JPH01157886A - Recording material - Google Patents

Abstract

PURPOSE:To improve light resistance of a microcapsule layer by using a p- substd. aminophenylindolylphthalide derivative or the like as a color former and using microcapsules containing a phthalic acid ester of the like having a boiling point not lower than a specified temperature therein as a solvent. CONSTITUTION:In a recording material, at least one of a p-substd. aminophenylindolylphthalide derivative, a p-substd. aminopheylindolylazaphthalide derivative and a p-substd. aminophenylindolyldiazaphthalide derivative is used as a color former, and microcapsules containing at least one selected from a phthalic acid ester, a fatty acid ester, a dihydric alcohol ester and an oxyacid ester having a boiling point of at least 280 deg.C at a pressure of 760mmHg in an amount of 1-40wt.% based on the core substance are used as a solvent. The phthalic acid ester or the like remains on a color developed surface after printing, thereby uniformizing a developed color image. Therefore, it is necessary for the boiling point at 760mmHg of the phthalic acid or the like be not lower than 280 deg.C. If the amount of the solvent is less than 1wt.% based on the core substance, the effect of the solvent is poor, whereas an amount of more than 40wt.% worsens the light resistance of the coloring matter.

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 that utilizes a color-forming reaction between a nearly colorless color former and an electron-accepting compound.

(Prior Art) A pressure-sensitive recording sheet is a top paper or an electronic paper in which a microcapsule layer containing microcapsules formed by dissolving a nearly colorless coloring agent in a suitable solvent and microcapsulating oil droplets is coated on a support. A base paper with a developer layer containing a receptor compound (hereinafter referred to as developer) coated on another support, and in some cases a microcapsule layer on one side of the support and a developer layer on the other side. consisting of a combination of medium paper coated with a coloring layer;
Alternatively, the capsules and the color developer may be contained on the same side of the support, or the support may contain either the capsules or the color developer and the other may be coated.

These pressure-sensitive recording papers are, for example, 1 fF-is r in the United States.
Oj, u70, same 2. jOj, urri issue, same co.

jjO, IA7/No., same λ, 730.44!7, same J
, u/Ir, 2, No.-0, etc.

However, these pressure-sensitive recording sheets have the following two practically serious drawbacks.

(1) The light resistance of the microcapsule layer containing the color former is insufficient. ...The color development property decreases due to light irradiation of the microcapsule layer.

(2) The light resistance of the coloring material is insufficient. ...The color density of the developed color image decreases due to light irradiation.

At present, no product has been obtained that completely solves these drawbacks.

(Object of the Invention) An object of the present invention is to provide a recording material in which the light resistance of microcapsules j- is improved.

Another object of the present invention is to provide a recording material with high color density (and improved light resistance of the color forming body).

(Structure of the Invention) A recording material containing a microcapsule containing an almost colorless electron-donating color former and a solvent, and an electron-accepting color developer, in which the color former contains p-substituted aminophenylphenyl/
At least tOW of a dolylphthalide derivative, a PTM aminophenylindolyl azaphthalide derivative, and a p-substituted aminophenylindolyldiazaphthalide derivative is used, and the solvent is a phthalate ester having a boiling point of 210°C or higher at 71,0 H9. This was achieved by a recording material characterized by using microcapsules containing at least one selected from fatty acid esters, dihydric alcohol esters, and oxyacid esters in an amount of 1-μO by weight based on the core substance.

The heptatarate, fatty acid ester, divalent flucol ester, and oxyacid ester according to the present invention remain on the coloring surface even after printing, and have the effect of making the colored image uniform. Therefore, 71. The boiling point of OmH7i must be 2IrOoC or higher. Also io.

It is preferable that the vapor pressure at 0C is /m)l fi or less.

Exemplary compounds are shown below, but the invention is not limited thereto.

Phthalate esters include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, dinonyl phthalate, octyldecyl phthalate, isodecyl phthalate, and phthalate. Examples include butylbenzyl phthalate, dilauryl phthalate, and dicyclohexyl phthalate.

Examples of fatty acid esters include butyl oleate, glycerin monooleate, dibutyl adipate, din-hexyl adipate, dioctyl adipate, diλ ethylhexyl adipate, diisononyl adipate, diisodecyl adipate, dibutyl diglycol adipate, Examples include di-2-ethylhexyl azelaate, dibutyl sepacate, dicoethylhexyl sepa'/7ate, and the like.

Examples of dihydric alcohol esters include diethylene glycol shihenzoate and triethylene glycol dicoethylbrate.

Examples of oxyacid esters include acetyl triethyl citrate, acetyl tributyl citrate, methyl acetyl ricinoleate, and butyl acetyl ricinoleate.

In the recording material according to the present invention, heptatalic acid esters and fatty acid esters are preferred. The solvent is for the core substance/
-uO is used in a range of % by weight, more preferably in a range of 2 to 20% by weight based on the core material. If the solvent is used in such a usage range, if it is less than 1% by weight, the effect of the present invention will be small, and if it is more than 4% by weight, the light resistance of the color former will be significantly deteriorated.

The solvent is used in combination with aromatic hydrocarbons, chlorinated norafine aromatic diethers, paraffin oil, and the like.

Aromatic hydrocarbons include diarylalkane, alkylated naphthalene, and alkylated biphenyl. As the diarylalkane, alkylated diphenylmethane, alkylated diphenylethane, alkylated diphenylpropane, etc. are preferable, and specific examples include dixylylmethane, l-phenyl-7-xylylethane, /-phenyl-2-(trimethylphenyl)ethane, / Examples include -phenyl-7-xylylpropane, l-isopropylphenyl-J-7dynylethane, and the like. Specific examples of alkylated naphthalene include isopropylnaphthalene,
Examples include methylpropylnaphthalene, diethylnaphthalene, diisopropylnaphthalene, ethylisopropylnaphthalene, and methylbutylnaphthalene. Specific examples of alkylated biphenyl include diethylbiphenyl,
Examples include isopropylbiphenyl and methylpropylbiphenyl. Further, as a specific example of chlorinated paraffin, British Patent No. 12, 1. Examples include chlorinated/q rough-in having 6 to 1 carbon atoms as described in the specification of au'y. Preferred among these solvents are l-isopropylphenyl-2-phenylethane and l-phenyl-7-
(dimethylphenyl)ethane and diisopropylnaphthalene.

Specific examples of paraffin oil include those having 6 to 2 carbon atoms.
0, those with branched chains are mentioned.

The p-substituted aminophenylindolylphthalide conductor, p-substituted aminophenylindolyl azaphthalide derivative, and p-substituted aminophenylindolyldiazaphthalide derivative according to the present invention are those represented by the following general formula (1). preferable.

In the above formula, R and R' may be the same or different (,
R□ and R2 may be the same or different and represent a hydrogen atom, an alkyl group or an aryl group, and ring A represents a benzene ring, a pyridine ring or a pyrazine ring. Y, Y' and 2 represent a hydrogen atom, an alkyl group, a halogen atom, a substituted amino group or an alkoxy group.

The aryl group is a phenyl group, a naphthyl group, or a heteroaromatic group, and these include an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, a nitro group, a cyano group, a substituted carbamoyl group, a substituted sulfamoyl group,
It may have a substituent such as a substituted amino group, a substituted oxycarmenyl group, or a substituted oxysulfonyl group. Further, the alkyl group represents a saturated or unsaturated alkyl group or a cycloalkyl group, which may have a substituent such as an aryl group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group.

Among the substituents represented by R or R' in the above formula, an alkyl group having %/2 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an aryl group having t-/2 carbon atoms are preferable. , a halogen atom, an alkoxy group, an aryloxy group, an acyl group, a cyano group, a pyridyl group, a furfuryl group, or the like. R and R' may be bonded to each other to form a ring. Preferably,! Or represents a 6-membered saturated heterocycle. Among the substituents represented by R□, an aryl group having i or il carbon atoms, an alkyl group which may have an alkoxy group, an aryloxy group, or a halogen atom as a substituent, and an alkyl group having 6 to 12 carbon atoms. , an alkoxy group or a phenyl group which may have a halogen atom as a substituent, and among the substituents represented by R2, an alkyl group having carbon atoms/-j, a phenyl group having 4%10 carbon atoms, and hydrogen Atom is preferable, and Ring A is preferably a benzene ring, a pyridine ring containing nitrogen at the μ or 7-position, and a pyrazine ring.~1゜ff1A further represents a halogen atom, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group. group, carbamoyl group,
It may be substituted with a substituted amino group, acyl group, alkanesulfo group, alkoxycarbonyl group, nitro group, cyano group, etc. Among the substituents represented by Y and Y', a hydrogen atom, an alkyl group having 1 to If carbon atoms, an acyloxy group, a substituted amino group, and an alkoxy group are preferred, and an alkoxy group is particularly preferred. Among the substituents represented by Z, hydrogen atoms, alkyl groups and alkoxy groups having carbon atoms/%/J are preferred.

To illustrate some of these, (1) Et C1) C8H17 Et In the recording material according to the present invention, a p-substituted aminophenylindolylphthalide derivative and/or a p-substituted aminophenylindolyl azaphthalide derivative and/or or p-substituted aminophenylindolyldiazaphthalide derivatives include triphenylmethane phthalide compounds, fluoran compounds, phenothiazine compounds, leucoolamine compounds, rhodamine lactam compounds, and triphenylmethane compounds, which are already well known. It is possible to assemble recording materials by using it in combination with various compounds such as triazene compounds, spiropyran compounds, and spiropyran compounds.

In this case, it is preferable to use the colorless dye of the present invention in an amount of 70% or more from the viewpoint of improving properties.

In the microcapsules of the present invention, ultraviolet absorbers, hindered phenol derivatives, hindered amine derivatives, and nickel compounds may be added as additives. Any of these may be dissolved together with color development, or may be dissolved separately and mixed.

As a hindered phenol, at least 2 or 6
Phenol derivatives in which one or more of the positions are substituted with a branched alkyl group are preferred.

Specific examples of these can be found in the patent application 1986-! 7314
It is stated in No. c.

More favorable results can be obtained by incorporating an ultraviolet absorber into the core material.

Preferred ultraviolet absorbers are 2'70 to 310
Salicylic acid-based ultraviolet absorbers having spectral absorption in mμ, such as phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate; 2. μ-dihydroxybenzophenone, 2-hydroxy-φ-methoxybenzophenone, co-hydroxy-μm octoxybenzophenone, 2-hydroxy-terdodecyloxybenzophenone, 2.2'
-Dihydroxy-methoxybenzophenone, co, 2
′-dihydroxy-<C, at-dimethquine benzophenone, co-hydroxy-dermethoxy! - benzophenone ultraviolet absorbers such as sulfobenzophenol,
2(2'-hydroxy-!'-methylphenyl)benzotriazole, 2(2'-hydroxy-1'-ter
t-butylphenyl)benzotriazole, co(2'-
Hydroxy-31,z/-di-tert-butylphenyl)incitriazole, J(,2/-hydroxy-
3'-tert-butyl-t'-methylphenyl)-!
Chlorobenzotriazole 1.2(,2'-hydroxy-31,z/-di-tert-butylphenyl)-
! Benzotriazole-based ultraviolet rays such as -chlorobenzotriazole, J(J'-hydroxy-3/,z/-di-tert-amylphenyl)benzotriazole, 2(2'-hydroxy-μ'-octoxyphenyl)benzotriazole, etc. Absorbent, 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, ethyl-2
-There are cyanoacrylate ultraviolet absorbers such as cyano-J, j'-diphenylacrylate, etc.-0 Among these, benzotriazole ultraviolet absorbers are preferred.

The preferred usage amount of various additives is 3 to 2 to 2 % of the coloring agent.
00% by weight, more preferably to-, t.

O% by weight.

Examples of recording materials containing the microcapsules of the present invention include pressure-sensitive recording materials, heat-sensitive recording materials, and the like.

The most common pressure-sensitive recording materials consist of at least a pair of sheets containing microcapsules containing an electron-donating colorless dye and separately containing an electron-accepting compound.

A method of manufacturing capsules is described in a US patent.

100.1Aj No. 7, Ij00.4crlr, a method using coacervation of a hydrophilic colloid sol, British Patent No. 47,79'7, Ij J-
0, μμ3, same j, 26≠, same l.

Examples include the interfacial polymerization method described in U.S. Pat.

The heat-sensitive recording material can take the form as described in Japanese Patent Application No. 222-14. Most commonly, microcapsules containing a color former and a color developer are dispersed and coated on the same sheet.

As an example of an electron-accepting color developer that reacts with the color forming agent used in the recording sheet of the present invention, Japanese Patent Application No. 6.2-ozrr
The one described in No. tu is preferred.

These color developers are applied to a support such as paper along with a binder such as styrene butadiene latex.

The performance of the microcapsule sheet for pressure-sensitive recording of the present invention was tested using the following color developer C)Y.

[Adjustment of color developer sheet]

70 parts of water, 2 parts of zinc oxide, 17 parts of calcium carbonate, and 3 parts
．． ! 2.5% of carboxy-modified SBR latex was added to the solution in which ψ parts of zinc-α-methylbenzylsalicylate were added and mixed, and then dispersed for 30 minutes using an attritor.
and 10 wt% PVA (Saponification degree Tata%, 100 wt% for polymerization)
0) 2 parts of water bath liquid was added and stirred uniformly to prepare a coating liquid. Apply this coating liquid to 109/m2 base paper at a rate of ug/m
A developer sheet was obtained by coating and drying using an air knife coater capable of coating the solid content of No. 2.

Hereinafter, the present invention will be specifically explained with reference to Examples.

The invention is not limited to the examples.

Examples 1-7 and Comparative Examples/-3 Partial sodium salt of polyvinylbenzenesulfonic acid adjusted to pH=6.0 (average molecule *r.

o, ooo) Nobi,! % aqueous solution/20 parts as an ultraviolet absorber.
rt-7'tylphenyl)-y-chlorobenzotriazole and 190 parts of a color former oil prepared by dissolving 2 parts of the color former shown in Table 1 in the solvent shown in Table 1 are emulsified and dispersed to obtain an average particle diameter of r, rμm. An emulsion with a particle size of . Separately, 6 parts of melamine, 37 parts of a 37% formaldehyde aqueous solution, and 30 parts of water were heated and stirred at 400C, and after 30 minutes, a transparent mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate was obtained. The pH ktA of this mixed aqueous solution was 1r-4.o. Hereinafter, this mixed aqueous solution of melamine, formaldehyde, and melamine-formaldehyde initial condensate will be referred to as an initial condensate solution. The initial condensate solution obtained by the above method was added and mixed to the above emulsified mixture, and the pH was adjusted with 3.6 weight 1:% hydrochloric acid solution while stirring.
6. The liquid temperature was raised to ya'4t'C, and stirring was continued for 360 minutes.

The capsule liquid was cooled to room temperature and adjusted to pH 2.0 with 20% by weight sodium hydroxide.

To this capsule dispersion, 100 parts of 1Ot% polyvinyl alcohol aqueous solution, 10 parts of carboxy-modified SBR latex as a solid content, 10 parts of starch particles JO, and 10 parts of calcium carbonate were added, and water was added to bring the solid content concentration to 20.
% to prepare a coloring agent-containing microcapsule coating solution.

Apply this coating liquid to 30 fl/m2 base paper≠77/m
The mixture was coated using an air knife coater so that the solid content of No. 2 was coated, and dried to obtain a microcapsule sheet for pressure-sensitive copying.

Comparative test (1) Light resistance of microcapsule layer After irradiating the microcapsule layers of the examples and comparative microcapsule sheets with a fluorescent light fading tester (<33,0001 ux) for t hours, overlaying them on a developer sheet, A load of 300 kg and 7 cm was applied to develop color. After leaving it in the dark for 2 hours,
The spectral absorption curve of the chromophore was measured between wavelengths of 310 to 710 nm, and the density at the absorption maximum was measured.

Separately, non-irradiated Example and Comparative microcapsule sheets were stacked on a developer sheet, and a load pressure of j 00 kp/tM2 was applied to develop color. After leaving it in the dark for 2tI-hours, the spectral absorption curve of the chromophore between wavelengths sro and 7rOnm was measured, and the concentration at the maximum absorption (fresh concentration) was measured.
Do)) was measured.

The measurement of the spectral absorption curve was carried out using Hitachi Color Analyzer 307.
Table 1 shows the light fastness values determined using a mold using the following formula.

The larger the light resistance value, the better the light resistance of the microcapsule layer.

(2) Light resistance of color forming material The microcapsule sheets of Examples and Comparative were stacked on the developer sheet and a load of 300 kt)/l:m was applied to develop color. After leaving it in the dark for 24C, the wavelength was 31.
The spectral absorption curve of the color former between 0 and 710 nm was measured, and the concentration at the absorption maximum (fresh concentration (Do)) was measured.

This color body! Xenon fade meter (Suga Test Instruments,
After irradiation with FAL-JjAX-HC type for μ hours, the spectral absorption curve of the chromophore was measured, and the concentration (D
) was measured.

The spectral absorption curve was measured using Hitachi Color Analyzer Model 307. Do and Dl at this time are shown.

The larger the Do value, the better the coloring density, and the larger the D value, the better the resistance to colored substances.

As shown in Table 1, it can be seen that the microcapsule sheet of the present invention is superior to the comparative microcapsule sheet in the light-fast coloring density of the microcapsule layer and the light-fastness of the coloring material.

Claims (1)

[Claims] In a recording material containing a microcapsule containing an almost colorless electron-donating color former and a solvent and an electron-accepting color developer, the color former includes a p-substituted aminophenylindolphthalide derivative, a p-substituted aminophenyl At least one of an indolyl azaphthalide derivative and a p-substituted aminophenylindolyl diazapthalide derivative is used, and the solvent is a phthalate ester, a fatty acid ester, a dihydric alcohol ester, or an oxyalcohol ester having a boiling point of 280°C or higher at 760 mmHg. A recording material characterized by using microcapsules containing 1 to 40% by weight of at least one acid ester based on the core substance.