JP2000289345A - Heat-sensitive coloring composition and heat-sensitive recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-sensitive coloring composition for the development and manufacture of a heat-sensitive recording material of superior coloring properties and storage stability. SOLUTION: A heat-sensitive coloring composition is composed of a development compound, a coloring compound reacted with the development compound under heating and colored and a polymer compound, all of which are dispersed in an organic solvent. In that case, a heat-sensitive coloring composition containing a 3-diethylamino-7(m-trifuluoromethyl anilino)fluoran as the coloring compound and a heat-sensitive recording material manufactured by applying the heat-sensitive coloring 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 and a thermosensitive recording material of an organic solvent dispersion type having excellent coloring properties and preservability.

[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 with a binder, a sensitizer, and a filler. Agents, lubricants and other additives to make a coating liquid, paper,
It is applied to a film, synthetic paper, or the like, and obtains a color record by a chemical reaction that occurs when one or both of the leuco dye and the color developer melt and come into contact by heating. For color development of such a heat-sensitive recording sheet, a thermal printer or the like having a built-in thermal head is used. Compared with other recording methods, this thermal recording method is (1) no noise during recording, (2) there is no need for development and fixing, (3) maintenance-free, (4) machine is relatively inexpensive. It is widely used in the field of facsimile machines, computer output, printers such as calculators, recorders for medical measurements, automatic ticket vending machines, 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, and the support for heat-sensitive recording materials has better surface uniformity than paper or the like. Use of plastic films and synthetic papers having good mechanical 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, 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 thermosensitive recording material for forming a thermosensitive coloring recording layer having less background fog, 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 heat-sensitive 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. 3-diethylamino-7- (m-trifluoromethylanilino) as the color-forming compound
A heat-sensitive color-forming composition characterized by containing fluoran; (2) a heat-sensitive color-forming composition according to (1), wherein the organic solvent is a hydrocarbon-based organic solvent; and (3) a hydrocarbon-based organic solvent at room temperature. (2) a thermosensitive coloring composition which is liquid
(4) The thermosensitive coloring composition according to (3), wherein the hydrocarbon-based organic solvent which is liquid at normal temperature is an aromatic hydrocarbon, a naphthenic hydrocarbon, or a paraffin-based hydrocarbon; (5) (1) to (4) The present invention also relates to a thermosensitive recording material obtained by applying a layer of the thermosensitive color-forming composition according to any one of the above to a support and drying it.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-sensitive color-forming composition of the present invention comprises the above-described color-forming compound, ie, 3-diethylamino-7- (m-trifluoromethylanilino) fluoran, and a color developing compound in an organic solvent. And a polymer compound, as well as other necessary additives and the like, and then mixed and dispersed.
The use ratio of the above-mentioned 3-diethylamino-7- (m-trifluoromethylanilino) fluoran and the color-developing compound is as follows with respect to 1 part by weight of 3-diethylamino-7- (m-trifluoromethylanilino) fluoran. The color developing compound is suitably used in an amount of 1 to 10 parts by weight, preferably 1 to 5 parts by weight. The total amount of 3-diethylamino-7- (m-trifluoromethylanilino) fluoran and the color-developing compound is 10 to 90% by weight in the total solid content (component excluding the organic solvent) of the thermosensitive coloring composition. %, Preferably 30 to
80% by weight, 1 to 70% by weight of the polymer compound, preferably 10 to 40% by weight, and other additives and the like may be contained in optional proportions, for example, 0 to 30% by weight.
In addition, 3-diethylamino-7- (m-trifluoromethylanilino) fluoran is CAS No. 6813
4-6-1-2 is a known compound registered in Chemical Abstract.

[0008] Examples of the organic solvent used in the present invention include hydrocarbon solvents such as aromatic hydrocarbons, naphthenic hydrocarbons, and paraffinic hydrocarbons, and 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 may be mentioned. These solvents may be used alone or as a mixture. The amount used is 50 to 1000% by weight, preferably 100 to 500% by weight, based on the total amount of solids.
% By weight.

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 usable color developing compounds include, for example, α-naphthol, β-naphthol, p-octylphenol, 4-t-octylphenol, pt-butylphenol, p-phenylphenol, 1,1′-bis ( p-hydroxyphenyl) propane, 2,2′-bis (p-hydroxyphenyl) propane, 2,2′-bis (p-hydroxyphenyl) butane, 1,1′-bis (p-hydroxyphenyl) cyclohexane, , 4 '
-Thiobisphenol, 4,4'-cyclo-hexylidenediphenol, 4,4'-dihydroxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone,
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), 4-hydroxy-4 '
-Isopropoxydiphenyl sulfone, methyl bis (4-hydroxyphenyl) acetate, butyl bis (4-hydroxyphenyl) acetate, bis (4-hydroxyphenyl)
Phenolic compounds such as benzyl acetate; benzyl p-hydroxybenzoate; ethyl p-hydroxybenzoate;
-Dibenzyl hydroxyphthalate, dimethyl 4-hydroxydiphthalate, ethyl 5-hydroxyisophthalate,
3,5-di-t-butylsalicylic acid, 3,5-di-α-
Examples include aromatic carboxylic acid derivatives such as methylbenzyl salicylic acid, and aromatic carboxylic acids.

Other additives used as required 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, 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 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, and ethylenebisstearin Acid amides and the like, higher fatty acid anilides such as stearic acid anilide and linoleic acid anilide, acetylated aromatic amines such as acetotoluidide, and naphthalene derivatives such as 1-benzyloxynaphthalene, Benzyloxynaphthalene, 1-hydroxynaphthoic acid phenyl ester and the like include aromatic ethers such as 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 include aromatic carboxylic acid derivatives such as benzyl p-hydroxybenzoate,
Examples of aromatic sulfonic acid ester derivatives include benzyl p-benzyloxybenzoate and dibenzyl terephthalate, for example, phenyl p-toluenesulfonate, phenylmesitylenesulfonate,
-Methylphenyl mesitylenesulfonate and the like are carbonic acid or oxalic acid diester derivatives, for example, diphenyl carbonate, dibenzyl oxalate, dioxalic acid (4
-Methylbenzyl) ester, oxalic acid di (4-chlorobenzyl) ester and the like, as biphenyl derivatives,
For example, p-benzylbiphenyl, p-allyloxybiphenyl and the like are terphenyl derivatives such as m-
Terphenyl and the like are each exemplified.

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

The thermosensitive coloring composition of the present invention is prepared by using the above-mentioned materials by, for example, the following method. That is,
First, 3-diethylamine-7- (m-trifluoromethylanilino) fluorane and a color-developing compound are separately separated in an organic solvent by a ball mill together with a binder or other additives as necessary. After being pulverized and dispersed by a disperser such as an attritor or a sand mill, they are mixed in the proportions described in the present invention 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, for example, 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.

The thermosensitive coloring composition of the present invention comprising an organic solvent containing 3-diethylamino-7- (m-trifluoromethylanilino) fluoran as a coloring compound, a developing compound and a polymer compound. The product 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 using the same has excellent color-forming properties and preservability. There are features.

[0019]

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 obtain a solution [A] and a solution [B], respectively. [A] solution: 3-diethylamino-7- (m-trifluoromethylanilino) fluorane 40 parts toluene 60 parts [B] solution: bis (3-allyl-4-hydroxyphenyl) sulfone 40 parts toluene 60 parts

Then, the mixture was mixed in the following ratio to obtain a 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 It was applied on a white polyester film having a thickness of 188 μm so as to have a dry weight of 6 g / m ^2, and dried to form a thermosensitive coloring layer. Further, the applied amount of the 10% PVA aqueous solution on the thermosensitive coloring layer when dried is 3 g.
/ M ² to obtain a heat-sensitive recording material of the present invention.

Example 2 The same procedure as in Example 1 was repeated except that the 25% 2,4'-dihydroxydiphenylsulfone dispersion, which had been pulverized and dispersed in place of the solution [B] in Example 1, was used. A heat-sensitive recording material was obtained.

Example 3 A mixture having the following composition was pulverized for 30 minutes using a sand grinder to obtain a solution [C] and a solution [D], respectively. [C] solution: 3-diethylamino-7- (m-trifluoromethylanilino) fluoran 25 parts tetralin 75 parts [D] solution: bis (3-allyl-4-hydroxyphenyl) sulfone 25 parts tetralin 75 parts

Then, the mixture was mixed at the following ratio to obtain a 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 was 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 the 10% PVA aqueous solution on the thermosensitive coloring layer when dried is 3 g.
/ M ² to obtain a heat-sensitive recording material of the present invention.

Comparative Example 1 Comparative thermosensitive coloring was performed in the same manner as in Example 1 except that crystal violet lactone was used in place of 3-diethylamino-7- (m-trifluoromethylanilino) fluoran. A heat-sensitive coloring sheet for comparison was prepared from the composition. Using the heat-sensitive recording material of the present invention obtained as described above and a heat-sensitive coloring sheet for comparison, the following quality tests were carried out.

Table 1 Quality performance test Ground 1) Color density 2) Plasticizer resistance 3) Oil resistance 4) Example 1 0.06 1.55 1.53 1.54 Example 2 0.05 1.51 1.49 1.50 Example 3 0.06 1.55 1.54 1.53 Comparative Example 1 0.75 1.46 1.11 1.17

1) Background: The undeveloped portion of the produced thermosensitive recording material or thermosensitive coloring sheet is measured by Macbeth reflection densitometer R
The value (reflection density) measured by D-914 type. 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 stable images such as color density, plasticizer resistance and oil resistance. Excellent (preservation) property.

[0029]

According to the present invention, a thermosensitive color recording material (sheet) having little 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. A thermosensitive coloring composition comprising 3-diethylamino-7- (m-trifluoromethylanilino) fluoran as a compound. 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.