JPH08216524A - Recording material - Google Patents

Abstract

PURPOSE: To provide a recording material excellent in storage stability. CONSTITUTION: In a recording material wherein a recording layer containing at least one electrodonating leuco dye and at least one electron acceptive compd. is provided on a support, as the electron acceptive compd., a compd. containing 4-10 phenol units each having at least one pohenolic hydroxyl group in one molecule thereof is used.

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 excellent storage stability.

[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 widely known as an electrically conductive recording paper and a thermal transfer paper. For example, British Patent No. 2140449, US Patent Nos. 4480052, 4436920, and JP-B-60.
No. 23992, JP-A Nos. 57-179836 and 60.
For details, see No. 123535, No. 60-123557 and the like.

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 (light resistance, heat resistance, chemical resistance, plastic resistance). It had some drawbacks in terms of formulation properties, etc. For example, when bisphenol A is used for a heat-sensitive recording material, there is a problem that discoloration or decoloration of an image portion occurs under dark heat.

[0004]

An object of the present invention is to provide a recording material having excellent storage stability.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording material having a recording layer containing at least one of an electron-donating colorless dye and an electron-accepting compound provided on a support as the electron-accepting compound. It has been achieved by a recording material characterized by using a compound containing 4 to 10 phenol units having at least one phenolic hydroxyl group in one molecule. Here, one phenol unit having at least one phenolic hydroxyl group is used as the electron-accepting compound.
Among the compounds containing 4 to 10 in the molecule, compounds containing 4 to 8 phenol units in the molecule are preferable, and compounds containing 4 to 6 are more preferable. The electron-accepting compound of the present invention does not include polymer compounds such as so-called novolac resins. Among the electron-accepting compounds of the present invention, compounds represented by the following general formula (I) are particularly preferable. General formula (I)

[0006]

Embedded image

R is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an aryl group, an aralkyl group or an alkoxy group, R ₁ and R ₂ are a hydrogen atom, an alkyl group, an aryl group or an alkoxy group, and a and b are The integer of 0-4 is represented, and k, l, m, and n represent the integer of 0-2.

Of these substituents, preferred are those in which R is a hydrogen atom, a hydroxyl group, R ₁ and R ₂ are hydrogen atoms, an alkyl group, and a and b are 0 and 1.

More preferably, R, R ₁ and R ₂ are hydrogen atoms, a, b, k and l are 0 and m and n are 2.
It is preferable that the substitution position of the hydroxyl group is 4-position.

Specific examples of the electron-accepting compound of the present invention include tetra (4-hydroxyphenyl) methane, 1,
2,2,3-tetra (4-hydroxyphenyl) propane, 1,4,4,7-tetra (4-hydroxyphenyl) heptane, 1,4,4,7-tetra (4-hydroxyphenyl) -3, 5-dimethylheptane, 1,3
3,5-tetra (4-hydroxyphenyl) pentane,
3,3-bis (3-methyl-4-hydroxyphenyl)
-1,5-bis (4-hydroxyphenyl) pentane,
1,3,3,5-tetra (3-methyl-4-hydroxyphenyl) pentane, 3,3-bis (3-phenyl-4)
-Hydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 3,3-bis (3-chloro-4)
-Hydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 1,5-bis (3-chloro-4)
-Hydroxyphenyl) -3,3-bis (4-hydroxyphenyl) pentane, 3,3-bis (3-fluoro-
4-hydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 1,5-bis (3-fluoro-4-hydroxyphenyl) -3,3-bis (4-hydroxyphenyl) pentane, 3, 3-bis (3,4-dihydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 1,5-bis (3,4-dihydroxyphenyl) -3,3-bis (4-hydroxyphenyl) Pentane,

1,3,3,5-tetra (3,4-dihydroxy) pentane, 3,3-bis (2,4-dihydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 1, 5-bis (2,4-dihydroxyphenyl) -3,3-bis (4-hydroxyphenyl) pentane, 3,3-bis (4-hydroxyphenyl)-
1,5-bis (3,5-dihydroxyphenyl) pentane, 3,3-bis (2,3,4-trihydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane, 3,3-bis (4-hydroxyphenyl) -1,5
-Bis (3,4,5-trihydroxyphenyl) pentane, 1,3,3,5-tetra (4-hydroxyphenyl) -2,4-dimethylpentane, 1,3,3,5-tetra (4- Examples thereof include, but are not limited to, hydroxyphenyl) -2,4-diethylpentane, 1,3,3,5-tetra (4-hydroxyphenyl) -2,4-diphenylpentane, and the like.

Examples of the electron-donating colorless dye used in the present invention include known triphenylmethanephthalide compounds, fluorane compounds, phenothiazine compounds, indolylphthalide compounds, leukoauramine compounds, rhodamine lactam compounds. Examples include various compounds such as compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, and fluorene compounds. Specific examples of the phthalides are US Reissue Patent Specification No. 23024,
US Patent Nos. 3491111 and 349111
No. 2, No. 3491116 and No. 3509174.
And specific examples of fluoran compounds are disclosed in US Pat. No. 3,624,324.
No. 107, No. 3627787, No. 3641011
No. 3,462,828, No. 3,681,390, No. 3,920,510, No. 3,959,571, and spiro dipyrans are specific examples of U.S. Pat. No. 3,971,808.
, Pyridine-based and pyrazine-based compounds are described in U.S. Pat. Nos. 3,775,424, 3,853,869, and 4,
264318 and specific examples of fluorene compounds are described in JP-A-59-199757 and JP-A-63-41183.

Specific compounds include 3- (2-methyl-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide and 3- (2-methyl). -4-Dinormalhexylaminophenyl) -3- (1-normaloctyl-2-methylindol-3-yl) -4,7-diazaphthalide,
3,3-bis (2-ethoxy-4-diethylaminophenyl) -4-azaphthalide, 3,3-bis (1-normaloctyl-2-methylindol-3-yl) -4-
Azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3 -(1-Normaloctyl-2-methylindol-3-yl) -phthalide, 3,3-bis (1-normaloctyl-2-methylindol-3-yl) -phthalide, 3- (2-methyl-4) -Diethylaminophenyl) -3- (1-normaloctyl-2-methylindol-3-yl) -phthalide, 3- (N-ethyl-N-isoamyl) -6-methyl-7-anilinofluorane, 3, 6-bis (diphenylamino) fluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3- (N-ethyl-N-
Isobutyl) -6-methyl-7-anilinofluorane and the like. The coating amount of these electron-donating colorless dyes is not particularly limited, but is preferably 0.1 to 2.0 g / m ² , and particularly preferably 0.2 to 1.5 g / m ² .

The electron-accepting compound of the present invention is used in combination with conventionally known compounds such as a phenol derivative, a salicylic acid derivative, a metal salt of an aromatic carboxylic acid, acid clay, bentonite, a novolac resin, a metal-treated novolac resin, and a metal complex. can do. Examples of these are Japanese Patent Publication No. 40-93.
09, 45-14039 and JP-A-562.
-140483, 48-51510, 57-210886, 58-87089, 59-11286, 60-76795, 61-95988, etc. Has been described.

Examples of some of these are 4-tert-butylphenol, 4-phenylphenol, 2,
2'-dihydroxybiphenyl, 2,2-bis (4-
Hydroxyphenyl) propane (bisphenol A),
4,4'-sec-butylidene diphenol, 4,4 '
-Cyclohexylidene diphenol, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxyphenyl-3 ', 4' dimethylphenyl sulfone, 4-
(4-isopropoxyphenylsulfonyl) phenol, 4,4′-dihydroxydiphenyl sulfide,
1,4-bis- (4'-hydroxycumyl) benzene,
1,3-bis- (4'-hydroxycumyl) benzene,
4,4'-thiobis (6-tert-butyl-3-methylphenol), 4,4'-dihydroxydiphenylsulfone, 4-hydroxybenzoic acid benzyl ester,
3,5-di-tert-butylsalicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl) salicylic acid, 3
-Cumyl-5-t-octylsalicylic acid, 3,5-di-
t-butylsalicylic acid, 3-phenyl-5-t-octylsalicylic acid, 3-methyl-5-α-methylbenzylsalicylic acid, 3-methyl-5-cumylsalicylic acid, 3,5
-Di-t-octylsalicylic acid, 3,5-bis (α-methylbenzyl) salicylic acid, 3-cumyl-5-phenylsalicylic acid, 5-n-octadecylsalicylic acid, 4-pentadecylsalicylic acid, 3,5-bis (α , Α-Dimethylbenzyl) salicylic acid, 3,5-bis-t-octylsalicylic acid, 4-β-dodecyloxyethoxysalicylic acid, 4-methoxy-6-dodecyloxysalicylic acid, 4
Examples include -β-phenoxyethoxysalicylic acid, 4-β-p-ethylphenoxyethoxysalicylic acid, 4-β-p-methoxyphenoxyethoxysalicylic acid and the like, and metal salts thereof.

These electron accepting compounds are preferably used in a proportion of 10 to 100% by weight based on the electron accepting compound of the present invention. Two or more kinds of the above-mentioned electron-accepting compounds of the present invention or those of the present invention may be used in combination. The weight ratio of the electron-donating colorless dye to the electron-accepting compound of the present invention is preferably 1:10 to 1: 1 and more preferably 1: 5.
Especially preferred is between 3 and 2: 3.

An electron-donating colorless dye used in the present invention,
The electron-accepting compound can be used in the form of solid dispersion, emulsion dispersion, or microencapsulation. When the recording material of the present invention is used as a heat-sensitive recording material, it is preferable to use an electron-donating colorless dye in a microencapsulated state, and an electron-accepting compound in a solid dispersion or an emulsion dispersion. Solid dispersion, emulsion dispersion, and microencapsulation can be performed by known methods.

In the recording material of the present invention, safety against light
An ultraviolet absorber may be added to improve the quality. purple
As external radiation absorbers, cinnamic acid derivatives and benzophenone derivatives
Conductors, benzotriazolylphenol derivatives, etc.
Can be Specifically, α-cyano-β-phenylcinnamic acid
Chill, o-benzotriazolephenol, o-benzo
Triazole-p-chlorophenol, o-benzotri
Azole-2,4-di-t-butylphenol, o-be
Nzotriazole-2,4-di-t-octylpheno
There are such as Le. As a hindered phenol compound,
At least one of the 2- or 6-positions is branched alkyl
Group-substituted phenol derivatives are preferred. These purple
The external absorbent is solid dispersion, emulsion dispersion or microcapsule.
It can be used after being converted into a package. The amount of UV absorber used
Then, 0.05-1.0 g / m ²Is preferred, especially
0.1-0.4g / m²Is preferred.

As the binder used in the recording material of the present invention, known water-soluble polymer compounds and latexes can be used. As the water-soluble polymer compound, methyl cellulose, carboxymethyl cellulose, hydroxytyl cellulose, starches, gelatin, gum arabic, casein, styrene-maleic anhydride copolymer hydrolyzate, ethylene-maleic anhydride copolymer hydrolyzate , Polyvinyl alcohol, polyacrylamide and the like and modified products thereof, and the latexes include styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion and the like. The amount of these used is preferably 0.4 to 5 g / m ² , more preferably 0.8
˜1.6 g / m ² is preferred.

As the pigment that can be used in the recording material of the present invention, known pigments, whether organic or inorganic, can be used. Specifically, kaolin, calcined kaolin, talc,
Wax stone, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, zinc oxide, lithopone, amorphous silica, colloidal silica, calcined stone ko, silica, magnesium carbonate, titanium oxide, alumina, barium carbonate, barium sulfate, Mica, micro balloon, urea-
Formalin filler, polyester particles, cellulose filler and the like can be mentioned.

In the recording material of the present invention, known waxes, antistatic agents, antifoaming agents, conductive agents, and
Various additives such as fluorescent dyes, surfactants, and ultraviolet absorber precursors can be used.

In the recording material of the present invention, a protective layer may be provided on the surface of the recording layer, if necessary. Two or more protective layers may be laminated if necessary. 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, isobutylene-maleic anhydride copolymer hydrolyzate, polyacrylamide derivative, polyvinylpyrrolidone, sodium polystyrene sulfonate, sodium alginate Water-soluble polymer compounds such as styrene-butadiene rubber latex, acrylonitrile-butadiene rubber latex,
Latexes such as methyl acrylate-butadiene rubber latex and vinyl acetate emulsion are used. The water-soluble polymer compound in the protective layer can be crosslinked to further improve the storage stability, and a known crosslinking agent can be used as the crosslinking agent. Specifically, water-soluble initial condensates such as N-methylol urea, N-methylol melamine, and urea-formalin, dialdehyde compounds such as glyoxal and glutaraldehyde, inorganic cross-linking agents such as boric acid and borax, polyamide epichlorohydrin, etc. Can be mentioned. Further, known pigments, metal soaps, waxes, surfactants and the like can be used in the protective layer. The coating amount of the protective layer is preferably 0.2 to 5 g / m ² , more preferably 0.
5 to ² g / m ² is preferable. The film thickness is 0.2 to 5
μm is preferable, and 0.5 to 2 μm is particularly preferable.

As the support that can be used in the recording material of the present invention, acid paper, neutral paper, coated paper, plastic film laminated paper, synthetic paper, plastic film and the like can be used. Further, these supports may be provided with a known undercoat layer. This undercoat layer can be provided in the same manner as the protective layer.

In order to correct the curl balance of the support or to improve the chemical resistance from the back side, a back coat layer may be provided, and the back side may be combined with a release paper via an adhesive layer to label the label. You may take the form of. This back coat layer can be provided in the same manner as the protective layer.

The recording material of the present invention can be used as a heat-sensitive recording material, and the heat-sensitive recording material is disclosed in JP-B-59-53193 and JP-A-59-197463.
For example, it is described in detail in JP-A No. 62-114989.

When the electron-accepting compound of the present invention is used as a heat-sensitive recording material, a known sensitizer can be contained in the heat-sensitive recording layer in order to improve the thermal response. Examples of the sensitizer 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, 62-13267.
4, gazette 63-151478, gazette 63-23.
It is described in detail in Japanese Patent Publication No. 5961 and the like. The amount of these used is preferably 1 to 10 g / m ² , and more preferably ² to 4 g / m ² .

The electron-accepting compound of the present invention can be used in a heat-sensitive recording material, particularly a multicolor heat-sensitive recording material. Regarding this multicolor thermosensitive recording material (photosensitive thermosensitive recording material),
JP-A-4-135787, JP-A-4-144784, JP-A-4-144785, and JP-A-4-194842.
Japanese Patent Publication No. 4-247447 and Japanese Patent Publication No. 4-24744.
No. 8 and No. 4-340540, No. 4-3405.
No. 41, No. 5-34860 and the like. Specifically, it can be obtained by laminating thermosensitive recording layers that develop different hues. The layer structure is not particularly limited, but in particular, a thermosensitive recording layer 2 in which two types of diazonium salt compounds having different photosensitizing wavelengths are combined with respective diazonium salt compounds to combine with a coupler capable of developing a different hue A multicolor heat-sensitive recording material in which a layer and a heat-sensitive recording layer in which an electron-donating colorless dye and an electron-accepting compound are combined are laminated is preferable. That is, a first heat-sensitive recording layer containing an electron-donating colorless dye and an electron-accepting compound on a support, a diazonium salt compound having a maximum absorption wavelength of 360 nm ± 20 nm, and a color reaction by reacting with the diazonium salt compound. A second heat-sensitive recording layer containing a coupler, and a third heat-sensitive recording layer containing a diazonium salt compound having a maximum absorption wavelength of 400 ± 20 nm and a coupler that reacts with the diazonium salt compound to produce a color when heated. is there. In this example, full-color image recording is possible by selecting the hues of the heat-sensitive recording layers to be the three primary colors in subtractive color mixing, yellow, magenta, and cyan.

In the recording method of this multicolor heat-sensitive recording material, first, the third heat-sensitive recording layer is heated to cause the diazonium salt and the coupler contained in the layer to develop color. Next 400 ± 20 nm
Is irradiated to decompose the unreacted diazonium salt compound contained in the third thermosensitive recording layer, and then the second thermosensitive recording layer is provided with sufficient heat to develop a color. The colored diazonium salt compound and the coupler are colored.
At this time, the third thermosensitive recording layer is also heated strongly at the same time,
Since the diazonium salt compound has already been decomposed and the coloring ability has been lost, it does not develop color. Further 360 ± 20 nm
Is irradiated to decompose the diazonium salt compound contained in the second thermosensitive recording layer, and finally, sufficient heat for coloring the first thermosensitive recording layer is applied to cause color development. At this time, the third,
The second thermosensitive recording layer is also heated strongly at the same time, but the diazonium salt compound is already decomposed and the coloring ability is lost, so that no coloring occurs.

When the recording material of the present invention is a multicolor thermosensitive recording material, an intermediate layer may be provided in order to prevent color mixing between the thermosensitive recording layers. This intermediate layer is made of a water-soluble polymer compound such as gelatin, phthalated gelatin, polyvinyl alcohol and polyvinylpyrrolidone, and may contain various additives as appropriate. The coating amount is preferably from 2 to 10 g / m ^2, more preferably 4-5 g / m ^2. The film thickness is preferably 2 to 10 μm, and particularly preferably 4 to 5 μm.

[0030]

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 Preparation of recording material [Preparation of electron-donating dye precursor capsule liquid] 3- (2-
3.0 parts of methyl-4-dimethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide (electron-donating dye precursor) are dissolved in 20 parts of ethyl acetate, Furthermore, 20 parts of alkylnaphthalene (KMC-210, manufactured by Kureha Chemical Industry Co., Ltd.), which is a high boiling point solvent, was added and uniformly mixed. 20 parts of xylylene diisocyanate / trimethylol propane 3/1 adduct (75 wt% ethyl acetate solution) (Takenate D-110N (manufactured by Takeda Chemical Industries, Ltd.)) was added to the obtained mixed liquid as a capsule wall material. Added and stirred uniformly.

Separately, polyvinyl alcohol (polymerization degree: 17
00, saponification degree 88%) 54% 6% aqueous solution was prepared, and the above-mentioned electron-donating dye precursor was added thereto, followed by emulsification and dispersion with a homogenizer. 68 parts of water was added to the obtained emulsion for homogenization, the temperature was raised to 50 ° C. with stirring, and the encapsulation reaction was carried out for 3 hours to obtain the target capsule solution.
The average particle size of the capsule was 1.6 μm.

[Preparation of Electron-Accepting Compound Dispersion] After adding 30 parts of 1,3,3,5-tetra (4-hydroxyphenyl) pentane as an electron-accepting compound to 150 parts of a 4% aqueous solution of polyvinyl alcohol. , Ball mill 2
A dispersion was prepared by dispersing for 4 hours. The average particle size of the electron-accepting compound in the obtained dispersion was 1.2 μm. [Preparation of coating liquid] The above-mentioned electron-donating dye precursor capsule liquid and electron-accepting compound dispersion liquid are used as electron-donating dye precursor /
The electron-accepting compound was mixed at a molar ratio of 1/15 to prepare a target coating solution. [Coating] The above-mentioned coating liquid was coated on a polyethylene terephthalate support having a thickness of 75 μm with a Meyer bar and dried to obtain a desired heat-sensitive recording material.

Example 2 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 1, was converted into 3,3-bis (4-hydroxyphenyl) -1,3-bis. (3,4
A thermosensitive recording material was obtained in the same manner as in Example 1 except that -dihydroxyphenyl) pentane was used instead. Example 3 The electron-accepting compound of Example 1, 1,3,3,5-tetra (4-hydroxyphenyl) pentane was converted into 3,3-bis (3-methyl-4-hydroxyphenyl) -1,5-
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that bis (4-hydroxyphenyl) pentane was used instead. Example 4

1, which is the electron-accepting compound of Example 1.
Implemented except that 3,3,5-tetra (4-hydroxyphenyl) pentane was replaced with 3,3-bis (3-chloro-4-hydroxyphenyl) -1,5-bis (4-hydroxyphenyl) pentane A thermal recording material was obtained in the same manner as in Example 1. Example 5 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 1, was converted into 1,3,3.
3,5-tetra (4-hydroxyphenyl) -2,3-
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that dimethylpentane was used.

Comparative Example 1 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 1, was added to 1,1,1.
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that tris (4-hydroxyphenyl) ethane was used. Comparative Example 2 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 1, was mixed with α, α,
A heat-sensitive recording material was obtained in the same manner as in Example 1 except that α′-tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene was used.

Example 6 2-anilino-3-methyl-6-N-ethyl-N-tetrahydrofurfurylaminofluorane as an electron-donating colorless dye and 1,3,3,5- as an electron-accepting compound
Tetra (4-hydroxyphenyl) pentane, oxalic acid di (p-methylbenzyl) ester as a sensitizer, 20 g each were dispersed in a ball mill for 24 hours together with 100 g of a 5% polyvinyl alcohol (Kuraray PVA-105) aqueous solution, and the average particle size To 1.5 μm or less to obtain each dispersion. Further, 80 g of calcium carbonate was dispersed with 160 g of a 0.5% sodium hexametaphosphate solution by a homogenizer to obtain a pigment dispersion liquid. 5 g of the electron-donating colorless dye dispersion liquid, 10 g of the electron-accepting compound dispersion liquid, 3 g of the thiourea compound dispersion liquid, 10 g of the oxalic acid di (p-methylbenzyl) ester dispersion liquid, and 10 g of calcium carbonate were prepared. The dispersion was mixed at a ratio of 5 g, and further 21
% Zinc stearate emulsion was added to obtain a heat-sensitive coating liquid. This thermosensitive coloring layer coating solution was applied to a high-quality paper having a basis weight of 50 g / m ² using a wire bar so that the dry weight of the coating layer was 5
It was coated so as to be g / m ² and dried at 50 ° C. for 1 minute to obtain a heat-sensitive recording material.

Example 7 The electron-accepting compound of Example 6, 1,3,3,5-tetra (4-hydroxyphenyl) pentane was replaced with 3,3-bis (4-hydroxyphenyl) -1,3-bis. (3,4
A thermosensitive recording material was obtained in the same manner as in Example 6 except that -dihydroxyphenyl) pentane was used instead. Example 8 1,3,3,5-Tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 6, was converted into 3,3-bis (3-methyl-4-hydroxyphenyl) -1,5-
A heat-sensitive recording material was obtained in the same manner as in Example 6 except that bis (4-hydroxyphenyl) pentane was used instead.

Example 9 3,3-bis (3-chloro-4-hydroxyphenyl) -1 was prepared by converting 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 6, into 3,3-bis (3-chloro-4-hydroxyphenyl) -1. , 5-
A heat-sensitive recording material was obtained in the same manner as in Example 6 except that bis (4-hydroxyphenyl) pentane was used instead. Example 10 1,3,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 6, is converted into 1,3,3.
3,5-tetra (4-hydroxyphenyl) -2,3-
A heat-sensitive recording material was obtained in the same manner as in Example 6 except that dimethylpentane was used instead.

Comparative Example 3 1,1,3,5-tetra (4-hydroxyphenyl) pentane, which is the electron-accepting compound of Example 6, was added to 1,1,1.
A thermosensitive recording material was obtained in the same manner as in Example 6 except that tris (4-hydroxyphenyl) ethane was used. Comparative Example 4 The electron-accepting compound of Example 6, 1,3,3,5-tetra (4-hydroxyphenyl) pentane was converted into α, α,
A thermosensitive recording material was obtained in the same manner as in Example 6 except that α′-tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene was used instead.

(Color density) The color density was printed with a Kyocera printing tester and the color density was measured with a Macbeth densitometer. The higher this value, the higher the sensitivity of the thermal recording paper. (Evaluation of heat resistance of image area) Printed recording material is Macbeth R
After measuring the color density according to D-918, the color density was stored in an oven at 80 ° C. for 3 days, and the density of the printed portion after storage was measured again. After the measurement, the coloring density residual ratio shown in the following formula was measured. Color development density residual rate (%) = (density after storage in 80 ° C. oven for 3 days) / (density before storage) × 100 (The larger the value, the better the heat resistance.)

(Lightfastness test of image area) For an image (color image) obtained by printing, a xenon fade meter (FAL
-25AX-HC type, manufactured by Suga Test Instruments Co., Ltd.). The time of light irradiation was 24 hours. The image density D after light irradiation and the image density D ₀ before light irradiation were measured with a Macbeth reflection densitometer. The light fastness is shown by using the residual rate of image after light irradiation = (D / D ₀ ) × 100% as a guide. The higher the residual rate, the better the light fastness. (Chemical resistance test of non-image area and image area) The chemical resistance test was conducted by impregnating filter paper with ethanol and plasticizer (dioctyl phthalate), and overlaying it on the colored surface of the recording paper obtained by the above method. The degree of fog in the area and the decolorization (discoloration) of the colored area were evaluated. The above evaluation results are shown in Tables 1 to 3.
Shown in

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

According to the present invention, a recording material having good heat resistance, light resistance and solvent resistance is provided.

Claims (2)

[Claims] 1. A recording material comprising a support and a recording layer containing at least one of an electron-donating colorless dye and an electron-accepting compound, wherein at least 1 is used as the electron-accepting compound.
A recording material comprising a compound containing 4 to 10 phenol units having one phenolic hydroxyl group in one molecule. 2. The recording material according to claim 1, wherein the electron-accepting compound is a compound represented by the following general formula (I). General formula (I) R is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an aryl group, an aralkyl group or an alkoxy group, R ₁ and R ₂ are a hydrogen atom, an alkyl group, an aryl group or an alkoxy group, and a and b are 0 to 4 The integers of k, l, m
And n represent the integer of 0-2.