JPH0524352A - Heat-sensitive recording material - Google Patents

Abstract

PURPOSE:To obtain the above heat-sensitive recording material excellent in image preservability and thermal responsiveness. CONSTITUTION:A heat-sensitive recording material having a heat-sensitive recording layer containing aromatic isocyanate compound and imino compound formed on its supporting body which contains at least one kind of the compound selected from 2-methoxy-1-naphthoaldehyde, 2-phenethyloxy-1-naphthoaldehyde, 4-(4-bromobenzyloxy)benzaldehyde and 4-cinnamyloxybenzaldehyde.

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 which has excellent image storability and good thermal response.

[0002]

2. Description of the Related Art Generally, a heat-sensitive recording material comprises a support and a heat-sensitive recording layer containing an electron-donating, usually colorless or pale-colored dye precursor and an electron-accepting developer as main components. By heating with a thermal head, a heating pen, a laser beam or the like, a dye precursor and a developer react instantaneously to obtain a recorded image. JP-B-43-4160 and JP-B-45-
No. 14039 is disclosed. Such heat-sensitive recording materials have the advantages that they can be recorded with a relatively simple device, are easy to maintain, and do not generate noise.Measurement recorders, facsimiles, printers, computer terminals, labels, etc. , Is used in a wide range of fields such as ticket vending machines.

A heat-sensitive recording material using such an electron-donating colorless dye precursor and an electron-accepting color developer has a good appearance.
While it has excellent properties such as good feel, high color density, and various color hues, the recorded image part (thermosensitive color part) comes in contact with plastic such as polyvinyl chloride. Preservation of records such as disappearance due to plasticizers and additives contained in plastics, easy disappearance upon contact with chemicals contained in foods and cosmetics, or fading easily after exposure to sunlight for a short time It has a drawback that it is inferior in properties, and due to this drawback, its use is subject to certain restrictions, and its improvement is strongly desired.

In view of this point, as a heat-sensitive recording material capable of reacting when two components are heated to obtain a recorded image with good storage stability, for example, JP-A-58-38733 and JP-A-58-54085, JP-A-58-104959, JP-A-58-149388, and JP-A-59-115887.
JP-A-59-115888 and U.S. Pat. No. 4,521,793 disclose heat-sensitive recording materials whose two components are an isocyanate compound and an imino compound. Various sensitizers have been studied in order to improve the thermal responsiveness (sensitivity) of the heat-sensitive recording material comprising a color-forming system of this isocyanate compound and imino compound. For example, Japanese Patent Application Nos. 1-340349 and 1-3433
No. 75, Japanese Patent Application No. 1-344669, but the thermal response is still insufficient.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to improve the thermal response (sensitivity) of a heat-sensitive recording material comprising an isocyanate compound and an imino compound which are excellent in image storability.

[0006]

In order to solve this problem, the present inventors have searched for a sensitizer which improves the thermal response of a thermal recording material using an isocyanate compound and an imino compound. It has been found that the effect is particularly great with a specific aromatic compound. That is, in a heat-sensitive recording material containing an aromatic isocyanate compound and an imino compound, by containing at least one compound represented by the general formula 1 or 2, the excellent thermal response which cannot be obtained only by the color former is obtained. It was possible to obtain a heat-sensitive recording material provided with.

In Formula 1, R represents a group having 1 to 20 carbon atoms and may have an ether bond, a thioether bond, an ester bond, an unsaturated bond, a carbonyl group or a halogen atom.

In formula 2, R'is aryl, aralkyl,
It represents a cinnamyl or cinnamoyl group and may have a substituent selected from alkyl, alkoxy and halogen on the aromatic ring of each group.

JP-A-59-227485 discloses a color forming material comprising an imino compound and one or more compounds selected from aromatic aldehydes and paraformaldehyde. In this publication, the color forming material is used in combination with a color forming system containing an imino compound and an isocyanate compound as a color forming agent component to obtain a color forming material having various hues due to color mixing or a multicolor coloring material.
In the examples of the publication, a color-forming system comprising an imino compound and an aldehyde compound as a color-forming agent component which develops a green to green color on a color-forming system comprising an imino compound and a isocyanate compound as a color-forming component component which develop a dark red color. The system is overcoated to obtain a thermal paper with a mixed color of dark red to black brown. Therefore, the invention described in the publication uses an aldehyde compound as a part of a color-forming material, and a heat-sensitive recording paper aiming at the function as a sensitizer for improving the thermal response (sensitivity) of the present invention. Is completely different. Further, as will be specifically shown in Examples, the compounds represented by the general formula 1 or 2 according to the present invention are more thermally responsive than the aromatic aldehyde compounds exemplified in JP-A-59-227485. The effect of improving the sex is extremely large.

Specific examples of the compound represented by Chemical Formula 1 or Chemical Formula 2 used in the present invention include the following, but the present invention is not limited thereto.

2-methoxy-1-naphthaldehyde, 1
-Methoxy-2-naphthaldehyde, 2-ethoxy-1
-Naphthaldehyde, 2-propoxy-1-naphthaldehyde, 2-phenethyloxy-1-naphthaldehyde, 2- (2-phenoxyethoxy) -1-naphthaldehyde, 2- (4-methylbenzyloxy) -1-naphtho Aldehyde, 2- (4-chlorobenzyloxy) -1
-Naphthoaldehyde, 2-benzoyloxy-1-naphthaldehyde, 4-phenoxybenzaldehyde, 4-
Benzyloxybenzaldehyde, 4- (4-bromobenzyloxy) benzaldehyde, 4- (2,4-dichlorobenzyloxy) benzaldehyde, 4-cinnamyloxybenzaldehyde, 4-cinnamoyloxybenzaldehyde and the like can be mentioned. These heat-fusible substances may be used alone or in combination of two or more, and may be used in an amount of 5 to 400% by weight based on the aromatic isocyanate compound.
It is preferably 10 to 300% by weight. If it is 5% by weight or less, good thermal response cannot be obtained, and if it is 400% by weight or more, a dilution effect occurs, and similarly good thermal response cannot be obtained.

The aromatic isocyanate compound used in the present invention refers to a colorless or light-colored aromatic isocyanate compound or a heterocyclic isocyanate compound which is solid at room temperature, and for example, one or more of the following may be used.

2,6-dichlorophenyl isocyanate, p-chlorophenyl isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1,3-dimethylbenzene-4,6-diisocyanate, 1,4-dimethylbenzene-2,5-diisocyanate, 1-methoxybenzene-2,4-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
-Diisocyanate, azobenzene-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, naphthalene-
2,6-diisocyanate, naphthalene-2,7-diisocyanate, 3,3'-dimethylbiphenyl-4,
4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenyldimethylmethane-4,4'-diisocyanate, benzophenone-
3,3'-diisocyanate, fluorene-2,7-diisocyanate, anthraquinone-2,6-diisocyanate, 9-ethylcarbazole-3,6-diisocyanate, pyrene-3,8-di Isocyanate, naphthalene-1,3,7-triisocyanate, biphenyl-
2,4,4'-triisocyanate, 4,4 ', 4 "-
Triisocyanate-2,5-dimethoxytriphenylamine, p-dimethylaminophenylisocyanate,
Examples include tris (4-phenylisocyanate) thiophosphate. These isocyanate compounds may be used in the form of so-called block isocyanate, which is an addition compound with phenols, lactams, oximes, etc., if necessary, and a diisocyanate dimer,
For example, it may be used in the form of isocyanurate, which is a dimer or trimer of 1-methylbenzene-2,4-diisocyanate, or used as a polyisocyanate adducted with various polyols. Is also possible.

The imino compound used in the present invention is a compound represented by the general formula 3 (φ is an aromatic compound residue capable of forming a conjugated system with an adjacent C═N) and is a solid at room temperature. It is a colorless or pale compound. A specific example is shown below. It is also possible to use two or more kinds of imino compounds in combination depending on the purpose.

[0015]

[Chemical 3]

3-iminoisoindoline-1-one, 3
-Imino-4,5,6,7-tetrachloroisoindoline-1-one, 3-imino-4,5,6,7-tetrabromoisoindoline-1-one, 3-imino-4,5,5
6,7-Tetrafluoroisoindoline-1-one, 3
-Imino-5,6-dichloroisoindoline-1-one, 3-imino-4,5,7-trichloro-6-methoxyisoindoline-1-one, 3-imino-4,5,7
-Trichloro-6-methoxyisoindoline-1-one, 3-imino-4,5,7-trichloro-6-methylmercaptoisoindoline-1-one, 3-imino-6
-Nitroisoindoline-1-one, 3-iminoisoindoline-1-spirodioxolane, 1,1-dimethoxy-3-iminoisoindoline, 1,1-diethoxy-
3-imino-4,5,6,7-tetrachloroisoindoline, 1-ethoxy-3-iminoisoindoline, 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-imino naphthalic acid imide, 1-imino diphenic acid imide, 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-iminosoindoline, 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-Pyradiisoindoline, 1- (cyanobenzoylmethylene) -3-iminoisoindoline, 1- (cyanocarbonamidomethylene) -3-iminoisoindoline, 1- (cyanocarbomethoxymethylene) -3-imino Isoindoline, 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 ′)-carbamoyl Methylene) -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-[(cyanobenz Imidazolyl-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-pyradiiso Indoline, 1-[(1'-methyl-3'-n-butyl) -barbituric acid-5 ']-3-
Iminoisoindoline.

3-imino-1-sulfobenzoic acid imide,
3-imino-1-sulfo-6-chlorobenzoic acid imide,
3-imino-1-sulfo-5,6-dichlorobenzoic acid imide, 3-imino-1-sulfo-4,5,6,7-tetrachlorobenzoic acid imide, 3-imino-1-sulfo-
4,5,6,7-Tetrabromobenzoic acid imide, 3-imino-1-sulfo-4,5,6,7-tetrafluorobenzoic acid imide, 3-imino-1-sulfo-6-nitrobenzoic acid imide, 3-imino-1-sulfo-6-methoxybenzoimide, 3-imino-1-sulfo-4,5,7
-Trichloro-6-methylmercaptobenzoic acid imide,
3-imino-1-sulfonaphthoic acid imide, 3-imino-1-sulfo-5-bromonaphthoic acid imide, 3-imino-2-methyl-4,5,6,7-tetrachloroisoindoline-1-one Therefore, two or more kinds of imino compounds can be used in combination depending on the purpose.

The amount of the aromatic isocyanate compound used is not particularly limited as long as it reacts with the imino compound and a color image is obtained, but it is preferably contained in an amount of 1% by weight or more based on the imino compound. Preferably 5 to 1
It is 000% by weight.

Paper is mainly used as a support for the heat-sensitive recording material of the present invention. In addition to paper, various non-woven fabrics, woven fabrics, synthetic resin films, laminated papers, synthetic papers, metal foils and the like, or these A composite sheet obtained by combining the above can be arbitrarily used according to the purpose.

The layer structure of the heat-sensitive recording layer may be only the heat-sensitive recording layer. If necessary, a protective layer may be provided on the thermosensitive recording layer, or an intermediate layer may be provided between the thermosensitive recording layer and the support. In this case, the protective layer and / or the intermediate layer may be composed of a plurality of layers of 2 layers or 3 layers or more. Further, a back coat layer may be provided on the surface of the support opposite to the surface on which the heat-sensitive recording layer is provided for the purpose of preventing curling and charging.

The heat-sensitive recording layer can be obtained by mixing the respective aqueous dispersions obtained by finely pulverizing the respective color-forming components with a binder and the like, coating on a support and drying. In this case, for example, each color-forming component may be contained in one layer to form a multilayer structure.

The heat-sensitive recording material of the present invention may contain a heat-fusible substance as described below as an additive for further improving its thermal response. Those having a melting point of 60 ° C. to 180 ° C. are preferable, and those having a melting point of 80 ° C. to 140 ° C. are particularly preferable. For example, benzyl p-benzyloxybenzoate, stearic acid amide, palmitic acid amide, N-methylol stearic acid amide, β-
Naphthyl benzyl ether, N-stearyl urea,
N, N′-distearylurea, β-naphthoic acid phenyl ester, β-naphthol (p-methylbenzyl) ether, 1,4-dimethoxynaphthalene, 1-methoxy-4-benzyloxynaphthalene, N-stearoylurea, 4 -Benzyl biphenyl, metaterphenyl, dimethyl terephthalate, etc. are mentioned.

These heat-fusible substances may be used alone or as a mixture, and in order to obtain a sufficient heat response, the heat-fusible substance is added in an amount of 10 to 3 with respect to the aromatic isocyanate compound.
It is preferable to use 100% by weight, and further 20 to 25
It is more preferable to use 0% by weight.

Further, the heat-sensitive recording material of the present invention may contain an aniline derivative having at least one amino group, which is shown in the international application PCT / JP81 / 00300 by the applicant of the present invention. More effective.

These compounds include methyl p-aminobenzoate, ethyl p-aminobenzoate, n-propyl p-aminobenzoate, iso-propyl p-aminobenzoate and butyl p-aminobenzoate. Dodecyl p-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) carrubamoyl] 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-aminophenoxy) phenyl] sulfone,
Bis [3-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-Sort Lysine Sulfone, 2,4'-diaminobiphenyl, 2,2'-diaminobiphenyl, 4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diaminobiphenyl, 3,3'-dichloro- 4,4'-diaminobiphenyl, 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-aminophenyl) 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, and the like.

Further, in the heat-sensitive recording layer, pigments such as diatomaceous earth, talc, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, titanium oxide, zinc oxide, silicon oxide, aluminum hydroxide, urea-formalin resin, etc. For the purpose of preventing head abrasion, sticking, etc., higher fatty acid metal salts such as zinc stearate and calcium stearate, waxes such as paraffin, oxidized paraffin, polyethylene, polyethylene oxide, stearic acid amide and castor wax, and dioctylsulfosuccinic acid. A dispersant such as sodium acid salt, a surfactant, a fluorescent dye, or the like may be contained.

[0028]

The present invention is characterized in that the heat-sensitive recording material contains a specific aromatic compound. This aromatic compound has the effect of significantly improving the color development reaction of the aromatic isocyanate compound and the imino compound when heated. Therefore, by containing the aromatic compound in the heat-sensitive recording layer, a heat-sensitive recording material comprising an aromatic isocyanate compound and an imino compound and having excellent image storability,
It was possible to impart excellent thermal response.

[0029]

The present invention will be described in more detail with reference to the following examples.

Example 1 15 g of 1,3-diimino-4,5,6,7-tetrachloroisoindoline was added to a 1% aqueous solution of polyvinyl alcohol 6
Grind with 0g in a ball mill for 24 hours, and
10 g of 4 ', 4 "-triisocyanato-2,5-dimethoxytriphenylamine was crushed with 40 g of a 1% aqueous solution of polyvinyl alcohol in a ball mill for 24 hours to obtain a dispersion liquid. 2-Methoxy-1-naphthaldehyde 2
5 g was similarly pulverized together with 125 g of a 1% polyvinyl alcohol aqueous solution to obtain a dispersion liquid. After mixing these three types of dispersions, 125 g of 40% aqueous dispersion of calcium carbonate, 50 g of 30% aqueous dispersion of zinc stearate, 135 g of 10% polyvinyl alcohol aqueous solution, and 90 g of water were added and thoroughly stirred to obtain a coating liquid. Got This coating solution was coated on a base paper having a basis weight of 50 g / m ² so that a solid coating amount of 5.2 g / m ² was obtained, dried and then treated with a super calendar to obtain a heat-sensitive recording material. It was

Examples 2 to 10 Instead of 2-methoxy-1-naphthaldehyde used in Example 1, 2-ethoxy-1-naphthaldehyde (Example 2) and 2-propoxy-1-naphthaldehyde (Example) Example 3), 2-phenethyloxy-1-naphthaldehyde (Example 4), 2- (2-phenoxyethoxy) -1
-Naphthoaldehyde (Example 5), 2- (4-methylbenzyloxy) -1-naphthaldehyde (Example 6),
4- (4-bromobenzyloxy) benzaldehyde (Example 7), 4- (2,4-dichlorobenzyloxy) benzaldehyde (Example 8), 4- (cinnamyloxy) benzaldehyde (Example 9), 4- A thermosensitive recording material was obtained in the same manner as in Example 1 except that (cinnamoyloxy) benzaldehyde (Example 10) was used.

Comparative Example 1 A thermosensitive recording material was obtained in the same manner as in Example 1 except that the 2-methoxy-1-naphthaldehyde used in Example 1 was not used.

Test 1 (coloring density = thermoresponsiveness) The thermal recording materials obtained in Examples 1 to 10 and Comparative Example 1 were
An applied voltage of 22 ms and an applied voltage of 2.75 ms were applied using a thermal facsimile printing tester, respectively.
Printing was performed under the condition of 00 V, and the density of the obtained color image was measured using a densitometer Macbeth RD918. The results are shown in Table 1.

Test 2 (Plasticizer resistance = image storability) The thermal recording materials obtained in Examples 1 to 10 and Comparative Example 1 were
After overlaying each with a vinyl chloride sheet and applying a load of 300 g / m ² and storing in an atmosphere of 40 ° C. for 24 hours,
In the same manner as in Test 1, measure the density of the color development area and
The image residual rate was calculated by. The results are shown in Table 1.

[0035]

[Equation 1]

[0036]

[Table 1]

[0037]

As shown in Table 1, in a heat-sensitive recording material comprising a color-forming system of an aromatic isocyanate compound and an imino compound, by combining the compound according to the present invention, excellent image storability and thermal response are obtained. A heat-sensitive recording material having excellent properties can be obtained.

Claims (1)

Claim: What is claimed is: 1. A thermosensitive recording material comprising a support and a thermosensitive recording layer containing an aromatic isocyanate compound and an imino compound, wherein a compound represented by the following general formula 1 or 2 is used. A heat-sensitive recording material containing at least one kind. [Chemical 1] (In the formula, R represents a group having 1 to 20 carbon atoms, and may have an ether bond, a thioether bond, an ester bond, an unsaturated bond, a carbonyl group, or a halogen atom.) (In the formula, R ′ represents an aryl, aralkyl, cinnamyl or cinnamoyl group, and on the aromatic ring of each group,
It may have a substituent selected from alkyl, alkoxy and halogen. )