JPS63315286A - Thermal recording material - Google Patents

Abstract

PURPOSE:To prevent a matching trouble such as paper jamming from occurring at the time of thermal printing or paper discharge, by providing a back coat layer comprising SnO2 and a quarternary ammonium salt on the back side of a base. CONSTITUTION:A thermal color forming layer is provided on a base, and a protective layer is provided, if necessary, on the color forming layer. A back coat layer comprising SnO2 and a quaternary ammonium salt is provided on the back side of the base. The quarternary ammonium salt may be, for example, an ordinary quarternary ammonium salt or quaternary ammonium type polymer comprising a long chain alkyl group, and is particularly preferably a styrene polymer having an aliphatic quarternary ammonium group, for example, a block copolymer of styrene having a quarternary ammonium group with styrene. The back coat layer can be provided on the back side of the base by dispersing SnO2 and the quarternary ammonium salt in water together with a conventional binder, and applying the dispersed material to the back side of the base, followed by drying.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material whose viewing characteristics are improved by providing a back coat layer on the back side of a support.

[Prior art]

A thermosensitive recording material is a recording material having 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, and a thermal head is used for heating to develop the color. A built-in thermal printer is used. Compared to other recording materials, such recording materials can produce records in a short time using relatively simple equipment without complex processes such as development and fixing, and are less likely to generate noise or pollute the environment. Due to its advantages such as the absence of paper and low cost, it is used not only for copying books and documents, but also as a recording material in a wide range of applications such as electronic computers, facsimile machines, ticket vending machines, labels, and recorders. Thermochromic compositions used in such heat-sensitive recording materials generally consist of a color former and a color developer that causes the color former to develop color when heated. As the color former, for example, a composition having a lactone, lactam or spiropyran ring Colorless or light-colored leuco dyes are used, and various acidic substances such as organic acids and phenolic substances are used as color developers. A recording material that combines a color former and a color developer has the advantage that the resulting image has a particularly clear color tone, a white background, and the image (dye image) has excellent weather resistance. , is widely used.

However, when continuous thermal printing is performed on such heat-sensitive recording materials, static electricity is generated between the heat-sensitive recording materials or between the heat-sensitive edge material and the thermal head, platen roll, or discharge section (tray, saucer, etc.).

Therefore, when paper is fed, paper jams or jams occur in a portion of the tray, which can cause mechanical failure.

In addition, in JP-A-62-35874, the generation of static electricity is suppressed by providing an undercoat layer consisting of a styrene polymer containing a quaternary ammonium group and a wax having a melting point of 60°C or higher. In addition, heat-sensitive recording materials that do not cause paper jams or multilayer feeding have been proposed, but these heat-sensitive recording materials are still unsatisfactory in terms of suppressing static electricity generation under severe environmental changes, especially at low temperatures and low humidity. Ta.

〔the purpose〕

An object of the present invention is to provide a heat-sensitive recording material that does not cause matching troubles such as paper jams and jams during thermal printing and paper ejection under a wide range of environments.

〔composition〕

According to the present invention, in a heat-sensitive recording material comprising a heat-sensitive coloring layer on a support and, if necessary, a protective layer on the heat-sensitive coloring layer, SnO2 and a quaternary ammonium salt are provided on the back surface of the support. Provided is a heat-sensitive recording material characterized in that it is provided with a back coat layer containing.

The heat-sensitive recording material of the present invention has a back coat layer containing SnO2 and quaternary ammonium salt on the back surface of the support, so that it can prevent paper jams and jams during thermal printing and paper ejection under a wide range of environments. This method does not cause problems such as poor matching.

In the present invention, examples of the quaternary ammonium salt to be included in the back coat layer together with SnO2 include quaternary ammonium salts and quaternary ammonium type polymers having ordinary long-chain alkyl groups, and in particular, aliphatic A styrenic polymer having a quaternary ammonium group, such as a block copolymer of styrene and styrene having a quaternary ammonium group, is preferred.

To provide the back coat layer on the back surface of the support.

It can be obtained by dispersing SnO□ and the quaternary ammonium salt in water together with a conventional binder, applying this to the back surface of the support, and drying it.

In the present invention, the binder used in forming the back coat layer is appropriately selected from conventionally known water-soluble polymers and polymer emulsions.

That is, examples of water-soluble polymers include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylamide/acrylic acid ester, etc. Polymer, acrylamide/acrylic acid ester/methacrylic acid terpolymer, styrene/maleic anhydride copolymer alkali salt, isobutylene/maleic anhydride copolymer alkali salt,
Examples include polyacrylamide, sodium alginate, gelatin, casein, and the like. Examples of polymer emulsions include polyvinyl acetate, polyacrylic acid, polyacrylic ester, vinyl chloride/vinyl acetate copolymer,
Emulsions such as polybutyl methacrylate, ethylene/vinyl acetate copolymer, polyurethane resin, and styrene/
Latex such as butadiene copolymer, styrene/butadiene/acrylic copolymer, and the like can be mentioned.

In the present invention, the heat-sensitive color forming layer can be composed mainly of a leuco dye and a color developer capable of reacting with the leuco dye to form a color when heated.

The leuco dyes used in the present invention can be applied singly or in combination of two or more types, but such leuco dyes include:
Those applied to this type of heat-sensitive material can be arbitrarily applied. For example, leuco compounds of dyes such as triphenylmethane-based, fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, and indolinophthalide-based dyes are preferably used. . Specific examples of such leuco dyes include those shown below.

3.3-bis(ρ-dimethylaminoenyl)-phthalide, 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(P -dimethylaminophenyl)-6-dibutylaminophenyl, 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-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'-hlifluoromethylphenyl)amino)-6-dinithylaminofluorane, 2-(3,6
-bis(diethylamino)-9-(o-chloroanilino)xantylbenzoic acid lactam), 3-diethylamino-6-methyl-7-(m-trichloromethylanilino)
Fluoran, 3-diethylamino-7-(0-chloroanilino)fluoran, 3-dibutylamino-7-(0-chloroanilino)fluoran, 3-N-methyl-N-amylamino-6-methyl-7-
Anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N- diethylamino)-5-methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylospirane, 6'-bromo-3'-methoxy-benzoindolino-pyrillospirane, 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'-dimethylaminophenyl)-3-(2'-methoxy-5'-methylphenyl)phthalide,3-(2'-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5'
-methylphenyl)phthalide, 3-(N-ethyl-N-i-amyl)amino-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-tetrahydrofurfuryl)amino-6-methyl -7-anilinofluorane, 3-(N-
Ethyl-N-ethoxypropyl)amino-6-methyl-
7-anilinofluorane, 3-(N-methyl-N-isopropyl)amino-6-methyl-7-anilinofluorane, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-p-chlorophenyl) ) methylaminofluorane, 3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-pt-luidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(p-0-butylanilino)fluoran.

3-(N-benzyl-N-cyclohexylamino)-5
, 6-penzo 7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-methyl-7-mesitidino 4
',5'-benzofluorane etc.

Further, as the color developer used in the present invention, various electron-accepting substances that react with the leuco dye and develop color when heated are used, and specific examples thereof include phenol as shown below. Examples include acidic substances, organic or inorganic acidic substances, or their esters and salts.

gallic acid, salicylic acid, 3-isopropylsalicylic acid,
3-cyclohexylsalicylic acid, 3,5-di-tert
-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, 4,4'-isopropylidene diphenol, 4,4'-isopropylidene bis(2-chlorophenol), 4,4'-isopropylidene bis( 2,6-dibromophenol), 4,4'-isopropylidene bis(2,6-dichlorophenol).

4.4'-isopropylidene bis(2-methylphenol), 4,4'-isopropylidene bis(2,6-dimethylphenol), 4,4'-isopropylidene bis(
2-tert-butylphenol), 4.4'-5
ee-butylidene diphenol, 4,4'-cyclohexylidene bisphenol, 4,4'-cyclohexylidene bis(2-methylphenol), 4-tert-butylphenol, 4-phenylphenol, 4-hydroxydiphenoxide, α -naphthol, β-naphthol, 3,5-xylenol, thymol, methyl-4-hydroxybenzoate, 4-hydroxyacetophenone,
Novolac type phenolic resin, 2,2'-thiobis(4
, 6-dichlorophenol), catechol, resorcinol, hydroquinone, pyrogallol, phloroglycine, phloroglycin carboxylic acid, 4 tert-octylcatechol, 2,2'-methylenebis(4-chlorophenol), 2,2'-methylenebis(4 -methyl-6-te
rt-butylphenol), 2,2'-dihydroxydiphenyl, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate, benzyl p-hydroxybenzoate, p-chlor p-hydroxybenzoate Benzyl, p-hydroxybenzoic acid-o-chlorobenzyl, p-hydroxybenzoic acid-p
-Methylbenzyl, n-octyl p-hydroxybenzoate, benzoic acid, zinc salicylate, l-hydroxy-2
-naphthoic acid, 2-hydroxy-6-naphthoic acid, 2-
Zinc hydroxy-6-naphthoate, 4-hydroxydiphenylsulfone, 4-hydroxy-4'-chlorodiphenylsulfone, bis(4-hydroxyphenyl)sulfide, 2-hydroxy-pt-ruylic acid, 3,5-di Zinc tert-butylsalicylate, 3,5-di-te
rt-tin butylsalicylate, tartaric acid, oxalic acid, maleic acid, citric acid, succinic acid, stearic acid, 4-hydroxyphthalic acid, boric acid, thiourea derivatives, 4-hydroxythiophenol derivatives, bis(4-hydroxyphenyl) Acetic acid, methyl bis(4-hydroxyphenyl)acetate, ethyl bis(4-hydroxyphenyl)acetate, bis(
4-Hydroxyphenyl) n-propyl acetate, bis(4
-hydroxyphenyl)n-butyl acetate, bis(4-hydroxyphenyl)phenyl acetate, bis(4-hydroxyphenyl)benzyl acetate, bis(4-hydroxyphenyl)phenethyl acetate, bis(3-methyl-4-hydroxyphenyl) Acetic acid, bis(3-methyl-4-hydroxyphenyl)methyl acetate, bis(3-methyl-4-hydroxyphenyl)ethyl acetate, bis(3-methyl-4-
hydroxyphenyl) n-propyl acetate, 1,7-bis(4-hydroxyphenylthio)3,5-dioxahebutane, 1,5-di(4-hydroxyphenylthio)-3
-oxapentane, dimethyl 4-hydroxyphthalate,
4-hydroxy-4'-methoxydiphenyl sulfone,
4-hydroxy-4'-ethoxydiphenyl sulfone,
4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-n-propoxydiphenylsulfone, 4-hydroxy-4'-n-butoxydiphenylsulfone, 4-hydroxy-4'-isobutoxydiphenylsulfone , 4-hydroxy-4'-5ec-
Butoxydiphenylsulfone, 4-hydroxy-4'-
terbutoxydiphenylsulfone, 4-hydroxy-
4'-Benzyloxydiphenylsulfone, 4-hydroxy-4'-phenoxydiphenylsulfone, 4-hydroxy-4'-(m-methylbenzyloxy)diphenylsulfone, 4-hydroxy-4'-(p-methylbenzyloxy) Roxy) diphenylsulfone, 4-hydroxy-4'-
(o-methylbenzyloxy)diphenylsulfone, 4-
Hydroxy-4'-(p-chlorobenzyloxy)diphenylsulfone, etc.

In the present invention, the ratio of the leuco dye and developer used in the thermosensitive coloring layer is 0.1 to 10 parts by weight, preferably 1 to 4 parts by weight, of the developer to 1 part by weight of leuco dye. be.

In the present invention, in order to bind and support the leuco dye and color developer on the support, various commonly used binders can be used as appropriate. Examples include those similar to those exemplified.

In addition, in the present invention, in addition to the leuco dye and color developer, if necessary, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, thermofusible substances ( or lubricant), etc. can be used in combination. In this case, fillers include, for example, calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, talc, and surface-treated inorganic fine powders such as calcium and silica. , urea-formalin resin, styrene/methacrylic acid copolymer, polystyrene resin, and other organic fine powders. Examples of thermofusible substances include higher fatty acids or their esters, amides, or metal salts. In addition, various waxes, condensates of aromatic carboxylic acids and amines, phenyl benzoate, higher linear glycols, dialkyl 3,4-epoxy-hexahydrophthalates, higher ketones, and other thermofusible materials. Examples include organic compounds having a melting point of about 50 to 200°C.

In the heat-sensitive recording material of the present invention, a protective layer may be provided on the heat-sensitive coloring layer for the purpose of improving the matching property with a thermal head or the like and further enhancing the storage stability of recorded images. In this case, the above-mentioned fillers, binders, surfactants, thermofusible substances, etc. can be used as components constituting the protective layer.

〔effect〕

The heat-sensitive recording material of the present invention has a back coat layer containing SnO2 and quaternary ammonium salt on the back surface of the support, so that it can prevent paper jams and jams in a wide range of environments during thermal printing and paper ejection. It does not cause matching troubles such as

〔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 (f).

Example 1 [A] Liquid 10% aqueous solution of polyvinyl alcohol 16 parts water
64 parts CB] Liquid P-benzyl oxybenzoate 10 parts Calcium carbonate 10 parts 10% aqueous solution of polyvinyl alcohol 16 parts Water
54 parts Each of the mixtures having the above composition was mixed with 2 parts in a sand grinder.
The mixture was pulverized and dispersed for ~4 hours to prepare liquid (A) and liquid [13].

Next, the liquid (A) and the liquid [B] were mixed and stirred at a weight ratio of 1:4 to obtain a heat-sensitive coating liquid (C).

Further, a mixture consisting of the following formulation was dispersed using a sand mill to obtain a protective layer coating liquid [0].

CD) Liquid silica 5 parts 10% aqueous solution of polyvinyl alcohol 50 parts Zinc stearate 5 parts Water
40 parts Next, a back coat liquid (E) having the following formulation was prepared.

[E) Liquid SnO2 dispersion 5 parts 10% aqueous solution of polyvinyl alcohol 50 parts water
5
0 part basis weight 50g/rl commercially available 2-quality paper with heat-sensitive coating liquid [
C) was coated and dried so that the dry weight was 3 g/m', and on top of that, the protective layer coating solution CD) was coated and dried so that the dry weight was 3 g/m'. A paper coated with a protective layer was obtained. Next, the back coat liquid (E) was applied to the back side of the paper coated with the protective layer so that the coating amount after drying was Ig/m. The heat-sensitive recording material of the present invention was obtained by calendering.

Example 2 Back coat liquid [E] was converted into back coat liquid CF having the following composition.
) The heat-sensitive recording material of the present invention was obtained in the same manner as in Example 1, except that .

[F] Liquid SnO2 dispersion 5 parts 10% aqueous solution of polyvinyl alcohol 50 parts water
50
Part Comparative Example 1 Apply liquid (E) to Barafuko-1 by applying bank coating liquid (
A comparative heat-sensitive recording material was obtained in the same manner as in Example 1 except that G) was used instead.

[G] Liquid zinc stearate 10 parts 10% aqueous solution of polyvinyl alcohol 50 parts water
50 parts Comparative Example 2 Transfer back coat liquid (E) to Barafco-1 having the following composition [
A heat-sensitive recording material for comparison was obtained in the same manner as in Example 1, except that the material was replaced with the old one.

[1-I] Liquid calcium carbonate 10 parts 10% aqueous solution of polyvinyl alcohol 50 parts water
5
0 parts The surface resistance of each of the heat-sensitive recording materials was measured and a paper jam test was conducted. The results are shown in Table-1.

Note) (i) Surface resistance was measured using a resistance meter manufactured by YHP.

(ji) For the FAX paper jam test, ■Fax 120 manufactured by Ricoh was used.

(iii) Ticket vending machine The paper jam test used an SK type ticket vending machine manufactured by Shinko Electric.

Table 1 Note) O...No practical problem ×...Practical problem It can be seen that there are no matching problems such as paper jams or jams when feeding and discharging paper, and that the matching performance is improved.

Claims (1)

[Claims] (1) In a heat-sensitive recording material comprising a heat-sensitive coloring layer on a support and, if necessary, a protective layer on the heat-sensitive coloring layer, a back coat containing SnO_2 and a quaternary ammonium salt on the back side of the support. A heat-sensitive recording material characterized by having a layer.