JP2000033777A - Thermosensible recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light-fastness, the stability of a recorded image, chemical resistance, and transparency by forming a recording layer through application of organic solvent coating liquid containing a coloring agent expressed by a specific formula. SOLUTION: The thermosensible recording layer is formed by applying organic solvent coating liquid containing a coloring agent expressed in formula (in the formula, R1 is a naphthyl group being unsubstituted or replaced by an alkyl group, a halogen group, or a lower alkoxyl). The thermosensible body contains at least one kind of methylethyl ketone, ethyl acetate, and 1,3- dioxolane. In the thermosensible recording body of one layer or more including a support body provided with a thermosensible layer containing a coloring agent and basic paint on a transparent or opaque support body, a specific material is employed as a coloring material, and a coating method using organic solvent coating liquid is used, thereby obtaining a thermosensible recording body being excellent in the stability of a recorded image. Also, by allowing a UV ray absorbing agent to be contained in at least one layer of layers constituting the thermosensible recording body, light-fastness is enhanced.

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 utilizing a color-forming reaction between a colorless or light-colored basic dye and a color former, and more particularly to a heat-sensitive recording material which is excellent in light resistance, stability of recorded images and chemical resistance. It relates to a thermosensitive recording medium.

[0002]

2. Description of the Related Art A thermosensitive recording medium which uses a color reaction between a colorless or light-colored basic dye and an organic or inorganic colorant to contact both coloring materials by heat to obtain a recorded image is often used. Are known. Such a thermosensitive recording medium is relatively inexpensive, and its recording equipment is compact and easy to maintain, so that it is used not only as a recording medium for facsimile machines and various computers but also in a wide range of fields. With the expansion of applications, thermosensitive recording media are also used for printing halftone images for video, medical, drafting, and the like.

[0003] The coloring portion of a thermal recording medium tends to be erased when it receives heat, humidity, and the like, and various techniques have been disclosed to suppress the erasing. For example, JP-A-59-11
JP-A No. 4096, JP-A-59-167292, and JP-A-60-78782.
A compound in which a specific phenolic compound is blended in a thermosensitive coloring layer, a compound in which a specific epoxy compound is blended in a thermosensitive coloring layer as disclosed in JP-A-4-28589, and JP-A-6-227129. In which a specific phosphorus compound as described in JP-A-6-234273 is incorporated into a thermosensitive coloring layer.
A compound in which an arylsulfonic acid amide is blended in a thermosensitive coloring layer is known.

[0004] However, none of these methods can suppress erasing in a halftone portion, which is important for video and medical use, at a satisfactory level. Further, with the expansion of applications, the use of the thermosensitive recording medium in which the transparency and light transmittance are required is increasing in the fields of medical use, drafting, and the like. In order to increase the transparency of the heat-sensitive recording layer of the heat-sensitive recording film, there is a method in which the particulate material added to the recording layer, the protective layer, or the like is made finer or the ratio of the adhesive is increased. At present, it is not enough.

Japanese Patent Application Laid-Open Nos. 59-106992 and 9-66673 disclose a method in which a heat-sensitive recording layer is formed by a solvent coating method and / or a vapor deposition method. , The production cost becomes a problem. Also, JP-A-4-239688 describes a method of applying a dye and a colorant with a combination of a solvent system and an aqueous system, but the transparency is insufficient or
There was a disadvantage that the sensitivity was poor.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method which can be easily produced by a conventional coating method and has excellent light resistance, stability of recorded images and chemical resistance.
It is another object of the present invention to provide a thermosensitive recording medium having excellent transparency of a coating layer as required.

[0007]

According to the present invention, there is provided a thermosensitive recording medium comprising a support and a thermosensitive recording layer containing a colorant and a basic dye, wherein the thermosensitive recording layer is represented by the following general formula (1). A heat-sensitive recording material formed by applying an organic solvent-based coating liquid containing a coloring agent represented by the formula (1).

Embedded image (R ₁ represents one group selected from a phenyl group or a naphthyl group which is unsubstituted or substituted by an alkyl group, a halogen group, or a lower alkoxy group, and Y represents the following chemical formula:

Embedded image Represents one group selected from divalent groups represented by
n represents an integer of 11 to 30. The present invention relates to the general formula (1), wherein R ₁ is unsubstituted;
Or a naphthyl group substituted by an alkyl group, a halogen group or a lower alkoxy group. The present invention relates to a thermosensitive recording medium containing at least one of methyl ethyl ketone, ethyl acetate and 1,3-dioxolan in an organic solvent-based coating liquid. The present invention relates to a JIS in a heat-sensitive recording layer.
In the measurement by the melting point and melting range measurement method specified in K0064, after the end point of the melting, the sample was left for 5 minutes, and the capillary containing the sample was allowed to stand in an atmosphere of 20 ± 1 ° C. for 48 hours within 10 seconds. Also, the present invention relates to a thermosensitive recording medium containing a hindered phenol compound which does not cause crystallization as defined in JIS K0211. The present invention relates to a thermosensitive recording medium containing a binder having a glass transition temperature of 20 ° C. or more in a thermosensitive recording layer. The present invention relates to a thermosensitive recording medium further provided with a protective layer on the thermosensitive recording layer. The present invention
The present invention relates to a heat-sensitive recording medium in which an intermediate layer is provided between a heat-sensitive recording layer and a protective layer, and the intermediate layer contains a polyester resin. The present invention relates to a thermosensitive recording medium in which at least one of the layers constituting the thermosensitive recording medium contains an ultraviolet absorbent. The present invention relates to a thermosensitive recording medium containing an ultraviolet absorber in a microcapsule.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a heat-sensitive recording material comprising at least two layers including a support, wherein a heat-sensitive recording layer containing a colorant and a basic dye is provided on a transparent or opaque support. By using a specific material as a coloring agent and using a coating method using an organic solvent-based coating liquid as a method for forming a heat-sensitive recording layer, it has been found that a heat-sensitive recording material having excellent stability of a recorded image can be obtained. Further, by incorporating an ultraviolet absorber into at least one of the layers constituting the heat-sensitive recording medium, light resistance and stability of a recorded image are excellent. In particular, the ultraviolet absorber is microencapsulated to constitute a heat-sensitive recording medium. The inventors have found that a thermosensitive recording medium having excellent chemical resistance and transparency can be obtained by incorporating it in at least one of the layers, thereby completing the present invention.

The heat-sensitive recording material of the present invention is a heat-sensitive recording material having a heat-sensitive recording layer containing a colorant and a basic dye on a support, represented by the following general formula (1). Wherein the heat-sensitive recording layer is formed by coating using an organic solvent-based coating liquid.

[0010]

Embedded image

(R ₁ represents an unsubstituted group or a group selected from a phenyl group or a naphthyl group substituted by an alkyl group, a halogen group, a lower alkoxy group, and Y represents the following chemical formula:

[0012]

Embedded image

Represents one group selected from divalent groups represented by the following formulas, and n represents an integer of 11 to 30. When n is less than 11 in the general formula (1), the solubility of the compound of the general formula (1) in a solvent is increased, and the degree of coloring of the coated surface is not preferred. On the other hand, when n exceeds 30, the color density decreases.

In the compound of the formula (1), R ₁ is unsubstituted or a phenyl group or a naphthyl group substituted by an alkyl group, a halogen group or a lower alkoxy group. Preferred examples include the following groups. Can be.

[0015]

Embedded image

Of these groups, naphthyl group compounds, which are unsubstituted or substituted by an alkyl group, a halogen group, or a lower alkoxy group, balance the fog of the ground portion after coating with the sensitivity. Furthermore, the stability of the recorded image is excellent, and it can be preferably used. Specific examples of the aromatic compound used as a colorant in the thermosensitive recording medium of the present invention include the following chemical formula:

[0017]

Embedded image

Examples of the compounds represented by These compounds may be used alone or in combination of two or more. In the present invention, an organic solvent-based coating liquid is applied to a support as a method for forming a heat-sensitive recording layer. Examples of the organic solvent for dissolving and dispersing the material and adhesive constituting the heat-sensitive layer include hydrocarbons and halogenated compounds. Hydrocarbons, alcohols, ethers, acetals, ketones, esters and the like are used alone or as a mixed organic solvent.

Specific examples of the hydrocarbons include, for example, benzene, toluene, xylene, hexane, cyclohexane, methylcyclohexane, cyclopentane, and petroleum ether. Specific examples of the halogenated hydrocarbons include:
For example, chloroform, methylene chloride, carbon tetrachloride, chlorobenzene, dichlorobenzene and the like, as specific examples of alcohols, for example, methanol, ethanol, propanol, isopropanol, butanol and the like, specific examples of ethers, for example, ethyl ether, Isopropyl ether, 1,3-dioxolane and the like, specific examples of the acetal, for example, diethyl acetal and the like,
Specific examples of ketones include, for example, acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone. Specific examples of the esters include, for example, ethyl acetate, methyl acetate, methyl propionate, and the like. However, the present invention is not limited to this. These solvents may be used alone or as a mixture of two or more. Furthermore, among these solvents, methyl ethyl ketone, ethyl acetate,
When 1,3-dioxolane or the like is contained in an organic solvent-based solution, an organic solvent solution which is excellent in background fog and which is excellent in terms of handling and the like can be obtained.

The strength of the heat-sensitive layer can be improved by including an adhesive in the heat-sensitive layer. The adhesive used in the heat-sensitive layer is not particularly limited as long as it is a resin soluble in an organic solvent, but a thermoplastic resin is particularly preferably used, and a thermoplastic resin soluble in the organic solvent as described above. Are more preferably used. Specific examples thereof include, for example, acrylic resins, polystyrenes, poly-α-methylstyrenes, vinyl chloride resins, vinyl chloride / vinyl acetate copolymers, ethylene / vinyl acetate copolymers, and polyvinyl acetal resins. And the like, and cellulose-based polymers such as nitrocellulose, polyester-based resins, polyurethane-based resins, cumarone-based resins, nylon-based resins, and the like, but of course, are not limited thereto, and two or more resins may be used in combination. Is also possible. Among these resins, those having a glass transition temperature of 20 ° C. or more can be preferably used because the stability of the recorded image is improved, and the resin is selected from a polyvinyl acetal resin and a polyester resin. If you use at least one,
Since more excellent stability of the recorded image can be obtained and further excellent mechanical strength of the heat-sensitive recording layer can be obtained, it can be more preferably used.

The amount of the adhesive to be used is not particularly limited, but is not more than 0.1% based on the total solids of the coating solution.
It is desirable to adjust the amount in the range of 5 to 90% by weight, preferably 1 to 60% by weight.

As the colorless or light-colored basic dye used in the present invention, various known dyes can be used. Specific examples thereof include, for example, 3,3-bis (p-
Dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-methylphenyl)
Blue-coloring dyes such as -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide and 3-diethylamino-7-dibenzylamino-benzo [a] fluoran: 3
Green coloring such as-(N-ethyl-N-p-tolyl) amino-7-N-methylanilinofluoran, 3-diethylamino-7-anilinofluoran, 3-diethylamino-7-dibenzylaminofluoran, etc. Sex dyes: 3,6-bis (diethylamino) fluoran-γ-anilinolactam, 3-cyclohexylamino-6-chlorofluoran, 3-dibutylamino-6-methyl-7-bromofluoran, 3-diethylamino-7 -Methylfluoran,
3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane, rhodamine (o-chloroanilino) lactam, rhodamine (p-chloroanilino) lactam, 3-diethylamino-7,8-benzofuran Oran, 3- (N-ethyl-p-
Toluidino) -7-methylfluoran, 3-diethylamino-6,8-dimethylfluoran, 3- (N-ethyl-N-isoamyl) amino-benzo [a] fluoran,
3,3'-bis (1-n-butyl-2-methylindol-3-yl) phthalide, 2- (4-dodecyloxy-
Red-coloring dyes such as 3-methoxystyryl) quinoline: 3
-(N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino -6-methyl-7-anilinofluoran, 3-di (n-butyl) amino-6-methyl-7-anilinofluoran, 3-di (n-pentyl)
Amino-6-methyl-7-anilinofluoran, 3-diethylamino-7- (o-chlorophenylamino) fluoran, 3-di (n-butyl) amino-7- (o-chlorophenylamino) fluoran, 3-diethylamino −
7- (o-fluorophenylamino) fluoran, 3-
Di (n-butyl) amino-7- (o-fluorophenylamino) fluoran, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluoran, 3- (N
-Ethyl-p-toluidino) -6-methyl-7- (p-
Toluidino) fluoran, 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluoran, 3-diethylamino-6-chloro-7-
Anilinofluoran, 3- (N-methyl-NNn-propylamino) -6-methyl-7-anilinofluoran,
3-dimethylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-m-toluidinofluoran, 3- (Nn-hexyl-N-ethyl) amino- 6-methyl-7-anilinofluoran, 3
-(N-ethyl-N-isobutyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-6
Methyl-7-p-ethoxyanilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-
Piperidino-6-methyl-7-anilinofluoran,
2,2-bis {4- [6 '-(N-cyclohexyl-N
-Methylamino) -3'-methylspiro [phthalide-
Black coloring dyes such as 3,9'-xanthen-2'-yl-amino] phenyl} propane and 3-diethylamino-7- (3'-trifluoromethylphenyl) aminofluoran: 3,3-bis [1 -(4-methoxyphenyl)
-1- (4-dimethylaminophenyl) ethylene-2-
Yl] -4,5,6,7-tetrachlorophthalide, 3,
3-bis [1- (4-methoxyphenyl) -1- (4-
Pyrrolidinophenyl) ethylene-2-yl] -4,5
6,7-tetrachlorophthalide, 3,3-bis [1,1
-Bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide, 3-p
-(P-dimethylaminoanilino) anilino-6-methyl-7-chlorofluoran, 3-p- (p-chloroanilino) anilino-6-methyl-7-chlorofluoran,
2,4-dimethyl-6 '-{[4- (N, N-dimethylamino) phenyl] amino} -spiro [isobenzofuran-1 (3H), 9'-[9H] xanthen] -3-one, , 6-Bis (dimethylamino) fluorene-9-
Spiro-3 '-(6'-dimethylamino) phthalide, 3
Dyes having an absorption wavelength in the near infrared region, such as-{1,1-bis (1-ethyl-2-methylindol-3-yl)}-3-p-diethylaminophenylphthalide. Of course, the present invention is not limited to these, and two or more of them can be used in combination as needed.

The heat-sensitive layer has the following properties:
Pigments, crosslinking agents, sensitizers, storability improvers, ultraviolet absorbers, light stabilizers and the like exemplified below can be contained in order to improve the storability. As the pigment, kaolin,
Clay, calcium carbonate, aluminum hydroxide, aluminum oxide, calcined clay, calcined kaolin, titanium oxide,
Examples include inorganic pigments such as talc, zinc oxide, and silica, and organic pigments such as styrene microballs, nylon powder, polyethylene powder, urea formalin resin filler, raw starch particles, silicon powder, and acrylic resin. Of course, the present invention is not limited to these, and two or more of them can be used in combination as needed.

Examples of the crosslinking agent include dialdehyde compounds such as glyoxal and dialdehyde starch; polyamine compounds such as polyethyleneimine; epoxy compounds;
Use of polyamide resins, melamine resins, diglycidyl compounds such as glycerin diglycidyl ether, dimethylol urea compounds, aziridine compounds, isocyanate compounds, and inorganic compounds such as ammonium persulfate, ferric chloride, magnesium chloride, and zirconium carbonate compounds. Can be. Of course, the present invention is not limited to these, and two or more of them can be used in combination as needed.

Specific examples of the sensitizer include, for example, stearic acid amide, methoxycarbonyl-N-stearic acid benzamide, N-benzoylstearic acid amide, N-
Eicosanoic acid amide, ethylenebisstearic acid amide, behenic acid amide, methylenebisstearic acid amide, N-methylolstearic acid amide, dibenzyl terephthalate, dimethyl terephthalate, dioctyl terephthalate, benzyl p-benzyloxybenzoate, 1-hydroxy Phenyl-2-naphthoate, 2-naphthylbenzyl ether, m-terphenyl, dibenzyl oxalate, di-p-methylbenzyl oxalate, di-p-chlorobenzyl oxalate, p-benzylbiphenyl, p-
Tolylbiphenyl ether, di (p-methoxyphenoxyethyl) ether, 1,2-di (3-methylphenoxy) ethane, 1,2-di (4-methylphenoxy) ethane, 1,2-di (4-methoxyphenoxy) ) Ethane,
1,2-di (4-chlorophenoxy) ethane, 1,2-
Diphenoxyethane, 1- (4-methoxyphenoxy)
-2- (3-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, p-acetotoluidide, p-acetophenethidide, N-acetoacetyl-p-toluidine, di ( β
-Biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-isopropylphenyl-2
-Phenylethane and the like. Of course, the present invention is not limited to these, and two or more of them can be used as needed.

As the preservability improver, for example, 2,2'-
Methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-
tert-butylphenol), 2,2′-ethylidenebis (4,6-di-tert-butylphenol),
4,4'-thiobis (2-methyl-6-tert-butylphenol), 4,4'-butylidenebis (6-te
rt-butyl-m-cresol), 1- [α-methyl-
α- (4′-hydroxyphenyl) ethyl] -4-
[Α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene, 1,1,3-tris (2-methyl-4-
(Hydroxy-5-cyclohexylphenyl) butane,
1,1,3-tris (2-methyl-4-hydroxy-5
-Tert-butylphenyl) butane, 4,4'-thiobis (3-methylphenol), 4,4'-dihydroxy-3,3 ', 5,5'-tetrabromodiphenylsulfone, 4,4'-dihydroxy- 3,3 ', 5,5'-
Tetramethyldiphenyl sulfone, 2,2-bis (4-
(Hydroxy-3,5-dibromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,
5-dimethylphenyl) propane, 3,9-bis [2-
{3- (3-tert-butyl-4-hydroxy-5-
Methylphenyl) propylniloxy {-1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] andecan, tetrakis- [methylene-3-
(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] -a phenol compound such as methane, 1,4-diglycidyloxybenzene,
4'-diglycidyloxydiphenyl sulfone, 4-benzyloxy-4 '-(2-methylglycidyloxy)
Epoxy compounds such as diphenyl sulfone, diglycidyl terephthalate, cresol novolak type epoxy resin, phenol novolak type epoxy resin and bisphenol A type epoxy resin, N, N'-di-2-naphthyl-p-
Phenylenediamine, 2,2'-methylenebis (4,6
-Di-tert-butylphenyl) phosphate, sodium or polyvalent metal salts, and bis (4-ethyleneiminocarbonylaminophenyl) methane. Of course, the present invention is not limited to these.
It is also possible to use more than one species in combination. Among these preservative improvers, in particular, in the measurement by the melting point and melting range measurement methods specified in JIS K0064, after leaving for 5 minutes after the end point of melting, the capillary containing the sample is removed within 20 seconds. A hindered phenolic compound which does not cause crystallization as defined in JIS K0211 even after being left to stand in an atmosphere of ± 1 ° C. for 48 hours is preferably used because more excellent recorded image stability can be obtained. In particular, a hindered phenol compound represented by the following general formula (2) can be preferably used because more excellent recorded image stability can be obtained.

[0027]

Embedded image

(N is an integer of 1 to 3, R_Two Is tert-
Butyl or cyclohexyl, R _Three , R_Four Each
Methyl or hydrogen, R_Five Is an alkyl having 4 or less carbon atoms
Group, isocyanuric acid derivative, or a group selected from sulfur
Represents, R_Two Is the carbon atom adjacent to the carbon atom to which the OH group is bonded
Bond to an atom. As a specific example of the general formula (2), for example, 4,4′-butyl
Redidenbis (6-tert-butyl-m-cresol)
), 1,1,3-tris (2-methyl-4-hydroxy
(Cy-5-cyclohexylphenyl) butane, 1,3,5
-Tris (4-tert-butyl-3-hydroxy-
2,6-dimethylbenzyl) isocyanuric acid, 1,1,
3-tris (2-methyl-4-hydroxy-5-ter
t-butylphenyl) butane and the like. these
Among the compounds, 1,1,3-tris (2-methyl-4-
Hydroxy-5-cyclohexylphenyl) butane
Such asymmetric molecules are particularly preferred.

As the ultraviolet absorbent of the present invention, various known substances can be used. Above all, benzotriazole-based UV absorbers are preferred in terms of UV absorption efficiency. Particularly when using UV absorbers in microcapsules, it is necessary to dissolve the UV absorber in an organic solvent for liquids at room temperature. Since it is not contained, it can be contained in a microcapsule at a high concentration, and the ultraviolet absorbing ability is remarkably improved. Specific examples of the benzotriazole-based ultraviolet absorber which is liquid at ordinary temperature include, for example, the following. 2- (2'-hydroxy-3'-dodecyl-5'-methylphenyl) benzotriazole, 2
-[2'-hydroxy-4 '-(2 "-ethylhexyl) oxyphenyl] benzotriazole, methyl-3
-[3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate-polyethylene glycol (molecular weight about 300)
And octyl 5-tert-butyl-3- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxybenzene-propionate, 2- (2'-hydroxy-3'-sec- Butyl-5'-tert-butylphenyl) -5-tert-butylbenzotriazole and the like.

The benzotriazole derivatives which are solid at room temperature include 2- (2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'- Hydroxy-5'-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t
tert-butylphenyl) benzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-
Methylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl)-
5-tert-butylbenzotriazole, 2- (2 '
-Hydroxy-3'-sec-butyl-5'-tert
-Butylphenyl) -5-tert-butylbenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-
tert-amylphenyl) -5-tert-amylbenzotriazole, 2- [2′-hydroxy-3′-
(3 ", 4", 5 ", 6" -tetrahydrophthalimido-methyl) -5'-methylphenyl] benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, N, N '-Bis [[2-hydroxy-3- (2H-benzotriazol-2-yl) -5-methylphenyl] methyl] -terephthalamide and the like. Other UV absorbers include salicylic acid UV absorbers such as phenyl salicylate, p-tert-butylphenyl salicylate and p-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, Hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4 Benzophenone-based ultraviolet absorbers such as -methoxy-5-sulfobenzophenone, 2-ethylhexyl-2-cyano-3,
3'-diphenyl acrylate, ethyl-2-cyano-
Cyanoacrylate-based ultraviolet absorbers such as 3,3'-diphenylacrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl succinate) Hindered amine ultraviolet absorbers such as -4-piperidyl) ester and 2- (3,5-di-tert-butyl) malonic acid-bis (1,2,2,6,6-pentamethyl-4-piperidyl) ester Is mentioned. Of course, it is not limited to these, and it is also possible to use two or more of them as needed. When an ultraviolet absorber is used, it is contained in at least one of the layers constituting the heat-sensitive recording medium. However, the layers of the heat-sensitive recording medium of the present invention include a support, a heat-sensitive layer, an intermediate layer, a protective layer, and a back surface of the support. And at least one of all the layers constituting the thermosensitive recording medium, such as a coating layer between the support and the thermosensitive layer.

The coating layer that can be provided on the back surface of the support and / or between the support and the heat-sensitive recording layer is, for example, the heat-sensitive recording layer sandwiched between the supports in the case of the back surface of the support. It may be provided on the surface on the side opposite to that described above. For example, one or more additional coating layers may be provided between the support and the back coating layer. (A side opposite to the support with the backside coating layer therebetween), one or more coating layers may be provided. Similarly, when the coating layer is provided between the support and the thermosensitive recording layer, the coating layer may be located between the support and the thermosensitive recording layer. Between the coating layer and the heat-sensitive recording layer, another coating layer may be provided one or more layers. It may be.

In the present invention, when an ultraviolet absorber is contained in a microcapsule, there are many advantages such as excellent transparency and stability against a plasticizer and the like.

The amount of the ultraviolet absorber incorporated into the thermosensitive recording medium layer containing the support should be appropriately selected according to the type of the ultraviolet absorber, the concentration in the capsule, and the desired quality. In general, it is desirable to adjust the amount in the range of about 5 to 80% by weight based on the total solid content of the layer to be contained.

When the ultraviolet absorber is microencapsulated, it can be prepared by various known methods, specifically, for example, JP-A-5-229255 and JP-A-6-3438.
It can be prepared by the method exemplified in 53. Furthermore, by making the microcapsules a microcapsule having a wall film made of polyurethane, polyurea resin or aminoaldehyde resin, more excellent chemical resistance,
Transparency can be obtained.

As light stabilizers, organometallic compounds such as nickel bis (octylphenyl) sulfide, [2,2'-thiobis (4-tert-octylphenolate)]-n-butylamine nickel, and hindered amine light stabilizers Stabilizers. Of course, the present invention is not limited to these, and two or more of them can be used as needed.

When using the above sensitizers, preservative improvers, ultraviolet absorbers, and light stabilizers, it is necessary to evaluate the desensitizing effect, decolorizing effect, and ground coloring effect, and select a material that meets the purpose. There is. The coating solution for the heat-sensitive recording layer may be any one as long as the colorant is uniformly dispersed using the above-described organic solvent as a dispersion medium, and a dye,
The binder resin and other additives may be simultaneously dispersed with a sand mill or the like, or only the colorant is dispersed in a solvent with a sand mill or the like, and then the dye and the binder resin are added to the colorant dispersion. Various preparation methods are possible. The colorant after dispersion may take various particle shapes, but when transparency is required, the average value of the long diameter is 5%.
Dispersion of less than μm gives good results in transparency.

In the present invention, by providing a protective layer on the heat-sensitive recording layer, it is possible to improve the stability of the recorded image and the suitability for printing. Further, one or more intermediate layers may be provided between the heat-sensitive recording layer and the protective layer. By providing two or more layers, it is possible to further improve the stability of the recorded image and the printability.
Specific examples of the resin that can be contained in the intermediate layer and the protective layer in the present invention include, for example, oxidized starch,
Starches such as enzyme-modified starch, cation-modified starch, esterified starch, and etherified starch; cellulosic resins such as methylcellulose, carboxymethylcellulose, methoxycellulose, hydroxyethylcellulose, and nitrocellulose; complete (or incomplete) saponified polyvinyl alcohol; Modified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, polyvinyl alcohol such as silicon-modified polyvinyl alcohol, acrylic resin, polyvinylpyrrolidone, styrene / maleic anhydride copolymer and its alkali salt, isobutylene / maleic anhydride copolymer and its Alkaline salt, casein, gelatin, polyvinyl acetate resin, coumarone resin, nylon resin, polyurethane resin, polyester resin, polyester resin Styrene resin, styrene / butadiene copolymer, vinyl chloride resin, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl acetate copolymer, styrene / butadiene / acrylic copolymer, polyvinyl acetal resin, ionizing Radiation curable resins and the like can be mentioned. Among them, the resin used for the intermediate layer is preferably a polyester resin, particularly preferably an aqueous polyester resin, for example, a resin containing terephthalic acid and ethylene glycol as main components. Of course, the present invention is not limited to these, and two or more of them can be used in combination as needed.

The amount of the resin used in the intermediate layer and the protective layer is desirably adjusted in the range of 10 to 90% by weight based on the total solid content of the intermediate layer and the protective layer.

The intermediate layer / protective layer contains, in addition to the above resins, a lubricant, if necessary, and the pigments, cross-linking agents, preservative improvers, ultraviolet absorbers, light stabilizers and the like exemplified for the heat-sensitive recording layer. It is possible to do. The amount of the pigment used in the intermediate layer / protective layer is not particularly limited, but is preferably adjusted in the range of 0 to 80% by weight based on the total solid content of the intermediate layer / protective layer.

Examples of the lubricant used include waxes such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax and ester wax, and alkyl phosphorus such as lauryl phosphate, oleyl phosphate and stearyl phosphate. Acid esters and alkali metal salts thereof, glyceryl monomyristate, glyceryl monostearate, glyceryl monooleate, glyceryl fatty acid esters such as glyceryl distearate, glyceryl dioleate, diglyceryl monolaurate, diglyceryl dilaurate, monolauric acid Polyglycerol fatty acid esters such as tetraglyceryl, hexaglyceryl monolaurate, decaglyceryl monolaurate, and silicone oils are available. Desensitizing effect from, color erasing action, to evaluate the background color development action, it is necessary to select a material that matches the purpose. Of course, the present invention is not limited to these, and two or more of them can be used in combination as needed.

The coating liquid for the intermediate layer and the protective layer is prepared by mixing and stirring a resin, a pigment, a lubricant and the like with an ionizing radiation curable resin or a dispersion medium of water, an organic solvent, a mixed solvent of water and an organic solvent. It is prepared by In such a coating liquid, if necessary, a crosslinking agent, a preservability improver, an ultraviolet absorber, a light stabilizer,
For example, an auxiliary agent such as a dispersant, an antifoaming agent, a coloring dye, and a fluorescent dye can be added.

The material used for the intermediate layer and the protective layer must be selected in consideration of the balance between printability, chemical resistance, storage stability, light resistance and transparency in the combination of the intermediate layer and the protective layer. However, in particular, it is desirable to select and adjust the intermediate layer by selecting a material having good adhesion to the heat-sensitive recording layer and the protective layer by selecting a material having good head matching with the heat-sensitive head.

The coating amounts of the intermediate layer and the protective layer are each 0.1 to 20 g / m ^2, preferably 0.5 to 10 g / m ^2.
It is desirable to adjust within the range of about m ² . 0.1 g / m
^The effect cannot be fully exhibited with a coating amount of ² full, and 20 g / m
^{If the} coating amount exceeds ² , it is difficult to obtain sufficient sensitivity.

The method for forming the solvent coating layer, the protective layer, the intermediate layer and the other coating layers of the heat-sensitive recording layer is not particularly limited, and examples thereof include air knife coating, variver blade coating, pure blade coating, rod blade coating, and the like. Short dwell coating, curtain coating, die coating, gravure coating, offset gravure coating, 5
It is formed by an appropriate coating method such as the roll coating.

The support has a thickness of 4 to 250 μm.
m, preferably a plastic film of 20 to 200 μm, synthetic paper or paper is appropriately selected and used. When used in transmitted light, a transparent or translucent plastic film is suitable, a cellulose derivative film such as a cellulose triacetate film, polyethylene terephthalate, polybutylene terephthalate, a polyester film such as polyethylene naphthalate, polyethylene, Polyolefin film such as polypropylene, polyvinyl chloride film, polycarbonate film,
Polyamide-based film, polysulfone film, polyethersulfone film, polyetheretherketone film, polyetherimide film, polyphenylenesulfide film, polyesterether film, polyamideimide film, fluororesin film,
Polyurethane film, acrylic film, polyvinyl butyral film, polystyrene film, polyvinyl alcohol film, and other synthetic resin films can be used alone or bonded together.

Further, various known techniques in the field of heat-sensitive recording material production can be applied by applying a pressure-sensitive adhesive treatment to the back surface to process the pressure-sensitive adhesive label, or by providing a magnetic layer. Of course, after forming the heat-sensitive recording layer, the intermediate layer, and the protective layer, a super-calender treatment can be performed to improve the image quality and the image density.

[0047]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted to such specific Examples. Parts and% in Examples are parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 Preparation of Coating Solution for Protective Layer 100 parts of a 10% aqueous solution of acetoacetylated polyvinyl alcohol (trade name: Gosefimer Z-200, manufactured by Nippon Synthetic Chemical Company), kaolin (trade name: UW-) 90, EMC
20 parts, 10 parts of sodium dioctylsulfosuccinate
% Of an aqueous solution, 6 parts of a zinc stearate dispersion having a solid content of 30%, 2 parts of a 5% aqueous glyoxal solution, and 119 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. Preparation of coating solution for heat-sensitive recording layer N- (p-toluenesulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
-Diethylamino-6-methyl-7-anilino-l-orane (60 parts), polyvinyl butyral resin (trade name: Denkabutyral # 3000-2, manufactured by Denki Kagaku), 30 parts, and methyl ethyl ketone (850 parts) dispersed by a sand mill using a sand mill to obtain an average particle size of dispersed particles (Measured with Microtrack HRA, Model 9320-X100, manufactured by Leads + Northrup)
Was adjusted to 1.0 μm to obtain a coating liquid. -Formation of heat-sensitive recording medium On a synthetic paper (Yupo FPG-80, manufactured by Oji Yuka Synthetic Paper Co., Ltd.), the coating amount of the above heat-sensitive recording layer coating solution after drying was 5 g /
After the coating dried so that m ^2, the coating amount after drying a protective layer coating solution thereon to obtain a heat-sensitive recording material by coating dried so that 3 g / m ^2.

Example 2 In the preparation of the coating solution for the heat-sensitive recording layer of Example 1, N- (p
-Toluenesulfonyl) -N '-[4- (n-octadecanoylamino) phenyl] urea is replaced by N-
A heat-sensitive recording material was obtained in the same manner as in Example 1, except that (2-naphthylsulfonyl) -N '-[4- (n-octadecanoylamino) phenyl] urea was used.

Example 3 A heat-sensitive recording material was obtained in the same manner as in Example 1, except that the following coating solution for a heat-sensitive recording layer was used. Preparation of coating solution for heat-sensitive recording layer N- (2-naphthylsulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, polyvinyl butyral resin (trade name: Denka butyral #
3000-2, manufactured by Denki Kagaku Co., Ltd.), 30 parts of methyl ethyl ketone and 850 parts of methyl ethyl ketone were dispersed in a sand mill using an average particle size (L) of dispersed particles.
micros HR made by eeds + Northrup
A, measured with model 9320-X100) 1.0 μm
Then, 60 parts of 3-diethylamino-6-methyl-7-anilinofluoran was added to obtain a coating solution for a heat-sensitive recording layer.

Example 4 Preparation of Coating Liquid for Protective Layer 100 parts of 10% aqueous solution of acetoacetylated polyvinyl alcohol (trade name: Gosefimer Z-200, manufactured by Nippon Synthetic Chemical Company), colloidal silica having a solid concentration of 20% (Trade name: Snowtex O, manufactured by Nissan Chemical Co., Ltd.) 100 parts, 3 parts of a 10% aqueous solution of dioctyl sodium sulfosuccinate, 6 parts of a zinc stearate dispersion having a solid content of 30%, 2 parts of a 5% aqueous glyoxal solution, 39 parts of water Was mixed and stirred to obtain a coating liquid for a protective layer. Formation of heat-sensitive recording medium The same heat-sensitive recording layer coating solution as in Example 1 was dried on a transparent polyester film (Cosmoshine A4100, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm to a coating amount of 10 g / m ^2.
Then, the coating liquid for the protective layer was applied thereon and dried such that the coating amount after drying was 3 g / m ² to obtain a thermosensitive recording medium.

Example 5 The same heat-sensitive recording layer coating solution as in Example 2 was dried on a 100 μm-thick transparent polyester film (Cosmoshine A4100, manufactured by Toyobo Co., Ltd.) to a coating amount of 10 g / m ^2.
Then, the same coating liquid for a protective layer as in Example 4 was applied thereon and dried so that the coating amount after drying was 3 g / m ² to obtain a thermosensitive recording medium. Was.

Example 6 A heat-sensitive recording material was obtained in the same manner as in Example 1 except that 1160 parts of methyl isobutyl ketone was used instead of 850 parts of methyl ethyl ketone in the preparation of the coating solution for the heat-sensitive recording layer of Example 1.

Example 7 A heat-sensitive recording material was obtained in the same manner as in Example 4, except that the coating solution for the heat-sensitive recording layer was prepared as follows. Preparation of coating solution for heat-sensitive recording layer N- (2-naphthylsulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
60 parts of diethylamino-6-methyl-7-anilinofluoran, 30 parts of polyvinyl butyral resin (trade name: Denkabutyral # 3000-K, manufactured by Denki Kagaku),
1,1,3-tris (2-methyl-4-hydroxy-5
-Cyclohexylphenyl) butane (9 parts) and methyl ethyl ketone (850 parts) were dispersed in a sand mill with an average particle size of 1.0 (measured by Microtrack HRA manufactured by Leads + Northrup, model 9320-X100).
The dispersion was performed so as to obtain a coating liquid. Example 8 A heat-sensitive recording material was obtained in the same manner as in Example 4, except that the coating solution for the heat-sensitive recording layer was prepared as follows. Preparation of coating solution for heat-sensitive recording layer N- (2-naphthylsulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
60 parts of diethylamino-6-methyl-7-anilinofluoran, 6 parts of polyvinyl butyral resin (trade name: Denkabutyral # 3000-K, manufactured by Denki Kagaku), 1,
9 parts of 1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane and 850 parts of methyl ethyl ketone were dispersed in a sand mill to obtain an average particle diameter of dispersed particles (Le).
eds + Northrup Microtrack HR
A, measured with model 9320-X100) 1.0 μm
The polyester resin (trade name: Byron UR1400, solid content 30%,
80 parts of a glass transition temperature of 83 ° C., manufactured by Toyobo) was added to obtain a coating liquid.

Comparative Example 1 Preparation of coating solution for heat-sensitive recording layer Preparation of solution A 100 parts of 3-diethylamino-6-methyl-7-anilinofluoran, 25 parts of a 5% aqueous solution of methylcellulose,
25 parts of a 5% aqueous solution of polyvinyl alcohol and 100 parts of water were sand-milled to obtain an average particle size of dispersed particles (Leeds + N
Orthrup Microtrack HRA, Model 9
(Measured at 320-X100) to be 1.0 μm to obtain a coating liquid. Preparation of Liquid B 50 parts of 4,4′-isopropylidene diphenol, 25 parts of a 5% aqueous solution of methylcellulose, 25 parts of a 5% aqueous solution of polyvinyl alcohol, and 100 parts of water were subjected to a sand mill with an average particle diameter of dispersed particles (Leeds + Northrup Co.) (Trade name, manufactured by Microtrac HRA, model 9320-X100) was 1.0 μm to obtain a coating liquid. 25 parts of solution A, 40 parts of solution B, and 85 parts of a 5% aqueous solution of polyvinyl alcohol were mixed and stirred to obtain a thermosensitive recording layer coating solution. Formation of heat-sensitive recording material A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the thus obtained coating solution for the heat-sensitive recording layer was used.

Comparative Example 2 In Comparative Example 1, N- (p-toluenesulfonyl) -N'- was used instead of 4,4'-isopropylidenediphenol.
A thermosensitive recording medium was obtained in the same manner as in Comparative Example 1, except that [4- (n-octadecanoylamino) phenyl] urea was used.

Comparative Example 3 In Example 1, N- (p-toluenesulfonyl) -N'-
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that 4,4'-isopropylidenediphenol was used instead of [4- (n-octadecanoylamino) phenyl] urea. Immediately after coating, the ground completely developed color.

Comparative Example 4 A heat-sensitive recording material was obtained in the same manner as in Example 4, except that the same heat-sensitive recording layer coating solution as in Comparative Example 2 was used.

<Printing of thermosensitive recording medium> Each thermosensitive recording medium was colored with an applied energy of 0.30 and 0.40 mj / dot using a thermosensitive evaluation machine (trade name: THPMD, manufactured by Okura Electric Co., Ltd.). . <Measurement of Recording Density> The color-developed thermosensitive recording medium was placed on white paper, and a Macbeth densitometer (RD-914, manufactured by Macbeth)
Was used to measure the reflection recording density. <Evaluation of storage stability> The color-developed thermosensitive recording medium was heated at 40 ° C and 90%.
Aging was performed for 24 hours using a RH constant temperature and humidity apparatus, and the change in recording density in the halftone area was measured.

[0060]

[Table 1]

Further, Examples 4, 5 and Comparative Example 4
Table 2 shows the results of measurement of the haze value of the heat-sensitive recording material obtained by using a haze meter (trade name: TC-H1V, manufactured by Tokyo Denshoku).

[0062]

[Table 2]

Example 9 Preparation of Coating Solution for Protective Layer 20 parts of kaolin (trade name: UW-90, manufactured by EMC),
Carboxy-modified polyvinyl alcohol (trade name: Gohsenal T-215, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10% aqueous solution 5
00 parts, 9 parts of a zinc stearate dispersion having a solid content of 40%,
A composition comprising 95 parts of a 10% aqueous glyoxal solution, 110 parts of a 12.5% aqueous solution of polyamide epichlorohydrin, 95 parts of a 5% aqueous solution of sodium dioctylsulfosuccinate, and 500 parts of water is mixed and stirred to form a coating for the protective layer. A liquid was obtained.・ Preparation of solution A Heating device and Coreless stirrer (Model: J-25X, Mo
A tank having an inner diameter of 800 mm at the bottom provided with a high shear impeller (manufactured by Reuse Industries, Inc., 240 mm in diameter) has a polymerization degree of 1000 and a saponification degree of 96 mo.
acetoacetyl group-modified polyvinyl alcohol using 1% polyvinyl alcohol as a raw material (denaturation degree 4.5 m)
ol%) of a 12.5% aqueous solution was added to obtain an aqueous medium for producing capsules. Separately, 42 kg of 2- (2'-hydroxy-3'-dodecyl-5'-methylphenyl) benzotriazole and a hexamethylene diisocyanate derivative (trade name: Takenate D) whose main component is a trimer of isocyanurate-type hexamethylene diisocyanate −
A solution obtained by heating and mixing and stirring 18 kg of 170 HN (manufactured by Takeda Pharmaceutical Co., Ltd.) to 40 ° C. was dispersed in the above aqueous medium for capsule production while cooling at 2400 rpm for 20 minutes using a Cores stirrer. The average particle size of the dispersion was 1.5 μm. Next, water 10 was added to the dispersion.
After adding 0 kg, the mixture was reacted at 90 ° C. for 5 hours with stirring to prepare a microcapsule dispersion having a wall film made of a polyurea / polyurethane resin. The average particle diameter of the dispersion after the reaction was 1.5 μm. Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition consisting of 250 parts of Nissan Chemical Co., Ltd. and 100 parts of Liquid A was mixed and stirred to obtain a coating liquid for an intermediate layer. Preparation of coating solution for heat-sensitive recording layer N- (2-naphthylsulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
-Diethylamino-6-methyl-7-anilinofluorane (40 parts), polyvinyl butyral resin (trade name: Denkabutyral # 3000-K, manufactured by Denki Kagaku Co., Ltd.), and methyl ethyl ketone (850 parts) were dispersed in a sand mill to give an average particle size of dispersed particles. Diameter (measured with Leeds + Northrup Microtrac HRA, model 9320-X100)
Was adjusted to 1.0 μm to obtain a coating liquid. Preparation of Liquid B Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition consisting of 125 parts of Nissan Chemical Co., Ltd.) and 100 parts of Liquid A was mixed and stirred to obtain Liquid B. And heat-sensitive transparent polyester film of the recording member forming thickness 100μm of (Cosmo Shine A4100, manufactured by Toyobo Co., Ltd.) on, so that the coating amount after drying the heat-sensitive recording layer coating liquid is 15 g / m ² After coating and drying, a coating liquid for an intermediate layer and a coating liquid for a protective layer are successively coated and dried so that the coating amount after drying is 3 g / m ² . Further, the liquid B was coated and dried on the back surface of the support so that the coated amount after drying was 3 g / m 2, to obtain a thermosensitive recording medium.

Example 10 In the preparation of the coating solution for the heat-sensitive recording layer of Example 9, N-
Instead of (2-naphthylsulfonyl) -N '-[4- (n-octadecanoylamino) phenyl] urea, N
A heat-sensitive recording material was obtained in the same manner as in Example 9, except that-(p-toluenesulfonyl) -N '-[4- (n-octadecanoylamino) phenyl] urea was used.

Example 11 Preparation of Coating Solution for Thermosensitive Recording Layer N- (2-naphthylsulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, polyvinyl butyral resin (trade name: Denka butyral #
30 parts of 3000-K, manufactured by Denki Kagaku Co., Ltd.) and 850 parts of methyl ethyl ketone were dispersed in a sand mill using an average particle size (L
micros HR made by eeds + Northrup
A, measured with model 9320-X100) 1.0 μm
Then, 60 parts of 3-diethylamino-6-methyl-7-anilinofluoran was added to obtain a coating solution for a heat-sensitive recording layer. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the above-mentioned coating solution for a heat-sensitive recording layer was used.

Example 12 Preparation of Coating Solution for Protective Layer 20 parts of kaolin (trade name: UW-90, manufactured by EMC),
Carboxy-modified polyvinyl alcohol (trade name: Gohsenal T-215, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10% aqueous solution 5
00 parts, A part 100 parts, 10% glyoxal aqueous solution 9
A composition consisting of 5 parts, 110 parts of a 12.5% aqueous solution of polyamide epichlorohydrin, 95 parts of a 5% aqueous solution of sodium dioctylsulfosuccinate, and 500 parts of water was mixed and stirred to obtain a coating liquid for a protective layer. . Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition consisting of 250 parts (manufactured by Nissan Chemical Industries, Ltd.) was mixed and stirred to obtain a coating liquid for an intermediate layer. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the coating liquid for the intermediate layer and the coating liquid for the protective layer were used.

Example 13 Preparation of Coating Solution for Protective Layer 20 parts of kaolin (trade name: UW-90, manufactured by EMC),
Carboxy-modified polyvinyl alcohol (trade name: Gohsenal T-215, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10% aqueous solution 5
00 parts, 65 parts of solution A, zinc stearate dispersion having a solid content of 40%, 95 parts of a 10% aqueous glyoxal solution, 110 parts of a 12.5% aqueous solution of polyamide epichlorohydrin, 95 parts of a 5% aqueous solution of sodium dioctyl sulfosuccinate And a composition comprising 500 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition comprising 250 parts of Nissan Chemical Co., Ltd. and 50 parts of Liquid A was mixed and stirred to obtain a coating liquid for an intermediate layer. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the coating liquid for the intermediate layer and the coating liquid for the protective layer were used.

Example 14 Preparation of Solution C 312 parts of an 8% aqueous solution of polyvinyl alcohol (trade name: PVA-217, manufactured by Kuraray Co., Ltd.), kaolin (trade name: U
A composition consisting of 25 parts of W90 (manufactured by EMC) and 100 parts of solution A was mixed and stirred to obtain solution C. 100 μm thick transparent polyester film (Cosmo Shine A410
0, manufactured by Toyobo Co., Ltd.) and dried so that the coating amount after drying the liquid C would be 3 g / m ^2, and then the same thermal recording as in Example 9 was performed on the coating layer of the liquid C. The layer coating solution was coated and dried so that the coating amount after drying was 15 g / m ^2, and then a coating solution for an intermediate layer as in Example 9 and a coating solution for a protective layer as in Example 9 The coating solutions were sequentially dried so that the coating amounts after drying were both 3 g / m ² .

Example 15 A thermosensitive recording medium was obtained in the same manner as in Example 9 except that the solution B was not applied.

Example 16 Preparation of Coating Solution for Thermosensitive Recording Layer N- (2-naphthylsulfonyl) -N ′-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
-Diethylamino-6-methyl-7-anilinofluoran 23.6 parts, 3- {1,1-bis (1-ethyl-2-
Methylindol-3-yl)}-3-p-diethylaminophenylphthalide 4 parts, 3-diethylamino-6
18.4 parts of 8-dimethylfluorane, 12 parts of 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, polyvinyl butyral resin (trade name: Denkabutyral # 3000-K, electricity) Chemical parts) (40 parts) and 850 parts of methyl ethyl ketone were dispersed in a sand mill using an average particle size of dispersed particles (Leeds + Northr).
microtrac HRA, model 9320-X
(Measured at 100) was 1.0 μm to obtain a coating liquid. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the above-mentioned compound was used as the coating solution for the heat-sensitive recording layer in Example 9. Example 17 Preparation of Coating Solution for Thermosensitive Recording Layer N- (2-naphthylsulfonyl) -N ′-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
-Diethylamino-6-methyl-7-anilinofluoran 40 parts, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane 6 parts, 2
6 parts of-(2-hydroxy-3,5-di-t-butylphenyl) benzotriazole, 40 parts of polyvinyl butyral resin (trade name: Denkabutyral # 3000-K, manufactured by Denki Kagaku), and 850 parts of methyl ethyl ketone in a sand mill. Average particle size of dispersed particles (Leeds + North
Rup Microtrac HRA, Model 9320-
(Measured at X100) is 1.0 μm,
A coating liquid was obtained. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the above-mentioned compound was used as the coating solution for the heat-sensitive recording layer in Example 9.

Example 18 Preparation of Coating Solution for Intermediate Layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition consisting of 250 parts (manufactured by Nissan Chemical Industries, Ltd.) was mixed and stirred to obtain a coating liquid for an intermediate layer. A thermosensitive recording medium was obtained in the same manner as in Example 9 except that the above-mentioned coating solution for an intermediate layer was used.

Example 19 Preparation of Solution D A composition comprising 10 parts of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 5 parts of a 5% aqueous solution of methylcellulose, and 40 parts of water was averaged with a sand mill. It was pulverized until the particle diameter became 1.5 μm. Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition comprising 250 parts of Nissan Chemical Co., Ltd. and 83 parts of Liquid D was mixed and stirred to obtain a coating liquid for an intermediate layer. A thermosensitive recording medium was obtained in the same manner as in Example 9 except that the above-mentioned coating solution for an intermediate layer was used.

Comparative Example 5 Preparation of coating solution for heat-sensitive recording layer Preparation of solution E 100 parts of 3-diethylamino-6-methyl-7-anilinofluoran, 25 parts of a 5% aqueous solution of methylcellulose,
25 parts of a 5% aqueous solution of polyvinyl alcohol and 100 parts of water were sand-milled to obtain an average particle size of dispersed particles (Leeds + N
Orthrup Microtrack HRA, Model 9
(Measured at 320-X100) to be 1.0 μm to obtain a coating liquid. Preparation of Solution F 50 parts of 4,4′-isopropylidenediphenol, 25 parts of a 5% aqueous solution of methylcellulose, 25 parts of a 5% aqueous solution of polyvinyl alcohol, and 100 parts of water were subjected to a sand mill with an average particle diameter of dispersed particles (Leeds + Northrup Co.) (Trade name, manufactured by Microtrac HRA, model 9320-X100) was 1.0 μm to obtain a coating liquid. 25 parts of the E liquid, 40 parts of the F liquid, and 85 parts of a 5% aqueous solution of polyvinyl alcohol were mixed and stirred to obtain a thermosensitive recording layer coating liquid. Formation of heat-sensitive recording material A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the thus obtained coating solution for a heat-sensitive recording layer was used.

Comparative Example 6 In Comparative Example 5, N- (p-toluenesulfonyl) -N'- was used instead of 4,4'-isopropylidenediphenol.
A heat-sensitive recording material was obtained in the same manner as in Comparative Example 5, except that [4- (n-octadecanoxy) phenyl] urea was used.

<Evaluation of Transparency> The haze value of the thermal recording medium was measured using a haze meter (trade name: TC-H1V, manufactured by Tokyo Denshoku).
<Evaluation of light fastness> After exposing the front or back surface of the thermosensitive recording medium to direct sunlight for 2 days, a Macbeth densitometer (TR-927) was used.
(Macbeth Co., Ltd.) to measure the transmission density of the background. <Evaluation of Chemical Resistance> The thermosensitive recording medium was immersed in 70% ethanol for 2 minutes, and the surface state was visually evaluated. ：: No change ○: Almost no change ×: There is change <Printing of thermal recording medium> Thermal evaluation machine (trade name: THPM)
D, manufactured by Okura Electric Co., Ltd.). <Measurement of Recording Density> The transmission density of the heat-sensitive recording medium after color development was measured by a Macbeth densitometer (TR-927, manufactured by Macbeth). <Evaluation of storage stability> The colored thermosensitive recording medium was dried at 60 ° C.
Aging was performed for 24 hours using a constant-temperature and humidity apparatus, and the change in recording density was measured.

[0076]

[Table 3]

[0077]

[Table 4]

Further, Table 5 shows the transmission density of the background portion when the back surface of the thermal recording medium obtained in Example 9 and Examples 14 to 17 was exposed to direct sunlight for 2 days.

[0079]

[Table 5]

[0080]

As is clear from the results in Table 1, the color former is a compound represented by the general formula (1), and the heat-sensitive recording layer is formed by applying an organic solvent-based coating solution. Thus, a thermosensitive recording medium having extremely high print storage stability even in the halftone region was obtained. Further, a highly transparent film is used for the base material, the colorant is a compound represented by the general formula (1), and the heat-sensitive recording layer is formed by applying an organic solvent-based coating liquid,
By providing the protective layer having high transparency, a heat-sensitive recording medium having high transparency was obtained. Further, from the results in Tables 3 and 4, it was found that by including an ultraviolet absorber in the layer constituting the heat-sensitive recording medium, the stability of the recorded image was good, and the heat-sensitivity was excellent in chemical resistance, light resistance and transparency. A recording was obtained.

[Procedure amendment]

[Submission date] June 24, 1999 (1999.6.2
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009] thermosensitive recording medium of the present invention is the sensitive thermal recording body provided with a heat-sensitive recording layer containing a color developer and a basic dye on a support is represented by the following general formula (1) as color acceptor Wherein the heat-sensitive recording layer is formed by coating using an organic solvent-based coating liquid.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

[0015]

Embedded image

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

The strength of the heat-sensitive layer can be improved by including an adhesive in the heat-sensitive layer. The adhesive used in the heat-sensitive layer is not particularly limited as long as it is a resin soluble in an organic solvent, but a thermoplastic resin is particularly preferably used, and a thermoplastic resin soluble in the organic solvent as described above. still more are preferably used, and specific examples thereof include acrylic resins, polystyrene resins, poly α- methyl styrene resin, vinyl chloride resin, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyvinyl Acetal- based resins and the like, and cellulose-based polymers such as nitrocellulose, polyester-based resins, polyurethane-based resins, cumarone-based resins, nylon-based resins, and the like, but of course, are not limited to these, two or more Resin can be used in combination. Of these resins,
If the glass transition temperature was used for more than 20 ° C. may be preferably used because the stability of the recorded image is improved, further use at least one said resin is selected from polyvinyl acetal resin and a polyester resin In this case, more excellent stability of the recorded image can be obtained, and further excellent mechanical strength of the heat-sensitive recording layer can be obtained, so that it can be more preferably used.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction contents]

Example 1 Preparation of Coating Solution for Protective Layer 100 parts of a 10% aqueous solution of acetoacetylated polyvinyl alcohol (trade name: Gosefimer Z-200, manufactured by Nippon Synthetic Chemical Company), kaolin (trade name: UW-) 90, EMC
20 parts, 10 parts of sodium dioctylsulfosuccinate
% Of an aqueous solution, 6 parts of a zinc stearate dispersion having a solid content of 30%, 2 parts of a 5% aqueous glyoxal solution, and 119 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. Preparation of coating solution for heat-sensitive recording layer N- (p-toluenesulfonyl) -N '-[4- (n-
Octadecanoylamino) phenyl] urea 60 parts, 3
- diethylamino-6-methyl-7-anilino-off Ruoran 60 parts Polyvinyl butyral resin: average particle diameter of the dispersed particles (trade name Denka Butyral # 3000-2, Denki Kagaku) 30 parts of methyl ethyl ketone 850 parts sand mill (Measured with Microtrack HRA, Model 9320-X100, manufactured by Leads + Northrup)
Was adjusted to 1.0 μm to obtain a coating liquid. -Formation of heat-sensitive recording medium On a synthetic paper (Yupo FPG-80, manufactured by Oji Yuka Synthetic Paper Co., Ltd.), the coating amount of the above heat-sensitive recording layer coating solution after drying was 5 g /
After the coating dried so that m ^2, the coating amount after drying a protective layer coating solution thereon to obtain a heat-sensitive recording material by coating dried so that 3 g / m ^2.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0055

[Correction method] Change

[Correction contents]

Comparative Example 1 Preparation of Coating Solution for Thermal Recording Layer Preparation of One Solution 100 parts of 3-diethylamino-6-methyl-7-anilinofluoran, 25 parts of a 5% aqueous solution of methylcellulose,
Polyvinyl alcohol (trade name: PVA-110, Kura
5% aqueous solution 25 parts manufactured by Les Ltd.), the average particle diameter of the dispersed particles 100 parts of water in a sand mill (Leeds + Northru
Microtrack HRA, model 9320-X1, manufactured by p.
(Measured at 00) to be 1.0 μm to obtain a coating liquid. Preparation of two liquids 50 parts of 4,4′-isopropylidene diphenol, 25 parts of a 5% aqueous solution of methylcellulose, 25 parts of a 5% aqueous solution of polyvinyl alcohol (trade name: PVA-110, manufactured by Kuraray Co., Ltd.) and 100 parts of water The dispersion particles were dispersed in a sand mill such that the average particle diameter of the dispersed particles (measured by Microtrac HRA manufactured by Leads + Northrup, model 9320-X100) was 1.0 μm to obtain a coating liquid. 1 liquid 2
5 parts, 2 parts 40 parts, polyvinyl alcohol (trade name: P
VA-110 (manufactured by Kuraray Co., Ltd.) (85 parts ) of a 5% aqueous solution was mixed and stirred to obtain a thermosensitive recording layer coating solution. Formation of heat-sensitive recording material A heat-sensitive recording material was obtained in the same manner as in Example 1 except that the thus obtained coating solution for the heat-sensitive recording layer was used.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0066

[Correction method] Change

[Correction contents]

Example 12 Preparation of Coating Solution for Protective Layer 20 parts of kaolin (trade name: UW-90, manufactured by EMC),
Carboxy-modified polyvinyl alcohol (trade name: Gohsenal T-215, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10% aqueous solution 5
00 parts, 9 parts of 40% zinc stearate dispersion liquid, liquid A 1
A mixture consisting of 00 parts, 95 parts of a 10% aqueous glyoxal solution, 110 parts of a 12.5% aqueous solution of polyamide epichlorohydrin, 95 parts of a 5% aqueous solution of sodium dioctylsulfosuccinate, and 500 parts of water are mixed and stirred to form a protective layer. An application liquid was obtained. Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition consisting of 250 parts (manufactured by Nissan Chemical Industries, Ltd.) was mixed and stirred to obtain a coating liquid for an intermediate layer. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the coating liquid for the intermediate layer and the coating liquid for the protective layer were used.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0067

[Correction method] Change

[Correction contents]

Example 13 Preparation of Coating Solution for Protective Layer 20 parts of kaolin (trade name: UW-90, manufactured by EMC),
Carboxy-modified polyvinyl alcohol (trade name: Gohsenal T-215, manufactured by Nippon Synthetic Chemical Co., Ltd.) 10% aqueous solution 5
00 parts, 65 parts of liquid A, 9 parts of zinc stearate dispersion having a solid content of 40%, 95 parts of 10% aqueous glyoxal solution, and 12.5% aqueous solution of polyamide epichlorohydrin 110
Part, 5% aqueous solution of sodium dioctyl sulfosuccinate 95
Parts and 500 parts of water were mixed and stirred to obtain a coating liquid for a protective layer. Preparation of coating liquid for intermediate layer Water-soluble polyester (trade name: Gabsen ES-9150)
A, manufactured by Teikoku Chemical Co., Ltd.) 100 parts of 25% aqueous solution, solid concentration 2
0% colloidal silica (trade name: Snowtex C,
A composition comprising 250 parts of Nissan Chemical Co., Ltd. and 50 parts of Liquid A was mixed and stirred to obtain a coating liquid for an intermediate layer. A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the coating liquid for the intermediate layer and the coating liquid for the protective layer were used.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0073

[Correction method] Change

[Correction contents]

Comparative Example 5 Preparation of coating solution for heat-sensitive recording layer Preparation of solution E 100 parts of 3-diethylamino-6-methyl-7-anilinofluoran, 25 parts of a 5% aqueous solution of methylcellulose,
Polyvinyl alcohol (trade name: PVA-110, Kura
5% aqueous solution 25 parts manufactured by Les Ltd.), the average particle diameter of the dispersed particles 100 parts of water in a sand mill (Leeds + Northru
Microtrack HRA, model 9320-X1, manufactured by p.
(Measured at 00) to be 1.0 μm to obtain a coating liquid. Preparation of Solution F 50 parts of 4,4′-isopropylidene diphenol, 25 parts of a 5% aqueous solution of methylcellulose, 25 parts of a 5% aqueous solution of polyvinyl alcohol (trade name: PVA-110, manufactured by Kuraray Co., Ltd.) , and 100 parts of water The dispersion particles were dispersed in a sand mill such that the average particle diameter of the dispersed particles (measured by Microtrac HRA manufactured by Leads + Northrup, model 9320-X100) was 1.0 μm to obtain a coating liquid. E liquid 2
5 parts, F liquid 40 parts, polyvinyl alcohol (trade name: P
VA-110 (manufactured by Kuraray Co., Ltd.) (85 parts ) of a 5% aqueous solution was mixed and stirred to obtain a thermosensitive recording layer coating solution. Formation of heat-sensitive recording material A heat-sensitive recording material was obtained in the same manner as in Example 9 except that the thus obtained coating solution for a heat-sensitive recording layer was used.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name]

[Correction method] Change

[Correction contents]

Comparative Example 6 In Comparative Example 5, N- (p-toluenesulfonyl) -N'- was used instead of 4,4'-isopropylidenediphenol.
[4-(n-Okutadekano yl) phenyl] except for using the urea to obtain a heat-sensitive recording material in the same manner as in Comparative Example 5.

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0075

[Correction method] Change

[Correction contents]

<Evaluation of Transparency> Haze value of heat-sensitive recording medium
The haze meter (trade name: TC-H1V, Tokyo Denshoku
<Evaluation of light fastness>
After two days exposure to light, a Macbeth densitometer (TR-927)
(Macbeth Co., Ltd.) to measure the transmission density of the background.
The light resistance in Table 3 indicates that the coated side (surface) is exposed to direct sunlight.
The light resistance of the back surface in Table 5 was such that the back surface was exposed to direct sunlight. <Evaluation of chemical resistance> The thermosensitive recording medium was immersed in 70% ethanol for 2 minutes and visually observed.
Was used to evaluate the surface condition. ：: No change ：: Almost no change ×: There is change <Printing of thermal recording medium>
D, manufactured by Okura Electric Co., Ltd.)
Was. <Measurement of recording density>
Measured with a Qubes densitometer (TR-927, manufactured by Macbeth)
Specified. <Evaluation of storage stability> The colored thermosensitive recording medium was dried at 60 ° C.
Aging for 24 hours in a constant temperature and humidity apparatus
The change in degree was measured.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Norio Yamane 1-10-6 Shinonome, Koto-ku, Tokyo Inside Oji Paper Co., Ltd. Shinonome Research Center

Claims (9)

[Claims] 1. A heat-sensitive recording medium having a heat-sensitive recording layer containing a colorant and a basic dye on a support, wherein the heat-sensitive recording layer contains a colorant represented by the following general formula (1). A heat-sensitive recording material formed by applying an organic solvent-based coating liquid. Embedded image (R ₁ represents one group selected from a phenyl group or a naphthyl group substituted or unsubstituted by an alkyl group, a halogen group, a lower alkoxy group, and Y represents the following chemical formula: Represents one group selected from divalent groups represented by
n represents an integer of 11 to 30. ) 2. The thermal recording medium according to claim 1, wherein in the general formula (1), R ₁ is unsubstituted or a naphthyl group substituted by an alkyl group, a halogen group or a lower alkoxy group. 3. An organic solvent-based coating liquid comprising methyl ethyl ketone,
The heat-sensitive recording material according to claim 1, comprising at least one of ethyl acetate and 1,3-dioxolan. 4. In the heat-sensitive recording layer, the capillary containing the sample is placed within 20 seconds within 10 seconds after standing for 5 minutes after the melting end point in the melting point and melting range measurement method specified in JIS K0064. The heat-sensitive recording material according to any one of claims 1 to 3, further comprising a hindered phenol-based compound that does not cause crystallization as specified in JIS K0211 even after being left for 48 hours in an atmosphere of ° C. 5. The heat-sensitive recording material according to claim 1, wherein a binder having a glass transition temperature of 20 ° C. or more is contained in the heat-sensitive recording layer. 6. A thermosensitive recording medium according to claim 1, further comprising a protective layer provided on the thermosensitive recording layer. 7. The heat-sensitive recording medium according to claim 6, wherein an intermediate layer is provided between the heat-sensitive recording layer and the protective layer, and the intermediate layer contains a polyester resin. 8. The thermosensitive recording medium according to claim 1, wherein at least one of the layers constituting the thermosensitive recording medium contains an ultraviolet absorber. 9. The heat-sensitive recording material according to claim 8, wherein the ultraviolet absorbent is contained in the microcapsule.