JPH06219045A - Recording material - Google Patents

Abstract

PURPOSE:To provide a recording material imparting high developed color density and good in the light fastness of its color forming part. CONSTITUTION:In a recording material using an electron donating leuco dye and an electron acceptive compd., as the electron donating leuco dye, a 2- diphenylamino-3-alkoxy-6-aminofluorane compd. or a 2-diphenylamino-3- alkylthio-6-aminofluorane compd. is contained.

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 improved color forming property and light fastness of a color forming body.

[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 2140449 and US Patent 44
80052, 4436920, Japanese Patent Publication No. 60-2399.
2, JP-A-57-179836 and 60-12355.
6 and 60-123557.

As a recording material, research has recently been earnestly conducted to improve characteristics such as color density and light resistance of a color developing body. Among them, attempts have been made to improve an electron-donating colorless dye, and various studies have been conducted so far on 2,6-diaminofluorane compounds capable of producing black color independently. Among them, 2-anilino-6-diaminofluorane compounds having an alkoxy group at the 3-position, for example, have been disclosed in order to improve the color developability (Japanese Patent Laid-Open Publication No. Sho 5).
Nos. 9-62666, 59-135254, etc.) are not preferable for practical use because they cause fog and the color hue is bluish. In addition, in order to improve the light resistance of the color developing body,
Those in which a substituent is introduced into the 2-position anilino group are disclosed (JP-A-57-105155 and JP-A-61-1828).
6, 63-192777, JP-A-1-150574, etc.) has not achieved a significant improvement in light resistance, and has the drawback of fading while discoloring. Further, compounds in which the 2-position is a diphenylamino group are also disclosed (JP-A-57-205449), but these compounds have a low color density and are not preferable in practice.

The present inventors have conducted extensive studies to solve these problems, and as a result, a 2-diphenylamino-6-diaminofluorane compound having an alkoxy group or an alkylthio group at the 3-position develops black color alone. It has been found that both the color developing property and the light resistance are improved as compared with the conventional 2,6-diaminofluorane compound.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording material having improved color forming property and light fastness of a color forming body.

[0006]

[Means for Solving the Problems] The above-mentioned problem is solved by using a 2-diphenylamino-3-alkoxy-6-aminofluorane compound or a 2-diphenylamino-3-alkylthio-6-aminofluorane compound as an electron-donating colorless dye. It was achieved by a recording material characterized in that
Among the fluoran compounds according to the present invention, those represented by the following general formula (1) are preferable. General formula (1)

[0007]

[Chemical 1]

In the formula, R ¹ and R ² may be the same or different and each represents an alkyl group, an aralkyl group or an aryl group. R ³ represents an alkyl group having 1 to 4 carbon atoms. R ⁴ ,
R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ may be the same or different and each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms,
It represents an alkoxy group having 1 to 4 carbon atoms or a halogen atom. X represents an oxygen atom or a sulfur atom.

In the above general formula (1), R¹, R²so
Of the substituents represented, an alkyl group having 1 to 10 carbon atoms,
Aralkyl groups having 7 to 12 carbon atoms and 6 to 1 carbon atoms
An aryl group of 2 is preferable, and an aryl group of 1 to 6 carbon atoms is particularly preferable.
Kill group and aryl group having 6 to 10 carbon atoms are preferred.
Yes. These substituents are further alkyl having 1 to 4 carbons.
Group, alkoxy group having 1 to 2 carbon atoms, halogen atom
It may be replaced. R ¹, R²As a concrete example of
Is a methyl group, ethyl group, n-propyl group, isopropyl group
Group, n-butyl group, isobutyl group, n-pentyl group,
Isoamyl group, n-hexyl group, phenyl group, methyl group
Phenyl (tolyl) group, ethylphenyl group, propylphene
Nyl group, butylphenyl group, methoxyphenyl group, eth
Xyphenyl group, chlorophenyl group, benzyl group, etc.
Can be mentioned.

In the above general formula (1), among the substituents represented by R ³ , a methyl group, an ethyl group, a propyl group and a butyl group are preferable, and a methyl group and an ethyl group are particularly preferable.

In the above general formula (1), R ⁴ , R ⁵ ,
R ⁶ , R ⁷ , R ⁸ and R ⁹ are hydrogen atoms among the substituents,
Methyl group, ethyl group, propyl group, butyl group, methoxy group, ethoxy group, propoxy group, butoxy group, fluorine atom, chlorine atom, bromine atom, iodine atom and the like,
A methyl group, an ethyl group, a methoxy group, an ethoxy group and a chlorine atom are particularly preferable.

Next, specific examples of the fluorane derivative according to the present invention will be shown, but the present invention is not limited thereto.

2-diphenylamino-3-methoxy-6
-Dimethylaminofluorane, 2-diphenylamino-
3-methoxy-6-diethylaminofluorane, 2-di-p-tolylamino-3-methoxy-6-diethylaminofluorane, 2-di-m-tolylamino-3-methoxy-6-diethylaminofluorane, 2-di- o-tolylamino-3-methoxy-6-diethylaminofluorane, 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (m
-Methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (o-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (p-ethylphenyl) amino-3- Methoxy-6-diethylaminofluorane, 2-bis (p
-Ethoxyphenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (pn-propoxyphenyl) amino-3-methoxy-6-diethylaminofluorane,

2-bis (pn-butoxyphenyl) amino-3-methoxy-6-diethylaminofluorane,
2-bis (p-chlorophenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (m-chlorophenyl) amino-3-methoxy-6-diethylaminofluorane, 2-bis (o-chlorophenyl) amino- 3-methoxy-6-diethylaminofluorane, 2-
Diphenylamino-3-methoxy-6-N-ethyl-N
-P-tolylaminofluorane, 2-di-p-tolylamino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane, 2-di-m-tolylamino-3-methoxy-6-N -Ethyl-Np-tolylaminofluorane, 2-di-o-tolylamino-3-methoxy-6-
N-ethyl-Np-tolylaminofluorane, 2-bis (p-methoxyphenyl) amino-3-methoxy-6
-N-ethyl-Np-tolylaminofluorane, 2-
Bis (m-methoxyphenyl) amino-3-methoxy-
6-N-ethyl-Np-tolylaminofluorane,

2-bis (o-methoxyphenyl) amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane, 2-bis (p-ethylphenyl) amino-3-methoxy-6- N-ethyl-Np-tolylaminofluorane, 2-bis (p-ethoxyphenyl) amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane, 2-bis (pn) -Propoxyphenyl) amino-3-methoxy-6-N-ethyl-Np-
Trilylaminofluorane, 2-bis (pn-butoxyphenyl) amino-3-methoxy-6-N-ethyl-N
-P-tolylaminofluorane, 2-bis (p-chlorophenyl) amino-3-methoxy-6-N-ethyl-N
-P-tolylaminofluorane, 2-bis (m-chlorophenyl) amino-3-methoxy-6-N-ethyl-N
-P-tolylaminofluorane, 2-bis (o-chlorophenyl) amino-3-methoxy-6-N-ethyl-N
-P-tolylaminofluorane, 2-diphenylamino-3-methoxy-6-di-n-butylaminofluorane,

2-diphenylamino-3-methoxy-6
-N-ethyl-N-isoamylaminofluorane, 2-
Di-p-tolylamino-3-methoxy-6-di-n-butylaminofluorane, 2-di-m-tolylamino-3
-Methoxy-6-di-n-hexylaminofluorane,
2-di-o-tolylamino-3-methoxy-6-N-ethyl-N- (3-ethoxypropyl) aminofluorane, 2-bis (p-methoxyphenyl) amino-3-methoxy-6-N-ethyl -N- (2-methoxyethyl)
Aminofluorane, 2-bis (m-methoxyphenyl)
Amino-3-methoxy-6-N-ethyl-N-isobutylaminofluorane, 2-bis (o-methoxyphenyl) amino-3-methoxy-6-N-ethyl-N-isopropylaminofluorane, 2-bis (P-Ethylphenyl) amino-3-methoxy-6-N-methyl-Nn
-Butylaminofluorane, 2-bis (p-ethoxyphenyl) amino-3-methoxy-6-N-ethyl-N-
o-tolylaminofluorane, 2-bis (pn-propoxyphenyl) amino-3-methoxy-6-N-ethyl-N-phenylaminofluorane,

2-bis (pn-butoxyphenyl) amino-3-methoxy-6-N-ethyl-N- (p-methoxyphenyl) aminofluorane, 2-bis (p-chlorophenyl) amino-3 -Methoxy-6-N-ethyl-
N- (p-chlorophenyl) aminofluorane, 2-bis (m-chlorophenyl) amino-3-methoxy-6-
Di-n-pentylaminofluorane, 2-bis (o-chlorophenyl) amino-3-methoxy-6-di-n-propylaminofluorane, 2-bis (1,3-dimethylphenyl) amino-3-methoxy -6-diethylaminofluorane, 2-bis (3,4-dimethylphenyl) amino-3-methoxy-6-diethylaminofluorane,
2-bis (3,4-dimethylphenyl) amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane, 2-bis (2,3-dimethylphenyl) amino-
3-Methoxy-6-diethylaminofluorane, 2-bis (2,4-dimethoxyphenyl) amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane, 2-bis (3,4- Methylenedioxyphenyl) amino-3-methoxy-6-di-n-butylaminofluorane, 2-Np-tolyl-N-phenylamino-3-
Methoxy-6-diethylaminofluorane,

2-N-o-tolyl-N-phenylamino-3-methoxy-6-diethylaminofluorane, 2-
N- (p-methoxyphenyl) -N-phenylamino-
3-methoxy-6-diethylaminofluorane, 2-N
-(O-Methoxyphenyl) -N-phenylamino-3
-Methoxy-6-diethylaminofluorane, 2-N-
(P-Chlorophenyl) -N-phenylamino-3-methoxy-6-diethylaminofluorane, 2-N- (o
-Chlorophenyl) -N-phenylamino-3-methoxy-6-diethylaminofluorane, 2-Np-tolyl-Np-methoxyphenylamino-3-methoxy-
6-N-ethyl-N-ethoxypropylaminofluorane, 2-Np-tolyl-N-o-methoxyphenylamino-3-methoxy-6-N-ethyl-N- (3-ethoxypropyl) aminofluor Oran, 2-N-o-tolyl-N-o-methoxyphenylamino-3-methoxy-6
-N-ethyl-N-isoamylaminofluorane, 2-
N-o-tolyl-Np-methoxyphenylamino-3
-Methoxy-6-N-ethyl-N-isobutylaminofluorane, 2-N-o-chloro-N-p-methoxyphenylamino-3-methoxy-6-N-ethyl-N-p-
Trilylaminofluorane, 2-N-o-chloro-N-p
-Methylphenylamino-3-methoxy-6-N-ethyl-N-benzylaminofluorane,

2-diphenylamino-3-ethoxy-6
-Dimethylaminofluorane, 2-diphenylamino-
3-ethoxy-6-diethylaminofluorane, 2-di-p-tolylamino-3-ethoxy-6-diethylaminofluorane, 2-di-m-tolylamino-3-n-propoxy-6-diethylaminofluorane, 2- The o
-Tolylamino-3-ethoxy-6-diethylaminofluorane, 2-bis (p-methoxyphenyl) amino-
3-Ethoxy-6-diethylaminofluorane, 2-bis (m-methoxyphenyl) amino-3-isopropoxy-6-diethylaminofluorane, 2-bis (o-methoxyphenyl) amino-3-methoxy-6-diethylamino Fluorane, 2-bis (p-ethylphenyl) amino-3-n-propoxy-6-diethylaminofluorane, 2-bis (p-chlorophenyl) amino-3-ethoxy-6-diethylaminofluorane, 2-diphenylamino -3-ethoxy-6-N-ethyl-Np-tolylaminofluorane,

2-di-p-tolylamino-3-ethoxy-6-N-ethyl-Np-tolylaminofluorane,
2-bis (p-methoxyphenyl) amino-3-ethoxy-6-N-ethyl-Np-tolylaminofluorane, 2-bis (o-methoxyphenyl) amino-3-n
-Butoxy-6-N-ethyl-N-p-tolylaminofluorane, 2-bis (p-chlorophenyl) amino-3
-Ethoxy-6-N-ethyl-N-p-tolylaminofluorane, 2-bis (o-chlorophenyl) amino-3
-Ethoxy-6-N-ethyl-Np-tolylaminofluorane, 2-diphenylamino-3-methylthio-6
-Diethylaminofluorane, 2-diphenylamino-
3-Methylthio-6-N-ethyl-N-p-tolylaminofluorane, 2-di-p-tolylamino-3-methylthio-6-diethylaminofluorane, 2-di-p-tolylamino-3-methoxy-6 -N-ethyl-N-p-
Trilylaminofluorane,

2-di-o-tolylamino-3-methylthio-6-diethylaminofluorane, 2-di-o-tolylamino-3-methylthio-6-N-ethyl-Np-
Trilylaminofluorane, 2-bis (p-methoxyphenyl) amino-3-methylthio-diethylaminofluorane, 2-bis (p-methoxyphenyl) amino-3-
Methylthio-6-N-ethyl-Np-tolylaminofluorane, 2-bis (o-methoxyphenyl) amino-
3-methylthio-6-diethylaminofluorane, 2-
Bis (o-methoxyphenyl) amino-3-methylthio-6-N-ethyl-Np-tolylaminofluorane,
2-bis (p-chlorophenyl) amino-3-methylthio-6-diethylaminofluorane, 2-bis (p-chlorophenyl) amino-3-methylthio-6-N-ethyl-Np-tolylaminofluorane, 2 -Diphenylamino-3-ethylthio-6-diethylaminofluorane, 2-diphenylamino-3-ethylthio-6-N-
Ethyl-Np-tolylaminofluorane, 2-di-p
-Tolylamino-3-ethylthio-6-diethylaminofluorane,

2-di-p-tolylamino-3-ethoxy-6-N-ethyl-Np-tolylaminofluorane,
2-di-o-tolylamino-3-n-propylthio-6
-Diethylaminofluorane, 2-di-o-tolylamino-3-n-propylthio-6-N-ethyl-Np-
Trilylaminofluorane, 2-bis (p-methoxyphenyl) amino-3-n-butylthio-diethylaminofluorane, 2-bis (p-methoxyphenyl) amino-
3-n-butylthio-6-N-ethyl-Np-tolylaminofluorane, 2-bis (o-methoxyphenyl)
Amino-3-ethylthio-6-diethylaminofluorane, 2-bis (o-methoxyphenyl) amino-3-ethylthio-6-N-ethyl-Np-tolylaminofluorane, 2-bis (p-chlorophenyl) Amino-3-
Ethylthio-6-diethylaminofluorane, 2-bis (p-chlorophenyl) amino-3-ethylthio-6-
N-ethyl-Np-tolylaminofluorane etc. are mentioned.

The electron-donating colorless dye according to the present invention is a conventionally known triphenylmethanephthalide compound, fluorane compound, phenothiazine compound, indolylphthalide compound, leucoolamine compound, rhodaminelactam compound. , Triphenylmethane-based compounds, triazene-based compounds, spiropyran-based compounds, fluorene-based compounds and the like. Specific examples of the phthalides include US Reissue Patent Specification No. 23,024, US Patent Specification Nos. 3,491,111, and 3,491.
112, 3,491,116 and 3,5
09,174, and specific examples of fluoranes are U.S. Pat. Nos. 3,624,107 and 3,627,787.
No. 3,641,011, No. 3,462,82
No. 8, No. 3,681,390, No. 3,920,5
No. 10, No. 3,959,571, specific examples of spirodipyrans are U.S. Pat. No. 3,971,808, pyridine compounds and pyrazine compounds are U.S. Pat. No. 3,775,424, No. 3,853,869, No. 4,246,318, and specific examples of fluorene compounds are described in JP-A-63-94878.

Examples of the electron-accepting compound used in the recording material of the present invention include phenol derivatives, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolak resins, metal-treated novolac resins and metal complexes. To be Examples of these are Japanese Patent Publication No. 40-930.
9, JP-B-45-14039, JP-A-52-140.
483, JP-A-48-51510, JP-A-57-2.
10886, JP-A-58-87089, JP-A-59
-11286, JP-A-60-176795, JP-A-61-95988 and the like.

Specific examples of the electron-accepting compound include:
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-dihydroxyphenyl) -2-phenylpropane, 3,5-
Zinc bis (α-methylbenzyl) salicylate, 3,5-
Zinc bis (α, α-dimethylbenzyl) salicylate,
Zinc 3,5-bis (α, α-dimethylbenzyl) -6-methylsalicylate, zinc 3,5-di-t-octylsalicylate, zinc 4- [2- (4-methoxyphenoxy) ethoxy] salicylate, etc. Can be given.

When the recording material of the present invention is used as a pressure sensitive paper, US Pat. Nos. 2,505,470 and 2,505,505.
No. 471, No. 2,505,489, No. 2,548,3
No. 66, No. 2,712,507, No. 2,730,45
No. 6, No. 2,730,457, No. 3,103,404
Various forms can be adopted as described in the prior patents such as No. 3,418,250, and No. 4,010,038. 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 for producing capsules, a method utilizing coacervation of hydrophilic colloid sol described in US Pat. Nos. 2,800,457 and 2,800,458, and British Patent 867,797, 950,44
No. 3, 989,264, 1,091,076 and the like, or the interfacial polymerization method or US Pat.
There is a method described in No. 3,404.

Generally, an electron-donating colorless dye is used alone or in a mixture, and a solvent (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, chlorinated paraffin, etc., synthetic oil, cotton oil,
A coloring agent sheet by dissolving it in vegetable oil such as castor oil, animal oil, mineral oil, or a mixture thereof, including it in microcapsules, and applying it to paper, woodfree paper, plastic sheet, resin coated paper, etc. Get

The electron-donating colorless dye according to the present invention has a characteristic that it is more easily dissolved in the solvent used for the above-mentioned microencapsulation, as compared with the conventionally known electron-donating colorless dye. Therefore, the density of the electron-donating colorless dye can be increased, and the color density can be improved.

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 a 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 amounts of the electron-donating colorless dye and the electron-accepting compound used depend 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.

When it is used for thermal paper, it is disclosed in JP-A-62-1.
44,989, JP-A-1-87291, and the like. Specifically, the electron-donating colorless dye and the electron-accepting compound are 10 μm in the dispersion medium.
Hereinafter, it is preferably used by pulverizing and dispersing to a particle size of 3 μm or less. As the dispersion medium, a water-soluble polymer aqueous solution having a concentration of about 0.5 to 10% is generally used, and dispersion is performed by a ball mill,
It is carried out by using a sand mill, a horizontal sand mill, an attritor, a colloidal mill or the like. The ratio of the electron-donating colorless dye and the electron-accepting compound used is preferably 1:10 to 1: 1 by weight, more preferably 1: 5 to 2: 3.

At this time, a heat-fusible substance may be contained in the heat-sensitive color forming layer in order to improve the heat 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 and JP-A-5-57989.
8-87094, 61-58789, 62-1
09681, 62-2132674, 63-15
No. 1478, No. 63-235961, JP-A 2-18
No. 4489 and No. 2-215585. 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 of these used and the electron-accepting compound are added in a weight ratio of 20% to 300%, and particularly preferably 40% to 150%.

If necessary, additives may be added to the coating solution thus obtained in order to satisfy various requirements. As an example of the additive, in order to prevent contamination of the recording head at the time of recording, an oil-absorbing substance such as an inorganic pigment or polyurea filler is dispersed in the binder to further improve the releasability of the head. Therefore, fatty acids and metal soaps are added. So in general,
In addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, heat-fusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, defoamers, conductive agents, fluorescent dyes, surfactants Additives such as are coated on the support to form the recording material. Further, a protective layer may be provided on the surface of the thermosensitive recording layer, if necessary.

Usually, the electron-donating colorless dye and the electron-accepting compound are dispersed in a binder and coated. 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-anhydrous. Examples thereof include maleic salicylic acid copolymer, polyacrylic acid, polyacrylic acid amide, methylol-modified polyacrylamide, starch derivative, casein, gelatin and the like. Further, a water-proofing agent may be added to these binders for the purpose of imparting water resistance, or an emulsion of a hydrophobic polymer, specifically, a styrene-butadiene rubber latex, an acrylic resin emulsion or the like may be added.

The resulting 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.

[0038]

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

Example 1 (1) Preparation of Capsule Sheet Containing Electron Donating Colorless Dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (VERSA, TL500 manufactured by National Starch Co., Ltd.) is dissolved in 95 parts of water. . An aqueous sodium hydroxide solution was added to this to adjust the pH to 4.0. On the other hand, 2-bis (p-methoxyphenyl) amino-3-, which is an electron-donating colorless dye
Emulsification having 100 parts of diisopropylnaphthalene in which 6.8% of methoxy-6-diethylaminofluorane was dissolved in 100 parts of a 5% aqueous solution of a partial sodium salt of polyvinylbenzenesulfonic acid and having a particle size of 4.0 μm. A liquid was obtained. Separately, 6 parts of melamine, 11 parts of 37% aqueous formaldehyde solution, and 30 parts of water were heated and stirred at 60 ° C. to obtain a transparent aqueous solution of melamine formaldehyde prepolymer. This aqueous solution was mixed with the above emulsion. While stirring, adjust the pH to 6.0 with an aqueous solution of phosphoric acid and adjust the liquid temperature to 6
The temperature was raised to 5 ° C and stirring was continued for 6 hours. The capsule solution was cooled to room temperature and adjusted to pH = 9.0 with an aqueous sodium hydroxide solution. To this dispersion, 200 parts of a 10% aqueous solution of polyvinyl alcohol and 50 parts of starch particles were added, and water was added to the solid content concentration of the microcapsule dispersion to 20.
% Solution was prepared. 5 g of this coating solution on 50 g / m ² base paper
It was coated with an air knife coater so that a solid content of g / m ² was coated and dried to obtain an electron-donating colorless dye-containing capsule sheet.

(2) Preparation of electron-accepting compound sheet Zinc 3,5-bis (α-methylbenzyl) salicylate 1
A dispersion liquid consisting of 4 parts, 80 parts of calcium carbonate, 20 parts of zinc oxide, 1 part of sodium hexametaphosphate and 200 parts of water was dispersed by a sand glider so that the average particle diameter was 3 μm. To this dispersion, 100 parts of a 10% PVA aqueous solution and 10 parts of carboxy-modified SBR latex (as solid content) were added, and water was added so that the solid content concentration became 20% to obtain a coating liquid. This coating solution was applied to 50 g / m ² base paper.
An electron-accepting compound sheet was obtained by coating with an air knife coater so that a solid content of 0 g / m ² was coated and drying.

(3) Pressurized color development test The surface of the microcapsule sheet containing the electron-donating colorless dye was
When a color of 300 kg / cm ² was applied to the electron-accepting compound sheet to develop a color, the color hue was black.

Example 2 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 1 was converted into 2-bis (p-methoxyphenyl).
A microcapsule sheet was obtained by the same procedure as in Example 1 except that amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane was used. When color was developed in the same manner as in Example 1, a black image was obtained instantaneously.

Example 3 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 1 was converted into 2-bis (p-methylphenyl) amino-3-methoxy-6-. A microcapsule sheet was obtained by performing the same operations as in Example 1 except that N-ethyl-Np-tolylaminofluorane was used. When color was developed in the same manner as in Example 1, a black image was obtained instantaneously.

Example 4 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 1 was converted into 2-bis-p-tolylamino-3-.
A microcapsule sheet was obtained in the same manner as in Example 1 except that methoxy-6-diethylaminofluorane was used. When color was developed in the same manner as in Example 1, a black image was obtained instantaneously.

Example 5 The 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 1 was changed to 2-diphenylamino-3-ethylthio-6-diethylaminofluorane. Others were the same as in Example 1 to obtain a microcapsule sheet. When color was developed in the same manner as in Example 1, a red-black image was instantaneously obtained.

Example 6 Electron-donating colorless dye 2
-Bis (p-methoxyphenyl) amino-3-methoxy-6-N-ethyl-Np-tolylaminofluorane,
20 g each of bisphenol A, which is an electron-accepting compound, and 4-ethoxyphenyl-4′-chlorobenzyl ether, which is a heat-fusible compound, were dispersed in a ball mill for 24 hours together with 100 g of a 5% polyvinyl alcohol (Kuraray PVA105) aqueous solution. , And the volume average particle diameter was 3 μ. On the other hand, 80 g of calcined kaolin (Anisilex-93) was dispersed with a homogenizer together with 160 g of a 0.5% solution of sodium hexametaphosphate. Dispersing as described above, each dispersion is mixed at a ratio of 5 g of an electron-donating colorless dye dispersion, 10 g of an electron-accepting compound dispersion, 10 g of a heat-fusible compound dispersion, and 22 g of a calcined kaolin dispersion, Further, 4 g of zinc stearate emulsion and 5 g of an aqueous solution of 2% sodium di (2-ethylhexyl) sulfosuccinate were added to obtain a coating liquid. The coating liquid was applied by a wire bar to a dry coating weight on a high-quality paper with a basis weight of 50 g / m ² is 6 g / m ^2, to obtain a coated paper subjected to calendering treatment.
The coated paper obtained as described above was printed with a thermal head (KLT-216-8MPD1) manufactured by Kyocera Corp. to obtain a black image.

Example 7 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 6 was converted into 2-bis (p-methylphenyl) amino-3-methoxy-6-. A coated paper was obtained in the same manner as in Example 6 except that N-ethyl-Np-tolylaminofluorane was used. When printed in the same manner as in Example 6, a black image was obtained.

Example 8 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 6 was converted into 2-bis-p-tolylamino-3-.
A coated paper was obtained in the same manner as in Example 6 except that methylthio-6-N-ethyl-Np-tolylaminofluorane was used. When printed in the same manner as in Example 6, a red-black image was obtained.

Example 9 The 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 6 was converted into 2-N- (p-methoxyphenyl).
A coated paper was obtained in the same manner as in Example 6 except that -N-phenylamino-3-methoxy-6-diethylaminofluorane was used. When printed in the same manner as in Example 6, a black image was obtained.

[Embodiment 10] 2-bis (p-
Methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane was added to 2-N- (p-methoxyphenyl) -N-p-tolylamino-3-methylthio-6-N.
A coated paper was obtained in the same manner as in Example 6 except that ethyl-N-p-tolylaminofluorane was used. When printed in the same manner as in Example 6, a red-black image was obtained.

[Comparative Example 1] 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 1 was replaced with 2-anilino-3-methyl-6-diethylaminofluorane. A microcapsule sheet was obtained in the same manner as in Example 1. When color was developed in the same manner as in Example 1, a red-black image was instantaneously obtained.

[Comparative Example 2] 2-bis (p-methoxyphenyl) amino-3-methoxy-6-diethylaminofluorane of Example 4 was replaced with 2-anilino-3-methyl-6-diethylaminofluorane. In the same manner as in Example 6, the coated paper was obtained. When printed in the same manner as in Example 6, a red-black image was obtained.

The image densities of the recording materials obtained in Examples and Comparative Examples were evaluated by using Macbeth reflection densitometer (RD).
-918 type).

The evaluation of the light fastness of the color image was carried out by measuring the image densities after the light fastness accelerating test for the image area with a Macbeth reflection densitometer. The light fastness test was carried out by illuminating with a weatherometer (Xenon lamp, 6000 W, manufactured by Atlas, USA) for 12 hours.

The results are shown in Table 1.

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[Table 1]

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According to the present invention, the density of the color image is high,
It is possible to obtain a recording material which gives a color image having good light resistance.

Claims (2)

[Claims] 1. A recording material using an electron-donating colorless dye and an electron-accepting compound, wherein a 2-diphenylamino-3-alkoxy-6-aminofluorane compound or 2-diphenylamino-3-alkylthio is used as the electron-donating colorless dye. A recording material containing a 6-aminofluorane compound. 2. The recording material according to claim 1, wherein the alkoxy group or alkylthio group at the 3-position has 1 to 4 carbon atoms.