JPH0712736B2 - Heat-sensitive or pressure-sensitive recording material - Google Patents

Description

The present invention relates to a heat-sensitive or pressure-sensitive recording material, and more particularly to a heat-sensitive or pressure-sensitive recording material containing a specific phenol compound as a developer.

The thermosensitive recording medium is usually produced by applying a colorless or light-colored color-forming substance and a developer in a separated state together with a binder and other additives to the surface of the base paper. Then, in the recording apparatus, when a heating element such as a thermal head or a heating pen comes into contact with the recording body, the dye and the color developer react with each other to develop a color such as black, and recording is performed.

Further, the pressure-sensitive recording material is used, for example, as a pair of sheets in which a sheet containing a microcapsulated color-forming substance and a sheet containing a color developer are stacked. Then, the microcapsules are broken by writing pressure or the like, the color-developing agent is transferred to the adjacent sheet containing the color-developing agent, and the color is developed and recorded.

Conventionally, phenol-based compounds have been used as color developers, such as bisphenol A, 4,4′-cyclohexylidene diphenol, 1,1,3-tris (3′-tertiary butyl-4 ′). -Hydroxy-6'-methylphenyl)
Butane, p-hydroxybenzoic acid ester and the like have been used, but when these phenols are used, there is a defect that color unevenness occurs or discoloration occurs during storage.

As a result of intensive studies to solve these drawbacks, the present inventor has found that a specific phenol compound exerts an excellent effect as a color developer, and arrived at the present invention.

That is, the present invention provides a heat-sensitive or pressure-sensitive recording material, characterized in that the coloring reaction system contains a compound represented by the following formula (I) as a developer for developing a color-forming substance. To do.

(In the formula, R ₁ represents a hydrogen atom, an alkyl group or an aryl group, and R ₂ represents an alkyl group, an alkoxy group or an aryl group.) In the compound represented by the general formula (I) used in the present invention, Examples of the alkyl group represented by R ₁ and R ₂ include methyl, ethyl, propyl, butyl, isobutyl, sec-butyl, tert-butyl, octyl, 2-ethylhexyl, isooctyl, decyl, dodecyl, tridecyl, heptadecyl, octadecyl and the like. Examples of the aryl group include phenyl, naphthyl, methylphenyl, butylphenyl, methoxyphenyl and the like. As the alkoxy group, methoxy, ethoxy, isopropoxy,
Examples include butoxy and octoxy.

In addition, the compound represented by the general formula (I) has a keto-enol tautomer, and may of course be an enol compound.

Examples of the compound represented by the general formula (I) include diacetyl methane, dipropionyl methane, dipivaloyl methane, acetyl propionyl methane, benzoyl formyl methane, benzoyl acetyl methane, pivaloyl benzoyl methane, stearoyl benzoyl methane, and diaromatic benzoyl methane. It can be easily produced by reacting a β-diketone compound such as benzoylmethane, ethyl acetoacetate, or ethyl benzoylacetate with a dicarbonyl compound such as a β-ketoester compound with p-aminophenol.

Next, specific synthesis examples of the phenol compound used in the present invention will be shown, but the present invention is not limited by the following synthesis examples.

Synthesis example 4- (1'-methyl-3'-oxobutylideneimino)
Synthesis of phenol 60 ml of ethanol, 22 g of p-aminophenol and 24 g of diacetylmethane were taken and stirred under reflux for 5 hours. The reaction solution was initially heterogeneous, but gradually became homogeneous and became a brown transparent liquid.

A slight amount of insoluble matter was filtered while hot and cooled to room temperature to precipitate pale yellow crystals.

This was filtered and dried to obtain a product of pale yellow crystals having a melting point of 150 ° C.

The compound represented by the general formula (I) can of course be used alone as a developer for a heat-sensitive or pressure-sensitive recording material, but depending on its use and required performance, a conventionally used developer can be used. Agents: p-octylphenol, pt-butylphenol, p-phenylphenol, bisphenol A,
1,1-bis (p-hydroxyphenylbutane), 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, p-hydroxybenzoic acid, ethyl p-hydroxybenzoate, butyl p-hydroxybenzoate , Benzyl p-hydroxybenzoate, 3,5-di-t-butylsalicylic acid, 4,4'-cyclohexylidenediphenol, p-hydroxydiphenoxide, α-naphthol, β-naphthol, p-hydroxyacetophenone, p- t-octylcatechol, 2,2'-hydroxybiphenyl, 2,2-bis (3-methyl-4-hydroxyphenyl) propane,
2,2-bis (3,5-dimethyl-4-hydroxyphenyl)
It can also be used in combination with a phenol such as propane or an organic acid.

Various dyes are well known as the color-developing substance used in the present invention, and are not particularly limited as long as they are used for general pressure-sensitive recording paper or heat-sensitive recording paper.

Specific examples of these dyes include (1) triarylmethane compounds; for example, 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone), 3- (p -Dimethylaminophenyl) -3- (1,2-dimethyl-3-indolyl) phthalide, 3- (p-dimethylaminophenyl)-
3- (2-phenyl-3-indolyl) phthalide, 3,3
-Bis (9-ethyl-3-carbazolyl) -5-dimethylaminophthalide, 3,3-bis (2-phenyl-3-indolyl) -5-dimethylaminophthalide, etc., (2) diphenylmethane compound; , 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, etc. (3) Xanthene compound;
For example, rhodamine-β-anilinolactam, 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7- (2-chloroanilino) fluorane,
3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7- (β-ethoxyethylamino) fluorane, 3-piperidino-6
-Methyl-7-anilinofluorane, 3-ethyl-tolylamino-6-methyl-7-anilinofluorane, 3-
Cyclohexylmethylanilino-6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7
(4) thiazine compounds such as -γ-chloropropylaminofluorane; for example, benzoyl leuco methylene blue, p-nitrobenzoyl leuco methylene blue, etc.
(5) Spiro compounds; for example, 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho (3-
Examples thereof include methoxybenzo) spiropyran, and these dyes can be used as a mixture of several kinds.

The above-mentioned color developer and color-developing dye are atomized by a grinder such as a ball mill, an attritor, a sand grinder or an appropriate emulsifying device, and various additive materials are added according to the purpose to prepare a coating liquid.

This coating solution usually contains polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, starches, a binder such as a styrene-maleic anhydride copolymer, a vinyl acetate-maleic anhydride copolymer, a styrene-butadiene copolymer, kaolin and the like. , Diatomaceous earth, talc, titanium dioxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, etc. are mixed, but in addition to this, metal soaps such as zinc stearate, waxes, light stabilizers, water resistance agents, dispersions Agents, defoamers and the like can be used. A desired heat-sensitive or pressure-sensitive recording material can be obtained by applying this coating liquid to paper and various films.

The amount of the specific phenol compound used in the present invention is determined according to the required performance and recording suitability and is not particularly limited, but 1 to 10 parts of the phenol compound is usually used for 1 part of the color forming dye. .

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example-1 20 g of 3-diethylamino-6-chloro-7-anilinofluorane was ground in a ball mill together with 100 g of a 10% aqueous polyvinyl alcohol solution to obtain a dye dispersion. (Solution A) Similarly, 20 g of the sample (see Table 1) was ground together with 100 g of a 10% aqueous polyvinyl alcohol solution in a ball mill to obtain a developer dispersion. (Liquid B) Liquid A and liquid B were mixed at a ratio of 3:10, and 50 g of calcium carbonate was added to 200 g of the mixed liquid and dispersed to obtain a coating liquid.

This coating liquid was applied onto a base paper of 50 g / m ² so that the coating amount of the solid content was 6 g / m ² , and dried.

The obtained thermal paper was used to measure the density of the background and the density of the printed part after printing with a commercially available thermal fax machine (NEFAX-3000: manufactured by NEC) using a Macbeth densitometer RD-514 type.

Also, this color development body was stored for 48 hours under two conditions of a temperature of 50 ° C., a humidity of 90% and a temperature of 70 ° C. and a dry state, and the background density and the density of the printed part after the storage were measured in the same manner. From the formula, the residual rate of the density of the printed portion after storage was measured.

The results are shown in Table-1.

Example-2 20 g of 3-diethylamino-6-chloro-7- (β-ethoxyethyl) aminofluorane was ground in a ball mill together with 100 g of a 10% aqueous solution of polyvinyl alcohol to obtain a dye dispersion liquid. (Solution A) Similarly, 10 g of 2,2-bis (4-hydroxyphenyl) propane and 10 g of stearic acid amide were ground in a ball mill together with 100 g of a 10% aqueous polyvinyl alcohol solution to obtain a dispersion liquid. (Solution B) Similarly, 20 g of the sample compound was ground together with 100 g of a 10% aqueous solution of polyvinyl alcohol in a ball mill to obtain a dispersion liquid. (C liquid) A liquid, B liquid and C liquid are mixed at a weight ratio of 3: 20: 5 to form a mixed liquid.
50 g of calcium carbonate was added to 200 g and dispersed to obtain a coating liquid.

Using this coating liquid, a thermal paper was prepared in the same manner as in Example 1, and the same test as in Example-1 was conducted.

The results are shown in Table-2.

Example 3 4- (1'-methyl-3'-oxobutylidene imino)
Phenol 10 parts, China clay 30 parts, styrene / butadiene copolymer 10 parts and water 70 parts were mixed and ground in a ball mill to a particle size of 2 to 4 microns.

The obtained dispersion was applied onto a 50 g / m ² base paper using a doctor blade so that the amount of the dispersion was 6 g / m ² .

This coated paper was used as a transfer sheet, and was overlaid with a commercially available carbon paper (containing crystal violet lactone in microcapsules) and printed with a typewriter. As a result, a dark blue copy was obtained.

Claims (1)

[Claims] 1. A heat-sensitive or pressure-sensitive recording material, characterized in that the coloring reaction system contains a compound represented by the following formula (I) as a developer for developing a color-forming substance. (In the formula, R ₁ represents a hydrogen atom, an alkyl group or an aryl group, and R ₂ represents an alkyl group, an alkoxy group or an aryl group.)