JP2000289343A - Heat-sensitive coloring composition and heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-sensitive coloring composition for manufacturing a heat-sensitive recording material of superior coloring properties and storage properties. SOLUTION: A heat-sensitive coloring composition is composed of a development compound, a coloring compound reacted with the development compound by heating and colored and a polymer compound, both of which are dispersed in an organic solvent. In that case, a heat-sensitive coloring composition containing a compound represented by a formula and a heat-sensitive recording material manufactured by applying the heat-sensitive composition on a substrate and dried thereon can be obtained.

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 a thermosensitive coloring composition of an organic solvent dispersion type having excellent coloring properties and preservability, and a thermosensitive recording material obtained by coating and drying the composition.

[0002]

2. Description of the Related Art In general, 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, and then adding a binder, a sensitizer, a filler, Additives such as lubricants and make a coating solution, paper, film, coated on synthetic paper, etc., one or both of the leuco dye and the developer are melted by heating, due to the chemical reaction that occurs upon contact, A color recording record is obtained. 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 field such as calculators, medical field. It is widely used in the field of recorders for measurement, the field of automatic ticket vending machines, the field of heat-sensitive 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 heat-sensitive recording materials has also changed from one-time use (recording) to one that can withstand many uses. The use of plastic films and synthetic papers having good strength and water resistance has been increasing.

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, which causes dissatisfaction with the important heat-sensitive recording characteristics, particularly background fogging and coloring 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 the present invention, the color-developing compound has 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 comprises a color-forming compound and a color-developing compound, that is, a compound of the formula (1) and a polymer compound in an organic solvent. It is obtained by mixing and dispersing with additives and the like. The ratio of the color-forming compound to the color-developing compound is 1 to 10 parts by weight, preferably 1 to 5 parts by weight, for 1 part by weight of the color-forming compound. It is. These chromogenic compounds and the compound of the formula (1) are used in a total amount of 10 to 90% by weight, preferably 3 to 90% by weight in the total solid content (component excluding the organic solvent) of the thermosensitive chromogenic composition.
0 to 80% by weight, the polymer compound is 1 to 70% by weight, preferably 10 to 40% by weight, and if necessary, additives and the like are contained in any ratio, for example, 0 to 30% by weight.
In addition, the compound represented by the formula (1) was obtained from CAS No. 1
26-00-1 is a known compound registered in Chemical Abstracts.

The organic solvent used in the present invention includes, for example, hydrocarbon solvents such as aromatic hydrocarbons, naphthenic hydrocarbons and paraffinic hydrocarbons, preferably hydrocarbon solvents which are liquid at room temperature. 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, methylcyclohexane, ethylcyclohexane, 1,2,4-trimethylcyclohexane and the like, and mixtures thereof, among which cyclohexane and / or ethyl Preferably, cyclohexane is used. Examples of paraffinic hydrocarbons that are liquid at room temperature include n-hexane, n-heptane, and n-hexane.
Octane, n-nonane, or an isomer thereof, or a mixture thereof is included. The amount used is 50 to 1000% by weight, preferably 100% by weight, based on the total solid content.
About 500% by weight. These solvents may be used alone or as a mixture.

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, polystyrene resin, acrylic resin, acrylic styrene copolymer, polyester resin, polycarbonate resin, polyurethane resin, polybutyral resin, epoxy resin, furan resin, vinyl toluene copolymer, and rosin ester resin. And the like. These polymer compounds are contained in an amount of 1 to 70% by weight, preferably 10 to 40% by weight, in the total solid content in the composition.

Examples of the color-forming compound used in the heat-sensitive coloring layer are not particularly limited as long as they are those generally used in pressure-sensitive recording paper or heat-sensitive recording paper. Specific examples include, for example, fluoran compounds, triarylmethane compounds, spiro compounds, diphenylmethane compounds,
Thiazine-based compounds, lactam-based compounds, fluorene-based compounds and the like can be mentioned.

Among these, fluoran compounds include, for example, 3-diethylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3- (N-methyl- N-cyclohexylamino) -6-methyl-7-anilinofluoran, 3
-(N-ethyl-N-isopentylamino) -6-methyl-7-anilinofluoran, 3-isobutylethylamino-6-methyl-7-anilinofluoran, 3- (N
-Ethyl-N-ethoxypropylamino) -6-methyl-7-anilinofluoran, 3- (N-methyl-N-hexylamino) -6-methyl-7-anilinofluoran, 3-dipentylamino- 6-methyl-7-anilinofluoran, 3- (N-methyl-N-propylamino)
-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-tetrahydrofurylamino) -6-methyl-
7-anilinofluoran, 3-diethylamino-6-methyl-7- (p-chloroanilino) fluoran, 3-diethylamino-6-methyl-7- (p-fluoroanilino) fluoran, 3- (p-toluidine Noethylamino-
6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (p-toluidino) fluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-diethylamino-6-chloro -7-ethoxyethylaminofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-
7- (o-chloroanilino) fluoran, 3-dibutylamino-7- (o-chloroanilino) fluoran, 3-
Diethylamino-7- (o-fluoroanilino) fluoran, 3-dibutylamino-7- (o-fluoroanilino) fluoran, 3-diethylamino-7- (3,4-
Dichloroanilino) fluoran, 3-diethylamino-
7-chlorofluorane, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-7-
Methylfluoran, 3-diethylamino-7-octylaminofluoran, 3-diethylamino-7-phenylfluoran, 3- (p-toluidinoethylamino) -6
-Methyl-7-phenethylfluoran and the like.

The triarylmethane compounds include, for example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (also known as crystal violet lactone or CVL), 3,3-bis (p
-Dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylaminoindole-3-) isophthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindole -3-
Yl) phthalide, 3- (p-dimethylaminophenyl)
-3- (2-Phenylindol-3-yl) phthalide, 3,3-bis (1,2-dimethylindol-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
Dimethylaminophthalide, 3-p-dimethylaminophenyl-3- (1-methylpyrrol-2-yl) -6-dimethylaminophthalide and the like.

Further, as the spiro compound, for example, 3
-Methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3,3'-dichlorospirodinaphthopyran, 3-benzylcipirodinaphthopyran, 3-propylspirobenzopyran, 3-methylnaphtho- (3-methoxybenzopyran ) Spiropyran, 1,3,3-trimethyl-6
-Nitro-8'-methoxyspiro (indoline-2,
2′-benzopyran) and the like as diphenylmethane-based compounds, for example, N-halophenyl-leukoauramine, 4,4-bis-dimethylaminophenylbenzhydryl benzyl ether, N-2,4,5-trichlorophenylleucoura As a thiazine-based compound, for example, benzoyl leucomethylene blue and p-nitrobenzoyl leucomethylene blue, and as a lactam-based compound, for example, rhodamine B anilinolactam,
Rhodamine B-p-chloroanilinolactam and the like are fluorene-based compounds, for example, 3,6-bus (dimethylamino) fluorenespiro (9,3 ′)-6′-dimethylaminophthalide, 3,6-bis (Dimethylamino)
Fluorene spiro (9,3 ')-6'-pyrrolidinophthalide, 3-dimethylamino-6-diethylaminofluorene spiro (9,3')-6'-pyrrolidinophthalide, and the like, respectively. These coloring compounds are used alone or in combination.

Other additives used as needed include, for example, fillers, heat-fusible compounds (sensitizers) and the like. 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, An acrylic resin, a polyolefin resin, a benzoguanamine resin, a melamine resin, a urea-formalin resin, and the like are included.

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, and the like.
Acetylized aromatic amines, naphthalene derivatives, aromatic ethers, aromatic carboxylic acid derivatives, aromatic sulfonic acid ester derivatives, carbonic acid or oxalic acid diester derivatives, biphenyl derivatives, terphenyl derivatives, etc. Those having the above melting points can be used.

Examples of waxes include wood wax, carnauba wax, shellac, paraffin, montan wax,
Paraffin oxide, polyethylene wax, polyethylene oxide and the like, as higher fatty acids, for example, stearic acid,
Examples of higher fatty acid amides such as behenic acid include stearic acid amide, oleic acid amide, N-methylstearic acid amide, erucic acid amide, methylolbehenic acid amide, methylolstearic acid amide, methylenebisstearic acid amide, ethylenebisstearin Examples of acid amides include higher fatty acid anilides such as stearic acid anilide and linoleic acid anilide, and examples of acetylated aromatic amines include acetotoluizide.

The naphthalene derivatives include, for example, 1
-Benzyloxynaphthalene, 2-benzyloxynaphthalene, 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
Examples of aromatic carboxylic acid derivatives include-(4-methoxyphenoxy) ethane and the like. Examples of aromatic carboxylic acid derivatives include p-hydroxybenzoic acid benzyl ester, p-benzyloxybenzoic acid benzyl ester, terephthalic acid dibenzyl ester and the like. Derivatives include, for example, p-toluenesulfonic acid phenyl ester, phenylmesitylenesulfonate, 4-methylphenylmesitylenesulfonate, and the like. Carbonic acid or oxalic acid diester derivatives include, for example, diphenyl carbonate, dibenzyl oxalate, dioxalate. (4-methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester and the like include biphenyl derivatives such as p-benzylbiphenyl and p-benzylbiphenyl.
-Allyloxybiphenyl and the like, and examples of the terphenyl derivative include m-terphenyl and the like.

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 thermosensitive coloring composition of the present invention is prepared using the above-mentioned materials by, for example, the following method. That is,
First, a color-forming compound and a compound of the formula (1) are separately mixed in an organic solvent with a binder or, if necessary, other additives by a ball mill, an attritor, or the like.
After being pulverized and dispersed by a disperser such as a sand mill, the mixture is mixed in the above-mentioned ratio to obtain the thermosensitive coloring 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 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 normal drying 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 made of, for example, polyvinyl alcohol (PVA) can be provided on the heat-sensitive recording layer, if necessary.

The heat-sensitive color-forming composition of the present invention comprising a compound of the formula (1) as a color-forming compound and a color-developing compound and a polymer compound in an organic solvent can be used as a paper, plastic film, synthetic paper, etc. The heat-sensitive recording material of the present invention prepared using such a material has good colorability and preservability.

[0025]

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 crushed for 30 minutes using a sand grinder to prepare a solution [A] and a solution [B], respectively. [A] solution: 3-diethylamino-7- (o-fluoroanilino) fluoran 40 parts toluene 60 parts [B] solution: compound of formula (1) (CAS No. 126-00-1) 40 parts toluene 60 parts

Then, the mixture is mixed in 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 The 3-diethylamino-7- (o-
A heat-sensitive recording material of the present invention is obtained in the same manner as in Example 1 except that 3-diethylamino-7- (o-chloroanilino) fluoran is used instead of (fluoroanilino) fluoran.

Example 3 A mixture having the following composition was pulverized for 30 minutes using a sand grinder to prepare a solution [C] and a solution [D], respectively. [C] solution: 3-diethylamino-7- (o-fluoroanilino) fluoran 25 parts tetralin 75 parts [D] solution: compound of formula (1) 25 parts tetralin 75 parts

Next, 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, when the 10% PVA aqueous solution is dried on the thermosensitive coloring layer in an amount of 2%.
g / m ² and dried to obtain the heat-sensitive recording material of the present invention.

Comparative Example 1 A comparative thermosensitive coloring composition was prepared in the same manner as in Example 1 except that bisphenol A was used in place of the compound of the formula (1) in Example 1. Is obtained.

Table 1 shows the quality performance test results of the heat-sensitive recording material of the present invention obtained as described above and a heat-sensitive coloring sheet for comparison.

Table 1 Quality performance test Ground 1) Color density 2) Plasticizer resistance 3) Oil resistance 4) Example 1 0.06 1.44 1.41 1.42 Example 2 0.07 1.43 1.40 1.40 Example 3 0.06 1.45 1.46 1.45 Comparative Example 1 0.33 1.40 0.38 0.40

1) Background: A value (reflection density) obtained by measuring an uncolored portion of the produced thermosensitive coloring sheet 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 a plastic eraser at a temperature of room temperature for 48 hours while applying a pressure of 10100 to 200 g / cm ² to a 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 less background fog and excellent color density, plasticizer resistance, oil resistance and the like. I have.

[0036]

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 coloring composition comprising a color developing compound, a color forming compound which reacts with the color developing compound under heating and develops a color, and a polymer compound in an organic solvent. As the reactive compound, 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 color-forming composition according to claim 2, wherein the hydrocarbon-based 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 paraffinic 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.