JPS63128979A - Recording sheet - Google Patents

Abstract

PURPOSE:To improve light fasteness of a microcapsule layer by adding p- substituted aminophenylindolylazaphthalide derivative and bisindolylphthalide derivative to an electron donor dye. CONSTITUTION:Bisindrylphthalide compounds as a color developing agent should preferably have hydrogen atoms and the methyl groups or phenyl group in the formula I. From a viewpoint of coloring element stability, it is desirable to use p-substituted aminophenylindolylazaphthalide derivative and bisindolylphthalide derivative so that the combined amount of these ingredients may be for instance, at least 30 weight% of the total amount of the color developing agent. The color developing agent used is applied to a support after being dissolved in a solvent and filled in a capsule.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording sheet, and more particularly to a recording sheet that utilizes a color-forming reaction between a nearly colorless electron-donating dye and an electron-accepting compound.

(Prior art) Recording sheets using almost colorless electron-donating dye C (hereinafter referred to as color former) and electron-accepting compound F (hereinafter referred to as color developer) are pressure-sensitive paper, thermal paper, light-sensitive pressure-sensitive paper, and electrically conductive heat-sensitive paper. It is already well known as recording paper.

For example, British patent 2/ll-0≠≠, U.S. patent μgtootλ, same≠≠36220, Japanese Patent Publication No. 7-7-7, r3t, same to-/λ3.
j! Otsu, I am familiar with TO-L Co. J, JJ7, etc.

The performance that a recording sheet should have is (1) sufficient color density and color development sensitivity, (2) no fogging, (3) sufficient fastness of the color material, and (4) color development. The light resistance of the microcapsule layer containing the agent is sufficient.

In these recording sheets, it has already been proposed to use p-substituted aminophenylindolyl azaphthalide derivatives as color formers to provide color formers with extremely excellent fastness. /-/4107, Tokuko Sho 31
-31.2143, Tokuko Sholl-20791, Tokuko Sho4
/-4Arjt etc.).

However, recording seeds containing this p-substituted aminophenylindolyl azaphthalide derivative in microcapsules have the disadvantage that the microcapsule layer does not have sufficient light resistance (the color development property decreases when the ζ microcapsule layer is irradiated with light). contains.

f) An object of the present invention is to provide a recording sheet containing p-substituted aminophenylindolyl azaphthalide as a coloring agent in microcapsules, in which the light resistance of the microcapsule layer is improved. be.

(Structure of the Invention) An object of the present invention is to provide a recording sheet containing microcapsules containing an almost colorless electron-donating dye, which includes (a) a p-substituted aminophenylindolyl azaphthalide derivative as the electron-donating dye; (b) This was achieved by a recording sheet characterized by containing a bisindolyl phthalide derivative represented by the general formula [I].

In formula C, R1 and R1' are alkyl groups having 6 to 11 carbon atoms, or aryl groups having 6 to 1λ carbon atoms, R2 and R2/ are hydrogen atoms, alkyl groups having 1 to 1 carbon atoms, or carbon atoms. Represents a number of aryls. ) The p-fit-substituted aminophenylindolyl azaphthalide compound used as the coloring agent of the present invention is preferably one represented by the following general formula.

In the above formula, one of [and Y represents -N=, the other represents -CH='i, and Z is a hydrogen atom, a halogen atom,
01 to C8 alkyl group, C1 to C12 alkoxy group, C6 to C18 aryloxy group, and 1dc7 to C
13 aralkyloxy group, W represents a hydrogen atom or a halogen atom, and R1 is a hydrogen atom or an unsubstituted or halogen atom having up to 7.2 carbon atoms, a hydroxyl group, a cyano group, and a lower alkoxy group. Represents a substituted alkyl group, R2 is a hydrogen atom, 01-
C8 alkyl group or C6-C12 allyl group, R
3 and R4 are a hydrogen atom or an alkyl group substituted with an unsubstituted or norogen atom having up to 12 carbon atoms, a hydroxyl group, a cyano group, or a lower alkoxy group, a C5 to C7 cygloalkyl group; , a benzyl group, or a phenyl group, and -NR3R4 may further form a pyrrolidinyl group.

The bisindolyl phthalide compound used as the coloring agent of the present invention, which is preferable as the p-tFJ, substituted aminophenylindolyl azaphthalide compound represented by the above general formula, is as follows:
In general formula CI], R2 and R2' are preferably a hydrogen atom, a methyl group, or a phenyl group.

Preferred specific examples of the bisindolyl phthalide compound represented by the general formula [I] are shown in Table 2.

In addition to p-substituted aminophenylindolyl azaphthalide derivatives and bisindolyl phthalide derivatives, color formers include triphenylmethane phthalide compounds, fluoran compounds, fetchaziy compounds, indolyl phthalide compounds, Leuco auramine compounds, rhodamine lactam compounds, triphenylmethane compounds, triazene compounds, spiropyran compounds, etc. may be used in combination. As the coloring agent used in combination, crystal violet lactone is preferable in terms of hue and coloring density.

In this case, the total amount of (a) the p-substituted aminophenylindolyl azaphthalide derivative and (b) the bis-indolylphthalide derivative of the present invention is used in an amount equal to 30 weight plates of the total amount of the color former. This is desirable from the viewpoint of the fastness of the coloring body. Also, the combination ratio of (a) and (b) is (by weight) (
a)/(b)=jO/jo~ri0/10 is preferable.

The coloring agent used in the present invention is dissolved in a solvent, encapsulated, and applied to a support.

As a solvent, natural or synthetic oils can be used alone or in combination. Examples of solvents include cottonseed oil and kerosene.1. Examples include halafine, naphthenic oil, alkylated biphenyls, alkylated terphenyls, chlorinated roughhenes, alkylated naphthalenes, and diphenylalkanes.

As a method for manufacturing the color former-containing microcapsules, an interfacial polymerization method, an internal polymerization method, a phase separation method, an external polymerization method, a coacervation method, etc. are used.

In preparing a coating solution containing microcapsules containing a color former, a water-soluble binder or a latex binder is generally used. Further, a capsule protectant such as cellulose powder, starch particles, talc, etc. is added to obtain a color former-containing microcapsule coating solution.

Examples of color developers that react with the color forming agent used in the recording sheet of the present invention include acid clay, activated clay, attapulgite, zeolite, bentonite, clay materials such as kaolin, metal salts of aromatic carboxylic acids, and phenol resins. can be given.

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

The performance of the recording sheet of the present invention was tested using the following color developer sheet.

(Adjustment of color developer sheet) 70 parts of water, 2 parts of zinc oxide, 3 parts of calcium carbonate, and 3 parts of calcium carbonate.
．． ! Zinc -di-alpha-methylbenzylsalicylate was added and mixed, and then dispersed for 30 minutes using an attritor, to which 1 carboxy-modified SBR latex was added at a solid content of 2. j
Part and 10wt4PVAC saponification degree is 2, polymerization degree too
o) 12 parts of an aqueous solution was added and stirred uniformly to obtain a coating solution. Apply this coating liquid to a base paper of 7m2 t/m2.
A developer sheet was obtained by coating and drying using an air knife coater capable of coating a solid content of .

Example of invention C) The present invention will be specifically explained below using examples.

The invention is not limited to the examples.

Example/~! And Comparative Example 1~! Part of polyvinylbenzenesulfonic acid adjusted to pHμ) IJum salt (average molecular gzoo,.

OO) Spread, ≠ 100 parts of ice cube solution is emulsified and dispersed with a color former oil prepared by dissolving the color former shown in Table 3 in 7700 parts of diisopropyl naphthalene to obtain an emulsion having an average particle diameter of j, and a particle size of j parts. I got it. Separately, melamine, 37 tqb
Part/part of formaldehyde aqueous solution and 30 parts of water were heated and stirred for 30 minutes to obtain a transparent mixed aqueous solution of melamine, formaldehyde and melamine-formaldehyde initial condensate. The pH of this mixed aqueous solution was 4.0-io. Hereinafter, this mixed aqueous solution of melamine, formaldehyde and melamine-formaldehyde initial mesh will be referred to as an initial condensate solution. The initial condensate solution obtained by the above method was added to and mixed with the above emulsified mixture, and while stirring, the pH was adjusted to t, o with a large weight hydrochloric acid solution, and the liquid temperature was adjusted to 4j-
'C' and continued stirring for 30 minutes. The capsule liquid was cooled to room temperature and adjusted to pH 7°O with 20% by weight sodium hydroxide.

To this capsule dispersion, 100 parts of a 10-wt polyvinyl alcohol aqueous solution, 10 parts of carboxy-modified sBR latex as a solid content, 50 parts of starch particles, and 79,410 parts of cal carbonate were added, and water was added to reduce the solid content concentration.
4 to prepare a coloring agent-containing microcapsule coating solution.

This coating solution fsO9/m2 was coated on a base paper using an air knife coater so that a solid content of 397 m2 was coated, and dried to obtain a microcapsule sheet for pressure-sensitive copying.

Comparative test fil Light resistance of microcapsule layer The microcapsule layers of the examples and comparative microcapsule sheets were irradiated with a warning light fading tester (J3,0o01ux) for j hours, and then stacked on a color developer sheet and tested with J00 Kti/cm
A load pressure of 2 was applied to develop color. After being left in a dark place for 2 daylight hours, the spectral absorption curve of the chromophore between wavelengths of 3ro to 7rOnm was measured, and the density at the absorption maximum was measured.

Separately, unirradiated Example and Comparative microcapsule sheets were stacked on a developer sheet, and a load of J 00 Kg/cm 2 was applied to develop color. After leaving it in the dark for λμ time,
Measure the spectral absorption curve of the chromophore between wavelengths JrO to 7rOnm, and calculate the concentration C Fresh concentration (Do) at absorption maximum.
l was measured.

The measurement of the spectral absorption curve was carried out using Hitachi Color Analyzer 307.
Table 3 shows the light resistance values determined using the following formula using a mold.

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

As shown in Table 3, it can be seen that the light resistance of the microcapsule layer of the microcapsule sheet of the present invention is superior to that of the comparative microcapsule sheet.

Procedural amendment (restraint 1. Indication of the case 1939/2006 Japanese Patent Application No. 27873 2, Title of the invention Record sheet 3, Relationship with the case by the person making the amendment Patent applicant contact information 10
6 2-26-30 Nishi-Azabu, Minato-ku, Tokyo 4, Subject of amendment Column ``Claims'' of the specification and Column 5 of ``Detailed Description of the Invention,'' Contents of amendment l) Patent in the specification The scope of claims is amended as shown in the attached sheet.

2) Page j, line 6 of the specification and correct it.

Attachment "Claims: A recording sheet containing microcapsules containing an almost colorless electron-donating dye, which includes (a) a p-substituted aminophenylindolyl azaphthalide derivative and (b) a general formula as the electron-donating dye. A recording sheet containing a bisindolylphthalide derivative represented by (I).

(In the formula, R1, RI/ is a kyl group at 7 of 7-/I carbon atoms, or an aryl group having 6 to 1 carbon atoms, R2, R2' is a hydrogen atom, and an alkyl group having 1 to t carbon atoms. , or aryl having 6 to 5 carbon atoms

Claims (1)

[Scope of Claims] A recording sheet containing microcapsules containing an almost colorless electron-donating dye, comprising (a) a p-substituted aminophenylindolyl azaphthalide derivative and (b) a p-substituted aminophenylindolyl azaphthalide derivative as the electron-donating dye; A recording sheet characterized by containing a bisindolyl phthalide derivative represented by [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, R_1 and R_1' are alkyl groups having 6 to 18 carbon atoms, or aryl groups having 6 to 12 carbon atoms R_2 and R_2' are hydrogen atoms, (Represents an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 9 carbon atoms.)