JP2011074321A - Ink composition for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink for inkjet recording, excellent in a color developability and a fixability and also excellent in delivery stability and clogging recoverability. <P>SOLUTION: The inkjet ink comprises: C.I. pigment green 36; a dispersing agent containing a copolymerization resin selected from the group consisting of a styrene-(meth)acrylic acid copolymerization resin, a styrene-methylstyrene-(meth)acrylic acid copolymerization resin or a styrene-maleic acid copolymerization resin, a (meth)acrylic acid-(meth)acrylate copolymerization resin and a styrene-(meth)acrylic acid-(meth)acrylate copolymerization resin, and a urethane resin; 70 wt.% or more of an alkyl (meth)acrylate containing ethyl acrylate and/or a cyclic alkyl (meth)acrylate, (meth)acrylic acid; and an ethylenic unsaturated monomer having a saturated or unsaturated ring. The inkjet ink contains polymer fine particles having a glass transition temperature of 0°C or lower and an acid value of 50 mgKOH/g or lower. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

Background of the Invention

FIELD OF THE INVENTION The present invention relates to an ink composition for ink jet recording, and more particularly, as an ink jet recording ink for textiles, it is excellent in color development and fixing properties, as well as in ejection stability and clogging recovery. The present invention relates to an ink composition for ink jet recording.

BACKGROUND ART Pigments are used as colorants for ink jet recording inks because of their excellent fastness such as water resistance and light resistance. Since the pigment has poor solubility in water, a dispersing agent such as a surfactant or a polymer is added to the ink to improve the dispersion stability of the pigment. As the dispersant, a resin having both a hydrophobic part and a hydrophilic part, for example, a styrene-acrylic copolymer resin is generally used.

  By the way, the ink used for ink jet recording has various printing such as no bleeding, good drying, uniform printing on various recording media, and adjoining colors in multicolor printing. Quality is required. In order to improve the printing quality, various additives are usually added to the ink. For example, glycol ethers such as diethylene glycol monobutyl ether are added to the ink in order to improve the permeability to the recording medium and reduce bleeding (US Pat. No. 5,156,675: Patent Document 1). An acetylene glycol surfactant is added (US Pat. No. 5,183,502: Patent Document 2), or both are added (US Pat. No. 5,196,056). Patent Document 3).

  However, in the ink to which the pigment dispersant is added, if the above surfactants or glycol ethers are present in the ink, the dispersion resin is likely to be adsorbed and desorbed from the pigment, and the storage stability of the ink is insufficient. There was a case. Further, when the dispersant detached from the pigment remains in the ink, the ink viscosity increases, and the ink ejection stability and clogging recovery ability may be insufficient.

US Pat. No. 5,156,675 US Pat. No. 5,183,502 US Pat. No. 5,196,056

  The inventors of the present invention have excellent color development and fixing properties, particularly as an ink jet recording ink for textiles, by adding specific polymer fine particles to an ink composition containing a specific pigment dispersion. In addition, the inventors have obtained knowledge that an ink for ink jet recording that is excellent in ejection stability and clogging recovery can be realized. The present invention is based on such knowledge.

  Accordingly, an object of the present invention is to provide an ink composition for ink jet recording that is excellent in color development and fixability, and also excellent in ejection stability and clogging recovery properties, particularly as an ink jet recording ink for textiles.

The ink composition for ink jet recording according to the present invention is an ink composition for ink jet recording comprising at least a dispersion in which a pigment can be dispersed in water, and polymer fine particles,
The pigment is C.I. I. Pigment Green 36,
The dispersion is styrene- (meth) acrylic acid copolymer resin, styrene-methylstyrene- (meth) acrylic acid copolymer resin or styrene-maleic acid copolymer resin, (meth) acrylic acid- (meth) acrylic acid ester. A copolymer resin, a copolymer resin selected from the group consisting of a styrene- (meth) acrylic acid- (meth) acrylic ester copolymer resin, and a urethane resin,
The polymer fine particles are
As a monomer component, at least 70% by weight of alkyl (meth) acrylate and / or cyclic alkyl (meth) acrylate containing ethyl acrylate, (meth) acrylic acid, and ethylenically unsaturated having a saturated or unsaturated ring. A saturated monomer, having a glass transition temperature of 0 ° C. or lower and an acid value of 50 mgKOH / g or lower.

  According to the present invention, it is possible to realize an ink composition for ink jet recording that is excellent in color developing property and fixing property, and also excellent in ejection stability and clogging recovery property, particularly as an ink jet recording ink for textiles.

Detailed description of the invention

  The ink composition for ink-jet recording according to the present invention comprises a dispersion in which a pigment can be dispersed in water and polymer fine particles as essential components. Hereinafter, each component will be described.

<Polymer fine particles>
The fine polymer particles used in the inkjet recording ink according to the present invention include at least 70% by weight or more of alkyl (meth) acrylate and / or cyclic alkyl (meth) acrylate containing ethyl acrylate, (meth) acrylic acid, and saturation. Or it is obtained by copolymerizing the monomer component which contains an ethylenically unsaturated monomer which has an unsaturated ring at least. By including 70% by weight or more of alkyl (meth) acrylate and / or cyclic alkyl (meth) acrylate containing ethyl acrylate, the friction fastness of dry friction and wet friction when printed on textiles is improved. . Further, by containing an ethylenically unsaturated monomer having a saturated or unsaturated ring, the ink ejection stability is improved.

  As alkyl (meth) acrylate, C1-C24 alkyl (meth) acrylate is preferable, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate , Isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, diethyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (Meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, and the like can be used, and one or more of these can be used. , Including as an essential monomer component of the acrylate in the present invention. More preferably, ethyl acrylate is contained in an amount of 60 to 80% by weight as a monomer component. By including ethyl acrylate in the above range, color development and fixing properties are further improved when used for textiles.

  The cyclic alkyl (meth) acrylate is preferably an alkyl (meth) acrylate having 3 to 24 carbon atoms. For example, t-butylcyclohexyl (meth) acrylate, tetramethylpiperidyl (meth) acrylate, dicyclopentaniur (meth) ) Acrylate, dicyclopentenyloxy (meth) acrylate, and the like.

  Examples of the ethylenically unsaturated monomer having a saturated or unsaturated ring include styrene, α-methylstyrene, p-hydroxystyrene, o-chlorostyrene, and limonene. Among these, styrene is preferable.

  The content ratio of the alkyl (meth) acrylate and / or the cyclic alkyl (meth) acrylate and the ethylenically unsaturated monomer having a saturated or unsaturated ring is preferably 3: 1 to 10: 1. By setting both monomers within the above range, both fastness and ejection stability when printed on textiles can be achieved. When the content ratio of the ethylenically unsaturated monomer having a saturated or unsaturated ring is higher than the above range, the fastness may be lowered. Moreover, when the content ratio of alkyl (meth) acrylate and / or cyclic alkyl (meth) acrylate is higher than the above range, ejection stability may be lowered.

  The fine polymer particles obtained by copolymerizing the above monomers have a glass transition temperature of 0 ° C. or lower. By using polymer fine particles having a glass transition temperature of 0 ° C. or lower, the fixability of the pigment is improved and the ejection stability is particularly excellent as an inkjet recording ink for textiles. A preferable glass transition temperature is −5 ° C. to −25 ° C. The glass transition temperature means a value measured according to JIS K6900.

  The fine polymer particles used in the present invention have an acid value of 50 mgKOH / g or less. By using polymer fine particles having an acid value of 50 mgKOH / g or less, the fixability of the pigment is improved, and in particular, the fastness to washing when printed on textiles is improved. A preferable acid value is 30 mgKOH / g or less.

  The polymer fine particles used in the present invention are preferably composed of a polymer having a styrene-converted weight average molecular weight of 100,000 to 1,000,000 by gel permeation chromatography. By using polymer fine particles having a molecular weight of 100,000 or more, the fixability of the pigment is improved, and especially the fastness to washing when printed on textiles is improved. On the other hand, when the weight average molecular weight is less than 100,000, the fastness to washing tends to deteriorate, and when the molecular weight exceeds 1,000,000, the fixability tends to decrease and the ejection stability also tends to decrease. is there.

  The average particle size of the polymer fine particles is preferably 50 to 500 nm. By using the polymer fine particles having such an average particle size, both excellent color developability and fastness can be achieved. A more preferable average particle diameter is 60 to 300 nm. In the present invention, the average particle diameter is measured by a light scattering method, and means an average value of dispersion diameters (cumulative 50% diameter) as particles formed by polymer fine particles in ink, For example, it can be measured using Microtrac UPA (Microtrac Inc.).

  As a method of copolymerizing the above monomers, an alcohol solvent, a ketone solvent, an ether solvent, or a glycol ether solvent can be used as a solvent. However, since it is an aqueous pigment dispersion, the solvent is required to be removable later. As such a solvent, the following can be used. That is, examples of the alcohol solvent include methanol, ethanol, isopropanol, 1-butanol, tertiary butanol, isobutanol, diacetone alcohol and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of ether solvents include dibutyl ether, tetrahydrofuran, dioxane and the like. Examples of the glycol ether solvent include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, and butyl cellosolve.

  As radical polymerization initiators for polymerizing polymers, t-butyl peroxy (2-ethylhexanoate), di-t-butyl peroxide, t-butyl peroxybenzoate, t-butyl peroxy octoate, etc. Organic peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2′-azobisbutyrate, 2,2 ′ -Azo compounds such as azobis (2-methylbutyronitrile), potassium persulfate, sodium persulfate, and the like can be used, but the invention is not limited to them. It can also be used. The amount of radical polymerization initiator used is preferably 0.01 mol% or more and 5 mol% or less with respect to the monomer used in the polymerization. The polymerization temperature is not particularly limited, but is usually in the range of 30 to 100 ° C, and preferably in the range of 40 to 90 ° C. When the polymerization temperature is too low, it is necessary to take a long time for the polymerization of the monomer, and in some cases, the polymerization rate may decrease and a large amount of monomer may remain.

  The polymer fine particles used in the present invention are preferably contained in a larger amount than the pigment on a weight basis. By adding more polymer fine particles than the pigment by weight, the fixability of the pigment is improved, particularly as an inkjet recording ink for textiles.

<Pigment dispersion>
The ink composition according to the present invention comprises a dispersion in which a pigment can be dispersed in water by a polymer. As the pigment dispersion, in the present invention, a styrene- (meth) acrylic acid copolymer resin, a styrene-methylstyrene- (meth) acrylic acid copolymer resin, or a styrene-maleic acid copolymer resin, (meth) acrylic acid. -A copolymer resin selected from the group consisting of (meth) acrylic acid ester copolymer resins and styrene- (meth) acrylic acid- (meth) acrylic acid ester copolymer resins (hereinafter sometimes referred to simply as copolymer resins). And urethane resin. By using these pigment dispersants in combination with the above polymers, in addition to glossiness and bronzing prevention of color images, ejection stability, clogging prevention, color stability and high image quality comparable to silver salts are achieved. can do.

  The weight ratio of the copolymer resin and the urethane resin is preferably 1/2 to 2/1, and more preferably 1 / 1.5 to 1.5 / 1. By adding both resins in this range, it is possible to form an image having even more excellent gloss and bronzing prevention, and to maintain the storage stability of the ink.

  The copolymer resin may be a resin (styrene-acrylic acid resin) containing a polymer obtained by reacting styrene with acrylic acid or an ester of acrylic acid. Alternatively, the copolymer resin may be an acrylic acid-based water-soluble resin. Alternatively, a salt such as sodium, potassium, or ammonium may be used.

  The urethane resin has a urethane bond and / or an amide bond, from the viewpoint of achieving a color image having excellent glossiness while being compatible with glossiness of color images, prevention of bronzing, and storage stability of the ink composition, A resin having an acidic group is preferable.

  The urethane resin is a resin containing a polymer obtained by reacting a diisocyanate compound and a diol compound.

  Examples of the diisocyanate compound include aromatic aliphatic diisocyanate compounds such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, aromatic diisocyanate compounds such as toluylene diisocyanate and phenylmethane diisocyanate, and modified products thereof. .

  Examples of the diol compound include polyethers such as polyethylene glycol and polypropylene glycol, polyesters such as polyethylene abido and polybutylene abates, and polycarbonates.

  The urethane resin preferably has a carboxyl group.

  The weight ratio of the solid content of the pigment to the solid content other than the pigment (the former / the latter) is compatible with the glossiness of the color image, the prevention of bronzing, and the storage stability of the ink composition, and is further excellent in glossiness. From the viewpoint of forming a color image, it is preferably 100/20 to 100/80.

  The content of the copolymer resin is 100 parts by weight of the pigment from the viewpoint of achieving both color image glossiness, bronzing prevention, and storage stability of the ink composition while being able to form a color image having further excellent glossiness. On the other hand, it is preferably 10 to 50 parts by weight, and more preferably 10 to 35 parts by weight.

  The content of the urethane resin is 100% by weight with respect to 100 parts by weight of the pigment from the viewpoint of achieving color image glossiness, prevention of bronze, and storage stability of the ink composition and forming a color image having further excellent glossiness. The amount is preferably 10 to 40 parts by weight, and more preferably 10 to 35 parts by weight.

  The total amount of the copolymer resin and the urethane resin is 90 parts by weight or less (more preferably 70 parts by weight or less) with respect to 100 parts by weight of the pigment. In addition, the ink composition is preferable because it can achieve both the storage stability of the ink composition and can form a color image with more excellent gloss.

  The acid value of the copolymer resin is preferably 50 to 320 mgKOH / kg from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition and forming a color image having further excellent glossiness. g, more preferably 100 to 250 mg KOH / g.

  The acid value of the urethane resin is preferably 10 to 300 mgKOH / g from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition and forming a color image having further excellent glossiness. More preferably, it is 20-100 mgKOH / g.

  The weight-average molecular weight (Mw) of the copolymer resin is preferably from the viewpoint of achieving a color image having a glossy color image, prevention of bronzing, and storage stability of the ink composition, and an excellent glossiness. It is 2,000-30,000, More preferably, it is 2,000-20,000.

  The weight average molecular weight before crosslinking of the urethane resin is preferably 100 from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition and forming a color image having further excellent glossiness. It is -200,000, More preferably, it is 1000-50,000.

  The glass transition temperature of the copolymer resin is preferably 30 ° C. or higher from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition, and formation of a color image having further excellent glossiness. More preferably, it is 50-130 degreeC.

  The glass transition temperature of the urethane resin is preferably -50 to 200 from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition and forming a color image having further excellent glossiness. ° C, more preferably -50 to 100 ° C.

  The copolymer resin may be adsorbed to the pigment in the ink composition or in the pigment dispersion, or may be free. The gloss of the color image, prevention of bronzing, and storage stability of the ink composition The maximum particle size of the copolymer resin is preferably 300 nm or less, and the average particle size is more preferably 200 nm or less, and particularly preferably 100 nm or less, from the viewpoint of forming a color image with further excellent glossiness. More preferably.

  The urethane resin is dispersed in fine particles in the ink composition or in the pigment dispersion, and is adsorbed on the pigment. The glossiness of the color image, prevention of bronzing, and the ink composition From the viewpoint of forming a color image having both excellent storage stability and excellent glossiness, the maximum particle size of the urethane resin is preferably 300 nm or less, more preferably 200 nm or less, and particularly preferably 100 nm or less. It is more preferable that

  Furthermore, in the present invention, the epoxy resin having a glycidyl ether skeleton or the resin having an oxazoline group is added as a crosslinking agent, so that glossiness of a color image, prevention of bronzing, and storage stability of the ink composition are achieved. It is particularly preferable from the viewpoint of achieving a color image that is compatible with the properties and further excellent in glossiness.

  The crosslinking agent is preferably a resin that reacts with a carboxyl group (carboxyl group attack type resin) from the viewpoint of further improving dispersibility. For example, a polycarbodiimide type having a carbodiimide group in the molecule, an oxazoline type having an oxazoline group in the molecule, an aziridine type and the like can be mentioned.

  The amount of the crosslinking agent added is such that the copolymer resin and the urethane can be formed from the viewpoint of achieving color image glossiness, prevention of bronzing, and storage stability of the ink composition as well as formation of a color image having further excellent glossiness. The gel fraction is preferably 20% or more, more preferably 35% or more, based on the total carboxy groups of the resin.

  In addition, the amount of the crosslinking agent added is effective solid weight from the viewpoint of achieving color image glossiness, bronzing prevention, and storage stability of the ink composition, and capable of forming a color image having further excellent glossiness. The ratio (that is, the amount of the crosslinking agent / the total amount of the copolymer resin and the urethane resin) is preferably an amount that is 0.5 / 100 to 50/100, more preferably 0.5 / 100 to 40 /. The amount is 100.

  The weight average molecular weight of the urethane resin reacted with the cross-linking agent is, from the viewpoint of forming a color image having a glossy color image, preventing bronzing, and the storage stability of the ink composition and having a further excellent glossiness. It is preferably 10,000 or more, and more preferably 30,000 or more.

  The pigment dispersion as described above is present in the ink as fine particles having an average particle diameter of 20 to 300 nm. By using a pigment dispersion having such a particle size, both excellent color developability and fastness can be achieved. A preferable average particle diameter is 70 to 230 nm, and more preferably 80 to 130 nm.

<Pigment>
Examples of the pigment used in the ink composition for ink jet recording according to the present invention include C.I. I. Pigment Green 36 is preferably used. The polymer and C.I. I. By combining with Pigment Green 36, it is possible to obtain a green ink having both good color developability and high printing fastness, storage stability, ejection stability and clogging recovery.

  The amount of the pigment used in the ink jet recording ink of the present invention is preferably 0.5 to 30% by weight. If the addition amount is less than this, the print density cannot be ensured, and if the addition amount is more than this, the viscosity of the ink increases or structural viscosity is generated in the viscosity characteristics, and the ejection stability of the ink from the ink jet head tends to deteriorate. .

  The pigment is preferably added to the ink composition as a pigment dispersion in which the above dispersion resin is mixed, from the viewpoint of forming an image having excellent storage stability and glossiness of the ink composition.

  The method for producing a pigment dispersion includes a pretreatment step in which the pigment particle size is made fine and uniform by untreated or kneading treatment, and after adding a copolymer resin, the pigment is dispersed using a bead mill or a collision type jet mill. It is preferable to include a dispersion step of dispersing, and a post-treatment step of adding a urethane resin and a cross-linking agent in some cases and performing a cross-linking treatment. Further, after the pretreatment step and before the dispersion step, it is preferable to carry out a neutralization treatment by adding an alkaline compound to the pigment.

  In the dispersion step, the dispersion treatment is preferably carried out by a bead mill or a collision type jet pulverizer as described above. The bead mill may be either a miniaturizable type or a normal type. The dispersion treatment conditions are adjusted as appropriate, and the dispersion treatment is performed until the copolymer resin has the preferred particle size. In the dispersion treatment, an organic solvent may be added and kneaded as necessary. By this step, the copolymer resin is firmly fixed on the surface of the pigment.

  After the dispersion step, it is preferable to go through an impurity removal step by ion exchange treatment or ultrafiltration treatment, followed by a post-treatment step. Ion exchange treatment can remove ionic substances such as cations and anions (divalent metal ions, etc.), and by ultra-treatment, impurities dissolved substances (residual substances during pigment synthesis, excess components in dispersion composition) , Resin not adsorbed on the organic pigment, contamination components, etc.) can be removed. In the ion exchange treatment, a known ion exchange resin is used. The ultratreatment uses a known ultrafiltration membrane and may be either a normal type or a double capacity up type.

  In the post-treatment step, by adding a urethane resin and a crosslinking agent to cause a crosslinking reaction, the copolymer resin and the urethane resin are crosslinked by the crosslinking agent and coat the surface of the pigment (encapsulation). Improves stability, lowers viscosity, and improves adhesion, and stabilizes the pigment dispersion.

<Water and other ingredients>
The ink composition according to the present invention comprises water as a main solvent. As the water, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. In addition, the use of water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold or bacteria can be prevented when the ink composition is stored for a long period of time.

  The ink composition according to the present invention preferably further comprises 1,2-alkylene glycol. By adding 1,2-alkylene glycol, bleeding is reduced, print quality is improved, and color development is also improved by using the polymer fine particles and the dispersion resin together. 1,2-alkylene glycol includes 1,2-alkylene having 5 or 6 carbon atoms such as 1,2-hexanediol, 1,2-pentanediol, 4-methyl-1,2-pentanediol, and the like. Glycol is preferred. Among these, 1,2-hexanediol and 4-methyl-1,2-pentanediol having 6 carbon atoms are more preferable. The amount of 1,2-alkylene glycol added is preferably 0.3 to 30% by weight, more preferably 0.5 to 10% by weight, based on the entire ink.

  In addition, the ink composition according to the present invention is compatible with water and contains a pigment, a pigment dispersant, the above-described polymer, and the above-described pH adjuster and various components described later, which are contained in the ink composition. It is preferable to include a water-soluble organic solvent that is stably dissolved or dispersed and held.

  Preferred examples of the water-soluble organic solvent include improved solubility of glycol ethers having low solubility in water and other components, further improved permeability to a recording medium (for example, paper), and nozzle clogging. As a function that can be expected to prevent water, alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl Ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, die Lenglycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1- Methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, Dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether , Glycol ethers such as dipropylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, triacetin , Sulfolane, and mixtures thereof.

  In the present invention, among the permeable organic solvents described above, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, diethylene glycol monopentyl ether, triethylene glycol monopentyl ether, diethylene glycol monohexyl Ether or triethylene glycol monohexyl ether is more preferable. By using the above-mentioned polymer and polymer dispersant together with these glycol ethers, bleeding can be further reduced and printing quality is improved.

  Furthermore, saccharides can be used for the same purpose. Examples include monosaccharides and polysaccharides, in addition to glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitol, maltose, cellobiose, sucrose, trehalose, maltotriose, etc. Alginic acid and its salts, cyclodextrins, and celluloses can be used. The amount added may be appropriately determined, but is preferably 0.05% by weight or more and 30% by weight or less. By being in the above range, even when the ink composition is dried at the tip of the head, the clogging can be easily recovered, and the viscosity of the ink composition capable of stable printing can be easily realized. Can do. According to a preferred embodiment of the present invention, more preferable addition amount of glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitolose, maltose, cellobiose, sucrose, trehalose, maltotriose is 3-20. % By weight. In addition, since addition of alginic acid, its salt, and cellulose tends to increase the viscosity of the ink composition, attention must be paid to the addition amount.

  The ink composition according to the present invention preferably contains a surfactant in order to control its permeability. The surfactant to be added is preferably compatible with other components in the ink composition. Further, a surfactant having high penetrability and stability is preferable. As the surfactant, amphoteric surfactants and nonionic surfactants are preferably used.

  Preferred examples of amphoteric surfactants include lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine and others Examples include imidazoline derivatives.

  Preferred examples of nonionic surfactants include acetylene glycol surfactants, acetylene alcohol surfactants, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl. Ethers such as allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxyethylene oleic acid ester, polyoxyethylene distearic acid ester , Sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxye Examples include ester surfactants such as lenmonooleate and polyoxyethylene stearate, silicon surfactants such as dimethylpolysiloxane, fluorine-containing surfactants such as other fluorine alkyl esters and perfluoroalkyl carboxylates, and the like. In particular, acetylene glycol surfactants and acetylene alcohol surfactants are preferred. When these surfactants are added to the ink composition, they are preferable because they have a low foaming property and an excellent antifoaming function. Specific examples of the acetylene glycol surfactant and the acetylene alcohol surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne- 3,6-diol, 3,5-dimethyl-1-hexyn-3ol and the like are available, and are also commercially available. For example, Surfynol 61, 82, 104, 465 manufactured by Air Products (UK) , 485, TG, Olphine STG from Nissin Chemical Industry Co., Ltd., Olfin E1010, and the like.

  The addition amount of the surfactant is preferably 0.01% by weight or more and 3% by weight or less with respect to the total amount of the ink composition, the more preferable upper limit value is 2.0% by weight, and the preferable lower limit value is 0.05% by weight.

  In the present invention, among the surfactants described above, it is preferable to use an acetylene glycol surfactant and / or an acetylene alcohol surfactant. By using an acetylene glycol surfactant and / or an acetylene alcohol surfactant, bleeding is further reduced and printing quality is improved. The acetylene glycol surfactant and / or acetylene alcohol surfactant used in the present invention is 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-. Alkylene oxide adducts of tetramethyl-5-decin-4,7-diol and alkylene oxide adducts of 2,4-dimethyl-5-decyn-4-ol and 2,4-dimethyl-5-decyn-4-ol 1 or more types selected from are preferred. These acetylene glycol surfactants and / or acetylene alcohol surfactants are available as E series such as Olfin 104 series and Olfine E1010 from Air Products, Surfinol 465 or Surfinol 61 from Nissin Chemical Industry Co., Ltd. Is possible. Addition of these improves the drying property of printing, and enables high-speed printing.

  In addition, the ink composition according to the present invention includes 1,2-alkylene glycol and acetylene glycol surfactant and / or acetylene alcohol surfactant, glycol ether and acetylene glycol surfactant and / or acetylene alcohol surfactant. Bleeding is further reduced by using a plurality of agents.

  The ink composition according to the present invention may be added with a pH buffer, an antioxidant, an ultraviolet absorber, an antiseptic or antifungal agent, a chelating agent, and the like, if necessary. Specific examples of the pH buffering agent include collidine, imidazole, phosphoric acid, 3- (N-morpholino) propanesulfonic acid, tris (hydroxymethyl) aminomethane, boric acid and the like.

  Specific examples of the antioxidant or ultraviolet absorber include allophanates such as allophanate and methyl allophanate, biurets such as biuret, dimethylbiuret and tetramethylbiuret, L-ascorbic acid and its salts, etc., manufactured by Ciba Geigy Examples include Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor 252, 153, Irganox 1010, 1076, 1035, MD1024, or lanthanide oxides.

  Specific examples of preservatives or fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3- ON (Proxel GXL, Proxel XL-2, Proxel LV, Proxel AQ, Proxel BD20, Proxel DL from Arch Chemicals) and the like. Specific examples of the chelating agent include ethylenediaminetetraacetic acid (EDTA).

<Method for producing ink composition>
The ink composition according to the present invention may be prepared by supplying and dispersing the above-described components to a dispersing / mixing machine (for example, a ball mill, a sand mill, an attritor, a basket mill, a roll mill, etc.). According to a preferred embodiment of the present invention, it is preferable to filter the ink stock solution obtained by the above-described dispersing / mixing device using a filter such as a membrane filter or a mesh filter to remove coarse particles.

<Inkjet recording method and apparatus>
The ink jet recording method using the ink composition according to the present invention is to perform printing by ejecting droplets of the ink composition and attaching the droplets to a heated recording medium. As an example of a method for ejecting ink composition droplets, for example, an electrostrictive element is used to convert an electrical signal into a mechanical signal, and ink stored in the nozzle head portion is intermittently ejected onto the surface of the recording medium. A method of recording characters and symbols, ink heated in the nozzle head portion is heated rapidly at a location very close to the discharge portion, bubbles are generated, and the ink is intermittently discharged by the volume expansion caused by the bubbles, and characters are printed on the surface of the recording medium. And a method of recording symbols. In the present invention, ejection is preferably performed by a method using an electrostrictive element that does not depend on heating, such as a piezo element. When a heating element such as a thermal head is used, the added polymer or the polymer as the pigment dispersant may change in quality and discharge may become unstable. In particular, when a large amount of ink is ejected over a long period of time, such as an inkjet ink for textiles, it is preferably ejected by a method using an electrostrictive element that does not depend on heating.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited to these.

<Preparation of polymer fine particles>
Emulsion A
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer solution containing 0.05 part of sodium lauryl sulfate, 30 parts of ethyl acrylate, 8 parts of butyl acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water, A primary material was prepared by adding dropwise to the reaction. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 40 parts of ethyl acrylate, 5 parts of butyl acrylate, 2 parts of methacrylic acid A reaction solution consisting of 10 parts of styrene, 10 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle aqueous dispersion (EM-A) was obtained by filtering with a 3 micrometer filter. A part of the polymer fine particle aqueous dispersion was collected and dried, and then the glass transition temperature was measured by a differential scanning calorimeter (EXSTAR6000DSC, manufactured by Seiko Denshi Kogyo Co., Ltd.). Moreover, it was 200,000 when the styrene conversion molecular weight when measuring a solvent as THF was measured using the GPC measuring apparatus (L7100, Hitachi Ltd. make). Moreover, the acid value by the titration method was 10 mgKOH / g.

Emulsion B
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer solution containing 0.05 part of sodium lauryl sulfate, 30 parts of ethyl acrylate, 5 parts of butyl acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water, A primary material was prepared by adding dropwise to the reaction. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 43 parts of ethyl acrylate, 1 part of hydroxyethyl methacrylate, acrylic acid A reaction solution consisting of 1 part, 15 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle water dispersion (EM-B) was obtained by filtering with a 3 micrometer filter. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-B were measured in the same manner as described above, they were -13 ° C, 220,000, and 10 mgKOH / g, respectively.

Emulsion C
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. In addition, 0.05 parts of sodium lauryl sulfate, 30 parts of ethyl acrylate, 10 parts of butyl acrylate, 8 parts of ethyl carbitol acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan are added to 7 parts of ion-exchanged water. The monomer solution was added dropwise at 70 ° C. to react to prepare a primary substance. To this primary substance, 2 parts of 10% ammonium persulfate solution was added and stirred, and further 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 30 parts of ethyl acrylate, 5 parts of butyl acrylate, acrylic acid 2 A reaction solution consisting of 10 parts of styrene, 10 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle aqueous dispersion (EM-C) was obtained by filtering with a 3 micrometer filter. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-C were measured in the same manner as described above, they were -10 ° C, 190,000, and 10 mgKOH / g, respectively.

Emulsion D
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer comprising 0.05 part of sodium lauryl sulfate, 30 parts of ethyl acrylate, 10 parts of butyl acrylate, 3 parts of butyl methacrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water. The solution was reacted dropwise at 70 ° C. to prepare the primary material. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 30 parts of ethyl acrylate, 11 parts of butyl acrylate, 1 part of acrylic acid A reaction solution consisting of 10 parts of styrene, 10 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle aqueous dispersion (EM-D) was obtained by filtering with a 3 micrometer filter. When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-D were measured in the same manner as described above, they were −7 ° C., 150,000, and 10 mgKOH / g, respectively.

Emulsion E
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer solution containing 0.05 part of sodium lauryl sulfate, 35 parts of ethyl acrylate, 3 parts of butyl acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water, A primary material was prepared by adding dropwise to the reaction. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 35 parts of ethyl acrylate, 3 parts of butyl acrylate, 5 parts of acrylic acid A reaction solution consisting of 10 parts of styrene, 10 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle water dispersion (EM-E) was obtained by filtering with a 3 micrometers filter. The glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-E were measured in the same manner as described above, and were -5 ° C, 200,000, and 50 mgKOH / g, respectively.

Emulsion F
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer solution containing 0.05 part of sodium lauryl sulfate, 40 parts of ethyl acrylate, 3 parts of 2-ethylhexyl acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water, A primary substance was prepared by adding dropwise and reacting at 70 ° C. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 40 parts of ethyl acrylate, 2 parts of butyl acrylate, 5 parts of methacrylic acid A reaction solution consisting of 5 parts of styrene, 5 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to a pH of 8 to 8.5. The polymer fine particle aqueous dispersion (EM-F) was obtained by filtering with a 3 micrometer filter. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-F were measured in the same manner as described above, they were -23 ° C, 300,000, and 30 mgKOH / g, respectively.

Emulsion G
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. In addition, a monomer solution in which 0.05 part of sodium lauryl sulfate, 40 parts of ethyl acrylate, 5 parts of styrene, and 0.02 part of t-dodecyl mercaptan are added dropwise to 7 parts of ion-exchanged water at 70 ° C. is reacted. Primary material was prepared. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 48 parts of ethyl acrylate, 3 parts of methacrylic acid, 4 parts of styrene , A reaction solution consisting of 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, neutralized with sodium hydroxide to pH 8 to 8.5, and filtered through a 0.3 μm filter. As a result, an aqueous polymer fine particle dispersion (EM-G) was obtained. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-G were measured in the same manner as described above, they were -19 ° C, 250,000, and 20 mgKOH / g, respectively.

Emulsion H
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. In addition, 0.05 parts of sodium lauryl sulfate, 30 parts of ethyl acrylate, 5 parts of methyl acrylate, 4 parts of ethyl carbitol acrylate, 5 parts of styrene and 0.02 part of t-dodecyl mercaptan are added to 7 parts of ion-exchanged water. The monomer solution was added dropwise at 70 ° C. to react to prepare a primary substance. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 20 parts of ethyl acrylate, 15 parts of butyl acrylate, hydroxyethyl methacrylate A reaction solution consisting of 10 parts, 1 part of methacrylic acid, 10 parts of styrene, and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by neutralization with sodium hydroxide, and pH of 8-8. And filtered through a 0.3 μm filter to obtain a polymer fine particle aqueous dispersion (EM-H). When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-H were measured in the same manner as described above, they were −7 ° C., 210,000, and 10 mgKOH / g, respectively.

Emulsion I
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer comprising 0.05 parts of sodium lauryl sulfate, 30 parts of ethyl acrylate, 5 parts of methyl acrylate, 2 parts of butyl methacrylate, 10 parts of styrene and 0.02 part of t-dodecyl mercaptan in 7 parts of ion-exchanged water. The solution was reacted dropwise at 70 ° C. to prepare the primary material. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 30 parts of ethyl acrylate, 4 parts of methyl acrylate, hydroxyethyl methacrylate A reaction solution consisting of 3 parts, 1 part of methacrylic acid, 15 parts of styrene and 0.5 part of t-dodecyl mercaptan was added with stirring at 70 ° C., followed by polymerization reaction, and then neutralized with sodium hydroxide to pH 8-8. And a polymer fine particle water dispersion (EM-I) was obtained by filtration with a 0.3 μm filter. When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-I were measured in the same manner as described above, they were −2 ° C., 160,000, and 10 mgKOH / g, respectively.

Emulsion J
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. In addition, a monomer solution in which 0.05 part of sodium lauryl sulfate, 40 parts of ethyl acrylate, 4 parts of styrene, and 0.02 part of t-dodecyl mercaptan are added dropwise to 7 parts of ion exchange water is dropped to 70 ° C. to react. Primary material was prepared. To this primary substance, 2 parts of 10% ammonium persulfate solution was added and stirred, and further 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 40 parts of ethyl acrylate, 10 parts of 2-ethylhexyl acrylate, acrylic A reaction solution consisting of 1 part of acid, 5 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to pH 8 to 8.5. The polymer fine particle aqueous dispersion (EM-J) was obtained by filtering with a 0.3 micrometer filter. When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-J were measured in the same manner as described above, they were −27 ° C., 230,000, and 20 mgKOH / g, respectively.

Emulsion K
In a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer, 100 parts of ion-exchanged water is added, and 0.2 parts of superoxide of polymerization initiator is added at 70 ° C. in a nitrogen atmosphere while stirring. A monomer solution in which 0.05 part of sodium lauryl sulfate, 30 parts of ethyl acrylate, 10 parts of butyl acrylate, 7 parts of ethyl carbitol acrylate, and 0.02 part of t-dodecyl mercaptan are added to 7 parts of ion-exchanged water. The primary substance was prepared by adding dropwise and reacting at 70 ° C. To this primary substance, 2 parts of a 10% ammonium persulfate solution was added and stirred. Further, 30 parts of ion-exchanged water, 0.2 part of potassium lauryl sulfate, 40 parts of ethyl acrylate, 5 parts of methyl acrylate, 2 parts of methacrylic acid A reaction solution consisting of 5 parts of styrene, 6 parts of styrene and 0.5 part of t-dodecyl mercaptan was added at 70 ° C. with stirring, followed by polymerization reaction, and then neutralized with sodium hydroxide to adjust the pH to 8 to 8.5. The polymer fine particle aqueous dispersion (EM-K) was obtained by filtering with a 3 micrometers filter. The glass transition temperature, styrene equivalent molecular weight, and acid value of EM-K were measured in the same manner as described above, and were -10 ° C., 270,000, and 10 mgKOH / g, respectively.

Emulsion L
In the emulsion A, an aqueous polymer fine particle dispersion (EM-L) was obtained in the same manner except that the total amount of ethyl acrylate was changed to hydroxyethyl methacrylate and the total amount of butyl acrylate was changed to ethyl carbitol acetate. The glass transition temperature, styrene equivalent molecular weight, and acid value of EM-L were measured in the same manner as described above, and were -9 ° C, 180,000, and 10 mgKOH / g, respectively.

Emulsion M
In the emulsion B, a polymer fine particle aqueous dispersion (EM-M) was obtained in the same manner except that the total amount of acrylic acid was changed to hydroxyethyl methacrylate. When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-M were measured in the same manner as described above, they were -11 ° C, 160,000, and 10 mgKOH / g, respectively.

Emulsion N
In the emulsion C, a polymer fine particle aqueous dispersion (EM-N) was obtained in the same manner except that the total amount of styrene was changed to ethyl carbitol acrylate. The glass transition temperature, styrene equivalent molecular weight, and acid value of EM-N were measured in the same manner as described above, and were found to be -14 ° C, 240,000, and 10 mgKOH / g, respectively.

Emulsion O
In the same manner as in emulsion D, except that the total amount of butyl acrylate was changed to ethyl carbitol acrylate, a polymer fine particle aqueous dispersion (EM-O) was obtained. When the glass transition temperature, the styrene equivalent molecular weight, and the acid value of EM-O were measured in the same manner as described above, they were 2 ° C., 170,000, and 10 mgKOH / g, respectively.

Emulsion P
In the same manner as in emulsion E, except that acrylic acid was changed to 7 parts and butyl acrylate was changed to 4 parts, an aqueous polymer fine particle dispersion (EM-P) was obtained. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-P were measured in the same manner as described above, they were −3 ° C., 230,000, and 60 mgKOH / g, respectively.

Emulsion Q
A monomer solution comprising 30 parts of benzyl acrylate, 1 part of acrylic acid and 0.12 part of t-dodecyl mercaptan in a reaction vessel equipped with a dropping device, a thermometer, a water-cooled reflux condenser, and a stirrer in a nitrogen atmosphere at 70 ° C. And heated to 70 ° C., and 61 parts of benzyl acrylate, 6 parts of acrylic acid, 2 parts of butyl acrylate, 0.4 part of t-dodecyl mercaptan and 0.4 part of sodium persulfate were added to the dropping funnel. The reaction was added dropwise to the reaction solution for reaction. Further, 130 parts of water was added to the reaction vessel and stirred, and then neutralized with sodium hydroxide, adjusted to pH 8 to 8.5, and filtered through a 0.3 μm filter to obtain a polymer fine particle aqueous dispersion (EM- Q) was obtained. When the glass transition temperature, styrene equivalent molecular weight, and acid value of EM-Q were measured in the same manner as described above, they were 40 ° C., 200,000, and 20 mgKOH / g, respectively.

なお、表中、ＥＡはエチルアクリレートを、ＭＡはメチルアクリレートを、ＢＡはブチルアクリレートを、ＢＭＡはブチルメタクリレートを、２−ＥＨＡは２−エチルヘキシルアクリレートを、ＨＥＭＡはヒドロキシエチルメタクリレートを、ＥＣＡはエチルカルビトールアクリレートを、ＡＡはアクリル酸を、ＭＡＡはメタクリル酸を、Ｓｔはスチレンを、ＢｚＡはベンジルアクリレートを意味する。 With respect to the obtained emulsions A to Q, details and physical properties of each constituent monomer are as shown in Table 1 below.

In the table, EA is ethyl acrylate, MA is methyl acrylate, BA is butyl acrylate, BMA is butyl methacrylate, 2-EHA is 2-ethylhexyl acrylate, HEMA is hydroxyethyl methacrylate, and ECA is ethyl carbyl. Tall acrylate, AA means acrylic acid, MAA means methacrylic acid, St means styrene, and BzA means benzyl acrylate.

<Preparation of pigment dispersion>
As a pigment, C.I. I. 20 parts of Pigment Green 36, 3 parts of a styrene-methylstyrene-acrylic acid copolymer (acid value 160 mgKOH / g, weight average molecular weight 8000, glass transition temperature 75 ° C.), 15 parts of glycerin, and isopropyl alcohol 4 parts were charged into a pressure kneader and kneaded at room temperature for 10 hours to prepare a pigment kneaded product.

  Next, 42 parts of the above-mentioned pigment kneaded product, 3 parts of triethanolamine as a neutralizing agent, and 55 parts of ion-exchanged water were charged into a stirrer, and the mixture was heated and stirred at 95 ° C. for 2 hours. Produced. This pre-pigment dispersion adjustment liquid was successively charged into a bead mill capable of making fine particles (having the ability to produce 50 nm organic pigment fine particles) and subjected to a 3-pass treatment to prepare a post-pigment dispersion preparation. The obtained pigment-dispersed preparation was adjusted to pH 8.5 with sodium hydroxide, centrifuged at 25000 G for 5 minutes to remove coarse particles, and a re-adjusted product was prepared after pigment dispersion.

  Next, 100 parts of the obtained post-dispersion re-adjusted product, 10 parts of a polyester polyurethane resin (solid content 30%, acid value 50 mg KOH / g, triethylamine neutralized), and 20% glycidyl ether as a crosslinking agent are used as a skeleton. 8 parts of an epoxy resin (epoxy equivalent 200 g / eq, acid value 50 mg KOH / g, triethylamine neutralized) is charged into a stirrer and stirred at 90 ° C. for 5 hours to crosslink the resin in the dispersion to obtain a crosslinked preparation. Got. Subsequently, a pigment dispersion was obtained by adjusting with ion-exchanged water and potassium hydroxide so that the pigment solid content concentration was 10% and the pH was about 9.

  The obtained pigment dispersion was about 15 parts of styrene-methylstyrene-acrylic acid copolymer and about 15 parts of polyester polyurethane resin with respect to 100 parts of pigment.

<Preparation of ink composition>
Using the polymer fine particle solution and the pigment dispersion obtained as described above, ink for ink jet recording was prepared according to the composition shown in Table 2 below. As water, 0.05% of the top side 240 (manufactured by Permachem Asia Co., Ltd.) is used to prevent ink corrosion, 0.02% of benzotriazole is used to prevent corrosion of inkjet head members, and the influence of metal ions in the ink system In order to reduce the concentration, 0.04% EDTA (ethylenediaminetetraacetic acid) · 2Na salt was added to ion-exchanged water.

なお、表中、括弧内の数値は、顔料分散体における顔料（固形分）濃度を意味し、ＴＥＧｍＢＥは、トリエチレングリコールモノブチルエーテルを意味する。また、サーフィノール６１、サーフィノール１０４、サーフィノール４６５は、エアープロダクツ社製の商品名である。

In the table, the numerical value in parentheses means the pigment (solid content) concentration in the pigment dispersion, and TEGmBE means triethylene glycol monobutyl ether. Surfinol 61, Surfinol 104, and Surfinol 465 are trade names manufactured by Air Products.

<Evaluation of ink composition>
Dye fastness test For each ink obtained, using an inkjet printer (PX-G930, manufactured by Seiko Epson Corporation), solid printing is performed on a cotton cloth and heat-treated at 150 ° C. for 5 minutes to prepare a sample for dye fastness test. Produced. The obtained print sample was subjected to a dry and wet friction fastness test in accordance with a method according to Japanese Industrial Standard (JIS) JIS L0849: 2004 friction tester type II. The evaluation device was a Gakushin friction fastness tester (AB-301S, Tester Sangyo Co., Ltd.), and was rubbed 100 times with a load of 200 g. Further, with respect to the obtained print samples, the washing fastness test was evaluated by JIS L0844: 2005 B-5 method, and the dry cleaning test was evaluated by B method of JIS L0860: 1996. The evaluation results were as shown in Table 3 below.

For each of the obtained inks, an ink jet printer (PX-G930, manufactured by Seiko Epson Corporation) was used, and the character size of 11 was written in Microsoft Word on XeroxP paper A4 size manufactured by Fuji Xerox Co., Ltd. at 35 ° C. and 35% atmosphere. Standard and MSP Gothic were printed and evaluated at 1000 pages at a rate of 4000 characters / page. The evaluation criteria were as follows.

  AA when there is no printing disorder at all, A with printing disorder at one place, B with printing disorder at 2-3 places, C at 4-5 printing disorders, and 6 or more printing disorders The thing was set to D. The evaluation results were as shown in Table 3 below.

Claims (15)

An ink composition for ink-jet recording, comprising at least a dispersion in which a pigment can be dispersed in water, and polymer fine particles,
The pigment is C.I. I. Pigment Green 36,
The dispersion is styrene- (meth) acrylic acid copolymer resin, styrene-methylstyrene- (meth) acrylic acid copolymer resin or styrene-maleic acid copolymer resin, (meth) acrylic acid- (meth) acrylic acid ester. A copolymer resin, a copolymer resin selected from the group consisting of a styrene- (meth) acrylic acid- (meth) acrylic ester copolymer resin, and a urethane resin,
The polymer fine particles are
As a monomer component, at least 70% by weight of alkyl (meth) acrylate and / or cyclic alkyl (meth) acrylate containing ethyl acrylate, (meth) acrylic acid, and ethylenically unsaturated having a saturated or unsaturated ring. An ink composition for ink jet recording, comprising at least a saturated monomer, having a glass transition temperature of 0 ° C. or lower and an acid value of 50 mgKOH / g or lower.   The ink composition according to claim 1, wherein the alkyl (meth) acrylate is an alkyl (meth) acrylate having 1 to 24 carbon atoms.   The ink composition according to claim 1 or 2, wherein the cyclic alkyl (meth) acrylate is a cyclic alkyl (meth) acrylate having 3 to 24 carbon atoms.   The ink composition according to any one of claims 1 to 3, wherein the polymer fine particles comprise 60 to 80% by weight of ethyl acrylate as a monomer component.   The content ratio of the alkyl (meth) acrylate and / or the cyclic alkyl (meth) acrylate and the ethylenically unsaturated monomer having a saturated or unsaturated ring is 3: 1 to 10: 1. The ink composition according to any one of the above.   The ink composition according to any one of claims 1 to 5, wherein the ethylenically unsaturated monomer having a saturated or unsaturated ring is styrene.   The ink composition according to any one of claims 1 to 6, wherein the polymer fine particles have a glass transition temperature of -5 to -25 ° C.   The ink composition according to any one of claims 1 to 7, wherein an acid value of the polymer fine particles is 30 mgKOH / g or less.   The ink composition according to any one of claims 1 to 8, wherein the polymer fine particles have a styrene-converted weight average molecular weight of 100,000 to 1,000,000 by gel permeation chromatography.   The ink composition according to any one of claims 1 to 9, wherein a weight ratio of the copolymer resin to the urethane resin in the dispersion resin is 1/2 to 2/1.   The ink composition according to any one of claims 1 to 10, wherein the polymer fine particles are contained in a larger amount than the pigment on a weight basis.   The ink composition according to claim 1, further comprising 1,2-alkylene glycol.   The ink composition according to any one of claims 1 to 12, further comprising an acetylene glycol surfactant and / or an acetylene alcohol surfactant.   The ink composition for ink jet recording according to any one of claims 1 to 13, which is used for ink jet textile printing.   The inkjet textile printing method using the ink composition as described in any one of Claims 1-14.