JPS6018559A - Water-based ink - Google Patents

Abstract

PURPOSE:To provide a water-based ink resistant to spreading with water, etc., by using a base composed of an emulsion obtained by polymerizing a specific monomer, coloring the obtained fine polymer particles containing a specific amount of sulfonic acid group with a cationic dye, and dispersing the colored particles in water. CONSTITUTION:The objective water-based ink is obtained by (1) copolymerizing (A) an ethylenic unsaturated sulfonic acid or its salt (e.g. vinylsulfonic acid) and (B) other ethylenic unsaturated monomer capable of copolymerizing with the monomer A and giving polymer particles having an average particle diameter of <=1mu (e.g. acrylic acid ester) by emulsion polymerization method usually in the presence of water in a manner to produce copolymer particles containing >=2X 10<-5>g-equivalent per 1g of the polymer and having an average particle diameter of <=1mu, and (2) adding a cationic dye and optionally various other additives to the product to obtain colored polymer emulsion.

Description

[Detailed description of the invention] The present invention relates to a water-based ink based on fluoride.

More specifically, it relates to an aqueous ink based on an aqueous emulsion of colored polymer particles, in which polymer particles having an average particle diameter of 1 μm or less are dyed with a cationic dye and stably dispersed in water. It is.

BACKGROUND ART Conventionally, water-based inks have been known in which a water-soluble dye is dissolved in water and used as a coloring agent. These conventional water-based inks have the disadvantage that the recorded ink may smear due to water or sweat, or the printed area may disappear, since the dye is water-soluble.

On the other hand, JP-A No. 52-80340 states that acrylonitrile-based polymers with sulfonic acid groups introduced and dyed can be used for printing inks, etc. However, the above-mentioned drawbacks apply. Not only is it unclear to what extent this is eliminated, but also the polymerization must be carried out at a high temperature of 120° C. or higher and therefore under considerably high pressure.

The present inventors focused on such conventional problems, and created a polymer emulsion that can be produced at a relatively low temperature, and by coloring the fine polymer particles themselves, the polymer emulsion is The present invention was achieved through research into colored polymer emulsions that exhibit good transparency immediately upon drying of the emulsion and have film-forming ability at least at room temperature.

The present invention provides an ethylenically unsaturated sulfonic acid or a salt thereof;
By copolymerizing with this at a temperature below 100℃, the average particle size is 1μ.
A polymer obtained by polymerizing one or more of the following other ethylenically unsaturated monomers that can be depolymerized, wherein the polymer contains at least 2×1
Based on a polymer emulsion containing colored polymer particles dyed with a cationic dye, particles of a polymer having an average particle diameter of 1 μ or less into which sulfonic acid or its salt has been introduced in an amount of 0-' gram equivalent/gram polymer or more. It provides water-based ink.

The aqueous ink of the present invention contains an ethylenically unsaturated sulfonic acid or its salt and the other ethylenically unsaturated monomer,
In a system in which water is present in the range of 35 to 95 wt% based on the total amount of monomer and water, polymerization is carried out at a polymerization temperature of 100°C or less, and at least 2
It is obtained by adjusting the feed ratio of raw monomers so that sulfonic acid groups of 10-' gram equivalent/gram polymer or more are introduced, and adding a cationic dye to the resulting polymer emulsion.

In carrying out the present invention, examples of ethylenically unsaturated sulfonic acids or salts thereof include vinylsulfonic acid, allylsulfonic acid, and methallylsulfonic acid.

Styrene sulfonic acid, vinylbenzyl sulfonic acid.

Unsaturated sulfonic acids such as acryloyloxyethylsulfonic acid, methacroyloxypropylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and salts thereof, such as lithium salts.

Examples include sodium salts, potassium salts, ammonium salts, etc.

In the present invention, other ethylenically unsaturated monomers include acrylic esters, methacrylic esters, vinyl esters, and styrenes.

Olefins, amine groups, carboxyl groups.

It can be selected from hepatomers having hydrophilic functional groups such as amide groups and hydroxyl groups.

That is, examples of acrylic esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate.

Examples include 2-ethylhexyl acrylate and glycidyl acrylate. Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, and glycidyl methacrylate. Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl methoxy acetate + vinyl benzoate, and vinyl salicylate. Examples of styrenes include styrene,
Examples include methylstyrene and chlorstyrene. Olefins include butadiene, chlorobrene,
Examples include vinyl chloride and vinylidene chloride. Furthermore, monomers having hydrophilic functional groups include dimethylamine ethyl acrylate, dimethylaminoethyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, maleic acid, acrylamide, methacrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2-hydroxy Examples include propyl methacrylate.

By polymerizing these monomers in water, sulfonic acid or its salt can be introduced into the polymer particles. The method of polymerizing such ethylenically unsaturated sulfonic acid or its salt with other ethylenically unsaturated monomers may be the same as the commonly used emulsion polymerization method. Other ethylenically unsaturated monomer components that can be copolymerized with this are used, such as general polymerization initiators such as persulfates such as potassium persulfate and ammonium persulfate, or kiemene hydroperoxide and t-butyl hydroperoxide. It can be easily carried out by introducing each substance together with organic peroxide etc. all at once, partially or continuously into a polymerization vessel under stirring and reacting in water, but the polymerization temperature is 100°C or less. is sufficient. Further, surfactants used in ordinary emulsion polymerization may be present in the polymerization reaction system.

The average particle diameter of the polymer particles obtained by such a polymerization method depends on the amount of ethylenically unsaturated sulfonic acid or its salt used in the polymerization system, the amount of polymerization initiator used, the amount of water used, the polymerization temperature, etc. Ru. Basically, the particle size tends to decrease as the amount of ethylenically unsaturated sulfonic acid or its salt increases, the particle size tends to decrease as the amount of polymerization initiator increases, and the amount of water used As the amount decreases, the particle size tends to increase. In order to obtain a stable aqueous emulsion of colored polymer particles of the invention,
The average particle diameter of the polymer obtained by polymerization must be 1 μm or less, preferably 13 μm or less.

Also, more than 2 X 10-'5 gram equivalents/gram polymer, preferably more than 5 X 10-' gram equivalents/gram polymer, must be introduced into the polymer. Sulfo/acid groups This is because if the amount of sulfonic acid groups introduced into the polymer is too small, polymer aggregates will form, making it impossible to obtain fine polymer particles.On the other hand, if the amount of sulfonic acid groups introduced into the polymer is large, the polymer particles will become small. However, since the viscosity of the aqueous emulsion may become high, it is practical to keep the viscosity to below 1 x 10-3 gram equivalent/gram polymer, preferably below 5 x 10'' gram equivalent/gram polymer. In order to copolymerize ethylenically unsaturated sulfo/acid or its salt with other ethylenically unsaturated monomers copolymerizable with it so as to achieve such an introduction rate, the concentration of the former is usually α4 to 10 wt%.
, preferably from 1 to S Wt, and the latter to 10
The reaction may be carried out at ~60 wt%, preferably 50-55 wt%.

Next, there is a dyeing method for the fine particulate polymer obtained as an aqueous emulsion.
Cabionic dyes such as known cationic dyes and basic dyes such as azo-based, methine-based, oxazine-based, and anthraquinone-based dyes may be used.

Industrially, the easiest way to dye is to dye an emulsion of polymer particles with formic acid or acetic acid.

It can be carried out by a conventional dyeing method in which the pH is adjusted to 2 to 7, preferably 73 to 5, using an organic acid such as butyric acid, tartaric acid, or malic acid; or an inorganic acid such as hydrochloric acid or sulfuric acid, and then a dye is added. Note that such dyeing conditions are not limited in view of the spirit of the present invention.

The aqueous ink based on the colored polymer emulsion of the present invention has an extremely significant feature of directly forming a colored film upon drying, since the polymer particles in the emulsion are themselves colored. Therefore, when printing, recording, or writing, a water-insoluble colored thin film is formed, and the drawbacks of conventional water-based inks, such as smearing due to water or sweat or loss of printed areas, are completely eliminated. It will be resolved in .

Furthermore, the present invention improves the sunlight fastness of basic dyes and cationic dyes, which have conventionally been characterized by excellent color clarity and whose only drawback has been low sunlight fastness.
It was discovered that the quality could be improved by dyeing with a polymer.

Therefore, a second advantage of the present invention is that it provides a water-based ink with vivid colors and improved sunlight fastness.

The aqueous ink of the present invention having such characteristics itself:
Although it can be used as an aqueous ink, various additives normally used in aqueous inks, such as ink drying regulators and preservatives, may also be added.

EXAMPLES The present invention will be described in more detail by way of Examples below, but the scope of the present invention is not limited in any way by the description of these Examples. In the examples, parts and percentages are by weight unless otherwise specified.

The amount of sulfonic acid groups was determined by quantifying sulfur using the combustion method. The average particle diameter was measured by a turbidity method. The sunlight fastness was determined by coating art paper with a colored emulsion adjusted to z o wt% using a 1 mil doctor blade and drying it at room temperature. Black panel temperature 6
Blue scale (5°C ± 3°C) for 48 hours test
JIS method).

Example-1 Emulgen 20C (
1.09 (manufactured by Kao Atlas Co., Ltd.) and 65 g of water were added, stirred while flowing nitrogen gas, and heated to 60°C. Styrene 4α59. A monomer mixture containing 6 parts and 5 g of n-butyl acrylate; Spinomer Na58 (Toyo Soda sodium p-styrene sulfonate purity 82.0%) 3
An aqueous solution of sodium p-styrenesulfonate in which 7 g was dissolved in 759 g of water; and ammonium persulfate [15 g in 4 g of water
An aqueous solution of a polymerization initiator dissolved in 0.09 was added over a period of 3 hours, and polymerization was carried out at 60°C. After the addition of each liquid was completed, the polymerization temperature was maintained for an additional 2 hours.

The average particle diameter of the polymer particles in the obtained polymer emulsion was approximately (110μ).Also, there was t4 in the polymer.
X10'' gram equivalent/gram of sulfonic acid groups were contained. 110° of polymer emulsion
The evaporation residue at C was 37.0%.

Next, the resin content of the obtained polymer emulsion was 100
Cationic dye (Kanalon Blue 50LH, Cachilon Yellow T-RLH, Methylene Blue FZ, Methyl Nog Iolet Pure, all manufactured by Hodogaya Chemical) 1
．． 5 parts of water, 10 parts of water, and 1.0 part of 50 thiacetic acid aqueous solution were added thereto, and the mixture was stirred at 95°C to 98°C for 1 hour, and then cooled to room temperature.

When a portion of the colored polymer emulsion thus obtained was cast onto a glass casting plate and left in a thermostatic chamber at 25°C, transparent, clear, and flexible films were obtained. .

The colored polymer emulsion thus obtained is impregnated into a felt-tip pen to create art paper and Kent paper.

I was able to draw letters on craft paper, etc. The dried characters exhibited excellent water resistance, and no phenomena such as bleeding or ink loss due to immersion in water were observed.

Furthermore, the sunlight fastness of each dye itself was below grade 1 on the blue scale, but that of the above-mentioned colored emulsion was grade 3 to 4.

Example 2 The following ingredients were added to a 500 d flask that had been purged with nitrogen, and the temperature was raised to 40°C without flowing nitrogen gas.

A monomer mixture containing 50 g of methacrylic acid and 1 g of methacrylic acid; an aqueous sodium p-styrene sulfonate solution in which 2.5 g of Spinomer Na58 (sodium p-styrene sulfonate purity 82.0 tIJ manufactured by Toyo Soda) was dissolved in 47.5 F of water; Ammonium persulfate 0.59 to water 49.
59 and an aqueous solution of ammonium persulfate dissolved in each were added over a period of 3 hours and polymerized at 40°C. After the addition of each solution, the polymerization temperature was maintained for an additional 5 hours.

The average particle diameter of the polymer particles in the obtained polymer emulsion was approximately α11μ. Also, in the polymer there is 1.2
X10 contained the most gram equivalent/gram polymer of sulfonic acid groups. 110℃ of polymer emulsion
The evaporation residue was 41.1%. Next, cationic dyes (Catilon Red GLM, Cachilon Red 6BH) were added to 100 parts of the resin of the obtained polymer emulsion.
, Cachilon Yellow aLH, both manufactured by Hodogaya Chemical) 1
．． After adding 0 parts of water, 10 parts of water, and 1 part of acetic acid, the mixture was stirred at 98°C for 60 minutes and then cooled to room temperature.

! A portion of the colored polymer emulsion prepared above was cast onto a glass casting plate and left to stand at room temperature (25°C to 28°C), resulting in transparent, clear, and flexible colored films.

A 7jl-rutoben was produced in the same manner as in Example 1, and a good feltben was obtained without any scratches or clogging. Furthermore, the dried letters showed excellent water resistance, and no bleeding or washing-off was observed even when immersed in tap water. The sunlight fastness of all the colored emulsions was 4 to 5 on the blue scale.

The dyes themselves were all below grade 1.

Example 5 The following ingredients were added to a flask purged with nitrogen, and the temperature was raised to 40° C. while flowing nitrogen gas.

Next, methyl methacrylate) 559. Ethyl acrylate 659. Monomer mixture containing 1.0 g of acrylic acid; 50 g of potassium p-styrene sulfonate mixed with 479 g of water
An aqueous solution of potassium p-styrenesulfonate dissolved in a solution of potassium p-styrene sulfonate; and an aqueous solution of potassium persulfate (aqueous solution of potassium persulfate in which L5 was dissolved in 495 g of water) were each added over 3 hours and polymerized at 40°C. After addition of each solution, an additional 2. The polymerization temperature was maintained for an hour.

The average particle diameter of the polymer particles of the obtained polymer emulsion was [1L08μ, and the evaporation residue of 110”C was 41.
It was 2%. Also, 1.4 x 10'''4 in the polymer
Gram equivalents/gram polymer of sulfonic acid groups were contained.

Then, the resin content of the obtained polymer emulsion was 100
Cationic dye (Canalon Yellow 5GLH,
Kachiron Red GL) 1. 2.0 parts of malachite green (all manufactured by Hodogaya Chemical), 20 parts of water, and 5 parts of acetic acid (L) were added, dyed at 95°C to 98°C for 60 minutes, and then cooled to room temperature.

When each colored polymer emulsion was cast onto a glass casting plate and left at room temperature in the same manner as in Example 1, a clear, flexible and brightly colored film was obtained. The film sections were each immersed in a 1:1 acetone/water mixture for one week, but no dye was observed to elute from any of the films.

By impregnating felt-tip pens with colored polymer emulsions, characters could be drawn on paper, cloth, and boards.

The sunlight fastness of the above dye itself was below blue scale grade 1, but that of the above emulsion was grade 3.
It was grade 5.

Patent Applicant: Toyo Soda Kogyo Co., Ltd. Procedural Amendment September 5, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1 Display of Case 1989 Patent Application No. 125463 2 Name of Invention Water-based Ink 3 Case of Person Making Amendment Relationship with Patent applicant telephone number (5s513ro11 Date of 4th amendment order Number of inventions increased by 5th amendment 0 ・-゛ I,,+
,, -1 6th amendment target specification; 7th amendment content specification engraving (no change in content) Procedural amendment June 15, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi Tono Indication of case 1 1988 patent Application No. 125463 2 Name of the invention Water-based ink 6 Relationship with the person making the amendment Patent applicant telephone number (585) 3511 6 Subject of the amendment ``Details of the invention in the description of the written amendment dated September 5, 1988 7. Between the 6th and 7th lines of page 10 of the specification of contents of the amendment, ``Also, the aqueous ink of the present invention may be written on acidic paper such as carbonless paper. It provides ink that is chemically stable and does not change color or fade.''

Claims (1)

[Scope of Claims] +11 (a) Ethylenically unsaturated sulfonic acid or its salt; and other ethylenic acid which can be copolymerized with this at a temperature of 100°C or less to produce a polymer having an average particle size of 1 μm or less Copolymer particles with an unsaturated monomer, comprising (a) copolymer particles having an average particle size of 1 μ or less with sulfonic acid groups 2×10-gram equivalents/gram polymer or more, and (b) a polymer dyed with a cationic dye. A water-based ink based on a colored polymer emulsion containing particles.