JPH10100543A - Heat-sensitive coloring composition and thermal recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-sensitive color recording material (sheet) which is excellent in coloring properties and preservability. SOLUTION: In a heat-sensitive coloring composition wherein a color developing compound, a coloring compound coloring by reaction under heating with the color developing compound, and macromolecular compound are dispersed in organic solvent, the heat-sensitive coloring composition contains 2-(0- fluoroanilino)-6-diethyl-aminofluoran or 2-(0-chloroanilino)-6-diethylamino-fluoran as the coloring compound, and a compound of the following formula as the color developing composition, and a thermal recording material is provided wherein the abovementioned composition is applied onto a base material and dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive coloring composition and a thermosensitive recording material. More specifically, the present invention relates to an organic solvent-dispersed thermosensitive coloring composition having excellent coloring properties and storage stability, and a thermosensitive recording material obtained by applying and drying the composition.

[0002]

2. Description of the Related Art Generally, a thermosensitive recording material is prepared by separately dispersing a developer such as a leuco dye and a phenolic substance into fine particles, and then mixing the two with a binder, a sensitizer, a filler, and the like. Additives such as lubricants to make a coating liquid, applied to paper, film, synthetic paper, etc., and the color is formed by the chemical reaction that occurs when one or both of the leuco dye and the developer are melted and contacted by heating Get the record. A thermal printer or the like having a built-in thermal head is used for coloring the heat-sensitive recording sheet. This thermal recording method has the following advantages: (1) no noise during recording;
(2) No need for development, fixing, etc., (3) Maintenance-free, (4) Machines are relatively inexpensive, etc., so that they are in the facsimile field, computer output, printer fields such as calculators, medical care It is widely used in the field of recorders for measurement, the field of automatic ticket vending machines, the field of thermal recording labels, and the like.

[0003] Recently, the use of such features as application to vouchers such as commuter tickets and coupons, cards and the like has been expanding. The demand for the heat-sensitive recording material has also changed from one-time use (recording) to one that can withstand many uses, and the support of the heat-sensitive recording material is also made of paper with good mechanical strength and water resistance. There is a demand for conversion to a synthetic plastic film or synthetic paper.

Conventionally, a thermosensitive coloring composition (ink or paint, etc.) used for forming a thermosensitive coloring recording layer on a paper support is prepared by dispersing a thermosensitive recording material in which water is dispersed in a medium. This product had good adhesiveness to paper, but had poor coating and printability and adhesiveness to plastic films and synthetic papers, and was insufficient. Therefore, the use of a thermosensitive coloring composition using an organic solvent as a medium is considered, and although the coating property or printing property and adhesiveness are improved, the organic solvent used, a polymer compound as a binder, There are restrictions on the combination of heat-sensitive recording materials and the like, and there are dissatisfactions with the heat-sensitive recording characteristics, especially background fog and color sensitivity, as well as plasticizer resistance and oil resistance.

[0005]

The object of the present invention is as described above.
It is to solve the disadvantages of the prior art. That is, an object of the present invention is to provide an organic solvent type thermosensitive coloring composition and a recording material for forming a thermosensitive coloring recording layer having less background fogging, excellent coloring density and good storage stability.

[0006]

Means for Solving the Problems The present inventors have made various studies to achieve the above object, and as a result, completed the present invention. That is, the present invention relates to (1) a thermosensitive color-forming composition obtained by dispersing a color-developing compound, a color-forming compound which reacts with the color-developing compound under heating, and a polymer compound in an organic solvent. In this case, 2- (o-
(Fluoroanilino) -6-diethylaminofluoran or 2- (o-chloroanilino) -6-diethylaminofluoran as the color-developing compound represented by the following formula (1)

[0007]

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(2) a thermosensitive coloring composition, wherein the organic solvent is a hydrocarbon-based organic solvent; and (3) a hydrocarbon-based coloring composition. (2) The thermosensitive coloring composition in which the organic solvent is liquid at room temperature, and (4) the hydrocarbon-based organic solvent which is liquid at room temperature is an aromatic hydrocarbon, a naphthenic hydrocarbon, or a paraffinic hydrocarbon ( The present invention also relates to (3) a thermosensitive coloring composition, and (5) a thermosensitive recording material obtained by applying the thermosensitive coloring composition according to any one of (1) to (4) on a support and drying.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-sensitive color-forming composition of the present invention contains the above-described color-forming compound, ie, 2- (o-fluoroanilino) -6-diethylaminofluoran or 2- (o-) in an organic solvent. Chloroanilino) -6-diethylaminofluoran and a color-developing compound, that is, a compound of the formula (1), a polymer compound, and other necessary additives are mixed and dispersed. The use ratio of the above-described coloring compound and the developing compound is 1 part by weight of 2- (o-fluoroanilino) -6-diethylaminofluoran or 2- (o-chloroanilino) -6-diethylaminofluoran. On the other hand, the compound represented by the formula (1) is 1 to 10
A suitable amount is 1 part by weight, preferably 1 to 5 parts by weight. These chromogenic compounds and the compound of the formula (1), as a total amount of both, are 30 to 90% by weight, preferably 60 to 80% by weight in the total solids (components excluding the organic solvent) of the thermosensitive coloring composition. %.

Examples of the organic solvent include hydrocarbon solvents, preferably those which are liquid at room temperature, and specific examples thereof include aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons. These solvents may be used alone or as a mixture. Examples of the aromatic hydrocarbon which is liquid at normal temperature include benzene, toluene, xylene, ethylbenzene, ethyltoluene and the like, and a mixture thereof. Among them, it is preferable to use toluene and / or xylene. Examples of naphthenic hydrocarbons that are liquid at room temperature include cyclopentane, methylcyclopentane, 1,1-dimethylcyclopentane, 1,3-dimethylcyclopentane, cyclohexane, ethylcyclohexane, 1,2,4-trimethylcyclohexane and the like. Or a mixture thereof. Among them, it is preferable to use cyclohexane and / or ethylcyclohexane. Examples of paraffinic hydrocarbons that are liquid at room temperature include n-hexane, n-heptane, n-octane, n-nonane, or isomers thereof.
Or a mixture thereof. This amount is about 50 to 1000 v / w%, preferably about 100 to 500 v / w%, based on the total amount of solids.

The polymer compound is used as a binder, and a compound which is soluble in an organic solvent to be used and has a film-forming property is used. Specific examples thereof include polyvinyl chloride, acrylic resin, acrylic styrene copolymer, polyester resin, polycarbonate resin, polyurethane resin, polybutyral resin, epoxy resin, furan resin, vinyl toluene copolymer, rosin ester resin and the like. Can be These polymer compounds are present in the total solids of the composition in an amount of from 1 to 7
0% by weight, preferably 10 to 40% by weight.

In the composition of the present invention, other than the above-mentioned components, other color-forming compounds, color-developing compounds and additives may be used in combination, if necessary. Specific examples thereof are as follows. The amount of each used is 0
It is about 30% by weight.

Examples of the color-forming compounds that can be used in combination include fluoran compounds, triarylmethane compounds, spiropyran compounds, diphenylmethane compounds, thiazine compounds, lactam compounds, and fluorene compounds. Examples of the fluoran-based compound include 2-aniline-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6- (N-methyl-N-cyclohexylamino) fluoran, and 2-anilino-3-methyl -6- (N-ethyl-N-isopentylamino) fluoran, 2- (p-chloroanilino) -3
-Methyl-6-diethylaminofluoran, 2- (p-
Fluoroanilino) -3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6- (N-
(P-tolyl) -N-ethylamino) fluoran, 2-
(P-toluidino) -3-methyl-6-diethylaminofluoran, 2- (o-chloroanilino) -6-dibutylaminofluoran, 2- (o-fluoroanilino)-
6-dibutylaminofluoran, 2-anilino-3-methyl-6-piperidinofluoran, 2-anilino-3-
Methyl-6-pyrrolidinofluoran, 2-ethoxyethylamino-3-chloro-6-diethylaminofluoran, 2-anilino-3-chloro-6-diethylfluoran, 2-chloro-6-diethylaminofluoran, 2 −
Methyl-6-diethylaminofluoran and the like.

As the triarylmethane compound, for example, 3,3-bis (p-dimethylaminophenyl) -6
-Dimethylaminophthalide (alias: crystal violet lactone), 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylaminoindole-3
-) Isophthalide and the like, as spiropyran-based compounds, for example, 3-methyl-3-spirodinaphthopyran,
1,3,3-trimethyl-6-nitro-8'-methoxyspiro (indoline-2,2'-benzopyran) and the like; diphenylmethane-based compounds such as N-halophenyl-leucouramine and the like; For example, benzoylleucomethylene blue and the like, and as the lactam compound, for example, rhodamine-
Examples of fluorene-based compounds such as B-anilinolactam include, for example, 3,6-bus (dimethylamino) fluorenespiro (9,3 ′)-6′-dimethylaminophthalide and 3,6-bis (dimethylamino) Fluorene spiro (9,3 ')-6'-pyrrolidinophthalide, 3-dimethylamino-6-diethylaminofluorene spiro (9,3'
3 ′)-6′-pyrrolidinophthalide and the like.

Examples of the color developing compound which can be used in combination are, for example, α-naphthol, β-naphthol, p-octylphenol, 4-t-octylphenol, pt-butylphenol, p-phenylphenol, 1,1-bisphenol (P-hydroxyphenyl) propane, 2,2-bis (p-hydroxyphenyl) propane, (also known as bisphenol A or BPA) 2,2-bis (p-hydroxyphenyl) butane, 1,1-bis (p- (Hydroxyphenyl) cyclohexane, 4,4′-thiobisphenol, 4,4′-cyclo-hexylidenediphenol,
4,4'-dihydroxydiphenyl sulfone, bis-
(3-allyl-4-hydroxyphenyl) sulfone,
2,2'-bis (2,5-dibromo-4-hydroxyphenyl) propane, 4,4'-isopropylidenebis (2-t-butylphenol), 2,2'-methylenebis (4-chlorophenol), -Hydroxy-4'-
Phenolic compounds such as isopropoxydiphenyl sulfone, methyl bis (4-hydroxyphenyl) acetate, butyl bis (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate, benzyl p-hydroxybenzoate, p-hydroxy Ethyl benzoate, 4-
Dibenzyl hydroxyphthalate, dimethyl 4-hydroxydiphthalate, ethyl 5-hydroxyisophthalate, 3,
Examples thereof include aromatic carboxylic acid derivatives such as 5-di-t-butylsalicylic acid and 3,5-di-α-methylbenzylsalicylic acid, aromatic carboxylic acids and polyvalent metal salts thereof.

Other additives used as needed include, for example, fillers and heat-fusible compounds (sensitizers). Examples of these additives are given below.

Examples of usable fillers include calcium carbonate, magnesium carbonate, magnesium oxide, silica, white carbon, talc, clay, alumina, magnesium hydroxide, aluminum hydroxide, aluminum oxide, barium sulfate, polystyrene resin, Urea-formalin resin and the like.

Examples of usable heat-fusible compounds include waxes such as animal and vegetable waxes and synthetic waxes, higher fatty acids, higher fatty acid amides, higher fatty acid anilides, acetylated aromatic amines, naphthalene derivatives, aromatic ethers, and the like. Aromatic carboxylic acid derivatives, aromatic sulfonic acid ester derivatives, carbonic acid or oxalic acid diester derivatives, biphenyl derivatives, terphenyl derivatives, etc., which are solid at room temperature and have a melting point of about 70 ° C. or more can be used.

Examples of waxes that can be used include, for example, wood wax, carnauba wax, shellac, paraffin,
Montan wax, paraffin oxide, polyethylene wax, polyethylene oxide, etc., as higher fatty acids, for example, stearic acid, behenic acid, etc., as higher fatty acid amides, for example, stearic acid amide, oleic acid amide,
N-methylstearic acid amide, erucic acid amide, methylolbehenic acid amide, methylolstearic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide and the like, as higher fatty acid anilide,
For example, stearic acid anilide, linoleic acid anilide and the like, acetylated aromatic amines such as acetotoluidide, and naphthalene derivatives such as 1-benzyloxynaphthalene, 2-benzyloxynaphthalene and 1-hydroxynaphthoic acid phenyl ester And the like, as aromatic ethers, for example, 1,2-diphenoxyethane, 1,4-diphenoxybutane, 1,2-
Bis (3-methylphenoxy) 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 and the like, and examples of the aromatic carboxylic acid derivative include p-hydroxybenzoic acid benzyl ester, p-benzyloxybenzoic acid benzyl ester, terephthalic acid dibenzyl ester and the like. Examples of the aromatic sulfonic acid ester derivatives include p-toluenesulfonic acid phenyl ester, phenylmesitylenesulfonate, and 4-methylphenylmesitylenesulfonate, and examples of the carbonic acid or oxalic acid diester derivatives include diphenyl carbonate and dioxalic acid. Benzyl ester, oxalic acid di ( - methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester and the like,
Examples of the biphenyl derivative include, for example, p-benzylbiphenyl and p-allyloxybiphenyl, and examples of the terphenyl derivative include, for example, m-terphenyl.

Other additives such as lubricants such as zinc stearate, calcium stearate, and aluminum stearate, various surfactants, defoamers, and ultraviolet absorbers are added as required.

The heat-sensitive color-forming composition of the present invention is prepared using the above-mentioned materials by, for example, the following method. That is,
First, the above-mentioned compound of 2- (o-fluoroanilino) -6-diethylaminofluoran or 2- (o-chloroanilino) -6-dimethylaminofluoran, the compound of the formula (1) is prepared by an ordinary method in an organic solvent. After separately pulverized and dispersed in a dispersing machine such as a ball mill, an attritor, or a sand mill together with a binder or other additives as necessary, and then mixed at a ratio within the range described in the present invention, the heat-sensitive material of the present invention A color forming composition is obtained.

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 applying the above-described heat-sensitive color-forming composition of the present invention on a support such as paper, plastic film, synthetic paper, or fiber sheet by a conventional method. In this case, the coating can be performed by a normal coating method using a bar coater, a roll coater, a reverse coater, a doctor coater, a microgravure coater, or the like, and printing by a method such as gravure, letterpress, flexo, or silk screen is also possible. . After the application, the organic solvent is dried and removed by a conventional method such as air drying (normal temperature) or hot air drying up to about 150 ° C. to obtain the heat-sensitive recording material of the present invention. The heat-sensitive recording layer is usually formed on the support as a coating film having a dry weight of 0.5 to 20 g / m ² . In the heat-sensitive recording material of the present invention, an overcoat layer of, for example, polyvinyl alcohol can be provided on the heat-sensitive recording layer, if necessary.

In an organic solvent, 2- as a color-forming compound
A book comprising (o-fluoroanilino) -6-diethylaminofluoran or 2- (o-chloroanilino) -6-diethylaminofluoran as a color developing compound containing a compound of the formula (1) and a polymer compound. The heat-sensitive coloring composition of the present invention has good coatability or printability and adhesion to paper, plastic film, synthetic paper, etc., and the heat-sensitive recording material of the present invention prepared by using the same has good coloring properties. And excellent storage stability.

[0024]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. still,
In the examples, "parts" indicates parts by weight.

Example 1 A mixture having the following composition was pulverized for 30 minutes using a sand grinder to prepare a liquid [A] and a liquid [B]. [A] solution: 2- (o-fluoroanilino) -6-diethylaminofluoran 40 parts toluene 60 parts [B] solution: compound of formula (1) (CAS No. 92192-08-0) 40 parts toluene 60 Department

Next, the mixture is mixed at the following ratio to obtain the thermosensitive coloring composition of the present invention. [A] solution 12.5 parts [B] solution 37.5 parts 20% methyl methacrylate-styrene copolymer (molecular weight = about 100,000) toluene solution 40.0 parts Next, this thermosensitive coloring composition was A thermosensitive coloring layer is provided on a 188 μm-thick white polyester film so as to have a dry weight of 6 g / m ² and dried. Further, the applied amount of a 10% PVA aqueous solution on the thermosensitive coloring layer when dried is 2 g.
/ M ² to obtain the heat-sensitive recording material of the present invention.

Example 2 2- (o-fluoroanilino)-of the solution [A] of Example 1
The heat-sensitive recording material of the present invention is obtained in the same manner as in Example 1 except that 2- (o-chloroanilino) -6-diethylaminofluorane is used instead of 6-diethylaminofluoran.

Example 3 A mixture having the following composition was pulverized for 30 minutes using a sand grinder to prepare Solution [C] and Solution [D]. [C] solution: 2- (o-fluoroanilino) -6-diethylaminofluoran 25 parts tetralin 75 parts [D] solution: compound of formula (1) (CAS No. 92192-08-0) 25 parts tetralin 75 Department

Then, the mixture is mixed at the following ratio to obtain the thermosensitive coloring composition of the present invention. [C] solution 16 parts [D] solution 48 parts 20% methyl methacrylate / styrene / ethyl acrylate copolymer (molecular weight = about 100,000) toluene solution 40 parts Next, this thermosensitive color-forming composition was coated with a thickness. A thermosensitive coloring layer is provided on a 188 μm white polyester film so as to have a dry weight of 6 g / m ² and dried. Further, the applied amount of a 10% PVA aqueous solution on the thermosensitive coloring layer when dried is 2 g.
/ M ² to obtain the heat-sensitive recording material of the present invention.

Comparative Example 1 In place of the compound of the formula (1) of Example 1, JP-A No. 1-9
A comparative thermosensitive coloring composition is prepared in the same manner as in Example 1 except that bisphenol A used in the example of No. 6271 is used, and then a thermosensitive coloring sheet for comparison is obtained therefrom.

Comparative Example 2 The procedure of Example 1 was repeated, except that the crystal violet lactone used in Examples of JP-A-1-96272 was used instead of 2- (o-fluoronoanilino) -6-diethylaminofluoran. A comparative thermosensitive coloring composition was prepared in the same manner as in Example 1, and then a comparative thermosensitive coloring sheet was obtained therefrom. Table 1 shows the quality performance test results of the heat-sensitive recording material of the present invention and the heat-sensitive coloring sheet for comparison obtained as described above.

[0032]

Table 1 Quality performance test Ground 1) Color density 2) Plasticizer resistance 3) Oil resistance 4) Example 1 0.06 1.43 1.42 1.43 Example 2 0.06 1. 42 1.41 1.41 Example 3 0.06 1.48 1.47 1.47 Comparative Example 1 0.32 1.40 0.39 0.40 Comparative Example 2 0.77 1.42 1.11 1 .19

1) Background: A value (reflection density) of an uncolored portion of the produced thermosensitive coloring sheet measured with a Macbeth reflection densitometer RD-914. 2) Color density: Macbeth reflection density of a portion printed by a commercially available thermal printer (D-805P, manufactured by Ishida Koki). 3) Plasticizer resistance: Macbeth reflection density after leaving the plastic eraser at a temperature of room temperature for 48 hours with a pressure of 100 to 200 g / cm ² applied to the portion printed by the printer. 4) Oil resistance: Macbeth reflection density after applying cottonseed oil to a portion printed by the above printer and wiping it after 10 seconds and leaving it to stand for 24 hours.

As is clear from the above-mentioned quality performance test table, the heat-sensitive recording material prepared by using the heat-sensitive color-forming composition of the present invention has little background fogging, and is excellent in color density, plasticizer resistance, oil resistance and the like. I have.

[0035]

According to the present invention, a heat-sensitive color recording material (sheet) having less background fog and excellent color density and storage stability can be easily obtained.

Claims (5)

[Claims] 1. A thermosensitive color-forming composition comprising a color developing compound, a color forming compound which reacts with the color developing compound under heating to form a color, and a polymer compound in an organic solvent. 2- (o-fluoroanilino) -6- as a coloring compound
Diethylaminofluoran or 2- (o-chloroanilino) -6-diethylaminofluoran is represented by the following formula (1): A heat-sensitive color-forming composition comprising the compound of formula (I). 2. The thermosensitive coloring composition according to claim 1, wherein the organic solvent is a hydrocarbon-based organic solvent. 3. The thermosensitive coloring composition according to claim 2, wherein the hydrocarbon organic solvent is liquid at room temperature. 4. The thermosensitive coloring composition according to claim 3, wherein the hydrocarbon organic solvent which is liquid at normal temperature is an aromatic hydrocarbon, a naphthenic hydrocarbon or a paraffin hydrocarbon. 5. A thermosensitive recording material obtained by applying the thermosensitive coloring composition according to any one of claims 1 to 4 on a support and drying.