JP2804334B2 - Thermosensitive coloring composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermosensitive coloring composition. More specifically, the present invention relates to an organic solvent-dispersed thermosensitive coloring composition having good dispersibility to provide a thermosensitive recording sheet having excellent coloring properties without coating unevenness.

2. Description of the Related Art A thermosensitive recording material in which a leuco dye such as crystal violet lactone and a phenolic compound such as bisphenol A are coated on a support with a vehicle or the like is characterized in that there is no generation of noise, off-flavor, smoke or the like during recording. Widely used in the field of information equipment, such as printing with a thermal printer used as a terminal such as an electronic computer, recording with a thermal pen recorder for various medical devices such as electrocardiogram, recording with a printer of industrial measuring equipment, or recording with a thermal facsimile Have been.

In recent years, its use has been expanded by taking advantage of its features, such as application to ticket papers such as commuter passes and coupons, cards and labels. And the demand for thermosensitive recording materials is 1
It has been changed from one-time use (recording) to one that can withstand many uses, and the support of thermal recording materials has been changed from paper to plastic film or synthetic paper with good mechanical strength and water resistance. Conversion is desired.

On the other hand, means for forming a heat-sensitive recording color-forming layer on a support include not only a full-surface coating method (coating) as found in heat-sensitive facsimile paper and recording paper for printers in main application fields, but also partial printing using a conventional printing machine. Printing methods such as printing and pattern printing have begun to be used. In these methods, the coating conditions, particularly the thickness of the coating layer, vary depending on the coating or printing method.In order to obtain the adaptability of the coating amount in any of these methods, the concentration of the thermosensitive coloring component must be adjusted. It is necessary to keep it high.

Conventionally, in preparing a heat-sensitive coating liquid, dispersing in an organic solvent system, that is, a color-developing compound and a color-forming compound were separately dissolved in an organic solvent or a resin (polymer compound) serving as a binder was dissolved. In the case of such dispersion, when the solid concentration is increased, the viscosity increases and gelation occurs, and not only a good dispersion is not obtained, but also a coating is performed. During processing or printing, the density of a recorded image that has developed due to uneven streaks or spots tends to be insufficient.

PROBLEM TO BE SOLVED BY THE INVENTION An organic solvent-dispersed thermosensitive coloring composition having good dispersibility for providing a thermosensitive sheet excellent in coloring properties without coating unevenness is desired.

Means for Solving the Problems The present inventors have made various studies to improve the above-described problems, and as a result, have completed the present invention.

That is, the present invention provides a thermosensitive coloring composition in which a color-developing compound and a color-forming compound that reacts with the color-developing compound under heating to form a color are dispersed in a vehicle mainly composed of an organic solvent and a polymer compound. An object of the present invention is to provide a thermosensitive color-forming composition characterized by containing an octadecylmonoamidodiisobutylene maleate copolymer.

The heat-sensitive color-forming composition of the present invention is a chromium-forming compound, a color-developing compound, a polymer compound, a filler, a heat-fusible compound, if necessary, an octadecyl monoamide diisobutylene maleate copolymer in an organic solvent. It is obtained by mixing and dispersing together with other additives. It is preferable that the color-forming compound and the color-developing compound are separately pulverized and dispersed, and mixed in a necessary amount immediately before coating or printing.

The octadecyl monoamide diisobutylene maleate copolymer used in the present invention exhibits an action as a dispersant, and the amount of the dispersant used is 0.05% by weight or more in the thermosensitive coloring composition to be dispersed. 20%, preferably 0.1
% To 5%.

Specific examples of the organic solvent, polymer compound, color-forming compound, color-developing compound, and other additives for preparing the composition of the present invention include the following.

Aromatic hydrocarbons as organic solvents for vehicle formation,
Naphthenic hydrocarbons and paraffinic hydrocarbons are used alone or as a mixture.

Examples of aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, ethyltoluene and the like, and mixtures thereof. Among them, it is preferable to use toluene and / or xylene. Examples of naphthenic hydrocarbons include silopentane, methylcyclopentane, 1,1-dimethylcyclopentane, 1,3-dimethylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, 1,2,4-trimethylcyclohexane, and the like. Of these, it is preferable to use cyclohexane and / or ethylcyclohexane. Examples of paraffinic hydrocarbons include n-hexane, n-heptane, n-octane, n-nanone, isomers thereof, and mixtures thereof. When used as a mixed solvent, the solvent used as the main component is, for example, in the range of 80 to 140 ° C for a gravure printing (or coating) composition, or 140 ° C to 200 ° C for a screen printing (or coating) composition.
Those having a boiling point in the range of ° C. are preferred.

As the polymer compound, those which are soluble in the organic solvent to be used and give vehicle formation and film formation are used, and specific examples thereof include polyvinyl chloride, polyacryl, polyester,
Examples thereof include polycarbonate, polyurethane, polybutyral, epoxy resin, furan resin, vinyl toluene copolymer, and rosin ester resin. These polymer compounds are contained in the composition in an amount of 1 to 20% by weight, preferably 3 to 10% by weight.

 Examples of the color-forming compound include the following.

Rhodamine-β-anilinolactam, rhodamine (p-nitroanilino) lactam, 2-dibenzylamino-6-diethylaminofluoran, 2-anilino-3-methyl-6-diethylamino-fluoran, 2-anilino as xanthene compounds -3-methyl-6-cyclohexylmethylaminofluoran, 2-anilino-3-
Methyl-6-isobentylethylaminofluoran, 2
-Anilino-3-methyl-6-dibutylaminofluoran, 2-p-chloroanilino-3-methyl-6-diethylaminofluoran, 2-p-fluoroaniline-3-
Methyl-6-diethylaminofluoran, 2-p-fluoroanilino-3-methyl-6-dibutylaminofluoran, 2-anilino-3-methyl-6- (p-toluidinoethyl) aminofluoran, 2-p -Toluidino-3
-Methyl-6-diethylaminofluoran, 2-o-chloroanilino-6-diethylaminofluoran, 2-o
-Chloroanilino-6-dibutylaminofluoran, 2
-O-fluoroanilino-6-diethylaminofluoran, 2-o-fluoroanilino-6-dibutylaminofluoran, 2-m-chloroanilino-6-diethylaminofluoran, 2-anilino-3-methyl-6 -Piperidinofluoran, 2-anilino-3-methyl-6-pyrrolidinofluoran, 2-m-trifluoromethylanilino-6-diethylaminofluoran, 2-dihexylamino-6-aminofluoran, 2 -Butylamino-3-
Chloro-6-diethylaminofluoran, 2-ethoxyethylamino-3-chloro-6-diethylaminofluoran, 2-anilino-3-chloro-6-diethylaminofluoran, 2-diphenylamino-6-diethylaminofluoran, 2- Anilino-3-methyl-6-diphenylaminofluoran, 2-phenyl-6-diethylaminofluoran, 2-chloro-3-methyl-6-diethylaminofluoran, 2-chloro-6-diethylaminofluoran, 2- Methyl-6-diethylaminofluoran, 6-diethylamino-1,2-benzfluoran and the like,
3,3-bis (p-
Dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-
Bis (p-dimethylaminophenyl) phthalide, 3-
(P-dimethylaminophenyl) -3- (1,2-dimethylaminoindol-3-yl) phthalide, 3- (p-
3-methyl-3-spirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-benzylspirodinaphthopyran as spiropyran-based compounds such as dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide and chromenes Methyl-naphtho- (3-methoxy-benzo) spiropyran,
3-propyl-spirodibenzopyran, 1,3,3-trimethyl-6'-nitro-8'-methoxyspiro (indoline-2,2'-benzopyran), 1,3,3-trimethyl-
4,4'-bis-dimethylaminobenzhydrin benzyl ether as a diphenylmethane compound such as 6'-nitrospiro (indoline-2,2'-benzopyran);
N-halophenyl-leuco auramine, N-2,4,5-trichlorophenyl leuco auramine and the like, benzoyl leucomethylene blue and p-nitrobenzyl leuco methyl len blue as thiazine compounds, and other bis-3 , 3- [Bis-1,1- (p-dimethylaminophenyl) ethyleno-2] phthalide, bis-3,3- [bis-
1,1- (p-dimethylaminophenyl) ethyleno-2]
-4,5,6,7-tetrachlorophthalide, bis-3,3- [bis-1,1 (p-diethylaminophenyl) ethylene-2]
-4,5,6,7-tetrachlorophthalide, bis-3,3- [bis-1,1- (p-dimethylaminophenyl) ethyleno-
2] phthalide derivatives containing a divinyl group such as -4 (or 7) -nitrophthalide, 3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6'-dimethylaminophthalide, 3,6-bis Fluorene compounds such as (diethylamino) fluorenespiro (9,3 ')-6'-diethylaminophthalide can also be used. These coloring compounds are used alone or in combination.

Examples of the color-developing compound include α-naphthol, β-naphthol, p-octylphenol, 4-t-octylphenol, p-t-butylphenol, p-phenylphenol, and 1,1′-bis (p-octylphenol). (Hydroxyphenyl) propane, 2,2'-bis (p-hydroxyphenyl) propane, 2,2'-bis (p-hydroxyphenyl) butane, 1,1'-bis (p-hydroxyphenyl) cyclohexane , 4,4'-thiobisphenol, 4,4'-cyclo-
Hexylidenediphenol, 4,4'-sulfonyldiphenol, 4,4'-sulfonyl-bis (2-allylphenol), 2,2-bis (2,5-dibromo-4-hydroxyphenyl) propane, 4 , 4'-isopropylidenebis (2
-T-butylphenol), 2,2'-methylenebis (4
Phenolic compounds such as -chlorophenol), benzyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, dibenzyl 4-hydroxyphthalate, dimethyl 4-hydroxyphthalate, ethyl 5-hydroxyisophthalate, 3,5-t Aromatic carboxylic acid derivatives such as -butylsalicylic acid and 3,5-di-α-methylbenzylsalicylic acid; aromatic carboxylic acids or polyvalent metal salts thereof; These color-forming compounds and color-developing compounds are contained in the composition in a total amount of 1 to 40% by weight, preferably 10 to 30% by weight.

 Examples of other additives used as needed are given below.

Examples of the filler include calcium carbonate, magnesium magnesium, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydride, aluminum hydride, aluminum oxide, barium sulfate, polystyrene resin, urea-formalin resin and the like. .

Examples of the heat-fusible compound include waxes such as animal and vegetable waxes, polyethylene waxes and synthetic waxes, higher fatty acids, higher fatty acid amides, higher fatty acid metal salts, acetylated aromatic amino compounds, aromatic ether compounds, and biphenyl derivatives. And a solid having a melting point of about 80 ° C. or higher.

Other zinc stearate, calcium stearate,
Lubricants such as aluminum stearate, various surfactants, antifoaming agents and the like are added as necessary.

The thermosensitive color-forming composition of the present invention is prepared using the above-mentioned materials by, for example, the following method.

First, a color-forming compound and a color-developing compound are separately pulverized using a dispersing machine such as a ball mill attritor and a sand mill together with the octadecyl monoamide diisobutylene maleate copolymer and the polymer compound and other additives in the above-mentioned organic solvent. After dispersing, mixing so that the ratio of the coloring compound and the developing compound is usually 1: 1 to 1:10 by dry weight ratio,
Further, if necessary, a polymer compound solution and other additives are added to obtain the thermosensitive color-forming ink composition of the present invention.

The thermosensitive coloring composition of the present invention is a paper, a plastic sheet, a synthetic paper, a bar coater on a support such as a fiber sheet,
It can be applied by a usual coating method using a roll coater, a reverse coater, a doctor coater or the like, and can also be printed by a method such as gravure, letterpress, flexily or silk screen. The heat-sensitive recording layer is usually formed as a coating of 0.5 to 10 g / m ^{2 on} a dry weight basis. Dispersion composition (or fluidity) of the color-forming compound or the color-developing compound of the present invention using octadecylmonoamidodiisobutylene maleate copolymer and the thermosensitive color-forming composition prepared using the same as the main component Is good, and the thermosensitive recording layer formed on the support by means such as coating or printing has excellent thermosensitive coloring property (coloring density).

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. `` Parts '' in the examples
Indicates parts by weight.

Example 1 A mixture having the following composition was pulverized for 1 hour using a sand mill,
By dispersing, compositions [A] and [B] were obtained.

Composition [A]: 4,4'-sulfonyl-bis (2-allylphenol) 40.0 parts Octadecylmonoamide maleate-diisobutylene copolymer 0.5 part Toluene 59.5 parts Composition [B]: 2-o-fluoroanilino -6-Diethylaminofluorane 40.0 parts Octadecylmonoamide maleate-diisobutylene copolymer 0.5 part Toluene 59.5 parts Next, the mixture was mixed at the following mixing ratio to obtain a thermosensitive coloring composition of the present invention.

Thermosensitive coloring composition: 10 parts of composition [A]: 30 parts of composition [B] 20 parts of a toluene solution of a 20% methacryl-styrene copolymer (molecular weight: about 100,000, Tg point: 128 ° C) 20 parts Toluene 20 parts Place the composition on a milky white polyester sheet for 20 minutes.
g / m ^{2 was} applied and dried to obtain a thermosensitive coloring sheet.

Example 2 A mixture having the following composition was pulverized for 1 hour using a sand mill,
By dispersing, compositions [C] and [D] were obtained.

Composition [C]: 2,2-bis (p-hydroxyphenyl) propane 40 parts Octadecylmonoamide maleate-diisobutylene copolymer 2 parts Xylene 58 parts Composition [D]: 2-o-fluoroanilino-6 -Diethylaminofluorane 40 parts Octadecylmonoamide maleate-diisobutylene copolymer 2 parts Xylene 58 parts Next, the mixture was mixed at the following mixing ratio to obtain a thermosensitive color-forming composition of the present invention.

Thermosensitive coloring composition: 10 parts of composition [C]: 30 parts of composition [D] 20 parts xylene solution of methacryl-styrene copolymer (molecular weight: about 100,000, Tg point: 128 ° C) 20 parts xylene 20 parts Place the composition on a milky white polyester sheet for 20 minutes.
g / m ^{2 was} applied and dried to obtain a thermosensitive coloring sheet.

Comparative Example 1. A comparative thermosensitive coloring composition was prepared in the same manner as in Example 1 except that the octadecylmonoamide maleate-diisobutylene copolymer was not used, and a thermosensitive coloring sheet was produced.

Comparative Example 2 A comparative thermosensitive coloring composition was prepared in the same manner as in Example 2 except that the octadecylmonoamide maleate-diisobutylene copolymer was not used, and a thermosensitive coloring sheet was produced.

A quality test was carried out using these heat-sensitive coloring compositions of the present invention and comparative examples and the heat-sensitive coloring sheets obtained therefrom.

1) Fluidity The fluid state when the container holding the dispersion liquid was tilted was examined.

○: flowing △: flowing slowly ×: little or no movement 2) Color density Density printing of a thermosensitive coloring sheet made with a commercially available thermal printer (D-805P, manufactured by Ishida Koki)
The color density was measured by a Macbeth reflection densitometer RD-914.

3) Unevenness of coating The coated part of the prepared thermosensitive coloring sheet was observed, and the presence or absence of bumps, spots, and streaks was examined.

：: almost or not at all △: somewhat noticeable ×: frequently observed As is clear from the above quality tests, the thermosensitive coloring composition of the present invention has good fluidity, and the thermosensitive coloring properties prepared therefrom. The coating finish of the sheet is good and the coloring density is high.

Effects of the Invention A thermosensitive coloring composition which has good fluidity, hardly causes uneven coating, and facilitates preparation of a thermosensitive sheet having a high coloring density is obtained.

Claims (1)

(57) [Claims] 1. A thermosensitive coloring composition obtained by dispersing a color-developing compound and a color-forming compound which reacts with the color-developing compound under heating and forms a color in a vehicle mainly comprising an organic solvent and a polymer compound. 3. The thermosensitive color-forming composition according to claim 1, further comprising an octadecylmonoamide diisobutylene maleate copolymer.