JPH05131747A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a high sensitive recording material having freedom of sticking, superior capability of head matching and high reliability of image with high sensitivity. CONSTITUTION:In a thermal recording material provided with, as a main constituent, a thermal coloring layer containing a leuco dyestuff and a coupler on a transparent or semi-transparent support such as a film, a synthetic paper or the like, the coloring layer contains in addition styrene-divinylbenzen copolymer porous beads.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material having improved matchability with a thermal head and recorded image quality.

[0002]

2. Description of the Related Art Recently, various recording materials have been researched and developed and put to practical use in the information recording field in response to social demands such as diversification and increase of information, resource saving and pollution-free. Among them, the heat-sensitive recording material is (1) a color image is recorded by simply heating it, and a complicated developing step is unnecessary, (2) it can be produced using a relatively simple and compact apparatus, and the obtained recording The material is easy to handle and the maintenance cost is low. (3) In many cases, paper is used as the support. In this case, not only the cost of the support is low, but also the feel of the obtained recorded matter is improved. Because it is similar to plain paper, it is widely used in the fields of computer output, printers such as calculators, recorders for medical measurement, low and high speed facsimile fields, automatic ticket vending machines, and thermal copying fields. I have been.

In the above-mentioned thermal recording material, a color-forming component-containing layer capable of causing a color-forming reaction by heating is provided on a support such as ordinary paper, synthetic paper or synthetic resin film, and a color image is formed by heating with a thermal head or the like. To be recorded. The difficulty in putting such a system into practice is that the thermal head and the surface of the thermosensitive recording medium cause a phenomenon of adhesion or stickiness when heat is applied. Since this so-called "sticking" hinders smooth feeding of the recording medium, not only the line spacing is shortened during recording, but also the recorded image is drooped, and continuous recording becomes impossible, and even the thermal head may be damaged.

In order to improve the above-mentioned problems, general clay, talc, calcium carbonate, titanium oxide or the like is added to the color forming layer, or the amount of the adhesive in the color forming layer is increased, or waxes. , A release agent, starch powder, parf powder, etc. (JP-A 47-2793, JP-A 48-33832, JP-A 49-90142, JP-A 50-30539, JP-A 50-30539, 52-145228
No.) etc. have been proposed. In addition, Japanese Patent Publication No. 48-479
In No. 99, it is proposed to use coarse particles having an average particle size of 6 to 20 μm, but it is effective for the occurrence of sticking, but the sensitivity is low, the surface is rough, and white spots and white spots occur. Satisfactory results have not been obtained, which leads to the deterioration of image quality.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-sensitivity heat-sensitive recording material which is free from sticking and has excellent head matching properties and high image quality.

[0006]

According to the present invention, a thermosensitive recording material comprising a support and a thermosensitive coloring layer containing a leuco dye and a developer as main components is provided in the coloring layer. Provided is a heat-sensitive recording material, which is characterized in that divinylbenzene-based copolymer beads are added.

That is, the present inventors have conducted extensive studies in view of such a situation, and as a result, as a result, a thermosensitive recording material having a thermosensitive coloring layer containing a leuco dye and a color developer as main components on a support. In the above, by adding a styrene-divinylbenzene-based copolymer bead to the color-developing layer, the original characteristics of the color-developing layer are not destroyed, and sticking-free, high-sensitivity and excellent thermal stability of image stability is obtained. It has been found that the material can be obtained.

The styrene-divinylbenzene copolymer beads used in the present invention are porous beads made of a copolymer of a styrene monomer and a divinylbenzene monomer. For example, a copolymer of styrene and p-divinylbenzene has a repeating unit represented by the following chemical formula 1.

[Chemical 1]

The styrene-divinylbenzene copolymer beads used in the present invention are porous and have an average particle size of 1 to 6 μm. The amount added to the color forming layer is 1 to 8 parts by weight with respect to 1 part by weight of the leuco dye constituting the color forming layer.
It is preferably 2 to 5 parts by weight.

As the leuco dye used in the present invention, generally, leuco dyes known in this type of leuco recording material are applied alone or in combination of two or more kinds, for example, triphenylmethane type, fluorane type, Leuco compounds of dyes such as phenothiazine-based, auramine-based, spiropyran-based, and indinophthalide-based dyes are preferably used. Specific examples of such leuco dyes include those shown below. 3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6
-Dimethylaminophthalide (also known as crystal bioleptlactone), 3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-
Diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3- (Np
-Tolyl-N-ethylamino) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2- {N- (3'-trifluoromethylphenyl) Amino} -6-diethylaminofluorane, 2- {3,6-bis (diethylamino) -9- (o
-Chloranilino) xanthyl benzoate lactam}, 3
-Diethylamino-6-methyl-7- (m-trichloromethylanilino) fluorane, 3-diethylamino-7
-(O-chloranilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-N
-Methyl-N-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7- Anilino Fluoran, 3
-(N, N-diethylamino) -5-methyl-7-
(N, N-dibenzylamino) fluorane, benzoyl leuco methylene blue-, 6'-chloro-8'-methoxy-
Benzindolino-pyrrilospirane, 6'-bromo-3 '
-Methoxy-benzoindolino-pyrrilospirane, 3-
(2'-hydroxy-4'-dimethylaminophenyl)-
3- (2'-methoxy-5'-chlorophenyl) phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl) -3- (2'-methoxy-5'-nitrophenyl)
Phthalide, 3- (2'-hydroxy-4'-diethylaminophenyl) -3- (2'-methoxy-5'-methylphenyl) phthalide, 3-diethylamino-6-methyl-7
-(2 ', 4'-dimethylanilino) fluorane, 3-
(2'-methoxy-4'-dimethylaminophenyl) -3
-(2'-hydroxy-4'-chloro-5'-methylphenyl) phthalide, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7-trifluoromethylanilinoflu Oran,
3-diethylamino-5-chloro-7- (N-benzyl-trifluoromethylanilino) fluorane, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluorane, 3-diethylamino-5-chloro-7 −
(Α-phenylethylamino) fluorane, 3- (N-
Ethyl-p-toluidino) -7- (α-phenylethylamino) fluorane, 3-diethylamino-7- (o-
Methoxycarbonylphenylamino) fluorane, 3-
Diethylamino-5-methyl-7- (α-phenylethylamino) fluorane, 3-diethylamino-7-piperidinofluorane, 2-chloro-3- (N-methyltoluidino) -7- (pn-butylanilino ) Fluoran, 3- (N-benzyl-N-cyclohexylamino)
-5,6-benzo-7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7
-Mesitidino-4 ', 5'-benzofluorane, 3-diethylamino-6-methyl-7- (2', 4'-dimethylanilino) fluorane and the like. 3- (p-dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p-dimethylaminophenyl) -3- {1,1- Bis (p-dimethylaminophenyl) ethylene-2-yl} -6-dimethylaminophthalide, 3- (p-dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-
Phenylethylene-2-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (1-p-dimethylaminophenyl-1-p-chlorophenylethylene-2-yl) -6-dimethylaminophthalide, 3 -(4'-Dimethylamino-2'-methoxy) -3- (1 ''-p-dimethylaminophenyl-1 ''-p-chlorophenyl-
1 ″, 3 ″ -butadiene-4 ″ -yl) benzophthalide, 3- (4′-dimethylamino-2′-benzyloxy) -3- (1 ″ -p-dimethylaminophenyl-1 ″
-Phenyl-1 ", 3" -butadiene-4 "-yl) benzophthalide, 3-dimethylamino-6-dimethylamino-fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3 , 3-bis {2- (p-dimethylaminophenyl) -2- (p-methoxyphenyl) ethenyl} -4,5,6,7-tetrachlorophthalide, 3-bis {1,1-bis (4 -Pyrrolidinophenyl) ethylene-2-yl} -5,6-dichloro-4,7-dibromophthalide, bis (p-dimethylaminostyryl) -1-naphthalenesulfonylmethane, 3 (N-methyl-N-propyl) Amino) -6-methyl-7-anilinofluorane,
3-diethylamino-6-methyl-7-anilinofluorane, 3,6-bis (dimethylamino) fluoranthro (9,3 ')-6'-dimethylaminophthalide, 3-
Diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N- (2-ethoxypropyl) amino-6-methyl-7-anilinofluorane, 3-N-
Ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6
-Methyl-7-mesitidino-4 ', 5'-benzofluorane, 3-N-methyl-N-isobutyl-6-methyl-
7-anilinofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane and the like.

In the present invention, a variety of electron-accepting compounds such as a phenolic compound, a thiophenolic compound, a thiourea derivative, an organic acid and a metal salt thereof may be used as a color developer in one kind or 2 if necessary. More than one kind can be applied, and specific examples thereof include the following. 4,4'-isopropylidene bisphenol, 3,4'-isopropylidene bisphenol, 4,4'-isopropylidene bis (o-methylphenol), 4,4'-secondary butylidene bisphenol 4,4'-isopropylidene bisphenol (O-tert-butylphenol) 4,4 '
-Cyclohexylidenediphenol, 4,4'-isopropylidenebis (2-chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,2'-methylenebis (4-ethyl-6) -Tert-butylphenol), 4,4'-butylidene bis
(6-tert-butyl-2-methyl) phenol,
1,1,3-tris (2-methyl-4-hydroxy-5-
Tert-Butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4,4′-thiobis (6-tert-butyl-2-methyl) phenol, 4 4,4'-diphenol sulfone, 4,2'-diphenol sulfone, 4-isopropoxy-4'-hydroxydiphenyl sulfone, 4
-Benzyloxy-4'-hydroxydiphenyl sulfone, 4,4'-diphenol sulfoxide, isopropyl P-hydroxybenzoate, benzyl P-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1 , 7-Bis (4-hydroxyphenylthio) -3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, 1,3-bis (4-hydroxyphenylthio) -Propane, 2,2'-methylenebis (4-ethyl-6-tert-butylphenol),
1,3-bis (4-hydroxyphenylthio) -2-hydroxypropane, N, N'-diphenylthiourea, N,
N'-di (m-chlorophenyl) thiourea, salicylanilide, 5-chloro-salicylanilide, salicyl-o
-Chloroanilide, 2-hydroxy-3-naphthoic acid,
Zinc thiocyanate antipyrine complex, 2-acetyloxy-3-naphthoic acid zinc salt, 2-hydroxy-1-
Metal salts of naphthoic acid, 1-hydroxy-2-naphthoic acid, hydroxynaphthoic acid such as zinc, aluminum and calcium Bis- (4-hydroxyphenyl) acetic acid methyl ester, Bis- (4-hydroxyphenyl) acetic acid benzyl ester, 4 -{Β- (p-methoxyphenoxy) ethoxy} salicylic acid, 1,3-bis (4-hydroxycumyl) benzene, 1,4-bis (4-hydroxycumyl)
Benzene, 2,4′-diphenol sulfone, 3,3′-diallyl-4,4′-diphenol sulfone, α, α-bis (4-hydroxyphenyl) -α-methyltoluenethiocyanate zinc antipyrine complex, Tetrabromobisphenol A, tetrabromobisphenol S, 4,4 '
-Thiobis (2-methylphenol), 3,4-hydroxy-4'-methyl-diphenylsulfone, 4,4'-thiobis (2-chlorophenol) and the like.

In order to obtain the heat-sensitive recording material of the present invention, a leuco dye, a color developer and the above-mentioned auxiliary components may be bound and supported on a support. As the binder in this case, various conventional binders can be appropriately used. Specific examples of such a binder include the followings. Polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, ethyl cellulose, sodium polyacrylate,
Polyvinylpyrrolidone, acrylamide / acrylic acid ester copolymer, acrylamide / acrylic acid ester / methacrylic acid terpolymer, styrene / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide In addition to water-soluble polymers such as sodium alginate, gelatin, and casein, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid ester, polybutyl methacrylate, vinyl chloride / vinyl acetate copolymer, ethylene / Emulsion such as vinyl acetate copolymer, latex such as styrene / butadiene copolymer, styrene / butadiene / acrylic copolymer.

When the heat-sensitive recording material is obtained according to the present invention, various heat-fusible substances can be used as the sensitivity improver, and specific examples thereof include the following compounds. Fatty acids such as stearic acid and behenic acid, fatty acid amides such as stearic acid amide and palmitic acid amide, fatty acid metal salts such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate and zinc behenate, p-benzyl Biphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, β-benzyloxynaphthalene, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid methyl ester Ester, diphenyl carbonate, terephthalic acid dibenzyl ester, terephthalic acid dimethyl ester,
1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1,2-bis (phenoxy) ethane, 1,2-bis (3-methylphenoxy) ethane, 1,2 -Bis (4-methylphenoxy) ethane, 1,4-bis (phenoxy) butane, 1,4-bis (phenoxy) -2-butene, 1,2-bis (4-methoxyphenylthio) ethane, dibenzoylmethane , 1,4-bis (phenylthio) butane, 1,4-bis (phenylthio)
-2-butene, 1,2-bis (4-methoxyphenylthio) ethane, 1,3-bis (2-vinyloxyethoxy)
Benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- (2-vinyloxyethoxy) biphenyl, p-aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, 1,3-di Benzoyloxypropane, dibenzyl disulfide,
1,1-diphenylethanol, 1,1-diphenylpropanol, p- (benzyloxy) benzyl alcohol, 1,
3-diphenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N
-Octadecylcarbamoylbenzene, oxalic acid dibenzyl ester, 1,5-bis (p-methoxyphenyloxy)
-3-Oxapentane and the like.

Further, in the present invention, if necessary, an auxiliary additive component commonly used in this kind of heat-sensitive recording material, for example,
Fillers, surfactants, lubricants and the like can be used in combination. In this case, as the filler, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, inorganic fine powder such as surface-treated calcium or silica, etc. , Urea-formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, vinylidene chloride resin, and other organic fine powders, and examples of lubricants include higher fatty acids and their metal salts, higher fatty acid amides, and higher fatty acids. Examples thereof include various waxes such as ester, animal, plant, mineral and petroleum wax.

Regarding the layer structure, it may be a single layer or a multilayer, and an over layer, an under layer and a back layer may be provided if necessary.

In the present invention, the amount of the leuco dye, the developer and the sensitizer used is 0.5 to 10.0 parts by weight of the developer and 0.5 to 1.0 part by weight of the sensitizer per 1 part by weight of the leuco dye. 10.0 parts by weight, preferably 1 to 5 parts by weight.

In the heat-sensitive recording material of the present invention, a heat-sensitive layer-forming solution containing the above-mentioned name components is applied to a support such as paper, synthetic paper or plastic film, and dried to form a heat-sensitive layer. Then, it can be manufactured by carrying out a calendar treatment.

[0018]

Next, the present invention will be described in more detail with reference to Examples. All parts and% shown below are based on weight.

Example 1 [Preparation of Dye Dispersion (Liquid A)] 3-Dibutylamino-6-methyl-7-anilinofluorane 20 parts 10% Polyvinyl alcohol 20 parts Water 60 parts A mixture of the above composition was placed in a sand mill. It was crushed for 5 to 10 hours to have an average particle size of 1 μm. [Preparation of color developer dispersion (liquid B)] 1,5-bis- (4-hydroxydiphenylthio) -3-oxapentane 20 parts 2,2′-methylenebis (4-methyl-6-tert-butylphenol) 5 parts 10% aqueous polyvinyl alcohol solution 25 parts water 75 parts The mixture having the above composition was pulverized for 5 to 10 hours using a sand mill to have an average particle diameter of 2 μm. [Preparation of (c) liquid] Styrene-divinylbenzene-based copolymer porous beads 20 parts (MP-X01 manufactured by Mitsubishi Kasei) 10% polyvinyl alcohol 20 parts Water 60 parts The mixture having the above composition is used for 2 to 4 using a sand mill. It was pulverized for an hour to have an average particle size of 2 μm. [Preparation of heat-sensitive liquid] (A) liquid 10 parts (B) liquid 40 parts (c) liquid 30 parts water 20 parts The above heat-sensitive liquid is dried onto 3.0 g / m ² of fine paper having a basis weight of 47 g / m ^2. After coating and drying so as to obtain a heat-sensitive recording paper of the present invention, calendering treatment was carried out.

Examples 2 and 3 The average particle size of the liquid (C) of Example 1 was 0.8 μm and 10 μm.
Thermal recording papers were obtained in the same manner as in Example 1 except that the above was used.

Comparative Examples 1, 2, 3, 4 Styrene-divinylbenzene copolymer porous beads in the liquid (C) of Example 1 were converted into fine powders of calcium carbonate, silica, aluminum hydroxide and urea formalin resin. Thermal recording papers were obtained in the same manner as in Example 1 except that they were replaced.

Using the thermal recording paper of the present invention and the thermal recording paper for comparison obtained as described above, the following quality evaluation was carried out. (1) Dynamic color-developing ... In a thermal printing experimental device having a thin film head manufactured by Matsushita Electronic Components Co., Ltd., head power 0.55 W /
Dot, 1 line recording time 20 ms / line, scanning line density 8 × 3.85 dots / mm under the condition of pulse width 0.
Printing was performed at 2, 0.6, and 1.0 msec, and the print density was measured by Macbeth density RD-914. (2) Sticking test ... Fuji Xerox facsimile telecopier 7005, No. 3 charts were received and the occurrence of sticking was visually observed. Further, the head residue was also visually observed. (3) Heat resistance test, humidity resistance test ... 60 ° C. D of the generated sample obtained with the pulse width of 1.0 msec of the dynamic color development of (1)
Leave for 24 hours in ry, 40 ° C., 90% RH.
The values indicated by are taken as heat resistance and moisture resistance, respectively.

[Equation 1]

[0023]

[Table 1] As is clear from Table 1, the heat-sensitive recording material of the present invention showed sticking, residue adhesion, and sticking as compared with the heat-sensitive recording paper for comparison.
It is extremely useful because of its excellent image reliability.

[0024]

The heat-sensitive recording material of the present invention has effects of no sticking, excellent head matching, high sensitivity and high image reliability.

Claims (3)

[Claims] 1. A heat-sensitive recording material comprising a support and a heat-sensitive coloring layer containing a leuco dye and a color developer as main components,
A heat-sensitive recording material, wherein styrene-divinylbenzene copolymer beads are added to the color forming layer. 2. The heat-sensitive recording material according to claim 1, wherein the amount of the styrene-divinylbenzene copolymer beads added is 2 to 5 parts by weight with respect to 1 part by weight of the leuco dye. 3. The heat-sensitive recording material according to claim 1, wherein the styrene-divinylbenzene copolymer beads have an average particle diameter of 1 to 6 μm.