JP2003312145A - Heat-sensitive color developable composition and heat- sensitive recording material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a heat-sensitive color developable composition having excellent coating properties and antiseptic sterilizability of a coating liquid, and to develop a heat-sensitive recording material coating the composition on a support and drying the composition. <P>SOLUTION: The heat-sensitive color developable composition contains a normally colorless or pale color developable compound and a developable compound capable of heating time color developing the color developable compound as essential components on a support. The composition further contains at least one type of a water soluble thickening polysaccharide polymer compound and at least one type of antiseptics or a bactericide. The heat-sensitive recording material contains the heat-sensitive color developable composition coating on the support and drying. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermosensitive color-developing composition and a thermosensitive recording material using the same. More specifically, it relates to a thermosensitive color-developing composition excellent in coating properties and antiseptic / sterilizing properties of coating liquids, and a thermosensitive recording material obtained by coating the composition on a support and drying the composition.

[0002]

2. Description of the Related Art Generally, a heat-sensitive recording material is prepared by separately dispersing a leuco dye and a color developing agent such as a phenolic substance in the form of fine particles and mixing them together, and then adding a binder, a sensitizer, a filler and a lubricant. It is applied as a coating liquid by adding additives such as etc. to paper, film, synthetic paper, etc., and color recording is made by a chemical reaction that occurs when one or both of the leuco dye and the developer melts and is heated by heating. I will get it. A thermal printer or the like having a built-in thermal head is used for coloring the heat-sensitive recording sheet. Compared with other recording methods, this thermal recording method has (1) no noise during recording, (2) no need for development and fixing, (3) maintenance-free, (4) relatively inexpensive machine By the characteristics such as
Facsimile field, computer output, calculator field printer field, medical measurement recorder field,
It is widely used in the fields of automatic ticket vending machines and heat-sensitive recording labels.

In recent years, along with the introduction of POS systems in retail stores and supermarkets and automation systems in transportation facilities, applications such as applications to labels, tickets, coupons, cards, etc. have expanded, and thermal recording Not only paper but also plastic films, which have excellent surface uniformity and good mechanical strength and water resistance, and synthetic papers are increasing in number, and the range of materials that can be used as a support is expanding. Therefore, the thermosensitive color-forming composition (ink or paint) used for forming the thermosensitive color-recording layer on these supports is increasingly required to have coating properties suitable for the supports. Many of these compositions are dispersions using water as a medium, and the use of a thickener has been proposed as one method for improving coatability, but when a water-soluble thickening polysaccharide polymer compound is used. Is
Due to its nature, it is apt to cause the problem of spoilage, which requires great care in production and storage / management of the coating liquid, and there is still nothing to be satisfied.

[0004]

The objects of the present invention are as follows.
It is to solve the drawbacks of the prior art. That is, it is intended to provide a thermosensitive color-developing composition excellent in coating properties and antiseptic / sterilizing properties of coating liquids, and a thermosensitive recording material obtained by coating the composition on a support and drying the composition.

[0005]

The present inventors have completed the present invention as a result of various studies to achieve the above object. That is, the present invention relates to (1) a thermosensitive color-developing composition comprising, as a main component, a color-forming compound which is usually colorless or light-colored on a support, and a color-developing compound capable of coloring the color-forming compound when heated. (2) a preservative or a thermosensitive color-forming composition, characterized in that the color-forming composition contains at least one water-soluble thickening polysaccharide polymer compound and at least one preservative or bactericide. At least one of the bactericides is an isothiazoline compound or a salt thereof, and the thermosensitive coloring composition according to (1), (3) at least one of the preservatives or bactericides is 1,2-benzisothiazoline-3-. The present invention relates to a thermosensitive color-forming composition described in (2) which is on, and (4) a thermosensitive recording material obtained by applying the thermosensitive color-forming composition described in (1) to (3) on a support and drying.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-sensitive color-forming composition and heat-sensitive recording material according to the present invention are usually colorless or light-colored color-forming compound and a color-developing compound capable of forming a color when the color-forming compound is heated, and at least one water-soluble compound. The main components are a high-viscosity polysaccharide polymer compound and at least one preservative or bactericide. In the present invention, the water-soluble thickening polysaccharide polymer compound functions as a thickener or a dispersant stabilizer, but if necessary, a sensitizer (heat-fusible compound) or a bond as shown below may be added. Agents, fillers, other lubricants,
The thermosensitive color-developing composition is prepared by using additives such as a surfactant, a defoaming agent and an ultraviolet absorber together.

In the thermosensitive color-forming composition of the present invention, the color-forming compound is usually contained in an amount of 1 to 50% by weight, preferably 5 to 30% by weight, and the color-developing compound is usually contained in an amount of 1 to 8%, respectively.
0% by weight, preferably 5 to 40% by weight, water-soluble thickening polysaccharide polymer compound is usually 0.001 to 3% by weight, preferably 0.005 to 0.2% by weight, preservative or bactericide Is usually 0.01 to 1% by weight, preferably 0.03
~ 0.3% by weight, sensitizer (heat-fusible compound), binder,
The filler is usually 0 to 80% by weight, other lubricants, surfactants, defoaming agents, ultraviolet absorbers and the like in arbitrary proportions,
For example, it is usually used in an amount of 0 to 30% by weight (% by weight is the weight ratio of each component in the thermosensitive coloring layer). In a further preferred embodiment, among the above-mentioned compositions, the color developing compound is usually 0.5 to 20 times, preferably 0.5 to 20 times, by weight of the composition ratio relating to the basic color forming property. 1 to
The water-soluble thickening polysaccharide polymer compound acting as a thickener or dispersant stabilizer, and the preservative or bactericide are 5 times as much as the weight ratio in the thermosensitive color-forming composition, and the water-solubility is high. The thickening polysaccharide polymer compound is preferably 0.005 to 0.2% by weight, and the preservative or bactericide is
It is preferably used in the range of 0.03 to 0.3% by weight.

The water-soluble thickening polysaccharide polymer compound used as a thickener or dispersant stabilizer in the present invention includes, for example, xanthan gum, rhamzan gum, welan gum, gellan gum, guar gum and its derivatives, carboxymethyl cellulose (CMC), Cellulose derivatives such as hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC), hydroxypropyl cellulose (HPC) and ethyl cellulose (EC), sodium alginate, carrageenan, locust bean gum, pectin and the like are mentioned, and particularly preferable ones are Examples include xanthan gum, rhamsan gum, welan gum, gellan gum, guar gum and its derivatives. The water-soluble thickening polysaccharide polymer compound used in the present invention can be obtained from the market, and examples thereof include trade names: Kelzan (manufactured by CP KELCO), Jaguar (manufactured by Rhodia), and the like. These water-soluble thickening polysaccharide polymer compounds are used alone or as a mixture.

The preservatives or bactericides that can be used in the present invention include, for example, organic nitrogen type, organic sulfur type, organic nitrogen sulfur type, organic halogen type, haloallyl sulfone type, iodopropargyl type, N-haloalkylthio type, Benzthiazole-based, Nitotyryl-based, Pyridine-based, 8-oxyquinoline-based, Benzothiazole-based, Isothiazoline-based, Dithiol-based, Pyridine oxydide-based, Nitropropane-based, Organotin-based, Phenol-based, Quaternary ammonium salt-based, Triazine-based, Thiadiazine Examples thereof include compounds such as compounds based on anilide, adamantane, dithiocarbamate, brominated indanone, benzyl bromacetate, and inorganic salts, with isothiazoline compounds being preferred. Examples of the isothiazoline-based compound include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5- Chloro-2-methyl-4
-Isothiazolin-3-one magnesium chloride,
5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride and the like can be mentioned, more preferably 1,2-benzisothiazolin-3-one. is there. This is CAS. No. It is a known compound registered in Chemical Abstracts as 2634-33-5 and can be obtained from the market. These preservatives or bactericides may be used alone or in combination.

Specific examples of the color forming compound that can be used include:
There is no particular limitation as long as it is one generally used for pressure-sensitive recording paper and heat-sensitive recording paper. Specific examples include, for example, fluoran compounds, triarylmethane compounds,
Examples thereof include spiro compounds, diphenylmethane compounds, thiazine compounds, lactam compounds, fluorene compounds, and the like.

Specific examples of the fluorane compound include 3-diethylamino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane and 3- (N-methyl). -N-cyclohexylamino) -6-methyl-7-anilinofluorane, 3
-(N-ethyl-N-isopentylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-
Isobutylamino) -6-methyl-7-anilinofluorane, 3- [N-ethyl-N- (3-ethoxypropyl) amino] -6-methyl-7-anilinofluorane,
3- (N-ethyl-N-hexylamino) -6-methyl-7-anilinofluorane, 3-dipentylamino-6
-Methyl-7-anilinofluorane, 3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-N-tetrahydrofurylamino) -6- Methyl-7-anilinofluorane, 3-
Diethylamino-6-methyl-7- (p-chloroanilino) fluorane, 3-diethylamino-6-methyl-7
-(P-Fluoroanilino) fluorane, 3- [N-ethyl-N- (p-tolyl) amino] -6-methyl-7-
Anilinofluorane, 3-diethylamino-6-methyl-7- (p-toluidino) fluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3 -Diethylamino-7- (o-fluoroanilino) fluorane, 3-dibutylamino-7- (o-fluoroanilino) fluorane, 3-diethylamino-7-
(3,4-Dichloroanilino) fluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7-ethoxyethylaminofluorane, 3-diethylamino-6-chloro- 7-anilinofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane,
3-diethylamino-7-octylfluorane, 3-
[N-ethyl-N- (p-tolyl) amino] -6-methyl-7-phenethylfluorane and the like can be mentioned.

Specific examples of triarylmethane compounds include, for example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone or CVL) and 3,3-bis ( p
-Dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylaminoindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methyl Indole-3-
Yl) phthalide, 3- (p-dimethylaminophenyl)
-3- (2-phenylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindole-3-
Yl) -5-dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -5-dimethylaminophthalide,
3,3- (2-phenylindol-3-yl) -5-
Examples thereof include dimethylaminophthalide and 3-p-dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide.

Specific examples of the spiro compounds include, for example, 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylspirodinaphthopyran, 3- Propyl spirobenzopyran, 3-methylnaphtho- (3-methoxybenzo) spiropyran, 1,3,3-trimethyl-6
-Nitro-8'-methoxyspiro (indoline-2,
2'-benzopyran) and the like are specific examples of the diphenylmethane compound, for example, N-halophenyl-leuco auramine, 4,4-bis-dimethylaminophenylbenzhydrylbenzyl ether, N-2,4,5-triene. Chlorophenyl leuco auramine and the like are specific examples of thiazine compounds such as benzoyl leuco methylene blue and p-nitrobenzoyl leuco methylene blue, and specific examples of lactam compounds are, for example, rhodamine B anilinolactam and rhodamine B-p. -Chloroanilinolactam and the like are specific examples of the fluorene-based compound, for example, 3,6-bis (dimethylamino) fluorene spiro (9,3 ')-6'-dimethylaminophthalide, 3,6-bis ( Dimethylamino) fluorenspyrro (9,3 ′)-6′-pyrroli Nofutarido, 3-dimethylamino-6-diethylamino fluorene spiro (9,
3 ')-6'-pyrrolidinophthalide and the like, respectively. These color forming compounds may be used alone or as a mixture.

As the color-developing compound, any of those generally used for pressure-sensitive recording paper and heat-sensitive recording paper can be used, for example, α-naphthol, β-naphthol, p-octylphenol, 4-t-. Octylphenol, p-
t-butylphenol, p-phenylphenol, 1,
1-bis (p-hydroxyphenyl) propane, 2,2
-Bis- (p-hydroxyphenyl) propane (alias:
Bisphenol A or BPA), 2,2-bis- (p-
Hydroxyphenyl) butane, 1,1-bis- (p-hydroxyphenyl) cyclohexane, 4,4′-thiobisphenol, 4,4′-cyclo-hexylidenediphenol, 2,2′-bis- (2,5 -Dibromo-4-hydroxyphenyl) propane, 4,4'-isopropylidenebis (2-t-butylphenol), 2,2'-methylenebis (4-chlorophenol), 4,4'-dihydroxydiphenylsulfone, 2, 4'-dihydroxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, bis (4-hydroxyphenyl) methyl acetate, bis (4-hydroxyphenyl)
Phenolic compounds such as butyl acetate, bis (4-hydroxyphenyl) benzyl acetate, benzyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, dibenzyl 4-hydroxyphthalate, dimethyl 4-hydroxyphthalate, 5-hydroxyisophthalate Aromatic carboxylic acid derivatives such as ethyl acidate, 3,5-di-t-butylsalicylic acid and 3.5-di-α-methylbenzylsalicylic acid, aromatic carboxylic acids or polyvalent metal salts thereof, etc. Examples of the color-developing compound used include those used for heat-sensitive recording paper and heat-sensitive recording paper, but are not limited thereto.

Specific examples of sensitizers (heat-fusible compounds) that can be used in the present invention as required include waxes such as animal and vegetable waxes and synthetic waxes, higher fatty acids, higher fatty acid amides and higher fatty acid anilides. , Naphthalene derivatives, aromatic ethers, aromatic carboxylic acid derivatives,
Aromatic sulfonic acid ester derivatives, carbonic acid or oxalic acid diester derivatives, biphenyl derivatives, terphenyl derivatives, sulfone derivatives and the like that are solid at room temperature and have a melting point of about 70 ° C. or higher can be used.

Specific examples of waxes that can be used in the present invention as needed include wood wax, carnauba wax, shellac, paraffin, montan wax, oxidized paraffin, polyethylene wax, polyethylene oxide, and the like. Specific examples of higher fatty acid amides include stearic acid amide, oleic acid amide, and N.
-Methylstearic acid amide, erucic acid amide, methylol behenic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, and the like. Specific examples of higher fatty acid anilides include, for example, stearic acid anilide, linoleic acid anilide, and naphthalene. Specific examples of the derivative include 1-benzyloxynaphthalene and 2
-Benzyloxynaphthalene, 1-hydroxynaphthoic acid phenyl ester and the like are specific examples of the aromatic ether such as 1,2-diphenoxyethane, 1,4-diphenoxybutane and 1,2-bis (3-methyl). Phenoxy) ethane, 1,2-bis (4-methoxyphenoxy)
Ethane, 1,2-bis (3,4-dimethylphenyl) ethane, 1-phenoxy-2- (4-chlorophenoxy)
Ethane, 1-phenoxy-2- (4-methoxyphenoxy) ethane, 1,2-bis (phenoxymethyl) benzene and the like are specific examples of the aromatic carboxylic acid derivative, for example, p-hydroxybenzoic acid benzyl ester, p -Benzyloxybenzoic acid benzyl ester, terephthalic acid dibenzyl ester and the like are specific examples of the aromatic sulfonic acid ester derivative, for example, p-toluenesulfonic acid phenyl ester, phenylmesitylene sulfonate,
Specific examples of carbonic acid or oxalic acid diester derivatives such as 4-methylphenylmesitylene sulfonate include carbonic acid diphenyl, oxalic acid dibenzyl ester, oxalic acid di (4-chlorobenzyl) ester, and oxalic acid di (4-methyl). Specific examples of the biphenyl derivative include, for example, p-benzylbiphenyl,
Specific examples of the terphenyl derivative include p-allyloxybiphenyl and the like, for example, m-terphenyl and the like, and specific examples of the sulfone derivative include, for example, diphenylsulfone and the like. These sensitizers may be used alone or as a mixture, if necessary.

Specific examples of the binder that can be used in the present invention as required include, for example, methyl cellulose, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, cellulose, polyvinyl alcohol (PV.
A), carboxyl group-modified polyvinyl alcohol, sulfonic acid group-modified polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, starch and its derivatives, casein, gelatin, water-soluble isoprene rubber, alkali of styrene / maleic anhydride copolymer Salts, water-soluble substances such as alkali salts of iso (or diiso) butylene / maleic anhydride copolymers, polyvinyl acetate, vinyl chloride / vinyl acetate copolymers, polystyrene,
Polyacrylic acid ester, polyurethane, styrene / butadiene (SB) copolymer, carboxylated styrene /
Examples thereof include a butadiene (SB) copolymer, an ethylene / acrylic acid copolymer, a styrene / butadiene / acrylic acid copolymer, and a hydrophobic polymer emulsion such as colloidal silica / acrylic resin composite particles. These binders may be used alone or as a mixture, if necessary.

Specific examples of the filler that can be used in the present invention as required include, for example, calcium carbonate, magnesium carbonate, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydroxide,
Examples thereof include aluminum hydroxide, aluminum oxide, barium sulfate, polystyrene resin and urea-formalin resin. These fillers may be used alone or as a mixture, if necessary.

Other additives include higher fatty acid metal salts such as zinc stearate and calcium stearate for the purpose of preventing thermal head abrasion and sticking, and phenol derivatives for imparting antioxidant or aging preventing effects. , UV absorbers such as benzophenone-based compounds and benzotriazole-based compounds, various surfactants, defoaming agents and the like are used as necessary.

The thermosensitive color-developing composition and the thermosensitive recording material of the present invention are prepared using the above-mentioned materials, for example, by the following method. That is, according to a conventional method, first, a color-forming compound, a color-developing compound, and optionally a sensitizer (heat-fusible compound) are separately added together with a binder or, if necessary, other additives, etc. in a ball mill or attritor. After crushing and dispersing with a disperser such as a sand mill (water is usually used as a medium when crushing and dispersing are performed in a wet state), at least one water-soluble thickening polysaccharide polymer is added to each dispersion. The compound and at least one preservative or bactericidal agent are usually mixed in a ratio in the range described in the present invention to prepare a thermosensitive color developing layer coating solution to obtain the thermosensitive color forming composition of the present invention.

Next, the heat-sensitive recording material of the present invention will be described. The heat-sensitive recording material of the present invention is obtained by coating the above-mentioned heat-sensitive color-forming composition of the present invention on a support such as paper, plastic sheet and synthetic paper by a conventional method. in this case,
For coating, a bar coater, a blade coater, a roll coater, a reverse coater, a doctor coater, a micro gravure coater, etc. can be used for coating by an ordinary coating method, and printing by a method such as gravure, letterpress, flexo, or silk screen is also possible. After coating, the heat-sensitive recording material of the present invention can be obtained by drying by a conventional method such as air drying (normal temperature) or hot air drying up to about 150 ° C. The heat-sensitive recording layer is usually formed on the support as a coating film having a dry weight of 0.5-20 g / m ² . In the heat-sensitive recording material of the present invention, an intermediate layer may be provided between the heat-sensitive color developing layer and the support, or an overcoat layer (protective layer) may be provided on the heat-sensitive color developing layer, if necessary. The intermediate layer and the overcoat layer (protective layer) are pulverized and dispersed together with a binder and, if necessary, other additives in the same manner as in the preparation of the coating solution for the thermosensitive color developing layer. Layer) After being made into a coating solution, it is applied so that the dry weight thereof is usually about 0.1 to 10 g / m ² .

Usually, a colorless or light-colored color-forming compound, a color-developing compound capable of coloring the color-forming compound when heated, at least one water-soluble thickening polysaccharide polymer compound, and at least one preservative or sterilizer. The thermosensitive color-developing composition of the present invention containing an agent is excellent in stabilizing the quality in the manufacturing process as compared with the conventionally known ones, and has good coatability and antiseptic properties of the coating liquid.
It has excellent bactericidal properties and storability, and is coated on a support and dried,
A heat sensitive recording material can be obtained.

[0023]

EXAMPLES The present invention will be described in more detail by way of examples, but the present invention is not limited thereto. In the examples, "part" indicates part by weight.

Example 1 (Preparation of Coloring Agent Composition Liquid [A]) A mixture of the following compositions excluding 1% xanthan gum aqueous solution and 33% 1,2-benzisothiazolin-3-one aqueous dispersion was placed in a sand grinder. It is pulverized and dispersed so that the average particle diameter becomes 1 μm or less, and then 1% xanthan gum aqueous solution, 33
% 1,2-benzisothiazolin-3-one aqueous dispersion was stirred and mixed to prepare color former composition liquid [A]. Liquid [A]: 3-dibutylamino-6-methyl-7-anilinofluorane 7 parts 1,2-bis (phenoxymethyl) benzene 21 parts 25% PVA aqueous solution 20 parts water 50 parts 1% xanthan gum aqueous solution 2 parts 33 % 1,2-Benzisothiazolin-3-one aqueous dispersion (preparation of developer composition liquid [B]) 1% xanthan gum aqueous solution, 33% 1,2-benzisothiazoline-3 -On water dispersion, 50% calcium carbonate water dispersion, and a mixture excluding 50% carboxylated styrene / butadiene copolymer latex are pulverized and dispersed using a sand grinder so that the average particle diameter is 1 μm or less. After that, 1% xanthan gum aqueous solution, 33% 1,
2-benzisothiazolin-3-one aqueous dispersion, 50%
An aqueous dispersion of calcium carbonate and a 50% carboxylated styrene / butadiene copolymer latex were stirred and mixed to prepare a developer composition liquid [B]. Liquid [B]: 4,4′-dihydroxydiphenyl sulfone 14 parts 25% PVA aqueous solution 20 parts water 29 parts 50% calcium carbonate aqueous dispersion 20 parts 50% carboxylated styrene / butadiene copolymer latex 15 parts 1% xanthan gum aqueous solution 2 parts 33% 1,2-benzisothiazolin-3-one aqueous dispersion 0.1 part (formation of thermosensitive coloring layer) Then, the following proportions were mixed to obtain a thermosensitive coloring composition of the present invention. Coloring agent composition liquid [A] liquid 50 parts Coloring agent composition liquid [B] liquid 50 parts Next, this thermosensitive color developing composition has a basis weight of 50 g / m ² and a dry weight of 8 g / m ^2. To obtain a thermosensitive coloring layer. (Formation of Protective Layer) Further, a protective layer coating solution [C] having the following composition ratio was applied onto the thermosensitive color developing layer in an amount of 3 when dried.
The heat-sensitive recording material of the present invention having a protective layer was obtained by coating so as to be g / m ² and drying. Liquid [C]: 40% styrene / acrylic ester copolymer emulsion 20 parts 5% bentonite aqueous dispersion 40 parts 30% zinc stearate aqueous dispersion 3 parts

Example 2 A thermosensitive recording material of the present invention with a protective layer was obtained in the same manner as in Example 1 except that 2 parts of a 1% guar gum aqueous solution was used instead of 2 parts of a 1% xanthan gum aqueous solution. It was

Example 3 Instead of 3-dibutylamino-6-methyl-7-anilinofluorane, 3-dipentylamino-6-methyl-
A heat-sensitive recording material of the present invention with a protective layer was obtained in the same manner as in Example 1 except that 7-anilinofluorane was used.

Example 4 The invention of the present invention with a protective layer was carried out in the same manner as in Example 1 except that bis (3-allyl-4-hydroxyphenyl) sulfone was used instead of 4,4'-dihydroxydiphenylsulfone. A thermosensitive recording material was obtained.

Example 5 Instead of 33% 1,2-benzisothiazolin-3-one aqueous dispersion, 5-chloro-2-methyl-4-isothiazolin-3-one and 2-bromo-2-nitropropane were used. A thermal recording material of the present invention with a protective layer was obtained in the same manner as in Example 1 except that 0.2 part of the mixed dispersion of -1,3-diol was used.

Example 6 Instead of 33% 1,2-benzisothiazolin-3-one aqueous dispersion, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride and 2-methyl-4- A heat-sensitive recording material of the present invention with a protective layer was obtained in the same manner as in Example 1 except that 0.2 part of a 3: 1 mixed dispersion of isothiazolin-3-one calcium chloride was used.

Comparative Example 1 A thermosensitive color-forming composition for comparison was prepared and carried out in the same manner as in Example 1 except that 33% 1,2-benzisothiazolin-3-one aqueous dispersion was not used. A thermal recording material for comparison having a protective layer was obtained in the same manner as in Example 1.

Comparative Example 2 A thermosensitive coloring composition for comparison was obtained in the same manner as in Example 1 except that 1% xanthan gum aqueous solution was not used. A thermal recording material for comparison was obtained.

Table 1 shows the quality performances of the thermosensitive color-developing composition and the thermosensitive recording material of the present invention and comparative examples obtained as described above.

[0033] Table 1 Quality performance test                Background 1) Color density 2) Heat resistance 3) Example 1 0.05 1.57 1.57 Example 2 0.05 1.54 1.54 Example 3 0.05 1.57 1.55 Example 4 0.04 1.70 1.70 Example 5 0.05 1.55 1.56 Example 6 0.05 1.56 1.56 Comparative Example 1 0.04 1.53 1.52 Comparative Example 2 0.04 1.53 1.52

[0034]  Table 1 (continued)             Antiseptic / sterilizing properties 4) Coating properties 5) Preservation properties 6) Example 1 ○ ○ ○ Example 2 ○ ○ ○ Example 3 ○ ○ ○ Example 4 ○ ○ ○ Example 5 ○ ○ ○ Example 6 ○ ○ ○ Comparative Example 1 × ○ ○ Comparative Example 2 ○ △ ×

1) Background: A value measured by a Macbeth reflection densitometer RD-914 type (Macbeth reflection density) in the uncolored portion of the sample. 2) Color density: Macbeth reflection density value of the image portion printed by a thermal printer (D-805P) manufactured by Ishida Co., Ltd. 3) Heat resistance: 6 samples of color developed by the above printer
Macbeth reflection density of the image portion after standing in a 0 ° C incubator for 24 hours. 4) Antiseptic / bactericidal property: Bacteria present in the liquid obtained by washing the container prepared with the thermosensitive color-developing composition of the present invention are cultivated to obtain the color-developing composition liquid [A] and the color-developing composition liquid [B]. Add to the inside of a liquid food and use a simple quantitative culture medium food plate for bacteria (for general viable cell count and coliform test, manufactured by Meguro Research Institute) to 3
The test was conducted at 7 ° C. for 24 hours. ◯: Effective x: Inadequate effect 5) Coating property: The state during coating (viscosity of coating liquid, coating unevenness) is visually evaluated. ◯: Good Δ: Partially uneven X: Poor 6) Storability: 1 kg of each of the color former composition liquid [A] and the developer composition liquid [B] for the present invention for comparison and for comparison in a 1 L plastic bottle. It was put in, sealed, and allowed to stand in a thermostat at 40 ° C. for 1 month, and then the presence or absence of sediment was evaluated. ○: No sedimentation ×: Sedimentation

As is apparent from the table, the thermosensitive color-developing composition of the present invention is excellent in coating property, antiseptic / sterilizing property of the coating liquid and storability, and the heat-sensitive recording material has whiteness of the background and coloring density. Are better.

[0037]

EFFECTS OF THE INVENTION A thermosensitive color-developing composition having excellent coating properties and antiseptic / sterilizing properties of coating liquids, and coating the same on a support,
A dried thermosensitive recording material was obtained.

Continued front page    (72) Inventor Yosuke Tsugawa             2010-2 Mabashi, Matsudo City, Chiba Prefecture F term (reference) 2H026 AA07 BB02 BB24 CC07 DD01                       DD12 DD46 DD53 FF01

Claims (4)

[Claims] 1. A thermosensitive color-forming composition comprising, as a main component, a color-forming compound which is usually colorless or light-colored on a support, and a color-developing compound capable of color-forming the color-forming compound when heated. A thermosensitive color-developing composition, characterized in that it contains at least one water-soluble thickening polysaccharide polymer compound and at least one preservative or bactericide. 2. At least one preservative or bactericide is an isothiazoline compound or a salt thereof.
The heat-sensitive color-forming composition as described in 1. 3. The thermosensitive color-developing composition according to claim 2, wherein at least one preservative or bactericide is 1,2-benzisothiazolin-3-one. 4. A heat-sensitive recording material obtained by applying the heat-sensitive color-forming composition according to claim 1 on a support and drying the composition.