JP6172661B2 - Polyurethane resin adhesion pigment, pigment dispersion composition, and ink jet ink composition - Google Patents

Description

  The present invention relates to a polyurethane resin-attached pigment, a pigment dispersion composition, and an inkjet ink composition.

In recent years, water-based inks have been widely used to replace organic solvent-based inks in a wide range of fields because of their safety and low environmental impact. Especially for business applications, water-free color materials that are odorless are essential as inks used for various printing in offices. For industrial applications, organic solvents can be used due to problems in the working environment, safety of ink and paint handling, and waste liquid treatment. There is an increasing tendency to reduce usage as much as possible.
In addition, water-based colorants are also more popular than organic solvent-type colorants because they do not require special equipment such as explosion-proof equipment, exhaust equipment, and organic solvent recovery equipment during production. .

  As water-based colorants, two types of dyes and pigments are used depending on the application. Dyes are excellent in gradation and easy to form high-resolution images, but they have poor light resistance compared to pigments and have practical problems. There is. In contrast, pigments are inferior in dispersibility to dyes, but are extremely excellent in water resistance and light resistance, and many pigment inks have been provided by the advancement of dispersion technology.

  Gravure inks that are printed via printing plate making and water-based liquid inks for offset printing have been developed, but the most popular recording method for offices that uses water-based inks is the ink jet recording method.

  The ink jet recording method is a method in which ink droplets are ejected from a fine nozzle head and characters and images are recorded on the surface of a recording medium such as paper. Since it can be easily printed on demand without making a full color printing plate on a simple recording medium, it has begun to spread widely.

  An ink jet printer that employs an ink jet recording method is a method in which ink droplets are ejected from a fine nozzle head and characters and images are recorded on the surface of a recording medium such as paper. (Registered trademark) method and piezo method. The former is a recording method that instantaneously heats the ink guided to the nozzle head with a heater to generate bubbles, and the ink expansion is intermittently ejected by volume expansion due to the bubbles, the latter is an electrostrictive element (piezoelectric element) Is a recording method in which an electrical signal is converted into a mechanical signal using ink and ink droplets stored in a nozzle head portion are ejected intermittently.

  Among ink compositions for inkjet printers (inkjet ink compositions), black ink compositions are widely used in offices and the like mainly for the purpose of document printing, and are water-based optimized for the recording method and recording speed of each printer. Many black pigment ink compositions are provided.

  For example, an aqueous black pigment ink composition in which the surface of a black pigment is hydrophilized to improve dispersibility in an aqueous medium has been proposed (see, for example, Patent Document 1). When the ink is printed on the paper, the ink composition penetrates into the paper, which causes problems such as a decrease in image density, an offset, and curling of the recording paper. In particular, with the recent increase in printing speed of ink jet printers, the amount of ink discharged per unit time tends to increase, so that conventional aqueous black pigments may not provide sufficient image density.

  In addition, since pigments have a weak affinity with other substances such as organic polymers, water, and organic solvents compared to the cohesion between particles, they are uniformly mixed or dispersed under normal mixing or dispersion conditions. It is extremely difficult to adsorb a dispersant made of various surfactants, resins, etc. on the pigment surface, and the entire pigment surface is coated with the dispersant, so that it can be mixed with other solid or liquid components. Many studies have been made to improve the dispersibility of the pigment by increasing the affinity (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 08-003498 Japanese Patent Application Laid-Open No. 08-2158015

  However, as a result of diligent investigations by the present inventors, in a conventional aqueous pigment ink composition in which a dispersant is adsorbed on the pigment surface, the ink composition is ejected from a thin nozzle provided in the nozzle head. It has been found that the dispersion state of the pigment becomes unstable due to the release of the dispersant due to the application of a strong shearing force or the release of the dispersant during long-term storage, leading to deterioration in storage stability. When an aqueous dispersion resin such as an acrylic emulsion is added to improve the scratch resistance and marker resistance of the ink coating film, storage stability and ejection stability are lowered. In addition, when the entire pigment is coated with a dispersant and microencapsulated, the storage stability is excellent, but the image density is greatly reduced.

  In addition, it is known that a colorant that lowers the functional group concentration on the pigment surface and does not penetrate into the printed material such as paper and remains on the surface has a higher image density. It will reduce the solubility and scratch resistance.

  Accordingly, the present invention provides a polyurethane resin that, when used in a pigment dispersion composition, exhibits excellent image density, dispersibility and storage stability, and can form an ink coating film with excellent marker resistance and scratch resistance. An object of the present invention is to provide a pigment dispersion composition and an ink-jet ink composition as well as an adhesion pigment.

  In order to achieve the above object, the present inventors have intensively studied and found that the polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group has a primary group having a hydroxyl group. A water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a hydroxyl group at the end, which is brought into contact with an amine or a secondary amine (II), and a pigment (IV) having an acidic group on the surface The present inventors have found that the above technical problem can be solved by a polyurethane resin adhesion pigment that is brought into contact with an aqueous medium, and have completed the present invention based on this finding.

That is, the present invention
(1) A polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group is contacted with a primary amine or secondary amine (II) having a hydroxyl group. A polyurethane resin comprising a water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a hydroxyl group at a terminal and a pigment (IV) having an acidic group on the surface in an aqueous medium. Adhesion pigment,
(2) The polyurethane resin-attached pigment according to (1), wherein the pigment (IV) having an acidic group on the surface is a self-dispersing pigment having an acidic group on the surface,
(3) The polyurethane resin-attached pigment according to (1), wherein the pigment (IV) having an acidic group on the surface is a self-dispersing carbon black having an acidic group on the surface,
(4) A pigment dispersion composition comprising the polyurethane resin-attached pigment according to (1) to (3) above,
(5) An inkjet ink composition comprising a polyurethane resin-attached pigment as described in (1) to (3) above,
(Hereinafter, the polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group is referred to as “polyisocyanate polyurethane resin (I)”, and has a urea bond in the molecule. (The water-dispersible polyurethane resin (III) having a hydroxyl group at the terminal is referred to as “water-dispersible polyurethane resin (III)”, respectively.)

According to the present invention, a primary amine or secondary amine (II) having a hydroxyl group is brought into contact with the polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group. The water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a terminal hydroxyl group and a pigment (IV) having an acidic group on the surface are brought into contact with each other in an aqueous medium. The low polarity main chain of the polyurethane resin (III) is physically adsorbed on the pigment (IV) having an acidic group on the surface, and the hydroxyl group, anionic polar group or nonionic polarity of the water dispersible polyurethane resin (III). The chain exhibits affinity for aqueous media, and the water-dispersible polyurethane resin (III) functions as a kind of pigment dispersant. The urea bond formed by bringing the primary or secondary amine (II) into contact with the terminal isocyanate group of the letane resin (I) can form a tough ink coating film when used in a pigment dispersion composition. A polyurethane resin-attached pigment that can exhibit excellent image density, dispersibility, and storage stability when used in a pigment dispersion composition, and can form an ink coating with excellent marker resistance and scratch resistance. Can be provided.
Further, according to the present invention, a pigment dispersion composition and an inkjet ink composition which are excellent in image density, dispersibility, storage stability, marker resistance and scratch resistance of an ink coating film by including the above polyurethane resin adhesion pigment. Can be provided.

First, the polyurethane resin adhesion pigment of this invention is demonstrated.
The polyurethane resin-attached pigment of the present invention comprises a primary amine or a secondary amine (II) having a hydroxyl group on a polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group. A water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a terminal hydroxyl group, and a pigment (IV) having an acidic group on the surface, in an aqueous medium. It is characterized by.

The polyisocyanate polyurethane resin (I) has an anionic polar group or a nonionic polar chain, and the polyisocyanate polyurethane resin (I) has an anionic polar group, a nonionic polar chain, Examples thereof include those having both an anionic polar group and a nonionic polar chain.
In the polyisocyanate polyurethane resin (I), examples of the anionic polar group include a carboxyl group, and the nonionic polar chain includes a polyoxyethylene ether chain or a polyoxyethylene ether chain-containing polyoxyethylene ether chain. An alkylene ether chain etc. can be mentioned.

  The water-dispersible polyurethane resin (I) having an anionic polar group or a nonionic polar chain has an anionic polar group or a nonionic polar chain dispersible in an aqueous medium in the molecule, and has two or more hydroxyl groups. It can be obtained by urethane bonding an excess molar amount of the polyisocyanate compound relative to the molar amount of the polyol compound.

  As a polyol compound having an anionic polar group or nonionic polar chain dispersible in an aqueous medium in the molecule and having two or more hydroxyl groups, the water-dispersible polyurethane resin (III) is added in the aqueous medium in the final stage. Those having a functional group capable of forming a salt to be phase-inverted are preferred, and specific examples thereof include tertiary carboxyl group-containing polyol compounds.

  Examples of the tertiary carboxyl group-containing polyol compound include polyhydroxycarboxylic acids such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolacetic acid, dimethylolbutyric acid, dimethylolvaleric acid, and dimethylolcaproic acid. Of these, dihydroxymonocarboxylic acids such as dimethylolpropionic acid and dimethylolbutanoic acid are preferred. Since the tertiary carboxyl group of the polyol compound has extremely low reactivity with the isocyanate compound, the target polyurethane resin can be efficiently produced without inhibiting the urethane bond reaction.

  Further, by controlling the blending amount of the tertiary carboxyl group-containing polyol compound, it becomes possible to control the acid value of the resulting water-dispersible polyurethane resin (III). In addition to the secondary carboxyl group-containing polyol compound, a diol compound further having a nonionic molecular chain can be used.

  Examples of the diol compound having a nonionic molecular chain include polyethylene glycol diol (PEG) or a copolymer diol of polyethylene glycol diol (PEG) and polypropylene glycol diol (PPG) or polybutylene glycol diol (PBG). And polyalkylene glycol diols.

  Along with the tertiary carboxyl group-containing polyol compound and the diol compound having a nonionic molecular chain, a polyol having at least two hydroxyl groups in the molecule can be used in an arbitrary ratio.

  Examples of the polyol having at least two hydroxyl groups in the molecule include side chain modified diols and the like that have been chemically modified according to the purpose by a reaction such as Michael addition, and various hydrophobic groups and hydrophilic groups in the side chain. Introducing can make a wide range of balance between hydrophilicity and hydrophobicity in the obtained water-dispersible polyurethane resin (III).

  The side chain-modified diol can be synthesized by an addition reaction between a dialkanolamine and a (meth) acrylic acid derivative. The reaction such as Michael addition is preferable because the addition reaction with a highly reactive acrylic acid derivative is easier to control than the reaction between a dialkanolamine and a methacrylic acid derivative.

Although it does not specifically limit as dialkanolamine, Dihydroxyalkyl substitution products of secondary amines, such as diethanolamine, dipropanolamine, and diisopropanolamine, can be mentioned.
The (meth) acrylic acid derivative is not particularly limited. For example, (meth) acrylic acid alkyl ester, (meth) acrylic acid cycloalkyl ester, (meth) acrylic acid substituted aromatic ester, (meth) acrylic acid halogenated Examples thereof include alkyl esters, (meth) acrylic acid esters, aromatic vinyl compounds, vinyl cyanide compounds, unsaturated dibasic acids or derivatives thereof.

  Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like.

  Examples of the (meth) acrylic acid cycloalkyl ester include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, and the like. It is done.

  Examples of the (meth) acrylic acid aromatic ester include phenyl (meth) acrylate, benzyl (meth) acrylate, and the like.

  Examples of the (meth) acrylic acid halogenated alkyl ester include fluoromethyl (meth) acrylate, fluoroethyl (meth) acrylate, and the like.

  Examples of the (meth) acrylic acid ester include (meth) acrylic acid hydroxyalkyl ester, (meth) acrylic acid glycidyl, (meth) acrylic acid ethylene glycol ester, (meth) acrylic acid polyethylene glycol ester, and the like.

  Examples of the aromatic vinyl compound include α-substituted styrene such as styrene, α-methylstyrene, and α-ethylstyrene, and nucleus-substituted styrene such as fluorostyrene and methylstyrene.

  Other (meth) acrylic acid derivatives include aliphatic monoacrylates such as 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate Monoacrylate having an alicyclic structure such as isobornyl (meth) acrylate; benzyl (meth) acrylate, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, phenoxytetraethylene glycol (meth) acrylate , Aromatic monoacrylates such as nonylphenoxyethyl (meth) acrylate and nonylphenoxytetraethylene glycol (meth) acrylate; Alkyl ether acrylates such as glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate; 2- (meth) acryloyloxy Dibasic acid mono (meth) acryloyloxy such as ethyl hydrogen succinate, 2- (meth) acryloyloxyethyl hydrogen hexahydrophthalate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen phthalate Esters: Mono 2-ethylhexyl ether polyoxyethylene glycol (meth) acrylate, monononyl phenyl ether Monoalkyl ether polyoxyalkylene glycol (meth) acrylates such as polyoxyethylene glycol (meth) acrylate, mono 2-ethylhexyl ether polyoxypropylene glycol (meth) acrylate, monononylphenyl ether polyoxypropylene glycol (meth) acrylate; polyethylene Monoacrylates having polyoxyethylene ether bonds such as glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate 2-hydroxy-3-butoxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate Mono (meth) acrylate having hydroxyl group such as ε-caprolactone adduct of 2-hydroxyethyl (meth) acrylate; alicyclic ether (meth) acrylate such as glycidyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate Nitrogen-containing N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, morpholino (meth) acrylate, N, N-dimethylacrylamide, dimethylaminopropyl acrylate, N-isopropylacrylamide, etc. Polyoxyalkylene phosphate mono (meth) acrylates such as monoacrylate, polyoxyethylene phosphate mono (meth) acrylate, polyoxypropylene phosphate mono (meth) acrylate And the like.

  As a raw material to be used for the Michael addition reaction for obtaining the side chain-modified diol, an acrylic acid derivative is preferable to a methacrylic acid derivative because it has a higher reactivity with an amine and a lower reaction temperature.

  Examples of polyols having at least two hydroxyl groups in the molecule include ethylene glycol, propylene glycol, cyclohexane-1,4-dimethanol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1 , 6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8 Examples include diols such as -octanediol, 1,9-nonanediol, cyclohexyldimethanol, and polymer polyols.

Examples of the polymer polyol include polyester polyols such as polyester diol, polymer diols such as polylactone diol, polycarbonate diol, and polybutadiene diol, and polyether polyols. In addition, a polymer diol of a compound having a rosin skeleton or a hydrogenated rosin skeleton can be given.
The molecular weight of the polymer polyol is preferably 300 to 5000 in terms of number average molecular weight, and more preferably 500 to 3000 in terms of number average molecular weight.

  The polyester polyol is obtained by a condensation reaction of one or more of the following polyols and polyol synergistic components with one or more of polybasic acids and their anhydrides. Things.

  Polyols that are raw materials for polyester polyols include ethylene glycol, propylene glycol, cyclohexane-1,4-dimethanol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 1, Examples thereof include 9-nonanediol, cyclohexanedimethanol, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, castor oil-modified diol, castor oil-modified polyol, and the like.

  Polyol synergists that are raw materials for polyester polyols include alkyl monoglycidyl ethers such as butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, decyl glycidyl ether and stearyl glycidyl ether, and alkyl glycidyl esters (product name Cardura). E10: manufactured by Shell Japan Co., Ltd.), or one or more of monoepoxy compounds.

  Polybasic acids that are raw materials for polyester polyols and their anhydrides include aliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dimer acid, and their anhydrides, dodecenyl succinic anhydride, anhydrous Aromatic polybasic acids such as phthalic acid, isophthalic acid, terephthalic acid and trimellitic anhydride, and their anhydrides, alicyclic polybasic acids such as hydrophthalic anhydride and dimethyl-1,4-cyclohexanedicarboxylic acid, and their An anhydride etc. are mentioned.

  As the polylactone diol, a polyester polyol obtained by ring-opening addition polymerization of a monomer having a lactone ring such as ε-caprolactone or β-methyl-δ-valerolactone, starting from a hydroxyl-terminated compound such as the above polyol or the above polyester polyol. Are also examples of polyester polyols.

  Examples of the polycarbonate diol include 1,4 butanediol, 1,6 hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, and 2-butyl-2-ethyl-1,3. -Polycarbonate diols using diols such as propanediol, 1,9-nonanediol and 2-methyl-1,8-octanediol as raw materials.

As polybutadiene diol, the following formula:

(However, k = 0.2, l = 0.2, m = 0.6, and n is a positive integer.) Polybutadienediol Poly bdR-15HT, R-45HT represented by Idemitsu Kosan Co., Ltd. And polyisoprene diol Poly ip (manufactured by Idemitsu Kosan Co., Ltd.).

In addition, as polybutadiene diol, the following formula

(In the formula, n represents a positive integer.)
Α, ω-polybutadiene glycol G-1000, G-2000, G-3000 (manufactured by Nippon Soda Co., Ltd.) and the like represented by

  Polyether polyols include polyethylene glycol diol (PEG), polypropylene glycol diol (PPG), polyalkylene glycols represented by polybutylene glycol diol (PBG), bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol. Starting from F or the like, polyether polyols to which propylene oxide, tetrahydrofuran, or butylene oxide is added may be mentioned.

  Examples of the polymer diol of the compound having a rosin skeleton or a hydrogenated rosin skeleton include Pine Crystal D-6011 and D-6240 (Arakawa Chemical Industries, Ltd.).

  On the other hand, the polyisocyanate compound is not particularly limited as long as it contains two or more isocyanate groups in the molecule. Depending on the purpose, one or more selected from diisocyanate compounds or polyisocyanate compounds containing three or more isocyanate groups can be used.

  Examples of the diisocyanate compound include diphenylmethane diisocyanate (hereinafter abbreviated as MDI), polyphenylene polymethylene polyisocyanate, tolylene diisocyanate (hereinafter abbreviated as TDI), xylylene diisocyanate, tetramethylxylylene diisocyanate, and isophorone diisocyanate (hereinafter abbreviated as IPDI). , Hexamethylene diisocyanate (hereinafter abbreviated as HDI), tetramethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, naphthalene diisocyanate, hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate 1,3-bis (isocyanatomethyl) -cyclohexane Hydrogenated XDI) and the like, and some of the isocyanate groups of these isocyanate group-containing compounds were modified into burette, allophanate, carbodiimide, uretonimine, oxazolidone, amide, imide, isocyanurate, uretdione, etc. Things. These may be used alone or in combination of two or more as required.

  Among these diisocyanate compounds, non-aromatic diisocyanate compounds having a slower reaction rate with water than aromatic diisocyanate compounds are preferred. In consideration of the reactivity with water, the terminal isocyanate group of the polyisocyanate polyurethane resin (I) having a terminal isocyanate group is preferably an alicyclic or aliphatic diisocyanate that reacts relatively slowly with water, and a molecular terminal isocyanate. It is also possible to introduce an aromatic diisocyanate compound into the molecule by making the group derived from an alicyclic or aliphatic diisocyanate.

  The polyisocyanate polyurethane resin (I) having a terminal isocyanate group is obtained by, for example, reacting an aromatic diisocyanate with an excess (molar ratio) diol in the first reaction stage, and then reacting an alicyclic or aliphatic diisocyanate. Can be produced. Since aromatic diisocyanates have higher reactivity with diols, the reaction temperature can be controlled using this difference in reactivity, and terminal isocyanate groups can be made from alicyclic or aliphatic diisocyanate-derived isocyanates. .

  In order to prepare a polyisocyanate polyurethane resin (I) having a terminal isocyanate group by urethane-bonding a polyol compound having at least two hydroxyl groups in the molecule and a diisocyanate compound, at least two hydroxyl groups are added in the molecule. The compounding ratio in which the number of equivalents of the isocyanate group of the diisocyanate compound is 2 equivalents or more relative to the number of equivalents of the hydroxyl group in the compound having a compound (when a diol compound is used as the compound having at least two hydroxyl groups in the molecule, By setting the blending ratio to be 1 mol greater, a polyurethane resin having isocyanate groups at both ends can be obtained. A method of increasing the molecular weight by synthesizing isocyanate-terminated oligomers in multiple stages is also useful because an isocyanate-terminated polymer can be obtained with high accuracy and a polyurethane resin with little variation in molecular weight distribution can be obtained.

  In order to obtain the polyurethane resin, taking a reaction of a compound having two hydroxyl groups in the molecule (diol) and a diisocyanate compound as an example, in an organic solvent, when the total number of moles of the diol is n, A polyurethane having a terminal isocyanate group can be synthesized by reacting so that the total number of moles of diisocyanate is n + 1.

  The polyisocyanate polyurethane resin (I) having a terminal isocyanate group preferably has a solid content acid value of 20 to 200 mgKOH / g and more preferably 25 to 150 mgKOH / g in order to give a function of dispersing in water. Preferably, it is 30-120 mgKOH / g.

  The solid content acid value can be adjusted by adjusting the number of moles of the tertiary carboxyl group-containing diol compound.

  In this application document, a tertiary carboxyl group-containing diol compound is used as a polyol compound having an anionic polar group or nonionic polar chain dispersible in an aqueous medium in the molecule and having two or more hydroxyl groups. The acid value (AN) of the polyisocyanate polyurethane resin (I) when a diisocyanate compound is used as the isocyanate compound is calculated by the following formula.

(In the above formula, a1: mole number of a tertiary carboxyl group-containing diol compound such as dimethylolpropionic acid, A1: molecular weight of a tertiary carboxyl group-containing diol compound such as dimethylolpropionic acid, a2, a3... an: number of moles of other diols, A2, A3... An: molecular weight of other diols, b1, b2, b3... bn: number of moles of diisocyanate, B1, B2, B3. Molecular weight.)

  The number average molecular weight of the polyisocyanate polyurethane resin (I) when a diol compound is used as the polyol and a diisocyanate compound is used as the polyisocyanate compound can be calculated and adjusted by the following formula.

Number average molecular weight = nA ′ + (n + 1) B ′
(However, in the above formula, n is the total number of moles of polyols, A ′ is the number average molecular weight of polyols, and B ′ is the number average molecular weight of diisocyanate.)

The polyisocyanate polyurethane resin (I) has a number average molecular weight calculated by the above formula of preferably 1000 to 15000, more preferably 1300 to 10000, and still more preferably 1600 to 8000.
The polyisocyanate polyurethane resin (I) preferably has a solid content acid value of 20 to 120 mgKOH / g, more preferably 30 to 110 mgKOH / g, and still more preferably 35 to 100 mgKOH / g. .

  When a polyurethane resin is prepared using a polyol or polyisocyanate compound that is more than bifunctional as the polyol, the P.I. J It is desirable to adjust the molar fraction with reference to the Flory gelation formula to prevent gelation.

The polyisocyanate polyurethane resin (I) can be produced by bringing the polyols and polyisocyanate compound into contact with each other and urethane bonding. The contact temperature (reaction temperature) between the polyols and the polyisocyanate compound is The reaction temperature is preferably from 60 to 80 ° C., and the reaction can be carried out using any organic solvent known in the art and usually used for urethane reaction such as ethyl acetate, methyl ethyl ketone and acetonitrile.
Examples of the urethane reaction catalyst include known arbitrary catalysts such as a tertiary amine catalyst, dibutyltin laurate, stannous octylate, and the reaction can be carried out without a catalyst.

  The polyisocyanate polyurethane resin (I) has a terminal isocyanate group and has an anionic polar group or nonionic polar chain, and has an anionic polar group or nonionic polar chain in the molecular chain. preferable.

  The water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a hydroxyl group at the terminal is a polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group. And formed by contacting a primary amine or secondary amine (II) having a hydroxyl group.

  Examples of the primary amine or secondary amine (II) having a hydroxyl group include N-methylethanolamine, diethanolamine, 2- (hydroxymethylamino) ethanol, 4-methylaminobutanol, N-ethylethanolamine, Nt- Examples include but are not limited to butylethanolamine.

  When the polyisocyanate polyurethane resin (I) is reacted with a primary or secondary amine (II) having a hydroxyl group, in terms of solid content, based on 1 mol of the isocyanate group (NCO) of the polyisocyanate polyurethane resin (I). It is preferable to react the amino group of the primary or secondary amine (II) having a hydroxyl group in an amount corresponding to 0.50 to 1.10 mol, and an amount corresponding to 0.70 to 1.06 mol. It is more preferable to react, and it is more preferable to react an amount corresponding to 0.80 to 1.03 mol.

  The reaction between the polyisocyanate polyurethane resin (I) and the primary or secondary amine (II) having a hydroxyl group can be carried out in a known organic solvent, and the NCO group can be reacted under a temperature condition of 10 to 75 ° C. The reaction is preferably carried out so that the reaction rate is 95 to 100%.

In this application document, the NCO group reaction rate means a value measured according to JIS K-7301 6.3 “isocyanate group content”.
For example, when the polyisocyanate polyurethane resin (I) is added to the reaction vessel together with the primary or secondary amine (II) having a hydroxyl group, the reaction time is zero from the weight and the equivalent of the isocyanate group (NCO group). By calculating the NCO% at the time of non-reaction and further calculating the theoretical NCO% when all the isocyanate groups have reacted, the reaction rate of the NCO group can be determined.

  When the polyisocyanate polyurethane resin (I) is formed from a tertiary carboxyl group-containing polyol compound or the like, when phase-shifting the synthesized water-dispersible polyurethane resin (III) into an aqueous medium liquid, It is preferable to add a tertiary amine such as triethylamine, trimethylamine, N-methylmorpholine, tributylamine, N-methylpyrazine, or methylimidazole as appropriate.

  The water-dispersible polyurethane resin (III) preferably has a number average molecular weight of 1000 to 15000, more preferably 1300 to 10,000, as measured by a terminal group determination method in which amino groups are titrated with hydrochloric acid. 1600-8000 is more suitable.

  The water-dispersible polyurethane resin (III) preferably has a solid content acid value of 20 to 200 mgKOH / g, more preferably 25 to 150 mgKOH / g in order to give a function of dispersing in water. More preferred is 120 mg KOH / g.

  The polyurethane resin-attached pigment of the present invention comprises a water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a terminal hydroxyl group, and a pigment (IV) having an acidic group on the surface in an aqueous medium. It is made to contact.

In the polyurethane resin-attached pigment of the present invention, the pigment (IV) having an acidic group on the surface is preferably a pigment having an acidic surface. Various pigments that have been surface-treated with a synergist, and pigments that have been acidified by surface treatment are further treated. Mention may be made of pigments neutralized with ions.
In the polyurethane resin-attached pigment of the present invention, examples of the pigment (IV) having an acidic group on the surface include an inorganic pigment having an acidic group on the surface and a machine pigment having an acidic group on the surface. It can be used as a mixture of seeds.

  Examples of the inorganic pigment constituting the inorganic pigment having an acidic group on the surface include ivory black, peach black, lamp black, mars black, bitumen, titanium black, carbon black, etc. Is excellent in jetness and coloring power, so carbon black is suitable.

  Examples of carbon black include furnace black, channel black, acetylene black, and thermal black. These carbon blacks have a high carbon content and high blackness derived from an amorphous structure. Compared to black and the like, the drying rate is high, the storage stability is high, and the cost is low.

  Among the above-mentioned carbon blacks, ultrafine carbon blacks such as furnace black and channel black can provide high resolution and excellent print quality when used as an aqueous pigment dispersion in an ink composition for an ink jet printer.

The carbon black is preferably one nitrogen adsorption specific surface area _(N 2 SA) is ^{50 m} 2 / g or more, more preferably those wherein 50 to 300 m ² / g, still those that are 80~250m ² / g preferable. As the carbon black is preferably one DBP absorption is 50 cm ^3/100 g or more, more preferably those which are 50 to 200 cm ^3/100 g, more preferably those which are 80~180cm ³ / 100g.

Due to the N ₂ SA and DBP absorption amounts of carbon black being in the above range, when the obtained aqueous pigment dispersion is used in an inkjet ink composition, it has excellent dispersibility and ink performance with respect to an aqueous medium. It can be demonstrated.

Note that in the present application, N ₂ SA of carbon black is defined in JIS K6217-2 "Carbon black for rubber industry - basic characteristics - Part 2 Determination of specific surface area - nitrogen absorption method, a single-point method" The DBP absorption amount means a value measured according to “Carbon Black for Rubber—Basic Properties—Part 4, Determination of DBP Absorption” defined in JISK6217-4.

The average particle size of the primary particles constituting the carbon black is preferably 10 to 70 nm, more preferably 15 to 43 nm, and further preferably 18 to 30 nm.
In addition, in this application document, the average particle diameter of the primary particle which comprises carbon black means the arithmetic mean when the particle diameter of 2000-10000 primary particles is measured with the electron microscope with a resolution | decomposability of 15 or more.

The volume average particle size of carbon black is preferably 30 to 300 nm, more preferably 40 to 270 nm, and further preferably 50 to 250 nm.
In the present application documents, the volume average particle size of carbon black means a particle size of 50% (average particle size D50) as an integrated particle size in a volume-based integrated particle size distribution measured by a laser diffraction particle size distribution analyzer. To do.

  Specific examples of carbon black include Talker Black # 8500, Talker Black # 8500F, Talker Black # 7550SB, Talker Black # 7550F (manufactured by Tokai Carbon Co., Ltd.), # 650, # 750, MA600, # 44B, # 44. # 45B, MA7, MA11, # 47, # 45, # 33, # 45L, # 47, # 50, # 52, MA77, MA8 (manufactured by Mitsubishi Chemical Corporation), FW200, FW2V, FWI, FW18PS, NIpex180IQ, FW1, Special Black6, S160, S170 (above Degussa), Black Pearls 1000M, Black Pearls 800, Black Pearls 880, Monarch 1300, Monarch 700, Monarch 80 , CRX 1444, Regal 330R, Regal 660R, Regal 660, Regal 415R, Regal 415, Black Pearls 4630, Monarch 4630 (above made by Cabot), Raven 7000, Raven 3500, Raven 5250, Raven 5250, Raven 5250, Raven 5250, Raven 5250 Raven 1255, Raven 1250, Raven 1190, Raven 1000, Raven 1020, Raven 1035, Raven 1100ULTRA, Raven 1170, Raven 1200 (manufactured by Columbian, Inc., 700, U.S.A., 7) 725, 300, 305 320, 325, X25, X45 (above Asahi Carbon Co., Ltd.), N220, N110, N234, N121 (above Sid Richardson), Niteron # 300 (above Nisshin Carbon Co., Ltd.), Show Black N134, N110, N220, N234, N219 (manufactured by Showa Cabot Co., Ltd.) can be used.

  Examples of the organic pigment constituting the organic pigment having an acidic group on the surface 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, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (eg basic dye chelates, acidic dye chelates), nitro pigments, nitroso pigments, anilines Black etc. can be used.

  Specific examples of the pigment are appropriately given according to the type (color) of the ink composition. For example, as a yellow pigment, C.I. I. Pigment Yellow 1, 2, 3, 12, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 128, 129, 138, 139, 147, 150, 151, 154, 155, 180, 185 and the like, and one or more of these are used. Of these, C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Yellow 74, 110, 128 and 147. Examples of magenta pigments include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 168, 184, 202, 209; I. Pigment violet 19 or the like, and one or more of these may be used. Of these, C.I. I. Pigment red 122, 202, 209 and C.I. I. It is preferable to use one or more selected from the group consisting of CI Pigment Violet 19. Examples of cyan pigments include C.I. I. Pigment Blue 1, 2, 3, 15: 3, 15: 4, 15:34, 16, 22, 60; I. Vat Blue 4, 60 and the like are listed, and one or more of these are used. Of these, C.I. I. Pigment Blue 15: 3 and / or 15: 4 are preferably used, especially C.I. I. Pigment Blue 15: 3 is preferably used.

  In the polyurethane resin-attached pigment of the present invention, the pigment (IV) having an acidic group on the surface is acidic on the surface by a method of oxidizing each pigment with an oxidizing agent, a method of sulfonation, a method of reacting a diazonium salt, or the like. Groups can be introduced.

  The oxidation treatment can be performed by a known method such as a liquid phase method or a gas phase method. When oxidizing by the liquid phase method, various oxidizing agents such as hydrogen peroxide, nitric acid, sulfuric acid, chlorate, persulfate, percarbonate can be used as the oxidizing agent. A pigment having an acidic group on the surface can be obtained by introducing the pigment into an aqueous solution containing and stirring, and by uniformly controlling the amount of the oxidizing agent and the reaction temperature, the acidic group is uniformly formed on the pigment surface. Can be introduced.

  Further, the oxidation treatment by the gas phase method can include a method by ozone oxidation or air oxidation. According to the gas phase method, the drying cost is not required and the operation is easier than the liquid phase method. There are advantages.

  As the pigment (IV) having an acidic group on the surface, a self-dispersing pigment having an acidic group on the surface is appropriate, and in consideration of the dispersibility and ejection stability of the ink composition, the surface is particularly suitable. One or more kinds selected from a self-dispersing carbon black having an acidic group and a self-dispersing organic pigment having an acidic group on the surface are suitable.

  A self-dispersing pigment having an acidic group on the surface is a pigment in which at least one hydrophilic group containing an acidic group is bonded to the surface of the pigment directly or via another atomic group, and is suspended in water. This means that a stable dispersion state can be maintained without adding a surfactant or a polymer compound when a dispersion is made, and the surface tension of the dispersion shows almost the same value as water. In the application documents, the self-dispersing pigment includes those obtained by neutralizing a hydrophilic group such as the acidic group with a counter ion.

The acidic functional group in the self-dispersing _{pigment, -COOM, -SO 3 M, -PO} 3 HM, -PO 3 M 2, -CONM 2, -SO 3 NM 2, -NH-C 6 H 4 -COOM, _{-NH-C 6 H 4 -SO 3} M, -NH-C 6 H 4 -PO 3 HM, -NH-C 6 H 4 -PO 3 M 2, -NH-C 6 H 4 -CONM 2, -NH -C ₆ H ₄ can be mentioned _{-SO 3 NM 2, -COOM, -SO} 3 M, -PO 3 HM, -PO 3 M 2, -SO 2 NH 2, -SO 2 NHCOR are particularly preferred (although , M represents a hydrogen atom, an alkali metal, an organic ammonium, a quaternary ammonium or a tertiary amine).

  When M in the acidic functional group is an alkali metal, examples of M include lithium, sodium, and potassium.

  When M in the acidic functional group is organic ammonium, examples of M include mono to trimethyl ammonium, mono to triethyl ammonium, and mono to trimethanol ammonium.

  When M in the acidic functional group is quaternary ammonium, examples of M include ammonia, tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, tetrapentylammonium, benzyltrimethylammonium, and benzyltriethylammonium. And tetrahexylammonium. Among these, tetraethylammonium, tetrabutylammonium, and benzyltrimethylammonium are particularly preferable.

  When M in the acidic functional group is a tertiary amine, M is triethylamine, trimethylamine, N-methylmorpholine, tributylamine, N-methylpyrazine, methylimidazole, N′N-diethylethanolamine, N ′. N-dimethylethanolamine etc. are mentioned. Among these, triethylamine, trimethylamine, and N-methylmorpholine are particularly preferable.

  In general, when self-dispersing pigments having acidic groups on the surface are neutralized by counterions, the pigment particles are dispersed by repulsion of ions, and when a polymer is added to the surface, the storage stability can be improved. When the concentration of acidic groups on the pigment surface is low, dispersion stability is lacking. On the other hand, the polyurethane resin-attached pigment of the present invention is particularly suitable for the pigment (IV) having an acidic group on the surface, even when the acidic group concentration on the surface of the pigment (IV) having an acidic group on the surface is low. By attaching the water-dispersible polyurethane resin (III), the water-dispersible polyurethane resin (III) is converted into an anionic polar group or nonionic polar chain derived from the polyisocyanate polyurethane resin (I), and a primary amine. Alternatively, since it has a hydroxyl group derived from secondary amine (II), it can exhibit excellent dispersibility and dispersion stability.

  When the pigment (IV) having an acidic group on the surface is carbon black having an acidic group on the surface, the carboxyl group equivalent is preferably 200 to 1200 μmol / g, more preferably 400 to 1000 μmol / g, What is 600-800 micromol / g is still more preferable.

  Commercially available products may be used as the pigment (IV) having an acidic group on the surface, such as AquaBlack (registered trademark) 162, AquaBlack (registered trademark) 164 (both manufactured by Tokai Carbon Co., Ltd.), CAB-O-JET. (Registered trademark) 200, CAB-O-JET (registered trademark) 250C, CAB-O-JET (registered trademark) 260M, CAB-O-JET (registered trademark) 270Y, CAB-O-JET (registered trademark) 300, CAB-O-JET (registered trademark) 400, CAB-O-JET (registered trademark) 450C, CAB-O-JET (registered trademark) 465M and CAB-O-JET (registered trademark) 470Y (all of which are Cabot Specialty Chemicals), BONJET (registered trademark) BLACK CW-2 and BONJET (registered trademark) BRAC K CW-3 (both manufactured by Orient Chemical Co., Ltd.) and the like can be mentioned.

The pigment (IV) having an acidic group on the surface has a volume average particle diameter of the pigment when dispersed in water of preferably 30 to 300 nm, more preferably 40 to 270 nm, and more preferably 50 to 250 nm. Is more preferable.
In the present application documents, the volume average particle size of the pigment (IV) having an acidic group on the surface is 50% of the cumulative particle size in the volume-based cumulative particle size distribution measured by a laser diffraction particle size distribution analyzer. (Average particle diameter D50) is meant.

  The polyurethane resin-attached pigment of the present invention is obtained by contacting a water-dispersible polyurethane resin (III) with a pigment (IV) having an acidic group on the surface in an aqueous medium.

  The aqueous medium is preferably water, and the aqueous medium other than water is water-soluble, such as acetonitrile, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, or the like, and does not react with amines or isocyanates. A solvent is preferred. Specific examples include glycol-based aqueous solvents such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol, dimethyl sulfoxide, sulfolane, and the like. It may be.

The pigment (IV) having an acidic group on the surface is preferably brought into contact with the water-dispersible polyurethane resin (III) in a slurry state with an aqueous medium added.
When the pigment (IV) having an acidic group on the surface is in the form of a slurry, examples of the aqueous medium include those described above. The concentration of the pigment (IV) having an acidic group on the surface in the slurry is preferably 3 to 30% by mass, more preferably 4 to 28% by mass, and 5 to 25% by mass. Is more preferable.
When the concentration of the pigment (IV) having an acidic group on the surface in the slurry is within the above range, the water-dispersible polyurethane resin (III) is added to the slurry in a predetermined amount, whereby the acidic group is formed on the surface. Reaction with the pigment (IV) it has can be performed easily.

  The polyurethane resin-attached pigment of the present invention is formed by bringing a water-dispersible polyurethane resin (III) and a pigment (IV) having an acidic group on the surface into contact with each other in an aqueous medium at a temperature of 20 to 60 ° C. It is preferable to form it by contacting at room temperature. Moreover, the contact time of both is preferably 0.25 to 1 hour, and is preferably formed by stirring and mixing.

  The polyurethane resin-attached pigment of the present invention preferably contains 3 to 200 parts by mass of the water-dispersible polyurethane resin (III) with respect to 100 parts by mass of the pigment (IV) having an acidic group on the surface in terms of solid content. 5 to 150 parts by mass are more preferable, and 7 to 100 parts by mass are further preferable.

  When the reaction amount of the water-dispersible polyurethane resin (III) with respect to 100 parts by mass of the pigment (IV) having an acidic group on the surface is less than 3 parts by mass, it is difficult to improve dispersion stability, image density, and scratch resistance. , Tend to cause thickening of the whole solution. When the reaction amount of the water-dispersible polyurethane resin (III) with respect to 100 parts by mass of the pigment (IV) having an acidic group on the surface exceeds 200 parts by mass, the mass fraction of the pigment (IV) having an acidic group on the surface is As a result, the image density tends to decrease.

The polyurethane resin-attached pigment of the present invention is obtained by bringing a primary or secondary amine (II) having a hydroxyl group into contact with a polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group. The water-dispersible polyurethane resin (III) having a urea bond in the molecule and having a hydroxyl group at the terminal and the pigment (IV) having an acidic group on the surface are contacted in an aqueous medium.
For this reason, the polyurethane resin-attached pigment of the present invention is obtained by physically adsorbing the low-polar main chain of the water-dispersible polyurethane resin (III) to the pigment (IV) having an acidic group on the surface, and the water-dispersible polyurethane. The hydroxyl group, anionic polar group or nonionic polar chain of the resin (III) exhibits an affinity for an aqueous medium, and the water-dispersible polyurethane resin (III) functions as a kind of pigment dispersant to make the pigment (IV) aqueous. Since it is dispersed in a medium, the image density is excellent, and the dispersion stability, storage stability, and re-dissolvability of the pigment can be improved.
The polyurethane resin-attached pigment of the present invention is such that the water-dispersible polyurethane resin (III) constituting the polyurethane resin-attached pigment of the present invention is a primary amine or a secondary amine at the terminal isocyanate group of the polyurethane resin (I). Since the urea bond is formed by contacting (II), a tough ink coating film can be formed by this urea bond, and the marker resistance and scratch resistance of the ink coating film can be improved. .

  Next, the pigment dispersion composition of the present invention will be described. The pigment dispersion composition of the present invention comprises the polyurethane resin-attached pigment of the present invention.

  The pigment dispersion composition of the present invention was dispersed in water and additives such as any known moisturizer, preservative, emulsifier, pH adjuster, antifoaming agent, coating film surface smoothing agent and the like together with the polyurethane resin adhesion pigment of the present invention. Waxes, resin emulsions, aqueous dispersion resins and the like can be included.

  Examples of the humectant include one or more selected from polyoxyalkylene ether glycols such as glycerin, diethylene glycol, triethylene glycol, and dipropylene glycol, or monoalkyl ethers and dialkyl ethers of polyoxyalkylene ether glycols.

  As the aqueous dispersion resin, self-emulsification of acrylic emulsion, latex, aqueous resin, etc., self-dispersing polymerized water-dispersion resin, and monomers constituting these resins are emulsified or dispersed with emulsifier to form particles. An emulsion type water-dispersed resin obtained by polymerization in the particles can be mentioned.

Polymeric water-dispersed resins include crotonic acid and itaconic acid. Vinyl polymerizations such as fumaric acid, maleic acid and other unsaturated groups and their esters, styrene, vinyl acetate, versatic acid vinyl ester, (meth) acrylic acid, (meth) acrylic acid ester, sodium styrene sulfonate And those obtained by copolymerization of the functional monomer.
Examples of the emulsion-type polymerized water-dispersed resin include those in which the above-mentioned polymerized water-dispersed resin is contained in an emulsifier.

  Examples of the aqueous dispersion resin include self-dispersion and self-emulsification resins such as epoxy ester resins, vinyl-modified epoxy resins, high acid value alkyd resins, vinyl-modified water alkyd resins, water-based polyester resins, and water-based polyurethane resins. Examples thereof include a core-shell type obtained by forming particles using a resin as an emulsifier and polymerizing different types of monomers in the particles.

  The epoxy ester resin has a carboxyl group in the molecule obtained by reacting an acid anhydride with an epoxy ester obtained by reacting an epoxy group of an epoxy resin with a fatty acid having an unsaturated double bond with a hydroxyl group. Examples thereof include those obtained by neutralizing a polymer with a counter ion.

  As the vinyl-modified epoxy resin, a vinyl polymerizable monomer is used for the unsaturated double bond of the fatty acid of the epoxy ester resin obtained by reacting the fatty acid having an unsaturated double bond with the epoxy group or hydroxyl group of the epoxy resin. Mention may be made of vinyl-modified epoxy ester resins obtained by copolymerization.

  Examples of the high acid value alkyd resin include those obtained from a condensation reaction product of a polycarboxylic acid compound obtained by acidolysis of a polybasic acid and an oil and a monoalcohol, diol, or polyol.

  As the vinyl-modified aqueous alkyd resin, the polymerization described above is performed for the unsaturated double bond in the oil and fat component of the alkyd resin produced by condensation of a polybasic acid with a compound obtained by alcoholysis of polyhydric alcohol and fat. The thing obtained by copolymerizing the vinyl polymerizable monomer used as the raw material of the aqueous dispersion resin can be exemplified.

  As an aqueous polyester resin, for example, a dialkanol alkanoic acid such as dimethylolpropionic acid or dimethylolbutanoic acid having a hydroxyl group and a tertiary carboxyl group in the molecule is reacted with a dibasic acid as a part of the diol component. Things can be mentioned.

  The water-based polyester resin is a polyoxyethylene ether glycol for introducing a hydrophilic group, a tertiary carboxyl group-containing polyol compound or polyol, one or more selected from polyol effective components, polybasic acids, anhydrides thereof, and the like. It can also be obtained by condensation reaction with one or more, and the polyester in which an acid is introduced into the molecular chain can be neutralized with a counter ion.

  Examples of the tertiary carboxyl group-containing polyol compound used as the raw material for the aqueous polyester resin include polyhydroxycarboxylic acids such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolacetic acid, dimethylolbutyric acid, dimethylolvaleric acid, and dimethylolcaproic acid. Of these, dihydroxymonocarboxylic acids such as dimethylolpropionic acid and dimethylolbutanoic acid are preferred.

  Examples of the polyol used as a raw material for the aqueous polyester resin include ethylene glycol, propylene glycol, cyclohexane-1,4-dimethanol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1 , 6-hexanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8 -Octanediol, 1,9-nonanediol, cyclohexanedimethanol, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, castor oil-modified diol, castor oil-modified polyol, and the like.

  Polyol synergistic components used as raw materials for the aqueous polyester resin include alkyl monoglycidyl ethers such as butyl glycidyl ether, 2-ethylhexyl glycidyl ether, lauryl glycidyl ether, decyl glycidyl ether and stearyl glycidyl ether, and alkyl glycidyl esters (products). 1 type or 2 or more types of monoepoxy compounds, such as the name Cardura E10: Shell Japan Co., Ltd.).

  Examples of the polybasic acids and their anhydrides used as the raw material for the aqueous polyester resin include aliphatic dibasic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid and dimer acid, and their anhydrides, dodecenyl succinic anhydride. Aromatic polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid and trimellitic anhydride, and anhydrides thereof, alicyclic polybasic acids such as hydrophthalic anhydride and dimethyl-1,4-cyclohexanedicarboxylic acid, and These anhydrides are mentioned.

As an emulsifier-dispersed aqueous dispersion resin used as an aqueous dispersion resin, an emulsion-type polymerized water-dispersed resin obtained by emulsifying or dispersing a resin monomer with an emulsifier to form particles and polymerizing within the particles, or the above Examples thereof include a core-shell type emulsion in which a resin called a self-dispersing type or a self-emulsifying type is used as an emulsifier to polymerize and form different types of polymers in the particles.
The emulsifier is preferably at least one selected from an anionic emulsifier and a nonionic emulsifier.

  As the aqueous dispersion resin, those dispersed in an aqueous medium such as water are preferable, and examples of the aqueous medium include the same ones as described above.

In the pigment dispersion composition of the present invention, the average particle size of the aqueous dispersion resin is preferably 10 to 300 nm, more preferably 20 to 250 nm, and even more preferably 30 to 200 nm.
In the present application documents, the volume average particle size of the aqueous dispersion resin is a 50% mode diameter (50% particle size in the volume-based cumulative particle size distribution) measured by a dynamic light scattering particle size distribution analyzer. (Average particle diameter D50)).

  The pigment dispersion composition of the present invention can easily improve coating film performance such as scratch resistance and marker resistance by including an aqueous dispersion resin together with the polyurethane resin adhesion pigment of the present invention.

  When the aqueous dispersion resin is added, the pigment dispersion composition of the present invention preferably contains 1 to 20% by mass, more preferably 2 to 19% by mass of the aqueous dispersion resin in terms of solid content. 3 to 18% by mass is more preferable.

  The pigment dispersion composition of the present invention is, for example, added to the stirring resin in the stirring vessel while adding the polyurethane resin adhesion pigment of the present invention, and if necessary, an aqueous dispersion resin, a humectant, a preservative, an emulsifier, pH Add additives such as regulator, antifoaming agent, coating surface smoothing agent, wax dispersed in water, resin emulsion, etc., stir and adjust viscosity with water or water-soluble organic solvent as necessary It can be produced by filtering by any known filtration method.

  In the pigment dispersion composition of the present invention, the pigment concentration (mass ratio of pigment (IV) in the composition) can be appropriately selected according to the type of pigment and the purpose of use of the pigment dispersion composition. In terms of minutes, it is 2 to 30% by mass, and when used as an ink jet ink composition, it is suitably 2 to 15% by mass.

  According to the pigment dispersion composition of the present invention, excellent image density, dispersibility, storage stability, re-dissolvability, marker resistance and scratch resistance of the ink coating film can be exhibited.

Next, the inkjet ink composition of the present invention will be described.
The inkjet ink composition of the present invention includes the polyurethane resin-attached pigment of the present invention.
The inkjet ink composition of the present invention is the same as the pigment dispersion composition of the present invention except that its application is limited to inkjet ink applications, and the details thereof are the same as those described above.
According to the inkjet ink composition of the present invention, it is possible to exhibit excellent image density, dispersibility, storage stability, re-dissolvability, marker resistance and scratch resistance of the ink coating film.

  The contents of the present invention will be described below with specific examples. However, the present invention is not limited to the contents of these examples.

(Synthesis of water-dispersible polyurethane resin A)
In a flask equipped with a stirrer, a nitrogen blowing tube and a ball cooling tube, 240 parts by mass of methyl ethyl ketone (MEK), 31.1 parts by mass of dimethylolpropionic acid [2.3 molar ratio], polytetramethylene ether glycol PTG- 82.9 parts by mass (0.8 molar ratio) of L1000 (number average molecular weight 1028, manufactured by Hodogaya Chemical Co., Ltd.), tetrahydrofuran-neopentyl glycol copolymer PTXG-1800 (number average molecular weight 1850, Asahi Kasei Fibers ( 93.2 parts by mass [0.5 molar ratio] and 40.8 parts by mass [0.4 molar ratio] of polyethylene ether glycol # 1000 (manufactured by NOF Corporation, number average molecular weight 1011). In addition, 112 parts by mass [5.0 molar ratio] of isophorone diisocyanate (Desmodur I manufactured by Sumika Bayer Urethane Co., Ltd.) 5 and reacted for 6 hours at ° C., was synthesized anionic polar group and a nonionic polar chain end isocyanate groups and having a polyisocyanate polyurethane resin having a (NCO group) (I).
At this time, the ratio of the number of moles of hydroxyl groups (OH groups) to the number of moles of NCO groups in the reaction solution (number of moles of OH groups / number of moles of NCO groups) was 4/5, and the mass% of NCO groups was 1.58. %Met.

Furthermore, 18.6 parts by mass [0.8 molar ratio] of 4-methylaminobutanol as a primary amine or secondary amine (II) having a hydroxyl group was added [0.8 molar ratio], and 200 parts by mass of methyl ethyl ketone (MEK) was added. The reaction was carried out at 2 ° C. for 2 hours. At this time, the mass% of the isocyanate group in the reaction solution of the reaction product was 0.01%, and the solid content acid value was 38.2 mgKOH / g.
Then, it cooled to 35 degreeC, 25 mass parts of N-methylmorpholine was added, it stirred for 30 minutes, and the phase was changed into ion-exchange water. By distilling off MEK as a reaction solvent using an evaporator, a water-dispersible polyurethane resin A having a hydroxyl terminal at the terminal and a urea bond and a nonionic polar chain in the polymer chain was obtained.
The obtained water-dispersible polyurethane resin A had a nonvolatile content of 30.0% by mass, a Gardner cell viscosity: AB, a number average molecular weight by GPC of 3572, and a mass average molecular weight of 10870. .

(Synthesis of water-dispersible polyurethane resin B)
In a flask equipped with a stir bar, nitrogen gas blowing tube and ball cooling tube, 240 parts by mass of methyl ethyl ketone (MEK), 34.0 parts by mass of dimethylolpropionic acid [2.6 molar ratio], polytetramethylene ether glycol PTG- L1000 (number average molecular weight 1028, manufactured by Hodogaya Chemical Co., Ltd.) 80.2 parts by mass [0.8 molar ratio], Kuraray polyester diol P-1050 (number average molecular weight 994, manufactured by Kuraray Co., Ltd.) 90 .2 parts by mass [0.9 mol ratio], polyethylene ether glycol # 1000 (manufactured by NOF Corporation, number average molecular weight 1011) is added to 69.0 parts by mass [0.7 mol ratio] and isophorone diisocyanate (Suika Bayer). Add 86.7 parts by mass (4.0 molar ratio) of Death Module I) manufactured by Urethane Co., Ltd. A polyurethane resin having a polar group and a nonionic polar chain and having a hydroxyl terminal was synthesized.
The mass% of isocyanate groups in the reaction solution at this time was 0.01% by mass. The solid content acid value of this reaction product was 39.7 mgKOH / g.

Then, after cooling to 35 ° C. and adding 26 parts by mass of N-methylmorpholine and stirring for 30 minutes, the phase was changed into ion-exchanged water, and MEK was distilled off by an evaporator, thereby having a hydroxyl group at the terminal and nonion. A water-dispersible polyurethane resin B having a hydrophilic polar chain was obtained.
The obtained water-dispersible polyurethane resin B does not have a urea bond in the polymer chain, has a nonvolatile content of 30.1% by mass, Gardner cell viscosity: BC, number average molecular weight 2870 by GPC, mass average molecular weight 9828, The ratio of the number of moles of OH groups to the number of moles of NCO groups (number of moles of OH groups / number of moles of NCO groups) was 6/5.

(Example 1) Preparation of polyurethane resin-attached black pigment 1 As a pigment (IV) having an acidic group on the surface, AquaBlack (registered trademark) 162 (produced by Tokai Carbon Co., Ltd.), which is a carbon black pigment having an acidic group on the surface. The water-dispersible polyurethane resin A (non-volatile content: 30.0% by mass) as a water-dispersible polyurethane resin (III) with respect to 1000 parts by mass of a solid content concentration of 19.3% by mass and a carboxyl group equivalent of 800 micromol / g) By adding 322 parts by mass and stirring at 40 ° C. for 60 minutes, an aqueous dispersion of polyurethane resin-attached pigment 1 having a solid content concentration of 22% by mass was obtained.
In the obtained polyurethane resin-attached pigment 1, the mass ratio of the pigment (IV) to the water-dispersible polyurethane resin (III) (the mass of the pigment (IV) / the mass of the water-dispersed polyurethane resin (III)) is calculated in terms of solid content. 100/50.

<Preparation of inkjet ink composition>
The dispersion of the resin-attached pigment was weighed so as to have the composition shown in Table 1, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 1. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Example 2) Production of polyurethane resin-attached yellow pigment 1 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 270Y (manufactured by Cabot Corporation, solid concentration 11.0% by mass) 1000 By adding 183.3 parts by mass of the water-dispersible polyurethane resin A (non-volatile content: 30.0% by mass) as the water-dispersible polyurethane resin (III) with respect to parts by mass, and stirring at 40 ° C. for 60 minutes, An aqueous dispersion of polyurethane resin-attached yellow pigment 1 having a solid content concentration of 13.9% by mass was obtained.
In the obtained polyurethane resin-attached yellow pigment 1, the mass ratio of the pigment (IV) having an acidic group on the surface to the water-dispersible polyurethane resin (III) (the mass of the pigment (IV) having an acidic group on the surface / water-dispersed polyurethane) The mass of the resin (III) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The dispersion of the resin-attached pigment was weighed so as to have the composition shown in Table 1, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 1. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Example 3) Production of polyurethane resin-attached magenta pigment 1 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 265M (manufactured by Cabot Corporation, solid content concentration 11.0% by mass) 1000 By adding 183.3 parts by mass of the water-dispersible polyurethane resin A (non-volatile content: 30.0% by mass) as the water-dispersible polyurethane resin (III) with respect to parts by mass, and stirring at 40 ° C. for 60 minutes, An aqueous dispersion of polyurethane resin-attached magenta pigment 1 having a solid content concentration of 13.9% by mass was obtained.
The mass ratio of the pigment (IV) having an acidic group on the surface to the water-dispersible polyurethane resin (III) (the mass of the pigment (IV) having an acidic group on the surface / water-dispersed polyurethane) The mass of the resin (III) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The dispersion of the resin-attached pigment was weighed so as to have the composition shown in Table 1, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 1. And Olfine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

Example 4 Production of Cyan Pigment 1 Adhering to Polyurethane Resin As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 250C (manufactured by Cabot Corporation, solid concentration 11.0% by mass) 1000 By adding 183.3 parts by mass of the water-dispersible polyurethane resin A (non-volatile content: 30.0% by mass) as the water-dispersible polyurethane resin (III) with respect to parts by mass, and stirring at 40 ° C. for 60 minutes, An aqueous dispersion of polyurethane resin-attached cyan pigment 1 having a solid content concentration of 13.9% by mass was obtained.
In the obtained polyurethane resin-attached cyan pigment 1, the mass ratio of the pigment (IV) having an acidic group on the surface to the water-dispersible polyurethane resin (III) (the mass of the pigment (IV) having an acidic group on the surface / water-dispersed polyurethane) The mass of the resin (III) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The dispersion of the resin-attached pigment was weighed so as to have the composition shown in Table 1, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 1. And Olfine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 1) Preparation of polyurethane resin-attached black pigment 2 As a pigment (IV) having an acidic group on the surface, AquaBlack (registered trademark) 162 (manufactured by Tokai Carbon Co., Ltd., solid content concentration 19.3) is a carbon black pigment. 320.6 parts by mass of the water-dispersible polyurethane resin B (non-volatile content: 30.1% by mass) is added to 1000 parts by mass of a mass% and a carboxyl group equivalent of 800 micromol / g), and the mixture is stirred at 40 ° C. for 60 minutes. As a result, an aqueous dispersion of polyurethane resin-attached black pigment 2 having a solid content concentration of 21.9% by mass was obtained.
In the obtained polyurethane resin-attached black pigment 2, the mass ratio of the pigment (IV) having acidic groups on the surface to the water-dispersible polyurethane resin B (mass of pigment (IV) having acidic groups on the surface / water-dispersed polyurethane resin B Mass) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The resin adhering pigment dispersion was weighed so as to have the composition shown in Table 2, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative example 2) Preparation of polyurethane resin-attached yellow pigment 2 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 270Y (manufactured by Cabot Corporation, solid concentration 11.0% by mass) 1000 By adding 182.7 parts by mass of the water-dispersible polyurethane resin B (non-volatile content: 30.1% by mass) with respect to parts by mass and stirring at 40 ° C. for 60 minutes, the solid content concentration is 13.9% by mass. An aqueous dispersion of a certain polyurethane resin-attached yellow pigment 2 was obtained.
In the obtained polyurethane resin-attached yellow pigment 2, the mass ratio of the pigment (IV) having acidic groups on the surface to the water-dispersible polyurethane resin B (mass of pigment (IV) having acidic groups on the surface / water-dispersed polyurethane resin B Mass) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The resin adhering pigment dispersion was weighed so as to have the composition shown in Table 2, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 3) Preparation of polyurethane resin-attached magenta pigment 2 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 265M (manufactured by Cabot Corporation, solid concentration 11.0% by mass) 1000 By adding 182.7 parts by mass of the water-dispersible polyurethane resin B (non-volatile content: 30.1% by mass) with respect to parts by mass and stirring at 40 ° C. for 60 minutes, the solid content concentration is 13.9% by mass. An aqueous dispersion of a polyurethane resin-attached magenta pigment 2 was obtained.
In the obtained magenta polyurethane resin-attached magenta pigment 2, the mass ratio of the pigment (IV) having acidic groups on the surface to the water-dispersible polyurethane resin B (mass of pigment (IV) having acidic groups on the surface / water-dispersed polyurethane resin B Mass) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The resin adhering pigment dispersion was weighed so as to have the composition shown in Table 2, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 4) Production of polyurethane resin-attached cyan pigment 2 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 250C (manufactured by Cabot Corporation, solid content concentration 11.0% by mass) 1000 By adding 182.7 parts by mass of the water-dispersible polyurethane resin B (non-volatile content: 30.1% by mass) with respect to parts by mass and stirring at 40 ° C. for 60 minutes, the solid content concentration is 13.9% by mass. An aqueous dispersion of a polyurethane resin-attached cyan pigment 2 was obtained.
In the obtained polyurethane resin-attached cyan pigment 2, the mass ratio of the pigment (IV) having acidic groups on the surface to the water-dispersible polyurethane resin B (mass of pigment (IV) having acidic groups on the surface / water-dispersed polyurethane resin B Mass) was 100/50 in terms of solid content.

<Preparation of inkjet ink composition>
The dispersion of the resin-attached pigment was weighed so as to have the composition shown in Table 2, and further, 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 5) Production of Black Pigment 3 with Addition of Styrene Acrylic Resin As a pigment (IV) having an acidic group on the surface, AquaBlack (registered trademark) 162 (solid content concentration 19.2% by mass, carboxyl group equivalent 800 μmol / g) ) Addition of 313.7 parts by mass of 1000 parts by mass of Jonkrill 61J (non-volatile content: 30.6% by mass, manufactured by BASF Japan), which is a styrene-acrylic resin emulsion, and stirring for 60 minutes results in a solid content of 21 An aqueous dispersion of styrene acrylic resin-added black pigment 3 in an amount of 0.9 mass% was obtained.
In the obtained styrene acrylic resin-added black pigment 3, the mass ratio of the pigment (IV) having an acidic group on the surface to the styrene acrylic resin (the mass of the pigment (IV) having an acidic group on the surface / the mass of the styrene acrylic resin) is The solid content was 100/50.

<Preparation of inkjet ink composition>
The resin-added pigment dispersion was weighed so as to have the composition shown in Table 2, and further 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 6) Preparation of styrene acrylic resin-added yellow pigment 3 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 270Y (manufactured by Cabot Corporation, solid content concentration 11.0% by mass) A solid content concentration of 14 by adding 179.7 parts by mass of Jonkrill 61J (non-volatile content: 30.6% by mass, manufactured by BASF Japan), which is a styrene-acrylic resin emulsion, to 1000 parts by mass and stirring for 60 minutes. An aqueous dispersion of styrene acrylic resin-added yellow pigment 3 of 0.0 mass% was obtained.
In the obtained styrene acrylic resin-added yellow pigment 3, the mass ratio of the pigment (IV) having an acidic group on the surface to the styrene acrylic resin (the mass of the pigment (IV) having an acidic group on the surface / the mass of the styrene acrylic resin) is The solid content was 100/50.

<Preparation of inkjet ink composition>
The resin-added pigment dispersion was weighed so as to have the composition shown in Table 2, and further 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 7) Preparation of styrene acrylic resin-added magenta pigment 3 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 265M (manufactured by Cabot Corporation, solid content concentration 11.0% by mass) A solid content concentration of 14 by adding 179.7 parts by mass of Jonkrill 61J (non-volatile content: 30.6% by mass, manufactured by BASF Japan), which is a styrene-acrylic resin emulsion, to 1000 parts by mass and stirring for 60 minutes. An aqueous dispersion of styrene acrylic resin-added magenta pigment 3 of 0.0 mass% was obtained.
In the obtained styrene acrylic resin-added magenta pigment 3, the mass ratio of the pigment (IV) having an acidic group on the surface to the styrene acrylic resin (the mass of the pigment (IV) having an acidic group on the surface / the mass of the styrene acrylic resin) is The solid content was 100/50.

<Preparation of inkjet ink composition>
The resin-added pigment dispersion was weighed so as to have the composition shown in Table 2, and further 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

(Comparative Example 8) Production of styrene acrylic resin-added cyan pigment 3 As pigment (IV) having an acidic group on the surface, CAB-O-JET (registered trademark) 250C (manufactured by Cabot Corporation, solid content concentration 11.0% by mass) A solid content concentration of 14 by adding 179.7 parts by mass of Jonkrill 61J (non-volatile content: 30.6% by mass, manufactured by BASF Japan), which is a styrene-acrylic resin emulsion, to 1000 parts by mass and stirring for 60 minutes. An aqueous dispersion of cyan pigment 3 having a styrene acrylic resin content of 0.0 mass% was obtained.
In the obtained styrene acrylic resin-added cyan pigment 3, the mass ratio of the pigment (IV) having an acidic group on the surface to the styrene acrylic resin (the mass of the pigment (IV) having an acidic group on the surface / the mass of the styrene acrylic resin) is The solid content was 100/50.

<Preparation of inkjet ink composition>
The resin-added pigment dispersion was weighed so as to have the composition shown in Table 2, and further 1,5-pentadiol, glycerin, diethylene glycol diethyl ether, thickener 621N (San Nopco) so as to have the composition shown in Table 2. And Olfin E1010 (manufactured by Nissin Chemical Industry Co., Ltd.) were weighed and stirred at room temperature for 60 minutes, so that the pigment concentration was 5% by mass (solid content concentration 7.5% by mass). An inkjet ink composition was prepared.

（表１において、「黒色顔料１」は、ポリウレタン樹脂付着黒色顔料１を意味するものとし、「イエロー顔料１」は、ポリウレタン樹脂付着イエロー顔料１を意味するものとし、「マゼンタ顔料１」は、ポリウレタン樹脂付着マゼンタ顔料１を意味するものとし、「シアン顔料１」は、ポリウレタン樹脂付着シアン顔料１を意味するものとする。）

(In Table 1, “black pigment 1” means a polyurethane resin-attached black pigment 1, “yellow pigment 1” means a polyurethane resin-attached yellow pigment 1, and “magenta pigment 1” (The polyurethane resin-attached magenta pigment 1 is meant, and “cyan pigment 1” means the polyurethane resin-attached cyan pigment 1.)

（表２において、「黒色顔料２」は、ポリウレタン樹脂付着黒色顔料２を意味するものとし、「イエロー顔料２」は、ポリウレタン樹脂付着イエロー顔料２を意味するものとし、「マゼンタ顔料２」は、ポリウレタン樹脂付着マゼンタ顔料２を意味するものとし、「シアン顔料２」は、ポリウレタン樹脂付着シアン顔料２を意味するものとする。また、表２において、「黒色顔料３」は、スチレンアクリル樹脂添加黒色顔料３を意味するものとし、「イエロー顔料３」は、スチレンアクリル樹脂添加イエロー顔料３を意味するものとし、「マゼンタ顔料３」は、スチレンアクリル樹脂添加マゼンタ顔料３を意味するものとし、「シアン顔料３」は、スチレンアクリル樹脂添加シアン顔料３を意味するものとする。）

(In Table 2, “black pigment 2” means polyurethane resin-attached black pigment 2, “yellow pigment 2” means polyurethane resin-attached yellow pigment 2, and “magenta pigment 2” The magenta pigment 2 adhered to the polyurethane resin is meant, and “cyan pigment 2” means the cyan pigment 2 adhered to the polyurethane resin, and in Table 2, “black pigment 3” is the black added with styrene acrylic resin. “Yellow Pigment 3” means a styrene acrylic resin-added yellow pigment 3, “Magenta Pigment 3” means a styrene acrylic resin-added magenta pigment 3, and “Cyan”. “Pigment 3” means styrene acrylic resin-added cyan pigment 3.)

  In each of the inkjet ink compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 8, the image density, storage stability, marker resistance, and scratch resistance were evaluated according to the following evaluation criteria. The results are shown in Table 3 and Table 4.

<Image density evaluation>
Inkjet ink compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 8 were filled in ink cartridges, respectively, and coated cardboard OK with an inkjet printer EM-930C (manufactured by Seiko Epson Corporation). Printing is performed on a ball (made by Oji Paper Co., Ltd.), and the image sample is calculated by measuring the density 20 times with a reflective optical color densitometer (X-Rite Inc. X-Rite 504, sold by Nihon Hakusho Co., Ltd.). The image density was evaluated by evaluating the OD average value according to the following criteria.
"○" evaluation: Black pigment 1.3 or higher
Yellow pigment 1.3 or more
Magenta pigment 1.8 or higher
Cyan pigment 1.9 or more “△” evaluation: Black pigment 1.25 or more and less than 1.3
Yellow pigment 1.25 or more and less than 1.3
Magenta pigment 1.75 or more and less than 1.8
Cyan pigment 1.85 or more and less than 1.9 “x” evaluation: Black pigment less than 1.25
Yellow pigment less than 1.25
Magenta pigment less than 1.75
Cyan pigment less than 1.85

<Storage stability evaluation>
Each ink-jet ink composition adjusted to a pigment concentration of 5.0% by mass is placed in a closed glass bottle and stored in an incubator at 70 ° C. for 4 weeks, and the viscosity (mPa · s) and particle size (nm) before and after the test are stored. Was measured, and storage stability was evaluated according to the following criteria.
○: The change rate of the viscosity (or particle size) is in the range of −5% to + 5% until the lapse of 4 weeks.
(Triangle | delta): The change rate of the viscosity (or particle size) at the time of progress for four weeks is out of the range of -5%-+ 5%, but exists in the range of -10%-+ 10%.
X: The rate of change in viscosity (or particle size) after the lapse of 4 laps is outside the range of -10% to + 10%.

<Marker resistance>
Each ink-jet ink composition adjusted to a pigment concentration of 5.0% by mass is filled in a cartridge, printed on plain paper with an ink-jet printer EM-930C (manufactured by Seiko Epson Corporation), A line was drawn with a line marker pen (PM-L103Y or PM-L103B) manufactured by KOKUYO, and the marker resistance was evaluated according to the following criteria.
○: The printed part is not soiled.
Δ: Slight dirt and blurring are observed around the printed portion and characters.
X: The printed portion is blurred and the portions other than the printed portion are stained.

<Abrasion resistance>
Each ink-jet ink composition adjusted to a concentration of 5.0% by mass is filled in a cartridge, and solid-printed on plain paper with an ink-jet printer EM-930C (manufactured by Seiko Epson Corporation). Scratch 10 times with ADLCC clock meter CM-5 manufactured by SDL ATLAS equipped with cotton cloth (Kanakin 3 for JIS dyeing fastness test, manufactured by Japanese Standards Association) in accordance with JIS L 0803, and evaluated according to the following criteria did.
○: Cotton cloth is not soiled.
Δ: Slightly dirty cotton cloth.
X: Cotton cloth is dirty.

  From Table 3, the ink-jet ink compositions obtained in Examples 1 to 4 are acidic with a specific water-dispersible polyurethane resin (III) having a urea bond in the molecule and a hydroxyl group at the end, respectively. Because it is made of a polyurethane resin-attached pigment that is brought into contact with the group-containing pigment (IV), it exhibits excellent dispersibility, excellent image density, and excellent storage stability. It can be seen that an ink coating film excellent in marker resistance and scratch resistance can be formed.

  On the other hand, from Table 4, the inkjet ink compositions obtained in Comparative Examples 1 to 8 have a water-dispersible polyurethane resin B having a terminal hydroxyl group but no urea bond in the molecule and an acidic group on the surface. Is it made of a polyurethane resin adhesion pigment formed by contacting pigment (IV) (Comparative Examples 1 to 4), or contacting styrene-acrylic resin with pigment (IV) having an acidic group on the surface? Since the styrene-acrylic resin-added pigment is used (Comparative Example 5 to Comparative Example 8), it is inferior in storage stability, marker resistance and scratch resistance (Comparative Example 1 to Comparative Example 1). It can be seen that Example 4) is inferior in image density, storage stability, marker resistance and scratch resistance (Comparative Examples 5 to 8).

  According to the present invention, when used in a pigment dispersion composition, the polyurethane resin can exhibit an excellent image density, dispersibility, and storage stability, and can form an ink coating film with excellent marker resistance and scratch resistance. A pigment dispersion composition and an ink-jet ink composition can be provided while providing an adhesion pigment.

Claims (5)

  A polyisocyanate polyurethane resin (I) having an anionic polar group or a nonionic polar chain and having a terminal isocyanate group is contacted with a primary amine or secondary amine (II) having a hydroxyl group in the molecule. A polyurethane resin-attached pigment obtained by contacting a water-dispersible polyurethane resin (III) having a urea bond and a terminal hydroxyl group with a pigment (IV) having an acidic group on the surface in an aqueous medium.   The polyurethane resin-attached pigment according to claim 1, wherein the pigment (IV) having an acidic group on the surface is a self-dispersing pigment having an acidic group on the surface.   The polyurethane resin-attached pigment according to claim 1, wherein the pigment (IV) having an acidic group on the surface is self-dispersing carbon black having an acidic group on the surface.   A pigment dispersion composition comprising the polyurethane resin-attached pigment according to claim 1.   The inkjet ink composition characterized by including the polyurethane resin adhesion pigment in any one of Claims 1-3.