JP3005078B2 - Thermal recording material - Google Patents

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 having excellent image storability and good heat responsiveness.

[0002]

2. Description of the Related Art A thermosensitive recording material generally comprises a support provided with a thermosensitive recording layer mainly comprising an electron-donating usually colorless or pale-color dye precursor and an electron-accepting developer. By heating with a thermal head, a hot pen, a laser beam or the like, the dye precursor and the color developer react instantaneously to obtain a recorded image. Japanese Patent Publication Nos. 43-4160 and 45-160
It is disclosed in, for example, Japanese Patent Publication No. 14039. Such heat-sensitive recording materials have the advantages of being able to record with a relatively simple device, being easy to maintain, and having no noise.They are measurement recorders, facsimile machines, printers, computer terminals, and labels. It 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 developer has good appearance.
While it has excellent properties such as good feel, high color density, and various color hues, the recorded image area (thermosensitive color area) comes in contact with plastics such as polyvinyl chloride, Preservation of records such as disappearance due to plasticizers and additives contained in plastics, or disappearing easily upon contact with chemicals contained in foods and cosmetics, or fading easily after short sun exposure At the present time, there is a drawback that it is inferior in its properties, and due to this drawback, its use is subject to certain restrictions, and its improvement is strongly desired.

[0004] In view of this point, as a heat-sensitive recording material which reacts when two components are heated to obtain a recorded image having good storability, for example, JP-A-58-38733, JP-A-58-54085, JP-A-58-104959, JP-A-58-149388, JP-A-59-115587
JP-A-59-115888 and U.S. Pat. No. 4,521,793 disclose a heat-sensitive recording material comprising two components consisting of an isocyanate compound and an imino compound. Various sensitizers have been studied in order to improve the thermal response (sensitivity) of a thermosensitive recording material comprising a color developing system of an isocyanate compound and an imino compound. For example, Japanese Patent Application No. 1-340349, Japanese Patent Application No. 1-3433.
No. 75, Japanese Patent Application No. 1-344669, but the thermal responsiveness 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 having excellent image storability.

[0006]

Means for Solving the Problems In order to solve this problem, the present inventors have searched for a sensitizer which improves the thermal response of a thermosensitive recording material using an isocyanate compound and an imino compound. It has been discovered that certain aromatic compounds are particularly effective. 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, an excellent thermal responsiveness that cannot be obtained only with a color former is obtained. Was obtained.

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, and a halogen atom.

In the formula 2, R 'is aryl, aralkyl,
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, a color-forming material having various hues by mixing colors or a multicolor-color-forming material is obtained by using the color-forming material in combination with a color-forming system using an imino compound and an isocyanate compound as a color-forming component.
In the examples in the publication, a color developing system comprising an imino compound and an aldehyde compound of the present invention which develops a green to blue color on a color developing system using an imino compound and an isocyanate compound that develops a dark red color as a coloring agent component. The system system is overcoated to obtain a thermosensitive paper of a color mixture of dark red to black brown. Therefore, the invention described in this publication uses an aldehyde compound as a part of the color-forming material, and the invention relates to a thermosensitive recording paper intended to function as a sensitizer for improving the thermal responsiveness (sensitivity). Is completely different. Further, as specifically shown in the examples, the compounds represented by the general formulas 1 and 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 properties is extremely large.

Specific examples of the compounds represented by Chemical Formula 1 or Chemical Formula 2 used in the present invention include, for example, 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-naphthaldehyde Aldehyde, 2- (4-chlorobenzyloxy) -1
-Naphthaldehyde, 2-benzoyloxy-1-naphthaldehyde, 4-phenoxybenzaldehyde, 4-
Examples include benzyloxybenzaldehyde, 4- (4-bromobenzyloxy) benzaldehyde, 4- (2,4-dichlorobenzyloxy) benzaldehyde, 4-cinnamyloxybenzaldehyde, and 4-cinnamoyloxybenzaldehyde. These heat-fusible substances may be used alone or in admixture of two or more, and 5 to 400% by weight based on the aromatic isocyanate compound,
Preferably it is 10 to 300% by weight. If it is less than 5% by weight, good thermal responsiveness cannot be obtained, and if it is more than 400% by weight, a diluting effect occurs, and similarly good thermal responsiveness cannot be obtained.

The aromatic isocyanate compound used in the present invention refers to a colorless or pale-colored aromatic isocyanate compound or heterocyclic isocyanate compound which is a solid at room temperature, and for example, one or more of the following are 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-dimethylaminophenyl isocyanate,
Tris (4-phenyl isocyanate) thiophosphate and the like. These isocyanate compounds may be used, if necessary, in the form of so-called block isocyanates, which are addition compounds with phenols, lactams, oximes, etc., and diisocyanate dimers,
For example, it may be used in the form of 1-methylbenzene-2,4-diisocyanate dimer and trimer isocyanurate, or used as a polyisocyanate adducted with various polyols and the like. 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 adjacent CＣN), and is a solid at room temperature. It is a colorless or pale compound. Specific examples are shown below. Two or more imino compounds can be used in combination depending on the purpose.

[0015]

Embedded image

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-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-spirodioxolan, 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-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-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-pyradioisoindoline, 1- (cyanobenzoylmethylene) -3-iminoisoindoline, 1- (cyanocarbonamidomethylene) -3-iminoisoindoline, 1- (cyanocarbomethoxymethylene) -3-imino Isoindoline, 1- (cyanocarbethoxymethylene) -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 imide, 3-imino-1-sulfo-4,5,6,7-tetrachlorobenzoimide, 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 imide, 3-imino-1-sulfo-6-methoxybenzoic acid 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. Yes, two or more 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 can be obtained, but it is preferably contained in an amount of 1% by weight or more based on the imino compound. Preferably 5 to 1
000% by weight.

As the support used in the heat-sensitive recording material of the present invention, paper is mainly used. In addition to paper, various nonwoven fabrics, woven fabrics, synthetic resin films, laminated paper, synthetic paper, metal foil, etc. 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 heat-sensitive recording layer, or an intermediate layer may be provided between the heat-sensitive recording layer and the support. In this case, the protective layer and / or the intermediate layer may be composed of two or three or more layers. Further, a back coat layer can 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 each aqueous dispersion obtained by finely pulverizing each color-forming component, a binder and the like, coating the mixture on a support and drying. In this case, for example, each color-forming component may be contained one layer at a time to form a multilayer structure.

The heat-sensitive recording material of the present invention may contain the following heat-fusible substances as additives for further improving the thermal response. Those having a melting point of 60 ° C to 180 ° C are preferred, and those having a melting point of 80 ° C to 140 ° C are particularly preferred. 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, β-naphthol (p-methylbenzyl) ether, 1,4-dimethoxynaphthalene, 1-methoxy-4-benzyloxynaphthalene, N-stearoylurea, -Benzylbiphenyl, metaterphenyl, dimethyl terephthalate and the like.

These heat-fusible substances may be used alone or as a mixture. In order to obtain a sufficient thermal response, the heat-fusible substance is used in an amount of 10 to 3 with respect to the aromatic isocyanate compound.
00% by weight, more preferably 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 described in International Application No. PCT / JP81 / 00300 by the present applicant. More effective.

These compounds include methyl p-aminobenzoate, ethyl p-aminobenzoate, n-propyl p-aminobenzoate, iso-propyl p-aminobenzoate, 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) 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,
-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 trisulfone, 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'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 4,4'-ethylenedianiline, 4,4'-diamino-2,2'-dimethyldibenzyl, 4,4'-diamino-3 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, 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, paraffin oxide, polyethylene, polyethylene oxide, stearic acid amide, caster wax, and dioctyl sulfo succinate. A dispersing agent such as sodium acid, a surfactant, a fluorescent dye, and the like can be contained.

[0028]

The present invention is characterized in that a specific aromatic compound is contained in a heat-sensitive recording material. The aromatic compound has an effect of remarkably improving a hot color development reaction between the aromatic isocyanate compound and the imino compound. Therefore, by containing the aromatic compound in the heat-sensitive recording layer, a heat-sensitive recording material excellent in image preservability comprising an aromatic isocyanate compound and an imino compound,
Excellent thermal responsiveness could be provided.

[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
0g with a ball mill for 24 hours.
10 g of 4 ', 4 "-triisocyanato-2,5-dimethoxytriphenylamine was ground together with 40 g of a 1% aqueous solution of polyvinyl alcohol in a ball mill for 24 hours to obtain a dispersion.
5 g was pulverized in the same manner together with 125 g of a 1% aqueous solution of polyvinyl alcohol to obtain a dispersion. After mixing these three dispersions, 125 g of a 40% aqueous dispersion of calcium carbonate, 50 g of a 30% aqueous dispersion of zinc stearate, 135 g of a 10% aqueous polyvinyl alcohol solution, and 90 g of water were added, and the mixture was sufficiently stirred. I got This coating solution is applied on a base paper having a basis weight of 50 g / m ² so as to obtain an application amount of 5.2 g / m ^{2 as} a solid content, dried, and treated with a super calender to obtain a heat-sensitive recording material. Was.

Examples 2 to 10 Instead of 2-methoxy-1-naphthaldehyde used in Example 1, 2-ethoxy-1-naphthaldehyde (Example 2), 2-propoxy-1-naphthaldehyde (Example 2) Example 3), 2-phenethyloxy-1-naphthaldehyde (Example 4), 2- (2-phenoxyethoxy) -1
-Naphthaldehyde (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 heat-sensitive 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 (color density = thermal response) The heat-sensitive recording materials obtained in Examples 1 to 10 and Comparative Example 1 were
The applied voltage was 1.2 msec and 1.75 msec, respectively, using a thermal facsimile printing tester.
Printing was performed under the condition of 00 volts, 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 preservability) The heat-sensitive recording materials obtained in Examples 1 to 10 and Comparative Example 1 were
Each of them was layered on a vinyl chloride sheet and stored under an atmosphere of 40 ° C. with a load of 300 g / m ² for 24 hours.
In the same manner as in Test 1, the density of the color-developed portion was measured.
To calculate the image residual ratio. 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 developing system of an aromatic isocyanate compound and an imino compound, the combination of the compound according to the present invention provides excellent image storability and thermal response. A heat-sensitive recording material having excellent properties can be obtained.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-187488 (JP, A) JP-A-59-227485 (JP, A) JP-A-61-162383 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B41M 5/28-5/38

Claims (1)

(57) [Claims] 1. A heat-sensitive recording material having a heat-sensitive recording layer containing an aromatic isocyanate compound and an imino compound provided on a support, wherein at least one compound represented by the following general formula 1 or 2 is contained. Characteristic thermal recording material. Embedded image (In the formula, R represents a group having 1 or more and 20 or less carbon atoms, and may have an ether bond, a thioether bond, an ester bond, an unsaturated bond, a carbonyl group, and a halogen atom.) (Wherein 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. )