JPS63162283A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a high-printing quality thermal recording material having good dot-reproducibility and no possibility of jamming, by a method wherein a compound having either sulfone group or ammonium group is contained in at least one in either of respective layers or a supporting substrate. CONSTITUTION:In a thermal recording material wherein a thermal color-forming layer is provided on a water-resistant layer, which is mainly composed of a polymer and formed on a paper substrate, a compound having sulfone group or ammonium group is contained in at least one in either of the respective layers or a supporting substrate. As the polymer to be used for the water-resistant layer, a water-insoluble polymer or a water-soluble polymer combined with a crosslinking agent is preferably used with a coating weight of 1g/m<2> or more. The water-resistant layer of aqueous or solvent series is desirably formed by being coated on a paper substrate, or alternatively it can be formed by laminating a thermoplastic polymer on the paper substrate. The production of the thermal recording material is performed as follows: in a series using and electron donative dye-precursor and an electron acceptive compound, a color former and a color developer are separately dispersed to several microns or below and mixed to obtain a thermal coating liquid. The color former and the color developer are generally dispersed with a water-soluble high-molecular water solution, and a sensitizer is added in dispersed form, as necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material intended for high image quality and high sensitivity.

(Prior art) Various heat-sensitive recording materials have been known for a long time.In particular, heat-sensitive recording materials using electron-donating dye precursors and electron-accepting compounds are disclosed in Japanese Patent Publications Nos. 45-14039 and 43 -4160 etc.

In addition, heat-sensitive recording materials using diazo compounds were published in Japanese Patent Publication No. 5
No. 9-190886, etc.

In recent years, these thermal recording systems have been applied to a wide variety of fields such as facsimiles, printers, and labels, and their needs are expanding. Along with this, characteristics that were not so required in the past have come to be required of thermosensitive recording. One of these is the reproducibility of printed dots. -Finally, thermal recording paper is
Printing is performed by heating with a micro heating element of about 100 μm x 200 μm called a thermal head, and at this time, being able to faithfully reproduce the shape of the micro heating element as a coloring body is a major factor in achieving high print quality. I've come to understand that. This is called print dot reproducibility.

In order to improve the reproducibility of printed dots, it is effective to coat a heat-sensitive coloring layer on a highly flat support such as laminated paper. When the device prints, it comes into contact with the plastic conveyance system such as stockers, rollers, and trays in the device and becomes charged, causing sheets to stick to each other or sheets and the conveyance system due to electrostatic force, causing so-called "jamming." The problem was that it was easy.

(Object of the Invention) An object of the present invention is to provide a heat-sensitive recording material with good dot reproducibility and high print quality that does not cause jamming.

(Structure of the Invention) The object of the present invention is to provide a heat-sensitive recording material in which a heat-sensitive coloring layer is provided on a water-resistant layer of a paper support having a water-resistant layer mainly composed of a polymer, in which each layer is coated with a compound having a sulfone group or an ammonium group. Or achieved by a thermosensitive material, characterized in that it is contained in at least one of the supports.

The polymer used for the water-resistant layer is preferably a water-insoluble polymer or a water-soluble polymer combined with a crosslinking agent, and the coating amount is l g
# or more is preferable. The water-resistant layer is preferably provided by coating the paper support with an aqueous or solvent-based coating. Alternatively, a water-resistant layer may be provided by laminating a thermoplastic polymer onto a paper support. In the present invention, the water-insoluble polymer refers to synthetic rubber latex or synthetic resin emulsion, and specifically, styrene-butadiene rubber latex, 7-crylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, Examples include vinyl acetate emulsion.

Examples of water-soluble polymers include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, and isobutylene. -Maleic anhydride copolymer hydrolyzate, polyvinyl alcohol,
Examples include carboxy-modified polyvinyl alcohol and polyacrylamide. As a crosslinking agent, N-methylol urea, N-methylol melamine, urea-formalin,
Water-soluble initial condensation resins such as henzoguanamine-formalin and acetoguanamine-formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax, polyacrylic acid, methyl-vinyl ether-maleic acid copolymers , isobutylene-maleic anhydride copolymer, and the like. It is preferable to use these crosslinking agents in an amount of 1 to 50% by weight of the water-soluble polymer.

The compounds having a sulfone group or ammonium group used in the present invention are preferably those represented by the following general formulas (1) to (■).

R,0(CH2)l SO:1M
(1”) So→C11z-Ch
(TV) Rl 20 aryl group -R7-1-R, □-1-R,, - represents an alkylene group having 1 to 20 carbon atoms), M represents an alkali metal or ammonium group, and A represents a halogen group. In the atoms, l represents 1 to 20 and mq represents 50 to 5000. ) At least one kind of compounds represented by these general formulas (1) to (■) is used.

These compounds are usually prepared on a support 1. /0.0001 per
-1g, preferably 0.05-0.2g.

The heat-sensitive recording material of the present invention basically consists of a support and a heat-sensitive coloring layer provided thereon. A protective layer, undercoat layer, and bank layer may be provided in some cases,
-S The compounds represented by formulas (1) to (■) may be added to any layer.

Specific examples represented by general formulas (1) to (■) include +(Jl, -CH→1-CI.

+CH, -C→]- CIIzO5OJa -←CHz Cll→]- C00CIItCIIzSOJa Cl1zSOJ (Note: For the above specific compounds, n = 50 to
It is 5000. ), etc.

Next, a method for manufacturing a typical heat-sensitive recording material of the present invention will be described. -For example, in a system using an electron-donating dye precursor (hereinafter referred to as a color former) and an electron-accepting compound (hereinafter referred to as a color developer),
Angry passion can be obtained by separately dispersing the color forming agent and the color developer to a size of several microns or less using a ball mill, sand mill, etc. and mixing them.

The color forming agent and developer are dispersed together with an aqueous solution of a water-soluble polymer such as polyvinyl alcohol, and if necessary, a sensitizer can also be dispersed and added. The sensitizer may be added to either or both of the color former and the color developer and may be dispersed simultaneously.

Examples of the coloring agent used in the present invention include triarylmethane compounds, diphenylmethane compounds, xanthine compounds, thiazine compounds, and spiropyran compounds. Some examples of these include 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (i.e. crystal violet lactone), 3
．． 3-bis(p-dimethylaminophenyl)phthalide,
3-(p-dimethylaminophenyl)-3-(1゜3-
dimethylindol-3-yl)phthalide, 3-(p-
Dimethylaminophenyl)-3-(2-methylindol-3-yl)phthalide, etc., and diphenylmethane compounds include 4.4'-bis-dimethylaminobenzhydrin henzyl ether, N-halophenyl-leucoolae, etc. Xanthine-based compounds include rhodamine-B-anilinolactam, rhodamine (p-nitroanilino)lactam, and rhodamine B (p-nitroanilino)lactam.
chloroanilino)lactam, 2-dibenzylamino-6
-diethylaminofluorane, 2-anilino-6-diethylaminofluorane, 2-anilino-3-methyl-6
-diethylaminofluorane, 2-anilino-3-methyl-6-N-cyclohexyl-N-methylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N
-isoamylaminofluorane, 2-0-chloroanilino-6-diethylaminofluorane, 2-m=chloroanilino-6-diethylaminofluorane, 2-(3,4
-dichloroanilino)-6-diethylaminofluorane, 2-octylamino-6-diethylaminofluorane, 2-dihexylamino-6-diethylaminofluorane, 2-m-trichloromethylanilino-6-diethylaminofluorane, 2 -butylamino-3-chloro-6
-diethylaminofluorane, 2-ethoxyethylamino-3-chloro-6-diethylaminofluorane, 2-
Anilino-3-chloro-6-diethylaminofluoran, 2-diphenylamino-6-diethylaminofluoran, 2-anilino-3-methyl-6-siphenylaminofluoran, 2-anilino-3-methyl-5-chloro −
6-diethylaminofluorane, 2-anilino-3-methyl-6-dinithylamino-7-methylfluorane, 2
-anilino-3-methoxy-6-sibutylaminofluorane, 2-0-chloroanilino-6-sibutylaminofluorane, 2-p-chloroanilino-3-ethoxy-6
-diethylaminofluorane, 2-phenyl-6-diethylaminofluorane, 2-o-chloroanilino-5-
p-Butylanilinofluorane, 2-anilino-3-pentadecyl-6-diethylaminofluorane, 2-anilino-3-ethyl-6-sibutylaminofluorane, 2
-anilino-3-ethyl-6-N-ethyl-N-isoacylaminofluorane, 2-anilino-3-methyl-6
-N-ethyl-Nr-methoxypropylaminofluorane, 2-anilino-3-phenyl-6-diethylaminofluorane, 2-diethylamino-3-phenyl-6-
There are dinitylaminofluorane, 2-anilino-3-methyl-6-N-isoamyl-N-ethylaminofluorane, etc. Thiazine compounds include benzoylleucomethylene blue, p-nitrobenzylleucomethylene blue, etc. Examples of the system compounds include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3゜3'-cyclorosespiro-dinaphthopyran, 3-benzylspiro-dinaphthopyran, and 3-methyl-spiro-dinaphthopyran.
naphtho-(3-methoxy-benzo)-spiropyran, 3
-propyl-spiro-dibenzobilane and the like. These are used alone or in combination to adjust hue or improve image preservation.

The color developer used in the present invention is 2,2-bis(4'
-Hydroxyphenyl)propane (bisphenol A)
, 2.2-bis(4-hydroxyphenyl)pentane,
2,2-bis(4'-hydroxy-3',5'-dichlorophenyl)propane, l,l-bis(4'-hydroxyphenyl)cyclohexane, 2,2-bis(4'-hydroxyphenyl)hexane, 1 ．． l-bis(4'-hydroxyphenyl)propane, 1,1-bis(4'-hydroxyphenyl)butane, 1,1-bis(4'-hydroxyphenyl)pentane, 1,1-bis(4'-hydroxy phenyl)hexane, 1,1-bis(4'-hydroxyphenyl)heptano, 1,1-bis(4'-hydroxyphenyl)octane, 1,1-bis(4°-hydroxyphenyl)-2-methyl-pentane , 1,1-bis(4-hydroxyphenyl)-2-ethyl-hexane, bisphenols of 1,1-bis(4'-hydroxyphenyl)dodecane, 3.5-di-α-methylbenzylsalicylic acid, 3. 5-
Salicylic acids such as di-tert-butylsalicylic acid, 3-α,α-dimethylbenzylsalicylic acid or their polyvalent metal salts (zinc and aluminum are particularly preferred), p-hydroxybenzoic acid benzyl ester, p-hydroxybenzoic acid-2 -oxybenzoic acid esters such as ethylhexyl ester, p-phenylphenol, 3,
Examples include phenols such as 5-diphenylphenol and cumylphenol, with bisphenols being particularly preferred.

Examples of the sensitizer include organic compounds having a melting point of 70°C or more and 150°C or less. Specific examples of the compound include compounds represented by the following general formulas (1) to (IV).

In the formula, RI'= R4 represents a phenyl group, a hensyl group, and a lower alkyl, halogen, hydroxy, or alkoxy substituted product thereof, R1 and R6 each represent an alkyl group having 12 to 24 carbon atoms, and R1
represents hydrogen or phenyl group.

In addition, when the phenyl group or benzyl group represented by R2 to R4 in (maximum N) to (III) is substituted with a lower alkyl group, the number of carbon atoms is 1 to 8, preferably 1 to 3. be. When substituted with halogen, preferred is chlorine or fluorine.

In the formula, R8 represents a divalent group, preferably an alkylene group, an alkylene group having an ether bond, an alkylene group having a carbonyl group, an alkylene group having a halogen atom, an alkylene group having an unsaturated bond, and more preferably an alkylene group. group, an alkylene group with an ether bond. A,
B represents 0 or S, and ASBs may be the same or different. In addition, xSy, z, x', Y', and Z' may be the same or different, and are a hydrogen atom, an alkyl group, a lower alkoxy group, a lower aralkyl group, a halogen atom, an alkyloxycarbonyl group, an aralkyloxycarbonyl group. shows.

Specifically, benzyl p-hensyloxybenzoate, β
- naphthylhensyl ether, β-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, β-naphthol (p-10 lohenzyl) ether, β-naphthol (p-methylhensyl) ether,
α-Naphthylhensyl ether, 1.4-butanediol-p-methylphenyl ether, 1.4-butanediol-p-methylphenyl ether, 1.4-butanediol-p-isopropylphenyl ether, 1.4-
butanediol-pt-octylphenyl ether,
2-phenoxy-1-p-tolyl-oxy-ethane, 1
-phenoxy-2-(4-ethylphenoxy)ethane,
Examples include 1-phenoxy-2-(4-chlorophenoxy)ethane, 1°4-butanedioldiphenyl ether, (4°4'-methoxyphenylthio)ethane, and the like.

The thermofusible substances may be used alone or in combination.

Examples of binders include water-soluble polymers and water-insoluble binders, and the binders may be used alone or in combination of two or more.

Examples of water-soluble polymers include methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate , isobutylene-maleic anhydride copolymer hydrolyzate, polyvinyl alcohol, carboxy'12 polyvinyl alcohol, polyacrylamide, and the like.

As a water-insoluble binder, synthetic rubber latte is used.

Generally, wax or synthetic resin emulsion is used.
Examples include styrene-butadiene rubber latex, agrilonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion.

All general organic or inorganic pigments can be used as pigments, but those with an oil absorption of 40 cc/100 g or more as defined by JIS-K5101 are particularly preferred, and specific examples include calcium carbonate, barium sulfate, and oxide. Examples include titanium, talc, waxite, kaolin, calcined kaolin, aluminum hydroxide, amorphous silica, urea-formalin resin powder, polyethylene resin powder, and the like.

Examples of the wax include polyethylene, wax, carnauba wax, paraffin wax, microcrystalline wax, candelia wax, montan wax, fatty acid amide, and the like. These have a melting point of 4
0°C or higher and 120°C or lower, preferably 50°C or higher, 100°C
℃ or less is used.

As the metal soap, higher fatty acid metal salts are used, such as zinc stearate, calcium stearate, aluminum stearate, and the like.

Antioxidants, ultraviolet absorbers, image storage improvers, and the like can be added as necessary.

Examples of image storage improvers include phenols or derivatives thereof in which at least one of the 2nd or 6th positions is substituted with an alkyl group, and among these, one or more of the 2nd or 6th positions is substituted with a branched alkyl group. phenol or its derivatives are preferred. Further, those having a plurality of phenol groups in the molecule are preferred, and those having 2 to 3 phenol groups are particularly preferred.

(Examples of the Invention) Examples are shown below, but the present invention is not limited thereto. Each heat-sensitive recording material contains 1 piece of polyethylene on high-quality paper.
3 g/rrr A heat-sensitive coating liquid was applied to the laminated support with a wire bar so that the dry coating amount was 6 g/m, and 5
After drying in an oven at 0°C, an aqueous solution of each compound shown in Table 1 was applied to the back side with a wire bar so that the dry weight was 0.1 g/m, and dried in an oven at 50°C. Ta.

(8-yen type of 7 nights of angry coating) 2-anilino-3-methyl-N-methyl- as a coloring agent
N-cyclohexylaminofluorane, bisphenol A as a color developer, β-naphthylbenzyl ether as a stimulant, 20 g each, and 100 g of a 5% polyvinyl alcohol solution were dispersed in a ball mill overnight to give a volume average particle size of 3 μm or less. . The pigment is calcium carbonate (L
Inibur70 (Shiraishi Kogyo), 80g of sodium hexametaphosphate 0.5%? It was used after being dispersed with 160 g of the liquid using a homogenizer. 2-anilino-3-methyl-6-N-
Methyl-N-cyclohexylaminofluorane dispersion 5
g, bisphenol A molecule l & ? (110 g of β-naphthylbenzyl ether dispersion, 15 g of calcium carbonate dispersion were mixed, and 3 g of 21% zinc stearate emulsion was further added.

Regarding the samples created in each of the above examples and comparative examples, facsimiles of type A A-1 and model A-2, which are particularly susceptible to jamming among commercially available facsimiles, were used.
A test pattern in which 25% of the screen was black was printed on 100 sheets in succession to determine how many sheets jammed. Printing was performed at a temperature of 15° C. and relative humidity, and if jamming occurred, the paper was removed and the printing test was continued. As a result, the results shown in Table 1 were obtained.

Claims (1)

[Claims] In a heat-sensitive recording material in which a heat-sensitive coloring layer is provided on a water-resistant layer of a paper support that has a water-resistant layer mainly composed of a polymer, a compound having a sulfone group or an ammonium group is added to at least one of each layer or the support. A heat-sensitive recording material characterized by containing: