JPH0986047A - Thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal recording material excellent not only in water resistance and printability but also in running properities at a time of recording. SOLUTION: In a thermal recording material wherein a thermal recording layer containing a colorless or light-colored basic dye and a coupler is provided on a support and a productive layer is provided thereon, the thermal recording layer and the protective layer contain an org. amine neutralized substance of a silicone containing graft copolymer having a carboxyl group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material which is excellent in water resistance and printability as well as running property during recording.

[0002]

2. Description of the Related Art A heat-sensitive recording material which utilizes a color reaction between a colorless or pale basic dye and an organic or inorganic color agent to bring both color-forming substances into contact with each other by heat to obtain a color-developed image is often used. Are known. Since such a thermal recording material is relatively inexpensive and the recording equipment is compact and its maintenance is relatively easy, it is used not only as a recording medium for facsimiles and various computers but also in a wide range of fields.

As one of the fields of use thereof, a recording medium for a handy terminal is drawing attention. Such a handy terminal is often used outdoors, and the problem is that the recording surface gets wet and peels off in rainy weather. Further, in applications such as handy terminals, offset printing is performed on the recording surface, so that there is an increasing demand for a thermal recording material having excellent printability.

Conventionally, for the purpose of improving the water resistance of the heat-sensitive recording layer, a material having a water-proofing agent added to the heat-sensitive recording layer or the one described in Japanese Patent Application Laid-Open No.
49-36343 and JP-A-54-133352), there are those in which a hydrophobic polymer emulsion is used as an adhesive in the thermosensitive recording layer (JP-A-57-14998, 57-18520). The present situation is that a recording layer excellent in water resistance, printability and running property has not yet been obtained. Further, JP-A-6-247048 discloses a thermosensitive recording medium containing a water-soluble graft copolymer of a polymer containing a carboxylic acid and a silicone in the thermosensitive layer and the protective layer. However, since these copolymers are neutral salts of sodium, potassium or ammonium salts,
In the case of sodium salt or potassium salt, there is a problem that the water resistance is poor, and in the case of ammonium salt, there is a problem that the ground color is likely to occur because it easily reacts with the color developing agent,
It did not yet have sufficient performance.

Further, a protective layer containing a water-soluble polymer compound is provided for the purpose of solving the problem that the recorded color image is erased when it comes into contact with moisture, fingerprints, hand cream or plastic such as vinyl chloride resin. It has been proposed to provide it on the thermosensitive recording layer. When such a protective layer is provided, it is possible to prevent the color-recorded image from being erased and to improve the problems such as sticking, head shavings and scratches, but the water resistance and printability are extremely poor. was there.

[0006]

DISCLOSURE OF THE INVENTION The present inventors have solved the above-mentioned problems and, in particular, have sufficient strength such as water resistance (for example, the surface of a thermosensitive recording medium does not peel off even when wet). And a printability (for example, a part of the surface of the recording material is not peeled off by printing) and a heat-sensitive recording material excellent in running property at the time of recording were studied. is there.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a semiconductor device comprising the steps of:
A heat-sensitive recording material having a heat-sensitive recording layer containing a colorless or light-colored basic dye and a coloring agent, and further having a protective layer thereon, wherein the heat-sensitive recording layer and the protective layer have a carboxyl group-containing silicone-containing graft. It is a heat-sensitive recording material containing an organic amine neutralized product of a copolymer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

-Organic amine neutralized product of carboxyl group-containing silicone-containing graft copolymer In the thermosensitive recording medium of the present invention, organic amine neutralized product of carboxyl group-containing silicone-containing graft copolymer contained in the thermosensitive recording layer and protective layer. Various substances can be used as (hereinafter, referred to as a graft copolymer neutralized product). As the graft copolymer neutralized product, a silicone-based macromonomer having an ethylenically unsaturated group, an ethylenically unsaturated carboxylic acid, and, if necessary, a carboxyl group by polymerization with other radically polymerizable monomer are included. It is preferable that the silicone-containing graft copolymer is reacted with an organic amine to form a salt.

The silicone-containing macromonomer having an ethylenically unsaturated group at one end is a dialkylpolysiloxane such as dimethylpolysiloxane or diethylpolysiloxane having an ethylenically unsaturated group at one end, and a diphenylpolysiloxane compound. Etc., and the (meth) acryloyl group is preferable as the ethylenically unsaturated group. Specific examples of the ethylenically unsaturated carboxylic acid include:
For example, (meth) acrylic acid, itaconic acid, crotonic acid,
Examples include fumaric acid and maleic acid. Other radically polymerizable monomers include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate and 2-ethylhexyl (meth) acrylate,
(Meth) such as 2-hydroxyethyl (meth) acrylate
Examples thereof include hydroxyalkyl acrylate and styrene.

The silicone-containing macromonomer having an ethylenically unsaturated group at one end with respect to the ethylenically unsaturated carboxylic acid is preferably 5 to 50% by weight, more preferably 10 to 30% by weight. If this ratio is less than 5% by weight, the water resistance of the recording layer may not be obtained, while if it exceeds 50% by weight, the adhesive strength may decrease.

In the present invention, the organic amine for neutralizing the silicone-containing graft copolymer having a carboxyl group is triethylamine, diisopropylamine, monoethanolamine, triethanolamine,
Primary, secondary or tertiary amine compounds such as diisopropanolamine and dimethylethanolamine, and heterosubstituted amine compounds such as pyridine and pyreridine are preferred.

Thermal Sensitive Recording Layer The present invention comprises the above-mentioned neutralized graft copolymer in the thermal sensitive recording layer. The content of the graft copolymer neutralized product in the thermosensitive recording layer is not particularly limited, but is preferably 1 to 15% by weight of the solid content forming the thermosensitive recording layer. If the content is less than 1% by weight, a sufficient water resistance improving effect may not be obtained, while if it exceeds 15% by weight, the color-forming component may be reduced, resulting in a decrease in color-forming sensitivity.

In addition to the graft copolymer neutralized product, the heat-sensitive recording layer may contain a binder in an amount such that water resistance and printability are not impaired. Examples of the binder include starches such as oxidized starch, enzyme-modified starch, cation-modified starch, esterified starch and etherified starch, cellulose derivatives such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, methoxy cellulose and hydroxyethyl cellulose, complete or incomplete saponification. Polyvinyl alcohols such as polyvinyl alcohol, carboxy-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol and acetoacetyl group-modified polyvinyl alcohol, sodium polyacrylate, polyacrylamide,
Polyvinylpyrrolidone, acrylic acid amide / acrylic acid ester copolymer, acrylic acid amide / acrylic acid ester / methacrylic acid copolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, Water-soluble polymers such as sodium alginate, gelatin and casein, as well as polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic acid ester, polybutyl methacrylate, styrene / butadiene copolymer, vinyl chloride / vinyl acetate copolymer, ethylene -Latexes of vinyl acetate copolymers and styrene-butadiene-acrylic copolymers and the like can be mentioned.

As the colorless or light-colored basic dye contained in the heat-sensitive recording layer, various kinds can be used, for example,
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2)
-Methylphenyl) -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-dibenzylamino-benzo [a] fluorane,
3- (N-ethyl-Np-tolyl) amino-7-N-
Methylanilinofluorane, 3-diethylamino-7-
Anilinofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3,6-bis (diethylamino) fluorane-γ-anilinolactam, 3-cyclohexylamino-6-chlorofluorane, 3-diethylamino-6- Methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane, 3- (N-ethyl-
N-isoamyl) amino-6-methyl-7-anilinofluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3- (N-methyl-N
-Cyclohexyl) amino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di (n-butyl) amino-6-
Methyl-7-anilinofluorane, 3-di (n-pentyl) amino-6-methyl-7-anilinofluorane, 3
-Diethylamino-7- (o-chlorophenylamino)
Fluorane, 3-di (n-butyl) amino-7- (o-
Chlorophenylamino) fluorane, 3-diethylamino-7- (o-fluorophenylamino) fluorane,
3-di (n-butyl) amino-7- (o-fluorophenylamino) fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3-
(N-ethyl-p-toluidino) -6-methyl-7-
(P-Toluidino) fluorane, 3- (N-ethyl-N)
-Furfurylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3- (N-methyl-Nn-propylamino) -6-methyl -7-Anilinofluorane, 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-anilinoanilino) anilino-6-methyl-7-chlorofluorane, 2,2-bis {4- [6 '-(N-cyclohexyl-N-methyl Amino) -3'-methylspiro [phthalide-3,9'-xanthen-2'-ylamino] phenyl} propane, 3,6, -bis (dimethylamino) fluorene-9-spiro-3 '-(6'-dimethyl) amino)
Phthalide and the like. Two or more kinds of these basic dyes can be used in combination, if necessary.

Various compounds can be used as the colorant (acidic substance) used in combination with the basic dye, and there are inorganic acidic substances and organic acidic substances. As the inorganic acidic substance, activated clay,
Attapulgite, colloidal silica, aluminum silicate and the like can be mentioned. Moreover, as an organic acidic substance, 4-
Cumylphenol, hydroquinone monobenzyl ether, 4,4'-isopropylidenediphenol, 1,1
-Bis (4-hydroxyphenyl) cyclohexane,
4,4'-dihydroxydiphenyl-2,2-butane,
4,4'-dihydroxydiphenylmethane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane,
2,2-bis (4-hydroxyphenyl) heptane, bis (4-hydroxyphenylthioethoxy) methane,
1,5-di (4-hydroxyphenylthio) -3-oxapentane, 1,1-bis (4-hydroxyphenyl)
-1-phenylethane, 1,4-bis [α-methyl-α
-(4'-hydroxyphenyl) ethyl] benzene,
1,3-bis [α-methyl-α- (4′-hydroxyphenyl) ethyl] benzene, 4,4′-dihydroxydiphenyl sulfide, bis (4-hydroxy-3-methylphenyl) sulfide, 4,4′- Dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4 -Hydroxyphenyl-4'-benzyloxyphenyl sulfone, 4-hydroxy-3 ',
4'-tetramethylene biphenyl sulfone, 3,4-dihydroxyphenyl-p-tolyl sulfone, 4-hydroxybenzoic acid benzyl ester, bis (p-hydroxyphenyl) acetate butyl, bis (p-hydroxyphenyl) acetate methyl, (4 -Hydroxyphenylthio) acetic acid-2- (4-hydroxyphenylthio) ethyl ester, di (p-hydroxyphenylthioethyl) ether, N, N'-di-m-chlorophenylthiourea and N
Phenolic compounds such as-(phenoxyethyl) -4-hydroxyphenylsulfonamide, 4- [2- (p-
Methoxyphenoxy) ethyloxy] salicylic acid, 4-
Aromatic carboxylic acids such as {3- (p-tolylsulfonyl) propyloxy] salicylic acid, 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylic acid and p-chlorobenzoic acid; Examples thereof include salts with polyvalent metals such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin and nickel, and antipyrine complexes of zinc thiocyanate.

In the present invention, the use ratio of the basic dye and the color developing agent in the heat-sensitive recording layer may be appropriately selected according to the types of the basic dye and the color developing agent used, and is not particularly limited. However, 1 to 1 part by weight of the basic dye contains 1 to 1
The amount is preferably 50 parts by weight, more preferably 2 to 10 parts by weight.

The heat-sensitive recording layer is a neutralized product of the graft copolymer,
A coating solution for a heat-sensitive recording layer, which comprises a basic dye, a color-developing agent and other substances, is prepared, coated on a support and dried. As a method for preparing the coating liquid for the heat-sensitive recording layer, for example, water is used as a dispersion medium, and a color former and a color former and other substances are used together or separately using a pulverizer such as a ball mill, an attritor or a sand mill. Examples include a method of pulverizing, adding a neutralized product of the graft copolymer to the mixture, and dispersing the mixture with a stirrer. If necessary, various auxiliary agents can be added to the coating liquid. Examples of the dispersant include sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate and fatty acid metal salt, stearic acid. Zinc, calcium stearate, polyethylene wax, carnauba wax,
Waxes such as paraffin wax and ester wax, antifoaming agents, fluorescent dyes, and coloring dyes are added as appropriate.

It is also possible to use various pigments in combination in the coating liquid, for example, kaolin, clay, calcium carbonate, calcined clay, calcined kaolin, titanium oxide, diatomaceous earth,
Inorganic pigments such as fine particulate anhydrous silica and activated clay, organic pigments such as styrene microballs, nylon powder, polyethylene powder, urea / formalin resin fillers, raw starch particles and polystyrene fillers can be mentioned.

Further, a sensitizer may be used in the coating solution depending on the purpose. Specific examples of the sensitizer include, for example, stearic acid amide, methoxycarbonyl-N-stearic acid benzamide, N-benzoylstearic acid amide, N-eicosanoic acid amide, ethylenebistearic acid amide, behenic acid amide, and methylenebisstearic acid. Amide, N-methylolstearic acid amide, dibenzyl terephthalate, dimethyl terephthalate, dioctyl terephthalate, benzyl p-benzyloxybenzoate,
Phenyl 1-hydroxy-2-naphthoate, 2-naphthylbenzyl ether, m-terphenyl, dibenzyl oxalate, oxalate-di-p-methylbenzyl, oxalate-di-p-chlorobenzyl, p-benzylbiphenyl,
Triryl biphenyl 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- (2-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, 1,4-di (phenylthio) butane, p-acetotoluidide, p-acetophenetizide, N-acetoacetyl-p-toluidine, di ( β
-Biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-isopropylphenyl-2
-Phenylethane and the like are exemplified. The amount of these sensitizers used is not particularly limited, but it is generally desirable to adjust the amount within the range of about 4 parts by weight or less relative to 1 part by weight of the color developing agent.

In order to further improve the storage stability of recorded images,
It is also possible to use a preservative improving agent in an amount that does not impair the heat-sensitive effect. Specific examples of such storage improvers include 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-ethylenebis (4-methyl-6-tert-butylphenol) 2. 2'-methylenebis (4-ethyl-6-tert-butylphenol),
2,2'-methylenebis (4,6-di-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-
tert-butylphenol), 2,2'-ethylidene bis (4-methyl-6-tert-butylphenol), 2,
2'-ethylidene bis (4-ethyl-6-tert-butylphenol), 2,2 '-(2,2-propylidene) bis (4,6-di-tert-butylphenol), 2,2'
-Methylenebis (4-methoxy-6-tert-butylphenol), 2,2'-methylenebis (6-tert-butylphenol), 4,4'-thiobis (3-methyl-6-
tert-butylphenol), 4,4'-thiobis (2-
Methyl-6-tert-butylphenol), 4,4'-thiobis (5-methyl-6-tert-butylphenol),
4,4'-thiobis (2-chloro-6-tert-butylphenol), 4,4'-thiobis (2-methoxy-6-
tert-butylphenol), 4,4'-thiobis (2-
Ethyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tert-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'-tetrabromodiphenyl sulfone, 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) Hindered phenol compounds such as propane, N, N'-di-2-naphthyl-p
-Phenylenediamine, 2,2'-methylenebis (4,
6-di-tert-butylphenyl) sodium phosphate, 4,
Ethyleneimine compounds such as 4'-bis (ethyleneiminecarbonylamino) diphenylmethane, 1,4-diglycidyloxybenzene, 4,4'-diglycidyloxydiphenylsulfone, terephthalic acid diglycidyl ether, 4-benzyloxyphenyl- Epoxy compounds such as 4 '-(2-methyl-2,3-epoxypropyloxy) phenyl sulfone and novolac type resins can be used.

Protective Layer The thermosensitive recording medium of the present invention has a protective layer provided on the thermosensitive recording layer. With such a structure, sticking and head residue are improved, and storage stability of recording is improved. Can be improved. If sticking is poor, the recorded image will be affected, and if the print length becomes shorter than it should be, or if solid black recording is performed, the unprinted part will be a white line at right angles to the paper feed direction. In some cases, there is a problem such as the occurrence of problems.

In the present invention, the protective layer contains a graft copolymer neutralized product. When the protective layer contains the neutralized product of the graft copolymer, it is possible to obtain a heat-sensitive recording material which is extremely excellent in running property during recording, water resistance and printability.

The content of the neutralized product of the graft copolymer in the protective layer is not particularly limited, but it is usually preferable to add it in an amount of about 5 to 50% by weight based on the total solid content of the protective layer. If this ratio is less than 5% by weight, sufficient water resistance improving effect may not be obtained, and if it exceeds 50% by weight, writability and imprintability may be slightly deteriorated.

In addition to the graft copolymer neutralized product, the protective layer may contain a binder in an amount that does not impair the water resistance and printability. As a specific example, the binder used in the heat-sensitive recording layer was used. The same thing can be used. Further, in order to further improve printability and sticking, a pigment can be added as necessary. Specific examples thereof include:
Calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, silicon dioxide, aluminum hydroxide, barium sulfate, zinc sulfate, talc, kaolin, clay, calcined clay, calcined kaolin, fine anhydrous silica, colloidal silica, diatomaceous earth and activated clay. And inorganic pigments, and organic pigments such as styrene microballs, nylon powder, polyethylene powder, urea / formalin resin filler and raw starch particles. It is generally desirable to adjust the amount used in the range of about 5 to 300 parts by weight with respect to 100 parts by weight of the binder component.

For the protective layer, for example, water is used as a dispersion medium, a neutralization product of the graft copolymer, a binder and a pigment are mixed to prepare a coating solution for the protective layer, which is coated on the thermosensitive recording layer and dried. Let it form. In the protective layer coating liquid, if necessary, zinc stearate, calcium stearate,
Lubricants such as polyethylene wax, carnauba wax, paraffin wax and ester wax, surfactants (dispersant, wetting agent) such as sodium dioctylsulfosuccinate, antifoaming agents, and water-soluble polyvalent metal salts such as potassium alum and aluminum acetate. It is also possible to add various auxiliary agents as appropriate. Further, a curing agent such as glyoxal, boric acid, dialdehyde starch, or an epoxy compound can be used in combination for further improving the water resistance.

Heat Sensitive Recording Material The method of manufacturing the heat sensitive recording material is not particularly limited, and examples thereof include air knife coating, varibar blade coating, pure blade coating,
By a suitable coating method such as rod blade coating, short dwell coating, curtain coating or die coating, the heat sensitive recording layer coating liquid is applied onto the support and dried, and then the protective layer coating liquid is applied and dried. And the like. As the support, various materials can be used, and examples thereof include paper, plastic film, synthetic paper, non-woven fabric and metal vapor deposition. As the coating amount of the heat-sensitive recording layer coating solution is preferably 1~12g / m ² by dry weight, more preferably from 2 to 6 g / m ^2. The coating amount of the protective layer coating liquid is 0.1 to 20 g / dry weight.
m ² is preferable, and more preferably 0.5 to 4 g / m ² .

If desired, a protective layer may be provided on the back side of the thermosensitive recording medium to further improve the storability. Furthermore, an undercoat layer may be provided on the support, smoothing treatment such as supercalendering may be applied after each layer is smeared to improve image quality and image density, or an adhesive label may be applied to the back surface of the recording material to form an adhesive label. If necessary, various known techniques in the field of manufacturing a thermal recording medium, such as providing a magnetic layer on the back surface of the thermal recording medium, can be added.

[0028]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. Further, unless otherwise specified, the parts and% in each example represent parts by weight and% by weight, respectively.

Example 1 Formation of Thermosensitive Recording Layer 1) Preparation of Solution A 10 parts of a basic dye, 3-di (n-butyl) amino-6-methyl-7-anilinofluorane, and a sensitizer 1, 2-
A composition consisting of 15 parts of di (3-methylphenoxy) ethane, 15 parts of a 5% aqueous solution of methylcellulose as a binder and 80 parts of water was pulverized with a sand mill until the average particle diameter became 1 μm. 2) Preparation of solution B A composition consisting of 30 parts of 4-hydroxy-4′-isopropoxydiphenylsulfone as a coloring agent, 30 parts of a 5% aqueous solution of methylcellulose as a binder and 70 parts of water has an average particle diameter of 2 μm in a sand mill. Crushed until. 3) Preparation of Neutralized Product of Graft Copolymer 20 parts of a silicone-containing macromonomer having a methacryloyl group at one end, 15 parts of methacrylic acid, 25 parts of methyl methacrylate and 40 parts of butyl methacrylate are copolymerized to obtain a carboxyl group obtained. The obtained silicone-containing graft copolymer was treated with dimethylethanolamine to obtain a graft copolymer neutralized product. 4) Preparation of coating liquid for heat-sensitive recording layer 25% aqueous solution of the graft copolymer neutralized product obtained above 50
Parts, 120 parts of solution A, 130 parts of solution B, 10 parts of fine particulate anhydrous silica and 5 parts of light calcium carbonate, 10 parts of a 30% dispersion of zinc stearate as an auxiliary agent, and 20 parts of water are stirred and mixed. To prepare a coating liquid for the heat-sensitive recording layer. 5) Formation of heat-sensitive recording layer The obtained heat-sensitive recording layer coating liquid was applied to high-quality paper having a basis weight of 45 g / m ² so that the coating amount after drying was 4 g / m ² to form a recording layer. did.

Formation of Protective Layer 1) Preparation of Coating Liquid for Protective Layer 50 parts of 25% aqueous solution of the graft copolymer neutralized product obtained in 3) above, 20 parts of pigmented anhydrous silica and light calcium carbonate 5 parts, 30% of zinc stearate as an auxiliary agent
10 parts of the dispersion liquid and 60 parts of water were stirred and mixed to prepare a coating liquid for protective layer. 2) Formation of protective layer The obtained coating liquid for protective layer was applied onto the heat-sensitive recording layer obtained above,
After coating and drying so that the coating amount after drying was 1 g / m ² , super calendering treatment was carried out to obtain a thermosensitive recording paper.

Example 2 Preparation of Graft Copolymer Neutralized Product 30 parts of a silicone-containing macromonomer having a methacryloyl group at one end, 10 parts of acrylic acid, 30 styrene
Parts, 2-ethylhexyl methacrylate 15 parts and 2-
Copolymerize 15 parts of hydroxyethyl methacrylate,
The obtained silicone-containing graft copolymer having a carboxyl group was treated with triethylamine to obtain a neutralized graft copolymer. Preparation of thermal recording paper Instead of 50 parts of 25% aqueous solution of the graft copolymer neutralized product used in Example 1, 50 parts of 25% aqueous solution of the graft copolymer neutralized product obtained above was used. Example 1 except
In the same manner as described above, a thermosensitive recording paper was obtained.

Example 3 Preparation of Neutralized Graft Copolymer 20 parts of silicone-containing macromonomer having methacryloyl group at one end, 15 parts of maleic anhydride, 4 styrene
5 parts and 20 parts of butyl methacrylate were copolymerized, and the obtained silicone-containing graft copolymer having a carboxyl group was treated with triethanolamine to obtain a neutralized product of the graft copolymer. Preparation of thermal recording paper Instead of 50 parts of 25% aqueous solution of the neutralized graft copolymer used in Example 1, 40 parts of 25% aqueous solution of the neutralized graft copolymer obtained above and silicon-modified polyvinyl Example 1 except 25 parts of a 10% aqueous solution of alcohol were used
In the same manner as described above, a thermosensitive recording paper was obtained.

Comparative Example 1 Preparation of Graft Copolymer Neutralized Product 20 parts of a silicone-containing macromonomer having a methacryloyl group at one end and 80 parts of acrylic acid were copolymerized,
The obtained silicone-containing graft copolymer having a carboxyl group was treated with sodium hydroxide to obtain a sodium salt neutralized product of the graft copolymer. Preparation of thermal recording paper except that 50 parts of a 25% aqueous solution of the graft copolymer neutralized product used in Example 1 was replaced with 50 parts of a 25% aqueous solution of the sodium salt of the graft copolymer obtained above. In the same manner as in Example 1, a thermal recording paper was obtained.

Comparative Example 2 Preparation of Neutralized Graft Copolymer Copolymerization of 30 parts of a silicone-containing macromonomer having a methacryloyl group at one end and 70 parts of methacrylic acid, the resulting graft copolymer having a carboxyl group The polymer was treated with ammonia to obtain the ammonium salt of the graft copolymer. Preparation of thermal recording paper, except that 50 parts of a 25% aqueous solution of the neutralized graft copolymer used in Example 1 was replaced with 50 parts of a 25% aqueous solution of the ammonium salt of the graft copolymer obtained above. Is
A thermal recording paper was obtained in the same manner as in Example 1.

The following five evaluation tests were carried out on the five types of thermal recording papers thus obtained. Table 1 shows the results. 1) Recording density Using a thermal recording simulator [TH-PDM, made by Okura Electric Co., Ltd.], recording with an applied head energy of 0.3 mJ / dot,
The density of the obtained recorded image was measured with a Macbeth densitometer [RD914, manufactured by Macbeth Co.].

2) Printability Using 0.4 cc of ink for offrin (tack value: 13),
Printing was performed with an RI type printing tester manufactured by Akira Seisakusho, and after passing through a water roll, printing was performed using a roll with ink, and the peeled state of the heat-sensitive recording layer was visually evaluated.

[Evaluation Criteria] A ... No peeling of the thermosensitive recording layer is observed. ◯: The thermal recording layer was slightly peeled off. Δ: The thermal recording layer was slightly peeled off. ×: Peeling of the heat-sensitive recording layer was very large.

3) Water resistance The recording surface was immersed in water at room temperature, pulled up after 1 hour, and rubbed 100 times with a finger to visually judge the degree of peeling of the recording surface. O: Almost no peeling of the recording surface. △: The recording surface was slightly peeled off. X: The recording surface is often peeled off.

5) Travelability In the method of 1) above, the applied head energy is 0.5 m.
Recording was performed in the same manner by increasing to J / dot, and running performance was evaluated by the loudness of sound (sticking sound) generated during recording. ◎ ・ ・ ・ ・ ・ The running performance is very good. O: Good running performance. × ・ ・ ・ Drivability is poor

6) Ground color development The heat-sensitive recording paper was evaluated for whiteness after standing at 60 ° C and 90% humidity for 24 hours. ○: Almost the same as before the test. ×: Change from white to gray.

[0041]

[Table 1]

[0042]

The thermosensitive recording medium of the present invention is excellent in water resistance and printability, and is excellent in running property during recording.

Claims (1)

[Claims] 1. A thermosensitive recording medium having a thermosensitive recording layer containing a colorless or light-colored basic dye and a coloring agent on a support, and further having a protective layer thereon, wherein the thermosensitive recording layer and the protective layer are provided. A heat-sensitive recording material, wherein the layer contains an organic amine neutralized product of a silicone-containing graft copolymer having a carboxyl group.