JPS59159394A - Thermal recording material - Google Patents

Abstract

PURPOSE:To improve adaptability to a head, by a method wherein a specified fluoran compound having amino groups is used as a leuco dye and a specified dispersant is used in a thermal recording material comprising a leuco dye and a phenolic substance. CONSTITUTION:A fluoran compound of the formula (wherein each of R1-R4 is hydrogen, alkyl, cycloalkyl or the like; each of R5 and R6 is hydrogen, halogen, alkyl or the like; each of X and Y is halogen, alkyl or the like; n is 0-2; m is 0-4) having substituted or unsubstituted amino groups at least at positions 3 and 7, is pulverized and dispersed in the presence of a carboxyl-modified polyvinyl alcohol as a dispersant, and is applied onto a base together with a known phenolic substance as a color developer, a binder, additives or the like. The carboxyl-modified polyvinyl alcohol is used in an amount of 2-20pts.wt. per 100pts.wt. of the fluoran compound and serves also as a binder.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a color-forming reaction between a leuco dye and a color developer, and more specifically, to a color-forming reaction between a leuco dye and a color developer, and more specifically, a color-forming reaction between a leuco dye and a color developer, and more specifically, a color-forming reaction between a leuco dye and a color developer. This invention relates to a heat-sensitive recording material that utilizes a color-forming reaction with a phenolic substance.

[Prior art]

Thermosensitive recording materials are recording materials that have a structure in which a so-called thermosensitive coloring layer that develops color when heated is formed on a support such as paper, synthetic paper, or resin film. etc. are used. Compared to other recording materials, such recording materials can produce records in a relatively short time without complex processes such as development and fixing.
Due to the fact that it does not generate noise and is relatively inexpensive, it is widely used not only for copying books and documents, but also as a recording material for various information and measuring instruments such as electronic computers, facsimiles, telex machines, medical measuring instruments, etc. It is used.

In recent years, the demand for high-speed and high-density recording of image information has increased, and to meet this demand, heat-sensitive recording materials that have a heat-sensitive coloring layer containing a leuco dye and a color developer on a support are widely used. . Among such heat-sensitive recording materials,
Fluoran compounds having substituted or unsubstituted amino groups in at least the 3- and 7-positions are used as leuco dyes, and various phenolic substances are used as color developers to reduce blurring of the background and fading of recorded images. In addition, it is known to show relatively good results in terms of high color development and high whiteness. However, in the case of this heat-sensitive recording material, staking and residue adhesion occur, and the compatibility with the thermal head is still unsatisfactory.

〔the purpose〕

The present invention provides a heat-sensitive recording material in which a support L is provided with a heat-sensitive coloring layer containing a fluoran compound having substituted or unsubstituted amino groups at least at the 3-position and the 7-position, and a phenolic substance, in which sticking and residue adhesion are prevented. The object of the present invention is to provide a heat-sensitive recording material that has excellent compatibility with a thermal head.

〔composition〕

According to the present invention, in a support provided with a heat-sensitive coloring layer containing a leuco dye and a phenolic substance, the leuco dye is a fluoran compound having substituted or unsubstituted amino groups at least at the 3- and 7-positions. In addition to using
A heat-sensitive recording material characterized in that carboxyl group-modified polyvinyl alcohol is used as a dispersant for the fluoran compound.

is provided.

The leuco dye used in the present invention is a fluoran compound having substituted or unsubstituted amino groups at least at the 3rd and 7th positions.
It is disclosed in Publication No. 4. Such leuco dyes are
It is expressed by the following general formula.

In the above formula, Rl, R2, R3 and R+ are hydrogen, an alkyl group, an alicyclic group, an aryl group, an aralkyl group, and these further include a halogen, an alkyl group, a halogenated alkyl group, an alicyclic group, an aryl group, an aralkyl group. , represents a group substituted with a hydroxy group, an alkoxy group, an acyl group, an amino group, a substituted amino group, or a nitro group, and R1 and R2, R3 and R can also form a ring with each other. R is hydrogen, halogen,
Indicates an alkyl group, a halogenated alkyl group, an alkoxy group, an aralkyl group, and a substituted amino group. R represents hydrogen, halogen, alkyl group, halogenated alkyl group, or aralgyl group. X represents a halogen, an alkyl group, a halogenated alkyl group, or an alkoxy group; 6Y represents a halogen, an alkyl group, an alicyclic group, a halogenated alkyl group, an alkoxy group, an aralkyl group, an aryl group, an acyl group, an amino group, or a substituted amino group; , indicates a nitro group. n is O~2 (integer), m is 0~
Indicates 4 (integer).

Specific examples of the fluoran compound include those shown below.

3-diethylamino-6-methyl-7-mesitidino 4
',5'-Benzofluorane, 3-diethylamino-6
-Methyl-7-pendylamino-4',5'-benzofluorane, 3-(N-methylanilino)-5,6-benzo7-phenoxyphenylaminofluorane, 3-(
N-methylanilino)-5,6-benzo7-(0-methyl-phenoxyphenyl)aminofluorane, 3-(
N-methylanilino)-5,6-benzo7-(m-methoxyphenoxyphenyl)aminofluorane, 3-
(N-methyl1012trophenyl)amino5.6-
Benzo-7-phenoxyphenylamino-4'-methylfluorane, 3-(N-ethyl-methoxylponylphenyl)amino-5,6-benzo-7-phenoxyphenylaminofluorane, 3-α-naphthyl Amino
5,6-benzo7-phenoxyphenylaminofluorane, 3-(N-penzylanilino)-5,6-benzo7-phenoxyphenylamino-3',4',5',
6'-tetracyclofluorane, 3-(N-pendyl-hexylamino)-5,6-benzo7-α-naphthylamino-4'-bromofluorane,: {-(N-methyl-cyclohexylamino)-5- Chloro-6-methyl-7-anilinofluorane, 3-(N-p-methylbenzyl-hexylamino)-5=methoxy-7
-anilinofluorane, 3-(N-α naphthylmethyl-cyclohexylamino)-7-nitropendylaminofluorane, 3-(N-methyl-cyclohexylamino)-7-anilino-4'-nitrofluorane, 3-diethylamino-7-biperidinofluorane, 2-methyl-
3-ethylamino-5,6-benzo-7-anilinofluorane, 2-methyl-1-xy-3-dimethylamino-7-dimethylaminofluorane, 3-diethylamino-4-chloro-6-methyl-7-1- Luiginofluorane, 2-
Bromo-3-diethylamino-5,6-benzo-7-phenoxyphenylaminofluorane, 2-chloro-3-
(N-methyltoluidino)-7-(p-n-butylanilino)fluoran, 2-dimethylaminomethyl-3-diethylamino-5-methyl-7-(N-methyl-benzylamino)-4'-dimethylaminofluoran, 2-chloro-3-diethylamino-7-pendylamino-4'
-Methylfluoran, 2-chloro-3-diethylamino-6-methyl-7-anilino 4'-benzylidenefluoran, 3-(N-methyl-phenoxyphenylamino)-5-methyl-7-(p-butylanilino )-47-
Nitrofluorane, 3-(N-methyl-phenoxyphenylamino)-5,6-benzo 7-phenoxyphenylaminofluoran, 3-(N-methoxyethylphenoxyphenylamino)-5.6- Benzo 7-α-naphthylamino-4',6'-dibromofluorane, 3-
Diethylamino-7-(α-phenylethylamino)fluoran, 3-diethylamino-6-methyl-7-(α
-phenylethylamino)fluoran, 3-diethylamino-5-methyl-7-(α-phenylethylamino)
Fluoran, 3-diethylamino-5-methyl-7-(
α-Phenylethylamino)fluoran, 2-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-5-chloro-7
-(α-phenylethylamino)fluoran, 3-dimethylamino-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-p-toluidino)-7-(α
-phenylethylamino)fluorane, 3-(N-methylanilino)-7-(α-phenylethylamino)fluorane, 3-mesitidino 7-(α-phenylethylamino)fluorane, 3-(N-methyl xylidino)-6
-Methyl-7-cyclohexylaminofluorane, 3-
(N-butyl-xylidino)-6-methyl-7-pendylaminofluorane, 3-diethylamino-7-(0-
Methoxyluponylphenylamino)fluorane, 3-
Diethylamino-7-(0-canoleboxyphenylamino)fluorane, 3-pyrrolidino-7-(di-P-chlorophenyl)methylaminofluorane, 3-bi[1lysino-7-(di-P-methylphenyl)methylaminofluoran Oran, 3-pyrrolidino-5-methyl-7-(gyp-
methylphenyl) methylaminofluorane, 3-pyrrolidino-5-ami, no 7-(di-P-methylphenyl)
Methylaminofluorane, 3-methylpiperidino-7-
(G-p-rolfenyl) methylaminofluorane,
3-morpholino 5,6-benzo-7-anilinofluorane, 3-morpholino-5,6-benzo-7-anisidinofluorane, 3-(N-medihexylamino)-5,6-benzo7-α- naphthylamino-4'
-Bromofluorane, 3-(N-pendyl-hexylamino)-5-chloro-7-α-naphthylamino-4
7-Chlorofluorane, etc.

Further, in the present invention, a commonly used phenolic substance is used as a color developer, and specific examples thereof include those shown in 4 below.

gallic acid, salicylic acid, 3-isobrobylsalicylic acid,
3-cyclohexylsalicylic acid, 3,5-di-Lert
．． -butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4'-isozolobylidene diphenol, 4,4'-isobropylidene bis(2-chlorophenol), 4,4'-isobropylidene diphenol Pyridenbis (2,6-
dibromophenol), 4,4'-isobropylidene bis(2,6-dichlorophenol), 4,4'-isobropylidene bis(2-methylphenol), 4,4'-
Isopropylidene bis(2,6-dimethylphenol)
, 4,4'-isobropylidene bis(2-tert-butylphenol), 4,4'-sec-butylidene diphenol, 4,4'-cyclohexylidene bisphenol, 4,4'-cyclohexylidene bis( 2-methylphenol), 4-InetL-butylphenol, 4-
phenylphenol, 4-hydroxydiphenoxide,
α-Naph 1-1, β-naph 1-1, Methyl-4-hydroxybenzoate, 4-hydroxyacetylphenol, Novolac-type fucounol resin, 2,2'-thiobis(4,6-dichlorophenol) Nore), 4-1=er
t-octinole, 2,2'-methylenebis(4-chlorophenol), 2.2'. -methylenebis(4-methyl-6-1:art-butylphenol),
2,2'-dihydrocyphenyl, ethyl p-hydroxybenzoate, probyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlorobenzyl p-hydroxybenzoate,
0-chlorobenzyl p-hydroxybenzoate, p-methylbenzyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, etc.

In the present invention, carboxyl group-modified polyvinyl alcohol is used as a dispersant for the fluoran compound. In this case, the carboxyl group-modified polyvinyl alcohol is fumaric acid,
Those made by reacting carboxylic acids such as maleic acid, itaconic acid, maleic anhydride, phthalic anhydride, trimellitic anhydride, itaconic anhydride, etc., or those made by esterifying these reactants, or vinyl acetate, Saponified polymers with ethylenically unsaturated carboxylic acids such as maleic acid, fumaric acid, and itaconic acid are used. Regarding the manufacturing method of such carboxyl group-modified polyvinyl alcohol, Japanese Patent Publication No. 45-21312 and Japanese Patent Application Laid-open No. 53-91
! ) No. 95, No. 54-28389 and No. 54-28
It is disclosed in each publication of No. 390.

In the present invention, this carboxyl group-modified polyvinyl alcohol is used in a ratio of 2 to 20 parts by weight per 100 parts by weight of the fluoran compound.

In the present invention, this carboxyl group-modified polyvinyl alcohol is applied as a dispersant for the fluoran compound, but in this case, the application method may be the same as conventional methods, such as a ball mill, a colloid mill, an alheterizer, The fluoran compound may be ground and dispersed in the presence of carboxyl group-modified polyvinyl alcohol using a sand grinder or the like. In this case, the fluoran compound is preferably pulverized and dispersed so that its particle size is 5 μm or less, preferably 2 μm or less.

In the present invention, paper, synthetic paper, synthetic resin film, metal laminated paper, etc. are widely used as the support on which the thermosensitive coloring layer is applied.

It is preferable to use a binder when each component to be contained in the thermosensitive coloring layer is provided on a support such as paper. As the binder, widely known binders can be used, and specific examples include the following compounds.

■) Polyvinyl alcohol 2) Methoxycellulose 3) Hydroxycellulose 4) Carboxymethylcellulose 5) Carboxyethylcellulose 6) Polyvinylpyrrolidone 7) Polyacrylamide 8) Polyacrylic acid 9) Starch 10) Gelatin In addition, the carboxyl group-modified polyvinyl alcohol described above is Applied as an adhesive.

In addition, latexes such as styrene-butadiene copolymers, polyvinyl acetate, polyacrylic esters, and polymethacrylic esters such as polybutyl methacrylate can also be used in combination with these water-soluble binders.

By adding fine powders such as silica, magnesia, talc, calcium carbonate, barium sulfate, aluminum stearate, urea-formalin resin, and styrene resin to the heat-sensitive coloring layer, the clarity of the colored image is improved. be able to.

Furthermore, when coating and forming the thermosensitive coloring layer on the support 12, it is possible to add an antifoaming agent, a wetting agent, or a wax to the thermosensitive coloring layer forming liquid to improve coating properties and thermal responsiveness. can.

〔effect〕

The heat-sensitive recording material of the present invention utilizes a color-forming reaction between a specific fluoran compound and a phenolic substance, and uses carboxyl group-modified polyvinyl alcohol as a dispersant for the fluoran compound. In addition to having a white background, it does not cause staking or residue when printing by facsimile, etc., and has significantly improved compatibility with thermal heads.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

Note that all parts and percentages shown below are based on weight.

Example 1 (A) 20 parts of 3-(cyclo\kyzyru-N-methylamino)-6-methynole-7-anilinofluorane 10% aqueous solution of itaconic acid-modified polyvinyl alcohol 20 parts of water 60 parts (B) Liquid bisphenol 20 parts of A, 20 parts of 10% hydroxyedyl cellulose, 60 parts of aqueous solution [C] Solution: 10 parts of stearic acid amide, 20 parts of calcium carbonate, 30 parts of 5% methylcellulose aqueous solution, 40 parts of water, each of the above A, B and C solutions separately. Average particle size 2
The mixture was dispersed in a ball mill so that the particle size was less than 10μ, and then 1 part of liquid A, 4 parts of liquid B, 2 parts of liquid C, and 2 parts of a 10% polyvinyl alcohol aqueous solution were mixed and stirred to prepare a thermosensitive coloring layer forming liquid. . After drying, apply this liquid to a commercially available paper with a basis weight of 52 g/a. After coating and drying, use a super calender to achieve a smoothness of 400 to 50.
A heat-sensitive recording material was obtained by surface treatment to obtain a heat-sensitive recording material.

Example 2 A heat-sensitive recording material was obtained in the same manner as in Example 1 except that 10% maleic acid-modified polyvinyl alcohol was used in place of the 10% itaconic acid-modified polyvinyl alcohol in Solution A.

Example 3 A heat-sensitive recording material was obtained in the same manner as in Example 1, except that 10% fumaric acid-modified polyvinyl alcohol was used instead of the 10% itaconic acid-modified polyvinyl alcohol in Solution A.

Example 4 In Example, 3-diethylamino-7-chlorofluorane was used in place of 3-(N-cyclohexy-N-methylamino)-6-methyl-7-anilinofluorane in Solution A. A heat-sensitive recording material was obtained in the same manner as in Example 1, except for the above.

Comparative Example 1 In [Example], instead of the 10% r taconic acid-modified polyvinyl alcohol aqueous solution in Solution A, L;
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that a ribinyl alcohol aqueous solution was used.

Comparative Example 2 Same as Example 1 except that in Example 1, 10% hydroxyethyl cellulose aqueous solution was used instead of the 10% itaconic acid-modified polyvinyl alcohol aqueous solution in Solution A.
：＋、I got a thermal recording fee.

Comparative Example 3 3-(N-cyclohexyJ-N-
-Methylamino)-6-methyl-7-anilinofluorane was replaced with 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, and 10% itaconic acid was used as a dispersant. A heat-sensitive recording material was obtained in the same manner except that a modified polyvinyl alcohol aqueous solution was used.

Comparative Example 4 3-(N-cyclohexylamino) in Solution A of Example 1
-6-methyl-7-anilinofluorane instead of 3,
A heat-sensitive recording material was obtained in the same manner except that 3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide was used (U) and a 10% aqueous polyvinyl alcohol solution was used as the dispersant.

Comparative Example 5 3,3'-bis(P-di,methylaminophenyl )-6-dimethylamine, nophthalide was used to obtain a heat-sensitive recording stone, except that a 10% aqueous pidroxycellulose solution was used as a dispersant.

Each of the heat-sensitive recording materials obtained in the above manner was recorded using a heat-sensitive facsimile (Refax Model 300 manufactured by I-I), and the image density and background area were measured using a Macbeth Model D-514. , We also observed the condition of the head's scrap 44 arrival. The results are shown in the table below.532

Claims (1)

[Claims] (1) In a support provided with a thermosensitive coloring layer containing a leuco dye and a phenolic substance, a fluoran compound having substituted or unsubstituted amino groups at at least the 3- and 7-positions is used as the leuco dye, and A heat-sensitive recording material characterized in that carboxyl group-modified polyvinyl alcohol is used as a dispersant for the fluoran compound.