JP2000280628A - Recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a recording material of superior resistance to water, resistance to chemicals, traveling properties and manufacture adaptability. SOLUTION: A heat-sensitive recording material is provided with a colored layer containing at least a substantially colorless coloring component A and a substantially colorless coloring component B to be colored by the reaction with the coloring component A and formed on a substrate, and a polyvinyl alcohol of 55-90 molar % isotacticity based on the dyad convention and 85 molar % or more saponification degree is contained in the coloring layer. A protective layer is formed on the colored layer of the recording material, and a polyvinyl alcohol of 55-90 molar % isotacticity based on the dyad convention and 85 molar % or more saponification degree is contained at least in one of the coloring layer or the protective layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, and more particularly, to a recording material having a color-forming layer or a recording material having a color-forming layer and a protective layer, which is excellent in water resistance, chemical resistance, running property and production suitability. Related to recording materials.

[0002]

2. Description of the Related Art Recording materials using an electron-donating colorless dye and an electron-accepting compound as color-forming components are already well known as pressure-sensitive paper, heat-sensitive paper, photosensitive pressure-sensitive paper, energized heat-sensitive recording paper, heat-sensitive transfer paper and the like. ing. For example, British Patent No. 2,14
No. 4,449, U.S. Pat. Nos. 4,480,052, 4,436,920, JP-B-60-23992, JP-A-57-179636, and JP-A-60-123556.
No. 60-123557. For example, with respect to heat-sensitive recording, heat-sensitive recording materials using an electron-donating dye precursor and an electron-accepting compound are disclosed in JP-B-45-14039 and JP-B-43-4160. A heat-sensitive recording material using a diazo compound is disclosed in JP-A-59-1908.
No. 86 and the like.

In recent years, these recording systems have been applied to various fields such as facsimile machines, printers, labels, terminals for meter reading, medical image output, and prepaid cards, and the needs are expanding. Along with this, the use of the above materials in homes and outdoors is increasing, and it is recorded from the market from a practical viewpoint, such as handling with wet hands, adhesion of the painted surface due to rain or snow and adhesion, peeling, etc. The demand for water resistance of materials is increasing.

On the other hand, such a recording material is generally inferior in water resistance, chemical resistance, plasticizer resistance, and the like. For example, when a color image contacts a plasticizer contained in water, oil, plastic, or the like, The image density may be significantly reduced. Further, since the surface properties are not uniform, sticking may occur and image quality may be degraded.

To simplify such a problem, for example,
In JP-A-59-106995 and the like, a protective layer mainly composed of an acetoacetylated polyvinyl alcohol-based resin and / or a polyvinyl alcohol-based resin having at least acrylonitrile as a copolymer component is provided on a heat-sensitive recording layer. A technique for improving the water resistance of a heat-sensitive recording material has been proposed.

[0006] However, the coating liquid containing the water-soluble resin has a problem that the coating liquid cannot be applied stably because the viscosity is rapidly increased. In addition, since the water-soluble resin gels in the solution, there is a disadvantage that the life of the coating solution is short. Furthermore, when a protective layer or the like is actually prepared using these coating solutions, a part of the binder in the coating solution may be insolubilized, and as a result, the surface of the protective layer or the like may have irregularities, and the heat-sensitive recording material The surface properties may deteriorate. Deterioration of the surface properties causes a surface defect due to sticking of a thermal head or the like at the time of printing, which leads to deterioration of image quality,
As a result, the performance was not sufficient.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording material which is excellent in water resistance, chemical resistance, running properties and production suitability.

[0008]

SUMMARY OF THE INVENTION An object of the present invention described above is to provide at least a substantially colorless color-forming component A on a support and a substantially colorless color-forming component B which reacts with the color-forming component A to form a color. Wherein the coloring layer contains a polyvinyl alcohol resin having an isotacticity of 55 to 90 mol% by diat display and a saponification degree of 85 mol% or more. Achieved by the recording material. Further, the above-mentioned object of the present invention is to provide a color-forming layer containing at least a substantially colorless color-forming component A and a substantially colorless color-forming component B which reacts with the color-forming component A to form a color on a support, In a recording material in which a protective layer mainly composed of a pigment and a binder is provided on the color-forming layer, at least one of the color-forming layer and the protective layer has an isotacticity of 55 to 90 mol% by diat display and saponification. And a polyvinyl alcohol-based resin having a degree of 85 mol% or more.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in more detail. The recording material of the present invention,
(1) At least a substantially colorless color-forming component A on a support
A recording material having a color-forming layer containing: and a substantially colorless color-forming component B that forms a color by reacting with the color-forming component A; (2)
At least a substantially colorless color-forming component A and a substantially colorless color-forming component B that reacts with the color-forming component A to form a color on a support
And a recording material provided with a protective layer containing a pigment and a binder as main components on the color forming layer.

In the case of the recording material of (1), the isotacticity by diat display in the color forming layer is from 55 mol% to 9 mol%.
It contains a polyvinyl alcohol-based resin having 0 mol% and a saponification degree of 85 mol% or more. In the case of the recording material of (2), at least one of the coloring layer and the protective layer contains a polyvinyl alcohol resin having an isotacticity of 55 to 90 mol% by diat display and a saponification degree of 85 mol% or more. You. Therefore, the isotacticity by diat display in the coloring layer or the protective layer is 55 mol%.
A polyvinyl alcohol-based resin having a saponification degree of 85 mol% or more, and a coloration layer and a protective layer each having an isotacticity of 55 mol% to 90 mol% by diat display. May contain a polyvinyl alcohol resin of 85 mol% or more.

The isotacticity (hereinafter, also referred to as isotype) contained in the recording material of the present invention is a triatomic property determined by measuring an NMR spectrum of a hydroxyl proton of polyvinyl alcohol dissolved in deuterated dimethyl sulfoxide. Assuming that tee, isotacticity (I), heterotacticity (H), and syndiotacticity (S), the diad tacticity calculated by i = I + H / 2, s = S + H / 2, that is, isotacticity This is represented by the situation (i). s represents syndiotacticity. This iso- (hereinafter also referred to as i-) polyvinyl alcohol is obtained by debenzylating an ionic polymer of benzyl vinyl ether with HBr. In addition, it can be similarly obtained from an ionic polymer of t-butyl vinyl ether (in toluene) and an ionic polymer of vinyl tributylsilyl ether (in nitroethane).

In order to have sufficient water resistance and the like in the i-polyvinyl alcohol, the isotacticity (i) is from 55 mol% to 90 mol% in diat representation, preferably from 55.5 mol% to It is 85 mol%, more preferably 55.8 mol% to 80 mol%. When the i-property is less than 55 mol%, sufficient water resistance and chemical resistance cannot be obtained, and when the i-property is too large, the solubility in water is undesirably reduced. However, in that case, it can be adjusted by introducing a water-soluble group as long as the i-property is not significantly reduced.
The degree of polymerization of i-polyvinyl alcohol is 300 to 40.
00 is preferable, and from the viewpoints of coatability, water resistance, etc., 50
0 to 2000 is desirable. The degree of saponification of the i-polyvinyl alcohol is preferably at least 85 mol%, more preferably at least 98 mol%. If the saponification degree is less than 85 mol%, sufficient water resistance and chemical resistance cannot be obtained. Also, the distribution of i-OH group is more localized than random,
It is preferable for crosslinkability with dialdehyde and the like and gelation with boric acid and the like. Therefore, the coating liquid has good stability and solubility, and when boric acid or the like diffuses from the lower layer, it is easily gelled, and layer mixing does not occur, so that printing trouble hardly occurs.

[0013] These i-polyvinyl alcohols are
It may be further modified with other functional groups within a range that does not adversely affect its stereoregularity, performance and coating liquid stability. Specific examples include functional groups such as a carboxyl group, an ethylene group, a terminal alkyl group, an amino group, a sulfonic acid group, a terminal thiol group, a silanol group, and an amide group. High i-
A carboxyl group-modified, amino group-modified sulfonic acid group or the like is effective for imparting the solubility of the hydrophilic polyvinyl alcohol.

In the protective layer, other binder components may be used in combination with the i-polyvinyl alcohol, if necessary.
Carboxymethyl cellulose, hydroxyethyl cellulose, starch, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, isobutylene-maleic anhydride copolymer hydrolysis Products, polyvinyl alcohol, modified polyvinyl alcohol, polyacrylamide and the like. However, the combined use of a water-soluble polymer may cause a decrease in water resistance, and care must be taken regarding the amount and type of the combined use.

As the water-insoluble binder, a synthetic rubber latex or a synthetic resin emulsion is generally used, and examples thereof include styrene butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion. The amount of the binder used is 10 to 500% by weight, preferably 50% by weight, based on the pigment contained in the protective layer.
４００400% by weight.

In order to further improve the water resistance, it is effective to use a crosslinking agent and a catalyst for accelerating the reaction.
Specific examples of the crosslinking agent include an epoxy compound, a blocked isocyanate, a vinyl sulfone compound, an aldehyde compound, a methylol compound, boric acid, a carboxylic anhydride, a silane compound, a chelate compound, and a halide. Preferably, the pH can be adjusted to 6.0 to 7.5. As the catalyst, known catalysts such as acids and metal salts can be used.
Those that can be adjusted to 7.5 are preferred.

As the epoxy compound, those having two or more functions can be used. For example, dibromophenyl glycidyl ether, dibromoneopentyl glycol diglycidyl ether, emulsion of epoxy cresol novolak resin, modified bisphenol A type epoxy emulsion, diglycidyl adipate Esters, o-phthalic acid diglycidyl ester, hydroquinone diglycidyl ether, bisphenol S glycidyl ether, terephthalic acid diglycidyl ether, glycidyl phthalimide, propylene polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol (E ) 5 glycidyl ether, p-
Tertiary butyl phenyl glycidyl ether, lauryl alcohol (EO) 15 glycidyl ether, glycidyl ether of an alcohol mixture having 12 to 13 carbon atoms,
Glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene polyethylene glycol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether And polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl-tris (2-hydroxyethyl) isocyanurate and the like. Among these epoxy compounds, glycidyl ethers are particularly preferable. is there.

The epoxy compound effective for the present invention preferably has an epoxy equivalent of 70 to 1000 WPE. When the epoxy equivalent exceeds 1000 WPE, it becomes difficult to impart water resistance, which is not preferable.

The term "blocked isocyanate" refers to a compound obtained by masking the terminal isocyanate group of an isocyanate with a blocking agent. Blocked isocyanates include:
For example, (a) an isocyanate compound in which a block of a hydrophilic group comprising a carbamoyl sulfonate group (—NHCOSO ₃ ⁻ ) is formed at the terminal and an active isocyanate group is blocked, and (b) isopropylidene malonate is used. Blocking active isocyanate groups.
Examples of the blocked isocyanate include (c) a compound obtained by reacting HDI isocyanurate, isopropylidene malonate, and triethylamine, in which an active isocyanate group is blocked with a phenol. When such a blocked isocyanate is mixed with i-polyvinyl alcohol and heated, the i-polyvinyl alcohol is crosslinked and reformed, whereby the water resistance of the i-polyvinyl alcohol is achieved.

As the vinyl sulfone compound, those described in JP-A-53-57257, JP-A-53-41221, JP-B-49-13563, JP-B-47-24259, and the like can be used. It is.

Examples of the aldehyde compound include monoaldehydes such as formaldehyde and acetaldehyde, and polyvalent aldehydes such as glyoxal, glutaraldehyde and dialdehyde starch. Examples of the methylol compound include methylol melamine and dimethylol urea. In the case of i-polyvinyl alcohol, an aldehyde compound which easily reacts with an isotactic OH group is particularly suitable as a crosslinking agent.

The amount of the crosslinking agent used for the above-mentioned i-polyvinyl alcohol is
It is desirable to add 3 to 50 parts by weight of a crosslinking agent to 00 parts by weight. When the amount of the crosslinking agent is less than 3 parts by weight, the degree of crosslinking modification is low, and the water resistance and chemical resistance become insufficient. On the other hand, when the amount exceeds 50 parts by weight, the liquid stability decreases, and Absent.

As the pigment that can be used in the protective layer of the present invention, all general organic or inorganic pigments can be used.
Specifically, calcium carbonate, aluminum hydroxide, barium sulfate, titanium oxide, talc, limestone, kaolin, calcined kaolin, amorphous silica, urea formalin resin powder,
Examples include polyethylene resin powder and benzoguanamine resin powder. These are used alone or in combination of two or more.

The protective layer coating liquid of the present invention is obtained by mixing a dispersion of the above pigment, i-polyvinyl alcohol, a crosslinking agent, a catalyst and the like. Further, a release agent, a surfactant, a wax, a water repellent and the like may be added as necessary. The obtained protective layer coating liquid is applied onto the thermosensitive coloring layer using a bar coater, an air knife coater, a blade coater, a curtain coater or the like, and dried to obtain a protective layer of the present invention.
However, the protective layer may be applied simultaneously with the color-forming layer, or after the heat-sensitive color-forming layer is applied, the heat-sensitive color-forming layer may be dried once and then applied thereon. The dry coating amount of the protective layer is 0.
5 to 5 g / m ² is preferred, and more preferably 0.8 to 5 g / m ^2.
2 g / m ² . If the coating amount is large, the thermal sensitivity is remarkably reduced, and if the coating amount is too low, the water resistance cannot be maintained. After the application of the protective layer, a calendering treatment may be performed as necessary.

Next, the color-forming layer in the present invention contains at least a substantially colorless color-forming component A, and the color-forming component A reacts to form a substantially colorless color-forming component B. The color-forming component A and the color-forming component B used in the present invention are components that cause a color-forming reaction when they come into contact with each other, and examples of the combinations thereof include the following (A) to (W). .

(A) Combination of a photodegradable diazo compound and a coupler. (B) A combination of an electron-donating dye precursor and an electron-accepting compound. (C) A combination of an organic metal salt such as silver behenate and silver stearate with a reducing agent such as protocatechinic acid, spiroindane and hydroquinone. (D) A combination of a long-chain fatty acid salt such as ferric stearate and ferric myristate and a phenol such as tannic acid, gallic acid and ammonium salicylate.

(E) Organic acid heavy metal salts such as nickel, cobalt, lead, copper, iron, mercury and silver salts such as acetic acid, stearic acid and palmitic acid; and alkalis such as calcium sulfide, strontium sulfide and potassium sulfide. A combination with an earth metal sulfide or a combination of the organic acid heavy metal salt and an organic chelating agent such as s-diphenylcarbazide or diphenylcarbazone. (F) A combination of a heavy metal sulfate such as a sulfate such as silver, lead, mercury and sodium with a sulfur compound such as Na-tetrathionate, sodium thiosulfate and thiourea.

(G) A combination of a ferric fatty acid salt such as ferric stearate and an aromatic polyhydroxy compound such as 3,4-hydroxytetraphenylmethane. (H) A combination of an organic acid metal salt such as oxalate and mercury oxalate and an organic polyhydroxy compound such as polyhydroxy alcohol, glycerin and glycol. (Ii) A combination of a ferric fatty acid salt such as ferric pelargonic acid or ferric laurate, and a thiocesylcarbamide or isothiocesylcarbamide derivative.

(Nu) Lead salts of organic acids such as lead caproate, lead pelargonate and lead behenate, ethylene thiourea, N
-In combination with a thiourea derivative such as dodecylthiourea. (R) A combination of a heavy metal salt of a higher fatty acid such as ferric stearate and copper stearate with zinc dialkyldithiocarbamate. (Ii) Those that form an oxazine dye, such as a combination of resorcinol and a nitroso compound. (W) A combination of a formazan compound and a reducing agent and / or a metal salt.

Among these, in the present invention, (a)
A combination of a photodegradable diazo compound and a coupler, a combination of an electron-donating dye precursor and an electron-accepting compound (b),
The combination of the organic metal salt of (c) and the reducing agent is preferable, and the cases (a) and (b) are particularly preferable. The photodegradable diazo compound in the combination of the photodegradable diazo compound and the coupler is one that develops a desired hue by reacting with a developer called a coupling component described later, and has a specific wavelength before the reaction. It is a diazo compound that decomposes when exposed to light and no longer has a coloring ability even when a coupling component acts.

The hue in this color forming system is mainly determined by the diazo dye formed by the reaction between the diazo compound and the coupling component. Therefore, as is well known,
The color hue can be easily changed by changing the chemical structure of the diazo compound or the chemical structure of the coupling component, and almost any color hue can be obtained depending on the combination.

The photo-decomposable diazo compound in the present invention mainly refers to an aromatic diazo compound, and more specifically refers to an aromatic diazonium salt, a diazosulfonate compound, and a diazoamino compound. The diazonium salt has the general formula Ar
A compound represented by N ₂ ⁺ X ⁻ (wherein, Ar represents a substituted or unsubstituted aromatic moiety, N ₂ ⁺ represents a diazonium group, and X ⁻ represents an acid anion).

It is generally said that the photolysis wavelength of a diazonium salt is the absorption maximum wavelength. The maximum absorption wavelength of the diazonium salt is 200 nm depending on its chemical structure.
It is known that the wavelength varies from about 700 nm to about 700 nm [“Photodecomposition and chemical structure of photosensitive diazonium salt” by Takahiro Tsunoda and Ao Yamaoka Journal of the Photographic Society of Japan 29 (4) 197-2.
05 (1965)]. That is, when a diazonium salt is used as a photodecomposable compound, it is decomposed by light having a specific wavelength according to its chemical structure, or, when the chemical structure of the diazonium salt is changed, the same coupling component undergoes a coupling reaction. The hue of the dye also changes.

Many diazosulfonate compounds which can be used in the present invention are known and can be obtained by treating each diazonium salt with a sulfite.
The diazoamino compound that can be used in the present invention is obtained by coupling the diazo group with dicyandiamide, sarcosine, methyltaurine, N-ethylanthranic acid-5-sulfonic acid, monoethanolamine, jetanolamine, guanidine, or the like. Compound. Details of these diazo compounds are described in, for example, JP-A-2-136286.

As a light source for photolysis of a diazo compound,
Various light sources that emit light of a desired wavelength can be used. For example, various light sources such as various fluorescent lamps, xenon lamps, xenon flash lamps, mercury lamps of various pressures, photographic flashes, and strobes can be used. or,
In order to make the light fixing zone compact, the light source section and the exposure section may be separated using an optical fiber.

Coupling components that form a dye by coupling with the diazo compound used in the present invention include, for example, 2-hydroxy-3-naphthoic acid anilide, resorcinol, and JP-A-62-146678. Can be mentioned. Furthermore, an image of any color tone can be obtained by using two or more of these coupling components in combination. Therefore, the present invention is not limited to a single-color heat-sensitive recording material.

Since the coupling reaction between the diazo compound and the coupling component easily occurs in a basic atmosphere, a basic substance may be added to the recording layer. As the basic substance, a water-insoluble or water-insoluble basic substance or a substance that generates an alkali by heating is used. Examples thereof include inorganic and organic ammonium salts, organic amines, amides, ureas and thioureas and their derivatives, thiazoles, viroles, pyrimidines, piperazines, guanidines, indoles, imidazoles, imidazolines, triazoles. , Morpholines, piperidines,
Examples include nitrogen-containing compounds such as amidines, pharmaazines, and pyridines. Specific examples thereof are described in, for example, JP-A-61-291183. Incidentally, two or more basic substances may be used in combination.

The electron-donating dye precursor in the combination of the electron-donating dye precursor and the electron-accepting compound is not particularly limited, but has a property of forming a color by donating electrons or receiving a proton such as an acid. Which is generally colorless and has a partial skeleton such as lactone, lactam, sultone, spiropyran, ester, amide, etc., and the partial skeleton of these ring-opened upon contact with an electron accepting compound as a color developer. Alternatively, a compound that cleaves is used.

Specifically, crystal violet lactone, benzoyl leucomethylene blue, malachite green lactone, rhodamine B lactam, 1,3,3-
And trimethyl-6'-ethyl-8'-butoxyindolinobenzospiropyran. As the electron-accepting compound for these coloring agents, acidic substances such as phenol compounds, organic phosphoric acid compounds, and fatty acid carboxylic acid compounds are used.

Specific examples of the phenol compound include p-
(Dodecylthio) phenol, p- (tetradecylthio) phenol, p- (hexadecylthio) phenol, p- (octadecylthio) phenol, p- (eicosylthio) phenol, p- (docosylthio) phenol, p- (tetracosylthio) phenol Phenol, p- (dodecyloxy) phenol, p- (tetradecyloxy) phenol, p- (hexadecyloxy) phenol, p- (octadecyloxy) phenol, p- (eicosyloxy) phenol, p- (docosyloxy)
Phenol, p- (tetracosyloxy) phenol,
p-dodecylcarbamoylphenol, p-tetradecylcarbamoylphenol, p-hexadecylcarbamoylphenol, p-octadecylcarbamoylphenol, p-eicosylcarbamoylphenol, p-docosylcarbamoylfail, p-tetracosylcarbamoylphenol, hexagallate Decyl ester, octadecyl gallate, eicosyl gallate, docosyl gallate, tetracosyl gallate and the like.

Specific examples of the organic phosphoric acid compound include dodecylphosphonic acid, tetradodecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, eicosylphosphonic acid, tetracosylphosphonic acid docosylphosphonate, and hexicosylphosphonic acid. Phosphonic acid, octacosylphosphonic acid and the like.

As the fatty acid carboxylic acid compound, α-hydroxydecanoic acid, α-hydroxytetradecanoic acid, α
-Hydroxyhexadecanoic acid, α-hydroxyoctadecanoic acid, α-hydroxypentadecanoic acid, α-hydroxyeicosanoic acid, α-hydroxydocosanoic acid, α-hydroxytetracosanoic acid, α-hydroxyhexacosanoic acid, α-hydroxyoctacosane Acid, 2-bromohexadecanoic acid, 2-bromoheptadecanoic acid, 2-bromooctadecanoic acid, 2-bromoeicosanoic acid, 2-bromotetracolasanoic acid, 3-bromooctadecanoic acid, 3-bromoeicosanoic acid, 2 , 3-Dibromooctadecanoic acid, 2-fluorododecanoic acid, 2-fluorotetradecanoic acid, 2-
Fluorohexadecanoic acid, 2-fluorooctadecanoic acid, 2-fluoroeicosanoic acid, 2-fluorodocosanoic acid, 2-iodooctadecanoic acid, 3-iodohexadecanoic acid, 3-iodooctadecanoic acid, perfluorooctadecanoic acid, 2-oxo Dodecanoic acid, 2-oxotetradecanoic acid, 2-oxohexadecanoic acid, 2-oxooctadecanoic acid, 2-oxoeicosanoic acid, 2-oxotetracosanoic acid, 3-oxododecanoic acid, 3-oxotetradodecanoic acid, 3- Oxohexadecanoic acid, 3-oxooctadecanoic acid, 3-oxoeicosanoic acid, 3-oxotetracosanoic acid, 4-oxohexadecanoic acid, 4-oxooctadecanoic acid, 4-oxodocosanoic acid, dodecylmalic acid, tetradecylmalic acid , Hexadecyl malic acid, octadecyl malic acid Eicodecylmalic acid, docosylmalic acid, tetracosylmalic acid, dodecylthiomalic acid, tetradecylthiomalic acid, hexadecylthiomalic acid, octadecylthiomalic acid, eicosylthiomalic acid, docosylthiomalic acid, tetra Kosyl thiomalate, dodecyl dithiomalate, tetradecyl dimalate, hexadecyl dimalate, octadecyl dithiomalate, eicosyl dimalate, docosyl dimalate, tetracosyl dimalate, dodecyl butane diacid,
Tridecyl butane diacid, tetradecyl butane diacid, pentadecyl butane diacid, octadecyl butane diacid, eicosyl butane diacid, docosyl butane diacid, 2,3-dihexadecyl butane diacid, 2,3-dioctadecyl Butanedioic acid, 2-methyl-3-dodecylbutanedioic acid, 2-methyl-3-tetradecylbutanedioic acid, 2-methyl-3-hexadecylbutanedioic acid, 2-ethyl-3-dodecylbutanedioic acid, 2-propyl-3-decylbutanedioic acid, 2-octyl-3-hexadecylbutanedioic acid, 2-tetradecyl-3-octadecyldioic acid, dodecylmalonic acid, tetradecylmalonic acid, hexadecylmalonic acid, octadecylmalonic acid, Eicosylmalonic acid, docosylmalonic acid, tetracosylmalonic acid, didodecylmalonic acid, ditetradecylmalonic acid, dihe Sadecylmalonic acid, dioctadecylmalonic acid, dieicosylmalonic acid, didcosylmalonic acid, methyloctadecylmalonic acid, methyleicosylmalonic acid, methyldocosylmalonic acid, methyltetracosylmalonic acid, ethyloctadecylmalonic acid, ethyleicosylmalon Acid, ethyl docosylmalonic acid, ethyltetracosimalonic acid, 2-dodecyl-pentanedioic acid, 2-hexadecyl-pentanedioic acid, 2-octadecyl-pentanedioic acid, 2-eicosyl-pentanedioic acid, 2-docosyl-
Pentanedioic acid, 2-dodecyl-hexanedioic acid, 2-pentadecyl-hexanedioic acid, 2-octadecyl-hexanedioic acid, 2-eicosyl-hexanedioic acid, 2-docosyl-
Hexane diacid and the like can be mentioned.

When a combination of these electron-donating dye precursor and electron-accepting compound is used, a recording material capable of reversibly repeating decoloration and color development can be used (particularly). JP-A-5-124360). Furthermore,
Combinations of di- and triarylmethane dye precursors (thiolactones) with organic silver salts are also good (Japanese Patent Application Laid-Open No.
No. 501941).

Specific examples of the organometallic salt in the combination of the organometallic salt and the reducing agent include silver laurate, myristic acetic acid, silver palmitate vinegar, silver stearate, silver arakin vinegar and silver behen vinegar. Silver salt of an organic compound having an imino group such as a silver salt of a chain aliphatic carboxylic acid, a silver salt of benzotriazole, a silver salt of benzimidazole, a silver salt of carbazole and a silver salt of phthalazinone, and a sulfur-containing compound such as s-alkylthioglycolate. Silver salts of compounds, silver salts of aromatic carboxylic acids such as silver benzoate and silver phthalate, silver salts of sulfonic acids such as silver ethanesulfonate, silver salts of sulfinic acids such as silver o-toluenesulfinate Silver salts of phosphoric acid such as silver phenylphosphate, silver barbiturates, silver saccharinate, silver salts of salicylaldoxime and any mixtures thereof A. Among these compounds, long-chain aliphatic carboxylic acid silver salts are preferred, and silver behenate is particularly preferred. Further, behenic acid may be used together with silver behenate.

The reducing agent that can be used in the present invention is:
JP-A-53-1020, page 227, lower left column, line 14 to page 229, upper right column, line 11 can be used as appropriate. , Mono- or bisnaphthols, di- or polyhydroxynaphthalenes, di- or polyhydroxybenzenes, hydroxymonoethers, ascorbic acids, 3-pyrazolidones, pyrazolines, pyrazolones, reducing sugars, phenylenediamines, hydroxyl It is preferable to use amines, reductones, hydroxamines, hydrazides, amide oximes, N-hydroxyureas and the like. Among these compounds, particularly preferred are aromatic organic reducing agents such as polyphenols, sulfonamidephenols, and naphthols.

The color-forming components are (1) a method of using a solid dispersion, (2) a method of using an emulsified dispersion, (3) a method of using a polymer, and (4) a method of using a latex. And (5) a method of microencapsulation and the like, and among them, it is particularly preferable to use microencapsulation. In the method in which the color forming component is used by solid dispersion, it is generally dispersed together with a water-soluble polymer aqueous solution such as polyvinyl alcohol to several microns or less by a ball mill, a sand mill or the like. These dispersions are mixed after dispersing, and further, if necessary, an oil-absorbing pigment, a binder, a wax, a metal soap, an antioxidant, an ultraviolet absorber, a surfactant, an antistatic agent, an antifoaming agent, a conductive agent, a fluorescent agent A dye, a coloring dye and the like are added to form a thermosensitive coloring layer coating solution.

In the case of a thermosensitive recording material containing a color-forming component, an oil solution containing the color-forming component can be added to an aqueous solution of a water-soluble polymer and emulsified and dispersed using a colloid mill, a homogenizer, or ultrasonic waves. As the water-soluble polymer used at this time, a water-soluble polymer such as polyvinyl alcohol is used, and an emulsion or latex of a hydrophobic polymer may be used in combination. As the water-soluble polymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amino-modified polyvinyl alcohol, itaconic acid-modified polyvinyl alcohol, styrene-maleic anhydride copolymer, butadiene maleic anhydride copolymer,
Ethylene maleic anhydride copolymer, isobutylene maleic anhydride copolymer, polyacrylamide, polystyrene sulfonic acid, polyvinylpyrrolidone, ethylene-acrylic acid copolymer, gelatin and the like, among which carboxy-modified polyvinyl alcohol is particularly preferred. .
Examples of the hydrophobic polymer emulsion or latex include a styrene-butadiene copolymer, a carboxy-modified styrene-butadiene copolymer, and an acrylonitrile-butadiene copolymer. At this time, a conventionally known surfactant or the like may be added as necessary.

As a method of microencapsulation further containing a color-forming component, a conventionally known microcapsule method can be used. That is, the color-forming component and the microcapsule wall precursor are dissolved in an organic solvent that is hardly soluble or insoluble in water, added to an aqueous solution of a water-soluble polymer, emulsified and dispersed using a homogenizer, and the like. The polymer substance to be a wall can be prepared by forming a wall film at the oil / water interface. Specific examples of the polymer substance serving as the wall film of the microcapsule include, for example, polyurethane resin, polyurea resin, polyamide resin, polyester resin, polycarbonate resin, aminoaldehyde resin,
Melamine resin, polystyrene resin, styrene-acrylate copolymer resin, styrene-methacrylate copolymer resin, gelatin, polyvinyl alcohol and the like can be mentioned. Among these, a particularly preferable wall agent is a microcapsule having a wall film made of a polyurethane / polyurea resin.

Microcapsules having a polyurethane / polyurea resin wall film are prepared by mixing a microcapsule wall precursor such as polyvalent isocyanate into a core material to be encapsulated, and emulsifying the mixture in an aqueous solution of a water-soluble polymer such as polyvinyl alcohol. It is produced by dispersing, raising the liquid temperature and causing a polymer forming reaction at the oil droplet interface.

Here, some specific examples of the polyvalent isocyanate compound are shown below. For example, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-
Tolylene diisocyanate, 2,4-tolylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate, 3,
3'-diphenylmethane-4,4'-diisocyanate, xylene-1,4-diisocyanate, 4,4'-
Diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,
Diisocyanates such as 2-diisocyanate, cyclohexylene-1,2-diisocyanate and cyclohexylene-1,4-diisocyanate; 4,4 ', 4 "-triphenylmethane triisocyanate; toluene-2,
Triisocyanates such as 4,6-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2 ',
Tetraisocyanates such as 5,5'-tetraisocyanate, adducts of hexamethylene diisocyanate with trimethylolpropane, adducts of 2,4-tolylenediisocyanate with trimethylolpropane, and xylylenediisocyanate with trimethylolpropane Isocyanate prepolymers such as adducts and adducts of tolylene diisocyanate and hexanetriol, and the like. If necessary, two or more kinds can be used in combination. Of these, particularly preferred are those having three or more isocyanate groups in the molecule.

In the microencapsulation method, the oil shown by emulsification and dispersion can be used as the organic solvent for dissolving the coloring component. The same applies to a water-soluble polymer. The particle size of the microcapsules is 0.1-1.
0 μm is preferable, and more preferably 0.2 to 0.7 μm
Range.

Further, the recording material of the present invention may contain a heat-fusible substance (hereinafter referred to as a "sensitizer") in order to improve the thermal response.
May be contained in any layer constituting the recording material. Examples of the sensitizer include benzyl p-benzyloxybenzoate, β-naphthyl-benzyl ether, stearamide, stearyl urea, p-benzylbiphenyl, di (2-methylphenoxy) ethane, di (2-methoxy) Phenoxy) ethane, β-naphthol- (p-methylbenzyl) ether, α-naphthyl-benzyl ether,
1,4-butanediol-p-methylphenyl ether, 1,4-butanediol-p-isopropylphenyl ether, 1,4-butanediol-p-tert-octylphenyl ether, 1-phenoxy-2-
(4-ethylphenoxy) ethane, 1-phenoxy-2
-(4-chlorophenoxy) ethane, 1,4-butanediol phenyl ether, diethylene glycol-bis- (4-methoxyphenyl) ether, 4-ethoxyphenyl-p-chlorobenzyl ether, 1 (4-methoxy-phenoxy)- 2-phenoxy-propane, 1,3
-Bis- (4-methoxyphenoxy) propane, 3-methyl-4-chlorophenyl-p-methoxybenzyl ether, 3,5-dimethyl-4-chlorophenyl-p-methoxybenzyl ether, 4-chlorophenyl-p- Examples include methoxybenzyl ether, 1-phenoxy-2 (4-methoxy-phenoxy) -propane, dibenzyl oxalate, and di (p-methylbenzyl) oxalate. These sensitizers are used alone or as a mixture. In order to obtain sufficient thermal responsiveness, the sensitizer is dispersed in addition to one or both of the color-forming components or is dispersed at the same time, or after a heat eutectic with the color-forming component is prepared in advance and cooled, and then dispersed. You may.

As the binder to be used in combination, a compound which is soluble in water at 25 ° C. in an amount of 5% by weight or more is preferred. Specifically, polyvinyl alcohol (carboxy-modified, itaconic-acid-modified, maleic-acid-modified, silica-modified and the above-mentioned amino-modified) Including modified polyvinyl alcohol such as group modification), methylcellulose, carboxymethylcellulose, starches (including modified starch), gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, polyacrylamide, vinyl acetate- Examples include saponified polyacrylic acid copolymers. These binders are used not only at the time of dispersion but also for the purpose of improving the strength of the coating film. For this purpose, styrene-butadiene copolymer, vinyl acetate copolymer, acrylonitrile-
Latex binders of synthetic polymers such as butadiene copolymers, methyl acrylate / butadiene copolymers, and polyvinylidene chloride can also be used in combination. Also,
If necessary, a crosslinking agent for an appropriate binder may be added according to the type of the binder.

Examples of the pigment include calcium carbonate, barium sulfate, lithopone, wax, kaolin, calcined kaolin, silica and amorphous silica. As the metal soap, higher fatty acid metal salts are used, and zinc stearate, zinc myristate, calcium stearate, and aluminum stearate are used.

Examples of the wax include montan wax, paraffin wax, carnauba wax, microcrystalline wax, polyethylene wax and the like. The obtained heat-sensitive coating liquid is applied and dried on a high-quality paper, a high-quality paper having an undercoat layer, a synthetic paper, a plastic film, and the like, and then imparts smoothness by a calendering treatment to obtain a target heat-sensitive recording material. At this time, it is particularly preferable to use a support having a smoothness specified by JIS-8119 of 500 seconds or more, particularly 800 seconds or more from the viewpoint of dot reproducibility. To obtain a support having a smoothness of 500 seconds or more, (1)
Use a high-smoothness material such as synthetic paper or plastic film. (2) Provide an undercoat layer containing a pigment as a main component on the support. (3) Use a super calender or the like to smooth the support. Means to increase the

Further, if necessary, a back coat layer may be provided on the surface of the recording material support opposite to the color forming layer.
As the back coat layer, any known ones can be used as the back coat layer of the recording material, and the back coat layer may be coated with the above-mentioned i-polyvinyl alcohol and, if necessary, a crosslinking agent. If you include
Effects such as water resistance are further improved.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. The concentration used in the text is% by weight.

[0058]

Example 1 2-anilino-3-methyl-6-N-ethyl-N-tetrahydrofurfurylaminofluoran as a colorless electron-donating dye and 4-β-p-methoxyphenoxy as an electron-accepting compound Zinc ethoxysalicylate, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) as a hindered phenol compound
20 g each of butane and dibenzyl oxalate as a sensitizer were dispersed in a ball mill all day and night together with 100 g of a 5% aqueous solution of polyvinyl alcohol (55 mol% of isotacticity, 98.5 mol% of saponification degree, polymerization degree of 550). The particle size was reduced to 1.5 μm or less to obtain each dispersion. In addition, 80 g of calcium carbonate was dispersed with a homogenizer together with 160 g of a 0.5% sodium hexametaphosphate solution to obtain a pigment dispersion.

Each of the dispersions prepared as described above was treated with 5 g of an electron-donating colorless dye dispersion and 1 g of an electron-accepting compound dispersion.
0 g, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane dispersion 3
g, 10 g of dibenzyl oxalate dispersion and 5 g of calcium carbonate dispersion in a ratio of 3 g of a 21% zinc stearate emulsion, and glyoxal such that solid content of polyvinyl alcohol / pure glyoxal content = 10/1. A 40% solution was added to obtain a heat-sensitive coating solution.
This thermosensitive coloring layer coating solution is applied on a high-quality paper having a basis weight of 50 g / m ² by using a wire bar so that the dry weight of the coating layer is 5 g / m ² , and dried at 50 ° C. for 1 minute. I got

Examples 2 and 3 Instead of using the polyvinyl alcohol of 55 mol% of the isotacticity of Example 1, the polyvinyl alcohol of 60 mol% of isotacticity and the polyvinyl alcohol of 65 mol% (both having a saponification degree of 98.5%) were used. Mol%, degree of polymerization 55
Except that a heat-sensitive coating solution was prepared using each of the methods (1) and (2), a heat-sensitive recording paper was obtained in the same manner as in Example 1.

Examples 4 and 5 The procedure of Example 1 was repeated except that polyvinyl alcohol having a polymerization degree of 550 was used instead of polyvinyl alcohol having a polymerization degree of 1000 and 1750, respectively. Thermal recording paper was obtained in the same manner.

Examples 6 to 9 Carboxy-modified (1 mol% of itaconic acid) [Example 6], modified with a primary amino group (2 mol%) by changing to the non-modified i-polyvinyl alcohol of Example 2 Example 7], silanol-modified (1 mol%) [Example 8], sulfonic acid-modified (2 mol%) [Example 9] Sulfonic acid-modified (2 mol%) modified i-polyvinyl alcohol was used. A heat-sensitive recording paper was obtained in the same manner as in Example 2 except that a heat-sensitive coating solution was prepared.

Example 10 The procedure of Example 2 was repeated, except that a polyvinyl alcohol having a saponification degree of 96.0 mol% was used instead of the 98.5 mol% saponification degree i-polyvinyl alcohol to prepare a heat-sensitive coating solution. Thermal recording paper was obtained in the same manner as in Example 2.

Comparative Examples 1 and 2 Instead of using the isotacticity of 55 mol% of polyvinyl alcohol of Example 1, polyvinyl alcohol of 47.2 mol% of isotacticity (Comparative Example 1)
A thermosensitive recording paper was obtained in the same manner as in Example 1 except that a thermosensitive coating liquid was prepared using polyvinyl alcohol (Comparative Example 2) having an isotacticity of 53.5 mol%.

Example 11 [Preparation of Coating Solution for Protective Layer] 80 g of aluminum hydroxide (manufactured by Showa Denko KK, Hijilite H42) was added to sodium hexametaphosphate.
It was dispersed with a homogenizer together with 160 g of a 0.5% aqueous solution. 40 g of this dispersion, 600 g of a 25% aqueous solution of i-polyvinyl alcohol used in the protective layer of Example 9, 15 g of 40% glyoxal, and 40% zinc stearate dispersion (Himicron F930 manufactured by Chukyo Yushi Co., Ltd. .About.0.8 .mu.m) 183 g, respectively, to obtain a protective layer coating solution. This protective layer coating solution was applied on the thermosensitive coloring layer of the thermosensitive recording paper of Example 9 obtained above using a wire bar so that the dry coating amount was 3 g / m2.
It was dried in a 50 ° C. oven to obtain a heat-sensitive recording material.

Example 12 [Method for preparing capsule liquid] As a color former, 16 g of 2-anilino-3-methyl-6-N-ethyl-N-butyl-aminofluoran, Takenate D-110N (Takeda Pharmaceutical Co., Ltd.) Was added to a mixed solvent of 20 g of ethyl acetate and 5 g of methylene chloride for dissolution. The obtained solution was mixed with 50 g of an 8% by weight aqueous solution of the sulfonic acid-modified polyvinyl alcohol of Example 9, 20 g of water, and 0.5 g of a 2% by weight aqueous solution of sodium salt of dioctyl sulfosuccinate, and then mixed with the adjusted aqueous phase. Using an ace homogenizer (Nippon Seiki Co., Ltd.)
Emulsification was performed at 000 rpm for 5 minutes. Add 70 more to the resulting emulsion.
After the addition of g of water, an encapsulation reaction was carried out at 40 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 0.7 μm.

Instead of using the color former component liquid of Example 9, the above capsule liquid was added with the same color former solid amount,
A heat-sensitive recording material was obtained in the same manner as in Example 9, except that a 40% oxal aqueous solution was added so that the ratio of the total solid content of the sulfonic acid-modified polyvinyl alcohol to the pure oxal resistance was 10/1. Was.

Example 13 (Preparation of Leuco Dye-Dispersed Thermosensitive Recording Material) 2-anilino-3-methyl-6-N-ethyl-N-tetrahydrofurfurylaminofluorane was used as a colorless electron-donating colorless dye. 4- as an electron accepting compound as a developer
β-p-methoxyphenoxyethoxysalicylate zinc,
In Example 1, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane was used as a hindered phenol compound, and dibenzyl oxalate was used as a sensitizer in an amount of 20 g. 100g of i
-Polyvinyl alcohol) was dispersed with a 5% aqueous solution in a ball mill all day and night to reduce the average particle size to 1.5 μm or less to obtain each dispersion. In addition, 80 g of calcium carbonate was dispersed together with 160 g of a 0.5% sodium hexametaphosphate solution using an ace homogenizer (manufactured by Nippon Seiki Co., Ltd.) to obtain a pigment dispersion.

Each of the dispersions prepared as described above was mixed with 5 g of an electron-donating colorless dye (color former) dispersion, 10 g of an electron-accepting compound (color developer) dispersion, and 1,1,3-tris (2
-Methyl-4-hydroxy-5-tert-butylphenyl) butane dispersion 3 g, oxalic acid dibenzyl ester dispersion 10 g, calcium carbonate dispersion 5 g, and a 21% zinc stearate emulsion 3 g were mixed at a ratio of 3 g. A liquid was obtained. This thermosensitive coloring layer coating solution was applied with a basis weight of 50 g / m ^2.
Was applied using a wire bar so that the dry weight of the coating layer was 5 g / m ² , and dried at 50 ° C. for 1 minute to obtain a thermosensitive recording paper.

Example 14 (Preparation of Capsule Type Thermosensitive Recording Material Containing Leuco Dye) As color formers, 16 g of 2-anilino-3-methyl-6-N-ethyl-N-butyl-aminofluoran, Takenate D
20 g of 110N (manufactured by Takeda Pharmaceutical Co., Ltd., polyfunctional isocyanate, material for preparing capsules) 20 g of ethyl acetate
And methylene chloride in a mixed solvent of 5 g to dissolve. The resulting solution was mixed with 50 g of the 8% by weight aqueous solution of i-polyvinyl alcohol of Example 13, 20 g of water, and 0.5 g of a 2% by weight aqueous solution of sodium salt of dioctyl sulfosuccinate, and then mixed with the prepared aqueous phase. The mixture was emulsified at 10,000 rpm for 5 minutes using an ace homogenizer. After further adding 70 g of water to the obtained emulsion, an encapsulation reaction was carried out at 40 ° C. for 3 hours to prepare a capsule liquid having an average particle diameter of 0.7 μm. A heat-sensitive recording material was obtained in the same manner as in Example 13, except that the above capsule liquid was added in the same amount of the color former solid, instead of using the electron-donating colorless dye dispersion of Example 13.

Example 15 (Preparation of a diazonium salt / coupler coloring type thermosensitive recording material) (Preparation of a diazonium salt compound capsule solution) As a diazonium salt compound, a compound 2.8 having a maximum absorption wavelength of decomposition at 365 nm, 2.8. Parts, dibutyl sulfate 2.8
Part, 2,2-dimethoxy-1,2-diphenylethane-
0.56 parts of 1-one (Irgacure 651: trade name, trade name of Ciba-Geigy) was dissolved in 19.0 parts of ethyl acetate. Further, 5.9 parts of isopropyl biphenyl, which is a high boiling point solvent, and 2.5 parts of tricresyl phosphate were added to the above solution, and the mixture was heated and uniformly mixed. Xylylene diisocyanate / trimethylolpropane adduct (75% ethyl acetate solution Takenate D1)
7.6 parts (10N: trade name of Takeda Pharmaceutical Co., Ltd.) was further added to this solution, and the mixture was stirred uniformly. Example 1 to which 2.0 parts of a 10% by weight aqueous sodium dodecyl sulfonate solution was separately added
Was prepared, and the above diazonium salt compound solution was added thereto and emulsified and dispersed by a homogenizer. Water 20 was added to the obtained emulsion.
After adding the parts and homogenizing, the temperature was raised to 40 ° C. while stirring,
The encapsulation reaction was allowed to proceed for 3 hours. Thereafter, the liquid temperature was lowered to 35 ° C., and ion-exchange resin Amberlite IRA68 was used.
6.5 parts (manufactured by Organo), Amberlite IRC50
Add 13 parts (manufactured by Organo) and stir for an additional hour. Thereafter, the ion exchange resin was filtered to obtain a desired capsule liquid. The average particle size of the capsule was 0.64 μm.

[0072]

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(Preparation of Coupler Emulsion Dispersion) As a coupler, 3.0 parts of the compound b-1 shown below, 4.0 parts of triphenylguanidine, and 1,1- (p-hydroxyphenyl) -2-ethylhexane were used. 4.0 parts, 4,4 '-(p
-Phenylenediisopropylidene) diphenol to 8.
0 parts, 8.0 parts of 2-ethylhexyl-4-hydroxybenzoate, 2.0 parts of the compound shown in b-2 as an antioxidant, 1,1,3-tris (2-methyl-4-hydroxy-5- (tert-butylphenyl) butane;
0 part is dissolved in 10.5 parts of ethyl acetate, and 0.48 part of tricresyl phosphate, a high boiling point solvent, 0.24 part of diethyl maleate, Pionin A41C (manufactured by Takemoto Yushi Co., Ltd.)
Was added, and the mixture was heated and uniformly mixed. Separately, the mixture was added to 93 parts of the 8% by weight i-polyvinyl alcohol aqueous solution used in Example 1 and emulsified and dispersed by a homogenizer. The remaining ethyl acetate was evaporated from this emulsion to obtain a target emulsified dispersion.

[0074]

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(Preparation of Coating Solution) The above-mentioned diazonium salt compound capsule solution, coupler emulsified dispersion and styrene-butadiene rubber (SBR: SN307, manufactured by Sumitomo Nogatack Co., Ltd.) were each used at a diazonium salt compound / coupler ratio of 1/2. And a ratio of diazonium salt compound / styrene-butadiene rubber was 1 / 6.4 to prepare a target coating solution. Using this coating solution, a thermosensitive recording paper was obtained in the same manner as in Example 13.

Example 16 (Preparation of Organic Silver Salt / Reducing Agent Type Thermal Recording Material) Preparation of Silver Behenate 8.53 g of behenic acid was added to 200 g of water, heated to 90 ° C., and 1.0 g of NaOH was added to water. An aqueous solution dissolved in 25 g was added and cooled to 50 ° C. Next, an aqueous solution obtained by adding 4.3 g of AgNO3 to 25 g of water was dropped into the obtained solution over 1.5 hours to cause a reaction. The obtained reaction solution was added to a solution having a weight ratio of water to isopropanol of 1/1, stirred, and then centrifuged. After repeating such an operation three times, the obtained solid content was dried by blowing air at room temperature for two days and nights to obtain silver behenate having a water content of 0.5%.
In this case, instead of drying by blowing, dehydration with isopropanol / butyl acetate followed by centrifugation may be used.

Preparation of Coating Solution for Recording Layer (Preparation of Capsule Solution Encapsulating Silver Behenate) 7.6 g of prepared silver behenate, 20.0 g of n-butyl acetate, 5.0 g of isopropyl alcohol and polyvinyl butyral 2. 0 g, and mix with a homogenizer for 10,000.
The dispersion was performed at 0 rpm for 2 hours. 8.0 g of Takenate D-110N (capsule wall material) was added to the obtained dispersion.
The obtained silver behenate liquid was added to a solution (aqueous phase) obtained by mixing 40 g of the aqueous solution of 6% i-polyvinyl alcohol used in Example 1 and 0.3 g of an aqueous solution of 2% dioctyl sodium sulfosuccinate, 8,000 with a homogenizer
The mixture was emulsified and dispersed at 0 rpm for 10 minutes. 15 g of water was added to the obtained emulsified dispersion, mixed uniformly, and stirred at 40 ° C.
Then, an encapsulation reaction was carried out for 3 hours so that the average particle diameter of the capsules became 10 μm to obtain a capsule liquid containing silver behenate.

(Preparation of Developer Emulsified Dispersion) Bisphenol B 0.5 g, propyl gallate 5 g, phthalazinone (development accelerator) 3 g, benzoxazine dione 0.2
g, 2 g of tribromomethylbenzimidazole, 4 g of ethyl acetate, 3 g of methyl cellosolve, 3 g of tetrahydrofuran and 0.5 g of tricresyl phosphate were uniformly mixed. The obtained developer solution was used for i-
15 g of a 10% aqueous polyvinyl alcohol solution, 1 g of a 1% aqueous solution of sodium benzenethiosulfonate and a 6% aqueous solution of sodium dodecylbenzenesulfonate were added to a mixed solution, and the mixture was homogenized at 10,000 rpm.
m for 10 minutes. Ethyl acetate, methyl cellosolve and tetrahydrofuran were evaporated and removed from the obtained emulsified dispersion under reduced pressure to obtain a developer emulsified dispersion having a particle diameter of 0.6 μm.

(Preparation of Coating Solution) 30 g of a prepared capsule solution containing silver behenate and 10 g of a developer emulsified dispersion were mixed to obtain a coating solution, and a thermosensitive recording material was prepared in the same manner as in Example 13. I got

Examples 17 to 20 (Preparation of Coating Solution for Protective Layer) 80 g of aluminum hydroxide (Higilite H42 manufactured by Showa Denko KK) was dispersed together with 160 g of a 0.5% aqueous solution of sodium hexametaphosphate in a homogenizer. 40 g of this dispersion, 600 g of a 15% aqueous solution of i-polyvinyl alcohol used in Example 1, 40%
183 g of a zinc stearate dispersion (High Micron F930, manufactured by Chukyo Yushi Co., Ltd., average particle size: 1 to 0.8 μm) was added to obtain a protective layer coating liquid. This protective layer coating solution was applied on the heat-sensitive coloring layer of the heat-sensitive recording papers of Examples 13 to 16 by a wire bar so as to have a dry coating amount of 3 g / m ² , and dried in a 50 ° C. oven. Thus, the heat-sensitive recording materials of Examples 17 to 20 were obtained.

Examples 21 to 22 In place of the i-polyvinyl alcohol used for preparing the protective layer coating liquids of Examples 17 to 20, i-polyvinyl alcohol used in Example 2 was used.
A protective layer coating solution was prepared in the same manner as in Examples 17 to 20, except that the i-polyvinyl alcohol (Example 22) used in Example 3 and the i-type polyvinyl alcohol (Example 22) used in Example 3 were used. The thermosensitive recording materials of Examples 21 to 22 were obtained by coating the thermosensitive recording materials prepared in No. 15 respectively.

Example 23 In place of the modified polyvinyl alcohol used for preparing the protective layer coating liquids of Examples 17 to 20, the non-modified polyvinyl alcohol used in Comparative Example 1 (PVA105: manufactured by Kuraray Co., Ltd., isotacticity) (47.2 mol%), except that a protective layer coating solution was prepared in the same manner as in Examples 17 to 20, and was applied on the heat-sensitive recording material prepared in Example 15,
The thermosensitive recording material of Example 23 was obtained.

Example 24 In the diazonium salt compound capsule solution and the coupler emulsified dispersion of Example 19, unmodified polyvinyl alcohol (PV
A photosensitive recording material of Example 24 was obtained in the same manner as in Example 19 except that A105) was used.

Examples 25 to 26 In Example 19 to Example 20, except that a 40% solution of glyoxal was added so that the solid content of i-polyvinyl alcohol used / glyoxal pure content = 10/1. In the same manner as in Examples 20 to 20, the heat-sensitive recording materials of Examples 25 to 26 were obtained.

Examples 27 to 28 Thermosensitive recording materials were obtained in the same manner as in Examples 17 and 18, except that 15 g of 40% glyoxal was further added to the protective layer solution.

Comparative Examples 3 and 4 In Examples 13 and 14, the unmodified polyvinyl alcohol (P
The heat-sensitive recording materials of Comparative Examples 3 and 4 were obtained in the same manner as in Examples 13 and 14, except that VA105) was used.

Comparative Examples 5 to 6 In Examples 19 and 20, the unmodified polyvinyl alcohol (P
Except for using VA105), the heat-sensitive recording materials of Comparative Examples 5 to 6 were obtained in the same manner as in Examples 19 to 20.

Comparative Example 7 A heat-sensitive recording material of Comparative Example 7 was obtained in the same manner as in Example 19, except that the degree of saponification of the i-polyvinyl alcohol used was 80%.

Example 29 The procedure of Example 1 was repeated, except that the isotacticity of polyvinyl alcohol of 55 mol% was replaced with the isotacticity of 85 mol% of polyvinyl alcohol dissolved at 120 ° C. in an autoclave. Example 1
A thermosensitive recording paper was obtained in the same manner as described above.

Comparative Example 8 Instead of using the isotacticity 85 mol% polyvinyl alcohol of Example 29, syndiotacticity 85 mol% polyvinyl alcohol (saponification degree 9)
An attempt was made to obtain a thermosensitive recording paper in the same manner as in Example 29 except that 8.5 mol% and a polymerization degree of 550) were used. However, since this polyvinyl alcohol has low water solubility, a uniform dispersion was prepared. I couldn't.

Comparative Example 9 The heat-sensitive recording material of Comparative Example 9 was obtained in the same manner as in Example 29 except that the i-modified polyvinyl alcohol used had an i-modification ratio of 92 mol%. However, uniform dispersions could not be prepared due to the low water solubility of the polyvinyl alcohol.

The heat-sensitive recording material obtained as described above is subjected to a surface treatment with a calender, and has a smoothness of JIS-81.
Adjustment was made so that the smoothness specified in No. 19 was 500 ± 50 seconds to obtain a thermosensitive recording material.

[Test Method and Evaluation Method] The heat-sensitive recording material obtained as described above is subjected to a surface treatment with a calender so that the smoothness becomes 500 ± 50 seconds as the smoothness specified by JIS-8119. The temperature was adjusted to obtain a thermosensitive recording material.

Water resistance After printing using a Kyocera printing tester, apply water, attach and dry, peel off and observe the state of the coating layer.
No change in coating layer, (B) hardly any coating layer was removed,
(C) The coating layer is very slightly removed, but the printed portion is readable. (D) The coating layer is removed, but the printed portion is readable. (E) The coating layer is removed. Was intense and the printed characters could not be read. (C) and above are practical.

Chemical resistance After printing using a Kyocera printing tester, spread the hand cream evenly on the finger, press it against the printed portion and observe (A)
There is no change in the printed part, (B) There is a slight change in the printed part, but the printed part can be read clearly, (C) There is smear and decoloration, but the printed part can be read somehow, (D) blur In addition, the determination was made in four steps such that the decoloring was severe and the printed characters could not be read. (B) and above are practical.

Runability Printing was carried out using a Kyocera printing tester, and the degree of sticking was determined as follows: (A) no occurrence of sticking; (B) printing unevenness was observed but white spotting was not observed; (C) very slight It was determined in four steps, such as white spots and (D) white streaks were generated on the entire surface. (B) and above are also practical.

The test sample was conditioned for at least one hour in a 23 ° C./65% RH environment. Tables 1 and 2 show the test results. In addition, the coating liquid of the protective layer in each Example did not cause gelation after the preparation of the coating liquid, and the period in which the coating could be performed stably was 1 day or more. Therefore, the recording material of the present invention was excellent in production suitability.

[0098]

[Table 1]

[0099]

[Table 2]

From the results shown in Tables 1 and 2, the recording material using the polyvinyl alcohol having the isotacticity of less than 55 mol% in the color-forming layer is inferior in running property and chemical resistance, and has extremely low water resistance. 55 isotacticity
It can be seen that the recording material of the present invention using polyvinyl alcohol of at least mol% is a heat-sensitive recording material having good water resistance, chemical resistance and running properties.

[0101]

As described above, according to the present invention, water resistance is high under temperature conditions that do not impair the properties of the color-forming substance,
It is possible to obtain a recording material having excellent running properties without sticking or scum on the surface of the recording material and excellent chemical resistance.

Claims (6)

[Claims] 1. A recording material comprising a support having thereon a color-forming layer containing at least a substantially colorless color-forming component A and a substantially colorless color-forming component B which reacts with said color-forming component A to form a color. A recording material, wherein the coloring layer contains a polyvinyl alcohol-based resin having an isotacticity of 55 mol% to 90 mol% by diat display and a saponification degree of 85 mol% or more. 2. The color-forming layer according to claim 1, further comprising a polyvinyl alcohol-based resin and a crosslinking agent for crosslinking the polyvinyl alcohol-based resin.
Recording material described in 1. 3. The method according to claim 1, wherein the crosslinking agent is selected from the group consisting of an epoxy compound, a blocked isocyanate, a vinyl sulfone compound, an aldehyde compound, a methylol compound, boric acid, a carboxylic anhydride, a silane compound, a chelate compound and a halogen compound. The recording material according to claim 2, wherein 4. A color-forming layer comprising at least a substantially colorless color-forming component A and a substantially colorless color-forming component B which forms a color by reacting with the color-forming component A on a support; In a recording material provided with a protective layer mainly composed of a pigment and a binder, at least one of the coloring layer and the protective layer has an isotacticity of 55 by diat display.
A recording material comprising a polyvinyl alcohol-based resin having a mol% of 90 mol% and a saponification degree of 85 mol% or more. 5. The recording material according to claim 4, wherein the protective layer contains a polyvinyl alcohol-based resin and a crosslinking agent for crosslinking the polyvinyl alcohol-based resin. 6. The method according to claim 1, wherein the crosslinking agent is selected from the group consisting of an epoxy compound, a blocked isocyanate, a vinyl sulfone compound, an aldehyde compound, a methylol compound, boric acid, a carboxylic anhydride, a silane compound, a chelate compound and a halogen compound. The recording material according to claim 5, characterized in that: