JPH02219680A - Coloring sheet for non-carbon pressure sensitive recording material - Google Patents

Abstract

PURPOSE:To obtain a color forming sheet for non-carbon pressure sensitive recording material suited to high practical use with the superior drying property of desensitizing ink and steady coloring speed by adding sepiolite which is a natural fibrous clay mineral as a pigment. CONSTITUTION:A pigment to be mixed for use is natural fibrous clay mineral, a main constituent of which is hydrated magnesium silicate. This material has a crystal structure of monofilament with a cross-section which appears to be a pile of talc (magnesium silicate) pieces laid over each other alternately. In addition, the filament has so many tunnels about 5.6 in diameter and about 11.0A in length. These tunnels has a peculiar adsorbing effect which is characteristics of thioxotropy represented by bentonite, adsorbing property by zeolite and plasticity by kaolin. Furthermore, sepiolite is effectively compatible with any kind of organic color forming agent, especially with salicylate resin multivalent metal powder.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a color developer sheet for pressure-sensitive recording materials, and further VC*l#C relates to ink drying properties of the color developer sheet. It is.

CB) Conventional Technology Manufacturers Pressure-sensitive recording materials are well known, and as described in, for example, U.S. Pat. No. 2,712,507 and U.S. Pat. This is a recording material that combines a color former sheet coated with an electron-donating (leuco) dye and a developer sheet coated with an electron-accepting color developer '1, and utilizes a color-forming reaction caused by contact between the two.

Traditionally, microencapsulation methods include coacervage, n-method, and intracrystalline method. The (leuco) dyes used include crystal violet lactone, 3-3bis(Yumeichi dimethylaminophenyl)natutalide, and 3-(P-dimethylaminophenyl).
-3-(2-methylindol-3-yl)-6-dimethylamino-7-thallide and other acyl derivatives such as triallylmethane 7-thallide and methylene blue benzoyl, anizoyl, and pivaloyl; 3-diethylamino-
There are xanthine 7-thallides such as 6-methyl-7-chlorofluoran and 3-diethylamino-7-dibenzylaminofluoran, which are also used in the present invention.

Examples of high boiling point solvents include alkylnaphthalenes represented by diisopropylna-7talene, diallylakanes represented by 1-phenyl-1-xylylethane, alkyl biphenyls represented by isopropylbiphenyl, and other triallyl dimethanes. Aromatic hydrocarbons such as alkylbenzenes, benzylnaphthalenes, diallylalkylenes, and allylindanes; Carboxylic acid ester compounds such as diptyl phthalate and dioctyl maleate; Phosphoric acids such as tricresyl phosphate Ester compounds: include vegetable oils such as castor oil, soybean oil, and cottonseed oil, or modified oils thereof; and high-boiling fractions of natural products (consisting of aliphatic hydrocarbons) such as mineral oils, which are also used in the present invention.

Conventionally known color developers include acid clay, natural clay minerals such as attapulgite clay, and inorganic color developers.
Activated clay made by treating acid clay with mineral acid, JP-A-57-15
There are semi-synthetic solid acids described in Japanese Patent No. 996, and various phenolic compounds, novolak phenolic resins, aromatic carbonaceous polyvalent metal salts, etc. have been proposed and are already in use as organic color developers.

(C), #' Problems to be Solved by the Invention When these color developers are used as color developers in color developer sheets for pressure-sensitive recording materials, activated clay, which is an inorganic color developer, and semi-synthetic color developer Solid acids have excellent ink drying properties such as desensitized inks and plasticizer resistance of colored images, but they are inferior in color density and moisture resistance and light resistance of colored images, and furthermore, the background may yellow due to window element oxides. Change.

On the other hand, various phenolic compounds and novolak phenolic resins that are organic color developers have excellent moisture resistance of colored images, but the coloring speed is slow and the background is prone to yellowing. Polyvalent metal salts of aromatic carboxylic acids produce colored images with excellent moisture resistance and little yellowing of the background, but the rate of color development is slow.

By the way, recently proposed Japanese Patent Application Laid-Open No. 63-1867
The polyvalent metal compound of salicylic acid resin described in No. 29 and No. 63-254124 has an excellent coloring speed and little yellowing of the background.

However, like conventional organic color developers, there is a common problem in that the ink dries after printing with desensitized ink.

Desensitizing ink is used for the purpose of printing on a developer sheet coated with a color developer and preliminarily covering areas where color development is not required to prevent color development.

In desensitized ink printing methods, in offset and letterpress printing, drying of the ink is mainly achieved by one infiltration of the ink composition into the printing surface or paper, while in flexography and gravure printing, drying of the ink is achieved by one evaporation of the organic solvent in the ink. was achieved by.

However, if the ink drying is slow, the liquid substances in the ink composition, such as desensitizers and binders, are present in liquid form on the printed surface and in the paper, making it difficult to use the developer sheet with desensitized printing. While stacking, rolling up, or even storing as a set with a coloring agent sheet as a slip or office paper, the desensitizer may migrate (move) and destroy adjacent microcapsules, causing the need for coloring. Problems can be seen where color development is blocked or rendered impossible. That is, in desensitizing printing of pressure-sensitive recording materials used as image recording materials, the phenomenon of migration of the desensitizing ink, that is, slow ink drying, is a fundamental problem that is impractical. .

Therefore, the object of the present invention is to develop a color developer sheet using a polyvalent metal salt of an aromatic carboxylic acid that causes less yellowing among organic color developers, and a polyvalent metal compound of a salicylic acid resin that has an excellent color development rate. An object of the present invention is to provide a color developer sheet for pressure-sensitive recording materials, which has excellent desensitizing ink drying properties.

(E) Means for Solving Problem a As a result of intensive research and experiments, the inventors have developed a pressure-sensitive recording material made by a manufacturer in which the desensitizing ink dries quickly and the color development characteristics are not impaired. succeeded in developing a color developer sheet for

That is, the present inventors found that the color developer is an aromatic carboxylic acid polyvalent metal salt, and furthermore, the following general formula (1), [I[], [■] (wherein, B1, R2, and 几5 are respectively X independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aralkyl group, or an aryl group, and R+t and 几2 may be adjacent to each other to form a ring. It represents a bond or a linear or branched divalent hydrocarbon having 1 to 5 carbon atoms, and R4 and Rs represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aralkyl group, or an aryl group.

R6 is a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms) A polyvalent metallized salicylic acid resin having an average weight molecular weight of 500 to 10,000 is used as an organic heavy coloring agent,
By using sepiolite, a natural fibrous clay mineral, as the pigment to be mixed, the desensitized ink dries quickly, has excellent color development speed, and has minimal yellowing of the background.A developer sheet for pressure-sensitive recording materials. The present invention was developed based on the knowledge that aromatic carboxylic acid polyvalent metal salts as color developers used in the present invention are disclosed in Japanese Patent Publications Nos. 49-10856 and 51-2517.
4, No. 52-1327, No. 52-7372, etc., but for example, specifically,
Tolyl hydroxybenzoate, 4-hydroxybenzoic acid me-7enyl pendyl ester, m-xylylene bis4-
Hydroxybenzoic acid m ester, 4-hydroxybenzoic acid phenethyl, 4-hydroxybenzoic acid-p-cumylbenzyl, 4-hydroxybenzoic acid-cinnamyl ester,
4-Hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid-m-fluorobenzyl ester, 4-hydroxybenzoic acid-cumyl ester, 4,4'-hydroxy-21,2/-dibutylphenyl sulfone, β-phenethyl orseline F, cinnamyl orselinate, orselic acid-C-chlorophenoxyethyl ester, 5
．． 5'-methylenebis-2,4-dihydroxybenzyl acid benzyl ester, d-7z nylphenoxyethyl orselinate), m-phenylphenoxyethyl orselinate, 2,4-dihydroxybenzoic acid-β-3'-t
-Butyl-4'-hydroxyphenoxyethyl ester, bisphenol A and through-hydroxybenzoic acid ester, 5-β-methoxyphenoxyethoxy 2-
Hydroxybenzoic acid, 2.4-Dihydroxybenzoic acid 9-methylbenzyl ether, 2.4-dihydroxybenzoic acid-β-phenoxyethyl ester, 2.4-
Dihydroxy-6-methylbenzoic acid [Ω-methylbenzyl ester, bis-4-hydroxyphenylacetic acid phenoxyethyl ester, 4,4'-diacetyldiphenylurea, 3-phenylsalicylic acid, 5-p-α-methylbenzyl-a-methyl Benzyl salicylic acid, 5-p-methoxyphenoxyethyloxysalicylic acid, 5-phenoxyethoxysalicylic acid, 5-p-benzyl-a-methylbenzyl salicylic acid, 3-xylyl-5-(g,α-dimethylbenzyl)salicylic acid, 3t5z di( a-methylbenzyl)salicylic acid, 2-hydroxy-1-a-ethylbenzyl-3-su7toic acid, and the like. Calcium, magnesium, copper, zinc, tin, barium, cobalt, etc. are used as polyvalent metal salts, and zinc is particularly effective.

The polyvalent metal compound of salicylic acid resin as a color developer used in the present invention is disclosed in JP-A-63-186729 and JP-A-63-25.
For example, specifically, the following general formula [v] (wherein R1, R2, RA and 11/ are each independently a hydrogen atom, a carbon number of 1 to 12
represents an alkyl group, cycloalkyl group, aralkyl group, or aryl group, and R1 and R+2 may be adjacent to each other to form a ring.

x and x' are each independently a direct bond or a carbon number of 1 to 5
In the presence of a strong acid catalyst such as hydrochloric acid or sulfuric acid, a salicylic acid derivative represented by a straight chain or branched divalent hydrocarbon group (where n is 1 or 0) is added to the salicylic acid derivative represented by the following general formula CM) (wherein, R4 and R5 represent a hydrogen atom or a methyl group,
B4 represents a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms) is subjected to a Friedel-Crach reaction, and the resulting resin composition is mixed with polyvalent metal salts of calcium, magnesium, aluminum, and copper. , a salicylic acid resin polyvalent metal compound produced by reacting oxides, hydroxides, carbonates, and organic carboxylates such as zinc, tin, barium, cobalt, and nickel in an aqueous medium and/or by heating and melting; Furthermore, the salicylic acid derivative represented by the above general formula [■] is reacted with the following general formula [■] (wherein R4 and R5 are a hydrogen atom or an alkyl group having 1 to 12 carbon atoms) in the presence of a Friedelkraff catalyst. , represents an aralkyl group, an aryl group or a cycloalkyl group, and X represents a).rogen atom. This is a polyvalent metallized salicylic acid resin produced by reacting benzyl halides represented by ) and reacting the resulting resin composition with the above-mentioned polyvalent metal salts in the same manner. A particularly effective polyvalent metal is zinc.

The amount of the above styrene derivative used is 0.2 to 20 mol, preferably 0.5 to 10 mol, per 1 mol of the salicylic acid derivative.
It is a mole. The weight average molecular weight of the resin produced within this range of usage is 500 to 10,000.

Specific examples of polyvalent metallized salicylic acid resins produced by reacting with styrene derivatives used in the present invention include zinc salts of 3,5-di(4-methylbenzyl)salicylic acid resins produced by reacting with styrene; Zinc salt of 5-(4-methylbenzyl)salicylic acid resin produced by reacting σ-methylstyrene, 3- produced by reacting with styrene
Examples include zinc salt of phenylsalicylic acid resin.

The amount of the above benzyl halides used is 0.2 to 20 mol, preferably 0.5 to 20 mol, per 1 mol of the salicylic acid derivative.
It is 10 moles. The weight average molecular weight of the resin produced within this range of usage is 500 to 10,000.

Specifically, the salicylic acid resin polyvalent metal compound produced by reacting with benzyl halides used in the present invention is as follows:
3,5-di(
Zinc salt of 4-methylbenzyl) salicylic acid resin, 5-( produced by reacting .-monomethylbenzyl chloride)
α,α-dimethylbenzyl)? Zinc salt of lytic acid resin,
2.4-dimethylbenzyl chloride! Examples include zinc salt of 3-tert-butyl-5-phenylsalicylic acid resin produced by reaction.

The pigment mixed and used in the present invention is sepiolite, which is a natural fibrous clay mineral.

Sepiolite, a natural fibrous clay mineral, is mainly composed of hydrated magnesium silicate, and has a crystalline structure in which the cross section of a single fiber is stacked alternately with talc (magnesium silicate). Approximately 5.6X11. O
There are many long tunnels with diameter A. This tunnel has a unique adsorption effect, and its characteristics are pentonite)
Thixotropy represented by K, adsorption represented by zeolite,
It has the plasticity typical of kaolin.

Sepiolite, a natural fibrous clay mineral of the present invention, is
Although any organic color developer is effective, the polyvalent metal compound of salicylic acid resin exhibits particularly excellent effects.

Sepiolite, a natural fibrous clay mineral of the present invention, is
Used in combination with other pigments.

Examples of pigments include clay, kaolin, calcined kaolin, calcium carbonate, magnesium carbonate, satin white, titanium oxide, zinc oxide, urea resin, plastic pigment, alumina, and the like.

The content of sepiolite, which is a natural fibrous clay mineral, in the pigment is 3% by weight or more, particularly preferably 5% to 5% by weight.
50% by weight. If the amount is less than 3% by weight, no significant effect on the drying properties of the desensitized ink can be obtained.

Examples of the color developer and pigment binder used in the present invention include starch, phosphate ester, modified starch, cationized starch, starch derivatives such as dialdehyde starch, casein, gelatin, polyvinyl alcohol, methyl cellulose, Water-soluble polymers such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyederene oxide, polyvinylpyrrolidone, vinyl acetate maleic acid copolymer, styrene maleic anhydride copolymer, sodium polyacrylate, sodium alginate, polyacrylamide, styrene Examples include latex emulsion polymers, which are butadiene-based, acrylic-based, and vinyl acetate-based hydrophobic polymers.

In the present invention, a coating liquid for a color developer sheet is prepared together with a color developer, a pigment, a binder, and optionally an anti-dusting agent and an antifoaming agent. Depending on the application method, the absolute dry weight solid content is 1.5~
Apply 1517wl. Particularly preferred coating amount is 3 to 10
It is fltd.

(E) Function The color developer sheet of the present invention has excellent drying properties for desensitized ink, but considering this principle, it is found that natural Sepiolite, which is a fibrous clay mineral, was described above, and the cross section of a single fiber is approximately 5.6 x 11. There are many OA tunnels with long diameters, and the amount of oil absorbed is large.

This means that the oil base of the printed desensitizing ink! This is because most of the desensitizer contained in the coating layer is absorbed into the tunnels on the surface of the coating layer and easily penetrates.

(F) Examples Preferred embodiments and excellent effects of the present invention will be specifically explained below using the most typical examples. In addition, all parts below represent parts by weight.

Example 1 Method for preparing 25% color developer dispersion (A) 3.5 Zinc salt of di(a-methylbenzyl)salicylic acid 1
00 parts 10% polyvinyl alcohol aqueous solution 5
0 parts Disperse the above solution in a ball mill for 24 hours to obtain 25%
This was referred to as a color developer dispersion (A).

io* sodium hexametaphosphate 10 parts in 57 parts of water
Part addition, sepiolite (Showa mining layer, Milcon SP, fiber length 5.0μ, fiber diameter 0.1μ, oil absorption 150m/1G
Of) 3 parts, 47 parts of kaolin (M, made by Hieva, Hydrasperse), and 50 parts of calcium carbonate (Brilliant-15, made by Shiraishi Calcium) are added! After dispersion, 40 parts of the above 25% color developer dispersion (A), 100 parts of 10% oxidized starch aqueous solution (eclipse layer, M8-3800), 48%
25 parts of carboxylated styrene-butadiene copolymer latex (DL-620 manufactured by Syo Kasei Co., Ltd.) was added to prepare a coating liquid. This coating solution was coated on a high-quality paper with a basis weight of 40 f/7 ml using a blade coater so that the coating amount was 5 coats (absolutely dry solid content) and dried to prepare a color developer sheet.

Example 2゜15 parts of 10% sodium hexametaphosphate in 125 parts of water, 2.5 parts of 40eIb sodium polyacrylate, 10
After adding 100 parts of % oxidized fyP7 aqueous solution (MS-3800), adding 50 parts of sepiolite (Milcon 5P), 25 parts of kaolin (Hydrasperse), and 25 parts of calcium carbonate (Brilliant-15), and dispersing, 2 above
5% A colorant dispersion (A) 4.0 parts, 48% carboxylated styrene-butadiene copolymer latex (DL-6
20) 25 parts were added to prepare a coating liquid. This coating liquid was used in Example 1. The color developer sheet was prepared by applying and drying in the same manner as described above.

Example 3 Zinc salt of methylbenzyl salicylic acid resin 100
Part 10% polyvinyl alcohol aqueous solution 50
The above mixed solution was dispersed in a ball mill for 24 hours to obtain a 25% color developer dispersion (B).

Example 1. A developer sheet was prepared in the same manner except that the same amount of the 25-inch developer dispersion (A) was replaced with the 25-inch developer dispersion (B) as the coating liquid.

Example 4゜Example 2. A developer sheet was prepared in the same manner except that the 25 parts developer dispersion (A) was replaced with the same amount of 251 developer dispersion CB) as the coating solution.

Example 5 Zinc salt of di(4-methylbenzyl)salicylic acid resin 10
0 parts 10 Tivoli vinyl alcohol aqueous solution
50 parts of the above mixture was dispersed in a ball mill for 24 hours, and 25 parts
This was designated as qb colorant dispersion (C).

Example 1. A developer sheet was prepared in the same manner except that the same amount of the developer dispersion (A) yk was used as the coating solution.

Example 6゜Example 2. No25 q66 component dispersion (A)'r25%
A developer sheet was prepared in the same manner except that the same amount of the developer dispersion (C) was used as the coating solution.

Comparative example 1゜Example 1. A developer sheet was prepared in the same manner except that 3 parts of sepiolite was replaced with 3 parts of kaolin (hydrasperse) in the coating solution.

Comparative example 2゜Example 1. 3 parts of sepiolite was replaced with 3 parts of kaolin (Hydrasperse), and a 25% 8 colorant dispersion (A
A blood tint sheet was prepared in the same manner except that the same amount of 25 parts of developer dispersion (B) was used as the coating solution.

Comparative example 3゜Example 1. 3 parts of sepiolite was replaced with 3 parts of kaolin (Hydrasperse), and 25 parts of color developer dispersion (A
A developer sheet was prepared in the same manner except that the same amount of 25 parts of developer dispersion (C) was used as the coating solution.

Test/Measurement Method The prepared color developer sheet was subjected to Test I by the following method.
The results are shown in Table 1. It was shown to.

0 color development speed Color developer sheet was combined with commercially available Mitsubishi NCB paper blue coloring top paper (N-40) and passed through a calendar to develop color 1
After a few minutes, the color density was measured using a color difference meter, and the value shown below was determined as the color development rate. The smaller the number, the higher the color density.

Drying performance of 0 desensitizing ink Fuji photo offset ink (FN-103) desensitizing ink was printed on the Miyakoshi Seisakusho Miaster 18ffi printing machine with an amount of ink of 3. Place a weight of 50 lbs. on the color developer coated side of the color agent sheet, leave it for one week (at 25℃), then remove the weight, and remove the weight from the developer sheet before printing and the top paper for blue color development. The mixture was passed through a calendar to develop color, and the degree of color development and decolorization (area in contact with the ink) due to migration of the desensitized ink was measured using a color difference meter as shown below. The larger the number, the higher the ink drying performance (rate).

Part coloring reflectance (D) (G) Effect of the invention As is clear from the examples, among the organic color developers, the color developer of the present invention is a polyvalent metal salt of aromatic carboxylic acid, and the support is salicylic acid. A highly practical manufacturer that uses sepiolite, a natural fibrous clay mineral, as the pigment to be mixed with polyvalent metalized resins.The desensitized ink has excellent drying properties and does not impair color development speed. A color developer sheet for pressure-sensitive recording materials was obtained.

Claims (1)

[Claims] Manufacturer Hong pressure-sensitive recording materials comprising an electron-donating colorless (leuco) dye and an electron-accepting color developer capable of coloring the colorless (leuco) dye, the color developer is an organic color developer, and the colorless (leuco) dye is used as a pigment. Manufacturer Hong's color developer sheet for pressure-sensitive recording materials is characterized by containing sepiolite, a natural fibrous clay mineral.