JPH03175083A - Recording material - Google Patents

Abstract

PURPOSE:To enhance coloring properties and the stability of a colored image and a non-colored image part by adding an electron donative colorless dye and a mixed metal salt of a specific salicylic acid derivative and an aliphatic acid derivative having a benzotriazol group as a substitution group. CONSTITUTION:This recording material contains an electron donative colorless dye and a mixed metal salt of a salicylic acid derivative and an aliphatic acid derivative having a benzotriazol group as a substitution group as expressed by formula (I). In the formula, the groups expressed by R1, R2, R3 are a hydrogn atom, an alkyl group or an aryl group. This salicylic acid derivative is easily synthesized by subjecting the corresponding phenol derivative to a Kolbe-schmitt reaction. It is recommended that an electron receptive compound be used at 50 to 5,000 weight% for the electron donative colorless dye in a recording mate rial. Furthermore, it is ideal that the salicylic acid derivative is contained at the ratio of more than 10 weight% for the electron receptive compound.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a recording material, and more particularly to a recording material with improved stability in two color-developing image areas and a non-image area.

(Prior Art) Recording materials using electron-donating colorless dyes and electron-accepting compounds are already well known. For example, British patent 21
40449, U.S. Patent No. 4480052, U.S. Patent No. 443692
0, JP-A-62-144゜989, etc., for details.

In recent years, research has been conducted to improve properties of recording materials, such as (I) color density and color sensitivity, and (2) fastness of color formers.

The present inventors have investigated the oil solubility, solubility in water, partition coefficient, pKa, polarity of substituent, position of substituent, crystallinity when mixed, for each of the electron donating colorless dye and the electron accepting compound. Focusing on characteristics such as changes in solubility, we have pursued the development of good materials for recording materials and recording materials.

(Purpose of the invention) Therefore, the object of the present invention is color development and color images.

It is an object of the present invention to provide a recording material using a material that has good stability in non-image areas and satisfies other requirements.

(Structure of the Invention) The object of the present invention is to provide an electron-donating colorless dye and the following general formula (
It is distantly related to recording materials characterized by containing a mixed metal salt of a salicylic acid derivative represented by I) and a fatty acid derivative having a benzotriazole group as a substituent.

In the above formula, RI+ RL R! , and R4 represent a hydrogen atom, an alkyl group or an aryl group.

In the above formula, the groups represented by R, Rt, R, and R1 further include an alkyl group, an alkenyl group, an aryl group, a hydrogen atom, an alkoxy group, an aryloxy group, an alkylthio group, a halogen atom, a nitro group, It may be monosubstituted with a cyano group, a heterocycle, etc. These substituents may further have a substituent. R,, Rt, Rs, and R
Specific examples of the group represented by 4 include a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and 1 carbon atom. -20 alkoxy groups are preferred, and hydrogen atoms are particularly preferred.

Alkyl group having 1 to 20 carbon atoms, 7 to 20 carbon atoms
An aralkyl group is preferred.

The present invention, which shows specific examples of salicylic acid derivatives according to the present invention, is not limited to these examples.

3.5-bis(-α-methylbenzyl)salicylic acid, 3
-α-Benzylated phenylethylsalicylic acid, 3-α-
Methyl-α-ethylpentyl-5-α, α-dimethylbenzylsalicylic acid, 3-cumyl-5-t-octylsalicylic acid, 3-cumyl-5-t-butylsalicylic acid, 3-
1-Butyl-5-cumylsalicylic acid, 3,5-di-t-
Butylsalicylic acid, 3,5-di-t-octylsalicylic acid.

3.5-di-t-nonylsalicylic acid, 3.5-bis(methylcumyl)salicylic acid, 3,5-biscumylsalicylic acid, 3-α-methylbenzyl-6-methylsalicylic acid, 3-α-benzylated phenylethyl- 6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-6-
Methyl salicylic acid.

3.5-bis(-α-benzylated phenylethyl)salicylic acid, 3,5-bis(benzylated benzyl)salicylic acid, 3,5-bis(α-methylbenzyl)-6-methylsalicylic acid, 3-α-tolylethyl -6-methylsalicylic acid, 3,5-bis(α,α-dimethylbenzyl)-6
-Methylsalicylic acid, 3,5-di and monooctyl to 6-
Methylsalicylic acid, 3-α-dimethylphenylethyl 6
-Methylsalicylic acid, 3-α-ethylphenylethyl-
6-methylsalicylic acid, 3-α-isopropylphenylethyl-6-methylsalicylic acid.

3-α-benzylated benzylphenylethyl-6-methylsalicylic acid, 3-α-methyl-α-ethylpentyl-
Examples include 6-ethylsalicylic acid 2 and the like.

The salicylic acid derivatives according to the present invention are easily synthesized by subjecting the corresponding phenol derivatives to a Kolbe-Schmidt reaction. .

The fatty acid derivative having a benzotriazole group as a substituent according to the present invention is preferably one represented by the following general formula.

(In the above formula, n is an integer from 2 to 10, Y and Z are hydrogen atoms, alkyl groups, alkoxy groups, aryloxy groups, halogen atoms, substituted amino groups, cyano groups, nitro groups, acyl groups, trihalomethyl groups. .

R6 represents a tertiary alkyl group. ) Typical specific examples of fatty acid derivatives having a benzotriazole group as a substituent according to the present invention include 3-+5-
t-Butyl-3-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl)propionic acid, 3- +5-butyl-3-(2H-benzotriazol-2-yl)- Examples include, but are not limited to, 4-hydroxyphenyl)propionic acid 2 and the like.

The mixed metal salts according to the present invention include zinc salts, aluminum salts, magnesium salts, and calcium salts.

Sodium salts, nickel salts, etc. are preferred, and zinc salts and nickel salts are particularly preferred.

The mixed metal salt of a salicylic acid derivative and a fatty acid derivative having a benzotriazole group as a substituent according to the present invention is 9
For example, it can be easily obtained by converting a corresponding salicylic acid derivative and a fatty acid derivative having a benzotriazole group as a substituent into an alkali metal salt, and then reacting the resulting salt with a corresponding metal halide, sulfate, or the like.

The recording material according to the present invention further includes well-known materials other than the present invention, such as phenol derivatives, salicylic acid derivatives, metal salts of aromatic carboxylic acids, acid clay, bentonite, and novolac resins.

Metal-treated novolac resins, metal complexes, etc. may be used in combination; examples of these are JP-A-40-9309, JP-A-45-14039, JP-A-52-140483, JP-A-48-51510. .

JP-A-57-21O886, JP-A-58-87089
No., JP-A-59-11286, JP-A-60-176
No. 795, JP-A No. 61-95988, etc. Among these, combination use with bisphenol derivatives or salicylic acid derivatives is preferred, and combination use with zinc salt of 3,5-bis(α-methylbenzyl)salicylic acid is particularly preferred.

Electron-donating colorless dyes according to the present invention include triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, indolyl phthalide compounds, leucoauramine compounds, rhodamine lactam compounds, and triphenylmethane compounds. , triazene compounds, spiropyran compounds, and fluorene compounds.

Specific examples of phthalides are given in U.S. Reissue Patent Specification No. 23.0.
No. 24, U.S. Patent Nos. 3,491,111, 3,491,112, 3,491.116 and 3,509,174.

Specific examples of fluorans are given in U.S. Pat. No. 3,624.
No. 107, No. 3,627,787, No. 3,641
, No. 011, No. 3,462,828, No. 3,68
No. 1,390, No. 3,920.510, No. 3.9
No. 59,571, specific examples of spiropyrans are given in US Pat. No. 3,971.808, and pyridine and pyrazine compounds are given in US Patent No. 3,775,424.

No. 3,853,869, No. 4,246,318, and specific examples of fluorene compounds are given in Japanese Patent Application No. 61-2409.
It is described in No. 89 etc.

In the recording material according to the present invention, the electron-accepting compound is preferably used in an amount of 50 to 5000% by weight, more preferably 100 to 2000% by weight of the electron-donating colorless dye.
It is. It is preferable that the salicylic acid derivative of the present invention is contained in the electron-accepting compound in an amount of 10% by weight or more, particularly 20% by weight or more.
It is preferable that it is contained in an amount of % by weight or more.

When these are applied to recording materials, they are used in the form of fine dispersions, minute droplets, or films.

Furthermore, in this case, various additives well known in the fields of recording materials and polymer resins, such as pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, and fluorescent dyes, may be added. ．． Additives such as surfactants are used.

For use with pressure sensitive paper, U.S. Patent No. 2,505.47
No. 0, No. 2,505.471, No. 2゜505.489
No. 2,548.366, No. 2.712,507, No. 2,730,456, No. 2,730,457,
It takes various forms as described in prior patents such as No. 3,103,404, No. 3,418,250, and No. 4.010.038. It most commonly consists of at least one pair of sheets containing separately an electron-donating colorless dye and an electron-accepting compound.

A method of manufacturing capsules is described in U.S. Pat. No. 2.800.
457, a method using coacervation of a hydrophilic colloid sol described in British Patent Nos. 2,800,458, British Patent No. 867.797, British Patent No. 950,443, British Patent No. 98
No. 9,264, Ibid.

Examples include the interfacial polymerization method described in US Pat. No. 091.076 and the method described in US Pat. No. 3,103,404.

In general, electron-donating colorless dyes are used alone or in combination as solvents (alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, alkylated terphenyl, alkylated terphenyl, etc.).
Synthetic oils such as chlorinated paraffin, vegetable oils such as cotton oil and castor oil, animal oils, mineral oils, or mixtures thereof) are dissolved in microcapsules to produce paper, high-quality paper, plastic sheets, resin coatings, etc. Hang the coloring agent sheet by applying it to ted paper, etc.

In addition, an electron-accepting compound and, if necessary, additives, alone or in combination, are dispersed in a binder such as styrene-butadiene latex or polyvinyl alcohol, and the pigment is used together with a support such as paper, plastic sheet, or resin-coated paper. A developer sheet is obtained.

As a binder, carboxyl-modified styrene-butadiene latex and water-soluble polymer were used at a weight ratio of 9, 50:5.
It is preferable to use a ratio of 0 to 25 near 5.

The carboxyl-modified styrene-butadiene latex is preferably one modified with an unsaturated acid, such as acrylic acid, methacrylic acid, maleic acid, or itaconic acid. As the water-soluble polymer, polyvinyl alcohol or maleic anhydride is preferable. - Isobutylene copolymer, carboxymethyl cellulose, hydroxyethyl cellulose, polyacrylamide, polyacrylic acid.

Synthetic or natural polymers such as polyvinylpyrrolidone, starch, casein, gum arabic, gelatin, etc. can be used.

If the usage ratio of the carboxyl-modified styrene-butadiene latex is higher than 50, the light resistance of the dichromator and the yellowing of the color developing surface due to light will deteriorate. Furthermore, when the ratio of carboxyl-modified styrene-butadiene latex used is lower than 25, the water resistance of the color developing surface deteriorates.

In addition, pigments include zinc oxide, aluminum hydroxide,
Examples include calcium carbonate, titanium oxide, magnesium carbonate, magnesium oxide, barium sulfate, kaolin, activated clay, and talc.

Among these, calcium carbonate with an average particle size of 5.0 μ or less,
It is particularly preferable to use 60% by weight or more of the total pigment.
If the amount of calcium carbonate used is less than 60% by weight, sufficient performance in light resistance of the dichromator and yellowing of the color developing surface due to light cannot be obtained.

In addition, sufficient color developing ability cannot be obtained unless calcium carbonate with an average particle size of 5.0 μ or less is used.
Calcium carbonate with a size of less than μ is available as a commercial product such as Shiraishi Kogyo's Br1lliant-15 and Br1lliant.
-8,15,Br1lliant-30,PC,PCX
, Unibur-70, etc.

The electron-accepting compound and the pigment are preferably used in a weight ratio of 1:5 to 1:15.2. Sufficient color developing ability cannot be obtained.

The electron-accepting compound and pigment are mechanically dispersed in an aqueous system using a ball mill, an attritor sand mill, etc. together with a dispersant, a water-soluble polymer, and other additives to obtain a dispersion. Some of the electron-accepting compounds are prepared as an emulsion by dissolving the electron-accepting compound in an organic solvent and emulsifying it in water.
You can also use

The amount of electron-accepting compound applied to the support.

0.1 g/m' ~2. Og/m”, preferably 0
2 g/m" to 1.0 g/m" is suitable.

The amount of the electron-donating colorless dye to be used 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 depending on the conditions.

It is easy for one skilled in the art to determine this amount to use.

When used for thermal paper, JP-A-62-144゜989
No. 62-244,883, etc. Specifically, the electron-donating colorless dye and the electron-accepting compound are 10μ or less in the dispersion medium,
The zero dispersion medium is preferably pulverized and dispersed to a particle size of 3μ or less.

Generally, an aqueous polymer solution having a concentration of about 0.5 to 10% is used, and dispersion is carried out using a ball mill, sand mill, horizontal sand mill, attritor, colloidal mill, etc.

The ratio of the electron-donating colorless dye to the electron-accepting compound used is preferably between 1:10 and 1:1, and particularly preferably between 1:5 and 2=3.

At that time, a thermofusible substance can be included in the thermosensitive coloring layer in order to improve thermal responsiveness. Representative thermofusible substances include aromatic ethers, thioethers, esters, and/or aliphatic amides or ureides.

Examples of these are JP-A-58-57989 and JP-A-58-87.
No. 094, No. 61-58789, No. 62-10968
No. 1, No. 62-132674, No. 63-151478
No. 63-235961, patent application No. 1-4447,
It is described in the same No. L-37070.

These are used in finely dispersed form at the same time as the electron-donating colorless dye or simultaneously with the electron-accepting compound. These are added at a weight ratio of 20% or more and 300% or less, particularly preferably 40% or more and 150% or less, based on the electron-accepting compound.

Additives may be added to the thus obtained coating liquid as necessary to meet various requirements. An example of an additive is an inorganic pigment in the binder to prevent staining of the recording head during recording.

Oil-absorbing substances such as polyurea fillers are dispersed, and fatty acids, metal soaps, and the like are added to improve mold release properties from the head. Therefore, in general, in addition to electron-donating colorless dyes and electron-accepting compounds that directly contribute to color development, thermofusible substances, pigments, waxes, antistatic agents, ultraviolet absorbers, antifoaming agents, conductive agents, and fluorescent dyes are used. ,
Additives such as surfactants are applied onto the support to constitute the recording material.

The obtained heat-sensitive coating liquid is applied to high-quality paper, high-quality paper with an undercoat layer, synthetic paper, plastic film, etc. In this case, it is particularly preferable to use a support having a smoothness defined by JIS-8119 of 500 seconds or more, particularly 800 seconds or more, from the viewpoint of dot reproducibility.

(Examples of the invention) Examples are shown below, but the present invention is not limited thereto.9% by weight unless otherwise specified in the examples.
represents.

Example-1 1) Preparation of capsule sheet containing electron-donating colorless dye 5 parts of a partial sodium salt of polyvinylbenzenesulfonic acid (manufactured by National Starch, VER3A, TL500) is dissolved in 95 parts of hot water and then cooled. A sodium hydroxide aqueous solution was added to this to adjust the pH to 4.0. Separately, 100 parts of diisopropylnaphthalene in which 4.5% of 3-(2-ethoxy-4-diethylaminophenyl)-3-(I-octyl-2-methylindol-3-yl)phthalide, an electron-donating colorless dye, was dissolved was added to the The mixture was emulsified and dispersed in 100 parts of a 5% aqueous solution of a partial sodium salt of polyvinylbenzenesulfonic acid to obtain an emulsion having a particle size of 4.0 μm in diameter. Separately, 6 parts of melamine, 11 parts of a 37% by weight aqueous formaldehyde solution, and 30 parts of water were heated and stirred at 60'C, and after 30 minutes, a transparent aqueous solution of a melamine-formaldehyde prepolymer was obtained.

This aqueous solution was mixed with the above emulsion. While stirring, the pH was adjusted to 6.0 with a 2M phosphoric acid solution, the liquid temperature was raised to 65°C, and stirring was continued for 6 hours. This capsule liquid 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% by weight polyvinyl alcohol aqueous solution and 50 parts of starch particles were added and water was added to prepare a solution of a microcapsule dispersion with a solid content concentration of 20%.

This coating liquid was coated on a 50 g/m'' base paper using an air knife coater so that the solid content was 5 g/m'' and dried to obtain a capsule sheet containing an electron-donating colorless dye.

2) Preparation of electron-accepting compound sheet 3,5-bis(-α-methylbenzyl)salicylic acid and 3
- 4 parts of equimolar mixed zinc salt of [5-tert-butyl-3-(28-benzotriazol-2-yl)-4-hydroxyphenyl)propionic acid.

80 parts of calcium carbonate with an average particle size of 5.0 μm or less.

A dispersion liquid consisting of 20 parts of zinc oxide, 1 part of sodium hexametaphosphate and 200 parts of water was dispersed using a sand glider so that the average particle size was 3 μm. This dispersion has lO%PV
100 parts of A aqueous solution and 10 parts of carboxy-modified SBR latex (as solid content) were added, and the solid content concentration was 20 parts.
% to obtain a coating liquid. 50g of this coating liquid
/m'' base paper was coated with an air knife coater so that the solid content was 5.0 g/m'', and dried to obtain an electron-accepting compound sheet.

The surface of the microcapsule sheet containing an electron-donating colorless dye is
The electron-accepting compound sheet was layered and a load of 400 kg/cm2 was applied to develop color. The spectral absorption of the coloring material was measured between wavelengths of 400 to 780 nm.

When the density at absorption maximum was measured, the color density was 1.
It was 02.

In addition, in order to examine photodiscoloration of the color developer sheet obtained in 2), the color developer sheet was subjected to a fluorescent lamp fading tester (33,0001
The density of the color developer sheet that was irradiated for 20 hours with UV light was 0.10.

Furthermore, when 9 colors were developed using this color developer sheet, 1
The color density was 0.98.

Example 2 A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1 except that only the electron-donating colorless dye was replaced with crystalline violet lactone. When color was developed in the same manner as in Example 1, the 1 color density was 1.07. In addition, a light resistance test was conducted in Example 1. When color was developed using a color developer sheet, the color density of 9 was 1.07.

Example 3 Only electron-accepting compounds were used, 3,5-bis(-α-methylbenzyl)salicylic acid and 3-(5-butyl-3-
(2H-benzotriazol-2-yl)-4-hydroxyphenyl)propionic acid mixed with an equimolar mixture of nickel salt and 3,5-bis(-α-methylbenzyl)zinc salicylate in an equal weight mixture. An electron-accepting compound sheet was obtained in the same manner as in Example 1. When the color was developed in the same manner as in Example 1, the density of the two colors was 1.03.

Further, in the same manner as in Example 1, a light resistance test of the color developer sheet was conducted. When the density of the developer sheet was measured, it was 0.
It was 12. Furthermore, when nine colors were developed using this color developer sheet, the density of one color was 0°97.

Example 4 Only the electron-accepting compounds were 3,5-di-t-octylsalicylic acid and 3-[5-t-butyl-3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl)propion. Equimolar mixed zinc salt of acid and 3,5-di-t-
Octylsalicylic acid and 3-(5-t-butyl-3-(2
An electron-accepting compound sheet was obtained in the same manner as in Example 1 except that an 8:2 weight mixture of an equimolar mixed nickel salt of H-benzotriazol-2-yl)-4-hydroxyphenyl 1-propionic acid was used. . When color was developed using the electron-donating colorless dye-containing microcapsule sheet used in Example 2, the single color density was 1.09. Also, in the same manner as in Example 1.

A light resistance test of the color developer sheet was conducted. When the density of the developer sheet was measured, it was 0. It was lO. Furthermore, when 9 colors were developed using this color developer sheet, the density of 2 colors was 1.
It was 07.

Example-5 Only the electron-donating colorless dye is 2-anilino-3-methyl-
A microcapsule sheet containing an electron-donating colorless dye was obtained in the same manner as in Example 1 except that 6-N-ethyl-N-isoamylaminofluorane was used.

When the color was developed in the same manner as in Example 1, the color density of 9 was 0.
．． It was 97.

Comparative Example 1 An electron-accepting compound sheet was obtained in the same manner as in Example 1 except that 12 parts of zinc 3,5-bis-α-methylbenzylsalicylate was used as the electron-accepting compound.

When the color was developed in the same manner as in Example 1, the color density was 1.
．． It was 01.

In addition, when we conducted a light resistance test on the color developer sheet, the density was 0.
．． It was 20. Furthermore, when two colors were developed using this color developer sheet, the density of the two colors was 0.76.

Comparative Example 2 An electron-accepting compound sheet was obtained in the same manner as in Example 1 except that only the electron-accepting compound was changed to a formalin condensate of p-phenylphenol. When color was developed in the same manner as in Example 1, the color density of 9 was 0.88.

In addition, when we conducted a light resistance test on the color developer sheet, the density was 0.
．． It was 29.

As described above, it can be seen that the pressure-sensitive recording material of the present invention has a high two-color density, little discoloration of the color developer sheet, and little decrease in color development ability.

Claims (1)

[Scope of Claims] A record characterized by containing an electron-donating colorless dye and a mixed metal salt of a salicylic acid derivative represented by the following general formula (I) and a fatty acid derivative having a benzotriazole group as a substituent. material. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the above formula, the groups represented by R_1, R_2, R_3, and R_4 represent a hydrogen atom, an alkyl group, or an aryl group.