JPH1044609A - Heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the generation of first coat fog and reduce the surface coat color change by using a crosslinking agent having a specified ratio of solubility of a developer into a crosslinking agent water solution or crosslinking dispersion liquid. SOLUTION: When the solubility of 2,2-bis (p-hydroxyphenyl) propane to crosslinking water solution of solid content density of 10% or dispersion liquid of 100g, 2,2-bis(p-hydroxyphenyl) propane of 0.5g or more is dissolved by an epichlorohydrin crosslinking agent, 0.01g or less is dissolved by an aziridine compound crosslinking agent. A crosslinking agent having the solubility of less than 0.5g is selected for the purpose of not generating the first coat fog. N,N-hexamethylene-1,6-bis (1-aziridine carboxylamide and N,N-toluene-2,4-bis (1-aziridine carboxyamide) out of aziridine compound crosslinking agents is provided with the solubility of 0.01g or less to water of 100g of the crosslinking agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material, more specifically, a heat-sensitive recording material comprising a heat-sensitive coloring layer containing a leuco dye and a color developer provided on a support, and a protective layer provided on the color-forming layer. About.

[0002]

2. Description of the Related Art A thermosensitive recording material is a recording material having a structure in which a thermosensitive coloring layer which develops a color by heating is formed on a support such as paper, synthetic paper, resin film, etc. Is performed. Compared to other recording methods, this recording method does not require processing such as development and fixing, can be recorded in a short time using a relatively simple device, and is inexpensive in terms of cost. Copy,
It is used in various fields such as facsimile, ticket, label, and recorder. However, there are still problems with the reliability of images when used in labels and the like, that is, plasticizer resistance, oil resistance, water resistance, heat resistance, light resistance, and the like, and a solution is required. Conventionally, as a method for solving these problems, it has been known to add an auxiliary agent to the thermosensitive coloring layer, or to provide a protective layer on the thermosensitive coloring layer. By the way, 2,2-bis (p-hydroxyphenyl) is a typical color developer that causes a leuco dye to develop color when heated.
There is propane, which is also known as a relatively inexpensive developer for facsimile and the like.

[0003]

However, a resin, a pigment, or a cross-linking agent is further used as a main component in the protective layer in many cases. Incorporation of -bis (p-hydroxyphenyl) propane has a disadvantage of causing background fogging. The present invention relates to 2,2-bis (p
-Hydroxyphenyl) propane, no background fogging occurs even when a cross-linking agent is used in the protective layer, and furthermore, there is little demand for improvement in the label field. The purpose is to obtain a recording material.

[0004]

According to the present invention, first, a leuco dye and 2,2-bis as a color developing agent are provided on a support.
In a thermosensitive recording material provided with a thermal color-developing layer containing (p-hydroxyphenyl) propane and further provided with a protective layer containing a resin and a crosslinking agent on the color-developing layer, the crosslinking agent has a solid content of 10%. % Of the 2,2-bis (p-hydroxyphenyl) in the aqueous solution of the crosslinking agent or the dispersion of the crosslinking agent.
There is provided a heat-sensitive recording material characterized by using a crosslinking agent having a solubility of propane of 0.5 g or less per 100 g of the aqueous solution of the crosslinking agent or 100 g of the dispersion of the crosslinking agent. Secondly,
The heat-sensitive recording material according to the first aspect, wherein the crosslinking agent is an aziridine compound. Third, there is provided a heat-sensitive recording material according to the second aspect, wherein the aziridine compound has a solubility of 0.05 g or less in 100 g of water. Fourth, in the heat-sensitive recording material described in the fourth, the aziridine compound is N, N'-toluene-2,4-bis.
(1-aziridincarboxamide) or N, N'-hexamethylene-1,6-bis (1-aziridincarboxamide) is provided. Fifth, in any one of the thermosensitive recording materials described in the first to fourth aspects, the protective layer further contains a stilbene-based fluorescent whitening agent having an absorption peak at a light wavelength of 340 to 400 nm. A heat-sensitive recording material is provided.

Hereinafter, the present invention will be described in detail. The present inventors have examined the above-mentioned disadvantages and found that 2,2-bis (p-
(Hydroxyphenyl) propane has the property of dissolving with respect to the cross-linking agent, and in particular, the epichlorohydrin compound-based cross-linking agent dissolves 2,2-bis (p-hydroxyphenyl) propane and easily causes background fogging. It has been found that an aziridine compound-based crosslinking agent hardly dissolves 2,2-bis (p-hydroxyphenyl) propane and does not cause background fogging. Further, the aziridine compound has an ultraviolet absorbing ability, and when used in combination with 2,2-bis (p-hydroxyphenyl) propane, which is superior in light resistance as compared with other color developers, the effect on light resistance is further enhanced. In addition, the stilbene-based fluorescent whitening agent also has an ultraviolet absorbing ability, and it has been found that the combined use of an aziridine compound and a stilbene-based fluorescent whitening agent further improves the light resistance, leading to the present invention.

According to the study of the present inventors, the solid content concentration was 1%.
2, 100 g of 0% aqueous solution or dispersion of crosslinking agent
When the solubility of 2-bis (p-hydroxyphenyl) propane was measured, the epichlorohydrin-based cross-linking agent that causes background fog dissolves 0.5 g or more of 2,2-bis (p-hydroxyphenyl) propane. . In contrast, at most 0.01 g of an aziridine compound-based crosslinking agent that hardly causes background fog dissolves (see Table 2 below). From these results, the present inventors found that at most 0.5 g under the above-mentioned measurement conditions was used in order to prevent background fog.
That it is necessary to select a crosslinking agent that has a solubility of less than
Among the aziridine compound-based crosslinking agents, N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) and N, N'-toluene-2,4-bis (1-
Aziridine carboxamide) hardly causes background fog, and the solubility of these crosslinking agents in 100 g of water is 0.01 g or less. Therefore, an aziridine-based crosslinking agent having a solubility in 100 g of water of at most 0.05 g or less can be selected. It was presumed that favorable results were obtained in the prevention of background fogging.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, specific examples of the crosslinking agent used in the protective layer of the present invention include, for example, trimethylolpropane-β-aziridinylpropionate, N, N′-hexamethylene-1,6. -Bis (1-aziridinecarboxamide), tetramethylolmethane-tri-β-aziridinylpropionate, N, N′-toluene-2,4-
Bis (1-aziridinecarboxamide) and the like, among which N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) and N, N'-
As described above, toluene-2,4-bis (1-aziridinecarboxamide) is preferable.

In the present invention, the resin used as the main component for forming the protective layer is arbitrarily selected from known water-soluble resins and water-soluble emulsion resins. In this case, specific examples of the water-soluble resin include polyvinyl alcohol and modified products thereof, starch and derivatives thereof, cellulose derivatives, poly (meth) acrylic acid, and alkali salts thereof, poly (meth) acrylamide, and the like. And alkali salts of (meth) acrylamide and their alkali salts, styrene / maleic anhydride copolymer alkali salts, polyvinylpyrrolidone, polyethyleneimine, sodium alginate, gelatin, casein and the like. Specific examples of the aqueous emulsion resin include an acrylic copolymer, an acrylic acid copolymer, a (meth) acrylate ester copolymer, a urethane resin, an epoxy resin, a vinyl acetate (co) polymer, and a chloride. Emulsions such as vinylidene (co) polymer and vinyl chloride (co) polymer, and latex such as styrene / butadiene copolymer and styrene / butadiene / acrylic copolymer are exemplified.

Further, examples of stilbene-based fluorescent whitening agents which can be used in the protective layer of the present invention together with an aziridine compound to further improve light resistance include the following. 4,4'-bis (2-amino-4-anilino-1,3,5-triazinyl-6-amino) stilbene-2,2'-disulfonic acid, 4,4'-bis (2,4-
Dianilino-1,3,5-triazin-6-yl-amino) stilbene-2,2'-disulfonate disodium, 4,4'-bis (2-anilino-4-hydroxyethylamino-1,3,5 -Triazinyl-6-amino)
Stilbene disulfonic acid, sodium 4,4′-bis {2-anilino-4-di (hydroxyethyl) amino-1,3,5-triazinyl- (6) -amino} stilbene-2,2′-disulfonate, , 4'-bis [2- (2-methylanilino) -4-bis (hydroxyethyl) amino-
1,3,5-triazinyl-6-amino] stilbene-
Sodium 2,2'-disulfonate, 4,4'-bis
{2- (m-sulfophenylamino) -4- (2-hydroxypropyl) amino-1,3,5-triazinyl-6
Amino} stilbene-2,2'-disulfonate sodium, 4- [2-p-sulfoanilino-4-bis (hydroxyethyl) amino-1,3,5-triazinyl-6-
Amino] -4 '-[2-m-sulfoanilino-4-bis
(Hydroxyethyl) amino-1,3,5-triazinyl-6-amino] stilbene-2,2′-disulfonate sodium, 4,4′-bis {2-sodiumsulfanyl-4-di (hydroxyethyl) amino Sodium-1,3,5-triazinyl- (6) -amino} stilbene-2,2'-disulfonate, 4,4'-bis [4- [3-acetylamino-4- (4,8-disulfo- 2-naphthylazo)] anilino-6- (3-carboxypyridinio) -1,
3,5-triazin-2-ylamino] -2,2′-disulfostilbene-dihydroxide hexasodium salt,
4,4′-bis [4- [3-acetylamino-4- (4,4
8-disulfo-2-naphthylazo)] anilino-6-chloro-1,3,5-triazin-2-ylamino] -2,
2′-stilbenedisulfonic acid = hexasodium salt, 4,
4'-bis [4- [3- [3-carboxy-5-hydroxy-1- (p-sulfophenyl) -4-pyrazolylazo] -4-sulfoanilino] -6-chloro-1,3,5
-Triazin-2-ylamino] -2,2'-stilbenedisulfonic acid = octasodium salt, 4,4'-bis [4
-Chloro-6- [3- [1- (2-chloro-5-sulfophenyl) -5-hydroxy-3-methyl-4-pyrazolylazo] -4-sulfoanilino] -1,3,5-triazine-2 -Ylamino] -2,2'-stilbene disulfonic acid = hexasodium salt, 4,4'-bis [6- [N-
(2-Cyanoethyl) -N- [2- (2-hydroxyethoxy) ethyl] amino] -4- (2,5-disulfoanilino)
-1,3,5-triazin-2-ylamino] -2,
2′-stilbenedisulfonic acid = hexasodium salt, 4,
4′-bis [4-bis (2-hydroxypropyl) amino-6- (4-sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2′-stilbenedisulfonic acid = tetrasodium salt, 4- (4 amino-6-anilino-
1,3,5-triazin-2-ylamino) -4′-
(4,6-diamino-1,3,5-triazin-2-ylamino) -2,2′-stilbene disulfonic acid, 4-
Calcium (2,4-diamino-1,3,5-triazin-6-yl) amino-4 ′-(4-amino-2-chloro-6-yl) amino-2,2′-stilbenedisulfonate, , 4'-bis (4-amino-6-anilino-
1,3,5-triazin-2-ylamino) -2,2 ′
-Stilbene disulfonic acid, 4,4'-bis (4-amino-6-anilino-1,3,5-triazin-2-ylamino) -2,2'-stilbene disulfonic acid dipotassium, 4,4'-bis (4-amino-6-anilino-1,
Potassium hydrogen 3,5-triazin-2-ylamino) -2,2'-stilbenzidisulfonate, 4,4'-bis
(4-amino-6-chloro-1,3,5-triazine-
2-ylamino) -2,2'-stilbenedisulfonic acid, 4,4'-bis (4-amino-6-chloro-1,
3,5-triazin-2-ylamino) -2,2'-stilbene disulfonic acid dipotassium, 4,4'-bis (6
-Amino-4-chloro-1,3,5-triazine-2-
Ylamino) -2,2′-stilbene disulfonate calcium, 4,4′-bis (4-amino-6-chloro-
1,3,5-triazin-2-ylamino) -2,2 ′
-Potassium hydrogen stilbene disulfonate, sodium 4,4'-bis (4-amino-6-chloro-1,3,5-triazin-2-ylamino) -2,2'-stilbene disulfonate, 4,4 ' -Bis (4-amino-6-
Chloro-1,3,5-triazin-2-ylamino)-
Disodium 2,2'-stilbene disulfonic acid, 4,
4'-bis [4-anilino-6- (p-sulfoanilino)
-1,3,5-triazin-2-ylamino] -2,
2′-stilbene disulfonic acid = potassium salt (mono-, di-, tri- or tetra-salt), 4,4′-bis [4-anilino-
6- (2-hydroxyethylamino) -1,3,5-triazin-2-ylamino] -2,2′-stilbendisulfonic acid, 4,4′-bis [4-anilino-6- (2-
(Hydroxyethylamino) -1,3,5-triazine-
2-potassium 2-ylamino] -2,2'-stilbene disulfonic acid, 4,4'-bis [4-anilino-6- (2
-Hydroxyethylamino) -1,3,5-triazin-2-ylamino] -2,2'-potassium hydrogen hydrogen stilbene disulfonate, 4,4'-bis (4-anilino-6-
Methylamino-1,3,5-triazin-2-ylamino) -2,2'-stilbene disulfonate disodium, 4,4'-bis [4- (2,5-disulfoanilino)
-6- (2-hydroxypropylamino) -1,3,5-
Triazin-2-ylamino] -2,2′-stilbenedisulfonic acid, 4,4′-bis [6- (m-sulfoanilino) -4- (2-hydroxydiethylamino) -1,
3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [6- (m-sulfoanilino) -4- (2-hydroxypropylamino)
-1,3,5-triazin-2-ylamino] -2,
2'-stilbene disulfonic acid, 4,4'-bis [6-
(2-hydroxyethylamino) -4-anilino-1,
3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-bis (2
-Hydroxyethyl) amino-6-chloro-1,3,5
-Triazin-2-ylamino] -2,2'-stilbene disulfonic acid sodium hydrogen salt, 4,4'-bis (4-
Methylamino-6-phenylamino-1,3,5-triazin-2-ylamino) -2,2′-stilbendisulfonic acid, 4- [4-chloro-6-bis (2-hydroxyethyl) amino-1, 3,5-triazin-2-ylamino] -4 '-[4,6-bis [bis (2-hydroxyethyl) amino] -1,3,5-triazin-2-ylamino] -2,2'-stilbene Disulfonic acid, 4,
4'bis [4-anilino-6-bis (2-hydroxyethyl) amino-1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'bis [4-anilino -6-bis (2-hydroxyethyl) amino-1,3,5-triazin-2-ylamino]-
Dipotassium 2,2'-stilbene disulfonic acid, 4,
4'-bis [4-anilino-6-bis (2-hydroxyethyl) amino-1,3,5-triazin-2-ylamino] -2,2'-potassium hydrogen hydrogen stilbene disulfonate, 4,4'bis [4 -Anilino-6- [N- (2-hydroxyethyl) -N-methylamino] -1,3,5-
Trizin-2-ylamino] -2,2'-stilbene disulfonic acid dipotassium, 4,4'bis [4-anilino-6- [N- (2-hydroxyethyl) -N-methylamino] -1,3,3 5-triazin-2-ylamino]-
Potassium hydrogen 2,2′-stilbene disulfonate, 4,
4'-Bis [4- (diethylamino) -6- (2,5-disulfoanilino) -1,3,5-triazin-2-ylamino] -2,2'-stilbene disulfonic acid = sodium salt (monosalt, Salt, trisalt, tetrasalt, pentasalt or hexasalt),
4,4′-bis [6- (p-sulfamoylphenylamino) -4-bis (2-hydroxyethyl) amino-1,
3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-bis (2
-Hydroxyethyl) amino-6- (p-sulfamoylanilino) -1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-
Bis [4-bis (2-hydroxyethyl) amino-6-chloro-1,3,5-triazin-2-ylamino]-
Disodium 2,2'-stilbene disulfonic acid, 4,
4'-bis [6-bis (2-hydroxyethyl) amino-
4- (2,5-disulfoanilino) -1,3,5-triazin-2-ylamino] -2,2′-stilbenedisulfonic acid, 4,4′-bis [4-bis (2-hydroxyethyl) amino- 6- (m-sulfoanilino) -1,3,5
-Triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-bis (2-hydroxyethyl) amino-6- (p-sulfoanilino)-
1,3,5-triazin-2-ylamino] -2,2 ′
-Stilbene disulfonic acid, 4,4'-bis [4-bis
(2-Hydroxyethyl) amino-6- (m-sulfoanilino) -1,3,5-triazin-2-ylamino]-
2,2′-stilbene disulfonic acid potassium salt (monosalt,
Disodium, trisalt or tetrasalt), 4,4′-bis [4-bis (2
-Hydroxyethyl) amino-6- (p-sulfophenoxy-1,3,5-triazin-2-ylamino] -2,
2′-stilbene disulfonic acid, 4- [4-bis (2-
(Hydroxyethyl) amino-6- (p-sulfoanilino)
-1,3,5-triazin-2-ylamino] -4 '
[4-bis (2-hydroxyethyl) amino-6- (m-
Sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2′-stilbenedisulfonic acid, 4-
[4-bis (2-hydroxyethyl) amino-6- (p-
Sulfonylino) -1,3,5-triazin-2-ylamino] -4 '-[4-bis (2-hydroxyethyl) amino-6- (m-sulfonanilino) -1,3,5-triazin-2-ylamino ] -2,2'-stilbene disulfonic acid = sodium salt (mono-, di-, tri- or tetra-salt), 4
-[4-bis (2-hydroxyethyl) amino-6-methoxy-1,3,5-triazin-2-ylamino]-
4 '-(4-methoxy-6-morpholino-1,3,5-
Triazin-2-ylamino) -2,2'-stilbenedisulfonic acid, 4- [4-bis (2-hydroxyethyl)
Amino-6-methoxy-1,3,5-triazine-2-
Ylamino] -4 '-[4- (2-hydroxysulfonylethylamino) -6-methoxy-1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4- (4-anilino -6-methoxy-1,3,3
5-triazin-2-ylamino) -4 '-(4-chloro-6-methoxy-1,3,5-triazin-2-ylamino) -2,2'-stilbene disulfonic acid disodium, 4- (4- Anilino-6-methoxy-1,3,5-
Triazin-2-ylamino) -4 '-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)-
2,2'-stilbenedisulfonic acid, 4- (4-anilino-6-methoxy-1,3,5-triazin-2-ylamino) -4 '-(4,6-dimethoxy-1,3,5-triazine -2-ylamino) -2,2'-stilbene disulfonic acid dipotassium, 4- (4-anilino-6-methoxy-1,3,5-triazin-2-ylamino)-
Potassium hydrogen hydrogen 4 '-(4,6-dimethoxy-1,3,5-triazin-2-ylamino) -2,2'-stilbendisulfonate, 4- (4-anilino-6-methoxy-
1,3,5-triazin-2-ylamino) -4′-
(4,6-dimethoxy-1,3,5-triazine-2-
Sodium hydrogen hydrogen ylamino) -2,2'-stilbene disulfonate, 4- (4-anilino-6-methoxy-1,
3,5-triazin-2-ylamino) -4 ′-(4,6
-Dimethoxy-1,3,5-triazin-2-ylamino) -2,2'-stilbene disulfonate disodium, 4,4'-bis [6- (1-hydroxy-1-methylethylamino) -4- Methoxy-1,3,5-triazin-2-ylamino] -2,2′-stilbendisulfonic acid, 4- (4-chloro-6-methoxy-1,3,5
-Triazin-2-ylamino) -4 '-(4,6-dimethoxy-1,3,5-triazin-2-ylamino)-
2,2'-stilbenedisulfonic acid, 4- (4-chloro-6-methoxy-1,3,5-triazin-2-ylamino) -4 '-(4,6-dimethoxy-1,3,5-triazine -2-ylamino) -2,2'-stilbene disulfonic acid dipotassium, 4- (4-chloro-6-methoxy-1,3,5-triazin-2-ylamino) -4'-
(4,6-dimethoxy-1,3,5-triazine-2-
Potassium hydrogen hydrogen ylamino) -2,2'-stilbendisulfonate, 4- (4-chloro-6-methoxy-1,3,3
5-triazin-2-ylamino) -4 ′-(4,6-
Sodium hydrogen dimethoxy-1,3,5-triazin-2-ylamino) -2,2'-stilbendisulfonate, 4- (4-chloro-6-methoxy-1,3,5-triazin-2-ylamino)- 4 '-(4,6-dimethoxy-1,3,5-triazin-2-ylamino) -2,
Disodium hydrogen 2'-stilbene disulfonate, 4,
4'-bis (4-anilino-6-methoxy-1,3,5
-Triazin-2-ylamino) -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-chloro-6-
(p-sulfophenyloxy) -1,3,5-triazin-2-ylamino] -2,2'sterbendisulfonic acid, 4,4'-bis [4-chloro-6- (p-sulfophenoxy) -1 , 3,5-Triazin-2-ylamino] -2,2'-stilbenedisulfonic acid disodium salt, 4,4'-bis [4-chloro-6- (p-sulfophenoxy) -1,3,5- Triazin-2-ylamino] -2,2'-stilbene disulfonic acid sodium salt
(Monosalt, disalt, trisalt, or tetrasalt), 4,4′-bis [4-
Chloro-6-phenoxy-1,3,5-triazine-2
-Ylamino) -2,2'-stilbene disulfonic acid sodium salt (mono- or di-salt), 4,4'-bis [4-chloro-6-methoxy-1,3,5-triazin-2-ylamino)- 2,2′-stilbene disulfonic acid, 4,
4'-bis (4-chloro-6-methoxy-1,3,5-
Dipotassium triazin-2-ylamino) -2,2'-stilbenedisulfonate, 4,4'-bis (4-chloro-6-methoxy-1,3,5-triazin-2-ylamino) -2,2 ' -Potassium hydrogen stilbene disulfonate, 4,4'-bis (4-chloro-6-methoxy-1,
3,5-triazin-2-ylamino) -2,2′-stilbene disulfonic acid sodium salt (mono or disalt,
4,4'-bis [4- (2-hydroxyethylamino)-
6-phenoxy-1,3,5-triazin-2-ylamino] -2,2′-stilbene disulfonic acid, 4,4 ′
-Bis [4- (2-hydroxyethylamino) -6-methoxy-1,3,5-triazin-2-ylamino]-
2,2'-stilbene disulfonic acid, 4,4'-bis
(4-anilino-6-chloro-1,3,5-triazin-2-ylamino) -2,2′-stilbenedisulfonic acid, 4,4′-bis (4-anilino-6-chloro-1,
3,5-triazin-2-ylamino) -2,2'-stilbene disulfonic acid dipotassium, 4,4'-bis (4
-Anilino-6-chloro-1,3,5-triazine-2
-Ylamino) -2,2'-stilbene disulfonate potassium hydrogen, 4,4'-bis (4-anilino-6-chloro-1,3,5-triazin-2-ylamino) -2,
Sodium 2'-stilbene disulfonate, 4,
4'-bis (4-anilino-6-chloro-1,3,5-
Triazin-2-ylamino) -2,2'-dithorium hydrogensulfonate, 4,4'-bis (4-anilino-6-chloro-1,3,5-triazin-2-ylamino) -2,2 '-Stilbene disulfonic acid potassium sodium salt, 4,4'-bis [4-chloro-6- (p
-Chloroanilino) -1,3,5-triazin-2-ylamino] -2,2'-stilbene disulfonic acid, 4,
4'-bis [4-chloro-6- (p-chloroanilino)-
1,3,5-triazin-2-ylamino] -2,2 ′
-Sodium hydrogen stilbene disulfonate, 4,4'-
Bis [4-chloro-6- (p-chloroanilino) -1,
3,5-triazin-2-ylamino] -2,2'-bisthium hydrogen stilbene disulfonate, 4,4'-bis [4-chloro-6- (2,5-disulfoanilino) -1,
3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-chloro-
6- (2,5-disulfoanilino) -1,3,5-triazin-2-ylamino] -2,2′-stilbene disulfonic acid sodium salt (mono-, di-, tri-, tetra-, penta- or penta-salt) Salt), 4,4'-bis [4-chloro-6- (p-sulfamoylanilino) -1,3,5-triazine-2-
Ilamino] -2,2'-stilbene disulfonic acid disodium salt, 4,4'-bis [4-chloro-6- (m-sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2 ' -Stilbene disulfonic acid, 4,4 '
-Bis [4-chloro-6- (p-sulfoanilino) -1,
3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-chloro-
6- (m-sulfoanilino) -1,3,5-triazine-
2-ylamino] -2,2'-stilbene disulfonic acid potassium salt (mono-, di-, tri- or tetra-salt), 4,4'-
Bis [4-chloro-6- (p-sulfoanilino) -1,
3,5-triazin-2-ylamino] -2,2′-stilbene disulfonic acid potassium salt (monosalt, disalt, trisalt,
Or tetrasalt), 4,4'-bis [4-chloro-6- (2,5
-Disulfoanilino) -1,3,5-triazine-2-
Ilamino] -2,2'-stilbenedisulfonic acid hexapotassium salt, 4,4'-bis [4-chloro-6- (p-sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2 '-Stilbene disulfonic acid sodium salt (mono-, di-, tri- or tetra-salt), 4,4'-bis [4
-Chloro-6- (m-sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid sodium salt (mono-, di-, tri- or tetra-salt), 4 , 4'-bis [4-chloro-6- (2-sulfoethylamino) -1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-
Bis [4-chloro-6- (2-sulfoethylamino)-
1,3,5-triazin-2-ylamino] -2,2 ′
-Stilbene disulfonic acid potassium salt (monosalt, disalt, trisalt or tetrasalt), 4,4'-bis [4-chloro-6- (2-
Sulfoethylamino) -1,3,5-triazine-2-
Ilamino] -2,2′-stilbene disulfonic acid sodium salt (mono-, di-, tri- or tetra-salt), 4,4′-bis [4-chloro-6- (o-toluidino) -1,3,3 5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-chloro-6- (o-
Toluidino) -1,3,5-triazin-2-ylamino] -2,2′-stilbene disulfonic acid dipotassium,
4,4'-bis [4-chloro-6- (o-toluidino)-
1,3,5-triazin-2-ylamino] -2,2 ′
-Potassium hydrogen stilbene disulfonate, 4,4'-bis [4-chloro-6- (o-toluidino) -1,3,5-
Sodium triazin-2-ylamino] -2,2'-stilbendisulfonate, 4,4'-bis [4-chloro-6- (o-toluidino) -1,3,5-triazin-2-ylamino]- Disodium hydrogen 2,2'-stilbene disulfonate, 4,4'-bis [4-chloro-6
-(2-hydroxyethylamino) -1,3,5-triazin-2-ylamino] -2,2'-stilbene disulfonic acid sodium hydrogen salt, 4,4'-bis [4-chloro-
6- (2-hydroxyethylamino) -1,3,5-triazin-2-ylamino] -2,2'-stilbene disulfonate disodium, 4,4'-bis [4-chloro-
6- (2-hydroxyethylamino) -1,3,5-triazin-2-ylamino] -2,2′-stilbendisulfonic acid, 4,4′-bis [4-chloro-6- (7-phenylazo- 8-disulfo-1-naphthylamino)-
1,3,5-triazin-2-ylamino] -2,2 ′
-Stilbene disulfonic acid sodium salt (monosalt, disalt,
Trisalt, tetrasalt, pentasalt, or hexasalt), 4,4′-bis [4-
Chloro-6- (7-phenylazo-8-hydroxy-
2,5-disulfo-1-naphthylamino) -1,3,5
-Triazin-2-ylamino] -2,2'-stilbene disulfonic acid sodium salt (mono-, di-, tri-, tetra-, penta- or hexa-salt), 4,4'-bis [4-chloro-
6- (o-methylanilino) -1,3,5-triazine-
2-ylamino] -2,2'-stilbene disulfonic acid disodium salt, 4,4'-bis (4,6-dichloro-
1,3,5-triazin-2-ylamino) -2,2 ′
-Stilbene disulfonic acid, 4,4'-bis (4,6-
Dichloro-1,3,5-triazin-2-ylamino)
Calcium 2,2'-stilbene disulfonic acid, 4,
Sodium hydrogen 4'-bis (4,6-dichloro-1,3,5-triazin-2-ylamino) stilbene-2,2'-disulfonate, 4,4'-bis [4-morpholino-6- (p -Sulfoanilino) -1,3,5-triazin-2-ylamino] -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-morpholino-6- (2-sulfoethylamino) -1,3 , 5-Triazin-2-ylamino] -2,2'-stilbene disulfonic acid kaurim salt (mono-, di-, tri- or tetra-salt), 4,4'-bis [4
-Morpholino-6- (o-toluidino) -1,3,5-triazin-2-ylamino] -2,2'-stilbendisulfonic acid, 4,4'-bis [4-morpholino-6
(o-Toluidino) -1,3,5-triazin-2-ylamino] -2,2,2'-stilbene disulfonic acid dipotassium, 4,4'-bis [4-morpholino-6- (o-toluidino) -1 , 3,5-Triazin-2-ylamino]
Potassium hydrogen 2,2'-stilbene disulfonate, 4
-(4-chloro-6-methoxy-1,3,5-triazin-2-ylamino) -4 '-(4-methoxy-6-morpholino-1,3,5-triazin-2-ylamino)-
Disodium 2,2'-stillubendisulfonic acid,
4,4'-bis [4-chloro-6-morpholino-1,
3,5-triazin-2-ylamino) -2,2'-stilbenedisulfonic acid, 4,4'-bis [4-chloro-
Sodium hydrogen 6-morpholino-1,3,5-triazin-2-ylamino) -2,2'-stilbendisulfonate, 4,4'-bis [4-chloro-6-morpholino-
1,3,5-triazin-2-ylamino) -2,2 ′
-Disodium stilbene disulfonic acid, 4,4'-bis (4,6-dimorpholino-1,3,5-triazine-
2-ylamino) -2,2′-stilbenedisulfonic acid, 4,4′-bis [4,6-dimorpholino-1,3,3
5-triazin-2-ylamino) -2,2'-stilbene disulfonic acid disodium salt,

Further, the protective layer of the present invention may contain, if necessary, conventional auxiliary additives such as fillers, heat-fusible substances (or lubricants), as long as the objects of the present invention are not impaired.
A surfactant or the like can be contained. Specific examples of the filler and the heat-fusible substance in this case include those similar to those exemplified below in relation to the thermosensitive coloring layer. In addition, the protective layer of the present invention may have a single-layer structure or a laminated structure.

Next, the leuco dye used in the thermosensitive coloring layer of the present invention is used alone or as a mixture of two or more kinds. Such a leuco dye is applied to this kind of thermosensitive recording material. Any of these can be applied, and for example, leuco compounds of dyes such as triphenylmethane, fluoran, phenothiazine, auramine, spiropyran and indolinophthalide are preferably used. Specific examples of such a leuco dye include, for example,
The following are mentioned. 3,3-bis (p
-Dimethylaminophenyl) -phthalide, 3,3-bis
(p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone),
3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis
(p-dibutylaminophenyl) phthalide, 3, cyclohexylamino-6-chlorofluoran 3, dimethylamino-5,7-dimethylfluoran,
3, N-methyl-N-isobutyl-6-methyl-7-anilinofluoran, 3-N-ethyl-N-isoamyl-
6-methyl-7-anilinofluoran, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7
-Methylfluoran, 3-diethylamino-7,8-benzfluoran, 3-diethylamino-6-methyl-7
-Chlorofluorane, 3- (N-ethyl-N-p-tolyl) -6-methyl-7-anilinofluoran, 3- (N
-P-tolyl-N-ethylamino) -6-methyl-7-
Anilinofluoran, 3-pyrrolidino-6-methyl-7
-Anilinofluoran, 2- {N- (3'-trifluoromethylphenyl) amino) -6-diethylaminofluoran, 2- (3,6-bis (diethylamino) -9-
(o-Chloroanilino) xanthyl lactam benzoate), 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluoran, 3-diethylamino-7- (o-chloroanilino) fluoran, 3-dibutylamino-7 -(O-chloroanilino) fluoran, 3-N-methyl-N-amylamino-6-methyl-
7-anilinofluoran 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6
-Methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (2 ', 4'-dimethylanilino) fluoran, 3- (N, N-diethylamino) -5
-Methyl-7- (N, N-dibenzylamino) fluoran, benzoylleucomethylene blue, 6'-chloro-
8'-methoxy-benzoindolino-pyrrospirane,
6'-bromo-3'-methoxy-benzoindolino-pyrrospirane, 3- (2'-hydroxy-4'-dimethylhuminophenyl) -3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2′-hydroxy-
4'-dimethylaminophenyl) -3- (2'-methoxy-5'-nitrophenyl) phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3-
(2′-methoxy-5′-methylphenyl) phthalide,
3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-
Methylphenyl) phthalide, 3-morpholino-7- (N
-Propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-trifluoromethylanilinofluoran, 3-diethylamino-5-chloro-7-
(N-benzyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluoran 3-diethylamino-5-chloro-7- (α-phenylethylamino) fluoran, 3- (N-ethyl-p-toluidino) -7- (α-phenylethylamino) fluoran, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl-7- ( α-phenylethylamino) fluoran, 3-diethylamino-7-piperidinofluoran, 2-chloro-3- (N-methyltoluidino) -7-
(pn-butylanilino) fluoran, 3- (N-methyl-N-isopropylamino) -6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7
-Anilinofluoran, 3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6-dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo- 7-α-naphthylamino-
4'-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluoran, 3-N-ethyl-N-
(2-ethoxypropyl) amino-6-methyl-7-anilinofluoran, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl -7-mesitidino-4 ′, 5′-benzofluoran and the like,

In order to produce the heat-sensitive recording material of the present invention,
When a leuco dye and a developer are bound and supported on a support, various conventional binders can be appropriately used, and specific examples thereof include the following. Polyvinyl alcohol, starch, and derivatives thereof, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose,
Cellulose derivatives such as ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / Maleic anhydride copolymer alkali salt, polyacrylamide,
In addition to water-soluble polymers such as sodium alginate, gelatin and casein, polyvinyl acetate, polyurethane, polyacrylate, polymethacrylate, vinyl chloride /
Emulsions such as vinyl acetate copolymers, ethylene / vinyl acetate copolymers, and latexes such as styrene / butadiene copolymers and styrene / butadiene / acrylic copolymers;

In the heat-sensitive coloring layer of the present invention, auxiliary components commonly used in this type of heat-sensitive recording material, such as fillers and surfactants, may be used together with the leuco dye and the developer, if necessary. A heat-fusible substance (or lubricant) can be used in combination. In this case, the filler
For example, calcium carbonate, silica, zinc oxide, titanium oxide. Aluminum hydroxide, zinc hydroxide, barium sulfate,
In addition to inorganic fine powders such as clay, talc, and surface-treated calcium and silica, organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, and polystyrene resin can be given. Examples of the heat-fusible substance include fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, zinc stearate, aluminum stearate, causium stearate, and palmitic acid. Fatty acid metal salts such as zinc acid and zinc behenate, p-benzylbiphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, β-naphthoic acid phenyl ester, 1-hydroxy -2-naphthoic acid phenyl ester, 1-hydroxy-
2-naphthoic acid methyl ester, diphenyl carbonate, terephthalic acid dibenzyl ester, terephthalic acid dimethyl ester, 1,4-dimethoxynaphthalene, 1,
4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1,2-bis (phenoxy) ethane, 1,
2-bis (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-bis (phenoxy) butane, 1,4-bis (phenoxy) -2-butene, dibenzoylmethane 1,4-bis (phenylthio) butane, 1,4-bis (phenylthio) -2-butene, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) Benzene, p- (2-vinyloxyethoxy) biphenyl, p
-Aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, 1,3-dibenzoyloxypropane, dibenzylcidisulphide,
1,1-diphenylethanol, 1,1-diphenylpropanol, p- (benzyloxy) benzyl alcohol, 1,3-diphenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoylbenzene, etc. Is mentioned.

In the present invention, an undercoat layer may be provided between the support and the thermosensitive coloring layer, if necessary.
Further, another intermediate layer may be provided between the thermosensitive coloring layer and the protective layer, and a back coat layer may be provided on the back surface of the support.

[0015]

EXAMPLES The structure and effects of the present invention will be described below in more detail with reference to examples. The present invention is not limited to these examples. The parts and percentages shown below are based on weight.

[Example 1] [Solution A] 3-dipentylamino-6-methyl-7-anilinofluoran 25 parts Polyvinyl alcohol 10% aqueous solution 25 parts Water 50 parts [Solution B] 2,2-bis (p -Hydroxyphenyl) propane 25 parts Polyvinyl alcohol 10% aqueous solution 12.5 parts Water 62.5 parts Each mixture having the above composition was pulverized by a ball mill so that the average particle size became 2 μm or less. B liquid] was prepared. [Thermal Coating Solution] [Solution A] 20 parts [Solution B] 60 parts Water 20 parts A heat-sensitive coating solution having the above composition is prepared, and the dried coating amount is 2.1 g / m ² on commercially available high-quality paper. To form a thermosensitive coloring layer. Next, the following mixture was stirred to prepare a protective layer liquid [Liquid C], which was coated on the heat-sensitive coloring layer so that the dry adhesion amount was 3.3 g / m ² , dried and calendered. A heat-sensitive recording material was obtained. [Solution C] Water 28 parts Polyvinyl alcohol 10% aqueous solution 50 parts Aluminum hydroxide dispersion (solid content concentration 30%) 15 parts N, N'-toluene-2,4-bis (1-aziridinecarboxamide) (solid content 5 parts zinc stearate dispersion (solids concentration 30%) 2 parts

Example 2 In Example 1, N, N'-hexamethylene-1,6 was used instead of N, N'-toluene-2,4-bis (1-aziridinecarboxamide) in [C solution]. A heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1 except that -bis (1-aziridinecarboxamide) was used.

Comparative Example 1 A polyamide epichlorohydrin resin was used in Example 1 in place of N, N'-toluene-2,4-bis (1-aziridinecarboxamide) in [C Solution]. A heat-sensitive recording material for comparison was obtained in the same manner as in Example 1.

Comparative Example 2 The procedure of Example 1 was repeated, except that benzyl p-hydroxybenzoate was used instead of 2,2-bis (p-hydroxyphenyl) propane in [Solution B]. A heat-sensitive recording material for comparison was obtained.

Comparative Example 3 In Example 1, benzyl p-hydroxybenzoate was used in place of 2,2-bis (p-hydroxyphenyl) propane in [Solution B]. N'-toluene-2,4-bis (1
-Aziridinecarboxamide) instead of N, N'-
A heat-sensitive recording material for comparison was obtained in the same manner as in Example 1 except that hexamethylene-1,6-bis (1-aziridinecarboxamide) was used.

[Example 3] [Example C]
A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the composition was changed to the following. [Liquid C] Water 26 parts Polyvinyl alcohol 10% aqueous solution 50 parts Aluminum hydroxide dispersion (solid content concentration 30%) 15 parts N, N'-toluene-2,4-bis (1-aziridinecarboxamide) dispersion ( 5 parts zinc stearate dispersion (solids concentration 30%) 2 parts 4,4-bis (6-amino-4-chloro-1,3,5-triazin-2-ylamino) -2, Disodium 2'-stilbene disulfonic acid 25% aqueous solution 2 parts

[Example 4] [Example C]
Was carried out except that N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) was used instead of N, N'-toluene-2,4-bis (1-aziridinecarboxamide). A heat-sensitive recording material was obtained in the same manner as in Example 3.

[Comparative Example 4] [Example C]
A thermosensitive recording material was obtained in the same manner as in Example 3, except that a polyamide epichlorohydrin resin was used instead of N, N'-toluene-2,4-bis (1-aziridinecarboxamide).

[Comparative Example 5] In Example 3, [Solution B]
Example 3 except that p-hydroxybenzoic acid was used instead of 2,2-bis (p-hydroxyphenyl) propane
A heat-sensitive recording material was obtained in the same manner as described above.

[Comparative Example 6] [Example B]
P-hydroxybenzoic acid was used in place of 2,2-bis (p-hydroxyphenyl) propane in (C Solution) and N, N'-toluene-2,4-bis (1-aziridinecarboxamide) A thermosensitive recording material was obtained in the same manner as in Example 3 except that a polyamide epichlorohydrin resin was used instead. The following quality evaluation was performed using the heat-sensitive recording materials of Examples and Comparative Examples obtained as described above. Table 1 shows the results. (1) Background Fog The background density of the prepared sample was measured by Macbeth RD-914. (2) Heat resistance Macbeth R
It was measured by D-914. (3) Light resistance Using a thermal printing tester having a thin film head manufactured by Matsushita Electronic Components, head power 0.45 w / dot, line recording time 4 msec / line, scanning line density 8 × 3.85 dots / mm. Printed with a pulse width of 1.0 msec below,
The image density after storage for 24 hours with a fade meter was measured with Macbeth RD-914.

[0026]

[Table 1]

From the above results, the heat-sensitive recording materials of the examples can suppress the occurrence of background fogging due to the use of 2,2-bis (p-hydroxyphenyl) propane as a color developer, It can be seen that the image reliability of the image is also improved.

Table 2 shows the solubility of 2,2-bis (p-hydroxyphenyl) propane in 100 g of a cross-linking agent solution or 100 g of the cross-linking agent used in Examples and Comparative Examples. g) and 100 g of water for the crosslinking agent
The solubility (g) and melting point are shown.

[0029]

[Table 2] (Note) Crosslinking agent A: polyamide epichlorohydrin resin 〃 B: N, N'-toluene-2,4-bis (1-aziridine carboxamide) 〃 C: N, N'-hexamethylene-1,6- Bis (1-aziridinecarboxamide)

[0030]

As described above, even if 2,2-bis (p-hydroxyphenyl) propane is used as a color developer and a cross-linking agent is used in a protective layer, 2,2-bis (p-
By using a specific compound having a specific solubility of (hydroxyphenyl) propane in the crosslinking agent, it is possible to obtain a heat-sensitive recording material in which occurrence of background fog is suppressed. Further, by using an aziridine compound as the cross-linking agent, not only the occurrence of background fogging is suppressed, but also a thermosensitive recording material with less image fading under strong light irradiation can be obtained. Furthermore, by adding not only an aziridine compound but also a stilbene-based fluorescent whitening agent, a heat-sensitive recording material having further improved light fastness, in particular, less discoloration of the background can be obtained.

Claims (5)

[Claims] 1. A thermosensitive coloring layer containing a leuco dye and 2,2-bis (p-hydroxyphenyl) propane as a color developing agent is provided on a support, and a resin and a crosslinking agent are further provided on the coloring layer. In a thermosensitive recording material provided with a protective layer, the solubility of the 2,2-bis (p-hydroxyphenyl) propane in an aqueous solution of a crosslinking agent having a solid concentration of 10% or a dispersion of the crosslinking agent as the crosslinking agent is as follows. The cross-linking agent aqueous solution,
Alternatively, a thermosensitive recording material characterized by using a crosslinking agent in an amount of 0.5 g or less per 100 g of the crosslinking agent dispersion. 2. The heat-sensitive recording material according to claim 1, wherein the crosslinking agent is an aziridine compound. 3. A thermosensitive recording material according to claim 2, wherein said aziridine compound is an aziridine compound having a solubility of not more than 0.05 g in 100 g of water. 4. The heat-sensitive recording material according to claim 3, wherein said aziridine compound is N, N'-toluene-2,4-bis.
(1-aziridinecarboxamide) or N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide). 5. The thermosensitive recording material according to claim 1, wherein the protective layer further contains a stilbene-based fluorescent whitening agent having an absorption peak at a light wavelength of 340 to 400 nm. Recording material.