JP3328864B2 - Thermal recording material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to computer output, printers such as calculators, medical measurement recorders, low-speed and high-speed facsimile machines, automatic ticket vending machines, thermal copying machines, and POS system labels. The present invention relates to a widely used thermosensitive recording material.

[0002]

2. Description of the Related Art Heat-sensitive recording materials utilizing a heat-coloring reaction of a colorless or pale-colored coloring dye (leuco dye) with phenols, organic acids, etc. are disclosed in JP-B-43-4160 and JP-B-45-14039. And published in JP-A-48-27736, and widely used. In general, a heat-sensitive recording sheet is prepared by pulverizing and dispersing a developer such as a leuco dye and a phenolic substance into fine particles, and then mixing the two to form a binder, a filler, a sensitivity improver, a lubricant, and other auxiliaries. The coating liquid obtained by the addition is applied to a support such as paper or film, and a color record is obtained by an instantaneous chemical reaction caused by heating. A thermal printer with a built-in thermal head, a facsimile or the like is used for heating such a heat-sensitive recording material for coloring. Such a recording material is capable of performing recording in a relatively short time without performing complicated processing such as development and fixing as compared with other recording materials, has no noise, and has a relatively low noise. Due to its advantages such as low cost, books, documents, etc. can be copied,
It is widely used as information for facsimile, telex, medical measuring instruments, etc. and as a recording material for measuring instruments. However, the conventional heat-sensitive recording material using a combination of a leuco dye and a phenolic substance easily develops a color of the background when stored at a high temperature (that is, is inferior in heat resistance). There is a problem that a high color density cannot be obtained (that is, thermal sensitivity is inferior).

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material which overcomes the drawbacks of the prior art, has excellent heat resistance, and has sufficient heat sensitivity characteristics.

[0004]

According to the present invention, there is provided a heat-sensitive recording material comprising a support and a thermosensitive coloring layer containing a leuco dye and a developer, wherein the developer has the following general formula (I): The problem is solved by using the fluorine-containing bisphenol compound represented by I).

Embedded image (Wherein, X represents a hydrogen atom or a fluorine atom)

[0005] Further, by using the color developer and providing an intermediate layer containing fine plastic spherical hollow particles made of a thermoplastic resin between the support and the thermosensitive coloring layer, a more excellent thermosensitive recording material can be obtained. Provided.

[0006] The intermediate layer of the present invention, which is mainly composed of plastic hollow spherical particles, acts as a heat insulating layer, improves sensitivity by efficiently utilizing heat energy from a thermal head or the like, and further has an average particle diameter of the hollow plastic particles. Is 2
When the thickness is 10 μm and the hollow ratio is 90% or more, the flexibility is further improved, the adhesion to the head is improved, and the dot reproducibility is improved.

The hollow particles used in the heat-sensitive recording material of the present invention (hereinafter, also simply referred to as a recording material) have a shell of a thermoplastic resin and contain air or other gas inside, and have already been foamed. Fine hollow particles having an average particle diameter of 2 to 10 μm, more preferably
It is preferably 3 to 6 μm. This average particle diameter (particle outer diameter)
Is smaller than 2 μm, there is a problem in production such as difficulty in obtaining an arbitrary hollow ratio. Conversely, if it is larger than 10 μm, the smoothness of the surface after coating and drying is reduced. Adhesion is reduced, and the effect of improving sensitivity is reduced. Accordingly, it is preferable that such a particle distribution has a particle diameter in the above-mentioned range and a uniform particle diameter having a small distribution peak. Further, the minute hollow particles used in the present invention preferably have a hollow ratio of 50% or more, particularly preferably 90% or more, from the viewpoint of the heat insulating effect. When the hollow ratio is low, the heat insulating effect is insufficient, so that thermal energy from the thermal head is released to the outside of the thermosensitive recording material through the support, and the sensitivity improving effect is poor. Here, the hollow ratio is a ratio of the outer diameter to the inner diameter of the hollow particles, and is represented by the following formula. Hollow ratio = A / B × 100 (%) A: Inner diameter of hollow particles B: Outer diameter of hollow particles The fine hollow particles used in the present invention have a shell of a thermoplastic resin as described above. Examples of the resin include copolymer resins mainly containing vinylidene chloride and acrylonitrile, polyolefin resins such as polyethylene, polypropylene, and ethylene / propylene copolymer, as well as polyester, polyamide (nylon), acrylic resin, and ABS. Resins, MBS resins, vinyl chloride resins, styrene / acrylic copolymers, and the like. Among these resins, vinylidene chloride is particularly preferred from the viewpoint of ease of production such as uniform particle diameter of hollow particles. And acrylonitrile-based copolymer resins are preferred.

In the present invention, an inorganic or / and organic pigment is optionally used for the intermediate layer. In this case, the pigment is preferably 30 ml / 100 g or more, preferably 8 g or more.
Items of 0ml / 100g or more are selected. These inorganic or /
As the organic pigment, one or more of pigments commonly used in this type of heat-sensitive recording material can be selected. Specific examples thereof include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, surface-treated inorganic pigments such as calcium and silica, and urea-formalin resin. And organic pigments such as styrene / methacrylic acid copolymer and polystyrene resin. The content of the inorganic or / and organic pigment in the intermediate layer is from 0 to 50% by weight,
Preferably it is 0 to 20% by weight.

The leuco dyes used in the present invention may be used alone or as a mixture of two or more kinds. As such leuco dyes, those applied to this type of recording material may be arbitrarily applied. Phenylmethanephthalide type, triallylmethane type, fluoran type, phenothidian type, thiofluoran type, xanthene type, indophthalyl type, spiropyran type, azaphthalide type, chromenopyrazole type, methine type, rhodamine anilinolactam type,
Leuco compounds such as rhodamine lactams, quinazolines, diazaxanthenes, and bislactones are preferably used. Examples of such compounds include, for example, those shown below.

3,3-bis (p-dimethylaminophenyl) -phthalide, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) -6-chlorophthalide, 3,3-bis (p-dibutylaminophenyl) phthalide, 3-cyclohexialamino-6-chlorofluoran, 3-dimethylamino-
5,7-dimethylfluoran, 3- (N-methyl-N-
Isoamylamino) -6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isobutylamino) -6
-Methyl-7-anilinofluoran, 3- (N-p-tolyl-N-ethylamino) -6-methyl-7-anilinofluoran, 3- (N-methyl-N-amylamino)-
6-methyl-7-anilinofluoran, 3- (N, N-
Di-n-amylamino) -6-methyl-7-anilinofluoran, 3- (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluoran, 3- (N
-Methyl-N-iso-propylamino) -6-methyl-7-anilinofluoran, 3- (N-ethyl-N-tetrahydrofurylamino) -6-methyl-7-anilinofluoran, 3-diethylamino -7,8-benzfluorane, 3-diethylamino-7-chlorofluoran,
3-diethylamino-7-methylfluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-
Pyrrolidino-6-methyl-7-anilinofluoran, 3
-Diethylamino-6-methyl-7- (m-trichloromethylanilino) fluoran, 3-diethylamino-7
-(O-chloroanilino) fluoran, 3-dibutylamino-7- (o-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-anilinofluoran,
3-dibutylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (2 ′,
4'-dimethylanilino) fluoran, 3- (N, N-
Diethylamino) -5-methyl-7- (N, N-dibenzylamino) fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrrospirane, 6'-bromo-3'-methoxy-
Benzoindolino-pyrrospirane, 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- (2'-methoxy-4'-dimethylaminophenyl) -3- (2'-hydroxy-4'-
Chloro-5'-methylphenyl) phthalide, 3-morpholino-7- (N-propyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7-trifluoromethylanilinofluoran, 3-diethylamino-5-chloro -7- (N-benzyl-trifluoromethylanilino) fluoran, 3-pyrrolidino-7- (di-p-chlorophenyl) methylaminofluoran, 3-diethylamino-5-chloro-7- (α-phenylethylamino )
Fluoran, 3- (N-ethyl-p-toluidino) -7
-(Α-phenylethylamino) fluoran, 3-diethylamino-7- (o-methoxycarbonylphenylamino) fluoran, 3-diethylamino-5-methyl-
7- (α-phenylethylamino) fluoran, 3-diethylamino-7-piperidinoaminofluoran, 2-
Chloro-3- (N-methyltoluidino) -7- (p-N
-Butylanilino) fluoran, 3,6-bis (dimethylamino) fluorenespiro (9,3 ')-6'-dimethylaminophthalide, 3- (N-benzyl-N-cyclohexylamino) -5,6-benzo- 7-α-naphthylamino-4′-bromofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3- (N-ethyl-N-2-ethoxypropylamino) -6-methyl-7 -Anilinofluoran, 3- (N-ethyl-N-tetrafurfurylamino) -6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-mesitidino-4 ', 5'- Benzofluorane, 3- (p-dimethylaminophenyl) -3- {1,1-bis (p-dimethylaminophenyl) ethylene-2-yl} phthalide, 3- (p-dimethyl Minofeniru) -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-dimethylamino Phenyl) -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-butadien-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, bis (p-dimethylaminostyryl) -1-p-tolylsulfonylmethane and the like.

In order to produce the heat-sensitive recording material of the present invention, the leuco dye, the compound of the present invention as a color developer and other auxiliaries may be supported on a support. As the binder in this case, various conventional binders can be used in an appropriate amount, and specific examples thereof include the following. Polyvinyl alcohol, starch and derivatives thereof, methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose,
Cellulose derivatives such as ethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, acrylamide / acrylate / methacrylic acid terpolymer, styrene /
Maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, water-soluble polymers such as polyacrylamide, sodium alginate, gelatin, casein, polyvinyl acetate, polyurethane, polyacrylate, poly Emulsions such as methacrylates, vinyl chloride / vinyl acetate copolymers, ethylene / vinyl acetate copolymers, and latexes such as styrene / butadiene / acrylic copolymers.

In the present invention, various heat-fusible substances can be used in combination as a sensitivity enhancer, and specific examples thereof include the following, but are not limited thereto. 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 fatty acids such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate and zinc behenate; p-benzylbiphenyl, terphenyl, triphenylmethane, p
-Benzyl benzyloxybenzoate, β-benzyloxynaphthalene, phenyl β-naphthoate, phenyl 1-hydroxy-2-naphthoate, methyl 1-hydroxy-2-naphthoate, diphenyl carbonate, greyacol carbonate, dibensil terephthalate , Dimethyl terephthalate, 1,4-dimethoxynaphthalene, 1,4-
Diethoxynaphthalene, 1,4-dibenzyloxynaphthalene, 1,2-diphenoxyethane, 1,2-bis (3
-Methylphenoxy) ethane, 1,2-bis (4-methylphenoxy) ethane, 1,4-diphenoxybutane,
1,4-cyphenoxy-2-butene, 1,2-bis (4-
Methoxyphenylthio) ethane, dibenzoylmethane,
1,4-diphenylthiobutane, 1,4-diphenylthio-2-butene, 1,3-bis (2-vinyloxyethoxy) benzene, 1,4-bis (2-vinyloxyethoxy) benzene, p- ( 2-vinyloxyethoxy) biphenyl, p-aryloxybiphenyl, p-propargyloxybiphenyl, dibenzoyloxymethane, dibenzoyloxypropane, dibenzyldisulfide,
1,1-diphenylethanol, 1,1-diphenylpropanol, p-benzyloxybenzyl alcohol,
1,3-phenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene,
N-octadecylcarbamoylbenzene, 1,2-bis (4-methoxyphenoxy) propane, 1,5- (4-
Methoxyphenoxy) -3-oxapentane, dibenzyl oxalate, bis (4-methylbenzyl) oxalate, bis (4-chlorobenzyl) oxalate and the like.

When a thermosensitive recording material is to be obtained according to the present invention, it is necessary to add a leuco dye, a color developing agent and the compound of the present invention together with optional components commonly used in this type of thermosensitive recording material, such as fillers and surfactants. Agents, lubricants, pressure color development inhibitors and the like can be used in combination. In this case, as a filler, for example, inorganic fine powders such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, surface-treated calcium and silica, and urea Organic fine powders such as formalin resin, styrene / methacrylic acid copolymer, polystyrene resin, and vinylidene chloride resin; and examples of the lubricant include higher fatty acids and metal salts thereof, higher fatty acid amides and higher fatty acid esters. And various animal, vegetable, mineral or petroleum waxes.

In the present invention, a layer containing a pigment, a binder, a heat-fusible substance or the like can be provided between the intermediate layer and the heat-sensitive coloring layer, if necessary, as another intermediate layer. Further, the recording material of the present invention may improve the storage stability of the recorded image, or may be provided with a protective layer on the heat-sensitive recording layer for the purpose of improving the writability of the recording material. As the components constituting the protective layer, the above-mentioned pigments, binders, heat-fusible substances and the like can be used. Various materials having a solid surface are used as the support used in the present invention. As such,
For example, paper, synthetic paper, plastic film, laminate of plastic film and paper and the like can be mentioned.

Further, for the purpose of improving the storage stability of the recorded image, various compounds having electron accepting properties, such as phenolic compounds, thiophenolic compounds, and thiourea, are used as other color developing agents in the thermosensitive coloring layer. Derivatives, organic acids and metal salts thereof can be used, and specific examples thereof include, but are not limited to, the following. The ratio of these other developers to the developers used in the present invention is preferably 5: 1 to 0: 1 by weight.

4,4'-isopropylidenediphenol, 4,4'-isopropylidenebis-o-methylphenol, 4,4'-sec-butylidenebisphenol, 4,4'isopropylidenebis (2-tert- Butylphenol), zinc p-nitrobenzoate, 1,3,
5-tris (4-tert-butyl-3-hydroxy-
2,6-dimethylbenzyl isocyanuric acid, 2,2-
(3,4'-dihydroxyphenyl) propane, bis (4-hydroxy-3-methylphenyl) sulfide,
4- [β- (p-methoxyphenoxy) ethoxy] salicylic acid, 1,7-bis (4-hydroxyphenylthio)
-3,5-dioxaheptane, 1,5-bis (4-hydroxyphenylthio) -3-oxapentane, monobenzyl phthalate monocalcium salt, 4,4'-cyclohexidene diphenol, 4,4 ' -Isopropylidenebis (2-chlorophenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4'-butylidenebis (6-tert-butyl-2-methylphenol), 1, 1,3-Tris (2
-Methyl-4-hydroxy-5cyclohexylphenyl) butane, 4,4'-thiobis (6-tert-butyl-2-methylphenol), 4,4'-diphenolsulfone, 4-isopropoxy-4'-hydroxy Diphenylsulfone, 4-benzyloxy-4'-hydroxydiphenylsulfone, 4,4'-cyclophenolsulfoxide, isopropyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, benzyl protocatechuate,
Stearyl gallate, lauryl gallate, octyl gallate, 1,3-bis (4-hydroxyphenylthio) propane, N, N'-diphenylthiourea, N, N'-di (m-chlorophenyl) thiourea, salicyl Anilide,
Methyl bis- (4-hydroxyphenyl) acetate, benzyl bis (4-hydroxyphenyl) acetate, 1,3-bis (4-hydroxyphenyl) benzene, 1,4-bis (4-hydroxyphenyl) benzene, 2,4 '-Diphenol sulfone, 2,2'-diallyl-4,4'-hydroxyphenyl sulfone, 3,4-dihydroxy-4
'-Methyldiphenylsulfone, 1-acetyloxy-
Zinc 2-naphthoate, zinc 2-acetyloxy-3-naphthoate, zinc 2-acetyloxy-1-naphthoate,
α, α-bis (4-hydroxyphenyl) -α-methyltoluene, antipyrine complex of zinc thiocyanate, tetrabromobisphenol A, tetrabromobisphenol S, 4,4′-thiobis (2-methylphenol),
4,4'-thiobis (2-chlorophenol) and the like.

[0017]

Next, the present invention will be described in more detail by way of examples. All parts and percentages shown below are based on weight.

Example 1 The following mixtures were pulverized and dispersed in a magnetic ball mill for 2 days to prepare [Solution A], [Solution B] and [Solution C]. [Solution A] 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluorane 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [Solution B] 3,3'-difluoro -4,4'-dihydroxytetraphenylmethane [Compound of the formula (I) where X = H] 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts [Solution C] Calcium carbonate 20 parts Methyl cellulose 20 parts Water 60 parts Next, 10 parts of [Solution A], 30 parts of [Solution B], 40 parts of [Solution C] and 10 parts of a dispersion of zinc stearate (trade name: Hydrin Z-730, 30% concentration) manufactured by Chukyo Yushi Co., Ltd. were mixed and heat-sensitive. A color-forming layer forming liquid was applied to a surface of a commercially available high-quality paper (basis weight: 52 g / m2) so that the adhesion amount after drying was 0.5 g / m2, and dried to form a thermosensitive color-forming layer. So that its surface smoothness is 500-600 seconds To prepare a heat-sensitive recording material (a) the surface is subjected calendered.

Example 2 A heat-sensitive recording material (b) was prepared in the same manner as in Example 1 except that the following [Solution D] was used instead of the [Solution B]. [D solution] 3,3 ', 5,5'-Tetrafluoro-4,4'-dihydroxytetraphenylmethane [Compound of general formula (I) where X = F] 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts

Example 3 The following mixture was stirred and dispersed to obtain an intermediate layer forming liquid [Solution E]. [E liquid] Micro hollow particle dispersion (HP-91 manufactured by Rohm and Haas Co .; copolymer resin mainly composed of styrene and acrylic, 30 parts, solid content concentration 38%, average particle diameter 0.7 μm, hollow ratio 80%) Styrene / butadiene copolymer latex (solid content: 47.5%) 10 parts Water 60 parts The above-mentioned intermediate layer forming solution is dried on a surface of a commercially available high-quality paper (basis weight: 52 g / m2) to a weight of 5 g / m2. Coating and drying were performed to obtain an intermediate layer coated paper. Next, the thermosensitive coloring layer forming liquid obtained in Example 1 was applied and dried on the intermediate layer so that the amount of dye after drying was 0.5 g / m2, and a thermosensitive coloring layer was provided. The surface of the layer was calendered so as to have a degree of 500 to 600 seconds to prepare a heat-sensitive recording material (c).

Example 4 A heat-sensitive recording material (d) was prepared in the same manner as in Example 3 except that the liquid used in Example 2 was used as the heat-sensitive coloring layer forming liquid.

Comparative Example 1 A heat-sensitive recording material (e) was prepared in the same manner as in Example 1 except that the following [Solution F] was used instead of [Solution B]. [Solution F] Bisphenol A 20 parts 10% aqueous solution of polyvinyl alcohol 20 parts Water 60 parts

Comparative Example 2 A heat-sensitive recording material (f) was prepared in the same manner as in Example 3 except that the liquid for forming a heat-sensitive coloring layer in Comparative Example 1 was used.

The heat-sensitive recording materials (a) to (f) prepared as described above are printed by a thermal paper color tester manufactured by Okura Electric Co., Ltd., and the color density is measured by a Macbeth densitometer RD-914.
Was measured. Also, 100 ℃ per background density
The concentration before and after the 16-hour heat resistance test was determined by Macbeth R
The concentration was measured by D-14. Table 1 shows the results.

[0025]

[Table 1] Applied power: 0.45W / dot, line cycle: 8msec / line

[0026]

The heat-sensitive recording material of the present invention is excellent in heat resistance and has sufficient heat sensitivity characteristics. By providing the heat-sensitive recording material of the present invention on an intermediate layer containing plastic fine hollow particles on a support, more excellent performance is exhibited.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-1222782 (JP, A) JP-A-6-1742 (JP, A) JP-A-2-80287 (JP, A) JP-A-5-1982 85060 (JP, A) JP-A-6-247047 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/28-5/34

Claims (2)

(57) [Claims] 1. A thermosensitive recording material comprising a support and a thermosensitive coloring layer containing a leuco dye and a developer, wherein a fluorine-containing bisphenol compound represented by the following general formula (I) is used as the developer. A thermosensitive recording material characterized by being used. Embedded image (Wherein, X represents a hydrogen atom or a fluorine atom) 2. A thermosensitive recording comprising a support having an intermediate layer containing thermoplastic hollow spherical particles made of a thermoplastic resin, and a thermosensitive coloring layer containing a leuco dye and a developer on the intermediate layer. A heat-sensitive recording material, characterized in that a fluorine-containing bisphenol compound represented by the general formula (I) is used as the developer.