stearoylurea, 4-benzylbiphenyl, 1,2-di (m-methylphenoxy) ethane, 1-phenoxy-2- (4-chlorophenoxy)
Examples thereof include ethane, 1,4-butanediol phenyl ether, dimethyl terephthalate, metaterphenyl, dibenzyl oxalate, and oxalic acid (P-chlorobenzyl) ester.

The above-mentioned heat-fusible substance may be used alone or as a mixture. In order to obtain a sufficient thermal response, 10 to 300% by weight based on the isocyanate compound is used.
It is preferably used, and more preferably 20 to 250% by weight. To make a thermal recording sheet,
These isocyanate compounds, leuco dyes, amino compounds, imino compounds, acidic developers, heat-fusible substances or organotin compounds are dispersed in the form of a dispersion and coated on a support together with other necessary components and heat-sensitive. It must be a recording layer. The dispersion can be prepared by pulverizing one or more of these compounds in an aqueous solution containing a compound having a dispersing ability such as a water-soluble polymer or a surfactant. The particle diameter of each dispersion is preferably about 1 μm.

In addition, the thermal recording layer contains diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin and the like as pigments. You can also. In addition, for the purpose of preventing head abrasion and sticking, zinc stearate, higher fatty acid metal salts such as calcium stearate, paraffin,
Waxes such as paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, caster wax, etc .; dispersants such as dioctyl sodium sulfosuccinate; ultraviolet absorbers such as benzophenone and benzotriazole; surfactants and fluorescent dyes Etc. can be contained as needed.

As the binder used for the heat-sensitive recording layer, various binders usually used can be used. Examples of such binders include starches, hydroxyethyl cellulose, methyl cellulose,
Carboxymethylcellulose, gelatin, casein, polyvinyl alcohol, modified polyvinyl alcohol, sodium polyacrylate, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene / maleic anhydride copolymer Water-soluble binders such as alkali salts of ethylene, alkali salts of ethylene / maleic anhydride copolymers, and water-insoluble latexes such as styrene / butadiene copolymers, acrylonitrile / butadiene copolymers, and methyl acrylate / butadiene copolymers Binders and the like.

The heat-sensitive recording sheet according to the present invention comprises a support and a heat-sensitive recording layer which develops color by heating. As the support, paper is mainly used, but in addition to paper, various woven fabrics, nonwoven fabrics, synthetic resin films, laminated paper, synthetic paper, metal foil, or composite sheets obtained by combining these are optionally used according to the purpose. be able to. The thermal recording layer may be composed of a single layer or a plurality of layers. For example, each color forming component may be contained one layer at a time to form a multilayer structure. Further, a protective layer consisting of one or more layers may be provided on the heat-sensitive recording layer, or an intermediate layer consisting of one or more layers may be provided between the support and the heat-sensitive recording layer. Good. This heat-sensitive recording layer can be obtained by mixing each aqueous dispersion obtained by finely pulverizing each color-forming component or other components, a binder and the like, applying the mixture on a support, and drying.

[0065]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the following examples. In addition, each physical property was evaluated by the following methods. <Sensitivity> A printing tester manufactured by Okura Electric Co., Ltd., and the thermal head applied voltage was 2 using Kyocera KJT-256-8MGF1.
The color density at a 4 V pulse width of 1.5 msec was measured with an optical densitometer. <Plasticizer resistance> A thermosensitive recording sheet is sandwiched between vinyl chloride wraps or vinyl chloride files, and 300 g / c from the top.
m ² , and allowed to stand at 40 ° C. for 24 hours. After the standing, the density of the printed portion and the unprinted portion (background) was visually evaluated.
Those with little decoloration of print density were regarded as having good print storability.
In addition, a material having less scalp was regarded as having good storability. <Heat resistance> The heat-sensitive recording sheet was allowed to stand for 24 hours in an environment of 60 ° C. and 25% RH, and the discoloration density of the background was visually evaluated. . <Melting point> Melting point measuring machine YAZAWA TYPE BY-
Using No. 2, the temperature was raised at a rate of about 1 ° C./min while observing under a microscope, and the temperature at which melting began was visually judged. <Infrared absorption spectrum> Measured using IR-810 manufactured by JASCO Corporation.

[0066]

Example 1 2,4-Toluene diisocyanate 140
g of a solvent, 30 g of trimethyl phosphate and 30 g of ethylene glycol diacetate were added thereto, and 2.9 g of water was added thereto.
The reaction was performed at 0 ° C. for 30 minutes. The precipitated white solid was collected by filtration, washed with hexane, and dried in vacuo overnight to obtain 40 g of a white crystalline compound. The melting point and infrared absorption spectrum of this compound were measured. The melting point was 180 ° C., and the infrared absorption spectrum showed characteristic sharp peaks near 1590, 1650 and 2290 cm ⁻¹ .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Also, 3
70 g of dibutylamino-6-methyl-7-anilinofluoran in 8% by weight aqueous solution of polyvinyl alcohol 130
g with sand grinder (vessel capacity 400m
l, manufactured by Imex Co., Ltd.) and pulverized and dispersed at 2000 rpm for 3 hours to obtain a dispersion.

Also, 70 g of parabenzylbiphenyl was added to 8
A dispersion was obtained by grinding and dispersing with a sand grinder (vessel capacity 400 ml, manufactured by IMEX Co., Ltd.) at 130 rpm for 3 hours together with 130 g of an aqueous solution of polyvinyl alcohol by weight. In addition, 10 g of calcium carbonate is added to 30 pieces of water.
g and mixed by stirring with a stirrer to obtain a dispersion.

These dispersions were prepared by adding 20 parts by weight of the solid dispersion of the above compound dispersion to 3-dibutylamino-6-methyl-
10 parts by weight of dry solids of the 7-anilinofluoran dispersion, 25 parts by weight of dry solids of the parabenzylbiphenyl dispersion, 40 parts by weight of dry solids of the calcium carbonate dispersion,
Further, a ratio of a dry solid content of 20 parts by weight of a zinc stearate dispersion having a solid content concentration of 16% by weight and a dry solids content of 15% by weight of polyvinyl alcohol of 15 parts by weight (dry basis)
To obtain a coating liquid.

This coating solution was applied to a base paper having a weighing of 50 g / m ² with a rod number 10 of a bacoater, dried and treated with a super calender to obtain a heat-sensitive recording sheet. The evaluation result of the sensitivity was as good as the optical density of 1.1. The evaluation result of the degree of discoloration (heat resistance) of the background due to heat was good with little discoloration. The evaluation result of the covering property with the vinyl chloride wrap was good with little discoloration. Table 1
Shown in

[0071]

Example 2 2,4-Toluene diisocyanate 140
g of a solvent, 30 g of trimethyl phosphate and 30 g of ethylene glycol diacetate were added thereto, and 1.3 g of water was added thereto.
The reaction was performed at 30 ° C. for 2 hours. After the reaction, toluene was added to the residue obtained by distillation under reduced pressure to dissolve the residue, and then hexane was added to precipitate white crystals. The precipitated white solid was collected by filtration, washed with hexane, and dried under vacuum overnight to obtain 33 g of a white compound. Melting point was 148 ° C. In addition, infrared absorption spectra are 1600, 1720, and 22.
A characteristic sharp peak was observed around 90 cm ^-1 .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0073]

Example 3 2,4-Toluene diisocyanate 140
g was dissolved in 200 g of toluene, 74 g of aniline was gradually added, and the mixture was reacted at room temperature for 1 hour to precipitate white crystals. The precipitated white solid was collected by filtration, washed with hexane, and dried in vacuo overnight to give a white crystalline compound 19
7 g were obtained. The melting point was 170 ° C. Further, in the infrared absorption spectrum, characteristic sharp peaks were observed around 1600, 1650 and 2290 cm ^-1 .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0075]

Example 4 2,4-Toluene diisocyanate 140
g was dissolved in 200 g of toluene, 37 g of p-phenylenediamine was gradually added, and the mixture was reacted at room temperature for 3 hours to precipitate white crystals. The precipitated white solid was recovered by filtration, washed with hexane, and dried in vacuo overnight to obtain 120 g of a white crystalline compound.

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0077]

Example 5 2,4-Toluene diisocyanate 140
g was dissolved in 60 g of toluene, 3.7 g of aniline was gradually added, and the mixture was reacted at 100 ° C. for 1 hour. As a result, white crystals were precipitated. The precipitated white solid was collected by filtration, washed with hexane, and dried in vacuo overnight to give white compound 1.
8 g were obtained. The melting point was 130 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed around 1720 and 2290 cm ^-1 .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0079]

Example 6 2,4-Toluene diisocyanate 140
g was dissolved in 60 g of toluene, 4 g of p-phenylenediamine was gradually added, and the mixture was reacted at 100 ° C. for 5 hours to precipitate white crystals. The precipitated white solid was collected by filtration, washed with hexane, and dried in vacuo overnight to obtain 20 g of a white compound.

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0081]

Example 7 2,4-Toluene diisocyanate 100
g and 100 g of pyridine were dissolved in 33 g of toluene and reacted at room temperature for 24 hours. The resulting precipitate was filtered, washed with hexane, and vacuum dried overnight to obtain 40 g of an off-white compound. Melting point was 160 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed at around 1760 and 2290 cm ^-1 .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 1. Table 1 summarizes the results
Shown in

[0083]

Examples 8 to 11 40 g of 3,3′-diaminodiphenyl sulfone was added to a 10% by weight aqueous solution of polyvinyl alcohol 1
60 g, and sand grinder (vessel capacity 4
00ml, manufactured by Imex Corporation), 2000 rpm
For 3 hours to obtain a dispersion. The thermosensitive recording was performed in the same manner as in each example except that the obtained dispersion was added to the dispersion described in Examples 1, 2, 3, and 7 at a ratio of 20 parts by weight of dry solid content to prepare a coating liquid. A sheet was prepared and evaluated.
Table 2 summarizes the results.

[0084]

Example 12 40 g of 1,3-diimino-4,5,6,7-tetrachloroisoindoline, which is an imino compound, was added to 160 g of a 10% by weight aqueous solution of polyvinyl alcohol to the coating solution of Example 1, and a sand grinder ( Vessel capacity 400ml, manufactured by Imex Co., Ltd., rotation speed 2000r
A thermosensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that a dispersion obtained by pulverizing and dispersing at pm for 3 hours was added at a ratio of 2 parts by weight of dry solids. Table 2 summarizes the results.

[0085]

Example 13 40 g of 3,3'-diaminodiphenylsulfone was added to 160 g of a 10% by weight aqueous solution of polyvinyl alcohol to the coating solution of Example 12, and the mixture was subjected to a sand grinder (400 ml vessel volume, manufactured by Imex Co., Ltd.) at a rotation speed of 2000 rpm. A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 12, except that the dispersion obtained by pulverizing and dispersing for a time was added at a ratio of 20 parts by weight of dry solids. Table 2 summarizes the results.

[0086]

Embodiment 14 In the coating solution of Embodiment 8, 2, 2
70 g of bis (4-hydroxyphenyl) propane
130% by weight aqueous solution of polyvinyl alcohol
A heat-sensitive material was prepared in the same manner as in Example 8, except that a dispersion obtained by pulverizing and dispersing a sand grinder (Vessel capacity: 400 ml, manufactured by Imex Co., Ltd.) at a rotation speed of 2000 rpm for 3 hours and adding a dry solid content of 5 parts by weight was added. A recording sheet was created and evaluated. Table 2 summarizes the results.

[0087]

Example 15 Instead of the dispersion of 3-dibutylamino-6-methyl-7-anilinofluoran in Example 1, 1,3-diimino-4,5,6,7-
40 g of tetrachloroisoindoline was added to 160 g of a 10% by volume aqueous solution of polyvinyl alcohol, and a sand grinder (400 ml of vessel volume, manufactured by Imex Co., Ltd.) was added.
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1, except that a dispersion obtained by pulverizing and dispersing at 2000 rpm for 3 hours was added at a ratio of 30 parts by weight of dry solids. Table 3 summarizes the results.

[0088]

Example 16 40 g of 3,3'-diaminodiphenylsulfone was added to 160 g of a 10% by weight aqueous solution of polyvinyl alcohol to the coating solution of Example 15, and a sand grinder (Vessel capacity: 400 ml, manufactured by Imex Co., Ltd.) was used. A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 15 except that a dispersion obtained by pulverizing and dispersing for a time was added at a ratio of 20 parts by weight of a dry solid content. Table 3 summarizes the results.

[0089]

Examples 17 to 20 2 g of di-n-octyltin oxide (Stann OO manufactured by Sankyoki Seisaku Co., Ltd.) was added to 4 g of a 2.5% by weight aqueous solution of polyvinyl alcohol and 2.
The mixture was dispersed with 75 g and 1.25 g of ethanol on a paint shaker for 4 hours to obtain a dispersion. The obtained di-n
A heat-sensitive recording sheet was prepared in the same manner as in each example except that the octyltin oxide dispersion was added to the dispersion described in Examples 1, 8, 14, and 16 at a ratio of 2 parts by weight of dry solid content to prepare a coating liquid. Created and evaluated. Table 1 summarizes the results
3 is shown.

[0090]

Example 21 2,4-Toluene diisocyanate 14
To 0 g, 30 g of trimethyl phosphate and 30 g of ethylene glycol diacetate as solvents were added, and 2.9 g of water was added thereto, followed by a reaction at 30 ° C. for 30 minutes. The precipitated white solid was collected by filtration, washed with hexane, and dried in vacuum overnight to obtain 20 g of a white crystalline compound. The melting point and infrared absorption spectrum of this compound were measured. The melting point was 180 ° C.
The infrared absorption spectrum was 1590, 1650, 2290
A characteristic sharp peak was observed around cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Also,
70 g of 3-dibutylamino-6-methyl-7-anilinofluoran together with 130 g of a 4.3% by weight aqueous solution of polyvinyl alcohol in a sand grinder (vessel capacity 40)
0 ml, manufactured by IMEX Co., Ltd.) and crushed and dispersed at a rotation speed of 2000 rpm for 3 hours to obtain a dispersion.

Further, 70 g of parabenzylbiphenyl was pulverized together with 130 g of a 4.3% by weight aqueous solution of polyvinyl alcohol in a sand grinder (vessel capacity: 400 ml, manufactured by IMEX Co., Ltd.) for 3 hours at a rotation speed of 2000 rpm.
Dispersion gave a dispersion. Further, 20 g of calcium carbonate was mixed with 60 g of water, and the mixture was stirred and dispersed with a stirrer to obtain a dispersion.

The coating liquid was 30 parts by weight of the above compound dispersion, 3 parts by weight,
7 parts by weight of -dibutylamino-6-methyl-7-anilinofluoran dispersion, parabenzylbiphenyl dispersion 18
Parts by weight, 37 parts by weight of a calcium carbonate dispersion, 7 parts by weight of a zinc stearate dispersion having a solid content concentration of 31.5% by weight, and 36 parts by weight of a 15% by weight polyvinyl alcohol were further mixed and adjusted by stirring. .

This coating solution was applied on a base paper having a weighing of 50 g / m ² with a rod number 10 of a bacoater, dried and treated with a super calender to obtain a heat-sensitive recording sheet. The evaluation result of the sensitivity was as good as the optical density of 1.1. The evaluation result of the degree of discoloration (heat resistance) of the background due to heat was good with little discoloration. The evaluation result of the covering property with the vinyl chloride file was good with little discoloration. The printed portion was also legible and good. Table 4 summarizes the results
Shown in

[0095]

Example 22 2,4-Toluene diisocyanate 14
0 g was dissolved in 200 g of toluene, and then 74 g of aniline was dissolved.
Was gradually added, and the mixture was reacted at room temperature for 1 hour, whereby white crystals were precipitated. After collecting the precipitated white solid by filtration,
Wash with hexane and dry overnight in vacuo to give white crystalline compound 9
5 g were obtained. The melting point was 170 ° C. Further, in the infrared absorption spectrum, characteristic sharp peaks were observed around 1600, 1650 and 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0097]

Example 23 2,4-Toluene diisocyanate 85
g and 16 g of methanol were dissolved in 160 g of toluene and reacted at room temperature for 3 hours. The resulting precipitate was filtered, washed with hexane, and dried in vacuo overnight to give a white compound 5
8.5 g were obtained. The melting point and infrared absorption spectrum of this compound were measured. Melting point was 80 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed around 1540, 1610, and 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0099]

Example 24 2,4-Toluene diisocyanate 10
0 g and 27 g of phenol are dissolved in 160 g of toluene,
The temperature was gradually raised from room temperature to 100 ° C., and the reaction was carried out at 100 ° C. for 1 hour. After concentrating the reaction solution, hexane was added, whereby a white precipitate was formed. After the generated precipitate was filtered, the precipitate was washed with hexane and dried under vacuum overnight to give a white compound 7.
7 g were obtained. The melting point was 70 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed around 1550, 1700, and 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0101]

Example 25 2,4-Toluene diisocyanate 10
0 g was dissolved in 160 g of toluene, and a solution in which 34 g of n-propylamine was dissolved in 160 g of toluene was gradually added dropwise. After the addition, the mixture was reacted at room temperature for 1 hour. The resulting precipitate was filtered, washed with hexane, and dried under vacuum overnight to obtain 55.6 g of a white compound. Melting point 210
° C. The infrared absorption spectrum was 1650,
A characteristic sharp peak was observed around 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0103]

Example 26 2,4-Toluene diisocyanate 10
0 g was dissolved in 160 g of toluene, and a solution of 21 g of 1-methylpropylamine dissolved in 160 g of toluene was gradually added dropwise. After the addition, the mixture was allowed to react at room temperature for 1 hour. As a result, a white precipitate was formed. After filtering the generated precipitate,
After washing with hexane and vacuum drying overnight, 53 g of a white compound was obtained. Melting point was 315 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed at around 1650 and 2290 cm ^-1 .

Next, 2 g of this compound was taken, and 2.5% by weight
It was pulverized and dispersed for 45 minutes with a paint shaker together with 8 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. continue,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that the dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 1.

[0105]

Example 27 To 100 g of Cosmonate T-80 (manufactured by Mitsui Toatsu Chemicals), 30 g of trimethyl phosphate and 30 g of ethylene glycol diacetate were added as solvents, and 2.1 g of water was added thereto.
Was added, and the mixture was reacted at room temperature for 1 hour. As a result, white crystals were precipitated. The precipitated white solid was collected by filtration, washed with hexane, and dried under vacuum overnight to obtain 31 g of a white crystalline compound. The melting point was 150 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed at around 1650 and 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight was obtained.
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0107]

Example 28 After dissolving 100 g of Cosmonate T-80 (manufactured by Mitsui Toatsu Chemicals) in 160 g of toluene, a solution of 53 g of aniline dissolved in 160 g of toluene was gradually added, followed by reaction at room temperature for 1 hour. Crystals precipitated. The precipitated white solid was collected by filtration, washed with hexane, and vacuum dried overnight to obtain 147 g of a white compound. Melting point was 165 ° C. In the infrared absorption spectrum, characteristic sharp peaks were observed at around 1600 and 2290 cm ^-1 .

Next, 6 g of this compound was taken, and 2.5% by weight
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0109]

Example 29 150 g of Cosmonate T-80 (manufactured by Mitsui Toatsu Chemicals) and 150 g of pyridine were dissolved in 50 g of toluene and reacted at room temperature for 12 hours. The resulting precipitate was filtered, washed with hexane, and dried in vacuum overnight to obtain 38 g of an off-white compound. The melting point was 140 ° C. The infrared absorption spectrum was 1710, 2290 cm ^-1.
A characteristic sharp peak was observed in the vicinity.

Next, 6 g of this compound was taken, and 2.5% by weight was obtained.
The mixture was pulverized and dispersed for 45 minutes with a paint shaker together with 24 g of an aqueous polyvinyl alcohol solution to obtain a dispersion. Subsequently, a heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 21 except that a dispersion of the above compound was used instead of the dispersion of the compound obtained in Example 21. The results are summarized in Table 4.

[0111]

Examples 30 to 35 40 g of 3,3'-diaminodiphenylsulfone was added to 160 g of a 2.5% by weight aqueous solution of polyvinyl alcohol, and a sand grinder (vessel capacity: 400 ml, manufactured by Imex Co.) was used.
By crushing at pm for 3 hours, a dispersion was obtained. Dispersion 2 obtained
5 parts by weight of Examples 21, 22, 23, 24, 27, 28
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in each example except that it was added to the coating liquid described in (1). Table 5 summarizes the results.

[0112]

Examples 36 to 37 After the heat-sensitive recording sheets obtained in Examples 30 and 31 were stored under humidification and heating conditions of 60 ° C. and 90% RH for 3 days, the degree of discoloration of the background was evaluated.
The results were good with little discoloration. In addition, when the sensitivity of the stored heat-sensitive recording sheet was examined, the sensitivity before the storage test was approximately maintained and was good. The results are summarized in Table 6.

[0113]

Comparative Example 1 In place of the isocyanate compound synthesized in Example 1, 4,4 ′, 4 ″ -triisocyanato-2,
A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that 5-dimethoxytriphenylamine was used. The results are summarized in Table 1.

[0114]

Comparative Example 2 Instead of the isocyanate compound used in Example 15, 4,4 ', 4''-triisocyanato-
A heat-sensitive recording sheet was prepared in the same manner as in Example 15 except that 2,5-dimethoxytriphenylamine was used.
An evaluation was performed. Table 2 summarizes the results.

[0115]

Comparative Example 3 Instead of the isocyanate compound used in Example 26, 4,4 ′, 4 ″ -triisocyanato-
A heat-sensitive recording sheet was prepared in the same manner as in Example 26 except that 2,5-dimethoxytriphenylamine was used.
An evaluation was performed. Table 2 summarizes the results.

[0116]

Comparative Example 4 A heat-sensitive recording sheet was prepared and evaluated in the same manner as in Example 1 except that 2,2-bis (4-hydroxyphenyl) propane was used instead of the isocyanate compound synthesized in Example 1. Was done. The results are summarized in Table 1.

[0117]

Comparative Example 5 Instead of the isocyanate compound synthesized in Example 21, 4,4 ′, 4 ″ -triisocyanato-
A thermosensitive recording sheet was prepared in the same manner as in Example 21 except that 2,5-dimethoxytriphenylamine was used.
An evaluation was performed. The results are summarized in Table 4.

[0118]

Comparative Example 6 Instead of the isocyanate compound used in Example 30, 4,4 ', 4''-triisocyanato-
A thermosensitive recording sheet was prepared in the same manner as in Example 30, except that 2,5-dimethoxytriphenylamine was used.
An evaluation was performed. Table 5 summarizes the results.

[0119]

Comparative Example 7 A heat-sensitive recording sheet was prepared in the same manner as in Example 30, except that diphenylmethane diisocyanate (melting point: 38 ° C.) was used instead of the isocyanate compound used in Example 30. After the obtained heat-sensitive recording sheet was stored under the humidification and heating conditions of 60 ° C. and 90% RH for 3 days in the same manner as in Example 36, the degree of discoloration of the background was evaluated. As a result, the background was colored. . Further, when the sensitivity of the stored heat-sensitive recording sheet was examined, the sensitivity was considerably lower than the sensitivity before the storage test and was insufficient. The results are summarized in Table 6.

[0120]

[Table 1]

[0121]

[Table 2]

[0122]

[Table 3]

[0123]

[Table 4]

[0124]

[Table 5]

[0125]

[Table 6]

[0126]

By using a specific isocyanate compound as a heat-sensitive agent, a heat-sensitive recording sheet having excellent image storability and sensitivity can be provided at low cost.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B41M 5/18 103 108 108

Claims (12)

[Claims] 1. A heat-sensitive agent containing an isocyanate adduct compound having a melting point of 40 ° C. or higher, and a compound capable of thermally reacting with the isocyanate adduct compound to form a color. 2. A heat-sensitive agent containing an isocyanate adduct compound represented by the following formula (a) and a compound capable of thermally reacting with the isocyanate adduct compound to form a color. Embedded image (Here, n represents an integer of 1 to 2. The hydrogen atom of the benzene ring may be substituted with an aromatic compound residue, an aliphatic compound residue, or a heterocyclic compound residue. May have a substituent.The following formulas (I) to (I)
Same in (X). ) 3. A heat-sensitive agent containing an isocyanate compound represented by at least one of the following formulas (I) to (X) and a compound capable of thermally reacting with the isocyanate compound to form a color. Embedded image Embedded image Embedded image (R ₁ represents an aromatic compound residue, a heterocyclic compound residue, or an aliphatic compound residue. Further, each residue may have a substituent. The following formulas (IV) and (V) , (VI)
Same in. ) Embedded image Embedded image Embedded image Embedded image (R ₂ represents an aromatic compound residue, a heterocyclic compound residue, or an aliphatic compound residue. Further, each residue may have a substituent.) (R ₃ represents an aromatic compound residue which may have a substituent, a heterocyclic compound residue which may have a substituent, or an aliphatic compound residue or an inorganic compound residue which may have a substituent. ). (R ₄ and R ₅ each independently represent an aromatic compound, a heterocyclic compound, or an aliphatic compound residue. Each residue may have a substituent. R ₄ and R ₅ are mutually cyclic. A structure may be formed.) 4. A leuco dye as a compound capable of forming a color by a thermal reaction with an isocyanate compound.
The heat-sensitive agent according to any one of the above. 5. The heat-sensitive agent according to claim 1, further comprising an amino compound. 6. The heat-sensitive agent according to claim 4, which contains an imino compound represented by the following formula (XI) as a compound capable of thermally reacting with the isocyanate compound to form a color. Embedded image (In the formula, φ represents an aromatic compound residue capable of forming a conjugated system with adjacent C = N.) 7. The heat-sensitive agent according to claim 6, comprising an amino compound. 8. The heat-sensitive agent according to claim 1, further comprising an imino compound represented by the formula (XI) as a compound capable of thermally reacting with the isocyanate compound to form a color. 9. The heat-sensitive agent according to claim 8, comprising an amino compound. 10. The heat-sensitive agent according to claim 1, further comprising an acidic developer. 11. The composition according to claim 1, which comprises an organotin compound.
0. The heat-sensitive agent according to any one of 0. 12. A heat-sensitive recording sheet provided with a heat-sensitive coloring layer containing the heat-sensitive agent according to claim 1 on a support.