JPH06122270A - Recording material - Google Patents

Abstract

PURPOSE:To improve color-developing density, color-developing sensitivity and each shelf stability of a non-image section and an image section particularly respectively by containing at least one of compounds shown in specific general formula as the electron acceptable compound of a pressure-sensitive recording material, etc. CONSTITUTION:Electron donative colorless dyes and an electron acceptable compound are used as a recording material such as a pressure-sensitive recording material. At least one of compounds shown separately in general formula mentioned is contained as the electron acceptable compound at that time. Where X and Y may be the same or different, and represent a hydrogen atom, a halogen atom, a hydroxyl group, a carboxyl group, an alkoxycarbonyl group, an alkyl group, an alkoxy group, an allyl group, an aryl group, an aralkyl group or a cycloalkyl group respectively. R represents the hydrogen atom, the alkyl group, an aralkyl group or an aryloxyalkyl group. Accordingly, color-developing density, color-developing sensitivity and each shelf stability of a non-image section and an image section are improved particularly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material using an electron-donating colorless dye and an electron-accepting compound, such as a pressure-sensitive recording material and a heat-sensitive recording material. The present invention relates to an image portion and a recording material having excellent storage stability in the image portion.

[0002]

2. Description of the Related Art Recording materials using an electron-donating colorless dye and an electron-accepting compound are pressure-sensitive paper, thermal paper, photosensitive pressure-sensitive paper,
It is already well known as an electrically conductive recording paper and a thermal transfer paper. For example, British Patent No. 2140449 and US Patent No. 448.
No. 0052, No. 4436920, Japanese Patent Publication No. 60-239
92, JP-A Nos. 57-179836 and 60-123.
For details, see No. 556 and No. 60-123557.

As a recording material, in recent years, studies have been earnestly conducted to improve characteristics such as (1) color density and color sensitivity (2) storage stability of non-image area and image area. Conventional electron-accepting compounds for the electron-donating colorless dye include bisphenol A, p-hydroxybenzoic acid esters,
Various types of bis- (4-hydroxyphenyl) sulfones are known, but all have color density, color sensitivity, storage stability of non-image area and image area (weather resistance, chemical resistance, plasticizer resistance). Etc. had some drawbacks. For example,
When bis- (3-phenyl-4-hydroxyphenyl) sulfone was used in a heat-sensitive recording material, the non-image area storability was poor, such as the background area being fogged with a marker or a highlighter pen. The present inventors have found that specific compounds are effective in improving these properties.

[0004]

DISCLOSURE OF THE INVENTION The present invention is directed to color density, color sensitivity, storage stability of non-image area and image area (weather resistance,
The present invention provides a recording material having good chemical resistance and plasticizer resistance) and satisfying other requirements to be met.

[0005]

The present invention provides a recording material using an electron-donating colorless dye and an electron-accepting compound, wherein at least one of the compounds represented by the following general formula (1) is used as the electron-accepting compound. It is a recording material characterized by containing. General formula (1)

[0006]

[Chemical 2]

In the formula, X and Y may be the same or different and each is a hydrogen atom, a halogen atom, a hydroxy group,
A carboxyl group, an alkoxycarbonyl group, an alkyl group, an alkoxy group, an allyl group, an aryl group, an aralkyl group, or a cycloalkyl group, and R represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryloxyalkyl group.

In the general formula (1), the group represented by X is a hydrogen atom, a hydroxy group, a carboxyl group, or a carbon number of 1 to 1.
7 alkoxycarbonyl group, fluorine atom, chlorine atom,
Bromine atom, alkyl group having 1 to 5 carbon atoms, alkoxy group having 1 to 5 carbon atoms, allyl group, aryl group having 7 to 10 carbon atoms, aralkyl group having 7 to 10 carbon atoms, or 5 to 7 carbon atoms
Is preferred, and a hydrogen atom, a hydroxy group, a carboxyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, is
o-propoxycarbonyl group, n-butylcarbonyl group, iso-butyloxycarbonyl group, chlorine atom, methyl group, ethyl group, n-propyl group, iso-propyl group, tert-butyl group, sec-butyl group, methoxy group , Ethoxy group, allyl group, phenyl group, benzyl group,
A cyclohexyl group, an α-phenylpropyl group, and an α-phenylallyl group are more preferred.

In the general formula (1), the group represented by R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a carbon atom having 7 carbon atoms.
To 20 aralkyl groups, or aryloxyalkyl groups having 8 to 20 carbon atoms are preferable, and particularly hydrogen atom, methyl group, ethyl group, n-propyl group, iso-propyl group,
n-butyl group, tert-butyl group, sec-butyl group, iso-butyl group, n-amyl group, iso-amyl group, n-hexyl group, n-octyl group, benzyl group, p
-Methylbenzyl group, p-ethylbenzyl group, pn-
Propylbenzyl group, p-iso-propylbenzyl group, methoxybenzyl group, chlorobenzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, phenoxyethyl group, methoxyphenoxyethyl group, chlorophenoxyethyl group, methylphenoxyethyl group, 1-methyl 2-phenoxyethyl group, 1-methyl-2- (methoxyphenoxy) ethyl group, 1-methyl-2- (methylphenoxy) ethyl group, 2-naphthoxyethyl group, 1-
A naphthoxyethyl group and a 1-methyl-2- (2-naphthoxy) ethyl group are more preferable.

[0010]

[Chemical 3]

As the electron-donating colorless dye used in the present invention, conventionally known triphenylmethanephthalide compounds, fluorane compounds, phenothiazine compounds, indolylphthalide compounds, leukoauramine compounds, rhodamine lactams. Various compounds such as a series-based compound, a triphenylmethane-based compound, a triazene-based compound, a spiropyran-based compound, and a fluorene-based compound are known.

Specific examples of the phthalides include US Reissue Patent Specification No. 23024 and US Patent Specification No. 3491111.
No. 3,491,112, No. 3,491,116 and No. 3,509,174, and specific examples of fluoranes are U.S. Pat. Nos. 3,624,107, 3,627,787.
No. 3641011, No. 3462828, No. 3
681390, 3920510, and 3959.
No. 571, specific examples of spiro dipyrans are US Pat. No. 3,971,808, and pyridine-based and pyrazine-based compounds are US Pat. Nos. 3775424, 3853.
No. 869, No. 4264318, and specific examples of the fluorene compound are described in JP-A-63-94878. Examples thereof will be given below, but the electron donating colorless dye used in the present invention is not limited thereto.

3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p
-Dimethylaminophenyl) phthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl) phthalide, 3- (p-dimethylaminophenyl) -3- (2-methylindole -3-yl)
Phthalide, 3,3-bis (1,2-dimethylindol-3-yl) -5-dimethylaminophthalide, 3,3-
Bis (1,2-dimethylindol-3-yl) -6-
Dimethylaminophthalide, 3,3-bis (9-ethylcarbazol-3-yl) -6-dimethylaminophthalide.

3- (2-ethoxy-4-diethylaminophenyl) -3- (1-normaloctyl-2-methylindol-3-yl) phthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-Normal octyl-2-methylindol-3-yl) -4-azaphthalide, 3,3-bis (1-normal octyl-2)
-Methylindol-3-yl) phthalide, 3,3-bis (2-phenylindol-3-yl) -6-dimethylaminophthalide, 3-p-dimethylaminophenyl-
Triarylmethane dyes such as 3- (1-methylpyrrol-3-yl) -6-dimethylaminophthalide, 4,
4'-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenyl-leuco auramine, N-
Diphenylmethane dyes such as 2,4,5-trichlorophenylleuco auramine, and thiazine dyes such as benzoyl leuco methylene blue and p-nitrobenzoyl leuco methylene blue.

3-methyl-spiro-dinaphthopyran, 3
-Ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho (6'-methoxybenzo) spiropyran, 3-propyl-spiro-dibenzopyran and other spiro dyes , Rhodamine-B-anilinolactam, rhodamine (p-nitroanilino) lactam, rhodamine (o-chloroanilino) lactam and the like. 2-methoxy-6-diethylaminofluorane, 3-methoxy-6-diethylaminofluorane, 2
-T-butyl-6-diethylaminofluorane, 2-chloro-6-diethylaminofluorane, 2-chloro-3
-Methyl-6-diethylaminofluorane, 2,3-dimethyl-6-diethylaminofluorane, 2-methyl-
6- (N-ethyl-p-toluidino) fluorane, 2-
N-acetyl-N-methylamino-6-diethylaminofluorane, 2-N-octylamino-6-diethylaminofluorane.

2-dibenzylamino-6-diethylaminofluorane, 2-N-methyl-N-benzylamino-
6-diethylaminofluorane, 2-N-chloroethyl-N-methylamino-6-diethylaminofluorane,
2-N-dioctylamino-6-diethylaminofluorane, 2-anilino-3-methyl-6- (N-ethyl-
p-toluidino) fluorane, 2- (p-toluidino)
-3-Methyl-6- (N-ethyl-p-toluidino) fluorane, 2-anilino-3-methyl-6-diethylaminofluorane.

2-anilino-3-methyl-6-dibutylaminofluorane, 2- (2-carbomethoxy-phenylamino) -6-diethylaminofluorane, 2-anilino-3-methyl-6- (N-ethyl-) N-isoamylamino) fluorane, 2-anilino-3-methyl-6-
(N-cyclohexyl-N-methylamino) aminofluorane, 2-anilino-3-methyl-6-pyrrolidinofluorane, 2-anilino-3-methyl-6-piperidinoaminofluorane, 2- (2 , 4-dimethylanilino)
-3-Methyl-6-diethylanilinofluorane, 2-
(2,6-Dimethylanilino) -3-methyl-6-diethylanilinofluorane.

2- (o-chlorophenylamino) -6-
Diethylaminofluorane, 2- (o-chlorophenylamino) -6-dibutylaminofluorane, 2-anilino-3-methyl-6- (N-ethyl-N-tetrahydrofurfurylamino) fluorane, 2-anilino-3- Methyl-6- (N-methyl-N-n-butylamino) fluorane, 2-anilino-3-methyl-6- (N-ethyl-N-isobutylamino) fluorane, 2-diphenylamino-3-methoxy-6 -Ethyl-Np-tolylaminofluorane, 2-bis-p-tolylamino-3-methoxy-6-ethyl-Np-tolylaminofluorane, 2-bis-p-anisylamino-3-methoxy-6
-Ethyl-N-p-tolylaminofluorane.

2-anilino-3-methyl-6- (N-methyl-Nn-hexylamino) fluorane, 2-anilino-3-methyl-6- (N-ethyl-Nn-hexylamino) fluorane , 2-anilino-3-methyl-6
-(N-ethyl-N-cyclopentylamino) fluorane, 2-anilino-3-methyl-6-N-ethyl-N-
[3- (p-Ethylphenoxy) propyl] aminofluorane, 2-anilino-3-methyl-6-N-propyl-N- [3- (p-methoxyphenoxy) propyl] aminofluorane, 2-anilino- 3-methyl-6-N-
Propyl-N-3-ethoxypropylaminofluorane, 2-anilino-3-methyl-6-N-ethyl-N-
Fluorane dyes such as 3-ethoxypropylaminofluorane.

The electron-donating colorless dye used in the present invention is, of course, not limited to these dyes, and two or more dyes may be used in combination. The electron-accepting compound according to the present invention is a conventionally known phenol derivative, salicylic acid derivative, metal salt of aromatic carboxylic acid,
It can be used in combination with a compound such as acid clay, bentonite, novolac resin, metal-treated novolac resin, and metal complex. Examples of these are Japanese Examined Patent Publication Nos. 40-9309 and 45-14039.
JP-A-56-140483 and 48-51510.
No. 57-210886, No. 58-87089,
59-11286, 60-76795, 61
-95988 and the like.

Examples of these are, for example, bisphenol A, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) heptane, 1,1-bis (4- Hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl)
-2-ethylhexane, 1,1-bis (3-chloro-4)
-Hydroxyphenyl) -2-ethylbutane, bis (3
-Allyl-4-hydroxyphenyl) sulfone, 1,7
-Bis (4-hydroxyphenylthio) -3,5-dioxaheptane.

(4-hydroxyphenyl)-(4-isopropoxyphenyl) sulfone, 4-hydroxybenzoic acid benzyl ester, 2,4-dihydroxybenzoic acid-
β-phenoxyethyl ester, 2,4-dihydroxybenzoic acid-α-methyl-β- (3-methoxyphenoxy) ethyl ester, 1,3-bis (4-hydroxyphenyl) propane, 2- (2,4-dihydroxy) Examples thereof include phenyl) -2-phenylpropane and 3,5-bis (α-methylbenzyl) salicylate zinc.

When the recording material of the present invention is used for thermal paper, it is disclosed in JP-A-62-114989 and JP-A-1-87729.
It takes the form as described in No. 1 specification. Specifically, the electron-donating colorless dye and the electron-accepting compound are pulverized and dispersed in a dispersion medium to a particle size of 10 μm or less, preferably 3 μm or less. As the dispersion medium, an aqueous polymer solution having a concentration of about 0.5 to 10% is generally used, and the dispersion is performed using a ball mill, a sand mill, a horizontal sand mill, an attritor, a colloidal mill or the like.

The weight ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably 1:10 to 1: 1 by weight, more preferably 1: 5 to 2: 3. At that time, a thermofusible substance may be contained in the thermosensitive coloring layer in order to improve the thermal response. Typical examples of the heat-fusible substance include aromatic ethers, thioethers, esters and / or aliphatic amides or ureides.

Examples of these are disclosed in JP-A-58-57989,
58-87094, 61-58789, 62.
-109681, 62-2132674, 63-
151478, 63-235961, JP-A-2-
No. 184489 and No. 2-215585.

Examples of heat-fusible substances are phenethyl biphenyl ether, benzyloxynaphthalene, benzyl biphenyl, 1,2-diphenoxyethane, 1,2-
Di-m-tolyloxyethane, 1-phenoxy-2-p
-Methoxyphenoxyethane, 1-p-methoxyphenoxy-2-o-chlorphenoxyethane, 1,2-di-
p-fluorophenoxyethane, 1,3-di-p-methoxyphenoxypropane, 1,2-di-p-methoxyphenoxypropane, 1-phenoxy-2-p-methoxyphenoxypropane, 1-p-methoxyphenoxyethoxy- 2-p-methoxyphenoxyethane, 1,2-di-p-methoxyphenylthioethane, p-methoxybenzyloxytolylmethane, (4-methoxybenzyloxy)-(3-methyl-4-chlorophenyl) methane, p
-Chlorobenzyloxy-p-ethoxyphenylmethane and the like.

These are used at the same time as the electron-donating colorless dye or at the same time as being finely dispersed at the same time as the electron-accepting compound. The amount used of these is 20% or more and 30% with respect to the electron-accepting compound.
It is added in a weight ratio of 0% or less, especially 40% or more and 150%
The following are preferred. If necessary, additives are added to the coating liquid thus obtained in order to meet various requirements. As an example of the additive, an oil absorbing substance such as an inorganic pigment or a polyurea filler is dispersed in a binder in order to prevent the recording head from being soiled during recording. For fatty acids,
Metal soap or the like is added. Therefore, in general, in addition to direct electron-donating colorless dyes and electron-donating compounds for color development, heat-fusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, defoamers, conductive agents, fluorescent dyes, surface active agents An additive such as an agent is coated on the support to form a recording material.

If desired, a protective layer may be provided on the surface of the heat-sensitive recording. Two or more protective layers may be laminated if necessary. Further, in order to correct the curl balance of the support or to improve the chemical resistance from the back surface, a coating liquid similar to the protective layer may be applied to the back surface. An adhesive may be applied to the back surface, and release paper may be further combined to form a label.

Usually, the electron-donating colorless dye and the electron-accepting compound are dispersed and applied in a binder. Water-soluble binders are generally used, and polyvinyl alcohol, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride. Examples thereof include salicylic acid copolymer, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivative, casein, gelatin and the like. Further, for the purpose of imparting water resistance to these binders, a water resistant agent is added, or a hydrophobic polymer emulsion, specifically,
Styrene-butadiene rubber latex and acrylic resin emulsion can also be added.

The obtained heat-sensitive coating liquid is applied to high-quality paper, high-quality paper having an undercoat layer, synthetic paper, plastic film and the like. At this time, it is particularly preferable from the viewpoint of dot reproducibility to use a support having a smoothness of 500 seconds or more, particularly 800 seconds or more as defined by JIS-8119. As the pigment for the case where the undercoat layer containing a pigment as a main component is provided on the support, all the general organic or inorganic pigments can be used, but in particular,
Oil absorption specified by JIS-K5101 is 40cc / 10
It is preferably 0 g or more, and specifically calcium carbonate, barium sulfate, titanium oxide, talc, wax stone, kaolin, calcined kaolin, aluminum hydroxide, amorphous silica, urea formalin resin powder, polyethylene resin powder and the like. Can be mentioned. When these pigments are applied to a support, the amount of pigment is 2 g / m ² or more, preferably 4 g / m ^2.
m ² or more.

The binder used in the undercoat layer is
Examples thereof include water-soluble polymers and water-soluble binders, and the binders may be used alone or in combination of two or more. As the water-soluble polymer, methyl cellulose, carboxymethyl cellulose, hydroxytyl cellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate, Examples thereof include polyvinyl alcohol and polyacrylamide.

As the water-soluble binder, synthetic rubber latex or synthetic resin emulsion is generally used.
Examples thereof include styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, and vinyl acetate emulsion. The amount of binder used is 3 for pigments.
-100% by weight, preferably 5-50% by weight. Wax, decoloring inhibitor, surfactant, etc. may be added to the undercoat layer.

The pigment used as the additive of the present invention includes kaolin, calcined kaolin, talc, wax, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, lithopone, amorphous silica and colloidal. Examples thereof include silica, calcined stone, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, mica, microballoons, urea-formalin filler, polyester particles, and cellulose filler.

Examples of the metal soap include higher fatty acid polyvalent metal salts such as zinc stearate, aluminum stearate, calcium stearate and zinc oleate. Further, in the present invention, it is preferable to use a wax having a melting point of 40 to 120 ° C. together from the viewpoint of the head matching property with respect to the facsimile. The wax having a melting point of 40 to 120 ° C. is preferably paraffin wax, polyethylene wax, carnauba wax, microcrystalline wax, candelia wax, montan wax, and fatty acid amide wax, and particularly, paraffin having a melting point of 50 to 100 ° C. Wax, montan wax and methylol stearamide are preferred. The amount of wax used is 5 to 200% by weight, preferably 20 to 150% by weight of the electron-donating colorless dye.

The hindered phenol compound is preferably a phenol derivative in which at least one of the 2-position and the 6-position is substituted with a branched alkyl group. UV absorbers include cinnamic acid derivatives, benzophenone derivatives,
Benzotriazole phenol derivatives and the like, for example, butyl α-cyano-β-phenylcinnamate, o-benzotriazole phenol, o-benzotriazole-p-chlorophenol, o-benzotriazole-2,4-di-te.
rt-butylphenol, o-benzotriazolyl-
2,4-di-tert-octylphenol and the like.

As the waterproofing agent, N-methylol urea,
Water-soluble initial condensates such as N-methylol melamine and urea-formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic crosslinking agents such as boric acid and borax,
Examples include blend heat treatment of polyacrylic acid, methyl vinyl ether-maleic acid copolymer, isobutylene-maleic anhydride copolymer, and the like. Materials used for the protective layer include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, vinyl acetate-acrylamide copolymer,
Silicon modified polyvinyl alcohol, starch, modified starch, methyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, gelatins, gum arabic, casein, styrene-maleic acid copolymer hydrolyzate, styrene-maleic acid copolymer half ester hydrolyzate,
Water-soluble polymers such as isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivative, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate, etc. and styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene Water-insoluble polymers such as rubber latex and vinyl acetate emulsion are used.

Further, for the purpose of improving the matching property with the thermal head, a pigment, metal soap, wax, water-proofing agent and the like may be added to the protective layer. Further, when the protective layer is coated on the thermosensitive coloring layer, a surfactant may be added to obtain a uniform protective layer. As the surfactant, a sulfosuccinic acid-based alkali metal salt or a fluorine-containing surfactant is used. Specifically, sodium salts such as di- (n-hexyl) sulfosuccinic acid and di- (2-ethylhexyl) sulfosuccinic acid, or ammonium salts are preferable, but anionic surfactants are effective.

When used for pressure sensitive paper, US Pat. No. 25
No. 05470, No. 25054571, No. 250548
No. 9, No. 2548366, No. 2712507, No. 2
No. 730456, No. 2730457, No. 310340
It can take various forms as described in prior patents such as No. 4, No. 3418250 and No. 4010038. Most commonly it consists of at least a pair of sheets containing separately an electron donating colorless dye and an electron accepting compound.

Regarding the method of manufacturing capsules, US Pat.
Nos. 800457 and 2800458, methods utilizing coacervation of hydrophilic colloid sol, British Patents 867797, 950443 and 9
There are methods described in 89264 and 1091076.

Generally, an electron-donating colorless dye is used alone or in a mixture, and a synthetic oil such as a solvent (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, chlorinated paraffin, etc .; cotton oil,
A color former sheet by dissolving it in a vegetable oil such as castor oil; an animal oil; a mineral oil or a mixed oil thereof, etc., containing it in a microcapsule, and coating it on paper, high-quality paper, plastic sheet, resin coated paper, etc. To get

Further, the electron-accepting compound and, if necessary, additives are dispersed alone or in a mixture in a binder such as styrene-butadiene latex or polyvinyl alcohol, and together with the pigment, paper, plastic sheet, resin coated paper, etc. A color developer sheet is obtained by applying it to the support.

As the binder, it is preferable to use a carboxy-modified styrene-butadiene latex in combination with a water-soluble polymer from the viewpoint of light resistance and water resistance. Further, as the pigment, it is preferable to use calcium carbonate having an average particle diameter of 5.0 μm or less in an amount of 60% by weight or more based on all pigments from the viewpoint of color developing ability.

The use amount of the electron-donating colorless dye and the electron-accepting compound depends on the desired coating thickness, the form of the pressure-sensitive recording paper, the capsule manufacturing method, and other conditions, and may be appropriately selected according to the conditions. A person skilled in the art can easily determine this usage amount.

[0044]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In the examples, unless otherwise specified, weight% is expressed.

Example 1 2-anilino-3-methyl- which is an electron-donating colorless dye
20 g each of 6-N-methyl-N-n-butylaminofluorane, the compound of the specific example (1) which is an electron-accepting compound, and 2-naphthylbenzyl ether which is a heat-fusible compound
100 g of 5% polyvinyl alcohol (Kuraray PVA
105) Dispersed with an aqueous solution in a ball mill all day and night to give a volume average particle size of 2μ. Meanwhile, baked kaolin (anis)
80 g of ilex-93) was dispersed by a homogenizer together with 160 g of a 0.5% solution of sodium hexametaphosphate.

Dispersing as described above, each dispersion was prepared by dispersing 5 g of an electron-donating colorless dye dispersion and 10 g of an electron-accepting compound dispersion.
A mixture of 10 g of 2-naphthylbenzyl ether dispersion and 22 g of calcined kaolin dispersion was added, and 4 g of zinc stearate emulsion and 5 g of an aqueous solution of 2% (2-ethylhexyl) sodium sulfosuccinate were added to obtain a coating liquid. . This coating liquid, dry coating amount wood free paper weighing 50 g / m ² was coated with a wire bar such that the 6 g / m ^2, to obtain a coated paper subjected to calendering treatment.

The coated paper obtained as described above was used as a thermal head (KLT-216-8MPD, manufactured by Kyocera Corp.).
1) and with a thermal printing experimental device having a pressure roll of 100 kg / cm ² immediately before the head, a head voltage of 24
While using a pressure roll under the conditions of V and a pulse cycle of 10 ms, printing was performed with a pulse width of 1.0, and the print density was measured with a Macbeth reflection densitometer RD-918. The color density was 1.20. In addition, the image portion that developed black with a fluorescent pen or the like was not erased at all, and the non-image portion on a white background did not develop black (fog due to the solvent). Also, the non-image area was marked with red magic ink, but the red color did not change.

Example-2 Example-2, except that the compound of Specific Example (1) which is the electron-accepting compound of Example-1 was replaced with the compound of Specific Example (2).
A coated paper was obtained in the same manner as in 1. When color was developed in the same manner as in Example-1, the color density was 1.28. In addition, the image portion that developed black with a fluorescent pen or the like was not erased at all, and the non-image portion on a white background did not develop black (fog due to the solvent). Also, the non-image area was marked with red magic ink, but the red color did not change.

Comparative Example-1 The same as Example-1 except that the compound of Specific Example (1) which is the electron-accepting compound of Example-1 was replaced with 4- (4-isopropoxyphenylsulfonyl) phenol. A coated paper was obtained. When color was developed in the same manner as in Example-1, the color density was 1.33. When a highlighter pen was applied in the same manner as in Example-1, the non-image area of the white background was colored black, and the fogging with the solvent was exhibited. When a mark was made on the non-image area with red magic ink, discoloration was observed in red and black.

Comparative Example-2 Example 1 was repeated except that the compound of the specific example (1) which was the electron accepting compound of Example-1 was replaced with bis- (3-phenyl-4-hydroxyphenyl) sulfone. A coated paper was obtained in the same manner as in. When color was developed in the same manner as in Example-1, the color density was 1.28. When a highlighter pen was applied in the same manner as in Example-1, the non-image area of the white background was colored black, and the fogging with the solvent was exhibited. When a mark was made on the non-image area with red magic ink, discoloration was observed in red and black.

[0051]

As is clear from the results of the "Examples", the recording material of the present invention has high sensitivity and is excellent in weather resistance and chemical resistance.

Claims (1)

[Claims] 1. A recording material using an electron-donating colorless dye and an electron-accepting compound, comprising at least one compound represented by the following general formula (1) as an electron-accepting compound. Recording material. General formula (1) In the formula, X and Y may be the same or different and each is a hydrogen atom, a halogen atom, a hydroxy group, a carboxyl group, an alkoxycarbonyl group, an alkyl group, an alkoxy group, an allyl group, an aryl group, an aralkyl group, or a cycloalkyl group. And R represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryloxyalkyl group.