JPH07179045A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a thermal recording material excellent in the lightfastness of an image part and a background part, extremely easy to produce and excellent in workability. CONSTITUTION:In a thermal recording material wherein a thermal recording layer based on a leuco dye and a coupler making the leuco dye develop a color at the time of contact is provided on a support and a protective layer is provided on the thermal recording layer and an intermediate layer is provided between the protective layer and the thermal recording layer, an inorg. filler having an ultraviolet absorber adsorbed on the surface thereof is added to at least one of the intermediate layer, the thermal recording layer and the protective layer.

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, and more particularly to a heat-sensitive recording material which is excellent in a color image and a light resistance of a background by heat.

[0002]

2. Description of the Related Art A heat-sensitive recording material comprises a support and a heat-sensitive coloring layer containing an electron-donating colorless or light-colored dye precursor and an electron-accepting developer as main components. By heating with a head, a hot pen, a laser beam or the like, the dye precursor and the developer react instantaneously to obtain a recorded image. Such a heat-sensitive recording material has advantages that a recorded image can be obtained with a relatively simple device, maintenance is easy, and noise is reduced.
In addition to the printer field, it is widely used as a recording material for ticket vending machines. However, when using such an electron-donating dye precursor (leuco dye) and an electron-accepting color developer, there is a problem that light resistance is poor as a major drawback.
Specifically, it is easy for the colored image to fade due to irradiation with light such as sunlight, or the background (uncolored) part to turn yellow, etc. ) Was restricted.

In order to improve such a defect of the heat-sensitive recording material, for example, in JP-A-55-55891, an ultraviolet absorber such as a benzophenone derivative or a benzotriazole derivative is contained in the heat-sensitive color forming layer. 60-
No. 112487 proposes to provide an overlayer containing an ultraviolet absorber on the thermosensitive coloring layer.

However, these ultraviolet absorbers are
When used in a dispersion system, the ultraviolet absorption efficiency is poor, and a large amount of ultraviolet absorber is required to obtain the desired effect, which is not practical.

Further, in order to make the interaction between a coloring agent such as a leuco dye and an ultraviolet absorber close, it is disclosed in JP-A-50-14.
No. 6412 proposes to recrystallize a leuco dye and an ultraviolet absorber from a common solvent in order to improve light resistance, but in this case, a low melting point of the material is used due to a eutectic effect. It is not practical because it will cause the fog and the background fog to increase.

Further, in Japanese Patent Publication No. 61-57198, a sodium sulfonate group is introduced into an ultraviolet absorber, and a water-soluble compound (having a solubility in water at 25 ° C. of 1.0 or more) is treated with a triarylmethane compound or fluorane compound. It has been proposed to form a heat-sensitive recording layer by combining a system-based leuco dye and a bisphenol compound, but it has a water-soluble property by having a sodium sulfonate (SO ₃ Na) group as a substituent. It has a bad influence on the pH and liquidity of the system and also tends to cause the background part to develop color, which is not practical.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat sensitive recording material which is excellent in color image and light resistance of background.

[0008]

According to the present invention, a heat-sensitive recording layer containing a leuco dye and a developer which develops a color upon contact of the leuco dye as a main component is provided on a support, and further on the heat-sensitive recording layer. The protective layer is a thermosensitive recording material in which an intermediate layer is provided between the protective layer and the thermosensitive recording layer. In the thermosensitive recording material, an inorganic filler having an ultraviolet absorber adsorbed on its surface is formed in at least one of the intermediate layer, the thermosensitive recording layer and the protective layer. A heat-sensitive recording material characterized by being contained. Further, according to the present invention, there is provided the above thermosensitive recording material in which the specific surface area of the inorganic filler is 200 m ² / g or more, and the absorption end of the ultraviolet absorber contained as a substituent is on the longer wavelength side than 400 nm. The heat-sensitive recording material is provided.

In the present invention, examples of the inorganic filler for adsorbing the ultraviolet absorber include the followings, but the present invention is not limited thereto. Calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, surface-treated calcium and silica, etc. Further, the specific surface area of these inorganic fillers is preferably 200 m ² / g or more in view of the manifestation of the effect.

In the present invention, since the inorganic filler having the surface thereof adsorbed the ultraviolet absorber is contained in at least one of the intermediate layer, the thermosensitive recording layer and the protective layer, the ultraviolet absorptivity is maintained for a long time. It is possible to improve the light resistance. As a UV absorber, a benzophenone-based UV absorber, a benzotriazole-based UV absorber,
There are cyanoacrylate-based UV absorbers, salicylic acid-based UV absorbers, and the like, including the following.

[Benzophenone type ultraviolet absorber] 4-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4 -N-octoxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4- Methoxy-
2'-carboxybenzophenone, 2-hydroxy-4
-Oxybenzylbenzophenone, 2-hydroxy-4
-Chlorobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2-hydroxy-4-methoxy-4-
Methylbenzophenone, 2-hydroxy-4-n-heptoxybenzophenone, 2-hydroxy-3,6-dichloro-4-methoxybenzophenone, 2-hydroxy-
3,6-dichloro-4-ethoxybenzophenone, 2-
Hydroxy-4- (2-hydroxy-3-methylacryloxy) propoxybenzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane and the like.

[Benzotriazole type ultraviolet absorber] 2
-(2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-
Di-t-butylphenyl) benzotriazole, 2-
(2'-Hydroxy-3'-t-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octoxy) benzotriazole, 2-
(2'-Hydroxy-3 ', 5'-di-t-butylphenyl) 5-chlorobenzotriazole, 2- (3'-t
-Butyl-2'-hydroxy-5'-methylphenyl)
5-chlorobenzotriazole, 2- (2'-hydroxy-5-methoxyphenyl) benzotriazole, 2-
(2'-Hydroxy-5-ethoxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t -Butyl-amylphenyl)
Benzotriazole, 2- [2'-hydroxy-3'-
(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl] benzotriazole and the like. [Cyanoacrylate ultraviolet absorber] 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano-3,3'-diphenyl acrylate and the like. [Salicylic acid ultraviolet absorber] Phenyl salicylate,
p-tert-butylphenyl salicylate, p-octylphenyl salicylate and the like.

The intermediate layer in the present invention contains a filler, a binder, a heat-fusible substance and the like as basic components. In this case, specific examples of the filler, the binder, and the heat-fusible substance include the same as those exemplified in connection with the heat-sensitive recording layer described later.

Further, in the heat-sensitive recording material of the present invention, a protective layer is provided on the heat-sensitive recording layer for the purpose of improving the matching property of a thermal head or the like and further improving the storability of recorded images. Examples of the resin constituting the protective layer include polyvinyl alcohol, cellulose derivatives, starch and its derivatives, carboxyl group-modified polyvinyl alcohol, polyacrylic acid and its derivatives, styrene / acrylic acid copolymer and its derivatives, poly (meth). Water-soluble acrylamide and derivatives thereof, styrene / acrylic acid / acrylamide copolymers, amino group-modified polyvinyl alcohol, epoxy-modified polyvinyl alcohol, polyethyleneimine, aqueous polyester, aqueous polyurethane, isobutylene / maleic anhydride copolymer and its derivatives, etc. Resins, polyesters, polyurethanes, acrylate (co) polymers, styrene / acrylic copolymers, epoxy resins, polyvinyl acetate, polyvinylidene chloride, polyvinyl chloride and their derivatives. Body including but among them water-soluble resin is preferable.

In addition to the above-mentioned resins, the protective layer also contains auxiliary additives that have been conventionally used, such as fillers, surfactants, heat-fusible substances (or lubricants), and pressure-color-developing inhibitors. can do. In this case, specific examples of the filler and the heat-fusible substance include the same as those exemplified in connection with the heat-sensitive recording layer described later.

In the present invention, the leuco dyes used in the heat-sensitive recording layer may be used alone or in combination of two or more.
As such leuco dyes, those applied to this type of heat-sensitive material are arbitrarily applied, for example, triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, indolinophtalide-based, etc. Leuco compounds of dyes are preferably used. Specific examples of such leuco dyes include those shown below.

3,3-bis (p-dimethylaminophenyl)-
Phthalide, 3,3-bis (p-dimethylaminophenyl) -6
-Dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis (p-dimethylaminophenyl)
-6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-
Dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,
7-Dimethylfluorane, 3-N-methyl-N-isobutyl-6-
Methyl-7-anilinofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3- (Np-tolyl-N-ethylamino) -6-
Methyl-7-anilinofluorane, 3-pyrrolidino-6-
Methyl-7-anilinofluorane, 2- {N- (3'-trifluoromethylphenyl) amino} -6-diethylaminofluorane, 2- {3,6-bis (diethylamino) -9- (o-
Chloranilino) xanthylbenzoic acid lactam}, 3-diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutylamino-7- (o -Chloranilino) fluorane, 3-N-methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N
-Cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- (2 ', 4'-dimethylanilino ) Fluoran, 3- (N, N-diethylamino) -5
-Methyl-7- (N, N-dibenzylamino) fluorane, benzoyl leuco methylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-
3'-methoxy-benzoindolino-spiropyran, 3-
(2'-hydroxy-4'-dimethylaminophenyl) -3-
(2'-methoxy-5'-chlorophenyl) phthalide, 3- (2 '
-Hydroxy-4'-dimethylaminophenyl) -3- (2 '
-Methoxy-5'-nitrophenyl) phthalide, 3- (2'-
Hydroxy-4'-diethylaminophenyl) -3- (2'-
Methoxy-5'-methylphenyl) phthalide, 3- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-chloro-5'-methylphenyl) phthalide, 3
-Morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethyl) Anilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl)
Methylaminofluorane, 3-diethylamino-5-chloro-
7- (α-phenylethylamino) fluorane, 3- (N-ethyl
-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluorane, 3-diethylamino-5-methyl-7-
(α-Phenylethylamino) fluorane, 3-diethylamino-7-piperidinofluorane, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino) fluorane, 3-
(N-methyl-N-isopropylamino) -6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3,6-bis (dimethylamino) fluorene spiro ( 9,3 ')-6'-Dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo-7-α
-Naphthylamino-4'-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N
-(2-Ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluorane, 3-diethylamino
-6-methyl-7-mesitidino-4 ', 5'-benzofluorane, 3-
(p-Dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p-dimethylaminophenyl) -3- {1,1-bis ( p-dimethylaminophenyl) ethylene-2-yl} -6-dimethylaminophthalide,
3- (p-dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-phenylethylene-2-yl) phthalide, 3- (p-
Dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-p-chlorophenylethylene-2-yl) -6-dimethylaminophthalide, 3- (4'-dimethylamino-2'-methoxy)-
3- (1 ''-p-dimethylaminophenyl-1 ''-p-chlorophenyl-1 '', 3 ''-butadiene-4 ''-yl) benzophthalide, 3-
(4'-Dimethylamino-2'-benzyloxy) -3- (1 ''-p-dimethylaminophenyl-1 ''-phenyl-1 '', 3 ''-butadiene-4 ''-yl) benzophthalide , 3-dimethylamino-6-dimethylamino-fluorene-9-spiro 3 '(6'-dimethylamino) phthalide, 3,3-bis {2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl ) Ethenyl} -4,5,6,7-tetrachlorophthalide, 3-bis {1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl} -5,6-dichloro-4,7- Dibromophthalide, bis (p-dimethylaminostyryl) -1-naphthalenesulfonylmethane, bis (p-dimethylaminostyryl) -1
-p-tolylsulfonylmethane and the like.

As the color developer used in the heat-sensitive recording layer of the present invention, various electron-accepting compounds which develop the above leuco dye upon contact, such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic compounds Acids and metal salts thereof are preferably applied, and specific examples thereof include those shown below.

4,4'-isopropylidene bisphenol,
4,4'-isopropylidene bis (o-methylphenol),
4,4'-secondary butylidene bisphenol 4,4'-isopropylidene bis (2-tert-butylphenol), 4,4'-cyclohexylidene diphenol,
4,4'-isopropylidene bis (2-chlorophenol),
2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis
(6-tert-butyl-2-methylphenol), 1,1,3
-Tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4'-thiobis ( 6-tert-butyl-2-methylphenol),
4,4'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4-benzyloxy-4'-hydroxydiphenyl sulfone, 4,4'-diphenol sulfoxide, P-hydroxybenzoic acid isopropyl, P -Benzyl hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1,7-bis (4-hydroxyphenylthio) -3,
5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -propane, 1,3-bis (4-hydroxyphenylthio) ) -2-Hydroxypropane, N, N'-diphenylthiourea, N, N'-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, 2-hydroxy-3-naphthoic acid, 2 -Hydroxy-1
-Naphthoic acid, 1-hydroxy-2-naphthoic acid, metal salts of hydroxynaphthoic acid such as zinc, aluminum and calcium, bis- (4-hydroxyphenyl) acetic acid methyl ester, bis- (4-hydroxyphenyl) acetic acid benzyl ester , 1,3-bis (4-hydroxycumyl) benzene, 1,4
-Bis (4-hydroxycumyl) benzene, 2,4'-diphenol sulfone, 3,3'-diallyl-4,4'-diphenol sulfone, α, α-bis (4-hydroxyphenyl) -α- Methyltoluene, zinc thiocyanate antipyrine complex,
Tetrabromobisphenol A, tetrabromobisphenol S, 4,4'-thiobis (2-methylphenol), 4,4'-
Thiobis (2-chlorophenol) etc.

In order to produce the heat-sensitive recording material of the present invention,
When the leuco dye and the color developer are bound and supported on the support, various commonly used binders can be appropriately used, and specific examples thereof include the following.

Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose and ethyl cellulose, polyacrylic acid sodium -Da, polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, styrene /
Maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, soda alginate, gelatin, other water-soluble polymers such as casein, polyvinyl acetate, polyurethane, polyacrylic acid, Polyacrylic acid ester, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene /
Emulsion such as vinyl acetate copolymer, latex such as styrene / butadiene copolymer and styrene / butadiene / acrylic copolymer.

In the present invention, various heat-fusible substances can be used as the sensitivity improver, and specific examples thereof include the followings, but the present invention is not limited thereto. . Fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, fatty acid metal salts such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate and zinc behenate, p-benzyl Biphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, phenyl β-naphthoate, phenyl 1-hydroxy-2-naphthoate, methyl 1-hydroxy-2-naphthoate, diphenyl Carbonate, Greacol Carbonate, Dibenzyl terephthalate, Dimethyl terephthalate, 1,4-Dimethoxynaphthalene, 1,4-Diethoxynaphthalene, 1,4-Dibenzyloxynaphthalene, 1,2-Diphenoxyethane, 1,2 -
Bis (3-methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-diphenoxy-2-butene, 1,2-
Bis (4-methoxyphenylthio) ethane, dibenzoylmethane, 1,4-diphenylthiobutane, 1,4-diphenylthio
-2-butene, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- (2
-Vinyloxyethoxy) bifer, p-aryloxypphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, dibenzoyloxypropane, dibenzyl disulfide, 1,1-diphenylethanol, 1,1-diphenylpropanol, p -Benzyloxybenzyl alcohol, 1,3-phenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-
Octadecylcarbamoylbenzene, 1,2-bis (4-methoxyphenoxy) propane, 1,5-bis (4-methoxyphenoxy) -3-oxapentane, dibenzyl oxalate, bis (4-methylbenzyl) oxalate, oxalic acid Bis (4-chlorobenzyl) and the like.

In the case of obtaining a heat-sensitive recording material according to the present invention, if necessary, an additive component commonly used in this kind of heat-sensitive recording material, such as a leuco dye, a color developer and an inorganic filler containing the above-mentioned ultraviolet absorber, is used. A filler, a surfactant and the like can be used in combination. In this case, as a filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, other inorganic fine powder such as surface-treated calcium or silica, Examples thereof include urea-formalin resin, styrene-methacrylic acid copolymer, polystyrene resin, vinylidene chloride resin, and other organic fine powders.

[0024]

EXAMPLES Next, the present invention will be described in more detail by way of examples. All parts and% shown below are based on weight.

Examples 1 to 3 [Solution A] 3-dibutylamino-6-methyl-7-anilinofluorane 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts water 60 parts [Solution B] 4-isopropoxy-4 ′ -Hydroxydiphenyl sulfone 10 parts Polyvinyl alcohol 10% aqueous solution 25 parts Water 50 parts [C liquid] 20 parts UV absorbing filler described in Table 1 Polyvinyl alcohol 10% aqueous solution 20 parts Water 60 parts Each of the above mixtures in a magnetic ball mill. Were pulverized for 2 days to prepare [A solution], [B solution] and [C solution]. Next, 10 parts of [Solution A], 30 parts of [Solution B], 30 parts of [Solution C] and 10 parts of 20% aqueous solution of isobutylene / maleic anhydride copolymer were mixed to prepare a thermosensitive recording layer forming liquid.
This was coated and dried on a high-quality paper having a basis weight of 50 m ² / g so that the amount of dye adhering after drying was 0.5 m ² / g, and a thermosensitive recording layer was provided to prepare a thermosensitive color-coated paper. Next, the following mixture was stirred to prepare a protective layer forming liquid [D liquid]. [Solution D] 10% aqueous solution of polyvinyl alcohol 25 parts Silica gel 12 parts 10% aqueous solution of water-proofing agent 10 parts Water 88 parts Next, the amount of adhesion after drying on the above-mentioned paper coated with the thermosensitive recording layer becomes 3 m ² / g. Applied to the surface and dried to give a surface smoothness of 500
A thermosensitive recording material was prepared by calendering for about 600 seconds.

Examples 4 to 6 The same as Examples 1 to 3 except that the following [Solution E] was used in place of [Solution C] and the following [Solution E] was used in place of [Solution D]. Then, a thermal recording material was prepared. [Solution E] Silica gel 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [Solution F] 10% aqueous solution of polyvinyl alcohol 20 parts Ultraviolet absorbing filler described in Table 1 1.2 parts 10% aqueous solution of water resistant agent 10 parts Water 8.8 parts

Examples 7 to 9 After the thermosensitive recording layer was formed in the same manner as in Examples 4 to 6, the following intermediate layer forming liquid [G liquid] was used to dry the paper on which the thermosensitive recording layer was coated. A protective layer was formed so that the amount of adhesion would be 1 g / m ² to prepare a heat-sensitive recording material. [Solution G] 10% aqueous solution of polyvinyl alcohol 30 parts UV absorbing filler shown in Table 1 2 parts water 18 parts

Comparative Example 1 In Examples 1 to 3, instead of [C liquid], [E]
Liquid was used to prepare a heat-sensitive recording material in the same manner.

Comparative Example 2 A thermosensitive recording material was prepared in the same manner as in Examples 1 to 3 except that the following [H liquid] was used instead of [C liquid]. [Liquid H] Aluminum hydroxide 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts About the heat-sensitive recording material obtained as described above, using a thermal gradient tester manufactured by Toyo Seiki Seisakusho, temperature 150 ° C, pressure 2 kg /
Printed under the condition of m ² , 1 second, and the image density and background density were determined by Macbeth densitometer RD914 (filter W-106).
And the value was used as the pre-test concentration. Next, a light resistance test was conducted as shown below. Light resistance: The image obtained by the test of the dynamic color development sensitivity was measured with a weather meter C165 manufactured by Toyo Seiki Co., Ltd. with a Xe lamp of 0.35.
After irradiation with w / m ² for 24 hours, the densities of the image area and the background area were measured with a Macbeth densitometer RD-914 (filter W106). The test results are shown in Table 1.

[0030]

[Table 1] From the results in Table 1, it can be seen that the heat-sensitive recording material of the present invention has excellent light resistance in the image area and the background area.

[0031]

The heat-sensitive recording material of the present invention has excellent light resistance in the image area and the background area, and is extremely easy to manufacture and has excellent workability.

Claims (3)

[Claims] 1. A heat-sensitive recording layer containing a leuco dye and a color developer which develops a color when the leuco dye is contacted as a main component is provided on a support, and a protective layer is further provided on the heat-sensitive recording layer and a protective layer and a heat-sensitive recording layer. A heat-sensitive recording material having an intermediate layer provided between the intermediate layer, the heat-sensitive recording layer and the protective layer containing an inorganic filler having an ultraviolet absorber adsorbed on the surface thereof. material. 2. The heat-sensitive recording material according to claim 1, wherein the inorganic filler for adsorbing the ultraviolet absorber has a specific surface area of 200 m ² / g or more. 3. The heat-sensitive recording material according to claim 1, wherein the absorption end of the ultraviolet absorber to be adsorbed on the surface of the inorganic filler is on the longer wavelength side than 400 nm.