JPS60202167A - Water based ink composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which has excellent solubility and resistance to water and light and gives a deep color, consisting of a soln. in a solvent mixture of water and a water-soluble org. solvent of a colored polymer which is made water-insoluble by dyeing a specified water-soluble polymer with a basic dye. CONSTITUTION:A water ink compsn. consists of a soln. in a solvent mixture of water and a water-soluble org. solvent of, e.g., formula I (wherein R1 is H, CH3; R2, R3 are each H, CH3, C2H5) or II (wherein R4 is H, CH3; X is NH, NCH3, O; Y is CH2, O) of a colored polymer which is made water-insoluble by dyeing a water-soluble polymer contg. hydroxyl groups in a quantity of 1X10<-3> gram equivalents/gram of polymer or above and sulfo groups in a quantity of 1X10<-4> gram equivalents/gram of polymer or above [e.g. a hydroxyethyl acrylate/vinylsulfonic acid/(meth)acrylamide copolymer], with a basic dye. The compsn. has excellent solubility and resistance fo water and light. When the content of the sulfo group in the polymer is increased, a larger quantity of the basic dye can be dyed and a water based ink having a deep color can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to pigmented polymer-based aqueous ink compositions. More specifically, the present invention relates to an aqueous ink composition comprising a colored polymer obtained by dyeing a water-soluble polymer containing a hydroxyl group and a sulfonic acid group with a basic dye and a water-soluble organic solvent.

Conventionally, water-based inks have been known in which water-based dyes, such as direct dyes, acid dyes, and basic dyes, are dissolved in water, and wetting agents, preservatives, etc. are added. Therefore, when the recorded ink comes into contact with water or a damp object, it easily dissolves, causing the printed area to smear, become smeared, become unclear, and have poor water resistance.

In addition, water-based inks using basic dyes have superior advantages over water-based inks using direct dyes and acid dyes, such as a richer color range, two-color clarity, and a darker color per weight unit. On the other hand, it has drawbacks such as poor weather resistance and limited solubility, and its range of use is extremely limited.

The present inventor conducted research with the aim of providing an excellent ink composition by eliminating the drawbacks of the water resistance of water-based inks using the above-mentioned water-based dyes and the light resistance and solubility of basic dyes.
A water-based ink composition consisting of a colored polymer obtained by dyeing a water-soluble polymer containing hydroxyl groups and sulfonic acid groups with a basic dye and a water-soluble organic solvent has water resistance,
They discovered that it has excellent light resistance and solubility, and completed the present invention.

That is, the present invention provides hydroxyl groups in the polymer of I x 10-8 gram equivalents/gram polymer or more and
To provide an aqueous ink composition comprising a water-insoluble colored polymer obtained by dyeing a water-soluble polymer containing one sulfonic acid group with a basic dye of 10 = Durham equivalent/gram polymer or more and a water-soluble organic solvent. It is in.

In the present invention, a water-insoluble colored polymer is obtained by dyeing a water-soluble polymer containing a hydroxyl group and a sulfonic acid group with a basic dye using a commonly used dyeing method. This can basically be achieved by adding a water-soluble organic solvent before or after dyeing to dissolve the colored polymer in water.

It is not theoretically clear why the colored polymer of the present invention is insoluble in water, but the sulfonic acid groups in the water-soluble polymer and the basic dye are ionicly bonded to become hydrophobic, and most of the sulfonic acid groups are It is thought that when ionically bonded with a basic dye, it becomes a water-insoluble colored polymer. On the other hand, the obtained colored polymer has a hydroxyl group and an ionic bonding group in the polymer, so it has excellent affinity with water, and even if it is water-insoluble, it requires a relatively small amount of water-soluble organic solvent. It is assumed that it can be dissolved in water.

Based on these facts, the aqueous ink composition of the present invention has excellent water resistance because it uses a water-insoluble colored polymer as a base material, and also has excellent light resistance because the basic dye is ionically bonded to the sulfonic acid group in the polymer. It is considered to have excellent properties and solubility. Furthermore, by increasing the content of sulfonic acid groups in the polymer, it is possible to dye with an amount of basic dye that was previously unobtainable, and a deep-colored aqueous ink can be obtained.

For the water-soluble polymer containing hydroxyl groups and sulfonic acid groups used in the present invention, a method in which hydroxyl groups and sulfonic acid groups are introduced later into a pre-produced polymer is also adopted, but generally these monomers and other A method is employed in which a vinyl monomer capable of radical polymerization is polymerized.

Examples of radically polymerizable vinyl monomers containing hydroxyl groups include hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate,
Examples include polyethylene glycol monomethacrylate, methylol acrylamide, methylol methacrylamide, and the like.

Examples of the radically polymerizable vinyl monomer containing a sulfonic acid group include vinyl sulfonic acid, allyl sulfonic acid, and methallyl sulfonic acid.

Unsaturated sulfonic acids such as acrylamide methylpropanesulfonic acid, styrenesulfonic acid, vinylbenzylsulfonic acid, acroyloxyethylsulfonic acid, methacroyloxyethylsulfonic acid, and salts thereof, such as lithium salt, sodium salt, potassium salt, ammonium salt Examples include salt.

Furthermore, other vinyl monomers that can be radically polymerized with the above-mentioned bitroxyl group- and sulfonic acid group-containing monomers include hydrophilic vinyl monomers such as acrylamide, methacrylamide, aminoethyl acrylate-aminoethyl methacrylate, methyl acrylate, ethyl acrylate, etc. acrylate, propyl acrylate, butyl acrylate,
Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, vinyl acetate, acrylonitrile, methacrylonitrile.

Although hydrophobic vinyl monomers such as styrene can be used, the composition must be such that even when hydrophobic monomers are used, the resulting polymer is water-soluble.

Next, there is a polymerization method for obtaining a water-soluble polymer by polymerizing these monomers. For example, in a solvent such as water, 1
This can be easily carried out by introducing each monomer at once, partially or continuously into a polymerization vessel together with a conventional radical polymerization initiator at a polymerization temperature of 00° C. or lower.

The radical polymerization initiator used may be, for example, a persulfate such as potassium persulfate or ammonium persulfate, or an organic peroxide such as kiemene hydroperoxide or t-butyl hydroperoxide. Further, redox initiators used in combination with reducing agents such as acidic sulfites and ferrous sulfates can also be used.

The molecular weight of the resulting water-soluble polymer depends on the concentration of each hexamer present in the polymerization system, the amount of radical polymerization initiator used, the polymerization temperature, and other factors.

The monomer concentration can be selected arbitrarily, but is generally 5 to 5.
It can be implemented at 0%. Polymerization at high concentrations is not preferred because the viscosity of the polymerization system becomes high and it becomes difficult to remove the heat of polymerization. Furthermore, polymerization at low concentrations is not preferred for economic reasons. When the amount of the radical polymerization initiator used is increased, the molecular weight of the water-soluble polymer tends to decrease, and when it is decreased, the molecular weight of the water-soluble polymer tends to increase.

The molecular weight of the water-soluble polymer containing hydroxyl groups and sulfonic acid groups thus obtained is an important factor as it affects the viscosity of the water-based ink, but the average molecular weight is 5.
It may be less than X 105, preferably less than 1X10''.

In the present invention, the amount of hydroxyl groups and sulfonic acid groups contained in the water-soluble polymer obtained by the above polymerization method etc. determines the water resistance of the ink.

In view of light resistance, solubility, viscosity stability, etc., the hydroxyl group is at least I x 10 = 8 gram equivalents/gram polymer, preferably 3 x 10-'' gram equivalents/gram polymer or more, and the content of sulfonic acid groups is 1
x 10' gram equivalents/gram polymer, substantially 2 x 10-4 gram equivalents/gram polymer, 3
If the content is not more than X10-3 gram equivalent/gram polymer, satisfactory physical properties can be obtained as a base material for the aqueous ink composition of the present invention. When the content of hydroxyl groups is low, the amount of water-soluble organic solvent used increases, resulting in ink bleeding.

Problems such as set-off may occur, which is undesirable. On the other hand, if the content of sulfonic acid groups is low, not only the ink concentration will be low but also the viscosity stability of the ink will be poor.

On the other hand, if the amount is too large, the light resistance of the ink deteriorates, which is not preferable.

For the purpose of the present invention, the method of obtaining such a water-soluble polymer is not limited.

Next, as basic dyes for dyeing the obtained water-soluble polymer containing hydroxyl groups and sulfonic acid groups, usual triphenylmethane-based and azo-based dyes are used.

Basic dyes and cationic dyes classified in the Dye Handbook (edited by the Organic Synthetic Chemistry Association, published by Maruzen Co., Ltd.) are used as dyes known as methine, oxazine, and anthraquinone dyes. That is, the "basic dye" of the present invention also means a cationic dye.

For example, for yellows, 0, ko, (abbreviation for Oolor Txr6ax) basic yellow 110, ko, basic yellow 130. and basic yellow 14 # 19 tt 21 # 25 # 28 32 # 36 67 p 73.

For example, for orange color, C1 work, basic orange 150. and Basic Orange 21# 22 32 p 55 34.

For example, 0. Engineering, Basic Red 9 0. Engineering, Basic Red 1314 〃 15 18 23 /F 24 p 27 # 29 56 # 38 46 0, Engineering, Basic Red 10. 7 # 10 14 y 15 // 21 /' 25 # 27 〃28 etc.

For example, in the blue color, 0, engineering, basic blue A/-1'o, engineering, basic blue 3〃5〃7 9 〃 21 p 22 p 25 tt 26 # 41 44 p 45 0, engineering, basic blue 47 0. Basic Blue 64tt 65 #129, etc.

For example, for green, 0, engineering, basic green 1 0. Examples include engineering, basic green 4, 6, etc.

For example, black is O1■, basic black is 20. and basic black 8.

Such basic dyes are dyed through ionic bonds with sulfonic acid groups of water-soluble polymers to give colored polymers. The dyeing method is to dye a water-soluble polymer containing a human tetraxyl group and a sulfonic acid group with an organic acid such as formic acid, acetic acid, butyric acid, tartaric acid, malic acid, or hydrochloric acid.
It can be carried out by adjusting the pI (in the range of 2 to 7) using an inorganic acid such as sulfuric acid or an aqueous solution such as sodium hydroxide or sodium carbonate, and then adding a dye solution.
At this time, for example, the aqueous ink composition of the present invention can be obtained by adding a water-soluble organic solvent shown in the following general io] or [II] before or after dyeing.

General formula (1) % formula represents % or so. ) (II) Examples of the water-soluble organic solvent represented by the general formula (I) include formamide, N-methylformamide, NN'-
Examples include dimethylformamide, NN'-diethylformamide, acetamide, N-methylacetamide, dimethylsulfoxide, and the like.

As the water-soluble organic thinning represented by general formula (II),
For example, ethylene carbonate, propylene carbonate, γ=nibutyrolactone γ-methylbutyrolactone, 2
-pyrrolidone, N-methyl-2-pyrrolidone, 1.3-
Examples include dimethylimidazolidian. The amount of water-soluble organic solvent used is usually 5 to 50 wt%, preferably 10
~40 wt% is sufficient.

If a large amount of water-soluble organic solvent is used, the ink will bleed.

Problems such as set-off occur, which is not desirable.

For the purposes of the present invention, such dyeing methods are not limited.

The aqueous ink composition of the present invention can be used as an aqueous ink by itself, but if necessary, adjuvants commonly used in aqueous inks may be added, such as ethylene glycol, tetrapyrene glycol, diethylene glycol, polyethylene glycol, glycerin. , wetting agents such as triethanolamine, phenol, paraoxybenzoic acid alkyl esters, sodium omazine, antifungal agents or rust inhibitors such as dioxin, surfactants, and the like can also be added.

The aqueous ink composition of the present invention thus obtained is
It has the following characteristics.

First, it has excellent water resistance because it is based on a water-insoluble colored polymer. Therefore, the drawbacks of conventional water-based inks, such as ink smearing due to water, sweat, etc., and printed areas disappearing, are eliminated.

Second, the disadvantages of salt dyes, which were thought to have low light resistance and solubility, have been overcome by dyeing water-soluble polymers with basic dyes.

In other words, it is possible to provide a water-based ink that has the characteristics of basic dyes, such as the richness of colors, the sharpness of one color, and the appearance of a deep color per weight unit, and also has excellent light resistance and solubility. be.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited in any way by these Examples. Note that parts and percentages in the examples are based on weight unless otherwise specified.

Water-soluble polymer synthesis example-1 40 parts of water was charged into a polymerization flask purged with nitrogen, and the temperature was raised to 90°C. 56 parts of Subinomer Na5s (sodium p-styrene sulfonate, purity 81.0%, manufactured by Toyo Soda Kogyo), 116 parts of 2-hydroxyethyl methacrylate, and 4 parts of water.
A monomer aqueous solution was prepared by dissolving 88 parts of the monomer.

A polymerization initiator aqueous solution was prepared by dissolving 3 parts of ammonium persulfate in 97 parts of water.

A monomer aqueous solution and a polymerization initiator aqueous solution were added over 6 hours and polymerized at 90°C. The mixture was further polymerized at 90°C for 2 hours and cooled. Solution viscosity at 25°C was 52 ops.

When the amount of unreacted monomer was determined by the bromine addition method, the polymerization rate of the monomer was 99.1%.

Furthermore, the average molecular weight of the polymer was determined by gel permidine chromatography and was found to be MY5X10'.

The polymer was purified, and the sulfur analysis value showed that the polymer contained 1.70 Xl 0 = Durham equivalent/g polymer sulfonic acid group, which was the same as the calculated value from the amount of monomer charged. Similarly, the content of hydroxyl groups is 5.6 X 10-'' gram equivalents/gram polymer.

Water-soluble polymer synthesis example-2 50 parts of water was charged into a polymerization flask purged with nitrogen, and the temperature was raised to 90°C. Spinomer Na5S (sodium P-styrene sulfonate, purity 81.9%, manufactured by Toyo Soda Kogyo) 73 parts, 122 parts of 2-hydroxyethyl methacrylate, 2-
A monomer aqueous solution was prepared by dissolving 122 parts of hydroxyethyl acrylate in 603 parts of water.

A polymerization initiator aqueous solution was prepared by dissolving 24 parts of ammonium persulfate in 56 parts of water.

A monomer aqueous solution and a polymerization initiator aqueous solution were added over 3 hours and polymerized at 90°C. The mixture was further polymerized at 90°G for 2 hours and cooled. The solution viscosity at 25°C was 255 Qp8.

The polymerization rate of monomer was 99.5% in the same manner as Synthesis Example-1.
and the average molecular weight was MwIXIG'.

Also, the sulfonic acid group in the polymer is 9 x 10 → gram equivalent/gram polymer, and the hydroxyl group is 6.1SX10
= gram equivalent/gram polymer.

Water-soluble polymer synthesis example-3 50 parts of water was charged into a polymerization flask purged with nitrogen, and the temperature was raised to 90°C. Subi/Mar N&5S (sodium P-styrene sulfonate purity 81.9% manufactured by Toyo Soda Kogyo) 117
106 parts of 2-hydroxyethyl methacrylate and 40 parts of acrylamide were dissolved in 657 parts of water to prepare an aqueous monomer solution.

A polymerization initiator aqueous solution was prepared by dissolving 19 parts of ammonium persulfate in 61 parts of water.

A monomer aqueous solution and a polymerization initiator aqueous solution were added over 3 hours and polymerized at 90°C. The mixture was further polymerized at 90° C. for 2 hours and cooled. The solution viscosity at 25°C was 65 ops.

The polymerization rate of monomer was 99.3% in the same manner as Synthesis Example-1.
and the average molecular weight was Mav = I x 10'. In addition, the sulfonic acid group in the polymer is 1.9x 1o
-s gram equivalent/gram polymer, hydroxyl groups are N
4×10-” gram equivalents/gram polymer.

Examples-1 to 3 Water-soluble polymer 2 obtained in Water-soluble polymer synthesis example-1
5 parts and 3 parts of basic dye (manufactured by Hodogaya Chemical).

1 part of acetic acid dissolved in 51 parts of water was added, stirred at 60°C for 1 hour to produce a colored polymer, and 20 parts of r-butyrolactone was added to prepare a water-based ink.

m Dye used Ink cough (cps) Examples 1-3
Using a felt-tip pen filled with each of the water-based inks obtained in , I wrote on J-Ko S P 5201 writing paper A. After 1 minute, I immersed the writing paper in water for 1 hour and observed the state of the handwriting, but the handwriting did not smudge. , there was almost no dirt and the density did not change. Furthermore, each water-based ink was applied to the above writing paper using a 1 mil doctor blade, and measured using a kimonoso fade meter (black spring A/temperature 65°C ± 6°C relative humidity 3).
5±5%), and tested for sunlight fastness.
When compared with the degree of discoloration of -0841 Blue Scale, the sunlight fastness of each dye itself was about Blue Scale Grade 1, but all of the water-based inks mentioned above were Blue Scale Grade 1/I/6 to 4. Ta.

Examples 4 to 6 9 parts of the water-soluble polymer obtained in Synthesis Example 2, 10 parts of reamer, and 2 parts of a basic dye (Nippon Kaso).

1 part acetic acid, 20 parts N-methyl-2-pyrrolidone.

67 parts of water was added and stirred at 60° C. for 1 hour to prepare a colored polymer, and 10 parts of ethylene glycol and 5 parts of methyl P-hydroxybenzoate α were added to prepare an aqueous ink.

Cheeks - dye ink used (DfJJl (op s
) Each water-based ink obtained in Examples 4 to 6 was used in Example 1.
A water resistance test was conducted in the same manner as in 3. The handwriting did not smudge or stain, and the density did not change.

Furthermore, the sunlight oxidation degree of each water-based ink was about 4th grade.

Examples-7 to 9 Water-soluble polymer 2 obtained in Water-soluble polymer synthesis example-3
0 parts and 6 parts of basic dye (manufactured by Hodogaya Chemical).

1 part acetic acid, 20 parts NN'-dimethylformamide.

53 parts of water was added and stirred at 60° C. for 1 hour to produce a colored polymer, and 15 parts of diethylene glycol was added to prepare a water-based ink.

Tokusaba Dye used Ink quality (cps) (0, engineering,
Basic Red 38) When the water-based inks obtained in Examples 7 to 9 were subjected to a water resistance test in the same manner as in Examples 1 to 3, the handwriting did not smudge or stain, and the density did not change. In addition, the sunlight fastness of each aqueous ink was about grade 4.

Examples-10 to 12 Water-soluble polymer 5 obtained in Water-soluble polymer synthesis example-2
To 0 parts, 10 parts of basic dye (manufactured by Hodogaya Chemical Co., Ltd.) and 40 parts of water were added, and the mixture was stirred at 60°C for 1 hour to produce a colored polymer.
30 parts of γ-butyrolactone was added to this to prepare an aqueous ink.

m Dye used IMI of ink (c p s)
10 Kachiron Yellow 3GLH1! L1 (0, hard, basic yellow 11) The water resistance 9 sunlight fastness of each of the aqueous inks obtained in Examples 10 to 12 was comparable to that of Examples 1 to 6. Also,
While each of the above water-based inks is a uniform aqueous solution,
When no water-soluble polymer was used and the other conditions were the same, the aqueous ink containing each dye itself contained a large amount of insoluble matter of the basic dye, and did not become a uniform aqueous solution.

Patent applicant: Toyo Soda Kogyo Co., Ltd. Procedural amendment May 16, 1980.

Kazuo Wakasugi, Commissioner of the Japan Patent Office 1 Display of the case 1982 Patent Application No. 56281 2 Name of the invention Aqueous ink composition 6 Person making the amendment Telephone number (585)! +311 4. Date of amendment order A. 6. Specification to be amended 7. Contents of amendment; engraving of the specification (no change in content) Procedural amendment June 15, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi Indication of case 1 Patent Application No. 56281 of 1988 2 Name of the invention Aqueous ink composition 6 Person making the amendment Telephone number (585) 3311 6 Subject of amendment (1) Patent specification of written amendment dated May 16, 1988 Scope of Claims Column (2) Detailed Description of the Invention in the Specification Column 7 Contents of Amendment (1) Correct as per 11ll”%F!νm.

(2) "Weather resistance" in line 4 of page 3 is corrected to "light resistance."

(3) From page 3, line 15 to page 4, line 1, “that is, to provide...” was replaced with “that is, to provide...”
The present invention provides hydroxyl groups greater than or equal to I
A water-based ink composition consisting of a mixed solvent solution of water and a water-soluble organic solvent of a colored polymer in which a water-soluble polymer containing sulfonic acid groups greater than or equal to gram polymer has been dyed with a basic dye to become water-insoluble. This is a summary. ” he corrected.

(4) It is presumed that -[ on page 4, line 18 of the same page is possible. ", then add "However, a water-insoluble polymer dyed with a basic dye cannot be dissolved in water using a small amount of a water-soluble organic solvent."

(5) On page 10, line 5, "of the present invention" is corrected to "in this specification."

(6) On page 10, line 6, "means." is corrected to "means in a broad sense."

(7) Page 13, line 3 (“ga dekiru”) and line 11
Between the line (“Represented by general formula (1)...”) ([
General formula... Tsukasa) [General formula [I] General formula [■]; Y represents OH or 0. )” is corrected.

(8) Delete "dimethyl sulfoxide" from the 6th line from the bottom of page 13.

(9) On page 15, line 14, ``C means shi unless otherwise specified.'' is corrected to ``C related to composition.''

Attachment [2 Claims (1) IXlo-8 gram equivalent/gram polymer An aqueous ink composition comprising a hydroxyl group of 3° or more and a sulfone solvent solution of 1×10 → gram equivalent/gram polymer or more.

(2) The water-soluble organic solvent has the following general formula [1] or (n
) The aqueous ink composition according to claim 1, which is represented by:

General formula (1) General formula [1]

Claims (1)

[Scope of Claims] (1) A water-soluble polymer containing one or more hydroxyl groups in the polymer and one or more hydroxyl groups in the polymer and one or more sulfonic acid groups in the polymer in an amount of I An aqueous ink composition comprising a water-insoluble colored Borimani dyed with a water-soluble organic solvent. (2) The water-soluble organic solvent has the following general formula [1] or (1)
) The aqueous ink composition according to claim 1. General formula (1) R1114X1 (R1-1 horse is H or C bird, horse is N0
Represents 0°00HB or SO. )