JP2015174876A - Aqueous pigment dispersion, textile printing method, and inkjet textile printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous pigment dispersion excellent in both washing fastness and rubbing fastness and to provide an ink for textile printing.SOLUTION: A pigment dispersant uses an urethane resin produced by reacting (a1-1) a polyester polyol as (a1) a polyol produced by reacting a polycarboxylic acid and a polyol, a polyol having a hydrophilic group which is an anionic group, a cationic group, a polyoxyethylene group, or a polyoxyethylene-polyoxypropylene group, and (a2) a polyisocyanate group. A method for producing an aqueous pigment dispersion comprises dispersing a pigment in a water-soluble solvent and/or water by use of the pigment dispersant. A textile printing method comprises printing the aqueous pigment dispersion produced by the production method on a fabric.

Description

  The present invention relates to an aqueous pigment dispersion particularly suitable for printing on fabric and a printing method using the same.

  As a printing method for printing images such as characters, pictures, designs, etc. on fabrics such as woven fabrics, nonwoven fabrics, and knitted fabrics, a pigment printing method using water-based pigment ink is known. The pigment printing method is a method in which a printing agent, which is a pigment composition composed of a color pigment and a binder resin, is printed and then fixed to a substrate through a drying and curing step as necessary. As this printing method, a silk screen method (for example, refer to Patent Document 1) in which a pattern of a screen candy is continuously printed on a cloth, or an ink jet recording method in which ink is ejected from a nozzle and adhered to the cloth (for example, refer to Patent Document 2). )It has been known.

  Compared to dye-based printing methods, pigment printing methods do not require the selection of colorants depending on the fiber type, the processing method is simple, and there is no need for steaming, water washing or soaping processes, so there is no energy cost. . Moreover, since no waste liquid is generated, it is a safe processing method in terms of environment. However, the pigment printing method is different from the printing method using a dye, and the pigment as the color material is physically fixed to the cloth with a binder resin, so that the printed portion is printed on the cloth by washing or external friction. There was a problem such as peeling off.

  The aqueous pigment dispersion is generally prepared from carbon black or a chromatic organic pigment and a synthetic resin such as a styrene resin, an acrylic resin, or a polyester resin. Recently, the use of a polyurethane resin excellent in dispersibility has been proposed as the synthetic resin.

  As such a polyurethane resin, for example, a polyether polyurethane resin having a poly (oxytetramethylene) structure and having an acid value of 40 to 90 (see Patent Document 3), a hydrophobic substance having an active hydrogen group and a molecular weight of 400 or more. A polyfunctional active hydrogen compound having three or more active hydrogen groups and a molecular weight of less than 400, and a hydrophilic group-containing active hydrogen compound having a hydrophilic group and an active hydrogen group An aqueous polyurethane resin (see Patent Document 4), which is obtained by a reaction between an active hydrogen component and a polyisocyanate component containing a polyisocyanate compound, is known.

  However, when the recording medium is paper or film, the pigment dispersion obtained by Patent Document 3 can obtain a colored image with excellent gloss, but when printed on a fabric, the fastness to washing and the fastness to friction are insufficient. It is. Also in Patent Document 4, although a pigment dispersion excellent in initial dispersibility and storage stability can be obtained, there is no disclosure about the characteristics of the printed matter.

JP 2007-332523 A JP 2009-215506 A JP 2005-290044 A JP 2008-101162 A

  An object of the present invention is to provide an ink for textile printing that exhibits excellent initial dispersibility and dispersion stability, and is excellent in washing fastness and friction fastness.

  The present inventors can use a urethane resin having a specific structure as a pigment dispersant, so that it can be used without any problem in the silk screen method or the ink jet recording method, and the initial dispersibility and dispersion stability are improved. It has been found that an aqueous pigment dispersion can be obtained which is excellent and provides a printed part having excellent fastness to washing and fastness to friction.

  That is, the present invention relates to a polyester polyol (a1-1) obtained by reacting a polycarboxylic acid and a polyol as the polyol (a1), an anionic group, a cationic group, a polyoxyethylene group, or a polyoxyethylene-polyoxypropylene. Provided is a pigment dispersant using a urethane resin obtained by reacting a polyol having a hydrophilic group as a group with a polyisocyanate (a2).

  The present invention also provides a method for producing an aqueous pigment dispersion in which a pigment is dispersed in a water-soluble solvent and / or water using the pigment dispersant described above.

  The present invention also provides a printing method for printing on a fabric the aqueous pigment dispersion obtained by the production method described above.

  The present invention also provides an ink-jet printing method for printing a water-based pigment dispersion obtained by the production method described above on a fabric.

  Since the pigment dispersant of the present invention uses a urethane resin having a polyester structure and a hydrophilic group in one molecule, it is excellent in initial dispersibility and dispersion stability, and the printed part has a fastness to washing and a fastness to friction. And an excellent aqueous pigment dispersion can be obtained. The aqueous pigment dispersion obtained by the present invention can be used without any problem whether it is a silk screen method or an ink jet recording method.

(Pigment dispersant)
The pigment dispersant of the present invention comprises a polyester polyol (a1-1) obtained by reacting a polycarboxylic acid and a polyol as the polyol (a1), an anionic group, a cationic group, a polyoxyethylene group or a polyoxyethylene- A urethane resin obtained by reacting a polyol having a hydrophilic group that is a polyoxypropylene group with polyisocyanate (a2) is used. (Hereinafter, this urethane resin is referred to as “urethane resin (A)”)

  The urethane resin (A) preferably has a weight average molecular weight of 5,000 to 200,000, more preferably 20,000 to 100,000, from the viewpoints of wash fastness and friction fastness.

  In the present invention, it is essential to use the urethane resin (A) having a polyester structure together with the hydrophilic group in order to improve the fastness to washing and the fastness to friction.

  The polyester structure is composed of an aliphatic, alicyclic or aromatic structure having an ester bond. It is preferable to use the said polyester structure in 10-90 mass% with respect to the total mass of the polyol (a1) and polyisocyanate (a2) used for manufacture of a urethane resin (A).

  Here, the aqueous pigment dispersion obtained by using the urethane resin (A) having a polyether structure instead of the polyester structure may cause a decrease in fastness to washing and fastness to friction.

  The polyester structure is preferably a structure derived from a polyester polyol obtained by an esterification reaction of a polycarboxylic acid and a low molecular weight polyol, and further having an aromatic structure, It is preferable for improvement.

In addition, the urethane resin (A) has a hydrophilic group for imparting dispersion stability in the aqueous pigment dispersion.
As said hydrophilic group, what is generally called an anionic group, a cationic group, and a nonionic group can be used, but it is preferable to use an anionic group or a cationic group among them.

  As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group and the like can be used. Among them, a carboxylate group partially or wholly neutralized with a basic compound or the like It is preferable to use a sulfonate group in order to maintain good water dispersibility.

  Examples of basic compounds that can be used for neutralizing the carboxyl group or sulfonic acid group as the anionic group include organic amines such as ammonia, triethylamine, pyridine, morpholine, alkanolamines such as monoethanolamine, Na, Metal base compounds containing K, Li, Ca and the like can be mentioned, and among these, neutralization with potassium hydroxide or an aqueous solution thereof is particularly preferable in providing environmentally friendly products.

Moreover, as said cationic group, a tertiary amino group etc. can be used, for example.
Examples of the acid that can be used when neutralizing a part or all of the tertiary amino group include formic acid and acetic acid. Moreover, as a quaternizing agent that can be used when quaternizing some or all of the tertiary amino groups, for example, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate can be used.

  Examples of the nonionic group include polyoxyalkylene groups such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly (oxyethylene-oxypropylene) group, and a polyoxyethylene-polyoxypropylene group. Can be used. Among these, it is preferable to use a polyoxyalkylene group having an oxyethylene unit in order to further improve the hydrophilicity.

  The hydrophilic group imparts better water dispersibility when present at 100 mmol / kg to 1200 mmol / kg with respect to the entire urethane resin (A), and has a range of 150 mmol / kg to 1000 mmol / kg. Is more preferable.

Further, the aqueous pigment dispersion of the present invention may use a crosslinking agent (F) described later for the purpose of further improving the fastness to washing and the fastness to friction. When using the said crosslinking agent (F), it is preferable to use what has functional group [X] which can carry out a crosslinking reaction with the functional group which the said crosslinking agent (F) has as said urethane resin (A).
Examples of the functional group [X] include a carboxyl group and a carboxylate group that can be used as the hydrophilic group. The carboxyl group or the like contributes to the water dispersion stability of the urethane resin (A) in the aqueous medium (C), and when they undergo a crosslinking reaction, they also act as the functional group [X], and the crosslinking agent (F) can be partially crosslinked.
When a carboxyl group or the like is used as the functional group [X], the urethane resin (A) preferably has an acid value of 2 to 50, and has an acid value of 5 to 40. It is preferable to improve washing fastness and friction fastness.

The urethane resin (A) can be produced, for example, by reacting a polyol (a1), a polyisocyanate (a2), and, if necessary, a chain extender.
As the polyol (a1), from the viewpoint of imparting a polyester structure to the urethane resin (A), a polyester polyol (a1-1) is used, and from the viewpoint of imparting a hydrophilic group to the urethane resin (A). A polyol having a hydrophilic group is used.

  Examples of the polyester polyol (a1-1) include polyesters obtained by esterification reaction of low molecular weight polyols and polycarboxylic acids, and polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone. Alternatively, these copolyesters can be used.

  Examples of the low molecular weight polyol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and 1,3-butane having a molecular weight of about 50 to 300. Aliphatic polyols such as diols, aliphatic cyclic structure-containing polyols such as cyclohexanedimethanol, bisphenol compounds such as bisphenol A and bisphenol F, and aromatic structure-containing polyols such as alkylene oxide adducts thereof can be used. .

  Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, and dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic anhydride, naphthalene-2,6-dicarboxylic acid, Naphthalene dicarboxylic acid such as naphthalene-2,7-dicarboxylic acid and naphthalene-1,5-dicarboxylic acid, aromatic polycarboxylic acid such as dimethyl terephthalate and orthophthalic acid, and anhydrides or ester-forming derivatives thereof Can be used.

  As the aromatic structure-containing polyester polyol that can be used as the polyester polyol (a1-1), for example, a combination of the low molecular weight polyol and the polycarboxylic acid that has an aromatic structure in one or both of them is used. Can be manufactured.

  Specifically, the aromatic structure-containing polyester polyol includes aliphatic polyols such as ethylene glycol, diethylene glycol, and 1,4-butanediol, and aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, and phthalic acid. It is preferable to use what is obtained by combining reaction. It can also be produced by reacting an aromatic structure-containing polyol such as bisphenol A with the aliphatic polycarboxylic acid.

The aromatic structure-containing polyester polyol has an aromatic cyclic concentration of 2.5 mol / kg or more contained in the total amount of the polyester polyol (a1-1) to be used, particularly from the viewpoint of fastness to washing and fastness to friction. It is preferable to use it so that the aromatic cyclic concentration is 3.0 mol / kg or more.
In addition, the said polyester polyol (a1-1) is 1 type of polyester polyol of the same kind (here, the same kind shows that parameters, such as the kind of polycarboxylic acid used as a raw material, a polyol, and molecular weight, are the same). Different types (here, “different types” means different types of polycarboxylic acid and polyol as raw materials, and different parameters such as molecular weight). There is no particular limitation.
In addition, what is necessary is just to calculate an aromatic cyclic density | concentration with respect to the total total amount of all the types of polyester polyols used for the aromatic cyclic density | concentration in the case of using multiple types of different polyester polyols.

  As said polyester polyol (a1-1), it is preferable to use what has the number average molecular weight of the range of 200-5000. Especially, as said aromatic structure containing polyester polyol, it is preferable to use what has a number average molecular weight of 250-3000, in order to improve washing fastness and friction fastness.

  Moreover, as said hydrophilic group containing polyol, anionic group containing polyol other than above-described polyester polyol (a1-1), a cationic group containing polyol, and a nonionic group containing polyol can be used, for example. Especially, it is preferable to use an anionic group containing polyol or a cationic group containing polyol, and it is more preferable to use an anionic group containing polyol.

As the anionic group-containing polyol, for example, a carboxyl group-containing polyol or a sulfonic acid group-containing polyol can be used.
Examples of the carboxyl group-containing polyol include 2,2'-dimethylolpropionic acid, 2,2'-dimethylolbutanoic acid, 2,2'-dimethylolbutyric acid, 2,2'-dimethylolvaleric acid, and dicarboxylic acids thereof. A carboxyl group-containing polyester polyol obtained by reacting with an acid can be used. Of these, 2,2′-dimethylolpropionic acid is preferably used.

  The carboxyl group-containing polyol is preferably used in the range where the acid value of the urethane resin (A) is 10 to 70, more preferably 10 to 50. In addition, the acid value said by this invention is the theoretical value computed based on the usage-amount of acid group containing compounds, such as a carboxyl group containing polyol used for manufacture of the said urethane resin (A).

The anionic groups are preferably partially or wholly neutralized with a basic compound or the like in order to exhibit good water dispersibility.
Examples of basic compounds that can be used for neutralizing the anionic group include organic amines having a boiling point of 200 ° C. or higher, such as ammonia, triethylamine, morpholine, monoethanolamine, and diethylethanolamine, NaOH, KOH, and LiOH. A metal hydroxide containing etc. can be used. The basic compound is preferably used in the range of basic compound / anionic group = 0.5 to 3.0 (molar ratio) from the viewpoint of improving the water dispersion stability of the resulting coating agent. It is more preferable to use in the range of 0.5 to 2.0 (molar ratio).

Further, as the cationic group-containing polyol, for example, a tertiary amino group-containing polyol can be used. Specifically, N-methyl-diethanolamine, a compound having two epoxies in one molecule, and a secondary amine. A polyol obtained by reacting with can be used.
It is preferable that a part or all of the cationic group is neutralized with an acidic compound such as formic acid, acetic acid, propionic acid, succinic acid, glutaric acid, tartaric acid and adipic acid.
Further, the tertiary amino group as the cationic group is preferably partly or entirely quaternized. As the quaternizing agent, for example, dimethyl sulfate, diethyl sulfate, methyl chloride, ethyl chloride and the like can be used, and dimethyl sulfate is preferably used.

  Further, as the nonionic group-containing polyol, polyalkylene glycol having a structural unit derived from ethylene oxide can be used.

  The hydrophilic group-containing polyol is preferably used in the range of 0.3% by mass to 10.0% by mass with respect to the total amount of polyol used for the production of the urethane resin (A).

Moreover, as said polyol, other polyol can be used as needed besides the above-mentioned polyol.
Examples of the other polyol include ethylene glycol, diethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, , 4-cyclohexanediol, 1,6-hexanediol, cyclohexanedimethanol and other relatively low molecular weight polyols can be used.

  Examples of the polyisocyanate (a2) that can react with the polyol include 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and the like. Aromatic polyisocyanates, aliphatic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, polyisocyanates containing an aliphatic cyclic structure such as cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate. use Door can be.

  The urethane resin (A) is produced, for example, by reacting the polyol (a1) with the polyisocyanate (a2) in the absence of a solvent or in the presence of an organic solvent, When there is a hydrophilic group in the urethane resin (A), it is produced by mixing a part or all of the hydrophilic group as necessary with an aqueous medium to make it aqueous. Can do. In addition, when using a chain extender as needed, the urethane resin (A) by which chain | stretch was extended | stretched can be manufactured by mixing with an aqueous medium in the case of the said water-ization.

  In the reaction of the polyol (a1) and the polyisocyanate (a2), for example, the equivalent ratio of the isocyanate group of the polyisocyanate (a2) to the hydroxyl group of the polyol (a1) is 0.8 to 2.5. Preferably, it is carried out in the range of 0.9 to 1.5.

  Examples of the organic solvent that can be used in producing the urethane resin (A) include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; acetate esters such as ethyl acetate and butyl acetate; acetonitrile Nitriles such as dimethylformamide and amides such as N-methylpyrrolidone can be used alone or in combination of two or more.

As a chain extender that can be used when the urethane resin (A) is produced, polyamine, other active hydrogen atom-containing compounds, and the like can be used.
Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 3,3′-. Diamines such as dimethyl-4,4′-dicyclohexylmethanediamine, 1,4-cyclohexanediamine, N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, hydrazine, N, N′-dimethylhydrazine, 1,6-hexamethylenebishydrazine, dihydrazisuccinate , Adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, β-semicarbazide propionic acid hydrazide, 3-semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazide methyl-3,5 , 5-trimethylcyclohexane can be used.

  Examples of the other active hydrogen-containing compound include ethylene glycol, diethylene recall, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, and sucrose. Glycols such as methylene glycol, glycerin and sorbitol; phenols such as bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylsulfone, hydrogenated bisphenol A, hydroquinone , And water can be used alone or in combination of two or more within a range in which the storage stability of the aqueous pigment dispersion of the present invention does not deteriorate.

  In addition, the urethane resin (A) produced by the above method can be made water-based by, for example, one hydrophilic group of the water-based urethane resin (A) obtained by reacting the polyol (a1) with the polyisocyanate (a2). After neutralization or quaternization of part or all, water can be added and dispersed in water. In that case, you may use an emulsifier as needed. In addition, when dissolving or dispersing water, a machine such as a homogenizer may be used as necessary.

  Examples of the emulsifier include nonionic emulsifiers such as polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene sorbitol tetraoleate, and polyoxyethylene / polyoxypropylene copolymer. Fatty acid salts such as sodium oleate, alkyl sulfates, alkylbenzene sulfonates, alkyl sulfosuccinates, naphthalene sulfonates, polyoxyethylene alkyl sulfates, alkane sulfonate sodium salts, sodium alkyl diphenyl ether sulfonates, etc. Anionic emulsifiers; Cationic emulsifiers such as alkylamine salts, alkyltrimethylammonium salts, and alkyldimethylbenzylammonium salts. It is.

  Examples of the aqueous medium include water, organic solvents miscible with water, and mixtures thereof. Examples of the organic solvent miscible with water include alcohols such as methanol, ethanol, n- and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol and propylene glycol; Alkyl ethers; lactams such as N-methyl-2-pyrrolidone, and the like. In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. From the viewpoint of safety and load on the environment, water alone or a mixture of water and an organic solvent miscible with water is preferable, and only water is particularly preferable.

  The urethane resin (A) thus obtained is in a state where the urethane resin (A) is dispersed in an aqueous medium. When used as a pigment dispersant, it is preferable that the urethane resin (A) is in the form of an aqueous dispersion dispersed in an aqueous medium as described above. At this time, the aqueous medium is contained in the range of 30% by mass to 90% by mass with respect to the total amount of the composition of the urethane resin (A) to obtain a composition excellent in water dispersion stability. Is preferable.

  When the aqueous pigment dispersion of the present invention is printed on a fabric by the ink jet method, the particle size of the aqueous dispersion of the urethane resin (A) is in the range of 5 nm to 1000 nm from the viewpoint of the dischargeability of the ink jet ink. Is preferable, and it is still more preferable that it is the range of 10 nm-400 nm.

  In preparing the aqueous pigment dispersion of the present invention, the nonvolatile content of the urethane resin is usually 20 to 100 parts, preferably 30 to 50 parts, based on 100 parts of the pigment in terms of mass. When the amount of the polyurethane resin relative to the pigment in the aqueous pigment dispersion is small, not only sufficient dispersion stability cannot be obtained, but also the fastness to washing after printing and the fastness to friction tend to decrease. On the other hand, if the amount is too large, it is difficult to use the aqueous pigment dispersion in terms of viscosity and fluidity, which is not preferable.

(Pigment)
The pigment used in the present invention is not particularly limited, and those usually used as pigments for screen recording inks and water-based inkjet recording inks can be used as colorants. Specifically, known inorganic pigments and organic pigments that can be dispersed in water or water-soluble organic solvents can be used. Examples of the inorganic pigment include carbon black produced by a known method such as titanium oxide, iron oxide, a contact method, a furnace method, and a thermal method. Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelates, acidic dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, and the like.

Specific examples of the pigment include carbon black, No. manufactured by Mitsubishi Chemical Corporation. 2300, no. 2200B, no. 900, no. 980, no. 33, no. 40, No, 45, No. 45L, no. 52, HCF88, MA7, MA8, MA100, etc. are Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc. manufactured by Columbia, Regal 400R, Regal 330R, Regal 660R, Mull 660R, Mull 660R Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. are Degussa's Color Black FW1, FW2, FW2V, FW18, FW200, S170, U, S150, S35, P , V, 1400U, Special Black 6 , 5, 4, 4A, NIPEX150, NIPEX160, NIPEX170, NIPEX180, and the like.
Specific examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like.
Specific examples of pigments used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 146, 168, 176, 184, 185, 202, 209, etc. It is done.
Specific examples of pigments used for cyan ink include C.I. I. Pigment blue 1, 2, 3, 15, 15: 3, 15: 4, 16, 22, 60, 63, 66, and the like.

  As the pigment used in the present invention, either dry powder or wet cake can be used. Moreover, these pigments may be used independently and may be used in combination of 2 or more types.

The pigment used in the present invention is preferably a pigment having a particle size of 25 μm or less, and particularly preferably a pigment having a particle size of 1 μm or less. When the particle diameter is within this range, pigment settling hardly occurs and the pigment dispersibility is good.
For the measurement of the particle diameter, for example, a value measured using a transmission electron microscope (TEM) or a scanning electron microscope (SEM) can be adopted.

(Water-soluble solvent and / or water)
As the water-soluble solvent and / or water used in the present invention, any conventionally used water-based ink for ink jet recording can be used.
Examples of the water-soluble solvent include mono- or polyhydric alcohols, amides, ketones, keto alcohols, cyclic ethers, glycols, polyhydric alcohol lower alkyl ethers, polyalkylene glycols, glycerin, N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1 , 3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, trimethylolpropane, pentaerythritol and other polyols, Polyhydric alcohol alkyl ethers such as ethylene glycol monobutyl ether and tetraethylene glycol monomethyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, and polyhydric alcohol aralkyl ethers, 2-pyrrolidone, Lactams such as N-methyl-2-pyrrolidone and ε-caprolactam, 1,3-dimethylimidazolidinone acetone, N-methyl-2-pyrrolidone, m-butyrolactone, polyoxyalkylene adduct of glycerin, propylene glycol monomethyl ether acetate Dimethyl sulfoxide, diacetone alcohol, dimethylformamide, propylene glycol monomethyl ether, and the like. These may be used alone or in combination of two or more.

  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.

(Method for producing aqueous pigment dispersion)
The aqueous pigment dispersion of the present invention can be prepared by mechanically forcibly dispersing the pigment in a urethane resin. Further, the aqueous pigment dispersion can be prepared as a pigment paste (high-concentration aqueous dispersion) by diluting it with a water-soluble solvent and / or water and adding other additives as necessary.

The method for obtaining the pigment paste by dispersing the pigment in the water-soluble solvent and / or water is not particularly limited, and it is preferable to use a known dispersion method.
Examples of the dispersion method include the following (1) to (3).
(1) A method of preparing a pigment paste by adding a pigment to an aqueous medium containing a pigment dispersant and water and then dispersing the pigment in the aqueous medium using a stirring / dispersing device.
(2) The pigment and the pigment dispersant are kneaded using a kneader such as two rolls or a mixer, and the resulting kneaded product is added to an aqueous medium containing water, and the pigment is then mixed using a stirring / dispersing device. A method of preparing a paste.
(3) After adding a pigment to a solution obtained by dissolving a pigment dispersant in an organic solvent compatible with water such as methyl ethyl ketone and tetrahydrofuran, the pigment is added to the organic solution using a stirring / dispersing device. And then phase-emulsifying using an aqueous medium, and then the organic solvent is distilled off to prepare a pigment paste.

The kneader is not particularly limited, and examples thereof include a Henschel mixer, a pressure kneader, a Banbury mixer, and a planetary mixer.
Also, the stirring / dispersing device is not particularly limited, and examples thereof include an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a dyno mill, a disperse mat, an SC mill, and a nanomizer. One of these may be used alone, or two or more devices may be used in combination.

  The amount of pigment in the pigment paste is preferably 5 to 60% by mass, and more preferably 10 to 50% by mass. When the pigment amount is less than 5% by mass, the water-based ink prepared from the pigment paste is insufficiently colored, and a sufficient image density tends not to be obtained. On the other hand, when the amount is more than 60% by mass, the dispersion stability of the pigment tends to decrease in the pigment paste.

  Further, since coarse particles cause nozzle clogging and other image characteristics to deteriorate, it is preferable to remove coarse particles by centrifugation or filtration before and after ink preparation.

  After the dispersion step, an impurity removal step by ion exchange treatment or ultrafiltration treatment may be performed, followed by post treatment. 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 to the organic pigment, mixed foreign matter, 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.

  After preparing the pigment paste, it is appropriately diluted and an additive as required is added to obtain an aqueous pigment dispersion according to the purpose. The form of the aqueous pigment dispersion is arbitrarily selected according to a preferred treatment method such as dip dyeing or printing according to the fiber to be colored. For example, in screen recording inks suitable for textile printing, additives include binder resins, preservatives, viscosity modifiers, pH adjusters, chelating agents, antioxidants, ultraviolet absorbers, flame retardants, and crosslinking agents. Etc., and the final pigment concentration is preferably in the range of 1 to 10% by mass.

  In addition, for example, when the application is an aqueous pigment dispersion for dip dyeing, additives include a binder resin, an antiseptic, a viscosity modifier, a pH adjuster, a chelating agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a crosslinking The final pigment concentration is preferably in the range of 1 to 10% by mass. The viscosity is arbitrarily set in accordance with the apparatus in the range of 1 mPa · s to 100 mPa · s. In addition, for example, the application uses a binder resin, a viscosity modifier, a pH adjuster, a chelating agent, a plasticizer, an antioxidant, an ultraviolet absorber, etc. as an additive in an aqueous pigment dispersion for spray printing, The final pigment concentration is preferably in the range of 1-10% by weight. The viscosity is arbitrarily set in accordance with the apparatus in the range of 1 mPa · s to 100 mPa · s.

  Further, for example, in an inkjet recording ink suitable for textile printing, as additives, binder resins, preservatives, viscosity modifiers, pH adjusters, chelating agents, antioxidants, ultraviolet absorbers, flame retardants, The final pigment concentration using a crosslinking agent or the like is preferably 1 to 20% by mass in order to ensure the necessity of obtaining a sufficient image density and the dispersion stability of the pigment in the ink. The dilution rate can be adjusted for ink jet recording ink by taking into account the concentration of the surfactant aqueous solution, diluting to the required concentration, and then performing ultrasonic treatment.

  Specific examples of the binder resin include styrene resin, acrylic resin, polyester resin, polyurethane resin (including the above-described polyurethane resin), and the like. The urethane resin is generally used in the range of 0.3% by mass to 12% by mass with respect to the total amount of the dispersion and ink. 0.6 mass%-9 mass% are preferable, Furthermore, 1.0 mass%-6 mass% are the most preferable.

The ratio of the binder resin to the pigment may be a ratio in a range usually used for a screen recording ink or an ink jet recording ink. For example, a ratio of the binder resin to the pigment = 1: 3 to 8: 1 is preferable.
The fastness depends on the molecular weight of the binder resin used, and the higher the molecular weight, the higher the fastness. In addition to this, the amount of binder used also contributes to the fastness. Therefore, in order to obtain higher fastness, it is preferable that the amount of the binder used is larger. In the urethane resin of the present invention, for example, 1: 1 to 8: 1 gives higher fastness. However, excessive use of a high molecular weight binder resin leads to an increase in viscosity. Therefore, when applied to ink for ink jet recording, it is preferable to determine the amount of binder used in consideration of the balance with viscosity.

  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 viscosity modifier include mainly water-soluble natural or synthetic polymers such as carboxymethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, gum arabic, and starch.

  Specific examples of the pH adjuster include collidine, imidazole, phosphoric acid, 3- (N-morpholino) propanesulfonic acid, tris (hydroxymethyl) aminomethane, boric acid and the like.

  Specific examples of chelating agents include ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, nitrilotriacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, N-hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, uramildiacetic acid, Examples include 1,2-diaminocyclohexane-N, N, N ′, N′-tetraacetic acid, malonic acid, succinic acid, glutaric acid, maleic acid and salts thereof (including hydrates).

  Specific examples of antioxidants or ultraviolet absorbers 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 Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor 252, 153, Irganox 1010, 1076, 1035, MD1024, or the like, or a lanthanide oxide or the like.

  The method for adding the diluent and additives can be carried out by a generally used method without any particular limitation. For example, the pigment paste is mixed with a binder resin, a surfactant, a viscosity modifier, an antifoaming agent, an antioxidant or an ultraviolet absorber, an antiseptic, and the like as additives. Examples thereof include a method of dispersing and mixing using a machine or a stirrer such as a bead mill, a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, an ultrahigh pressure homogenizer, or a pearl mill. If necessary, various additives may be further added thereafter.

  In addition, a water-soluble organic solvent may be further added for the purpose of stably dissolving or dispersing the additive and the pigment or the urethane resin.

  Examples of the water-soluble solvent include mono- or polyhydric alcohols, amides, ketones, ketoalcohols, cyclic ethers, glycols, polyhydric alcohol lower alkyl ethers, polyalkylene glycols, and glycerin. N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 1,2-pentanediol, 4-methyl-1,2- Pentanediol, 1,2 Polyols such as 6-hexanetriol, trimethylolpropane, pentaerythritol, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene Polyhydric alcohol alkyl ethers such as glycol monobutyl ether, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, and polyhydric alcohol aralkyl ethers, 2-pyrrolidone, N-methyl-2-pyrrolidone , Ε-caprolactam and other lactams, 1,3-dimethyli Midazolidinone acetone, ethyl acetate, N-methyl-2-pyrrolidone, m-butyrolactone, polyoxyalkylene adduct of glycerin, methyl acetate, tetrahydrofuran, 1,4-dioxane, dioxolane, propylene glycol monomethyl ether acetate, dimethyl sulfoxide, di Acetone alcohol, dimethylformamide propylene glycol monomethyl ether, and the like. These may be used alone or in combination of two or more.

  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.

  Further, the aqueous pigment dispersion of the present invention may contain a surfactant in order to control its permeability. The surfactant used at that time is preferably compatible with the other components present in the aqueous pigment dispersion of the present invention. Further, a surfactant having high penetrability and stability is preferable.

Specifically, it is preferable to use amphoteric surfactants and nonionic surfactants.
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 less foaming properties and have 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 wt% or more and 10 wt% or less with respect to the total amount of the aqueous pigment dispersion, and a more preferable upper limit value is 5.0 wt%, and a preferable lower limit value. The value is 0.5% by weight.

  Furthermore, when the aqueous pigment dispersion of the present invention is applied to the ink jet recording method, it is preferable to adjust the surface tension to 20 mN / m or more and 60 mN / m or less. More preferably, it is 20 mN / m or more and 45 mN / m or less, More preferably, it is 20 mN / m or more and 40 mN / m or less. If the surface tension is less than 20 mN / m, the liquid may overflow on the nozzle surface and printing may not be performed normally. On the other hand, when it exceeds 60 mN / m, there is a tendency that the non-absorbing base material is easily repelled. The viscosity is preferably 1.2 mPa · s or more and 20.0 mPa · s or less, more preferably 2.0 mPa · s or more and less than 15.0 mPa · s, and further preferably 3.0 mPa · s or more and 12 or more. Less than 0.0 mPa · s. When the viscosity is within this range, it is possible to achieve excellent dischargeability and good jetability over a long period of time. The surface tension can be appropriately adjusted by the surfactant.

(Adherent)
When the aqueous pigment dispersion obtained by the production method of the present invention is used as various inks, it can be printed not only on general-purpose adherends such as paper but also on fabric, artificial leather, natural leather and the like. Particularly excellent for printing on fabrics.
The fabric used in the present invention is preferably a medium composed of fibers, and may be a non-woven fabric or a non-woven fabric. As the material, a cloth made of any natural or synthetic fiber such as cotton, silk, wool, hemp, nylon, polyester, polyurethane, or rayon can be used.

  Hereinafter, although the effect of the present invention is concretely explained using an example and a comparative example, the present invention is not limited to these examples. In the following description, parts and% indicate parts by mass.

<Preparation of polyester polyol>
(Synthesis Example 1)
While introducing nitrogen gas in a reactor equipped with a thermometer, a nitrogen gas introduction tube, and a stirrer, 69.7 parts by mass of adipic acid, 49.8 parts by mass of butanediol and 0.05 part by mass of dibutyltin oxide were charged 180. After esterification at ˜230 ° C. for 24 hours, a polycondensation reaction is performed at 230 ° C. for 24 hours until the acid value becomes 1 or less. Group cyclic concentration 0 mol / Kg].

In addition, the said acid value is the value produced by titrating according to the potassium hydroxide method, and a hydroxyl value is the value measured by the method based on JISK1557-1 description.

(Synthesis Example 2)
While introducing nitrogen gas in a reactor equipped with a thermometer, nitrogen gas inlet tube, and stirrer, 42.1 parts by mass of isophthalic acid, 21.4 parts by mass of sebacic acid, 9.3 parts by mass of adipic acid, ethylene glycol 7 7 parts by mass, 25.8 parts by mass of neopentyl glycol, 11.2 parts by mass of butanediol, and 0.05 parts by mass of dibutyltin oxide were esterified at 180 to 230 ° C. for 24 hours, and the acid value was reduced to 1 or less. A polycondensation reaction was carried out at 230 ° C. for 24 hours until an aromatic polyester polyol (2) (acid value 0.3, hydroxyl value 56.1, aromatic cyclic concentration 2.53 mol / kg) was obtained.

(Synthesis Example 3)
While introducing nitrogen gas in a reaction vessel equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 33.0 parts of isophthalic acid, 33.0 parts of terephthalic acid, 23.5 parts of butanediol, 27.2 of neopentyl glycol Parts and dibutyltin oxide 0.04 part, and a polycondensation reaction is carried out at 230 ° C. for 24 hours until the acid value becomes 1 or less at 180 to 230 ° C., and aromatic polyester polyol (1) [acid value 0.2, hydroxyl group Value 112.2, aromatic cyclic concentration 3.98 mol / Kg].

Abbreviations in Table 1 will be described below.
PES-1: Polyester polyol obtained in Synthesis Example 1 PES-2: Polyester polyol obtained in Synthesis Example 2 PES-3: Polyester polyol obtained in Synthesis Example 3 * 1: Included in synthesized PES-1 to PES-3 Aromatic cyclic concentration.

<Synthesis of urethane resin>
(Production Example 1)
In a reaction vessel, 100 parts by mass of the aliphatic polyester polyol (1) obtained in Synthesis Example 1 was dehydrated at 100 ° C. under reduced pressure, and after cooling to 80 ° C., 94.1 parts by mass of methyl ethyl ketone was added, stirred and mixed uniformly. did. Next, 8.8 parts by mass of 2,2-dimethylolpropionic acid and 4.2 parts by mass of 1,4-butanediol were added, and then 28.1 parts by mass of tolylene diisocyanate and 0.08 parts by mass of dibutyltin dilaurate were added. In addition, the reaction was carried out at 80 ° C. for 12 hours to carry out the urethanization step. It was confirmed that the isocyanate value was 0.1% or less, 0.4 parts by weight of normal butanol was added, and the mixture was further reacted for 2 hours, then cooled to 50 ° C., and the nonvolatile content of the urethane resin having a hydrophilic group A 60% by weight solution was obtained.
Then, it is cooled to 50 ° C., 6.7 parts by mass of triethylamine and 710 parts by mass of water are added, methyl ethyl ketone is removed under reduced pressure at a temperature of 40 ° C. to 60 ° C., and water is added to adjust the concentration. A resin composition having a nonvolatile content of 23% by mass in which the urethane resin was dispersed in an aqueous medium was obtained.

(Production Example 2)
In a reaction vessel, 100 parts by mass of the aromatic polyester polyol (2) obtained in Synthesis Example 2 was dehydrated at 100 ° C. under reduced pressure, and after cooling to 80 ° C., 94.1 parts by mass of methyl ethyl ketone was added, stirred and mixed uniformly. did. Next, 8.8 parts by mass of 2,2-dimethylolpropionic acid and 4.2 parts by mass of 1,4-butanediol were added, and then 28.1 parts by mass of tolylene diisocyanate and 0.08 parts by mass of dibutyltin dilaurate were added. In addition, the reaction was carried out at 80 ° C. for 12 hours to carry out the urethanization step. It was confirmed that the isocyanate value was 0.1% or less, 0.4 parts by weight of normal butanol was added, and the mixture was further reacted for 2 hours, then cooled to 50 ° C., and the nonvolatile content of the urethane resin having a hydrophilic group A 60% by weight solution was obtained.
Then, it is cooled to 50 ° C., 6.7 parts by mass of triethylamine and 710 parts by mass of water are added, methyl ethyl ketone is removed under reduced pressure at a temperature of 40 ° C. to 60 ° C., and water is added to adjust the concentration. A resin composition having a nonvolatile content of 23% by mass in which the urethane resin was dispersed in an aqueous medium was obtained.

(Production Example 3)
In a reaction vessel, 100 parts by mass of the aromatic polyester polyol (3) obtained in Synthesis Example 3 was dehydrated at 100 ° C. under reduced pressure, and after cooling to 80 ° C., 91.0 parts by mass of methyl ethyl ketone was added, stirred and mixed uniformly. did. Next, 8.1 parts by mass of 2,2-dimethylolpropionic acid was added, then 28.4 parts by mass of tolylene diisocyanate and 0.08 parts by mass of dibutyltin dilaurate were added and reacted at 80 ° C. for 12 hours. The process was carried out. It was confirmed that the isocyanate value was 0.1% or less, 0.4 parts by weight of normal butanol was added, and the mixture was further reacted for 2 hours, then cooled to 50 ° C., and the nonvolatile content of the urethane resin having a hydrophilic group A 60% by weight solution was obtained.
Then, it cools to 50 degreeC, 4.1 mass part and 25 mass parts of 25% ammonia aqueous solution are added, methyl ethyl ketone is removed under the temperature of 40 to 60 degreeC under pressure reduction, 710 mass parts of water is added, and a density | concentration is added. By performing the adjustment, a resin composition having a nonvolatile content of 23% by mass in which the urethane resin was dispersed in an aqueous medium was obtained.

(Production Example 4)
50 parts by weight of the aliphatic polyester polyol (1) obtained in Synthesis Example 1 and 50 parts by weight of the aromatic polyester polyol (2) obtained in Synthesis Example 2 in a reaction container were dehydrated at 100 ° C. under reduced pressure, Thereafter, after cooling to 80 ° C., 94.1 parts by mass of methyl ethyl ketone was added and stirred and mixed uniformly. Next, 8.8 parts by mass of 2,2-dimethylolpropionic acid and 4.2 parts by mass of 1,4-butanediol were added, and then 28.1 parts by mass of tolylene diisocyanate and 0.08 parts by mass of dibutyltin dilaurate were added. In addition, the reaction was carried out at 80 ° C. for 12 hours to carry out the urethanization step. It was confirmed that the isocyanate value was 0.1% or less, 0.4 parts by weight of normal butanol was added, and the mixture was further reacted for 2 hours, then cooled to 50 ° C., and the nonvolatile content of the urethane resin having a hydrophilic group A 60% by weight solution was obtained.
Then, it is cooled to 50 ° C., 6.7 parts by mass of triethylamine and 710 parts by mass of water are added, methyl ethyl ketone is removed under reduced pressure at a temperature of 40 ° C. to 60 ° C., and water is added to adjust the concentration. A resin composition having a nonvolatile content of 23% by mass in which the urethane resin was dispersed in an aqueous medium was obtained.

(Production Example 5)
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen blowing tube, 100 parts by mass of polyoxytetramethylene glycol (weight average molecular weight: 2,000) under a nitrogen stream, 2.2′-di After adding 8.8 parts by weight of methylolpropionic acid and 4.2 parts by weight of 1,4-butanediol and mixing uniformly, 28.1 parts by weight of tolylene diisocyanate is added, and then 0.1 part by weight of dibutyltin dilaurate is added. In addition, the reaction was carried out at 80 ° C. for about 12 hours to carry out the urethanization step. It was confirmed that the isocyanate value was 0.1% or less, 0.4 parts by weight of normal butanol was added, and the mixture was further reacted for 2 hours, then cooled to 50 ° C., and the nonvolatile content of the urethane resin having a hydrophilic group A 60% by weight solution was obtained.
Then, it is cooled to 50 ° C., 6.7 parts by mass of triethylamine and 710 parts by mass of water are added, methyl ethyl ketone is removed under reduced pressure at a temperature of 40 ° C. to 60 ° C., and water is added to adjust the concentration. A resin composition having a nonvolatile content of 23% by mass in which the urethane resin was dispersed in an aqueous medium was obtained.

Abbreviations in Table 2 will be described below.
PUD-1: Urethane resin PUD-2 obtained in Production Example 1: Urethane resin PUD-3 obtained in Production Example 2: Urethane resin PUD-4 obtained in Production Example 3: Urethane resin PUD- obtained in Production Example 4 5: Urethane resin obtained in Production Example 5 * 2: Aromatic cyclic concentration contained in the total amount of polyester polyol used.

<Preparation of Example 1 high concentration aqueous pigment dispersion>
Urethane resin PUD-1 19.6 parts, copper phthalocyanine pigment (PB15: 3, product name FASTOGEN BLUE 5327 WET manufactured by DIC) 15 parts (solid content conversion) and water 65.4 parts are mixed and stirred, and this mixture is mixed. After adding 500 parts of 0.3 mmφ ceramic beads, it was ground with a 6-cylinder sand grinder for 6 hours. After grinding, the ceramic beads were separated to obtain a mill base. The mill base obtained above was subdivided for 3 hours using an ultrasonic homogenizer at an output of 600 W to obtain a high concentration aqueous pigment dispersion. The composition of each high-concentration aqueous pigment dispersion is shown in the attached table.

<Example 2 Preparation of high concentration aqueous pigment dispersion>
A high concentration aqueous pigment dispersion was obtained in the same manner as in Example 1 except that 19.6 parts of PUD-2 was used instead of the urethane resin PUD-1.

Example 3 Preparation of High Concentration Aqueous Pigment Dispersion
A high concentration aqueous pigment dispersion was obtained in the same manner as in Example 1 except that 19.6 parts of PUD-3 was used instead of the urethane resin PUD-1.

<Example 4 Preparation of high-concentration aqueous pigment dispersion>
A high concentration aqueous pigment dispersion was obtained in the same manner as in Example 1 except that 19.6 parts of PUD-4 was used instead of the urethane resin PUD-1.

<Comparative Example 1 Preparation of High Concentration Aqueous Pigment Dispersion>
A high concentration aqueous pigment dispersion was obtained in the same manner as in Example 1 except that 19.6 parts of PUD-5 was used instead of the urethane resin PUD-1.

<Evaluation of initial dispersibility>
The obtained high-concentration aqueous pigment dispersion was measured with a Microtrac UPA ("UPA-EX150" manufactured by Nikkiso Co., Ltd.), and D50 (50% of the particles were less than the particle size) in the particle size distribution. Evaluation).
Less than 150nm → ○
150-200nm → △
> 200nm → ×

<Evaluation of storage stability>
20 ml of the high-concentration aqueous pigment dispersion obtained in Examples 1 to 4 and Comparative Example 1 was sealed in a glass container and allowed to stand at 50 ° C. for 1 week, and then evaluated as follows.
Change rate from initial viscosity ± 5% or less → ○
Change rate from initial viscosity ± 5 to less than 10% → △
Change rate from initial viscosity ± 10% or more → ×

Abbreviations in Table 3 will be described below.
PUD-1: Urethane resin PUD-2 obtained in Production Example 1: Urethane resin PUD-3 obtained in Production Example 2: Urethane resin PUD-4 obtained in Production Example 3: Urethane resin PUD- obtained in Production Example 4 5: Urethane resin obtained in Production Example 5

<Example 5 Preparation of aqueous pigment dispersion>
30 parts of the high-concentration aqueous pigment dispersion obtained in Example 1 and 8 parts of a solvent (water, water-soluble solvent, oil-soluble solvent, etc.) and an aqueous urethane resin (Hydran WLS213 manufactured by DIC Corporation) as a binder resin. The aqueous pigment dispersion of Example 5 was obtained by addition. The composition of each aqueous pigment dispersion is shown in the attached table. At the time of addition in each example, the mixture was sufficiently stirred with a dispersion stirrer (TK Homo Disper L manufactured by Tokushu Kika Kogyo Co., Ltd.).

<Example 6 Preparation of aqueous pigment dispersion>
In the same manner as in Example 5, except that 30 parts of the high concentration aqueous pigment dispersion obtained in Example 2 was used instead of the high concentration aqueous pigment dispersion obtained in Example 1, the aqueous A pigment dispersion was obtained.

<Example 7 Preparation of aqueous pigment dispersion>
In the same manner as in Example 5, except that 30 parts of the high concentration aqueous pigment dispersion obtained in Example 3 was used instead of the high concentration aqueous pigment dispersion obtained in Example 1, the aqueous A pigment dispersion was obtained.
<Example 8 Preparation of aqueous pigment dispersion>
In the same manner as in Example 5, except that 30 parts of the high concentration aqueous pigment dispersion obtained in Example 4 was used instead of the high concentration aqueous pigment dispersion obtained in Example 1, the aqueous A pigment dispersion was obtained.

<Comparative Example 2 Preparation of aqueous pigment dispersion>
In the same manner as in Example 5, except that 30 parts of the high concentration aqueous pigment dispersion obtained in Comparative Example 1 was used instead of the high concentration aqueous pigment dispersion obtained in Example 1, the aqueous A pigment dispersion was obtained.

<Production of evaluation fabric>
Using the aqueous pigment dispersions obtained in the above Examples and Comparative Examples, printing was performed on the surface of the fabric by the following method to obtain various evaluation fabrics.

<Fabrication for fastness evaluation_Screen printing>
Printing evaluation was performed by a screen printing method using an auto screen printing machine (manufactured by Sakurai Dyeing Machine Co., Ltd.). Each ink was printed on a polyester / cotton fabric on a 135 mesh striped screen, dried at 120 ° C. for 2 minutes, and then subjected to heat treatment at 150 ° C. for 2 minutes. As a result of visual inspection of the printed material, all the products were of good quality.

<Production of Evaluation Fabric_Inkjet Printing>
The ink cartridge of an inkjet printer (Seiko Epson Co., Ltd., MJ-510C) was filled and printed. Each ink was printed on a polyester / cotton fabric, dried at 120 ° C. for 2 minutes, and heat-treated at 150 ° C. for 2 minutes. As a result of visual inspection of the printed material, all the products were of good quality.

<Washing fastness evaluation method>
For printed matter obtained by screen printing, the test was repeated 30 times in accordance with the A-4 method of JIS L 0844: 2005, and then the visual method using the gray scale for fading color of JIS L 0801: 2004 The grades were judged from grades 1 to 5 in accordance with the judgment criteria of No. 1. In addition, as for the grade, 1st grade has the largest fading, and the closer to 5th grade, the less fading.

<Friction fastness evaluation method>
A printed material obtained by screen printing is subjected to a dry type and a wet type test using a Gakushin type friction fastness tester according to JIS L 0849: 2004, and then a change of JIS L 0801: 2004 is performed. The grades were judged from 1st to 5th grades according to the criteria of visual sense using the gray scale for fading. In addition, as for the grade, 1st grade has the largest fading, and the closer to 5th grade, the less fading.

  Table 4 shows the compositions and various evaluation results of the aqueous pigment dispersions of Examples and Comparative Examples. The unit of blending in the table is part.

Abbreviations in Table 4 will be described below.
PUD-1: Urethane resin PUD-2 obtained in Production Example 1: Urethane resin PUD-3 obtained in Production Example 2: Urethane resin PUD-4 obtained in Production Example 3: Urethane resin PUD- obtained in Production Example 4 5: Urethane resin obtained in Production Example 5

  From the results of Table 4, the high concentration aqueous pigment dispersion using the urethane resin (A) having a polyester structure according to the present invention (Examples 1 to 4) showed good initial dispersibility and storage stability. Moreover, the fabric using the aqueous pigment dispersion using the urethane resin (A) having a polyester structure according to the present invention (Examples 5 to 8) has good washing fastness and friction fastness (dry type, wet type). )showed that. On the other hand, in the comparative example using a urethane resin having no polyester structure, the initial dispersibility and storage stability of the high concentration aqueous pigment dispersion were good, but both the fastness to washing and the fastness to friction were inferior. It was.

Claims (6)

A polyester polyol (a1-1) obtained by reacting a polycarboxylic acid and a polyol as the polyol (a1), and a hydrophilic property which is an anionic group, a cationic group, a polyoxyethylene group or a polyoxyethylene-polyoxypropylene group A pigment dispersant using a urethane resin obtained by reacting a polyol having a group with a polyisocyanate (a2). The pigment dispersant according to claim 1, wherein the polycarboxylic acid of the polyester polyol (a1-1) contains an aromatic polycarboxylic acid. The pigment dispersant according to claim 1 or 2, wherein the aromatic cyclic concentration contained in the total amount of the polyester polyol (a1-1) is 2.5 mol / kg or more. A method for producing an aqueous pigment dispersion, comprising dispersing a pigment in a water-soluble solvent and / or water using the pigment dispersant according to claim 1. A textile printing method, wherein the aqueous pigment dispersion obtained by the production method according to claim 4 is printed on a fabric. An ink-jet printing method comprising printing a water-based pigment dispersion obtained by the production method according to claim 4 on a fabric.