JP2017031287A - Polymer aqueous dispersion, process for producing the same, aqueous pigment dispersion and ink jet recording ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer water dispersion useful as a coated film forming component achieving high adhesiveness, high stretchability and high durability.SOLUTION: There are provided a polymer water dispersion containing a resin fine particle where a specific urethane polymer (I), a vinyl polymer (II) and an A-B block copolymer (III) with mass ratio of (I):(II):(III) is 10 to 80:10 to 80:10 to 80, where (I) is dispersed in water by having an anionic group, (II) has molecular weight of 50,000 to 400,000 and the copolymer (III) has: an A block composed of methacrylic acid-based monomers which is practically insoluble in water and has molecular weight of 1,000 to 10,000, molecular weight distribution is 1.5 or less; and a B block that contains methacrylic acid as a constituent monomer and has acid value of 50 to 300 mgKOH/g and molecular weight of 1,000 to 10,000 and the polymer (III) has number average molecular weight of 2,000 to 20,000, molecular weight distribution is 1.5 or less and acidic value of 30 to 200 mgKOH/g and a manufacturing method therefor.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous polymer dispersion, a method for producing the same, an aqueous pigment dispersion for inkjet ink, and an inkjet recording ink. A polymer aqueous dispersion that can effectively function as a binder component when contained in an ink used for ink jet printing as a material, a production method thereof, and an aqueous pigment dispersion comprising the polymer aqueous dispersion The present invention relates to a liquid and an ink for inkjet recording.

  Objects to be printed by water-based inkjet printing in recent years are not only paper, but also resin films, textile products, metals, and the like, and their print media are diverse. In particular, in a printed matter recorded on a printing medium other than paper, the printed matter is likely to be peeled off by rubbing or the like, and for the purpose of preventing this (rubbing resistance), A binder component is added as a film forming component. For this binder component, a polymer emulsion having a low aqueous solution viscosity is used, and a polyurethane water dispersion or an acrylic emulsion is used (see Patent Documents 1 to 3, etc.).

Special table 2003-520279 gazette Japanese Patent Laid-Open No. 2004-197090 JP 2005-179679 A International Publication No. WO2012 / 124212

  For example, when a polyurethane water dispersion is used as the binder component constituting the ink, high adhesion of the urethane polymer can be obtained, and in the printed matter, high abrasion resistance and stretchability can be obtained. In the ink discharge during ink jet printing, there is a problem that the continuous discharge stability is poor. The reason seems to be that polyurethane is influenced by the fact that there are few water-soluble groups in its structure. Further, according to the study by the present inventors, once the polyurethane contained in the ink is dried, there is no re-dissolution property, and problems such as clogging of the head may occur. In addition, polyurethane has poor compatibility with the pigment dispersant used in the ink, and there is a problem that the storage stability of the fine dispersion of the pigment is poor.

  In addition, since the acrylic emulsion has high particle stability, when it is used as a binder component constituting an ink, it has good ejection stability and re-dissolvability, and various methods have been proposed. (Patent Document 4). However, there is a problem in that the adhesion of the acrylic polymer is insufficient, and the formed printed matter may have insufficient abrasion resistance and stretchability.

  In view of the above circumstances, an object of the present invention is to provide a resin film formed with high adhesion to a substrate when applied as a binder component to an aqueous liquid composition such as ink for inkjet recording. In addition, the film formed on textiles and the like that shows high stretchability and high durability is excellent with both high adhesion and flexibility, and the addition of a polymer aqueous dispersion preserves ink. An object of the present invention is to provide a useful polymer aqueous dispersion which is not impaired in stability and ejection stability and has high re-solubility when dried. Furthermore, an object of the present invention is to provide a useful aqueous pigment dispersion that exhibits the above-mentioned effects, which is useful in pigment-containing inks, and that improves the abrasion resistance and stretchability of the formed printed matter.

  The above object is achieved by the present invention described below. That is, the present invention is a resin fine particle in which three types of polymers of urethane polymer (I), vinyl polymer (II), and AB block copolymer (III) having a methacrylic acid monomer as a constituent are combined. An aqueous polymer dispersion containing the following three polymer mass ratios (I) :( II) :( III) constituting the composite resin fine particles: 10-80: 10-80: 10-80 The urethane polymer (I) is a urethane polymer having an ionized anionic group in its structure and dispersed in water, and the vinyl polymer (II) is obtained by polymerizing a vinyl monomer. The polystyrene-reduced number average molecular weight in the gel perchromatograph may be 50,000 to 400,000, which may have a cross-linked structure as required. The B block copolymer (III) is composed of 90% by mass or more of a methacrylic acid monomer, the polymer block of A is substantially insoluble in water, its number average molecular weight is 1000 to 10,000, and molecular weight distribution Is 1.5 or less, and the polymer block of B has methacrylic acid as at least a constituent monomer, an acid value of 50 to 300 mgKOH / g, and a number average molecular weight (number average molecular weight of the entire AB block copolymer). The molecular weight obtained by subtracting the number average molecular weight of the polymer block of A from 1000 to 10000, the number average molecular weight of the AB block copolymer is 2000 to 20000, the molecular weight distribution is 1.5 or less, and A polymer aqueous dispersion characterized by having an acid value of 30 to 200 mg KOH / g is provided.

  The following are mentioned as a preferable form of the polymer aqueous dispersion of this invention. That is, the composite resin fine particles have an average particle size of 50 to 200 nm and the particle size distribution is unimodal; the polymer block of A constituting the AB block copolymer (III) The methacrylic acid monomer, which is a forming component of the polymer, contains at least one of benzyl methacrylate or cyclohexyl methacrylate; the urethane polymer (I) contains an isocyanate component, a polyol component and / or a polymer polyol component, and dimethylol. It is a reaction product obtained by reacting an alkanoic acid component with a diamine component as a chain extender as required, and the polymer polyol component is selected from the group consisting of polyether polyol, polycarbonate polyol, polysiloxane polyol and polyvinyl polyol. Want to be selected Re one or more are used, and the acid value of the polymer are mentioned to be 10 to 100 mg / g.

  As another embodiment, the present invention provides the above-described method for producing a polymer aqueous dispersion of the present invention, wherein the urethane polymer dispersed in water by neutralizing the anionic group with water in water ( I) and the AB block copolymer (III) dispersed in water by neutralizing the carboxy group of methacrylic acid constituting the polymer block of B with an alkali. Using the radical polymerization initiator in the presence, the vinyl polymer (II) is obtained by adding and polymerizing the vinyl monomer, and the resin fine particles are formed by combining the three polymers. A method for producing an aqueous polymer dispersion is provided.

  The following are mentioned as a preferable form of the manufacturing method of the polymer aqueous dispersion of this invention. That is, as the urethane polymer (I), an aqueous dispersion in which the anionic group is neutralized with an alkali and dispersed in water, an average particle diameter by light scattering measurement is 10 to 100 nm, and The resin fine particles obtained by complexing the three kinds of polymers have an average particle size of 50 to 200 nm, and the particle size distribution is unimodal; the alkali for neutralizing the anionic group is (meta ) At least one of dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate, neutralizing part or all of the anionic group; constituting the AB block copolymer (III) The methacrylic acid monomer which is a component for forming the polymer block of A is at least one of benzyl methacrylate and cyclohexyl methacrylate Containing; using as AB block copolymer (III) what was obtained using the living radical polymerization which uses a polymerization initiating compound; As said urethane polymer (I), an isocyanate component and a polyol component And / or the polymer polyol component, the dimethylolalkanoic acid component, and optionally the diamine component as a chain extender, the acid value of the polymer is 10 to 100 mg KOH / g, and As the polymer polyol component, use is made of one or more selected from the group consisting of polyether polyol, polycarbonate polyol, polysiloxane polyol and polyvinyl polyol.

  As another embodiment, the present invention includes at least a pigment, a pigment dispersant, an organic solvent, water, and a binder component, and the binder component is any one of the above polymer aqueous dispersions. An aqueous pigment dispersion is provided.

  The following are mentioned as a preferable form of the aqueous pigment dispersion liquid of this invention. That is, the pigment dispersant is the AB block copolymer (III) described above; the organic solvent is diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, At least one selected from the group consisting of propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol and glycerin The mass ratio of the pigment to the polymer in the polymer aqueous dispersion as the binder component is 100 parts by weight of the pigment. Te, it is 50 to 300 parts; include.

  As another embodiment of the present invention, there is provided an ink for ink-jet recording comprising any one of the above polymer aqueous dispersions.

  As another embodiment of the present invention, there is provided an ink for ink-jet recording comprising any one of the above aqueous pigment dispersions.

  According to the present invention, the resin fine particles constituting the polymer aqueous dispersion are divided into three different polymers: a specific urethane polymer (I), a specific vinyl polymer (II), and a specific AB block copolymer (III). By combining them into fine particles (hereinafter also referred to as “polymer composite fine particles” or “composite fine particles”), the individual performances brought about by the properties of the respective polymers can be exhibited without any problems, and synergistic effects can be obtained by these. Therefore, the following great effects that could not be achieved with the prior art are realized.

  Specifically, when the polymer aqueous dispersion of the present invention is used as a binder component, the resin film formed by the urethane polymer (I) has high adhesion to the substrate, high elasticity, and high durability. For example, when used for printing on textiles, etc., the film exhibits good touch and texture, and at the same time has high flexibility and adhesion. It will be shown.

  Furthermore, in addition to these polymers, when the polymer aqueous dispersion of the present invention is used as a binder component by combining a specific AB block copolymer (III) in addition to the above, the following effects can be obtained. can get. Since the polymer block of B constituting the compound has a high acid value, the composite fine particles have a good solubility in water. For example, when used in an aqueous liquid composition such as an ink for ink jet recording, the discharge stability is improved. And storage stability and mechanical stability of the composite fine particles in the aqueous liquid composition can be improved. Furthermore, the water affinity of the composite fine particles themselves can be increased, and as a result, even when the aqueous liquid composition is dried, it is easily redissolved and becomes a pigment dispersion again, thereby exhibiting the effect of resolubility.

  Furthermore, in a preferred embodiment of the present invention, for example, in the case of an aqueous pigment dispersion containing a pigment, a pigment dispersant, an organic solvent, water, and a binder component used in an inkjet recording ink, the polymer composite fine particles are used as a binder component. At the same time, the AB block copolymer (III) constituting the polymer aqueous dispersion of the present invention is used as a pigment dispersant for dispersing the pigment. By comprising in this way, the compatibility of the polymer water dispersion and the dispersed pigment particles can be improved, and the aggregation of the pigment and polymer, which causes the storage stability of the aqueous pigment dispersion, is hindered. The occurrence of precipitation and the like can be effectively suppressed. As a result, according to the present invention, high storage stability is achieved in the aqueous pigment dispersion and the pigment ink using the same. Note that the use of the AB block copolymer (III) as a pigment dispersant has an advantage that the addition of the polymer composite fine particles to the aqueous pigment dispersion does not hinder the dispersibility of the pigment.

  In addition, AB block copolymer (III) which comprises this invention can be reliably made into the thing of the desired structure according to a design by carrying out the living radical polymerization of a specific monomer on specific conditions. Here, the living radical polymerization is capable of polymerizing a vinyl monomer having an acidic group or an amino group. As will be described later, the living radical polymerization method particularly used in the present invention is an easy polymerization method that does not require a special material and can be performed simply by adding a polymerization initiating compound and a catalyst to conventional radical polymerization. Since no special manufacturing equipment or purification of materials is required, there is an advantage that it is advantageous in terms of cost and friendly to the environment, and this point is also a great effect of the present invention.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention. First, in the present invention, resin fine particles formed from three different types of polymers that characterize the present invention are defined as “resin fine particles formed by combining three different types of polymers”. The reason is that, as will be described later, the polymer aqueous dispersion of the present invention is not a mixture of three types of polymers, but a single particle size distribution (“unimodal”) consisting of three types of polymers formed by a polymerization reaction. This is because it was an aqueous dispersion composed of a polymer exhibiting the following, and it could not be precisely defined other than expressing “composite”. That is, as defined in the production method, the polymer aqueous dispersion of the present invention is a vinyl-based polymer in the presence of an aqueous dispersion of urethane polymer (I) and an aqueous dispersion of AB block copolymer (III). Monomer is added and emulsion polymerized to form a vinyl polymer (II), and it is clear that each polymer particle is not individually present, and further, from the behavior of the formed particle, This is because the vinyl polymer (II) is the shell and the other polymer is not the core. According to the study by the present inventors, the composite fine particles characterizing the present invention include an AB block copolymer (III) including a urethane polymer (I) and a vinyl polymer (II) formed by emulsion polymerization. It is thought that the particles are like that.

  As a result of intensive studies on the above-described problems of the prior art, the inventors have obtained composite fine particles obtained by combining three types of polymers: a specific urethane polymer, a specific vinyl polymer, and a specific AB block copolymer. It has been found that an aqueous polymer dispersion comprising the above is extremely useful as a binder component in an aqueous liquid composition such as an ink for ink jet recording, and has achieved the present invention. That is, by using the composite fine particles having the above structure as a binder component, the ink is clearly superior in ejection stability and re-dissolvability as compared with ink containing conventional resin fine particles, and the printed matter formed is Excellent physical properties such as adhesion, abrasion resistance and high stretchability. Furthermore, according to the polymer aqueous dispersion of the present invention, when this is added to an aqueous pigment dispersion or an ink for inkjet recording, the AB block copolymer (III) constituting the present invention is used as a pigment dispersant. Thus, since the compatibility between the pigment dispersant and the composite fine particles is excellent, it is possible to realize high storage stability without aggregation of the resin fine particles and the pigment.

  The feature of the polymer aqueous dispersion of the present invention capable of realizing the above-mentioned remarkable effect is that the dispersed resin particles are composed of urethane polymer (I), vinyl polymer (II), and methacrylic acid monomer The composite contains fine particles in which three different polymers of the AB block copolymer (III) are combined, and the combined three types of polymers (I) :( II) :( III) have a mass ratio of 10 to 80:10 to 80:10 to 80. Hereinafter, each of these three types of polymers will be described.

[Urethane polymer (I)]
First, the urethane polymer (I) which is the first polymer component constituting the polymer composite fine particles characterizing the present invention will be described. Among the remarkable effects achieved by the present invention, the urethane polymer (I) has high durability such as high adhesion to a substrate, high stretchability, and abrasion resistance, particularly in the formed resin film. It is an important polymer component for realizing. The above effect is considered to be obtained by the high agglomeration property of the urethane polymer (I) by the hydrogen bond of the urethane bond and the physical bond of the soft segment and the hard segment.

  The urethane polymer (I) constituting the polymer aqueous dispersion of the present invention is not particularly limited as long as it has an ionized anionic group in its structure and is dispersed in water. When forming the urethane polymer (I), a compound having an anionic group is used as a monomer component. By neutralizing the anionic group with an alkali, the urethane polymer (I) can be dispersed in water in the form of fine particles, which is also referred to as a urethane dispersion. The anionic group is not particularly limited, and examples thereof include a carboxy group, a sulfonic acid group, and a phosphoric acid group. In particular, the compounds having a carboxy group are preferred among the above-mentioned because of the water resistance of the film and the availability of raw materials.

  The compound having a carboxy group used as a suitable monomer component when producing the urethane polymer (I) may be any compound having a hydroxyl group capable of urethane bonding, and examples thereof include hydroxyalkanecarboxylic acids. According to the study by the present inventors, among them, dimethylolalkanoic acid is preferable. Examples of dimethylolalkanoic acid include α, α-dimethylolpropanoic acid, α, α-dimethylolbutanoic acid, α, α-dimethylolpropionic acid, α, α-dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, and And dihydroxybenzoic acid. Particularly preferable are α, α-dimethylolpropanoic acid and α, α-dimethylolbutanoic acid, which are easily available.

  The amount of these dimethylolalkanoic acids introduced when the urethane polymer (I) is produced is determined from the viewpoints of water dispersibility of the urethane polymer, water resistance, and the average particle size obtained thereby. Preferably, the acid value of the urethane polymer (I) by introducing the dimethylolalkanoic acid is preferably 10 to 100 mgKOH / g. If it is less than 10 mg KOH / g, the dispersed particle diameter of the resulting urethane polymer (I) becomes larger than the average particle diameter range of 100 nm which is preferably used in the present invention, which may cause clogging of the inkjet head. It is not preferable. On the other hand, if it is greater than 100 mgKOH / g, the urethane polymer (I) may not dissolve in water but dissolve in water, or the water resistance of the urethane polymer (I) itself may deteriorate. More preferably, it is 20-80 mg / KOH. The acid value is mg of potassium hydroxide necessary to neutralize 1 g of the resin. For measurement, a resin dissolved in an organic solvent (for example, toluene / ethanol = 70/30 mass ratio) is 0 Perform titration with 1N potassium hydroxide as titrant and phenolphthalein as indicator. In this invention, the value measured in this way is used for an acid value.

  The urethane polymer (I) constituting the present invention more specifically includes an isocyanate component, a polyol component and / or a polymer polyol component, and a dimethylolalkanoic acid component that imparts an acidic group as described above, It is preferable to use a diamine component as a chain extender as necessary and to react these components. As described above, the urethane polymer (I) is a polymer obtained from a conventionally known material, and these components will be described below.

  Examples of the isocyanate component include various diisocyanate compounds such as toluene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate. These allophanate-bonded and burette-bonded polyisocyanate compounds can also be used, and are not particularly limited. From the viewpoint of suppressing yellowing, aliphatic and alicyclic diisocyanate compounds are preferred.

  As the polyol component, diol compounds such as ethylene glycol, propylene glycol, 1,4 butanediol and neopentyl glycol, and polyols having three or more hydroxyl groups such as glycerin can be used, and are not particularly limited.

  Examples of the polymer polyol component include polymer diols in which hydroxyl groups are bonded to both ends of a polymer structure such as polyester, polyether, polycarbonate, polyvinyl, and polysiloxane. However, in the case of polyester, when the ester group in the structure is an aqueous pigment dispersion or aqueous inkjet recording ink and the pH of the aqueous solution is alkaline, the ester group of the polyester diol can be stored for a long time or added. Since it hydrolyzes when it preserve | saves and warms and there exists a possibility that the polymer physical property of urethane polymer (I) may change, it is not so preferable. Therefore, in this invention, it is preferable to use polyether polyol, polycarbonate polyol, polyvinyl polyol, and polysiloxane polyol.

  Although it will not specifically limit if it is an above-mentioned polymer polyol, For example, Polyether glycol, such as polyethyleneglycol, a polyprolene glycol, polytetramethylene glycol; Carbonate diols, such as polybisphenol A carbonate diol and polyhexamethylene carbonate diol; Examples thereof include polyvinyl diols such as polyvinyl ethyl ether diol and polystyrene diol; and polysiloxane polyols such as polydimethylsiloxane diol and polyphenylmethylsiloxane diol. These molecular weights are not particularly limited, but it is preferable that the average molecular weight determined by hydroxyl value determination of the terminal group is 500 to 3000. If it exceeds 3000, the properties of the polymer polyol become too strong, the cohesiveness of the urethane bond cannot be exhibited, and the durability may deteriorate.

  In the preparation of the urethane polymer (I), a diamine component can be used as a chain extender, if necessary. The diamine component is prepared by synthesizing an isocyanate-terminated urethane prepolymer with the above-mentioned isocyanate component, polyol component, polymer polyol component, and dimethylolalkanoic acid component, and neutralizing the carboxy group with an alkali to form a urethane water dispersion. While neutralizing, a diamine component is added to form a urea bond between the isocyanate of the urethane prepolymer and the amino group of the diamine, thereby extending the chain. Although it does not specifically limit as a compound, For example, a hydrazine, ethylenediamine, hexamethylenediamine, isophoronediamine etc. will be mentioned. Also, polymer diamines such as polyethylene glycol diamine can be used. Although this polymer diamine may be used as a chain extender, there is no problem even if it is used in the synthesis of a urethane prepolymer.

  The alkali necessary for neutralizing the carboxy group in the urethane polymer (I) is not particularly limited, and ammonia; organic amines such as trimethylamine, dimethylaminoethanol, triethylamine, diethanolmethylamine, triethanolamine; Alkali metal hydroxides such as lithium, sodium hydroxide, and potassium hydroxide are listed, and one or more of these are used. More preferably, the organic amine is neutralized by using a vinyl monomer having an amino group such as dimethylaminoethyl (meth) acrylate or diethylaminoethyl (meth) acrylate as part or all of the alkali. It is good.

  This is because, in the method of obtaining composite fine particles characterizing the present invention, when the vinyl polymer (II) is formed, a vinyl monomer is added and polymerized in the presence of another polymer to form a composite. It depends on consideration. That is, the vinyl group which is an addition polymerizable group of the vinyl monomer having an amino group used when neutralizing an anionic group such as a carboxy group of the urethane polymer (I) is By addition polymerization, the polymer is polymerized, whereby the urethane polymer (I) and the vinyl polymer (II) are combined more reliably and satisfactorily.

  As other materials, if necessary, when an isocyanate remains at the terminal, a lower alcohol, a lower amine, or the like may be used to extinguish the isocyanate.

  The urethane polymer (I) constituting the present invention can be obtained by a conventionally known method and is not particularly limited. Illustratively, as described above, a urethane prepolymer of a terminal isocyanate is obtained in an organic solvent having an isocyanate component, a diol component, and a compound having an anionic group, if necessary, in an organic solvent that does not have a group that reacts with isocyanate. The conditions and reaction ratio are arbitrary, the reaction temperature is 20 ° C. to 150 ° C., and a catalyst such as tin octylate or diazabicycloundecene may be used. Let After adding alkali to the obtained urethane prepolymer, water is added or an aqueous alkali solution dissolved in water is added, and the chain is extended with a diamine compound as necessary to constitute the present invention. An aqueous dispersion of urethane polymer (I) is obtained. The number average molecular weight of the urethane polymer (I) thus obtained is not particularly limited, and is preferably 10,000 to 100,000 because durability such as abrasion resistance can be imparted. The number average molecular weight referred to in the present invention refers to the number average molecular weight in terms of polystyrene in the measurement by gel permeation chromatography (hereinafter referred to as GPC), and the same applies hereinafter including Examples.

  The urethane polymer (I) constituting the present invention is dispersed in water, and a dispersion dispersed in water is used at the time of compounding. When the urethane polymer (I) is obtained as an aqueous dispersion, In particular, it is not necessary to use an organic solvent. On the other hand, when using, it is preferable to use the organic solvent which does not have a group, a hydroxyl group, an amino group, a thiol etc. which have high reactivity with an isocyanate group. Specifically, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, hydrocarbon solvents such as toluene, ether solvents such as tetrahydrofuran and ethylene glycol dimethyl ether, and glycol solvents such as propylene glycol monomethyl ether acetate A solvent, an amide solvent such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, or the like may be used. The aqueous dispersion of urethane polymer (I) used in the composite of three different polymers may contain these solvents. However, according to the study by the present inventors, the presence of a solvent when the above-mentioned vinyl monomer (II) constituting the present invention is obtained by polymerization of the added vinyl monomer in water as described above is combined. In some cases, the added vinyl monomer is dissolved in an aqueous solvent and composite fine particles cannot be obtained successfully. Therefore, it is preferable to remove the solvent. Moreover, even if it contains the organic solvent, it is preferable that it is less than 2%. From these viewpoints, the organic solvent used above is preferably a low-boiling solvent having a boiling point of 100 ° C. or lower that is easy to remove the solvent.

  When preparing the polymer aqueous dispersion of the present invention, an aqueous dispersion of the urethane polymer (I) obtained by the above-mentioned materials and methods, wherein the anionic group is neutralized with an alkali and dispersed in water. Although used, the average particle diameter in the light scattering measurement is more preferably 10 to 100 nm. The reason why the average particle size is preferably in the above range is that the composite fine particles constituting the polymer aqueous dispersion of the present invention preferably have an average particle size of 50 to 200 nm. That is, the average particle size of the aqueous dispersion of urethane polymer (I) used for the production of the composite fine particles is set so that the particle size of the composite fine particles is within this range. If it is smaller than 10 nm, the viscosity may be high or the complexing characterizing the present invention may not be successful. If it exceeds 100 nm, the average particle diameter of the composite fine particles of the present invention becomes too large, and the polymer of the present invention When an aqueous dispersion is used as a binder component of the ink, it is not preferable because the head may be clogged or the filterability of the ink may be deteriorated. Preferably it is 20-120 nm.

  The light scattering measurement used for the particle diameter measurement above is a method called dynamic light scattering method, and irradiates the particle with monochromatic light, and detects and analyzes the scattered light coming out of the particle, In this method, the diffusion coefficient of particles can be obtained, and the average particle diameter can be measured from the diffusion coefficient. The average particle diameter of the particles constituting the dispersion defined in the present invention is the number average particle diameter measured by this method. The measuring device and method are not particularly limited.

[Vinyl polymer (II)]
Next, the vinyl polymer (II) which is the second component constituting the polymer composite fine particles characterizing the present invention will be described. The vinyl polymer increases the durability of the formed film such as adhesion, tackiness, and abrasion resistance when the polymer aqueous dispersion of the present invention is used as a binder component, and the polymer water of the present invention. When the dispersion is used for printing, it is an important polymer component for improving the feel and texture of the formed film.

  The vinyl polymer (II) will be described in detail later. In the presence of the aqueous dispersion of the urethane polymer (I) described above and the aqueous dispersion of the AB block copolymer (III), a radical initiator is used. It is a polymer component obtained by using and polymerizing by adding a vinyl monomer. This is so-called emulsion polymerization. In the emulsion polymerization, the details of the mechanism by which the three polymers are combined are unclear, but from the characteristics of the resulting fine particles, the AB block copolymer (III) is converted into the urethane polymer (I), It is considered that the particles include the vinyl polymer (II) formed by the emulsion polymerization. Since it is emulsion polymerization, the molecular weight of the vinyl polymer (II) to be formed is as large as 50,000 to 400,000 as the number average molecular weight is defined in the present invention. It greatly contributes.

  The vinyl monomer used is not particularly limited, and examples thereof include addition-polymerizable vinyl monomers capable of radical polymerization, and are not particularly limited. Examples include aromatic, heterocyclic vinyl monomers such as styrene, vinyl toluene, vinyl naphthalene, vinyl benzoic acid and its lower alcohol ester, vinyl carbazole, styrene sulfonic acid and its lower alcohol ester, N-vinyl pyridine; vinyl acetate, propion Aliphatic, alicyclic and aromatic carboxylic acid vinyl ester monomers such as vinyl acid vinyl, cyclohexane carboxylic acid vinyl and vinyl benzoate;

  (Meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, Hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, tridecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate , Trimethylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecyl (meth) acrylate, adamantyl (meth) acrylate, benzyl (meth) acrylate, ( Meth) acrylic acid phenoxyethyl,

  2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, tetrahydro (meth) acrylate Furfuryl, glycidyl (meth) acrylate, phenyl (meth) acrylate, naphthyl (meth) acrylate, dimethylaminoethyl (meth) acrylate and monomers quaternized with methyl chloride or benzyl chloride, (meth) Diethylaminoethyl acrylate and monomers quaternized with methyl chloride or benzyl chloride, t-butylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, ( (Meth) acrylic acid poly (n = 2 or more) Tylene glycol, (meth) acrylic acid poly (n = 2 or more) propylene glycol, (meth) acrylic acid poly (n = 2 or more) ethylene glycol monomethyl ether, (meth) acrylic acid cyclopentenyloxyethyl, (meth) acryloyl Roxyethyl isocyanate, 2- (2′-hydroxy-5- (meth) acryloyloxyethylphenyl) -2H-benzotriazole (effective for improving light resistance), tetramethyl (meth) acrylate Peridinyl, (meth) acrylic acid pentamethylpiperidinyl, (meth) acrylic acid hydroxyethyl monomer and polybasic acid such as phthalic acid, succinic acid, maleic acid, trimellitic acid and lower alcohol ester thereof, Such as (meth) acryloyloxyethyl phosphate ) Acrylic acid polymer;

  Amide monomers such as (meth) acrylamide, dimethyl (meth) acrylamide, (meth) acryloylmorpholine, N-methylol (meth) acrylamide; (meth) acrylonitrile; N-vinylpyrrolidone; maleic anhydride, maleic acid and mono thereof, Dibasic alcohol ester, N-phenylmaleimide, N-cyclohexylmaleimide, itaconic anhydride, itaconic acid and its mono- and dibasic vinyl ester monomers such as di-lower alcohol ester, etc. are used, and one or more types are used and particularly limited. However, it is selected according to the required properties and effects.

  Further, if necessary, not only a monofunctional vinyl monomer but also a polyfunctional vinyl monomer having a large number of addition polymerizable groups can be used as it is or in combination with the above-described monomers. Since it is polyfunctional, it is considered that the vinyl polymer (II) has a crosslinked structure by using these, and the durability of the film formed thereby is improved. Although it does not specifically limit as this polyfunctional vinyl-type monomer, For example, divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, butylene glycol di (meta) ) Acrylate, hexanediol di (meth) acrylate, methacryloyloxyethyl acrylate, allyl (meth) acrylate, vinyloxyethoxyethyl (meth) acrylate, di (meth) acrylate of bisphenol A alkylene oxide adduct, trimethylol Propane tri (meth) acrylate, glyceryl tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, poly Terujioru and polycarbonate diol (meth) acrylic acid ester. The amount when such a polyfunctional monomer is appropriately used is not particularly limited, but is 5% or less, more preferably 3% or less based on the monofunctional monomer. This is because if the crosslinking component is too much, the polymer composite particles may not form a film.

  Furthermore, a macromonomer having an addition polymerizable group at one end of the polymer can be used, and the macromonomer is not limited. Examples include (meth) acryloyl polystyrene, (meth) acryloyl polymethyl methacrylate, (meth) acryloyl polydimethylsiloxane, and the like. By using such a macromonomer, the structure of the vinyl polymer can be a graft structure.

  The vinyl-based polymer (II) formed with the above-mentioned monomers as a constituent component exerts effects such as durability and texture on the formed film, so that the number average molecular weight in terms of polystyrene in the gel perchromatograph is 50,000- It needs to be 400,000. Moreover, you may have a crosslinked structure as needed. If the number average molecular weight is less than 50000, the expected durability may not be obtained, and if it exceeds 400000, it may not be successfully combined. More preferably, it is 70000-200000. Moreover, when a polyfunctional vinyl monomer as described above is used, a crosslinked structure can be taken. The vinyl polymer is cross-linked and takes a three-dimensional network cross-linked structure, so that it becomes insoluble in the solvent. That is, when a film is formed by coating, improvement in solvent resistance and water resistance can be expected. In addition, the detail of the polymerization method of vinyl-type polymer (II) which comprises this invention is mentioned later.

[AB block copolymer (III)]
Next, the AB block copolymer (III), which is the third component constituting the polymer composite fine particles characterizing the present invention, and more specifically, the AB block copolymer (III) comprising a methacrylic acid monomer as a constituent component. Will be described. The AB block copolymer (III) is an important polymer component in the present invention for exhibiting effects such as aqueous dispersion stability, re-dissolvability, and ejection stability of the composite fine particles. More specifically, the AB block copolymer (III) is composed of 90% by mass or more of a methacrylic acid monomer, the polymer block of A is substantially insoluble in water, and the number average molecular weight is 1000 to 10,000. The molecular weight distribution is 1.5 or less, the polymer block of B has methacrylic acid as at least a constituent monomer, the acid value of the polymer block of B is 50 to 300 mgKOH / g, and the molecular weight (A− The molecular weight obtained by subtracting the number average molecular weight of the polymer block of A from the number average molecular weight of the entire B block copolymer is 1000 to 10,000, the number average molecular weight of the AB block copolymer is 2000 to 20000, and the molecular weight distribution is 1 0.5 or less, and the acid value is required to be 30 to 200 mgKOH / g.

  That is, the AB block copolymer (III) constituting the present invention comprises a polymer block of A and a polymer block of B, and the polymer block of A is a hydrophobic polymer block that is substantially insoluble in water, The polymer of B has a structure of a hydrophilic polymer block which has a carboxy group and the carboxy group is neutralized with an alkali and dissolved in water. Since the polymer block of A is substantially insoluble in water, it precipitates when added to water, but the polymer block of B is a polymer block that dissolves in water when its carboxy group is neutralized with an alkali. A polymer block substantially insoluble in water can be dispersed in the fine particles. It is considered that the hydrophobic polymer block of A acts on the urethane polymer (I) and the vinyl polymer (II), and has a function of combining the two polymer particles. Further, since the hydrophilic polymer block of B chain constituting the AB block copolymer (III) is a polymer block dissolved in water, when the above-mentioned hydrophobic polymer part is complexed into complex fine particles, Water soluble chains will be present on the particle surface. With such a structure, it is considered that the composite fine particles can be stably present in water due to steric hindrance or electrical repulsion. In addition, since it is a polymer that dissolves in water, it is considered that even when the fine particles are dried, the effect of giving re-solubility by dissolving and dispersing by adding water again is considered.

  The constitution of the AB block copolymer (III) constituting the present invention will be described, and it is necessary to satisfy all the following requirements. First, 90% by mass or more thereof is composed of a methacrylic acid monomer. The polymer block A is a hydrophobic polymer block that is substantially insoluble in water, has a number average molecular weight of 1,000 to 10,000, and has a molecular weight distribution of 1.5 or less. Furthermore, the polymer block of B has methacrylic acid as at least a constituent monomer, an acid value of 50 to 300 mgKOH / g, and a molecular weight (from the number average molecular weight of the entire AB block copolymer, The molecular weight obtained by subtracting the number average molecular weight, the same shall apply hereinafter) is 1000 to 10,000. Further, it is necessary that the AB block copolymer has a number average molecular weight of 2000 to 20000, a molecular weight distribution of 1.5 or less, and an acid value of 30 to 200 mgKOH / g.

  The polymer block of A is a polymer block that is substantially insoluble in water, and conventionally known methacrylic acid monomers such as those listed below are used for its formation and are designed not to dissolve in water. Examples of the monomer used for synthesizing the A polymer block include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, 2-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate. , Methacrylate esters of aliphatic alcohols such as n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, decyl methacrylate, isodecyl methacrylate, dodecyl methacrylate, octadecyl methacrylate; cyclohexyl methacrylate, methacrylic acid 3 -Methylcyclohexyl, 3-ethylcyclohexyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, 4-t-butylcyclohexyl methacrylate, tricyclomethacrylate Sil, methacrylates of alicyclic alcohols such as dicyclopentenyloxyethyl methacrylate, isobornyl methacrylate, adamantyl methacrylate or alkoxyalkanols thereof; phenyl methacrylate, naphthyl methacrylate, phenoxyethyl methacrylate, benzyl methacrylate, methacrylic acid An aromatic group-containing methacrylate ester such as paracumylphenoxyethyl acid may be mentioned.

  In addition, as a methacrylate containing an aromatic group, 2- (4-benzoxy-3-hydroxyphenoxy) ethyl methacrylate, 2- (2′-hydroxy-5-methacryloyloxyethylphenyl) -2H—having ultraviolet absorption ability And methacrylate esters such as benzotriazole. By using such a monomer, the formed film can be provided with an ultraviolet absorbing ability, and the light resistance of the dye or pigment used in combination can be improved.

  In addition, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, methoxyethoxyethyl methacrylate, poly (n = 2 or more) ) Glycol-based methacrylate esters such as ethylene glycol monomethacrylate, methoxypoly (n = 2 or more) ethylene glycol methacrylate, glyceryl methacrylate; N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N methacrylate -Amino such as t-butylaminoethyl, trimethylaminoethyl chloride methacrylate, tetramethylpiperidinyl methacrylate, pentamethylpiperidinyl methacrylate Or quaternary ammonium base-containing methacrylate; cyclic ether group-containing methacrylate such as tetrahydrofurfuryl methacrylate; 2,2,2-trifluoroethyl methacrylate, 1-chloro-2-hydroxypropyl methacrylate, heptadecafluoromethacrylate Methacrylate esters of halogen-containing alcohols such as decyl; methacrylate esters of silicon atom-containing alcohols such as trimethylsilyl methacrylate and (poly) dimethylsilicone methacrylate can also be used.

  The AB block copolymer (III) constituting the present invention is neutralized with an alkali to make the B polymer block water-soluble, and the A polymer block needs to be substantially insoluble in water. . When synthesizing the A polymer block, a methacrylate having a carboxy group or a phosphate group may be used to such an extent that the polymer block of A is not substantially soluble in water even when neutralized with this alkali. . As the monomer having a carboxy group, methacrylate, methacryloyloxyethyl phosphate, or the like obtained by reacting methacrylic acid or 2-hydroxyethyl methacrylate with a dibasic acid such as succinic acid, maleic acid, or phthalic acid can be used. In order to make the polymer block of A substantially insoluble in water, it is not limited by other monomer components, but the acid value is preferably 0 to 30 mgKOH / g, more preferably 0 to 10 mgKOH / g.

  In addition, since the polymer block of B of the AB block copolymer (III) has a carboxy group, the polymer block of A has a functional group that reacts with the carboxy group, such as a glycidyl group, an isocyanate group, It is preferable not to contain an oxetanyl group. This is because these functional groups may react with the carboxy group and cause gelation.

  When designing the polymer block of A, the type and composition amount are adjusted so that the monomer selected from the compounds listed above is a constituent component and is substantially insoluble in water. Further, since the polymer block of A needs to include and contain other polymer components when obtaining composite fine particles, more preferably, the monomer described above is used to express the high hydrophobicity of the polymer block of A. Among these, it is preferable to use a methacrylate having an aromatic group or an alicyclic group. Aromatic rings are considered suitable because of their benzene nuclei, and alicyclic rings are highly hydrophobic and hard. Particularly preferably, one or more monomers of benzyl methacrylate and cyclohexyl methacrylate are used as a constituent. Since benzyl methacrylate and cyclohexyl methacrylate are highly versatile and the homopolymer has a glass transition temperature of 100 ° C. or less, film formation may be good. These monomers preferably constitute 50% or more of the polymer block of A.

  In the present invention, the polymer block A is substantially insoluble in water, has a number average molecular weight of 1,000 to 10,000, and requires a PDI indicating a distribution of the molecular weight of 1.5 or less. The When the molecular weight is less than 1000, the molecular weight is too small to dissolve in water, and good fine particles cannot be formed. When the molecular weight is greater than 10,000, the AB block copolymer is dispersed in water. , Only the polymer block of A results in a large particle size and may not be able to sufficiently incorporate other polymer components. More preferably, the number average molecular weight of the polymer block of A is 3000 to 8000.

  The PDI representing the molecular weight distribution of the polymer block of A needs to be 1.5 or less. If this PDI is 1.5 or more, a polymer having a molecular weight outside the range of the number average molecular weight described above may be contained in a large amount, and the above-described problems may occur. The PDI of the polymer block of A is more preferably 1.3 or less.

  Next, the B polymer block of the AB block copolymer (III) constituting the present invention will be described. The polymer block of B serves as a polymer block that dissolves in the water of the AB block copolymer. When the polymer block of A is microparticulated or when other polymers are incorporated into composite microparticles, Increases affinity and contributes to dispersion and emulsification stability. In order to obtain this water solubility, a carboxy group is essential for the polymer block of B, and methacrylic acid is an essential component as a monomer component. In order to increase the affinity for water, it is considered that the ester type methacrylate having the carboxy group as described above may be used. However, in these ester types, the ester is hydrolyzed and the water is lost. This is not preferable because the affinity may be impaired. In the present invention, it is specified that methacrylic acid is a constituent component, but the carboxy group contained in the methacrylic acid is neutralized with an alkali and ionized to become water-soluble. In the present invention, the amount of methacrylic acid is defined by the acid value, and specifically, the acid value is required to be 50 to 300 mgKOH / g. If it is less than 50 mgKOH / g, sufficient water solubility cannot be obtained, and if it is greater than 300 mgKOH / g, it has a high affinity for water. Problems may occur. More preferably, it is 70-250 mgKOH / g. Another methacrylate monomer is adjusted as a constituent component so as to have an acid value derived from methacrylic acid. This monomer is not limited, and one or more of the above-mentioned methacrylate monomers are used.

  According to the study by the present inventors, even when the polymer block of B is within the above acid value range, the solubility of B polymer block in water may be insufficient depending on other monomers used. . In that case, when manufacturing the polymer block of B, in addition to methacrylic acid, you may use the other monomer which can be made into the thing with high affinity to the water which dissolves the polymer block of B in water. This monomer may be a monomer having no acidic group and having a hydroxyl group or a polyalkylene glycol chain. Specifically, 2-hydroxyethyl methacrylate, poly (n = 2 or more) ethylene glycol monomethacrylate, poly (methacrylate) (n = 2 or more) ethylene glycol monomethyl ether, poly (methacrylate) (n = 2 or more) ethylene glycol mono 1 or more types, such as ethyl ether, are mentioned. The type is not particularly limited. However, if the amount used is large, when the composite fine particles used as the binder component become a film, the water resistance may deteriorate. For this reason, it is good to use within 50% or less of the monomer which comprises the polymer block of B.

  The molecular weight of the B polymer block is defined by a value obtained by subtracting the number average molecular weight of the A polymer block from the number average molecular weight of the entire AB block copolymer. Since the suitable number average molecular weight of the AB block copolymer used in the present invention is 2000 to 20000 and the number average molecular weight of the polymer block of A is 1000 to 10,000, in the present invention, the number of polymer blocks of B is The average molecular weight was defined as 1000 to 10,000. More preferably, it is 2000-8000.

  The AB block copolymer (III) used in the present invention composed of the above-described polymer block A and polymer block B has a number average molecular weight of 2000 to 20000 and an overall PDI of 1 .5 or less. According to the study by the present inventors, when the number average molecular weight is less than 2000, an aqueous dispersion of composite fine particles in which the urethane polymer (I), the vinyl polymer (II), and the AB block copolymer (III) are combined. Is used as a binder component to form a film, the polymer has a low molecular weight, so the strength is poor and the film performance may be poor. On the other hand, if it is 20000 or more, the molecular weight is too large, and when an aqueous dispersion of composite fine particles is used for, for example, an ink for ink jet recording, the viscosity of the ink becomes high or the molecular weight is too large. The number of molecules decreases, the amount acting on dispersion and emulsification is insufficient, and dispersion and emulsification cannot be performed well. The number average molecular weight of the AB block copolymer (III) constituting the present invention is more preferably 3000 to 15000.

  Further, the PDI of the AB block copolymer (III) constituting the present invention is required to be 1.5 or less. As described above, PDI is necessary for maintaining the limited molecular weight range as much as possible, and can form more stable emulsion particles because the molecular weight is uniform. More preferably, it is 1.4 or less.

  Since the molecular weight range and the acid value range of the polymer block of B were defined, the acid value of the AB block copolymer (III) constituting the present invention was determined to be 30 to 200 mgKOH / g. According to the study by the present inventors, if the particle size is less than 30 mgKOH / g, the stability of the composite fine particles may be insufficient, and if it exceeds 200 mgKOH / g, the water resistance of the coating film of the composite fine particles may be deteriorated. Preferably, it is 50-120 mgKOH / g.

[Composite fine particles]
Next, composite fine particles characterizing the present invention formed by combining three different polymers of the above-mentioned specific urethane polymer (I), specific vinyl polymer (II), and specific AB block copolymer (III) Will be described. The composite fine particles are composed of the above-mentioned polyurethane copolymer (I), vinyl polymer (II), and AB block copolymer (III) in a mass ratio of (I) :( II) :( III) of 10 to 80:10. It is comprised so that it may become ~ 80: 10-80. According to the study of the present inventors, as described above, by forming a composite of three different polymers with the above-mentioned composition ratio defined in the present invention, it is required for the formed film, which is the effect of the present invention. Excellent adhesion, coating durability, water resistance, and stretchability are realized, and when applied as a binder component to an aqueous liquid composition such as ink, the dispersion stability and mechanical stability of composite fine particles, ejection Various effects such as stability and re-solubility are exhibited.

  The mass of each of the above-described polymers may be selected and designed within the above-described range, for example, corresponding to the printing application in the ink for inkjet recording using the polymer aqueous dispersion of the present invention as a binder component. . For example, the urethane polymer (I) should be rich when high film adhesion is required, and the vinyl polymer (II) should be rich when it is necessary to give the fabric a texture by printing. In order to further improve the stability and ejection stability of the composite fine particles in the ink, the AB block copolymer (III) may be made rich. This means that the desired performance can be obtained by making the composite fine particles rich in any of the polymers, and the mass ratio can be designed appropriately. It is also one of the features of the present invention that the configuration can be realized. Hereinafter, the mass ratio of each polymer constituting the composite fine particles will be described.

  The urethane polymer (I) exhibits effects such as adhesion to the substrate and durability of the coating, but is contained in an amount of 10 to 80% by mass in the composite fine particles. If the content is less than 10% by mass, the properties of this urethane polymer cannot be exhibited. Therefore, the properties and effects of the vinyl polymer (II) and the AB block copolymer (III) may not be exhibited. More preferably, it is 10 to 70% by mass, more preferably 20 to 60% by mass in order to exhibit the performance of the urethane polymer (II) and the performance of other polymer components.

  The vinyl polymer (II) is contained in the composite fine particles at a composition ratio of 10 to 80% by mass. If it is less than 10% by mass, the properties of this vinyl polymer will not be exhibited, and if it is more than 80% by mass, other polymers will be relatively less and the urethane polymer (I) and AB used together. The properties of the block copolymer (III) may not be exhibited. More preferably, it is 10 to 70% by mass, more preferably 20 to 60% by mass in order to exhibit the performance of the urethane polymer (II) and the performance of other polymer components.

  The AB block copolymer (III) is contained in the composite fine particles at a composition ratio of 10 to 80% by mass. If the amount is less than 10% by mass, the stability of the composite fine particles in the ink or the ejection stability may be deteriorated. If the amount is more than 80% by mass, the other polymer used in combination becomes too small, and urethane. In some cases, the properties of the polymer (I) and the vinyl polymer (II) cannot be exhibited. Moreover, since it has the block which melt | dissolves in water, the water resistance of the film formed with composite fine particles may worsen. More preferably, the AB block copolymer (III) is 10 to 70% by mass, more preferably 20 to 60% by mass, in order to exhibit the performance of other polymer components. The composite fine particles characterizing the present invention are composed of three different polymers having the above-described composition ratio.

  The average particle size of the composite fine particles characterizing the present invention is preferably 50 to 200 nm. As described above, the urethane polymer (I) preferably used has an average particle diameter of 10 to 100 nm, and the urethane polymer (I) aqueous dispersion and the AB block copolymer (III) aqueous dispersion are Since the vinyl polymer (II) is formed by adding and polymerizing a vinyl monomer in the existing water, the particle size is larger than the particle size of the aqueous dispersion of the urethane polymer (I). According to the study by the present inventors, when the thickness is less than 50 nm, the viscosity may be increased. When the thickness is more than 200 nm, clogging of the head occurs when the filter has poor filterability or is applied to ink for ink jet recording. This is not preferable because a stable effect may not be obtained. More preferably, it is 50-150 nm. These are appropriately adjusted depending on the mass ratio of the three polymers and the amount of the AB block copolymer (III) used.

  In addition, the composite fine particles characterizing the present invention preferably have the above-mentioned particle diameter, and the particle size distribution exhibits a single peak. “Unimodal” means that the distribution is represented by one peak, and the particle distribution of each component of urethane polymer (I), vinyl polymer (II), and AB block copolymer (III). Evidence that these three types of polymers are composed of one distribution having a single particle size, and that the three types of polymers are finely divided into fine particles. Can also be used. That is, according to the study by the present inventors, in the presence of the aqueous dispersion of the urethane polymer (I) and the AB block copolymer (III), a vinyl monomer is added and polymerized to give a vinyl polymer ( The aqueous dispersion obtained by the production method forming II) has a single particle size distribution, and it is considered that these three different polymers are complexed in a good state.

[Method for producing polymer aqueous dispersion containing composite fine particles]
Next, the manufacturing method of the polymer water dispersion of this invention is demonstrated in detail. The production method comprises a urethane polymer (I) in which an anionic group in its structure is neutralized with an alkali and dispersed in water, and a carboxy group of methacrylic acid constituting a polymer block of B is an alkali. In the presence of AB block copolymer neutralized with water and dispersed in water, using a radical polymerization initiator, a vinyl monomer is added and polymerized to obtain a vinyl polymer (II). Three types of polymers are combined to form composite fine particles.

  First, the aqueous dispersion obtained by neutralizing the anionic group of the urethane polymer (I) with an alkali and the carboxy group of the B polymer block are neutralized with an alkali to dissolve the B polymer block in water. And an aqueous dispersion of AB block copolymer (III) in which the polymer block of A forms particles. The aqueous dispersion of urethane polymer (I) is obtained by the above-described method, and the aqueous dispersion of AB block copolymer (III) may be used in the form of the aqueous dispersion, or the urethane polymer (I The solid block of AB block copolymer is added to the water dispersion of (2) and an alkali is added to neutralize the polymer block of B and dissolve in water, and the water of AB block copolymer (III) is added. It may be a dispersion. What is required is that when the vinyl monomer is polymerized, the urethane polymer (I) and the AB block copolymer (III) are present in the aqueous system. According to the study by the present inventors, the composite fine particles of the present invention can be obtained by adding and polymerizing a vinyl monomer in the presence of either one, and then adding either one of the polymers. Can not. Moreover, each solid content in the water is arbitrary, and it is designed by the viscosity and is not particularly limited.

  In this way, a radical polymerization initiator that generates radicals is used in the aqueous dispersion in which the urethane polymer (I) and the AB block copolymer (III) are dispersed, and then a vinyl monomer is added. By polymerizing, composite fine particles characterizing the present invention can be easily obtained. This polymerization method is the same as conventionally known emulsion polymerization. As the radical polymerization initiator used in this case, an aqueous, oily azo or peroxide compound is used. If it is aqueous, it is added to the aqueous system in advance, and if it is oily, it is a vinyl monomer. Used by dissolving in The compound is not particularly limited, and examples of the radical polymerization initiator include peroxide compounds such as lithium persulfate, sodium persulfate, and potassium persulfate; 2,2′-azobis (2- (2 -Imidazolin-2-yl) propane), 2,2'-azobis (2-amidinopropane), azo compounds such as inorganic acids and organic acid salts thereof; oily azo initiators as described above; benzoyl peroxide, lauroyl Oily peroxides such as peroxides and t-butyl lauric acid overesters are used. The amount thereof is 0.1 to 5%, more preferably 0.2 to 1%, based on the weight of the vinyl monomer.

  Next, the process of adding and polymerizing a vinyl monomer will be described. When the vinyl monomer is added, the whole amount of the monomer may be added, but it is preferably dropped and polymerized. The dripping is preferable because heat generated during polymerization of the vinyl monomer can be removed. The dropping speed is not particularly limited. The temperature of the polymerization conditions is not particularly limited, and is preferably 10 hours half-life temperature or more of the radical initiator used. The solid content of the polymer in the aqueous dispersion of composite fine particles obtained is not particularly limited. However, if the solid content is too high, the viscosity becomes high or the composite is not well combined and precipitates. For this reason, Preferably it is 10-50 mass%, More preferably, it is 20-40 mass%. Further, the pH during the polymerization is arbitrary, but it is preferably pH 4-10. If the pH is too low, the ionicity of the urethane polymer (I) and the AB block copolymer (III) in which the anionic group is neutralized to form an aqueous dispersion may weaken and precipitate, If it is too high, the added vinyl monomer may be hydrolyzed. When the pH is acidic to neutral, that is, when the pH is less than 4 to 8, it is preferable to add alkali so that the pH becomes alkaline, that is, around 8 to 10 after the polymerization is completed. This is because when the pH is alkaline, the carboxy group of the AB block copolymer (III) is sufficiently ionized and dissolved in water, thereby improving the water dispersion stability and mechanical stability of the composite fine particles. Because.

  In the step of polymerizing the above-mentioned vinyl monomer, if necessary, other additives may be added for polymerization, or after the polymerization is completed, it may be added. Additives include surfactants, antifoaming agents, leveling agents, thickeners, light stabilizers, UV absorbers, preservatives, pH adjusters, water-soluble organic solvents such as glycerin and glycol solvents, viscosity modifiers Etc.

  The polymer aqueous dispersion of the present invention can obtain sufficient mechanical stability and water dispersion stability of particles without using a surfactant, but it is more stable when used in combination with a surfactant. May be improved. As the surfactant, for example, alkyl sulfate ester salt, alkyl aryl sulfate ester salt, alkyl aryl sulfonate, alkyl naphthalene sulfonate, polyoxyethylene alkyl ether sulfonate, polyoxyethylene alkyl aryl ether sulfonate, Anionic activators such as naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, polyoxyethylene alkyl aryl phosphate ester salt; polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene polyoxy Propylene block polymer, sorbitan fatty acid ester, polyoxyethylene alkylamine ether, fatty acid diethanoldiamide, sorbitan fatty acid ester, acetate Nonionic surfactants such as len alcohols and acetylene glycols; cationic surfactants such as alkylamine salts and quaternary ammonium salts; amphoteric surfactants such as alkylbetaines and amine oxides may be used it can.

  In the present invention, it is more preferable to use a reactive surfactant, and the reactive surfactant is not limited, but specific examples (all are trade names) of commercially available products are exemplified by “Adekari Soap SE-20N”. "Adekaria soap SE-10N", "Adekaria soap PP-70", "Adekaria soap PP-710", "Adekaria soap SR-10", "Adekaria soap SR-20" [above, ADEKA Made by], "Eleminol JS-2", "Eleminol RS-30" (manufactured by Sanyo Chemical Industries, Ltd.), "Latemul S-180A", "Latemul S-180", "Latemul PD-104" [above, Kao Manufactured by AQUALON BC-05, AQUALON BC-10, AQUALON BC-20, AQUALON HS-05, AQUALON HS-10 “Aqualon HS-20”, “New Frontier S-510”, “Aquaron KH-05”, “Aquaron KH-10” (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), “Antox MS-60”, “Antox MS-2N "[manufactured by Nippon Emulsifier Co., Ltd.]," phosphinol TX "[manufactured by Toho Chemical Industry Co., Ltd.], and the like. These can be used in the range of 0.1 to 5% of the vinyl monomer to be added.

  The aqueous dispersion obtained after the polymerization may be used as it is, but it is preferable to perform a filtration step and filter removal in order to remove coarse particles and precipitates. However, even if it is used as it is, there is no problem because it is filtered and removed in the manufacturing process of the pigment dispersion and the manufacturing process of the ink of the present invention. The viscosity of the obtained aqueous dispersion is not particularly limited, but is preferably 4 to 300 mPa · s / 25 ° C. As described above, a polymer aqueous dispersion containing the composite fine particles of the present invention can be obtained.

[Use of polymer dispersion]
Next, the use of the polymer aqueous dispersion containing the composite fine particles of the present invention will be described. The polymer aqueous dispersion of the present invention (hereinafter sometimes simply referred to as an aqueous dispersion) is suitably used as a binder component (film forming component) for inkjet ink. Ink-jet printing is used in recent years for printing not only on paper but also on films of various plastics, printed images of synthetic fibers and cellulose fibers. It is used as a coating component that imparts adhesion to each medium and image durability. The use is added to the pigment dispersion liquid and ink of each color used for inkjet ink.

(Pigment dispersion)
First, a pigment dispersion obtained by using the aqueous dispersion of the present invention will be described. The pigment dispersion is a pigment dispersion composed of at least a pigment, a pigment dispersant, an organic solvent, water, and a binder component, and uses the aqueous dispersion of the present invention as the binder component.

  The pigment dispersion of the present invention is characterized in that the polymer aqueous dispersion of the present invention containing the composite fine particles having the above-described constitution is used as a binder component. The amount as the binder is preferably 50 to 300 parts by mass with respect to 100 parts by mass of the pigment. The composite fine particles are dried to form a resin film after printing, and act to increase the durability of the printed matter. And the viscosity of the ink becomes excessively high, or the pigment concentration is insufficient and color development may be deteriorated. More preferably, it is 60-200 parts.

  Conventionally known pigments are used and are not particularly limited. Organic pigments and inorganic pigments are used, and the organic pigment is not limited in its crystalline state, mixed crystal, solid solution, and the like. Specific examples of organic pigments and inorganic pigments include quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, perylene pigments, phthalocyanine blue pigments, phthalocyanine green pigments, isoindolinone pigments, indigo thioindigo pigments. , Dioxazine pigment, quinophthalone pigment, nickel azo pigment, insoluble azo pigment, soluble azo pigment, high molecular weight azo pigment, carbon black pigment, composite oxide black pigment, iron oxide black pigment, titanium oxide black pigment, azomethine azo And red, green, blue, yellow, orange, purple, black and white pigments selected from the group consisting of black pigments and titanium oxide pigments. The average particle diameter of these pigments is not particularly limited, but preferably the average primary particle diameter is less than 150 nm for organic pigments and less than 300 nm for inorganic pigments and fillers.

  From the viewpoint of color development, dispersibility, and weather resistance, pigments for inks for inkjet inks can be represented by C.I. I. Pigment Blue-15: 3, 15: 4, C.I. I. Pigment red-122, 269, C.I. I. Pigment violet-19, C.I. I. Pigment yellow-74, 155, 180, C.I. I. Pigment green-36, C.I. I. Pigment orange-43, C.I. I. CI pigment black-7 and the like are specifically mentioned, and the average primary particle diameter is preferably less than 150 nm. If necessary, a pigment derivative (synergist) having a similar structure to these pigments and having an anionic group such as a sulfonic acid group bonded thereto may be used. Self-dispersing pigments obtained by introducing a carboxy group, a phosphoric acid group, a sulfonic acid group, a polyethylene glycol chain or the like on the surface of the pigment can also be used. This pigment is a pigment in a pigment dispersion. In the case of carbon black or organic pigment, it is 5 to 30% by mass, more preferably 8 to 20% by mass, and in the case of an inorganic pigment, 10 to 70% by mass, more preferably 20%. The content is ˜60% by mass.

  Next, a pigment dispersant for dispersing the above-described pigment will be described. This pigment dispersant is preferably a (meth) acrylic dispersant or a styrene dispersant, and has a carboxy group-containing monomer such as (meth) acrylic acid, maleic acid, itaconic acid as an anionic group. An acrylic polymer having a structure of type, block copolymer type, graft copolymer type, or dendrimer type can be used. A dispersant having a structure in which this anionic group is neutralized with an alkali and dissolved, dispersed, or emulsified in water is preferable. This is a pigment dispersion obtained by dispersing a pigment with this dispersant, or by dispersing the pigment by coating with this dispersant.

  A particularly preferred form in the present invention is to use the AB block copolymer (III) constituting the aqueous dispersion of the present invention described above as a pigment dispersant. That is, by using the same AB block copolymer as the AB block copolymer (III) constituting the composite fine particles used as the binder component as a pigment dispersant, the same polymer can be obtained by dispersing the pigment particles. Therefore, there is no incompatibility and interaction due to the coexistence of different polymers, and no aggregation or precipitation occurs even when the aqueous polymer dispersion of the present invention is added to the pigment-dispersed liquid. As defined in the present invention, the AB block copolymer (III) used for the composite fine particles is composed of a polymer block of A which is a hydrophobic polymer block, and a hydrophilic polymer which is neutralized with an alkali and dissolved in water. Since it consists of the polymer block of B, it functions effectively as a pigment dispersant. Furthermore, since the polymer block of A is a hydrophobic polymer chain, it is adsorbed and deposited on the pigment, so that it does not desorb, and the polymer block of B dissolves in water, and steric repulsion and electrical repulsion Fine particle dispersion of the pigment is achieved. In addition, since the structure has a hydrophilic chain that dissolves in water, it can be easily dispersed again in an aqueous medium even after drying. The AB block copolymer (III) used for the composite fine particles characterizing the present invention and the AB block copolymer as a pigment dispersant may be exactly the same, but if the monomer composition constituting the same is the same, The above effects can be exhibited regardless of the composition ratio of the monomer. This pigment dispersant can be used in an arbitrary ratio with respect to the pigment, preferably 5 to 100% with respect to 100 parts of the pigment, 10 to 100% in the case of an organic pigment, 50 mass% is more preferable.

  As a liquid medium constituting the pigment dispersion of the present invention, an organic solvent and water are used. Since it is aqueous, water is essential, and the organic solvent is used in consideration of viscosity adjustment, ejection properties when applied to ink, re-dissolvability, drying properties, permeability, and the like. As the organic solvent, various types of solvents can be used. Particularly preferred is a solvent that dissolves in water. Further, from the viewpoints of environmental safety, handleability, workability, etc., the polymer aqueous dispersion film of the present invention From the viewpoint of lowering the film forming temperature at the time of forming the film, and the property that does not hinder the storage stability of the composite fine particle dispersion of the present invention, it is preferable to use the following. For example, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol monomethyl ether , 3-methoxy-3-methyl-1-butanol and at least one selected from the group of glycerin. When the organic pigment is used, the content of the organic solvent is preferably 5 to 40% in the pigment dispersion. In the case of an inorganic pigment, it is preferable to contain 5 to 50% in the liquid medium.

  The pigment dispersion of the present invention has the above as constituents, but other additives may be appropriately added as necessary. As an additive, the additive at the time of manufacturing the above-mentioned composite fine particles can be used. In addition, other binder components such as other colorant components such as dyes and water-insoluble organic solvents may be added as necessary to form a film. For example, polymers such as polyacrylate, polystyrene acrylate, polyolefin, polyester, and polyurethane can be used in the form of a water-soluble polymer, emulsion, and the like, and are not particularly limited. The amount thereof is arbitrary as long as the intended purpose of the present invention is not impaired.

  The method for producing the pigment dispersion of the present invention can be obtained by dispersing the water dispersion, pigment, pigment dispersant, organic solvent, and water of the present invention by a conventionally known method, and is not particularly limited. Examples of the disperser include a kneader such as a kneader, two-roll, three-roll, and Miracle KCK (trade name, manufactured by Asada Steel Corporation), an ultrasonic disperser, and a microfluidizer (trade name) that is a high-pressure homogenizer. , Mizuho Kogyo Co., Ltd.), Nanomizer (trade name, manufactured by Yoshida Kikai Kogyo Co., Ltd.), Starburst (trade name, manufactured by Sugino Machine Co., Ltd.), G-Smasher (trade name, manufactured by Rix Corporation), and the like. In the case of using a bead medium such as glass or zircon, a ball mill, a sand mill, a horizontal media mill disperser, a colloid mill, or the like can be used. The dispersion method is not particularly limited.

  In the present invention, in order to obtain a pigment dispersion having a desired particle size and distribution, the size of the grinding media of the disperser is reduced, the filling rate of the grinding media is increased, and the processing time is increased. It is possible to use a method such as slowing down, classifying with a filter or centrifuge after pulverization, or a combination of these methods. The obtained pigment dispersion may be used as it is, but it is preferable to remove coarse particles by centrifuging or passing through an arbitrary filter. As described above, the pigment dispersion of the present invention can be obtained.

  Regarding the physical properties of the pigment dispersion of the present invention obtained as described above, the physical properties such as viscosity are not particularly limited and are arbitrary. The viscosity range is 1 to 100 mPa · s, preferably 3 to 50 mPa · s, but is not limited because it varies depending on the desired pigment concentration and application. Other physical properties are not particularly limited. The pigment dispersion of the present invention can be used as a colorant for various articles. For example, it can be used as a material for pigment colorant compositions such as paint, gravure ink, offset ink, ink jet recording ink, coating agent, stationery color and the like. In particular, it is suitable as a colorant for water-based ink-jet inks because it can reduce viscosity and increase the fineness of the pigment and has good long-term storage stability.

  The ink for inkjet recording of the present invention is characterized by containing the aqueous polymer dispersion of the present invention or the pigment dispersion of the present invention described above. That is, an ink can be obtained using the pigment dispersion in the form containing the aqueous dispersion of the present invention as the binder component. However, the present invention is not limited to this, and a conventional pigment dispersion excluding the binder component can be prepared in advance, and the aqueous dispersion of the present invention can be added to obtain an ink. There are no particular limitations on the production method, formulation, and materials to be blended, and any material can be used.

[Preparation of AB Block Copolymer (III)]
As described above, the AB block copolymer (III) (hereinafter also referred to as copolymer (III)) constituting the composite fine particles characterizing the present invention is also used as a pigment dispersant constituting the aqueous pigment dispersion of the present invention. Although useful, the block copolymer is preferably obtained by the following polymerization method. As described above, the copolymer (III) used in the present invention is an AB block copolymer having a uniform molecular weight, but is preferably produced by a living radical polymerization method. In particular, it is preferable to use living radical polymerization using a polymerization initiating compound. Specifically, the method includes living radical polymerization of a monomer component containing the methacrylate monomers in the presence of a polymerization initiating compound and a catalyst, wherein the polymerization initiating compound is at least one of iodine and an iodine compound, Is a production method in which is a compound selected from the group consisting of phosphorus halides, phosphite compounds, phosphinate compounds, imide compounds, phenol compounds, diphenylmethane compounds, and cyclopentadiene compounds It is preferable to do. According to the production method, the AB block copolymer (III) can be easily obtained. By using the copolymer obtained by this method, the production process of the polymer aqueous dispersion of the present invention can be simplified and reduced. Cost can be reduced.

  Various methods have been invented for living radical polymerization, such as nitroxide method (NMP method) utilizing dissociation and bonding of amine oxide radicals, heavy metals such as copper, ruthenium, nickel and iron, and these heavy metals and complexes. Atom transfer radical polymerization (ATRP method) in which a halogen compound is used as a starting compound, using a ligand to form, a dithiocarboxylic acid ester or a xanthate compound as a starting compound, and an addition polymerizable monomer and radical initiation Reversible addition-fragmentation chain transfer polymerization (RAFT method) and MIXX method, a method using heavy metals such as organic tellurium, organic bismuth, organic antimony, antimony halide, organic germanium, germanium halide (DT) Law). These methods also use a polymerization initiating compound and can be applied to the present invention.

  However, these methods have a problem in obtaining the desired copolymer (III) in the present invention. For example, in the NMP method, an amine oxide such as a tetramethylpiperidine oxide radical is used, but it is necessary to polymerize under a high temperature condition of 100 ° C. or higher. There is also a problem of not progressing.

  In the ATRP method, it is necessary to use a heavy metal, and since it is a polymerization method involving redox, it is necessary to remove oxygen. In the polymerization method in which a complex is formed using an amine compound as a ligand, the formation of the complex is hindered if an acidic substance is present in the polymerization system. Therefore, it is difficult to polymerize an addition polymerizable monomer having an acid group as it is. . Although it is necessary to polymerize the monomer which protected the acid group with the protecting group and to remove the protecting group after the polymerization, it is complicated and it is not easy to introduce the acid group into the polymer block.

  The RAFT method and the MADIX method require special compounds such as dithiocarboxylic acid esters and xanthate compounds, and these are sulfur-based compounds, so that the resulting polymer tends to have an unpleasant sulfur-based odor and is colored. In some cases, it is necessary to remove odor and coloring from the obtained polymer. In addition, polymerization of methacrylate monomers may not be successful. In addition, sulfur esters such as dithiocarboxylic acid esters and xanthate compounds may be decomposed by amino groups, resulting in a polymer having a low molecular weight or a sulfur odor.

  Furthermore, in the DT method, it is necessary to use heavy metals as in the ATRP method, it is necessary to remove heavy metals from the obtained polymer, and there is also a problem of purification of waste water containing the generated heavy metals. Under the circumstances described above, the polymerization method described above does not require the use of heavy metal compounds, does not require purification of the polymer, does not require the synthesis of special compounds, and uses relatively inexpensive materials on the market. The copolymer (III) desired in the present invention can be easily produced simply by this. In addition, the polymerization conditions are mild, the polymerization can be carried out under the same conditions as in the conventional radical polymerization method, and it should be noted that a monomer having a carboxy group or the like can be directly subjected to living radical polymerization.

  As described above, the copolymer (III) desired in the present invention can be easily obtained by a production method having a step (polymerization step) of living radical polymerization of a monomer component containing a methacrylate monomer in the presence of a polymerization initiating compound and a catalyst. And can be obtained reliably. In this living radical polymerization, various functional groups can be used.

  In the polymerization step, at least one of iodine and an iodine compound is used as a polymerization initiating compound, and a monomer component containing a methacrylate monomer is polymerized by living radical polymerization. When heat or light is applied to iodine or iodine compound used as a polymerization initiating compound, iodine radicals are dissociated. And in the said manufacturing method, after a monomer is inserted in the state which the iodine radical dissociated, the iodine radical immediately couple | bonds with a polymer terminal radical again, is stabilized, and a polymerization reaction advances, preventing termination reaction.

  Specific examples of the iodine compound include alkyl iodides such as 2-iodo-1-phenylethane and 1-iodo-1-phenylethane; 2-cyano-2-iodopropane, 2-cyano-2-iodobutane, 1 Cyano group-containing iodides such as cyano-1-iodocyclohexane, 2-cyano-2iodo-2,4-dimethylpentane, 2-cyano-2-iodo-4-methoxy-2,4-dimethylpentane, and the like. Can be mentioned.

  As these iodine compounds, commercially available products may be used as they are, but those prepared by a conventionally known method may also be used. For example, an iodine compound can be obtained by reacting an azo compound such as azobisisobutyronitrile with iodine. Further, the iodine compound can be obtained by reacting an organic halide obtained by substituting iodine of the above iodine compound with a halogen atom such as bromine or chlorine and an iodide salt such as quaternary ammonium iodide or sodium iodide, and exchanging the halogen. Can be obtained.

  In the polymerization step, a catalyst capable of extracting iodine of the polymerization initiating compound is used together with the polymerization initiating compound. Examples of the catalyst include phosphorus compounds such as phosphorus halides, phosphite compounds, and phosphinate compounds; nitrogen compounds such as imide compounds; oxygen compounds such as phenol compounds; diphenylmethane compounds and cyclopentadiene compounds. The following hydrocarbon compounds can be used. These catalysts can be used alone or in combination of two or more.

  Specific examples of the phosphorus compound include phosphorus triiodide, diethyl phosphite, dibutyl phosphite, ethoxyphenyl phosphinate, phenylphenoxy phosphinate and the like. Examples of the nitrogen-based compound include succinimide, 2,2-dimethylsuccinimide, maleimide, phthalimide, N-iodosuccinimide, and hydantoin. Examples of the oxygen compound include phenol, hydroquinone, methoxyhydroquinone, t-butylphenol, catechol, and di-t-butylhydroxytoluene. Examples of the hydrocarbon compound include cyclohexadiene and diphenylmethane.

  The use amount (number of moles) of these catalysts is preferably less than the use amount (number of moles) of the polymerization initiating compound. If the amount of the catalyst used (number of moles) is too large, polymerization may be over-controlled and polymerization may not proceed easily. Moreover, it is preferable that the temperature (polymerization temperature) in the case of living radical polymerization shall be 30-100 degreeC. If the temperature is too high, iodine at the polymerization terminal is decomposed, and the terminal may not be stable and living polymerization may not be performed. Further, in the polymerization method used in the present invention, iodine is bonded to the terminal, and it is preferable that the iodine is dissociated as a radical to generate a radical and the terminal is stable. Here, in the case of acrylate, vinyl, etc., the terminal is a secondary iodide, which is relatively stable and does not come off as an iodine radical, and there is a possibility that the polymerization does not proceed or the distribution becomes wide. Although dissociation can be carried out by raising the temperature, it is preferred that the polymerization be carried out gently in the above temperature range from the viewpoint of environment and energy. Therefore, a tertiary iodide which is easy to generate radicals and is relatively stable is preferable, and a methacrylate monomer is suitable for the living radical polymerization used in the present invention.

  In the polymerization step, a polymerization initiator that can generate radicals is usually added. As the polymerization initiator, conventionally known azo initiators and peroxide initiators are used. It is preferable to use a polymerization initiator that generates radicals sufficiently within the above polymerization temperature range. Specifically, it is preferable to use an azo initiator such as 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile). The amount of the polymerization initiator used is preferably 0.001 to 0.1 mol times, more preferably 0.002 to 0.05 mol times with respect to the monomer. If the amount of the polymerization initiator used is too small, the polymerization reaction may not proceed sufficiently. On the other hand, if the amount of the polymerization initiator used is too large, a normal radical polymerization reaction that is not a living radical polymerization reaction may proceed as a side reaction.

  Living radical polymerization may be bulk polymerization that does not use an organic solvent, but is preferably solution polymerization that uses an organic solvent. The organic solvent is preferably one that can dissolve components such as a polymerization initiator compound, a catalyst, a monomer component, and a polymerization initiator.

  Specific examples of organic solvents include hexane, octane, decane, isodecane, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene and other hydrocarbon solvents; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, hexanol, benzyl alcohol , Alcohol solvents such as cyclohexanol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol propyl ether, diglyme, triglyme, tetra Glyme, dipropylin glycol dimethyl ether, butyl carbonate Glycol solvents such as bitol, butyltriethylene glycol, methyl dipropylene glycol, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol butyl ether acetate, diethylene glycol monobutyl ether acetate; diethyl ether, dipropyl ether, methylcyclopropyl ether, Ether solvents such as tetrahydrofuran, dioxane, anisole; ketone solvents such as methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, isophorone, acetophenone; methyl acetate, ethyl acetate, butyl acetate, propyl acetate, methyl butyrate, ethyl butyrate, caprolactone , Methyl lactate, ethyl lactate, dimethyl oxalate, dimethyl adipate Ester solvents such as dimethyl glutarate; halogenated solvents such as chloroform and dichloroethane; amide solvents such as dimethylformamide, dimethylacetamide, pyrrolidone, N-methylpyrrolidone, caprolactam, dimethyl sulfoxide, sulfolane, tetramethylurea, Examples thereof include ethylene carbonate, propylene carbonate, dimethyl carbonate and the like. These organic solvents can be used alone or in combination of two or more.

  Further, these organic solvents used for the polymerization can be used as they are as a solution of the AB block copolymer (III), and if necessary, the copolymer (III) can be taken out from the solution and solidified. . As this method, for example, it is possible to obtain a polymer solid by precipitating in a poor solvent, filtering and drying, or drying the solution and taking out only the polymer. As described above, the obtained solid copolymer (III) may be used as it is, or an aqueous alkali solution may be added to the above solution to neutralize the carboxy group to form an aqueous solution. Alternatively, when it is taken out as a solid, it can be used by adding it to an aqueous medium, neutralizing the carboxy group with an alkali, and dissolving and dispersing in water.

  In the case of the above solution polymerization, the solid content concentration (monomer concentration) of the polymerization solution is preferably 5 to 80% by mass, and more preferably 20 to 60% by mass. When the solid content concentration of the polymerization liquid is less than 5% by mass, the monomer concentration may be too low to complete the polymerization. On the other hand, when the solid content concentration of the polymerization liquid exceeds 80% by mass or bulk polymerization, the viscosity of the polymerization liquid becomes too high, and stirring tends to be difficult and the polymerization yield tends to decrease. Living radical polymerization is preferably carried out until the monomer runs out. Specifically, the polymerization time is preferably 0.5 to 48 hours, and more preferably 1 to 24 hours. The polymerization atmosphere is not particularly limited, and may be an atmosphere in which oxygen exists within a normal range or a nitrogen stream atmosphere. The material (monomer, etc.) used for the polymerization may be a material from which impurities have been removed by distillation, activated carbon treatment, alumina treatment, or the like. Of course, you may use a commercial item as it is. Furthermore, polymerization may be performed under light shielding, or polymerization may be performed in a transparent container such as glass.

The copolymer (III) used in the present invention is one in which the molecular weight of the main chain is controlled by adjusting the use balance of the methacrylate monomers and the polymerization initiating compound at the time of the above living radical polymerization. Become. Specifically, a polymer whose main chain has an arbitrary molecular weight can be obtained by appropriately setting the number of moles of the monomer with respect to the number of moles of the polymerization initiating compound. For example, when 1 mol of a polymerization initiating compound is used and 500 mol of a monomer having a molecular weight of 100 is used for polymerization, a polymer having a theoretical molecular weight of “1 × 100 × 500 = 50000” can be obtained. That is, the theoretical molecular weight of the main chain polymer can be calculated by the following formula (1). The “molecular weight” is a concept including both the number average molecular weight (Mn) and the weight average molecular weight (Mw). The amount of the polymerization initiating compound is as described above.
“Theoretical molecular weight of main chain polymer” = “1 mol of polymerization initiation compound” × “monomer molecular weight” × “number of moles of monomer / number of moles of polymerization initiation compound” (1)

  In the polymerization process, there may be a case in which a bimolecular termination or a disproportionation side reaction is involved, so that a main chain polymer having the above theoretical molecular weight may not be obtained. It is preferable that these are obtained without causing side reactions. The polymerization rate may not be 100%. Furthermore, once the polymerization is completed, the polymerization may be completed by adding a polymerization initiating compound or a catalyst and consuming the remaining monomer.

  In addition, the order of block polymerization of the copolymer (III) is as follows. After polymerizing a polymer block of A substantially insoluble in water, a mixture of monomers having a carboxy group is added to form a polymer block of B. Alternatively, after forming a polymer block of a monomer having a carboxy group, a monomer that forms another polymer block may be added and polymerized so as to be substantially insoluble in water. . Preferably, after forming a polymer block substantially insoluble in water, a monomer having a carboxy group is added and polymerized.

  The copolymer (III) can be obtained as described above. As described above, the aqueous dispersion of the present invention is prepared by neutralizing the carboxy group of the B polymer block of the AB block copolymer (III) with an alkali to form an aqueous solution. In the presence of an aqueous dispersion, a vinyl monomer is added and polymerized to form a vinyl polymer (II), and these three types of polymers are combined. As the alkali to be neutralized at this time, conventionally known alkalis are used and are not particularly limited. Specific examples include ammonia; alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and 60 mol% of the carboxy group. As described above, preferably 100% or more is used to make an aqueous solution.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited at all by these examples. In the text, “part” or “%” is based on mass.

[Synthesis Example 1: Synthesis of AB Block Copolymer (III) (1)]
The following was charged into a 1-liter separable flask reactor equipped with a stirrer, condenser, thermometer and nitrogen inlet tube, and the block copolymer A was synthesized as follows. Specifically, in order to obtain 408.8 parts of propylene glycol monopropyl ether (hereinafter abbreviated as PPG) as an organic solvent and iodine compound as a polymerization initiating compound, 3.8 parts of iodine and 2 , 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (hereinafter abbreviated as V-70), 0.1 part of diphenylmethane (hereinafter abbreviated as DPM) as a catalyst, , 158.6 parts of benzyl methacrylate (hereinafter abbreviated as BzMA) was charged and stirred, and the mixture was heated to 45 ° C.

  After 2 hours, the brown color of iodine disappeared, and during this time, it was confirmed that the polymerization initiator V-70 reacted with iodine to become a polymerization initiator compound which was an iodine compound. Further, polymerization was carried out for 3 hours while maintaining the above temperature, and a part of the reaction solution was sampled at this point. When the solid content of this sample was measured, it was 29.4%, and the polymerization rate calculated based on this was almost 100%. Hereinafter, the polymerization rate was calculated by the same method as described above. Further, when measured by GPC using tetrahydrofuran (hereinafter abbreviated as THF) as a developing solvent, the number average molecular weight (Mn) was 5100 (polystyrene conversion value) and the dispersity (PDI) was 1.20. Hereinafter, the number average molecular weight is a value measured by a differential refractive index detector of GPC using a THF solvent as a developing solvent. A block copolymer of A was obtained as described above.

  Next, after the temperature of the polymer block solution of A obtained above was lowered to 40 ° C., 38.7 parts of methacrylic acid (hereinafter abbreviated as MAA) and 132.2 parts of BzMA were added. Polymerization was performed for a time to form a polymer block of B. The acid value in the B chain is calculated to be 149.9 mgKOH / g. The acid value in the B chain was calculated as follows.

First, the amount of MAA per part of B chain composition is determined.
38.7 / (38.7 + 132.2) = 0.23 parts Next, when the molecular weight of MAA is 86.1 and the molecular weight of KOH is 56.1, the acid value of the B chain is calculated by the following formula: . Hereinafter, the acid value in the B chain was calculated by the same method.
(0.23 / 86.1) × 56.1 × 1000 = 149.9 mgKOH / g

  This polymer solution had a solid content of 50.0%, and it was confirmed that the polymerization rate was almost 100%. The number average molecular weight was 12,200, the degree of dispersion was 1.37, and the peak top molecular weight (abbreviated as Pt) was 16,800. It was considered that the block copolymer was formed from the fact that it was confirmed that the molecular weight was shifted to the higher molecular weight side than when the polymer block of A was formed. The molecular weight of the polymer block of B can be calculated as a value obtained by subtracting the number average molecular weight of the polymer block of A from the number average molecular weight of the AB block copolymer, and calculated as Mn = 7100.

  Further, after the sample was diluted with toluene and ethanol, the acid of the whole AB block copolymer was measured by acid-base titration using a 0.1% ethanolic potassium hydroxide solution with a phenolphthalein solution as an indicator. When the value was determined, the actually measured acid value was 84.7 mgKOH / g. In the following, the actually measured acid values are values calculated by performing the same operation as described above.

  Next, the reaction solution was transferred to a 2 L beaker, and 1 L of water was gradually added while stirring using a stirrer to precipitate a polymer. The precipitated polymer was subjected to suction filtration with a Buchner funnel, and then the collected filtrate was washed with 2 L of water and dried in a dryer at 80 ° C. for 24 hours to obtain a solid AB block copolymer. This is referred to as ABP-1.

[Synthesis Example 2: Synthesis of AB Block Copolymer (III) (2)]
Using the same apparatus as in Synthesis Example 1, 290.9 parts of PPG, 3.8 parts of iodine, 9.3 parts of V-70, 0.1 part of DPM, and cyclohexyl methacrylate (hereinafter referred to as CHMA). 113.6 parts) was stirred and polymerized at 45 ° C. for 5 hours to form A block copolymer. The polymerization rate was almost 100%. Moreover, in the molecular weight measurement by GPC, the number average molecular weight (Mn) was 3500, and dispersion degree (PDI) was 1.14.

  After the temperature of the polymer block solution of A was lowered to 40 ° C., 45.2 parts of MAA and 119.0 parts of BzMA were added, and polymerization was further performed for 4 hours to form a polymer block of B. The theoretical acid value in the B chain is 179.5 mg KOH / g. The solid content was 49.8%, the polymerization rate was almost 100%, the Mn was 8800, the degree of dispersion was 1.30, and the peak top molecular weight (Pt) was 12400. The number average molecular weight of the polymer block B calculated from the Mn value is 5300. Moreover, the actually measured acid value of the obtained copolymer was 106.0 mgKOH / g. Next, an AB block copolymer solid was obtained in the same manner as in Synthesis Example 1. This is referred to as ABP-2.

[Synthesis Example 3: Synthesis of AB Block Copolymer (III) (3)]
Using the same apparatus as in Synthesis Example 1, 411.0 parts of PPG, 3.8 parts of iodine, 9.3 parts of V-70, 0.1 part of DPM, 92.5 parts of BzMA and CHMA 88.3 parts were charged and stirred, and polymerization was carried out at 45 ° C. for 5 hours to form a block copolymer of A. The polymerization rate was almost 100%. Further, in the molecular weight measurement by GPC, the number average molecular weight (Mn) was 5700, and the dispersity (PDI) was 1.21.

  After the temperature of the polymer block solution of A was lowered to 40 ° C., 45.2 parts of MAA and 158.6 parts of BzMA were added, followed by polymerization for 4 hours to form a polymer block of B. The theoretical acid value in the B chain is 144.5 mg KOH / g. The solid content was 50.3%, the polymerization rate was almost 100%, Mn was 12100, the degree of dispersion was 1.39, and Pt was 17400. The number average molecular weight of the polymer block of B calculated from the value of Mn is 6400. The actually measured acid value of the obtained copolymer was 73.6 mgKOH / g. Next, an AB block copolymer solid was obtained in the same manner as in Synthesis Example 1. This is referred to as ABP-3.

[Synthesis Example 4: Synthesis of AB Block Copolymer (III) (4)]
Using the same apparatus as in Example 1, 366.2 parts of PPG, 3.8 parts of iodine, 9.3 parts of V-70, 0.1 part of DPM, and 158.6 parts of BzMA are charged. And a polymerization was carried out at 45 ° C. for 5 hours to form a block copolymer of A. The polymerization rate was almost 100%. Moreover, in the molecular weight measurement by GPC, the number average molecular weight (Mn) was 5000, and dispersion degree (PDI) was 1.20.

  After the temperature of the polymer block solution of A was lowered to 40 ° C., 32.3 parts of MAA, 132.2 parts of BzMA, methoxypolyethylene glycol methacrylate (n≈9, “trade name PME-400”, manufactured by NOF Corporation, (Hereinafter abbreviated as “PME-400”) was added in an amount of 30.0 parts, followed by further polymerization for 4 hours to form a polymer block of B. The theoretical acid value in the B chain is 108.2 mg KOH / g. The solid content was 49.8%, the polymerization rate was almost 100%, Mn was 10400, the degree of dispersion was 1.35, and Pt was 14900. The number average molecular weight of the polymer block of B calculated from the value of Mn is 5400. The actually measured acid value of the obtained copolymer was 58.5 mgKOH / g. Next, an AB block copolymer solid was obtained in the same manner as in Synthesis Example 1. This is referred to as ABP-4.

Table 1 shows the compositions and physical properties of the polymers obtained in the above synthesis examples.

[Synthesis Example 5: Synthesis of Urethane Polymer (I) (1)]
In a reactor of a 1 liter separable flask equipped with a stirrer, a condenser, a thermometer, a nitrogen gas inlet tube and a decompression device, 120.0 parts of polypropylene glycol having an average molecular weight of 2000 (hereinafter abbreviated as PPG-2000), 1.4 parts 1,4-butanediol (hereinafter abbreviated as 1,4-BD), 28.2 parts dimethylolpropionic acid (hereinafter abbreviated as DMPA), and isophorone diisocyanate (hereinafter abbreviated as IPDI). 95.0 parts and 24.5 parts of acetone as a diluting solvent were charged and stirred while flowing nitrogen gas, and heated to 70 ° C. While maintaining this temperature, the reaction was performed for 6 hours to obtain a urethane prepolymer having a terminal NCO group.

  Next, the reaction solution was cooled to 40 ° C., and 33.0 parts of 2- (dimethylamino) ethyl methacrylate (hereinafter abbreviated as DMAEMA) was gradually added with stirring to neutralize the carboxy group in the urethane prepolymer. Thereafter, a mixture of 10.2 parts of isophoronediamine and 431.7 parts of ion-exchanged water was added, vigorously stirred and mixed, and further stirred for 1 hour to carry out a chain extension reaction. After depressurizing the reaction vessel, the mixture was heated to 65 ° C. and desolvated for 1 hour to obtain a urethane polymer aqueous dispersion.

  The solid content of this urethane polymer aqueous dispersion was measured and found to be 39.5%. Its theoretical acid value is 46.3 mg KOH / g. The average particle diameter determined by the light scattering method was 52 nm. 1 g of the obtained sample was taken and diluted with 50 ml of ion-exchanged water, 2 ml of 1M dilute hydrochloric acid was added to precipitate a polymer, and GPC measurement was carried out on what was dried with a dryer at 100 ° C. The number average molecular weight ( Mn) was 45800, and the degree of dispersion (PDI) was 5.35. This is referred to as PUD-1.

[Synthesis Example 6: Synthesis of Urethane Polymer (I) (2)]
Using the same apparatus as in Synthesis Example 5, 120.0 parts of etanacol UH-200 (manufactured by Ube Industries, polycarbonate diol having an average molecular weight of 2000), 1.4 parts of 1,4-BD, 28.2 parts of DMPA Part, 95.0 parts of IPDI, and 24.5 parts of acetone as a diluting solvent were stirred while flowing nitrogen gas, and heated to 70 ° C. While maintaining this temperature, the reaction was performed for 6 hours to obtain a urethane prepolymer having a terminal NCO group.

  Next, the reaction solution was cooled to 40 ° C., and 21.3 parts of triethylamine was gradually added with stirring to neutralize the carboxy group in the urethane prepolymer, and then 8.7 parts of 1,6-hexamethylenediamine and ions A chain extension reaction was carried out by adding 411.8 parts of exchange water and stirring vigorously, followed by further stirring for 1 hour. After depressurizing the reaction vessel, the mixture was heated to 65 ° C. and desolvated for 1 hour to obtain a urethane polymer aqueous dispersion.

  The solid content of this urethane polymer aqueous dispersion was measured and found to be 39.7%. Its theoretical acid value is 46.3 mg KOH / g. The average particle diameter determined by the light scattering method was 61 nm. Moreover, the number average molecular weight (Mn) by GPC measurement was 56700, and dispersion degree (PDI) was 5.41. This is referred to as PUD-2.

[Example 1: Synthesis of composite fine particles (1)]
The AB block copolymer (III) as defined in the present invention of the solid material prepared in Synthesis Example 1 previously in a 1-liter separable flask equipped with a stirrer, condenser, dropping funnel, thermometer and nitrogen inlet tube. 40.0 parts of ABP-1 and 5.4 parts of N, N-dimethylaminoethanol (hereinafter abbreviated as DMAE) as a neutralizing agent for the carboxy group in the ABP-1 and 358.1 ion-exchanged water The solution was heated to 80 ° C. while flowing nitrogen gas and stirred for 1 hour to form an aqueous solution. The pH of this solution was 8.5.

  Subsequently, the temperature in the container was lowered to 50 ° C., and 202.5 parts of PUD-1 (solid content 39.5%), which was the urethane polymer (I) previously prepared in Synthesis Example 5 and defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.6 part of potassium persulfate (hereinafter abbreviated as KPS) was added and dissolved as a polymerization initiator. To this, a mixture of 40.0 parts of styrene (hereinafter abbreviated as St) and 40.0 parts of butyl acrylate (hereinafter abbreviated as BA) as a vinyl monomer was dropped over 2 hours using a dropping funnel, By polymerization, a vinyl polymer (II) defined in the present invention was obtained. After completion of the dropping, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite resin fine particles essential to contain three kinds of polymers. The mass ratio of the three polymers I: II: III is 40:40:20.

  The obtained composite fine particles had an average particle size of 124 nm by the light scattering method and the particle size distribution was unimodal. Thus, it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 29.8%, the pH was 8.6, and the viscosity at 25 ° C. was measured using a cone plate viscometer. As a result, it was 4.8 mPa · s. The viscosity of the composite fine particle aqueous dispersion was measured in the same manner as described below.

  1 g of the obtained sample was taken and diluted with 50 ml of ion-exchanged water, 2 ml of 1M dilute hydrochloric acid was added to precipitate the polymer, and GPC measurement was performed on the polymer dried by a dryer at 100 ° C. As a result, the vinyl polymer (II) had a number average molecular weight of 165400 and a dispersity of 3.21. This is referred to as AUE-1. The molecular weight of the vinyl polymer (II) was also measured as described above.

[Example 2: Synthesis of composite fine particles (2)]
Using the same apparatus as in Example 1, 60.0 parts of the solid ABP-2 prepared in Synthesis Example 2 above, 10.1 parts of DMAE as a neutralizing agent for the carboxy group in the ABP-2, 400.5 parts of ion-exchanged water was charged, heated to 80 ° C. while flowing nitrogen gas, and stirred for 1 hour to form an aqueous solution. The pH of this solution was 8.8.

  Next, the temperature in the container was lowered to 50 ° C., and 151.1 parts of PUD-2 (solid content 39.7%), which was the urethane polymer (I) previously prepared in Synthesis Example 6 and defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.6 parts of KPS was added and dissolved, 39.6 parts of cyclohexyl acrylate (hereinafter abbreviated as CHA), 39.6 parts of BA, and ethylene as a crosslinking agent. A mixture of 0.8 parts of glycol dimethacrylate (hereinafter abbreviated as EDMA) was dropped over 2 hours using a dropping funnel and polymerized to obtain a vinyl polymer (II) as defined in the present invention. After completion of dropping, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite fine particles containing three kinds of polymers. The mass ratio of the three polymers I: II: III is 30:40:30.

  The obtained composite fine particles had an average particle size of 105 nm by the light scattering method and the particle size distribution was unimodal, so that it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 29.9%, the pH was 8.9, and the viscosity was 5.0 mPa · s. This is referred to as AUE-2.

[Example 3: Synthesis of composite fine particles (3)]
Using the same apparatus as in Example 1, 80.0 parts of the solid ABP-3 previously prepared in Synthesis Example 3 was used, and sodium hydroxide (NaOH) was used as a neutralizing agent for the carboxy group in the ABP-3. 4.2 parts and 355.7 parts of ion-exchanged water were charged, and heated to 80 ° C. while flowing nitrogen gas, and stirred for 1 hour to form an aqueous solution. The pH of this solution was 9.0.

  Next, the temperature in the container was lowered to 50 ° C., and 201.5 parts of PUD-2 (solid content 39.7%), which was previously prepared in Synthesis Example 6 and was the urethane polymer (I) defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.3 part of KPS was added and dissolved, 16.0 parts of St, and 24.0 parts of 2-ethylhexyl acrylate (hereinafter abbreviated as 2-EHA). The mixture was dropped using a dropping funnel over 2 hours and polymerized to obtain a vinyl polymer (II) defined in the present invention. After completion of dropping, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite fine particles containing three kinds of polymers. The mass ratio of the three polymers I: II: III is 40:20:40.

  The average particle diameter of the obtained composite fine particles by light scattering method was 86 nm and the particle size distribution was unimodal. Therefore, it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 29.7%, the pH was 9.0, and the viscosity was 5.3 mPa · s. This is referred to as AUE-3. The number average molecular weight of the vinyl polymer (II) obtained by polymerization as measured by GPC was 216500, and the degree of dispersion was 3.35.

[Example 4: Synthesis of composite fine particles (4)]
Using the same apparatus as in Example 1, 80.0 parts of the solid ABP-4 prepared in Synthesis Example 4 previously, 3.3 parts of NaOH as a neutralizing agent for the carboxy group in the ABP-4, 415.3 parts of ion-exchanged water was charged, heated to 80 ° C. while flowing nitrogen gas, and stirred for 1 hour to form an aqueous solution. The pH of this solution was 8.5.

  Next, the temperature in the container was lowered to 50 ° C., and 101.3 parts of PUD-1 (solid content 39.5%), which was previously prepared in Synthesis Example 5, which is the urethane polymer (I) defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.6 part of KPS was added and dissolved, 55.4 parts of ethyl acrylate (hereinafter abbreviated as EA), 23.8 parts of BA, and 0.2 part of EDMA. 8 parts of the mixture was dropped using a dropping funnel over 2 hours and polymerized to obtain a vinyl polymer (II) defined in the present invention. After completion of dropping, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite fine particles containing three kinds of polymers. The mass ratio of the three polymers I: II: III is 20:40:40.

  The obtained composite fine particles had an average particle size of 103 nm by the light scattering method and the particle size distribution was unimodal, so that it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 30.0%, the pH was 8.6, and the viscosity was 4.7 mPa · s. This is referred to as AUE-4.

[Example 5: Synthesis of composite fine particles (5)]
Using the same apparatus as in Example 1, 40.0 parts of ABP-3 in the solid matter prepared in Synthesis Example 3 above, 4.7 parts of AMP as a neutralizing agent for the carboxy group in ABP-3, 419.1 parts of ion-exchanged water was charged, heated to 80 ° C. while flowing nitrogen gas, and stirred for 1 hour to form an aqueous solution. The pH of this solution was 8.0.

  Next, the temperature in the container was lowered to 50 ° C., and 101.3 parts of PUD-1 (solid content 39.5%), which was previously prepared in Synthesis Example 5, which is the urethane polymer (I) defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.9 part of KPS was added and dissolved, and 59.4 parts of benzyl acrylate (hereinafter abbreviated as BzA), 59.4 parts of BA, and 1. Two parts of the mixture was dropped using a dropping funnel over 2 hours and polymerized to obtain a vinyl polymer (II) defined in the present invention. After completion of dropping, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite fine particles containing three kinds of polymers. The mass ratio of the three polymers I: II: III is 20:60:20.

  The obtained composite fine particles had an average particle diameter of 137 nm as measured by the light scattering method, and the particle size distribution was unimodal. Thus, it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 30.4%, the pH was 8.3, and the viscosity was 6.2 mPa · s. This is referred to as AUE-5.

[Example 6: Synthesis example (6) of vinyl polymer (II) and composite fine particles]
Using the same apparatus as in Example 1, 40.0 parts of the solid ABP-4 previously prepared in Synthesis Example 4 and 28% aqueous ammonia (hereinafter referred to as the neutralizing agent for the carboxy group in the ABP-4) NH3 (abbreviated as NH3) and ion-exchanged water 352.5 parts were charged, heated to 80 ° C. while flowing nitrogen gas, and stirred for 1 hour to form an aqueous solution. The pH of this solution was 8.2.

  Next, the temperature in the container was lowered to 50 ° C., and 201.5 parts of PUD-2 (solid content 39.7%), which was previously prepared in Synthesis Example 6 and was the urethane polymer (I) defined in the present invention. The mixture was added and homogenized by stirring for 10 minutes. After raising the temperature in the reaction vessel to 75 ° C., 0.6 parts of KPS was added and dissolved, and 28.0 parts of St, 48.0 parts of BA, and 4 parts of acrylonitrile (hereinafter abbreviated as AN). Was dropped over 2 hours using a dropping funnel and polymerized to obtain a vinyl polymer (II) defined in the present invention. After completion of the dropping, the mixture was aged at the same temperature for 4 hours, cooled, and then filtered through a 400 mesh wire netting to obtain an aqueous dispersion of composite fine particles essential to contain three kinds of polymers. The mass ratio of the three polymers I: II: III is 40:40:20.

  The obtained composite fine particles had an average particle diameter of 118 nm by a light scattering method and a particle size distribution that was unimodal. Thus, it was confirmed that the intended composite fine particles defined in the present invention were obtained. The solid content was 30.4%, the pH was 8.5, and the viscosity was 6.0 mPa · s. This is referred to as AUE-6. The vinyl polymer (II) formed by polymerization as described above had a number average molecular weight of 368900 as measured by GPC and a dispersity of 3.31.

[Comparative Example 1: System not containing AB block copolymer (III) during polymerization of vinyl monomer]
Using the same apparatus as in Example 1, 202.5 parts of PUD-1 (solid content 39.5%), which is the urethane polymer (I) previously defined in Synthesis Example 5, and defined in the present invention, 250.8 parts of exchange water was charged, the temperature in the reaction vessel was raised to 75 ° C. while flowing nitrogen gas, and then 1.0 part of KPS was added and dissolved as a polymerization initiator. Next, as a vinyl monomer, a mixture of 40.0 parts of styrene and 40.0 parts of BA was dropped using a dropping funnel over 2 hours for polymerization. However, many precipitates were generated in the middle of dropping, and a uniform dispersion could not be obtained. The reason for this is considered to be that, unlike the example, the vinyl polymer (II) was not stably atomized because the AB block copolymer (III) was not present in the polymerization system of the vinyl monomer. .

[Comparative Example 2: System in which urethane polymer (I) was mixed later]
Using the same apparatus as in Example 1, 40.0 parts of ABP-1 which is the AB block copolymer (III) defined in the present invention of the solid previously prepared in Synthesis Example 1 was used as a neutralizing agent. 4.4 parts of DMAE and 480.7 parts of ion-exchanged water were charged, heated to 80 ° C. while flowing nitrogen gas, and dissolved by heating for 1 hour to obtain an aqueous solution. The pH of this solution was 8.5. After the temperature in the reaction vessel is lowered to 75 ° C., 1.0 part of KPS is added and dissolved as a polymerization initiator, and a mixture of 40.0 parts of styrene and 40.0 parts of BA is used as a vinyl monomer using a dropping funnel. The solution was dropped and polymerized over 2 hours. After completion of dropping, the mixture was aged at the same temperature for 4 hours. Then, after cooling, 202.5 parts of PUD-1 (solid content 39.5%), which is the urethane polymer (I) specified in the present invention, prepared previously in Synthesis Example 5 was added and stirred for 10 minutes. After homogenization, the mixture was filtered through a 400 mesh wire mesh to obtain an aqueous dispersion of fine particles.

  In the measurement of the particle diameter by the light scattering method of the obtained aqueous dispersion of fine particles, there are two peaks near 50 nm and 220 nm, and the particle size distribution is not unimodal. It was not obtained. The average particle size as a whole was 138 nm. The solid content was 29.8%, the pH was 8.4, and the viscosity was 6.9 mPa · s. The number average molecular weight of the vinyl polymer as measured by GPC determined by polymerization was 179000, and the degree of dispersion was 2.95. This example was a sample in which the urethane polymer (I) was simply mixed without being combined in the polymerization step. This is referred to as CSE-1.

[Comparative Example 3: System not using urethane polymer (I)]
Using the same apparatus as in Example 1, 40.0 parts of ABP-1 which is the AB block copolymer (III) defined in the present invention of the solid previously prepared in Synthesis Example 1 was used as a neutralizing agent. 4.4 parts of DMAE and 274.7 parts of ion-exchanged water were charged, heated to 80 ° C. while flowing nitrogen gas, and dissolved by heating for 1 hour to form an aqueous solution. The pH of this solution was 8.5. After the temperature in the reaction vessel is lowered to 75 ° C., 1.0 part of KPS is added and dissolved as a polymerization initiator, and a mixture of 40.0 parts of styrene and 40.0 parts of BA is used as a vinyl monomer using a dropping funnel. The solution was dropped and polymerized over 2 hours. After completion of the dropwise addition, the mixture was aged at the same temperature for 4 hours, cooled, and filtered through a 400 mesh wire mesh to obtain an aqueous dispersion of fine particles.

  The average particle size of the obtained aqueous dispersion of fine particles by light scattering was 157 nm, and the particle size distribution was unimodal. The solid content was 30.1%, the pH was 8.6, and the viscosity was 4.5 mPa · s. The vinyl polymer (II) polymerized above had a number average molecular weight of 169400 as measured by GPC, and a dispersity of 3.29. This is a sample containing no urethane component in the fine particles. This is referred to as CSE-2.

Table 2 summarizes the compositions and physical properties of the polymer aqueous dispersions obtained in the above Examples and Comparative Examples.

[Example 7: Preparation of cyan pigment dispersion having polymer aqueous dispersion]
200 parts of an ammonia neutralized aqueous solution (solid content 20%) of ABP-1 which is the AB block copolymer (III) defined in the present invention obtained in Synthesis Example 1, 80 parts of diethylene glycol monobutyl ether, 320 of ion-exchanged water After mixing the parts to make a uniform solution, C.I. I. A mill base was prepared by adding 200 parts of Pigment Blue 15: 3 (copper phthalocyanine pigment, A220JC, manufactured by Dainichi Seika Kogyo Co., Ltd.) and mixing with a disper.

  Dispersion of the mill base prepared above at a peripheral speed of 10 m / s using a horizontal medium disperser “Dynomill 0.6 liter ECM type” (trade name, manufactured by Shinmaru Enterprises Co., Ltd., zirconia bead diameter 0.5 mm) For 2 hours to obtain a dispersion. Next, the obtained dispersion was centrifuged (7500 rpm, 20 minutes), filtered through a membrane filter having a pore size of 10 μm, and ion-exchanged water was added to obtain a dispersion having a pigment concentration of 15%. Hereinafter, this is referred to as a Plesian pigment dispersion. Next, 25 parts of the polymer aqueous dispersion AUE-1 obtained in Example 1 was added to and mixed with 100 parts of this Presian pigment dispersion, and the cyan pigment of this example having composite fine particles as defined in the present invention. A dispersion was obtained. The particle size distribution of the pigment particles contained in this dispersion was measured and found to be 102 nm. The viscosity of the dispersion measured with an E-type viscometer was 6.10 mPa · s.

[Comparative Example 4: Comparative cyan pigment dispersion]
AUE-1 used in Example 7 was carried out in the same manner except that it was changed to PUD-1, which is the urethane polymer (I) defined in the present invention, prepared in Synthesis Example 5, and a comparative cyan pigment dispersion was obtained. Obtained. When the particle size distribution of the pigment particles contained in this dispersion was measured, the average particle size was 102 nm. Further, the viscosity of the pigment dispersion measured with an E-type viscometer was 5.40 mPa · s.

[Examples 8 to 10: Preparation of magenta, yellow, and black pigment dispersions]
In place of the cyan pigment used in Example 7, C.I. I. Pigment Red 122 (dimethylquinacridone pigment, CFR-130P, manufactured by Dainichi Seika Kogyo Co., Ltd.), C.I. I. Pigment Yellow 74 (monoazo yellow pigment, Seika First Yellow 2016G, manufactured by Dainichi Seika Kogyo Co., Ltd.), C.I. I. Pigment black 7 (manufactured by Degussa, S-170) was used in the same manner as in Example 7 above, but for each color having AUE-1 as the polymer aqueous dispersion obtained in Example 1. A pigment dispersion was obtained. In the same manner as in Example 7, the particle size distribution of pigment particles contained in each dispersion obtained above was measured, and the average particle size (nm) was measured. Further, the viscosity of each pigment dispersion was measured in the same manner as in Example 7. Table 3 summarizes these results as the measurement results of the pigment dispersion immediately after production. In Table 3, the cyan pigment dispersion is also shown.

[Evaluation for each color pigment dispersion]
The storage stability of each of the color pigment dispersions of Examples 7 to 10 and Comparative Example 4 was evaluated by the following method. Specifically, each color pigment dispersion was stored at 70 ° C. for one week, and in the same manner as in Example 7, the average particle diameter, viscosity, and visual appearance of each pigment dispersion after storage were observed. The results are shown in Table 3.

  As shown in Table 3, the pigment dispersion of Comparative Example 4 containing a urethane emulsion had a particle size that increased after storage for 1 week at 70 ° C., and its appearance was cohesive and its viscosity increased. It was. On the other hand, it was confirmed that the pigment dispersions (emulsions) of the examples of the present invention were stable with no change in particle diameter, viscosity and appearance even after storage at 70 ° C. for 1 week.

[Example 11: Preparation of cyan inkjet ink (1)]
100 parts of the cyan pigment dispersion obtained in Example 7 and 50 parts of AUE-1 which is the polymer aqueous dispersion obtained in Example 1 as an emulsion binder, 15 parts of 1,2-hexanediol, and glycerin 30 3 parts, Surfinol 465 (trade name, manufactured by Air Products) and 105 parts of ion-exchanged water were mixed and sufficiently stirred, and then filtered through a membrane filter having a pore size of 10 μm. The cyan inkjet ink of this example Got. The viscosity of this inkjet ink was 2.62 mPa · s.

[Examples 12 to 14: Preparation of magenta, yellow and black inkjet inks]
Instead of the cyan pigment dispersion used in Example 11, the same magenta, yellow and black color pigment dispersions as obtained in Examples 8 to 10 were used, respectively. Each color ink-jet ink was prepared by the method. And the viscosity measurement of the obtained inkjet ink was performed, and the result was shown in Table 4.

[Examples 15 to 19: Preparation of inkjet ink in which polymer aqueous dispersion was changed]
The emulsion which is the polymer aqueous dispersion defined in the present invention, obtained in each of Examples 2 to 6, instead of the emulsion binder AUE-1 which is the polymer aqueous dispersion defined in the present invention used in Example 11. Cyan inkjet inks (2) to (6) were prepared in the same manner as in Example 11 except that binders AUE-2 to AUE-6 were used. And the viscosity measurement of each obtained inkjet ink was performed, and the result was shown in Table 4.

[Comparative Examples 5 to 7]
Instead of the cyan pigment dispersion obtained in Example 7 used in Example 11, the cyan pigment dispersion obtained in Comparative Example 4 was used, and the emulsion binder AUE-1 used in Example 11 was used. Instead, cyan inkjet ink (7) was prepared in the same manner as in Example 11 except that CSE-1 and CSE-2 obtained in Comparative Examples 2 and 3 and urethane emulsion PUD-1 obtained in Synthesis Example 5 were used. To (9) were prepared. And the viscosity measurement of each obtained inkjet ink was performed, and the result was shown in Table 4.

In Table 4, the viscosity measurement result of each ink measured about each ink for inkjet recording of Examples 11-19 and Comparative Examples 5-7 obtained as mentioned above was shown collectively.

[Evaluation of ink]
(Evaluation of ink ejection properties, printability of glossy paper and adhesion to glossy paper)
Each inkjet ink of Examples 11 to 19 and Comparative Examples 5 to 7 is filled in a cartridge, and using an inkjet printer “EM930C” (trade name) manufactured by Seiko Epson Corporation, glossy paper for inkjet manufactured by Konica Minolta Solid printing was performed on “Photolike QP” (trade name) in the high-speed printing draft mode. As a result, when the inkjet inks having the configurations of Examples 11 to 19 and Comparative Example 6 were used, the head was not clogged even after printing 100 sheets, and the prints were not blurred or streaked. It was confirmed to show the printing state.

  In contrast, when the inkjet inks of Comparative Examples 5 and 7 were used, 10 sheets were printed with the ink of Comparative Example 5 and 8 sheets were printed with the ink of Comparative Example 7, both of which were streaked in the print portion. There has occurred. Thereafter, streaks and fading gradually occurred, and printing was impossible on the 28th sheet with the ink of Comparative Example 5 and on the 21st sheet with the ink of Comparative Example 7. This is considered due to the low discharge stability of the urethane emulsion. On the other hand, the inks of Examples 11 to 19 and Comparative Example 6 were considered to have high particle stability due to the presence of the acrylic AB block copolymer in the composite fine particles, and exhibited excellent ejection stability. It is done.

  The print obtained by performing solid printing as described above was allowed to stand at room temperature for 24 hours, and then measured for 20 ° gloss using micro-TRI-gloss (manufactured by BYK), and the print portion was rubbed with a finger. Thereafter, the gloss measurement was performed again to determine whether there was a gloss reduction, and the gloss paper printability and adhesion of each ink were evaluated as gloss paper rubbing resistance.

  As a result, when the inks of Examples 11 to 19 and Comparative Examples 5 and 7 were used, there was almost no reduction in gloss and good abrasion resistance was obtained, but the ink obtained in Comparative Example 6 was not glossy. Decline was confirmed. From the results described above, it is considered that the acrylic emulsion containing no urethane polymer in the ink as in Comparative Example 6 has insufficient adhesion to the formed image and is inferior in abrasion resistance.

(Evaluation of adhesion in film prints)
Solid printing was similarly performed on a PET film using each ink and an inkjet printer similar to those used in the glossy paper printability evaluation described above. Then, each printed matter obtained is put in a dryer at 70 ° C. for 5 minutes to dry, and after making a grid-like cut with a cutter in the printed part, adhesive tape (registered trademark) is applied and peeled off at once. A test was conducted.

  As a result, when the inks of Examples 11 to 19 and Comparative Examples 5 and 7 were used, the printed part was not peeled off at all and showed good adhesion. On the other hand, in the ink obtained in Comparative Example 6, a part of the print portion was peeled off. The reason is considered that the acrylic emulsion containing no urethane component has insufficient adhesion to the base material, and thus has been peeled off.

  When the same test was performed using a vinyl chloride film and a surface-treated polyethylene film instead of the PET film, the same result as that obtained when the PET film was used was obtained.

(Evaluation of adhesion in fiber prints)
Solid printing was performed in the same manner on the cotton cloth for ink jet using the same ink and ink jet printer as those used in the above-mentioned evaluation of glossy paper printability. Then, each printed matter obtained was put in a dryer at 70 ° C. for 5 minutes and dried. The following test was performed as adhesive evaluation with respect to a fiber print. After drying, the optical density of the printed part was measured using an optical densitometer (trade name “Macbeth RD-914”, manufactured by Macbeth). Thereafter, the printed matter is put in a beaker containing ion-exchanged water and stirred with a magnetic stirrer for 10 hours, then the printed matter is taken out, dried in a dryer at 70 ° C. for 3 hours, and then the same method as described above. Then, the optical density was measured again to test whether the optical density decreased.

  As a result, in the case of prints formed using the inks of Examples 11 to 19 and Comparative Examples 5 and 7, the optical density was hardly lowered and good adhesion was exhibited. On the other hand, in the ink obtained in Comparative Example 6, the optical density was lowered. The acrylic emulsion containing no polyurethane component is considered to have lost color due to insufficient adhesion to cotton.

  From the above results, when the aqueous polymer dispersion of the present invention is used as an emulsion binder, an aqueous inkjet ink that has excellent continuous ejection stability, prints for various materials, and excellent adhesion and rub resistance can be obtained. It was confirmed that it could be provided.

  Examples of the use of the present invention include an inkjet ink to which a polymer aqueous dispersion containing composite fine particles essentially comprising three kinds of polymers characterizing the present invention is added. Although the ink contains resin fine particles, it can achieve a low viscosity of the ink, is excellent in both high-speed printability and ink re-dissolvability, and has good image adhesion to glossy paper, film, and fibers. It can be realized, can provide an ink-jet ink suitable for an ink-jet printing system compatible with high-speed printing, and future development is expected.

Claims (16)

Polymer comprising resin fine particles formed by complexing three types of polymers, urethane polymer (I), vinyl polymer (II), and AB block copolymer (III) containing methacrylic acid monomer as constituent components An aqueous dispersion,
The mass ratio of the three types of polymers (I) :( II) :( III) constituting the composite resin fine particles is 10-80: 10-80: 10-80,
The urethane polymer (I) is a urethane polymer that has an ionized anionic group in its structure and is dispersed in water.
The vinyl polymer (II) is obtained by polymerizing a vinyl monomer, and may have a cross-linked structure as necessary, and has a polystyrene-reduced number average molecular weight of 50,000 to 400,000 in a gel perchromatograph. Yes,
90% by mass or more of the AB block copolymer (III) is composed of a methacrylic acid monomer,
The polymer block of A is substantially insoluble in water, its number average molecular weight is 1000 to 10,000, and the molecular weight distribution is 1.5 or less,
The polymer block of B has methacrylic acid as at least a constituent monomer, an acid value of 50 to 300 mgKOH / g, and its number average molecular weight (number average of the polymer blocks of A from the number average molecular weight of the whole AB block copolymer) The molecular weight minus the molecular weight) is 1000-10000,
A polymer aqueous dispersion, wherein the AB block copolymer has a number average molecular weight of 2000 to 20000, a molecular weight distribution of 1.5 or less, and an acid value of 30 to 200 mgKOH / g.   2. The polymer aqueous dispersion according to claim 1, wherein the composite resin fine particles have an average particle diameter of 50 to 200 nm and a monomodal particle size distribution.   The methacrylic acid monomer, which is a component for forming the polymer block of A constituting the AB block copolymer (III), contains at least one of benzyl methacrylate or cyclohexyl methacrylate. Polymer water dispersion.   The urethane polymer (I) is a reaction product obtained by reacting an isocyanate component, a polyol component and / or a polymer polyol component, a dimethylolalkanoic acid component, and, if necessary, a diamine component as a chain extender. As the polymer polyol component, any one or more selected from the group consisting of polyether polyol, polycarbonate polyol, polysiloxane polyol and polyvinyl polyol is used, and the acid value of the polymer is 10 to 100 mgKOH / It is g, The polymer water dispersion of any one of Claims 1-3. It is a manufacturing method of the polymer water dispersion according to claim 1,
The urethane polymer (I) dispersed in water by neutralizing the anionic group with water in water, and water by neutralizing the carboxy group of methacrylic acid constituting the polymer block of B with water. The AB block copolymer (III) dispersed in is present, and in the presence of these two types of polymers, a radical polymerization initiator is used and a vinyl monomer is added to polymerize the vinyl. A method for producing a polymer aqueous dispersion, comprising obtaining a polymer (II) and combining three kinds of polymers to form the resin fine particles.   As the urethane polymer (I), an aqueous dispersion in which the anionic group is neutralized with an alkali and dispersed in water, and an average particle diameter by light scattering measurement is 10 to 100 nm, and the 3 6. The method for producing an aqueous polymer dispersion according to claim 5, wherein the resin fine particles obtained by complexing the seed polymer have an average particle size of 50 to 200 nm and a particle size distribution that is unimodal.   The alkali for neutralizing the anionic group is at least one of dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate, and neutralizes part or all of the anionic group Item 7. A method for producing an aqueous polymer dispersion according to Item 5 or 6.   The methacrylic acid monomer, which is a component for forming the polymer block of A constituting the AB block copolymer (III), contains at least one of benzyl methacrylate or cyclohexyl methacrylate. A method for producing a polymer aqueous dispersion according to item 1.   The polymer aqueous dispersion according to any one of claims 5 to 8, wherein the AB block copolymer (III) is obtained by using living radical polymerization using a polymerization initiating compound. Production method.   As the urethane polymer (I), the polymer obtained by reacting an isocyanate component, a polyol component and / or a polymer polyol component, a dimethylolalkanoic acid component, and, if necessary, a diamine component as a chain extender. And the polymer polyol component is any one or more selected from the group consisting of polyether polyols, polycarbonate polyols, polysiloxane polyols, and polyvinyl polyols. The method for producing a polymer aqueous dispersion according to any one of claims 5 to 9, wherein the formed polymer is used.   An aqueous solution comprising at least a pigment, a pigment dispersant, an organic solvent, water, and a binder component, wherein the binder component is the polymer water dispersion according to any one of claims 1 to 4. Pigment dispersion.   The aqueous pigment dispersion according to claim 11, wherein the pigment dispersant is the AB block copolymer (III) according to claim 1.   The organic solvent is diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, polyethylene The aqueous pigment dispersion according to claim 11 or 12, which is at least one selected from the group consisting of glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol and glycerin.   14. The aqueous pigment dispersion according to claim 11, wherein a mass ratio of the pigment and the polymer of the polymer aqueous dispersion that is the binder component is 50 to 300 parts with respect to 100 parts of the pigment. .   An ink for ink-jet recording comprising the polymer aqueous dispersion according to any one of claims 1 to 4.   An ink for inkjet recording, comprising the aqueous pigment dispersion according to any one of claims 11 to 14.