JPH02162089A - Developer composition for pressure-sensitive copying paper - Google Patents

Abstract

PURPOSE:To improve pasting property from the surface of a developing sheet coated with a developer composition by containing specific quantities of copolymer latex as adhesives and a surface-active agent. CONSTITUTION:A developer composition for pressure-sensitive copying paper mainly comprises a pigment for paper to be coated, a developer and adhesives. 3.2-15pts.wt. surface-active agent is included to 100pts.wt. copolymer latex as adhesives in solid conversion. Clay, calcium carbonate, aluminum hydroxide, etc. can be used as the pigment for paper to be coated. A phenol resin, a salicylic acid derivative, activated clay, etc., can be employed as the developer. Water- soluble high molecular adhesives, etc., are cited besides copolymer latex such as butadiene group latex, vinyl acetate group latex, etc., as the adhesives, and copolymer latex is particularly preferable in the adhesives. The effect of pasting property is reduced when the usage of the surface-active agent is less than 3.2pts.wt. to 100pts.wt. copolymer latex as the adhesives in solid conversion, and the water resistance of the surface of the developing sheet is deteriorated when the usage of the surface-active agent exceeds 15pts.wt.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a color developer composition for pressure-sensitive copying paper, and more particularly to a color developer composition for pressure-sensitive copying paper that has improved spine suitability. Regarding.

[Conventional technology]

Many pressure-sensitive copying papers have been proposed in the past, and these pressure-sensitive copying papers usually contain microcapsules containing an electron-donating colorless organic compound and a high-boiling organic solvent, a capsule protectant, and an adhesive as essential components. A color developer whose essential components are a color developer composed of an electron-accepting acidic substance that develops color from the electron-donating colorless organic compound, an inorganic pigment, and an adhesive. It is used in combination with a base paper made by applying the agent composition to the surface of the paper.

In addition, there is an inner paper coated with each composition on the back and front sides, and when a large number of copies are required, the inner paper is inserted between the upper paper and the lower paper. .

By the way, in this way, the combination of the upper paper and the lower paper,
Alternatively, when creating a slip, for example, which consists of a set of multiple sheets consisting of a combination of top paper, middle paper, and bottom paper, apply spine glue to the cut surface of the pressure-sensitive copy paper, and apply glue to the necessary sets. attached, and the sets are separated without being glued,
Only the set of slips can be taken out easily.

This characteristic is called back-gluing suitability for gluing.

In the pressure-sensitive copying paper industry, this ability to adhere to spines is important, but there are many problems such as weak adhesive strength within a set and adhesive sticking between sets, so improvements have been desired. .

Up until now, improvements have been made mainly to improve back fit in order to improve back fit. For example, Japanese Patent Publication No. 507634,
Special Publication No. 53-12847, Special Publication No. 53-1284
Publication No. 6, Special Publication No. 5312845, Special Publication No. 53-
Publications such as No. 12844 have been studied from the perspective of backsliding.

In addition, JP-A No. 57-70962 discloses improvements from the coloring sheet surface, JP-A No. 58-59889 discloses improvements from the non-coated surface, and JP-A No. 6343238 discloses improvements from the non-coated surface.
Improvements using wax emulsions have been considered, but these techniques have not yet yielded satisfactory results.

[Problems to be Solved by the Invention] The present invention has been made against the background of the above-mentioned problems of the prior art. An object of the present invention is to provide a color developer composition for paper.

[Means to solve the problem]

The present invention provides a color developer composition for pressure-sensitive copying paper containing a pigment for coated paper, a color developer, and an adhesive as main components, in which the amount of copolymer latex as the adhesive is 100 parts by weight in terms of solid content. On the other hand, the present invention provides a color developer composition for pressure-sensitive copying paper, which contains 3.2 to 15 parts by weight of a surfactant.

The coated paper pigments used in the composition of the present invention include clay,
Those commonly used in coated paper compositions can be used, such as calcium carbonate, barium sulfate, titanium oxide, satin white, and aluminum hydroxide.

Further, as the color developer used in the composition of the present invention, those normally used as a color developer for pressure-sensitive copying paper, such as phenol resin, salicylic acid derivatives, polycarboxylic acids, and activated clay, can be used.

The amount of the color developer used is usually 10 to 30 parts by weight, preferably 15 to 30 parts by weight, based on 100 parts by weight of the pigment for coated paper.
About 17 parts by weight is used.

Furthermore, the adhesive used in the composition of the present invention includes:
In addition to copolymer latex such as butadiene latex, acrylic latex, and vinyl acetate latex, water-soluble polymer adhesives such as starch, casein, and polyvinyl alcohol can be used singly or in combination of two or more. be able to.

Among the adhesives mentioned above, copolymer latex is particularly preferred. This copolymer latex contains (a) 25 to 60% by weight of aliphatic conjugated diolefin, (b) 2 to 15% by weight of ethylenically unsaturated carboxylic acid, and (C) ethylenic inorganic acid other than component (b). Particularly preferred is a copolymer latex obtained by copolymerizing 25 to 73% by weight of saturated monomers ((a)+(b)+(C)=100% by weight).

Among these, specific examples of (a) aliphatic conjugated diolefin include 1,3-butadiene, 2-methyl-1゜3-butadiene, 2-chloro-1,3-ph9'; and these can also be used in combination.

When the proportion of this (a) aliphatic conjugated diolefin is less than 25% by weight or more than 60% by weight,
This is not preferred because the pigment binding ability of the copolymer latex is reduced.

Further, as the ethylenically unsaturated carboxylic acid (b), for example, mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, fumaric acid, and itaconic acid are used, and these can also be used in combination. This (b)
If the proportion of ethylenically unsaturated carboxylic acid is less than 2% by weight, it is undesirable because the viscosity stability and mechanical stability of the resulting composition will decrease, and the surface strength of the resulting coated paper will decrease. If it exceeds 15% by weight, the viscosity of the composition increases, resulting in a decrease in workability, and furthermore, the surface strength of the coated paper obtained also decreases, which is not preferable.

Furthermore, (C) the ethylenically unsaturated monomer other than the component (b) is another monomer copolymerizable with the components (a) to (b), such as styrene, α-methyl Styrene, p-methylstyrene, vinyltoluene (o-5m
Aromatic vinyl compounds such as -1 p-methylstyrene mixture; methyl acrylate, methyl methacrylate, 2-
Acrylic acid or methacrylic acid esters such as hydroxyethyl methacrylate; other examples include acrylamide, methacrylamide, acrylonitrile, and the like.

In the present invention, the amount of the adhesive, particularly the copolymer latex used, is usually about 5 to 20 parts by weight based on 100 parts by weight of the pigment for coated paper in terms of solid content.

In the present invention, a copolymer latex as an adhesive is added to the color developer composition for pressure-sensitive copying paper, which contains the pigment for coated paper, a color developer, and an adhesive as main components, in an amount of 100% in terms of solid content.
The major feature is that the surfactant is contained in an amount of 3.2 to 15 parts by weight, preferably 3.2 to 10 parts by weight.

Here, the surfactant used in the present invention includes various surfactants such as anionic, nonionic, amphoteric and cationic surfactants.

Among these, examples of anionic surfactants include higher alcohol sulfate esters, alkylbenzene sulfonates, aliphatic sulfonates, and the like. Further, as the nonionic surfactant, ordinary alkyl ester type, alkyl ether type, alkylphenyl ether type, etc. of polyethylene glycol are used. moreover,
Examples of amphoteric surfactants include those having carboxylates, sulfate ester salts, sulfonates, and phosphate esters as anionic moieties, and amine salts and quaternary ammonium salts as cationic moieties. Betaine salts include laurylbetaine, stearylbetaine,
The salts of cocoamidopropyl betaine and 2-undecyl-hydroxyethylimidazolium betaine are amino acid types such as lauryl-β-alanine, stearyl-β-alanine, and lauryl di(aminoethyl).
Examples include salts of glycine, octyldi(aminoethyl)glycine, and dioctyldi(aminoethyl)glycine. Furthermore, examples of the cationic surfactant include laurylamine acetate, polyoxyethylene laurylamine, and stearyltrimethylammonium chloride. These surfactants can be used alone or in combination of two or more.

Among these surfactants, preferred compositions include the following (a) to (d).

(a) The content of anionic surfactant in all surfactants is preferably 20% by weight or more, more preferably 40% by weight or more.
Items with a weight of 4% or more.

(b) The content of the sulfonate surfactant in the total surfactant is preferably 20% by weight or more, more preferably 40% by weight or more.

(c) The content of the sulfosuccinate salt surfactant in the total surfactant is preferably 20% by weight or more, more preferably 40% by weight or more.

(d) The content of the dialkyl sulfosuccinate salt surfactant in the total surfactant is preferably 20% by weight.
above, more preferably 40% by weight or more.

Among the above combinations, a color developer composition for pressure-sensitive copying paper which is preferred according to the order of (a) → (b) → (c) → (d) and which has even better spine suitability is the object of the present invention. can get.

The amount of the surfactant used in the composition of the present invention is:
The amount of the copolymer latex used as the adhesive is 362 to 15 parts by weight, preferably 3.2 to 10 parts by weight, based on 100 parts by weight of the copolymer latex as the adhesive, and if it is less than 3.2 parts by weight, the effect of back-stick suitability may be reduced. On the other hand, if it exceeds 15 parts by weight, the water resistance of the color developer sheet surface will deteriorate, which is not preferable.

When obtaining the composition of the present invention, the surfactant may be used, for example, when copolymerizing the copolymer latex as an adhesive, or after mixing the copolymer latex and the surfactant. , this mixture may be added to the pigment dispersion, or the copolymer latex and surfactant may be added separately to the pigment dispersion.

The composition of the present invention may contain conventional additives such as a dispersant, a viscosity modifier, a water retention agent, a water resistance agent, a dye, an antifoaming agent, and a preservative, if necessary.

The color developer composition for pressure-sensitive copying paper of the present invention is usually adjusted to a concentration of about 35 to 55% by weight in terms of solid content, and is applied to paper by air knife coating, blade coating, roll coating, etc. The resulting coated paper is used as a color developer sheet.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the examples, parts and % mean parts by weight and % by weight unless otherwise specified.

Examples 1 to 5 and Comparative Examples 1 to 2 In an autoclave purged with nitrogen gas, 40 parts of 1°3-butadiene, 46 parts of styrene, 10 parts of methyl methacrylate, and 3 parts of methacrylic acid were added. 1 part of itaconic acid, 1 part of ammonium persulfate, 2 parts of sodium dodecylbenzenesulfonate, 2 parts of sodium dioctyl sulfosuccinate, 2.5 parts of carbon tetrachloride and 200 parts of deionized water.
When reacted at 70'C for 15 hours, the polymerization rate was 99%.
reached. The resulting copolymer latex was adjusted to pH 6.5 with sodium hydroxide, and then steam was blown thereinto to remove residual supernatant. This copolymer latex is referred to as copolymer latex A.

Further, when polymerization was carried out under the same polymerization conditions as for copolymer latex A, using only 2 parts of sodium dodecylbenzenesulfonate as an emulsifier and without using sodium dioctylsulfosuccinate, a polymerization rate of 98% was reached. After adjusting the pH of this to 6.5 in the same manner as Copolymer Latex A, the residual upper layer was removed to obtain Copolymer Latex B.

Furthermore, 3 parts of sodium dioctyl sulfosuccinate was stirred and mixed with 100 parts of copolymer latex B to obtain copolymer latex C.

Using the copolymer latex A-C obtained in the above-mentioned manner for the sheet, it was coated on high-quality paper at a rate of 42 g/board according to the formulation shown in Table 1 to obtain a color developing sheet.

The color developing sheet obtained in this way and commercially available paper are
200 sheets of each were stacked alternately to make 200 sets, which were cut with a guillotine cutter.

For this cut surface, apply commercially available latex "Polysol"
(manufactured by Polymer ■, acrylic emulsion) was applied, and after drying, the adhesiveness of the adhesive and the water resistance were evaluated.

Here, the suitability for riding on the back and the water resistance were evaluated as follows.

The copy paper between and within the set was peeled off by hand, and the roughness between the sets was evaluated for ease, and the adhesion within the set was evaluated for strength.

○: Adhesion between the upper paper and the lower paper is sufficient.

×: The upper paper and the lower paper were easily peeled off and the adhesion was insufficient.

■Using Kidate R1-1 type printing test machine and IPI ink #4,
After applying dampening water with a Molton roll, printing was performed, and the state of picking that occurred was visually observed.

O; Good ×；Poor The results are shown in Table 1.

As is clear from Table 1, the color developer compositions of the present invention (Examples 1 to 5) all have excellent effects, and have excellent backing properties and can be used as color developer sheets. I was able to get it.

On the other hand, Comparative Example 1, which has a small content of surfactant, has poor back-stick suitability. Furthermore, it can be seen that Comparison 4jl) 2, in which the surfactant content was too high, was inferior in water resistance.

(The following is a blank space) [Effects of the Invention] The present invention is a color developer composition containing a specific amount of a surfactant, and is a pressure-sensitive copying paper that has further improved spine suitability compared to conventionally known improvement methods. is obtained.

Patent applicant: Japan Synthetic Rubber Co., Ltd. Agent Patent Attorney Takashi Shirai

Claims (1)

[Claims] (1) In a color developer composition for pressure-sensitive copying paper containing a pigment for coated paper, a color developer, and an adhesive as main components, copolymer latex as an adhesive is added to 100 parts by weight in terms of solid content. A color developer composition for pressure-sensitive copying paper, characterized in that it contains 3.2 to 15 parts by weight of a surfactant.