JPH11217525A - Water-based ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water born ink that causes reduced ink bleeding, and excellent is water resistance and ink fixation and is particularly useful as an ink for ink jet recording. SOLUTION: This water born ink includes (1) a polymer emulsion that is prepared by sulfonating a polymer or copolymer or a hydrogenated product thereof containing a diene compound as a structure unit and (2) at least one selected from dyes or pigments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink which has a small amount of ink bleeding and is excellent in water resistance and fixability of printed matter, and more particularly to a water-based ink useful as an ink for ink-jet recording.

[0002]

2. Description of the Related Art A method of recording on a base material such as paper by an ink jet method has been adopted in printers such as computers and has been rapidly spreading in recent years. The recording method using the ink-jet method is a method of recording images and characters by flying small droplets of ink and attaching them to a recording sheet such as paper or a polymer sheet. Possible, and the recording pattern has great flexibility,
It has features such as no need for fixing. Further, it is possible to obtain an image formed by the multi-color ink jet recording method, which is comparable to multi-color printing by a plate making method or printing by a color photographic method. A water-soluble dye that is usually dissolved in water is used for ink used in an ink-jet printer, which is one of typical printer devices, in order to prevent nozzles from being clogged with ink. The use of the water-soluble dye makes it difficult for the ink to clog the nozzles, but has a problem in the water resistance of the printed matter. Therefore, in order to improve the water resistance of the printed matter, the composition of the ink is important. Conventionally, in order to improve water resistance, a pigment is used instead of a water-soluble dye (JP-A-4-28776), a non-aqueous medium is used (JP-A-4-26147), or a dye having excellent water resistance is used. (US Pat. No. 4,963,189) has been proposed. However, when a pigment is used as the ink, there has been a problem that the fixation of the ink to paper, an OHP sheet, or the like is insufficient, and the recording storability is poor. The use of the non-aqueous solvent improves the water resistance to some extent, but causes a problem of environmental pollution. Other suggestions,
There is still a problem in that the prevention of bleeding of the ink, the water resistance of the printed matter, the fixability, and the printing properties are still insufficient, and there has been a demand for a more excellent aqueous ink.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water-based ink which is free from ink bleeding, has excellent water resistance and excellent fixability of printed matter, and has excellent printing characteristics.
It is an object to provide a water-based ink for inkjet.

[0004]

The present invention provides 1) an emulsion of a polymer obtained by sulfonating a polymer or copolymer containing a diene compound as a constituent unit or a hydrogenated product thereof, and 2). An object of the present invention is to provide an aqueous ink containing at least one selected from dyes and pigments.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The diene (co) polymer used in the present invention or a sulfonated product of a hydrogenated product thereof (hereinafter also referred to as "hydrogenated product") is a diene (co) polymer (hereinafter, referred to as "hydrogenated product") having a diene monomer as an essential component. Or a hydrogenated product thereof). The diene monomer used for the base polymer is preferably a diene compound having 4 to 10 carbon atoms, more preferably a diene compound having 4 to 8 carbon atoms, and still more preferably a diene compound having 4 to 6 carbon atoms.

As specific examples of the diene monomer, for example, 1,3-butadiene, 1,2-butadiene, 1,2
-Pentadiene, 1,3-pentadiene, 2,3-pentadiene, isoprene, 1,2-hexadiene, 1,3
-Hexadiene, 1,4-hexadiene, 1,5-hexadiene, 2,3-hexadiene, 2,4-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, , 2-heptadiene, 1,
3-heptadiene, 1,4-heptadiene, 1,5-heptadiene, 1,6-heptadiene, 2,3-heptadiene, 2,5-heptadiene, 3,4-heptadiene,
In addition to 3,5-heptadiene, cyclopentadiene, dicyclopentadiene, ethylidene norbornene, etc., various branched aliphatic or alicyclic dienes having 4 to 7 carbon atoms may be mentioned. One type may be used alone, or two or more types may be used in combination. Can be used. Particularly preferred are 1,3-butadiene and isoprene.

In addition to these diene monomers, other monomers can be used in combination. As other monomers,
For example, aromatic monomers such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acryl Alkyl (meth) acrylates such as butyl acid, mono- or dicarboxylic acids or anhydrides of dicarboxylic acids or dicarboxylic acids such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid, and vinyl cyanides such as (meth) acrylonitrile Compound, vinyl chloride, vinylidene chloride, vinyl methyl ethyl ketone, vinyl acetate, (meth)
Unsaturated compounds such as acrylamide and glycidyl (meth) acrylate; These other monomers are 1
These can be used alone or in combination of two or more.
Of these other monomers, styrene is preferred.
When these other monomers are used in combination, the amount of the diene monomer used is preferably 0.5% by weight or more, more preferably 1% by weight or more, and particularly preferably 5% by weight or more. If it is less than 0.5% by weight, the content of sulfonic acid (salt) group introduced into the sulfonated product obtained by sulfonation may be low, which is not preferable.

The base polymer comprises a diene monomer and, if necessary, other monomers, a radical polymerization initiator such as hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, n-butyllithium, sodium naphthalene, metal In the presence of an anionic polymerization initiator such as sodium, using a known solvent if necessary,
Usually, -100 to 150 ° C, preferably 0 to 130 ° C
To obtain (co) polymerization.

Further, as the base polymer, part or all of the remaining double bonds based on the diene monomer of the base polymer which is a precursor of the sulfonated diene (co) polymer can be used after hydrogenation. . In this case, a known hydrogenation catalyst can be used.
No. 115, a catalyst and a method as described therein. After hydrogenation of the base polymer, sulfonation can be performed by the method described below, but the (co) polymer may be sulfonated and then hydrogenated.

[0010] The base polymer used in the present invention may be any of a random type or a block type copolymer such as AB type or ABA type without any particular limitation. Preferred base polymers include, for example, isoprene homopolymer,
Butadiene homopolymer, isoprene-styrene random copolymer, isoprene-styrene block copolymer, styrene-isoprene-styrene ternary block copolymer,
Butadiene-styrene random copolymer, butadiene-
Styrene block copolymer, styrene-butadiene-styrene block copolymer, butadiene-styrene-butadiene ternary block copolymer and hydrogenated products of these (co) polymers, ethylene-propylene-diene terpolymer Is mentioned. Of these, more preferred are isoprene-styrene block copolymer, styrene-isoprene-styrene ternary block copolymer, butadiene-styrene block copolymer, styrene-butadiene-styrene block copolymer, butadiene styrene. A block copolymer having an aromatic polymer unit such as hydrogenated butadiene ternary block copolymer, a hydrogenated product thereof and a conjugated diene polymer unit; and a hydrogenated product thereof.

The polystyrene-equivalent weight average molecular weight (hereinafter referred to as “Mw”) of the base polymer containing a diene monomer as an essential component or a hydrogenated product thereof is preferably 1,0.
00 to 1,000,000, more preferably 3,000.
0 to 500,000, particularly preferably 5,000 to 40
It is 0000. If the Mw is less than 1,000, the function of the ink as a binder is reduced, which may cause problems in water resistance and fixability.
If it exceeds 0, problems such as gelation during sulfonation may occur.

The sulfonated diene (co) polymer of the present invention can be prepared by subjecting the above base polymer to a known method, for example, edited by the Japan Society of Science, New Experimental Course (Vol. 14, III, pp. 1773) or JP-A-2-227403. And obtained by sulfonation according to the method described in Japanese Patent Application Laid-Open Publication No. H10-15095. That is, the base polymer can be sulfonated by using a sulfonating agent at a double bond portion of a diene unit in the polymer. In this sulfonation, the double bond is opened to form a single bond, or a hydrogen atom is replaced with a sulfonic acid (salt) while the double bond remains. When another monomer is used, an aromatic unit may be sulfonated in addition to a diene unit portion in a double bond portion. The sulfonating agent in this case is preferably sulfuric anhydride, a complex of sulfuric anhydride and an electron donating compound, sulfuric acid, chlorosulfonic acid, fuming sulfuric acid, bisulfite (Na salt, K salt, Li salt, etc.). Are used.

Here, as the electron donating compound, N,
Ethers such as N-dimethylformamide, dioxane, dibutyl ether, tetrahydrofuran, diethyl ether; pyridine, piperazine, trimethylamine,
Amines such as triethylamine and tributylamine;
Sulfides such as dimethyl sulfide and diethyl sulfide; nitrile compounds such as acetonitrile, ethyl nitrile and propyl nitrile; and the like, of which N, N-dimethylformamide and dioxane are preferable.

The amount of the sulfonating agent is usually from 0.005 to 1.5 mol in terms of sulfuric anhydride, relative to the total of 1 mol of the diene unit and the aromatic unit in the base polymer.
It is preferably 0.01 to 1.0 mol, and if it is less than 0.005 mol, the desired sulfonation ratio cannot be obtained, so that various performances cannot be exhibited, and on the other hand, more than 1.5 mol Then, the amount of unreacted sulfuric anhydride increases, and after neutralization with an alkali, a large amount of sulfate is generated to lower the purity.

In the sulfonation, a solvent inert to a sulfonating agent such as sulfuric anhydride may be used. Examples of the solvent include chloroform, dichloroethane, and the like.
Halogenated hydrocarbons such as tetrachloroethane, tetrachloroethylene and dichloromethane; nitro compounds such as nitromethane and nitrobenzene; aliphatic hydrocarbons such as liquid sulfur dioxide, propane, butane, pentane, hexane, and cyclohexane; and ether solvents such as dioxane and tetrahydrofuran. No. These solvents may be used as a mixture of two or more. The reaction temperature of this sulfonation is usually -70 to 200 ° C,
The temperature is preferably -30 to 50 ° C, and if the temperature is lower than -70 ° C, the sulfonation reaction is slow, which is not economical. On the other hand, if the temperature exceeds 200 ° C, a side reaction occurs, and the product may be blackened or insolubilized.

The sulfonated diene (co) polymer of the present invention can be obtained by reacting the product with water or a basic compound. Examples of the basic compound include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide; sodium methoxide, sodium ethoxide, potassium methoxide, sodium methoxide.
alkali metal alkoxides such as t-butoxide and potassium-t-butoxide; carbonates such as sodium carbonate, potassium carbonate and lithium carbonate; methyl lithium, ethyl lithium, n-butyl lithium, sec-butyl lithium, amyl lithium, propyl sodium, Organometallic compounds such as methylmagnesium chloride, ethylmagnesium bromide, propylmagnesium iodide, diethylmagnesium, diethylzinc, triethylaluminum, triisobutylaluminum; ammonia water, trimethylamine, triethylamine, tripropylamine, tributylamine, pyridine, aniline, dimethyl Amines such as ethanolamine and piperazine; sodium, lithium, potassium, calcium,
Metal compounds such as zinc can be mentioned. These basic compounds can be used alone or in combination of two or more. Among these basic compounds, alkali metal hydroxides and aqueous ammonia are preferable, and sodium hydroxide and lithium hydroxide are particularly preferable.

The amount of the basic compound used is 2 mol or less, preferably 1.3 mol, per mol of the sulfonating agent used.
Mol or less. In this reaction, the basic compound can be used in the form of an aqueous solution, or can be used by dissolving it in an organic solvent inert to the basic compound. Examples of the organic solvent include various organic solvents used for the sulfonation, aromatic hydrocarbon compounds such as benzene, toluene, and xylene; and alcohols such as methanol, ethanol, propanol, isopropanol, and ethylene glycol. Can be These solvents may be used as a mixture of two or more.

When the basic compound is used as an aqueous solution or an organic solvent solution, the basic compound concentration is usually
It is about 1 to 70% by weight, preferably about 10 to 50% by weight. The reaction temperature is usually -30 to 150 ° C,
Preferably it is 0-120 degreeC, More preferably, it is 50-10.
It is carried out at 0 ° C. and can be carried out at normal pressure, reduced pressure or increased pressure. Further, the reaction time is generally 0.1 to 24 hours, preferably 0.5 to 5 hours.

The sulfonic acid (salt) group content of the above-mentioned sulfonated diene (co) polymer is usually from 0.1 to 0.1.
3.5 mmol / g, preferably 0.2-3 mmol / g
g. If it is less than 0.1 mmol / g, as described later, the particle size of the emulsion in water becomes large, which is not preferable. On the other hand, if it exceeds 3.5 mmol / g, the water resistance decreases, which is not preferable. Such diene-based (co) compounds of the present invention
The structure of the polymer sulfonate can be confirmed from the absorption of the sulfone group by an infrared absorption spectrum, and the composition ratio thereof can be known by elemental analysis or the like. The structure can be confirmed by a nuclear magnetic resonance spectrum.

The diene compound (co) thus synthesized
The sulfonated polymer is prepared by emulsifying in water (hereinafter, referred to as
The emulsification process is also called "re-emulsification"). The method of re-emulsification is to stir and mix an organic solvent solution of the sulfonated product or the product before neutralization with water or the alkali compound, emulsify, and then remove the organic solvent while leaving water. Is obtained by For this re-emulsification, a general method can be adopted, a method in which water is added to the organic solvent solution of the sulfonated product while stirring, a method in which an organic solvent solution of the sulfonated product is added to water while stirring, water and sulfone. There is no particular limitation on a method of simultaneously adding a solution of the compound in an organic solvent and stirring the solution.

The organic solvent used for the re-emulsification includes, for example, aromatic solvents such as toluene and xylene;
Aliphatic solvents such as hexane and heptane; ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxane; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as methanol, ethanol and isopropyl alcohol; Is used. These solvents can be used alone or
It may be used in combination of more than one kind.

The amount of the organic solvent used in the re-emulsification is preferably 20 to 5,000 parts by weight, more preferably 50 to 50 parts by weight, per 100 parts by weight of the sulfonated product.
2,000 parts by weight. When the amount is less than 20 parts by weight, a stable re-emulsified product cannot be obtained. On the other hand, when the amount exceeds 5,000 parts by weight, productivity deteriorates. The amount of water used in the re-emulsification is preferably 50 to 10,000 parts by weight, more preferably 100 to 5,000 parts by weight, based on 100 parts by weight of the sulfonate. If the amount is less than 50 parts by weight, a stable re-emulsified product cannot be obtained. If the amount exceeds 10,000 parts by weight, productivity is deteriorated.

In the re-emulsification, a surfactant may be used in combination. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ether, polyoxysorbitan ester, and polyoxyethylene alkylamine ether, oleate, laurate, rosinate, dodecylbenzene sulfonate. And anionic surfactants such as polyoxyethylene alkyl ether sulfate, and cationic surfactants such as octyltrimethylammonium bromide, dioctyldimethylammonium chloride and dodecylpyridinium chloride. These surfactants can be used alone or in combination of two or more. The surfactant may be used by dissolving or dispersing it in an organic solvent solution of a sulfonate, or may be used by dissolving or dispersing it in water. The amount of the surfactant used is a diene (co)
It is usually at most 10 parts by weight, preferably at most 5 parts by weight, based on 100 parts by weight of the polymer sulfonate. If the amount exceeds 15 parts by weight, the purity of the sulfonated emulsion (re-emulsified product) is reduced.

In order to adjust the pH in the system, an alkali compound such as sodium hydroxide and lithium hydroxide;
Inorganic acids such as hydrochloric acid and sulfuric acid can also be added. If the amount is small, an organic solvent other than water can be used in combination. The aqueous ink of the present invention can be obtained by mixing the above-mentioned diene-based (co) polymer sulfonated product emulsion with a dye or pigment described later.

A more preferable method in terms of ink performance is a method in which the sulfonated polymer is re-emulsified in the presence of a dye or a pigment. That is, a method of dissolving or dispersing the neutralized sulfonated polymer and dye or pigment in an organic solvent, followed by re-emulsification with stirring in water,
Alternatively, a method in which a dye or a pigment is dissolved in an organic solvent solution of the sulfonated polymer before the neutralization, and a method of re-emulsifying in water containing a basic compound, and the like, can be used, and can be adjusted by various emulsification methods as needed. . In these cases, the above-mentioned emulsifiers, basic compounds, organic solvents and the like can be used in the same manner. By emulsifying the sulfonated polymer in the presence of the dye or pigment, the dye or pigment is easily incorporated into the sulfonated polymer micelles, or is easily adsorbed to the sulfonated polymer. A water-based ink having excellent fixability and printing characteristics can be obtained.

The particle size of the re-emulsified emulsion of the sulfonated product thus obtained (including the emulsion containing a dye or pigment) is usually from 1 to 500 n.
m, preferably 2 to 100 nm. In the aqueous ink of the present invention, the emulsion of the sulfonated polymer,
The content is usually 1 to 50% by weight, preferably 2 to 30% by weight in terms of solid content in the ink. If it is less than 1%, the print quality is reduced, and if it exceeds 50%, the storage stability as an ink may be reduced.

The dye used in the present invention can be used without any particular limitation. For example, aqueous dyes, oily dyes, disperse dyes, direct dyes, acid dyes, basic dyes and the like can be mentioned, and preferably oily dyes or disperse dyes. Examples of the disperse dye include C.I. I. Disperse Yellow 5, 42, 54, 64, 79, 82, 83,
93, 100, 122, 124, 126, 160, 18
4,199,204 and 224, C.I. I. Disperse Orange 13, 29, 31, 33, 49, 54, 5
5, 66, 73, 118 and 163, C.I. I. Disperse Red 60, 72, 73, 86, 88, 91, 9
2,93,111,126,127,134,135
145, 164, 177, 181, 204, 206, 2
07, 239, 240, 283, 323, 343, and 362, C.I. I. Disperse Blue 56, 60, 7
3,87,113,128,143,148,154,
158, 197, 198, 201, 257, 266, 2
87, 354 and 365, and C.I. I. Disperse Green 9 and the like.

Examples of the oily dyes include C.I. I.
Solvent Black 3, 7, 27, 29, and 3
4, C.I. I. Solvent Yellow 14, 16, 19,
29, 56, 82 and 162, C.I. I. Solvent
Red 1, 3, 8, 18, 24, 27, 43, 51 and 72, C.I. I. Solvent Blue 2, 11, 70 and the like. Examples of the direct dye include C.I.
I. Direct Black 19 and the like. Examples of the acid dye include C.I. I. Acid Black 2 and 12, C.I. I. Acid Yellow 23, C.I.
I. Acid Red 51, 87 and 92, C.I. I. Acid Blue 1, 9 and 74. Examples of the basic dye include C.I. I. Basic Yellow 2 and 11, C.I. I. Basic Red 1 and 13, C.I. I. Basic Blue 5, 7, 9 and 26, and the like. The above dyes can be used alone or in combination for 2 weeks or more.

On the other hand, examples of the pigment used in the water-based ink of the present invention include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, and dioxazines. Pigments, thioindigo pigments, isoindolinone pigments, polycyclic pigments such as quinophthaloni pigments, dye lakes, nitro pigments, nitroso pigments, aniline black, fluorescent pigments and other organic pigments, titanium oxide, iron oxide, carbon black, etc. No. The above pigments can be used alone or in combination of two or more. The above dyes and pigments can be used alone or in combination of two types without any problem. The concentration of the dye or pigment incorporated in the aqueous ink of the present invention is usually 1% to 30%, preferably 1.5% to 25%. If the concentration of the dye or pigment is less than 1%, the printing density is not sufficient, and if it exceeds 30%, the particle size of the dispersion may increase or aggregation may occur.

In addition to the above-mentioned sulfonated polymer emulsion, dye, pigment and water, known additives can be added to the aqueous ink of the present invention. For example, wetting agents such as polyhydric alcohols, dispersants, defoamers, surface tension regulators such as various surfactants, chelating agents, oxygen absorbers, and the like can be added.
Examples of the wetting agent include glycols such as ethylene glycol, propylene glycol, and diethylene glycol; polyhydric alcohol ethers such as glycerin, diethylene glycol monobutyl ether and carbitol; acetates; thiodiglycol; and N-methyl-2.
-Nitrogen-containing compounds such as pyrrolidone and triethanolamine. Examples of the dispersant include anionic surfactants such as fatty acid salts and alkyl sulfonates, cationic surfactants such as aliphatic amines and quaternary ammonium salts, amphoteric surfactants such as betaine-type compounds, and polyoxygens. Nonionic surfactants such as fatty acid ester types of ethylene compounds, cellulose-based polymers,
Lignin sulfonic acid salt, polyacrylic acid salt, styrene-acrylic acid copolymer salt, styrene-maleic acid copolymer salt, formalin condensate of naphthalene sulfonic acid, polyvinyl alcohol, polyethylene glycol and the like.

The aqueous ink of the present invention preferably satisfies specific physical properties. For example, inks used for ink-jet recording must have proper viscosity and surface tension. The viscosity of the inkjet recording ink of the present invention at 25 ° C. is usually 0.7 cp to 15 cp, preferably 1 cp to 10 cp. The surface tension is
20 dynes / cm to 70 dynes / cm at 25 ° C,
Preferably 25 dynes / cm to 60 dynes / cm, more preferably 30 dynes / cm to 40 dynes / cm
It is.

The water-based ink of the present invention is particularly useful for ink-jet recording, but can also be used as other inks, for example, as ink for writing implements such as general fountain pens, ball-point pens, and felt-tip pens.

[0033]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% are by weight unless otherwise specified. Reference example (synthesis of sulfonated product or emulsion containing dye, preparation of pigment);

Reference Example 1 100 g of dioxane was placed in a glass reaction vessel, and 11.8 g of sulfuric anhydride was added thereto while maintaining the internal temperature at 25 ° C., followed by stirring for 2 hours to obtain a sulfuric anhydride-dioxane complex. Styrene / isoprene / styrene ternary block copolymer (10/80/10 weight ratio, Mw = 100000)
The total amount of the complex obtained above was added to 100 g of a THF solution (concentration = 15%) while maintaining the internal temperature at 25 ° C.,
Stirring was continued for another 2 hours. 1200 g of water, 7.1 g of sodium hydroxide, and 1 g of sodium dodecylbenzenesulfonate were placed in a flask, and the internal temperature was maintained at 40 ° C. Into this, the entire amount of the solution was added dropwise over 1 hour while maintaining the internal temperature at 40 ° C. After dropping, 40 ° C
After stirring for 2 hours, the solvent was removed by distillation under reduced pressure while leaving water to obtain a sulfonated polymer emulsion having a concentration of 15%. The particle size of the emulsion was 30 nm, and the sulfonic acid content in the solid content was 1.2 mmol / g.

Reference Example 2 100 g of 1,2-dichloroethane was placed in a glass reaction vessel.
Was added thereto, and 11.8 g of sulfuric anhydride was added thereto while keeping the internal temperature at 25 ° C., to obtain a 1,2-dichloroethane solution of sulfuric anhydride. Butadiene / styrene / butadiene copolymer (30
/ 40/30, weight ratio, Mw = 50000) of hydrogenated diene units (hydrogenation ratio 99%), 100 g of 1,2
-The entire amount of the anhydrous sulfuric acid solution obtained above was added to a dichloroethane solution (concentration = 15%) over 1 hour while maintaining the internal temperature at 25 ° C, and stirring was continued for 2 hours.
After stirring, about 1,500 g of 1,2-dichloroethane was removed under reduced pressure, and then 500 g of THF was added. 1200 g of water, 7.1 g of sodium hydroxide, and 1 g of sodium dodecylbenzenesulfonate were placed in a flask, and the internal temperature was maintained at 40 ° C. Into this, the entire amount of the solution was added dropwise over 1 hour while maintaining the internal temperature at 40 ° C. After dropping, 40 ° C
After stirring for 2 hours, the solvent was removed by distillation under reduced pressure while leaving water to obtain a sulfonated polymer emulsion having a concentration of 15%. The particle size of the emulsion was 40 nm, and the sulfonic acid content in the solid content was 1.0 mmol / g.

Reference Example 3 200 g of dioxane was placed in a glass reaction vessel, and 23.6 g of sulfuric anhydride was added thereto while maintaining the internal temperature at 25 ° C., followed by stirring for 2 hours to obtain a sulfuric anhydride-dioxane complex. Styrene / isoprene / styrene ternary block copolymer (10/80/10 weight ratio, Mw = 100000)
The total amount of the complex obtained above was added to 100 g of a THF solution (concentration = 15%) while maintaining the internal temperature at 25 ° C.,
Stirring was continued for another 2 hours. OI which is oily dye
L YELLOW 107 (Orient Chemical Industry Co., Ltd.)
Was added and dissolved. 1200 g of water, 7.1 g of sodium hydroxide, and 1 g of sodium dodecylbenzenesulfonate were placed in a flask, and the internal temperature was maintained at 40 ° C. In this, the total amount of the solution is
Dropwise over 1 hour while maintaining the internal temperature. After the dropwise addition, the mixture was stirred at 40 ° C. for 2 hours, and then the solvent was removed by distillation under reduced pressure while leaving water to obtain an emulsion of a 15% concentration sulfonated polymer and dye. The particle size of the emulsion was 40 nm, and the sulfonic acid content in the solid content was 1.8 mmol / g.

Reference Example 4 100 g of 1,2-dichloroethane was placed in a glass reaction vessel.
Was added thereto, and 23.1 g of sulfuric anhydride was added thereto while maintaining the internal temperature at 25 ° C., to obtain a 1,2-dichloroethane solution of sulfuric anhydride. Butadiene / styrene / butadiene copolymer (30
/ 40/30, weight ratio, Mw = 50000) of hydrogenated diene units (hydrogenation ratio 99%), 100 g of 1,2
-The entire amount of the anhydrous sulfuric acid solution obtained above was added to a dichloroethane solution (concentration = 15%) over 1 hour while maintaining the internal temperature at 25 ° C, and stirring was continued for 2 hours.
After stirring, about 1,500 g of 1,2-dichloroethane was removed under reduced pressure, and 500 g of THF and O, an oil dye, were removed.
IL BLACK HBB (Orient Chemical Industry Co., Ltd.)
Was added and dissolved. 1200 g of water, 7.1 g of sodium hydroxide, and 1 g of sodium dodecylbenzenesulfonate were placed in a flask, and the internal temperature was maintained at 40 ° C. Into this, the entire amount of the solution was added dropwise over 1 hour while maintaining the internal temperature at 40 ° C. After dropping, 40 ° C
After stirring for 2 hours at, the solvent was removed by distillation under reduced pressure while leaving water to obtain a sulfonated polymer and a dye emulsion having a concentration of 15%. The particle size of the emulsion was 40 nm, and the sulfonic acid content in the solid content was 1.8 mmol / g.

Reference Example 5 Carbon black (MA-100 manufactured by Mitsubishi Chemical Corporation)
20 g, styrene-maleic anhydride copolymer (oxidation; 1
30, molecular weight 9000) 2 g, diethanolamine 3
g, 25 g of diethylene glycol and 45 g of water were subjected to a dispersion treatment for 2 hours by a paint conditioner using zirconia balls as grinding media. After the treatment, dust and coarse particles were removed by centrifugation.

Example 1 88 g of the emulsion obtained in Reference Example 1, 7.5 g of diethylene glycol, 1 g of glycerin, WATER RED3
3.5 g (manufactured by Orient Chemical Industries, Ltd.) were mixed.
The obtained dispersion was filtered through a 5-micron filter to obtain an inkjet ink. The viscosity of the ink is 3.2c
ps. Example 2 The procedure of Example 1 was repeated, except that the emulsion obtained in Reference Example 2 was used instead of the emulsion obtained in Reference Example 1. The viscosity of the ink was 2.6 cps. Example 3 91 g of an emulsion containing the dye obtained in Reference Example 3, 8.0 g of diethylene glycol, and 1 g of glycerin were mixed. The obtained dispersion was filtered through a 5-micron filter to obtain an inkjet ink. The viscosity of the ink is 3.
It was 0 cps.

Example 4 The procedure of Example 3 was repeated, except that the emulsion obtained in Reference Example 4 was used instead of the emulsion obtained in Reference Example 3. The viscosity of the ink was 3.1 cps. Example 5 17 g of the pigment dispersion obtained in Reference Example 5, 75 g of the emulsion obtained in Reference Example 1, 7.0 g of diethylene glycol,
1 g of glycerin was mixed. The obtained dispersion was filtered through a 5-micron filter to obtain an inkjet ink. The viscosity of the ink was 3.5 cps. Example 6 Example 5 was carried out in the same manner as in Example 5, except that the same amount of the emulsion obtained in Reference Example 2 was used instead of the emulsion obtained in Reference Example 1. The viscosity of the ink was 3.5 cps.

Comparative Example 1 Water-soluble dye WATER YELLOW 1 (manufactured by Orient Chemical Industry Co., Ltd.) 3.5 g, ethanolamine 2 g, diethylene glycol 10 g, glycerin 3 g,
81.5 g of ion-exchanged water was mixed. The obtained dispersion was filtered through a 5-micron filter to obtain an inkjet ink. The viscosity of the ink was 2.5 cps.

(Evaluation method) The obtained ink was treated with MJ830.
Printing was performed using C (manufactured by Seiko Epson Corporation), and various characteristics were evaluated according to the following criteria. 1. Bleeding After printing on recycled paper, it was left for 1 hour. Thereafter, the degree of bleeding of the letters was observed with a microscope and visually, and evaluated according to the following criteria. ○ No bleeding △ Slight bleeding × considerably bleeding Ink fixability After printing on a PET film without surface treatment, it was left for 1 minute. Thereafter, the printed portion was rubbed with a finger, and the degree of fixing of the ink was visually evaluated. ○ Almost no ink can be obtained △ Some ink can be obtained × Most of ink can be obtained After printing on recycled paper, it was left for 1 hour. Thereafter, the printed portion was immersed together with the paper in water for 10 seconds and pulled up. The bleeding degree and the density of the ink were visually evaluated. ○ There is no change in the degree of bleeding or density △ Slight bleeding or printing is slightly lighter × Large bleeding or printing is much lighter

The results are shown in Table 1. It can be seen that the water-based ink of the present invention does not bleed, is excellent in water resistance, and is excellent in ink fixability to ordinary paper such as recycled paper which is not particularly subjected to surface treatment.

[0044]

[Table 1]

[0045]

The water-based ink of the present invention has a low ink bleeding, excellent water resistance, and excellent ink fixability. It is a water-based ink useful as an ink for ink-jet recording.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsuhiro Ishikawa 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside JSR Corporation

Claims (2)

[Claims] 1. An emulsion of a polymer obtained by sulfonating a polymer or copolymer containing a diene compound as a constituent unit or a hydrogenated product thereof, and 2) at least one selected from a dye or a pigment. A water-based ink comprising a seed. 2. A polymer obtained by sulfonating a polymer or copolymer containing a diene compound as a constitutional unit or a hydrogenated product thereof, emulsified and dispersed in water in the presence of a dye or a pigment. The water-based ink according to claim 1, wherein: