JP5552726B2 - Method for producing polymer fine particles - Google Patents

Description

  The present invention provides a method for producing polymer fine particles, in which the particle size can be set in a wide range of sizes and can achieve monodispersity with an excellent particle size distribution, and the weight produced by the production method. It relates to coalesced fine particles.

  One typical production method for producing polymer fine particles is a suspension polymerization method. This is a method in which droplets of a vinyl monomer are formed in water under an appropriate dispersion stabilizer, and polymer fine particles are synthesized using an appropriate oil-soluble initiator. Under normal conditions, polymer particles with a large particle size of several hundred μm to several mm are obtained, but the particle size distribution is governed by the breakup of the droplets during polymerization and the stochastic stochastic factors. Because it becomes very wide. Various improvement methods have been proposed, but all have improved, but have not yet achieved sufficient monodispersity.

  Another typical production method is an emulsion polymerization method. In the emulsion polymerization method, water-soluble radicals penetrate into surfactant micelles that have incorporated a hydrophobic monomer in an aqueous medium to form fine polymer particles, which further absorb and polymerize the monomer. grow up. By controlling the initial number of generated particles and the supply of the surfactant, polymer fine particles having a monodispersed particle size distribution can be produced. However, the size of the polymer fine particles obtained is limited to 0.01 to 1 μm because of the number of particles generated from the micelles and the limit of dispersion stability. Therefore, in order to produce monodisperse particles having an average particle diameter of several μm, it is necessary to use a seed emulsion polymerization method in which particles are grown using monodisperse fine particles synthesized by emulsion polymerization as seeds. However, the growth rate of the particles is low, and in order to obtain large particles, it is necessary to carry out several steps continuously, and there is a problem that monodispersity is not maintained and that it is disadvantageous in terms of cost.

  As an improvement of the seed emulsion polymerization method, a method of synthesizing monodisperse fine particles of several μm in one step by increasing the absorption efficiency of the monomer into the seed particles has been proposed. A method for producing micron-sized and highly monodisperse particles is proposed by increasing the swelling capacity of seed particles by absorbing a hydrophobic organic compound called so that the vinyl monomer is swollen and polymerized. Yes. However, this method has problems such as a complicated polymerization operation and a long swelling time.

  As a third method, there is a method called a dispersion polymerization method. The dispersion polymerization method is a monomer that is soluble in a medium in the state of a monomer in the presence of a dispersant dissolved in the medium, but the polymer formed by the polymerization is a monomer that is insoluble in the medium. In this method, polymerization is performed in a combination of solvents. In dispersion polymerization, polymerization starts from a completely homogeneous system, and the produced polymer is insoluble in a solvent, so that it immediately aggregates to produce unstable ultrafine particles. By combining the ultrafine particles, the relative density of the dispersing agent on the particle surface is increased to become stabilized particles. Polymer fine particles having excellent monodispersity can be obtained by growing the particles using the stabilized particles as nuclei. Dispersion polymerization can be carried out in a nonpolar medium or in a polar medium, and many combinations of solvents, monomers, and dispersants that can obtain polymer fine particles having excellent monodispersibility have been reported. Yes. For example, various methods have been proposed as a method for producing polymer fine particles (so-called non-aqueous polymer dispersion) stably dispersed in a polymer dispersion stabilizer in an organic solvent mainly composed of aliphatic hydrocarbons. Yes.

  These methods use a partial stabilizer consisting of a second segment that is not solvated in an organic solvent but associates with or is anchored to the dispersed polymer particles. It consists of forming dispersed polymer particles and then crosslinking the particles.

  As a representative example of the above dispersion stabilizer, a solvation component that is a self-condensate of 12-hydroxystearic acid is graft-polymerized or block-polymerized with a non-solvation component that is a polymer chain mainly composed of methyl methacrylate. Things.

  On the other hand, polyacrylic acid, polyvinyl pyrrolidone (hereinafter referred to as PVP), and hydroxypropyl cellulose (hereinafter referred to as HPC) are used as the dispersant in the polar solvent. For example, Patent Document 1 discloses that polymethyl methacrylate (hereinafter referred to as PMMA) having a coefficient of variation (hereinafter referred to as CV value) of 7.9% by using PVP as a dispersant in dispersion polymerization in a specific polar solvent. It is disclosed that fine particles can be obtained. Even in a dispersant such as PVP, it is known that fixing to the particle surface by a grafting reaction with a monomer during polymerization contributes to an improvement in dispersion stability. In some cases, the polymerization stability and monodispersity are insufficient.

  Therefore, it has been reported that a macromonomer type dispersant is used for the purpose of more positively utilizing the particle stabilization effect by grafting (for example, Non-Patent Documents 1, 2, 3, 4 and the like). reference). Furthermore, in Patent Document 2, it is not a block or graft polymer composed of two segments, but has a functionality with these groups on the hydroxyl group or carboxyl group of 12-hydroxystearic acid self-condensate that is a solvating component. A macromonomer introduced with an average of about 1.0 polymerizable unsaturated bond per molecule by reacting a polymerizable unsaturated monomer having a functional group such as an epoxy group or an isocyanate group is used as a dispersion stabilizer. There has been proposed a method for producing a polymer fine particle dispersion using the above as it is.

  In addition, a vinyl monomer copolymer (for example, an acrylic copolymer having a solubility parameter of 9.0 or less) having a specific composition that dissolves in an organic solvent mainly composed of aliphatic hydrocarbons is used. A method for producing a polymer fine particle dispersion using a macromonomer introduced with an average of about 1.0 polymerizable double bonds per molecule as a dispersion stabilizer has also been proposed (see, for example, Patent Document 3). However, none of them describes the monodispersity of the polymer fine particles, and it cannot be said to be sufficient to obtain polymer fine particles having good monodispersibility.

  Non-Patent Document 1 reports the dispersion polymerization of MMA in a water / ethanol solvent using a polyethylene glycol macromonomer having a methacryloyl group at the terminal as a dispersant. As described in Table 1 on page 2028, it has been reported that PMMA particles having a particle diameter as small as 0.1 to 0.2 μm can be obtained, but the monodispersity is not sufficient.

  Non-Patent Document 2 reports the dispersion polymerization of MMA in a water / methanol solvent using a polyoxazoline macromonomer having a styryl group at the terminal as a dispersant. As shown in FIG. 2 on page 142 and Table 1, micron-sized PMMA fine particles have been synthesized. It has been reported that monodispersity is good at a limited macromonomer concentration, but the monodispersity is greatly affected by changes in macromonomer concentration.

  Non-Patent Document 3 reports the emulsion / dispersion polymerization of MMA in a water / ethanol solvent using a polymethacrylic acid macromonomer having a vinylbenzyl group at the terminal as a dispersant. As shown in Table 1 on page 2854, PMMA particles having a particle size of 0.33 to 3 μm have been synthesized, but the monodispersity is not sufficient.

  Non-Patent Document 4 reports on the influence of solvent pH in the dispersion polymerization of MMA in water / ethanol solvent using a polyacrylic acid macromonomer having a vinylbenzyl group at the terminal as a dispersant. As shown in Table 1 on page 641, particles having excellent monodispersibility were synthesized in the pH range of 4 to 13, but the particle diameters were all 0.4 μm or less, and micron-sized particles were obtained. It is not done.

Patent Document 4 discloses a macromonomer having a specific terminal structure, that is, (M) _n CX = CH ₂ , where M is a monomer unit, n is a degree of polymerization, and X is a polar group. It is shown that monodisperse particles having a particle diameter of 1 to 10 μm can be obtained by dispersion polymerization by using as a dispersant. However, this macromonomer is derived from its terminal structure and has a very low degree of homopolymerization, in other words, it is extremely low in copolymerization with general vinyl monomers and vinyl copolymers as compared with the conventional macromonomer. In some cases, sufficient polymerization stability could not be maintained.

As described above, in the dispersion polymerization using the conventional macromonomer, it was difficult to obtain polymer fine particles with a wide particle size range and excellent monodispersity.
JP-A-4-23804 Japanese Patent Laid-Open No. 62-195008 JP-A-57-177068 JP 2004-149469 A J. et al. Appl. Polym. Sci. , 39.2027 (1990) Proc. Japan Acad. , 67, Ser. B, 140 (1991) Polymer, 37, 2853 (1996). Macromol. Rapid Commun. , 18, 639 (1997)

  The present invention solves the above-mentioned problems of the prior art, and easily and stably polymer fine particles having excellent monodispersity of particle size distribution in a relatively large and wide range of particle sizes. It is an object to provide a production method for obtaining the polymer fine particles produced by the method.

  As a result of repeated studies on a production method for easily and stably obtaining polymer fine particles having excellent monodispersibility in particle size distribution, the present inventors have determined that a vinyl monomer is a specific dispersant. In the presence, specifically, by using a macromonomer having a specific structure as a dispersant, the vinyl monomer and the dispersant are dissolved, but the resulting polymer is polymerized in a solvent that does not substantially dissolve. The inventors have found that the above-described problems can be solved, and have completed the present invention.

That is, in the present invention, 100 parts by weight or less of the vinyl monomer A and 0.01% by weight or more of the vinyl polymer B with respect to the vinyl monomer A are dissolved in 100 parts by weight of the polymerization solvent. In the polymerization solution, the vinyl monomer A is polymerized to produce polymer fine particles insoluble in the polymerization solvent , wherein the polymerization solvent is a hydrophilic solvent, The number average molecular weight of the polymer B is 3000 or more, and the value of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) measured by gel permeation chromatography is 1. A polar functional group X that is less than .8 and is at least one selected from the group consisting of a carboxyl group, a hydroxyl group, an epoxy group, an amino group, an amide group, a silyl group, an acetylacetonato group, and a mercapto group , vinyl The proportion of the structural unit having the polar functional group X among the structural units derived from the monomers constituting the main chain of the polymer B is 1 to 100 mol%, and the polar functional group X is at least per molecule of the vinyl polymer B. 0.8 or more and a carbon-carbon double bond represented by the following general formula 1 and / or a carbon-carbon double bond represented by the general formula 2 The present invention relates to a method for producing polymer fine particles characterized by having a group Z at one or more molecular terminals.

（式中、Ｒ１、及びＲ２は、水素、または、炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。また、Ｒ３は、直接結合、又は炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。）
好ましい実施態様は、前記ビニル系重合体Ｂの主鎖が、ラジカル重合、より好ましくはリビングラジカル重合、特に好ましくは原子移動ラジカル重合により製造されてなる主鎖である重合体微粒子の製造方法とすることである。

(In the formula, R1 and R2 represent hydrogen or a hydrocarbon group optionally containing an aromatic ring having 1 to 20 carbon atoms. R3 represents a direct bond or an aromatic group having 1 to 20 carbon atoms. Represents a hydrocarbon group which may contain a ring.)
A preferred embodiment is a method for producing polymer fine particles in which the main chain of the vinyl polymer B is a main chain formed by radical polymerization, more preferably living radical polymerization, particularly preferably atom transfer radical polymerization. That is.

In a preferred embodiment, the main chain of the vinyl polymer B is selected from the group consisting of (meth) acrylic monomers, acrylonitrile monomers, aromatic vinyl monomers, fluorine-containing vinyl monomers, and silicon-containing vinyl monomers. It is a manufacturing method of polymer fine particles which are main chains obtained by polymerizing 60% or more of one or more monomers.

  A preferred embodiment is a method for producing polymer fine particles in which R1 in the group Z containing a carbon-carbon double bond is hydrogen and / or a methyl group.

  A preferred embodiment is a method for producing polymer fine particles in which R2 in the group Z containing a carbon-carbon double bond is hydrogen and / or a methyl group.

  A preferred embodiment is that the vinyl polymer B is a method for producing polymer fine particles containing a hydrophobic monomer unit as a constituent monomer unit.

  A preferred embodiment is the production of polymer fine particles in which the polar functional group X is a carboxyl group and at least a part of the carboxyl group is neutralized with an alkali during the polymerization of the vinyl monomer A. It is to be a method.

  The present invention also relates to polymer fine particles produced by the method for producing polymer fine particles of the present invention.

  A preferred embodiment is to make polymer fine particles having a volume average particle diameter of 0.05 to 20 μm and a CV value of 30% or less.

  A preferred embodiment is to make polymer fine particles having a volume average particle diameter of 1 to 20 μm.

  According to the method for producing polymer fine particles of the present invention, polymer fine particles excellent in monodispersity of particle size distribution can be produced easily and stably in a relatively large and wide range of particle sizes. be able to.

  Hereinafter, the polymer fine particles of the present invention will be described in detail.

(Polymer fine particles)
The polymer fine particles of the present invention preferably have a number average particle diameter of 0.05 μm to 20 μm and a CV value of 30% or less as an index of monodispersity, although the average particle diameter is relatively large. , Having extremely excellent monodispersity of particle size distribution. More preferably, the number average particle diameter is 1 to 20 μm.

  In the present invention, the average particle diameter and the CV value are measured by electron microscope observation of about 200 polymer fine particles, and the particle diameter (di) is calculated from the measurement results according to the following formulas 1 to 3. Is the value to be

但し、数式１〜３において、ｄｎは数平均粒子径、ｄｖは体積平均粒子径、ｎｉは粒子径がｄｉの微粒子の個数である。また、数式３において、σは標準偏差であり、以下の数式４で表される。

In Equations 1 to 3, dn is the number average particle diameter, dv is the volume average particle diameter, and ni is the number of fine particles having a particle diameter di. In Equation 3, σ is a standard deviation and is expressed by Equation 4 below.

（用途）
本発明の重合体微粒子は、上述のように比較的大きな、また、幅広い範囲の粒子径において、粒子径分布の分散性に優れているため、液晶表示素子用スペーサ、液晶表示用光拡散フィルム等の光拡散剤、導電性微粒子、カラム用充填剤、診断薬用の担体、樹脂改質剤、樹脂／塗料分野における艶消し剤、化粧品用添加剤、及び電子複写機分野におけるトナー用材料等の幅広い分野に好適に用いられうる。また、上記用途に使用される微粒子を製造するためのシード粒子としても有用である。

(Use)
The polymer fine particles of the present invention are relatively large as described above, and are excellent in dispersibility of the particle size distribution in a wide range of particle sizes. Thus, spacers for liquid crystal display elements, light diffusion films for liquid crystal displays, etc. A wide range of light diffusing agents, conductive fine particles, column fillers, diagnostic carriers, resin modifiers, matting agents in the resin / paint field, cosmetic additives, and toner materials in the field of electronic copiers, etc. It can be suitably used in the field. Moreover, it is useful also as a seed particle for manufacturing the microparticles | fine-particles used for the said use.

  Hereinafter, the method for producing polymer fine particles of the present invention will be described in detail.

(Production method)
In the method for producing polymer fine particles of the present invention, a vinyl monomer is produced in the presence of a specific vinyl polymer that functions as a dispersant, while the vinyl monomer and the vinyl polymer are dissolved. The polymer to be polymerized is one that is polymerized in a polymerization solvent that does not substantially dissolve. That is, the vinyl monomer A and the vinyl polymer B are dissolved in a polymerization solvent, and the vinyl monomer A is polymerized to produce polymer fine particles insoluble in the polymerization solvent. This is a method for producing polymer fine particles.

  That is, the method for producing polymer fine particles of the present invention is a method for producing micron-sized monodisperse polymer fine particles by a dispersion polymerization method. In dispersion polymerization, stabilizing particles are formed at a stage where the reaction rate of the vinyl monomer is as low as possible, that is, at an early timing of the polymerization, and the stability of the stabilizing particles is completed during the growth process of the stabilizing particles. In order to obtain excellent monodispersity, it is preferable that the generation of new particles is sufficiently suppressed, and in the method for producing polymer fine particles of the present invention, a high function as a dispersant. Since these can be achieved by the presence of the vinyl polymer B having, polymer fine particles having a wide range and excellent in monodispersibility can be stably and easily produced with good reproducibility.

  Specifically, in the production method of the present invention, for example, a reaction vessel is charged with a polymerization solvent, a vinyl polymer B that functions as a dispersant, a part or all of the vinyl monomer A, and an additive as appropriate. After substituting the reaction vessel atmosphere with an inert gas, the temperature is raised while performing appropriate stirring, and when the temperature is stabilized, a polymerization initiator is added to carry out the polymerization. As described above, after the polymerization is started, the vinyl monomer can be divided or continuously charged. At this time, in order to carry out the polymerization in a high polymerization rate region, usually 4 to 40 hours of polymerization time is required, but the polymerization may be stopped at a desired particle size or particle size distribution, or a polymerization initiator. The polymerization rate may be increased by additionally adding. Further, the present invention includes growing the polymer fine particles by carrying out the above reaction in the presence of polymer fine particles having a particle size distribution smaller than the target particle size and having a small particle size distribution.

  Examples of the additive include a dispersant, an emulsifier, a chain transfer agent, a crosslinking agent, a water-soluble polymer compound, and a poorly water-soluble substance.

(Polymer fine particle recovery method)
Polymer fine particles after completion of polymerization are separated by operations such as sedimentation, centrifugation, decantation, etc., dried and recovered, dehydrated after completion of polymerization, dried and recovered, and an acid or salt is added. In general, the polymer fine particles are aggregated, and the resulting slurry is recovered as an aggregate of polymer fine particles by a method of dehydrating and drying, or a spray drying method.

(Neutralization with alkali)
The polar functional group X of the vinyl polymer B which is a dispersant in the present invention is preferably a carboxyl group. In this case, at the time of polymerization of the vinyl monomer A, at least a part of the carboxyl group is present. Neutralization with an alkali is preferable because a part of the carboxyl group becomes a carboxy anion and can provide a particle stabilizing effect due to electrostatic repulsion. In particular, when the solvent used in the production of the polymer fine particles is an aqueous solution of a hydrophilic organic solvent described later, the effect is great, a combination of both is particularly preferable, and extremely excellent polymerization stability is realized.

  Examples of the alkali used for neutralization include ammonia, a low-boiling amine compound having a boiling point of 140 ° C. or lower, sodium hydroxide, and sodium carbonate. Examples of the low boiling point amine compound include trimethylamine, diethylamine, triethylamine, dimethylethylamine, N-methylmorpholine, t-butanolamine, morpholine, and dimethylethanolamine. The neutralization of the vinyl polymer B with alkali may be partial neutralization. A preferable neutralization rate is 50 to 100%. The neutralization rate of 100% includes a case where an alkali is excessively present.

(Polymerization solvent)
The polymerization solvent is not particularly limited as long as the above conditions are satisfied, and may be selected according to the type of vinyl monomer and vinyl polymer used and the size of the target polymer fine particles. Well, a hydrophobic organic solvent, a hydrophilic organic solvent, or an aqueous solution of a hydrophilic organic solvent can be selected. Hereinafter, the hydrophilic organic solvent and the aqueous solution of the hydrophilic organic solvent are collectively referred to as a hydrophilic solvent.

  In the present invention, the polymerization solvent is preferably a hydrophilic solvent, and the polymerization stability can be improved by appropriately combining with a vinyl polymer B having a polar functional group Z that functions as a dispersant described later. Therefore, the particle diameter and particle diameter distribution of the polymer fine particles and the molecular weight of the polymer molecules constituting the polymer fine particles can be highly controlled.

  More preferably, the polymerization solvent is an aqueous solution of a hydrophilic organic solvent. By making the polar functional group Z a hydrophilic group, particularly an ionic group, the vinyl polymer B is highly dispersed and stabilized. Can be granted. That is, by changing the mixing ratio of the hydrophilic organic solvent and water, it becomes possible to make the combination of the above-described polymerization solvent and vinyl polymer B more appropriate, so that the polymerization stability is improved. It can be improved. In addition, an aqueous solution of a hydrophilic organic solvent can reduce the risk of ignition, explosion, and the like, and has a low environmental load.

  Particularly preferably, the polymerization solvent is an aqueous solution of a lower alcohol, and a preferable mixing ratio is lower alcohol: water = 99.5: 0.5 to 50:50 by weight. When the weight ratio of the lower alcohol exceeds 99.5, coalescence between the produced polymer fine particles may occur, and when it is less than 50, the produced fine particles may be too small.

  Such lower alcohol is preferably at least one selected from the group consisting of methyl alcohol, ethyl alcohol, and isopropyl alcohol.

  In addition, organic solvents other than alcohols and ether alcohols can coexist within a range in which the produced polymer fine particles are not dissolved in order to control the particle size, particle size distribution, and polymerization stability.

  Further, as described above, when a polymerization solvent is used as a mixed solvent, the generated solvent is changed by changing the type and composition of the mixed solvent at the time of initiation of polymerization, during polymerization, and at the end of polymerization. The particle size, particle size distribution, etc. of the coalesced particles can be adjusted.

Furthermore, the polymerization is carried out in the state where inorganic ions such as SO ₄ ²⁻ , NO ₃ ⁻ , PO ₄ ³⁻ , Cl ⁻ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , etc. are present in the polymerization solvent. This is also preferable from the viewpoint of controlling the polymerization stability.

  Examples of the hydrophobic organic solvent include hydrocarbons such as hexane, heptane, octane, petroleum ether, cyclohexane, benzene, toluene, and xylene. These hydrophobic organic solvents are, for example, hydrophilic as described above. It can also be used as an organic solvent used in combination with a solvent, and other organic solvents that can be used in combination include halogenated hydrocarbons such as carbon tetrachloride, trichloroethylene, and tetrabromoethane, ethyl ether, Ethers such as dimethyl glycol, trioxane and tetravidrofuran, acetals such as methylal and diethyl acetal, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexane, butyl formate, butyl acetate, ethyl propionate, and Such as cellosolve acetate Ester ethers, formic acid, acetic acid, and acids such as propionic acid, nitro-propene, nitrobenzene, dimethylamine, monoethanolamine, pyridine, dimethyl sulfoxide, and sulfur / nitrogen-containing organic compounds such as dimethyl formamide, and the like.

  The hydrophilic organic solvent means an organic solvent having a solubility in water at 20 ° C. of 2% by weight or more, and types thereof include alcohols and ether alcohols. Or as a mixed solvent in which two or more are mixed.

  Examples of the alcohols include methyl alcohol, ethyl alcohol, modified ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, benzyl alcohol, Examples include cyclohexanol, furallyl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, glycerin, and diethylene glycol.

  Examples of the ether alcohols include tilcellosolve, cellosolve, isopropylpyrrolocellosolve, butylcellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether.

(Vinyl monomer A)
As the vinyl monomer A used in the present invention, a polymerization generally used in polymerization is possible as long as it is soluble in the polymerization solvent and the polymer is insoluble in the polymerization solvent. For example, a group consisting of (meth) acrylic acid alkyl ester monomers, aromatic vinyl monomers, vinyl cyanide monomers, vinyl acetate, and vinyl chloride One or more kinds of the above can be used, and a small amount of anionic polymerizable monomer and / or a relatively highly polar vinyl monomer such as a cationic polymerizable monomer is copolymerized. Thus, the polymerization stability of the polymer fine particles and the triboelectric charging property of the powdered polymer fine particles can be adjusted.

(Amount of vinyl monomer A)
In the present invention, the proportion of vinyl monomer A used is 100 parts by weight or less, preferably 60 parts by weight or less, more preferably 30 parts by weight or less, based on 100 parts by weight of the polymerization solvent. If the ratio of the vinyl monomer A to the polymerization solvent is too large, the degree of swelling of the produced polymer particles due to the medium (polymerization solvent in which the unreacted monomer is dissolved) becomes too large, and the vinyl polymer B is contained. In some cases, the polymer fine particles may agglomerate by overcoming the stabilization effect by the dispersant, and if too much, the solubility of the produced polymer in the medium becomes too high and particles can be formed. In some cases, it becomes a lump. The vinyl monomer A is initially charged all at once, polymerized by batch polymerization operation, polymerized by divided charging, or continuously fed to the reactor and polymerized by semi-batch polymerization operation. Although it is good, when the amount of the vinyl monomer A relative to the polymerization solvent is large, it is preferable to select a semi-batch polymerization operation.

(Example of vinyl monomer A)
Examples of the (meth) acrylic acid alkyl ester monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Representative examples include n-octyl and 2-ethylhexyl (meth) acrylate. Here, in this specification, for example, (meth) acryl means acrylic and / or methacryl unless otherwise specified.

  Typical examples of the aromatic vinyl monomer include styrene, α-methylstyrene, chlorostyrene, and chloromethylstyrene.

  Representative examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, ethacrylonitrile, and the like.

  Examples of the anionic polymerizable monomer include a carboxyl group-containing monomer, an acid anhydride-containing monomer, a phosphate group-containing monomer, and a sulfonic acid group-containing monomer.

  Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monobutyl itaconate, and monobutyl maleate.

  Examples of the acid anhydride-containing monomer include maleic anhydride.

  Examples of the phosphate group-containing monomer include acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, and 3-chloro-2-acid phosphooxypropyl methacrylate.

  Examples of the sulfonic acid group-containing monomer include 2-acrylamide, 2-methylpropanesulfonic acid, 2-sulfoethyl methacrylate, and the like.

  Examples of the cationic polymerizable monomer include nitrogen-containing alkyl (meth) acrylate, and more specifically, for example, dimethylaminoethyl acrylate and diethylaminoethyl methacrylate.

(Dispersant, emulsifier)
The dispersant in the present application is a compound having amphiphilic properties with respect to a polymer and a dispersion medium that is a polymerization solvent, and a component having affinity with the polymer is anchored to the polymer fine particles, Polymer fine particles by increasing the relative density on the surface of the polymer fine particles and forming a thick solvation layer by extending the component having affinity for the dispersion medium from the surface of the polymer fine particles to the dispersion medium phase It has the effect | action which stabilizes.

  In the present invention, in order to further improve the stability of the polymer fine particles in the polymerization solvent and to narrow the particle size distribution, it is used in combination with the vinyl polymer B functioning as a dispersant in addition to other known dispersions. Agents, emulsifiers, and / or water-soluble polymer compounds and poorly water-soluble substances can be used without particular limitation.

  Examples of the dispersant include homopolymers such as polyvinylpyrrolidone. However, when such a homopolymer is used alone as a dispersant, anchors to the polymer particles may be insufficient, the stability of the growing particles may be insufficient, and monodispersity may be difficult to obtain. , Problems such as the formation of aggregates may occur.

  Moreover, as said dispersing agent, it has copolymerizability with a vinyl monomer other than the vinyl polymer B as disclosed in Non-Patent Documents 3, 4, 5, and 6 described above, for example. There are macromonomers. However, when such a macromonomer other than the vinyl polymer B is used alone as a dispersant, these conventional macromonomers do not have the excellent characteristics of the vinyl polymer B described later. In some cases, it is difficult to produce polymer fine particles having a wide particle diameter and excellent in monodispersion because of low copolymerizability to polymer fine particles and insufficient dispersion protection ability.

(Vinyl polymer B)
The vinyl polymer B used in the present invention is a so-called macromonomer, and further,
(1) Since the composition of the main chain polymer can be widely selected and the structure can be controlled including the block structure, the introduction amount and position of hydrophilic groups such as carboxyl groups and hydrophobic monomer units can be easily controlled. (2) The ability to strictly control the structure such as molecular weight, molecular weight distribution, etc., so that a material excellent in uniformity of desired physical properties can be obtained;
(3) Since there is a high degree of freedom in selecting the structure of the terminal unsaturated group, the reactive unsaturated group can be obtained, and the introduction rate into the main chain polymer can be made extremely high. The characteristics that a high copolymerization property to the system monomer A and / or polymer fine particles can be obtained,
It is something that makes use of.

  As a result, such a vinyl polymer B can be sufficiently anchored to the polymer fine particles, can have a high dispersion protection capability, and further exhibits a uniform dispersibility function. Therefore, a dispersant for easily and stably obtaining polymer fine particles having a function as an excellent dispersant, having a wide particle size and excellent in monodispersion. Become. In addition, since the vinyl polymer B according to the present invention is a macromonomer having a highly reactive functional group, it is possible to efficiently obtain polymer fine particles with a smaller amount of macromonomer.

  Such a vinyl polymer B used in the present invention is soluble in the polymerization solvent and specified by the following conditions, and is important for the polymerization stability during the production of polymer fine particles. By playing a role, it contributes to the control of the particle size and particle size distribution of the polymer fine particles.

  That is, the vinyl polymer B used in the present invention has a number average molecular weight of 3000 or more, and a ratio between the weight average molecular weight (Mw) and the number average molecular weight (Mn) measured by gel permeation chromatography. The value of (Mw / Mn) is less than 1.8, has a polar functional group X, and has a group Z containing a carbon-carbon double bond of a specific structure at one or more molecular ends.

(Amount of vinyl polymer B used)
In the present invention, the proportion of the vinyl polymer B used is 0.01 parts by weight or more with respect to 100 parts by weight of the vinyl monomer A, that is, 0.01% by weight or more with respect to the vinyl monomer A. Is necessary for exhibiting the function as the dispersant, and is preferably 100 parts by weight or less, more preferably 0.1 to 20 parts by weight. If the amount of the vinyl polymer B used is less than 0.01 parts by weight, the function as a dispersant may not be sufficiently achieved. If it exceeds 100 parts by weight, the viscosity of the polymer system may increase. The particle size may become too small. As described above, since the vinyl polymer B according to the present invention is a macromonomer having a highly reactive functional group, it is possible to efficiently obtain polymer fine particles with a small amount of macromonomer. In general, the cost of such a macromonomer, that is, the vinyl polymer B according to the present invention, is 0.1 to 2.3 parts by weight.

(Number average molecular weight and molecular weight distribution)
The number average molecular weight of the vinyl polymer B used in the present invention is required to be 3000 or more in order to exhibit the function as a dispersant, and from the viewpoint of sufficiently ensuring the solubility in the polymerization solvent. It is preferably 1,000,000 or less, more preferably 5,000 to 500,000, and particularly preferably 7,000 to 100,000 from the viewpoint of the polymerization stabilization ability.

  Further, the molecular weight distribution of the vinyl polymer B used in the present invention, that is, the ratio of the weight average molecular weight and the number average molecular weight measured by gel permeation chromatography is such that the production conditions of the polymer fine particles are uniform at each production site. Therefore, it is important that the ratio is less than 1.8, preferably less than 1.7, more preferably less than 1.5, and still more preferably less than 1.3. In the GPC measurement in the present invention, chloroform is usually used as the mobile phase, the measurement is performed with a polystyrene gel column, and the number average molecular weight and the like can be determined in terms of polystyrene.

(Polar functional group X)
The vinyl polymer B used in the present invention has a polar functional group X in order to form a more effective solvation layer, particularly when the solvent used in the production of polymer fine particles is the above-mentioned hydrophilic solvent. It is preferable to have.

  Although it does not specifically limit as said polar functional group X, For example, 1 or more types chosen from the group which consists of a carboxyl group, a hydroxyl group, an epoxy group, an amino group, an amide group, a silyl group, an acetylacetonato group, a mercapto group, etc. And more preferably a carboxyl group.

  The content of the vinyl polymer B of the polar functional group X can be appropriately determined according to the required characteristics, that is, the necessary polymerization stabilization ability, and is not particularly limited. Of the constituent units derived from the monomers constituting the main chain, the proportion of the constituent units having the polar functional group X is preferably 1 to 100 mol%, more preferably 2 to 90 mol%, and more preferably 5 to 80 mol % Is more preferable, and 10 to 70 mol% is particularly preferable. Moreover, it is preferable that at least 0.8 or more are contained per molecule of the vinyl polymer B.

  The position of the polar functional group X in the vinyl polymer B is not particularly limited, but may be at the molecular end or in the molecular chain. When it exists in a molecular terminal, it is more preferable to arrange | position to the terminal opposite to group Z containing a carbon-carbon double bond. When they are in the molecular chain, they may be arranged randomly, or may be arranged in blocks or gradients.

(Group Z containing a carbon-carbon double bond)
The group Z containing a carbon-carbon double bond at the molecular end of the vinyl polymer B used in the present invention is not particularly limited, but a group represented by the general formula 1 is preferable. Among these, those in which R1 is hydrogen or a methyl group are particularly preferable because they have high copolymerizability with a vinyl monomer.

（式中、Ｒ１は水素、または炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。）
また本発明で用いられるビニル系重合体Ｂの末端の炭素−炭素二重結合を含有する基Ｚは、一般式２で表される基も好適に用いることができる。この中でも、Ｒ２が水素またはメチル基であるものがビニル単量体と高い共重合性を有するため、特に好ましい。またＲ３は直鎖状でもよいし、分岐していてもよい。また環構造を有していてもよいし、芳香環を含んでいてもよいが、ビニル単量体との共重合性の面から、直鎖状が好ましい。

(In the formula, R 1 represents hydrogen or a hydrocarbon group which may contain an aromatic ring having 1 to 20 carbon atoms.)
In addition, as the group Z containing a carbon-carbon double bond at the terminal of the vinyl polymer B used in the present invention, a group represented by the general formula 2 can also be suitably used. Among these, those in which R2 is hydrogen or a methyl group are particularly preferable because they have high copolymerizability with a vinyl monomer. R3 may be linear or branched. Moreover, although it may have a ring structure and may contain an aromatic ring, a linear form is preferable from the surface of copolymerizability with a vinyl monomer.

（式中、Ｒ２は水素、または炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。またＲ３は直接結合または炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。）
前記炭素−炭素二重結合を含有する基Ｚを有することにより、ビニル系重合体Ｂは、ラジカル共重合性を有し、重合体微粒子の製造において、ビニル単量体Ａと共重合可能であり、共重合した場合には、ビニル単量体Ａとグラフト、及び／又は、ブロック共重合体を生成する。また、前記炭素−炭素二重結合を含有する基Ｚを、分子末端に有することにより、ビニル系重合体Ｂが重合体微粒子表面から溶媒に対して広がりやすいため、重合安定性を高めることができる。

(In the formula, R2 represents hydrogen or a hydrocarbon group which may contain an aromatic ring having 1 to 20 carbon atoms. R3 represents a carbon atom which may contain a direct bond or an aromatic ring having 1 to 20 carbon atoms. Represents a hydrogen group.)
By having the group Z containing the carbon-carbon double bond, the vinyl polymer B has radical copolymerizability, and can be copolymerized with the vinyl monomer A in the production of polymer fine particles. When copolymerized, a vinyl monomer A and a graft and / or a block copolymer are produced. In addition, by having the group Z containing the carbon-carbon double bond at the molecular end, the vinyl polymer B tends to spread from the surface of the polymer fine particles to the solvent, so that the polymerization stability can be improved. .

  By these things, the vinyl polymer B of this invention can exhibit the performance as a very outstanding dispersing agent.

  The group Z containing a carbon-carbon double bond present at the molecular terminal is 0.5 to 10 in average number per molecule of the vinyl polymer B from the viewpoint of polymerization stabilization ability. Are preferably used. The average number is more preferably 0.5 to 1.5, still more preferably 0.6 to 1.4, and particularly preferably 0.7 to 1.3.

(Vinyl polymer B main chain)
The main chain of the vinyl polymer B used in the present invention needs to have a monomer composition selected so that the vinyl polymer B is dissolved in the polymerization solvent. There may be branching.

(Method for synthesizing main chain of vinyl polymer B)
The polymerization method for constructing the main chain of the vinyl polymer B used in the present invention is not particularly limited, but radical polymerization is preferred, living radical polymerization is more preferred, atom transfer radical polymerization is particularly preferred, and most preferred. Is an atom transfer radical polymerization using a transition metal catalyst having copper as a central metal as a catalyst.

  Radical polymerization is generally considered to be difficult to control because the polymerization rate is high and a termination reaction due to coupling between radicals is likely to occur. However, although living radical polymerization and atom transfer radical polymerization are radical polymerizations, a termination reaction hardly occurs and a polymer having a narrow molecular weight distribution (Mw / Mn is about 1.1 to 1.5) is obtained. The molecular weight can be freely controlled by the charge ratio of the initiator.

  Therefore, the vinyl polymer B having a main chain polymerized by the above-described polymerization method has a narrow molecular weight distribution, a low viscosity, and a monomer having a specific functional group can be used at almost any position of the vinyl polymer B. Therefore, it is possible to make the combination of the polymerization solvent, the vinyl monomer A, and the polymer fine particles more suitable, and it is possible to introduce a specific functional group at the terminal. Therefore, the polymerization stability can be further improved.

  In the narrow sense, living polymerization refers to polymerization in which the terminal always has activity and the molecular chain grows, but in general, the terminal is inactivated and the terminal is activated. It also includes pseudo-living polymerization that grows in an equilibrium state. The definition of living polymerization in the present invention includes pseudo-living polymerization. This living polymerization method, particularly the atom transfer radical polymerization method, is described in, for example, Journal of American Chemical Society (J. Am. Chem. Soc.) 1995, 117, 5614, Macromolecule. Macromolecules, 1995, 28, 7901, Science 1996, 272, 866, WO 96/30421, or WO 97/18247, or Sawamoto et al., Macromolecules (Macromolecules). The method described in 1995, 28, 1721, Unexamined-Japanese-Patent No. 2000-44626, or Unexamined-Japanese-Patent No. 2000-191728 can be used.

(Main chain of vinyl polymer B)
The vinyl-based monomer constituting the main chain of the vinyl-based polymer B used in the present invention is not particularly limited, and various types can be used. For example, a (meth) acrylic acid-based monomer, Styrene monomers, fluorine-containing vinyl monomers, silicon-containing vinyl monomers, maleimide monomers, nitrile group-containing vinyl monomers, amide group-containing vinyl monomers, vinyl esters, alkenes, conjugated dienes; maleic anhydride, maleic Examples include acids, monoalkyl esters of maleic acid, and dialkyl esters; fumaric acid, monoalkyl esters of fumaric acid, and dialkyl esters; vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, and the like.

  These may be used alone or a plurality of these may be copolymerized. Of these, styrene monomers and (meth) acrylic monomers are preferable from the viewpoint of the ability to stabilize the polymerization by the dispersant, particularly the vinyl polymer B, and more preferable are acrylate monomers and methacrylate monomers. Particularly preferred are acrylate monomers. In the present invention, these preferred monomers may be copolymerized with other monomers and further block copolymerized to form the main chain of the vinyl polymer B.

  The main chain of the vinyl polymer B used in the present invention is preferably obtained by polymerizing mainly these preferable monomers. Specifically, it is preferable that these preferable monomers are contained in the vinyl polymer B itself or the main chain of the vinyl polymer B in a weight ratio of 60% or more. In addition, when the monomer containing the polar functional group X described later or the monomer containing the functional group Y is a styrene monomer or a (meth) acrylic acid monomer, a monomer containing the polar functional group X, and The preferable monomer including the monomer containing the functional group Y may be contained by 60% or more by weight.

  Examples of the (meth) acrylic acid monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-n-propyl, isopropyl (meth) acrylate, (meth ) Acrylic acid-n-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid-t-butyl, (meth) acrylic acid-n-pentyl, (meth) acrylic acid-n-hexyl, (meth) acrylic acid Cyclohexyl, (meth) acrylic acid-n-heptyl, (meth) acrylic acid-n-octyl, (meth) acrylic acid-2-ethylhexyl, (meth) acrylic acid nonyl, (meth) acrylic acid decyl, (meth) acrylic Dodecyl acid, phenyl (meth) acrylate, toluyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylic acid 2-methoxyethyl, (meth) acrylic acid-3-methoxybutyl, (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid stearyl, (meth) acrylic acid Glycidyl, 2-aminoethyl (meth) acrylate, γ- (methacryloyloxypropyl) trimethoxysilane, ethylene oxide adduct of (meth) acrylic acid, trifluoromethylmethyl (meth) acrylate, (meth) acrylic acid 2 -Trifluoromethylethyl, 2-perfluoroethylethyl (meth) acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth) acrylate, 2-perfluoroethyl (meth) acrylate, (meth) Perfluoromethyl acrylate, diperfluoro (meth) acrylate Romethylmethyl, 2-perfluoromethyl-2-perfluoroethylmethyl (meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, and (meth) acrylic acid Examples include 2-perfluorohexadecylethyl.

  Examples of the styrenic monomer include styrene, vinyl toluene, α-methyl styrene, chlorostyrene, styrene sulfonic acid and salts thereof.

  Examples of the fluorine-containing vinyl monomer include perfluoroethylene, perfluoropropylene, and vinylidene fluoride.

  Examples of the silicon-containing vinyl monomer include vinyltrimethoxysilane and vinyltriethoxysilane.

  Examples of the maleimide monomer include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide and the like.

  Examples of the nitrile group-containing vinyl monomer include acrylonitrile and methacrylonitrile.

  Examples of the amide group-containing vinyl monomer include acrylamide and methacrylamide.

  Examples of the vinyl esters include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate.

  Examples of the alkenes include ethylene and propylene, and examples of the conjugated diene include butadiene and isoprene.

(Hydrophobic monomer unit)
Furthermore, the vinyl monomer constituting the main chain of the vinyl polymer B preferably has a hydrophobic monomer unit from the following two points.

  That is, when the polymerization solvent is a hydrophilic solvent, it is important for enhancing the adsorption ability (so-called anchor effect) of the vinyl polymer B to the surface of the polymer fine particles in the production process.

  Further, when the polymerization solvent is a hydrophobic solvent, it is necessary to stabilize the particles by forming a solvation layer around the polymer fine particles in the production process.

  Such a hydrophobic monomer means a monomer having a solubility in water at 20 ° C. of 2% by weight or less, preferably 5 to 95% by weight in the vinyl polymer B, More preferably, it is 20 to 90% by weight.

  Examples of the monomer having a solubility in water at 20 ° C. of 2% by weight or less include propyl methacrylate, butyl acrylate, butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, stearyl acrylate, stearyl methacrylate, lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, perfluoroalkyl acrylate, perfluoroalkyl methacrylate, benzyl acrylate, benzyl methacrylate, Examples include styrene, α-methylstyrene, methyl methacrylate, ethyl methacrylate, and propyl acrylate.

(Method for introducing group Z containing a carbon-carbon double bond)
In addition, as a method for introducing a group Z containing a carbon-carbon double bond at the terminal of the vinyl polymer B, JP-A-5-255415, JP-A-2000-44626, and JP-A-2000-191728. A conventionally known method described in a gazette or the like can be used. For example, a method using an alkenyl group-containing disulfide as a chain transfer agent, a method of adding a “compound having both an alkenyl group and various functional groups (including alkenyl groups)” at the end of polymerization, and a terminal halogen group of the polymer containing an alkenyl group And a method of substituting with a compound.

(Introduction method of polar functional group X)
The method for introducing the polar functional group X into the vinyl polymer B is not particularly limited, but when the vinyl polymer B main chain is constructed,
(1) A method of copolymerizing a monomer containing a polar functional group X,
(2) A method of converting a functional group Y to a polar functional group X after copolymerizing a monomer containing the functional group Y to obtain a vinyl polymer,
(3) a method using an initiator containing a polar functional group X, and
(4) A method of converting a functional group Y into a polar functional group X after obtaining a vinyl polymer using an initiator containing the functional group Y,
The following four methods can be preferably used, and these methods may be performed alone or in combination.

  That is, instead of directly introducing the polar functional group X into the polymer as in the methods (2) and (4) above, the protected functional group Y (hereinafter referred to as “protecting group Y”) may be referred to. Is introduced into the polymer by copolymerizing a monomer containing the functional group Y (protecting group Y), or by using an initiator containing the functional group Y. The vinyl polymer B may be produced by deprotecting the functional group Y in the vinyl polymer introduced with the group Y into the polar functional group X. Here, “protecting” refers to making a highly reactive functional group (polar functional group X) into a functional group that is inactive to the subsequent reaction, and that functional group is called a protecting group. Further, “deprotection” refers to removing protection by performing an appropriate reaction after a necessary reaction is completed for a protected functional group.

  Although the usage-amount of the monomer containing such a polar functional group X and / or the monomer containing the functional group Y is not specifically limited, It is 1 among the monomers which comprise the principal chain of the vinyl polymer B. It can be used in a range of ˜100 mol%, more preferably 2 to 90 mol%, further preferably 5 to 80 mol%, and particularly preferably 10 to 70 mol%. However, it is preferable that at least 0.8 or more polar functional groups X and / or functional groups Y are contained per vinyl polymer B molecule.

(Monomer containing polar functional group X)
As the monomer containing the polar functional group X, a vinyl monomer containing the polar functional group X is preferable, and a monomer represented by the general formula 5 is more preferable.

（式中、Ｒ７は、水素または酸素原子を２つまで含んでいてもよく、また芳香環を含んでいてもよい炭素数１〜２０の炭化水素基を表す。またＲ８、Ｒ９は、直接結合、又は酸素原子を２つまで含んでいてもよく、また芳香環を含んでいてもよい炭素数１〜２０の炭化水素基を表し、お互いに同じであってもよく、異なっていてもよい。）
このような極性官能基Ｘを含有するモノマーとして具体的には、（メタ）アクリル酸、（メタ）アクリル酸カルボキシメチル、（メタ）アクリル酸カルボキシエチル、（メタ）アクリル酸カルボキシフェニル、（メタ）アクリル酸ヒドロキシメチル、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリル酸ヒドロキシフェニル、（メタ）アクリル酸グリシジル、（メタ）アクリル酸アミノメチル、（メタ）アクリル酸アミノエチル、（メタ）アクリル酸アミノフェニル、（メタ）アクリルアミド、（メタ）アクリル酸ジメトキシメチルシリルプロピル基、（メタ）アクリル酸アセトアセトキシエチル、（メタ）アクリル酸メルカプトエチル、カルボキシスチレン（ビニル安息香酸）、ヒドロキシスチレン（ビニルフェノール）、グリシジルスチレン、アミノスチレン（ビニルアニリン）、ジメトキシメチルシリルスチレン、メルカプトスチレン、ブテン酸（クロトン酸）、ペンテン酸、ヘキセン酸、アリルアルコール、ブテノール、ペンテノール、ヘキセノール、エポキシブテン（ブタジエンモノオキシド）、エポキシヘキセン、及びエポキシデセンなどが挙げられる。

(In the formula, R7 represents a hydrocarbon group having 1 to 20 carbon atoms which may contain up to two hydrogen or oxygen atoms and may contain an aromatic ring. R8 and R9 are directly bonded. Or a hydrocarbon group having 1 to 20 carbon atoms which may contain up to two oxygen atoms and may contain an aromatic ring, and may be the same or different from each other. )
Specific examples of the monomer containing the polar functional group X include (meth) acrylic acid, carboxymethyl (meth) acrylate, carboxyethyl (meth) acrylate, carboxyphenyl (meth) acrylate, (meth) Hydroxymethyl acrylate, hydroxyethyl (meth) acrylate, hydroxyphenyl (meth) acrylate, glycidyl (meth) acrylate, aminomethyl (meth) acrylate, aminoethyl (meth) acrylate, amino (meth) acrylate Phenyl, (meth) acrylamide, (meth) acrylic acid dimethoxymethylsilylpropyl group, (meth) acrylic acid acetoacetoxyethyl, (meth) acrylic acid mercaptoethyl, carboxystyrene (vinyl benzoic acid), hydroxystyrene (vinyl phenol), Glicisi Styrene, aminostyrene (vinyl aniline), dimethoxymethylsilyl styrene, mercaptostyrene, butenoic acid (crotonic acid), pentenoic acid, hexenoic acid, allyl alcohol, butenol, pentenol, hexenol, epoxybutene (butadiene monooxide), epoxy hexene And epoxydecene.

(Functional group Y corresponding to polar functional group X)
Here, the functional group Y corresponding to the polar functional group X is not particularly limited. For example, “Protecting Group Chemistry (Oxford Chemistry Primers)” (Oxford Univ Pr (Sd)) 03 by Jeremy Robertson (2000/8) ) And Theodora W. Greene, Peter G. M.M. Previously known as “Protective Groups in Organic Synthesis” by Wuts (Wiley-Interscience) 3rd edition (1999/05/15), “Organic Synthesis Handbook” (Maruzen) (1990/03/31), etc. The functional group Y corresponding to the desired polar functional group X may be used.

  When the polar functional group X is a carboxyl group, the functional group Y is preferably a group represented by the following general formula 3.

（一般式３中のＷは、一般式４で表される。）

(W in general formula 3 is represented by general formula 4.)

（一般式４中、ＣＸは炭素原子またはケイ素原子を表す。Ｒ４〜Ｒ６は水素原子または炭素数１〜２０の芳香環を含んでいてもよい炭化水素基を表す。Ｒ４〜Ｒ６は同じであってもよく、異なっていてもよい。またＲ４〜Ｒ６はそれぞれ独立していてもよいし、互いに結合していてもよい。）
官能基Ｙを表す一般式３中のＷとしては、例えば、メチル基、ｔ−ブチル基、イソボルニル基、ノルボルニル基、アダマンチル基、トリフェニルメチル基（トリチル基）、トリメチルシリル基、及びベンジル基（−ＣＨ２Ｃ６Ｈ５）などが挙げられるが、ｔ−ブチル基、イソボルニル基、ノルボルニル基、アダマンチル基、トリフェニルメチル基、及びトリメチルシリル基からなる群から選ばれる１種以上であることが好ましい。

(In General Formula 4, CX represents a carbon atom or a silicon atom. R4 to R6 represent a hydrogen atom or a hydrocarbon group which may contain an aromatic ring having 1 to 20 carbon atoms. R4 to R6 are the same. And R4 to R6 may be independent from each other or may be bonded to each other.)
Examples of W in the general formula 3 representing the functional group Y include, for example, methyl group, t-butyl group, isobornyl group, norbornyl group, adamantyl group, triphenylmethyl group (trityl group), trimethylsilyl group, and benzyl group (- CH2C6H5) and the like, and it is preferably at least one selected from the group consisting of a t-butyl group, an isobornyl group, a norbornyl group, an adamantyl group, a triphenylmethyl group, and a trimethylsilyl group.

  When the polar functional group X is a hydroxyl group, the functional group Y can be -OG. Here, G is a methyl group, triphenylmethyl group (trityl group), t-butyl group, benzyl group, methoxybenzyl group, trialkylsilyl group (for example, trimethylsilyl group), tetrahydropyranyl group, acetyl group, And at least one selected from the group consisting of benzoyl groups and the like.

When the polar functional group X is an amino group, the functional group Y can be —NHG, —NRG, or —NG ₂ (wherein R may contain up to two oxygen atoms, and Represents a C1-C20 hydrocarbon group that may contain an aromatic ring. Here, G is a formyl group (—CHO), an acetyl group (—COCH ₃ ), a trifluoroacetyl group (—COCF ₃ ), a benzoyl group (—COC ₆ H ₅ ), a benzyl group (—CH ₂ C ₆ H). ₅ ), a methoxycarbonyl group (—C (O) —OCH ₃ ), a t-butoxycarbonyl group (—C (O) —OC (CH ₃ ) ₃ ), and a toluenesulfonyl group (tosyl group: —SO ₂ C _6). It is preferably at least one selected from the group consisting of H ₄ -p-CH ₃ ).

(Monomer containing functional group Y)
Although it will not specifically limit as long as it has the above functional groups Y as a monomer containing the functional group Y, The vinyl-type monomer containing the functional group Y is preferable, and the monomer represented by General formula 6 is suitable. Can be used.

（式中、Ｒ１１は、水素または酸素原子を２つまで含んでいてもよく、また芳香環を含んでいてもよい炭素数１〜２０の炭化水素基を表す。また、Ｒ１２、Ｒ１３は、直接結合または酸素原子を２つまで含んでいてもよく、また芳香環を含んでいてもよい炭素数１〜２０の炭化水素基を表し、お互いに同じであってもよく、異なっていてもよい。）
具体的には、例えば極性官能基Ｘがカルボキシル基の場合、（メタ）アクリル酸ｔ−ブチル、（メタ）アクリル酸イソボルニル、（メタ）アクリル酸ノルボルニル、（メタ）アクリル酸アダマンチル、（メタ）アクリル酸トリフェニルメチル、（メタ）アクリル酸トリメチルシリル、（メタ）アクリル酸ベンジルなどを、官能基Ｙを含有するモノマーとして好適に用いることができる。官能基Ｙを含有するモノマーとしてこれらのモノマーを用いた場合、重合後、比較的温和な条件で選択的に脱保護、すなわち官能基Ｙから極性官能基Ｘへの変換をすることが可能である。

(Wherein R 11 represents a hydrocarbon group having 1 to 20 carbon atoms which may contain up to two hydrogen or oxygen atoms and may contain an aromatic ring. R 12 and R 13 are directly It represents a hydrocarbon group having 1 to 20 carbon atoms which may contain up to two bonds or oxygen atoms and may contain an aromatic ring, and may be the same or different from each other. )
Specifically, for example, when the polar functional group X is a carboxyl group, t-butyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, (meth) acrylic Triphenylmethyl acid, trimethylsilyl (meth) acrylate, benzyl (meth) acrylate, and the like can be suitably used as the monomer containing the functional group Y. When these monomers are used as the monomer containing the functional group Y, it is possible to selectively deprotect, that is, convert the functional group Y to the polar functional group X under relatively mild conditions after polymerization. .

(Initiator containing polar functional group X or functional group Y)
The initiator containing the polar functional group X is not particularly limited as long as it contains the polar functional group X. JP 2000-44626 A, JP 2000-191728 A, and International Publication WO 99/65963 pamphlet. The conventionally well-known thing as described in these etc. can be used. In addition, the initiator containing the functional group Y is not particularly limited as long as it contains the functional group Y, and the initiator described therein or the polar functional group X contained therein is protected to provide the functional group Y. Can be used.

(Conversion from functional group Y to polar functional group X)
The conversion from the functional group Y to the polar functional group X may be carried out as it is in the polymerization solution for the vinyl polymer obtained by copolymerizing the monomer containing the functional group Y, or various steps such as purification. It may be carried out after passing through, or may be carried out alone with a vinyl polymer obtained by copolymerizing a monomer containing functional group Y, or in the presence of other compounds such as a solvent and a catalyst. May be. Furthermore, the temperature at that time is not particularly limited, but in order to shorten the time required for the conversion from the functional group Y to the polar functional group X, it is preferably 50 ° C. or higher, and may be 100 ° C. or higher. It can also be set to 150 ° C. or higher, further 200 ° C. or higher, and can be appropriately determined in consideration of the thermal stability of the polar functional group X, the functional group Y, and the vinyl polymer B.

Examples of the solvent include hydrocarbon solvents such as benzene and toluene; ether solvents such as diethyl ether and tetrahydrofuran; halogenated hydrocarbon solvents such as methylene chloride and chloroform; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. ;
Alcohol solvents such as methanol, ethanol, propanol, isopropanol, n-butyl alcohol, t-butyl alcohol; nitrile solvents such as acetonitrile, propionitrile, benzonitrile; ester solvents such as ethyl acetate, butyl acetate; and ethylene And carbonate solvents such as carbonate and propylene carbonate. These can be used alone or in admixture of two or more.

As the catalyst, for example, when the polar functional group X is a carboxyl group (—COOH) and the functional group Y is —C (O) —OC (CH ₃ ) ₃ , an acid catalyst is preferable. Examples of such an acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; acetic acid, propionic acid, oxalic acid, malonic acid, maleic acid, citric acid, benzoic acid, p-toluenesulfonic acid, and benzenesulfonic acid. And H + type ion exchange resins such as sulfonic acid type. The amount of catalyst in this case is not particularly limited, but is preferably 0.0001 to 50 parts by weight, more preferably 0.001 to 20 parts by weight with respect to 100 parts by weight of the vinyl polymer into which the functional group Y has been introduced. 0.01-10 weight part is further more preferable, and 0.1-5 weight part is especially preferable. When the amount of catalyst is small, conversion from the functional group Y to the polar functional group X may be insufficient, and when the amount of catalyst is large, side reactions may occur or it may be difficult to remove excess catalyst. There is.

(emulsifier)
Examples of the emulsifier that can be used in combination with the production of the polymer fine particles described above include an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier.

  Examples of the anionic emulsifier include a carboxylic acid emulsifier, a sulfonic acid emulsifier, a sulfuric acid emulsifier, a succinic acid emulsifier, and a phosphoric acid emulsifier.

  Examples of the cationic emulsifier include amine types such as alkylamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, and imidazolines, and alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridium salts, and benzotonium chloride. A quaternary ammonium salt type such as

  Examples of the nonionic emulsifier include polyoxyalkylene alkyl ethers typified by polyoxyethylene dodecyl ether, polyoxyalkylene alkyl aryl ethers typified by polyoxyethylene nonylphenyl ether, and polyoxyethylene stearates. Examples thereof include polyoxyalkylene higher fatty acid esters and sorbitan monolaurate esters.

(Chain transfer agent)
In the polymerization of the vinyl monomer A, it is generally used in the polymerization, such as t-dodecyl mercaptan, n-dodecyl mercaptan, t-decyl mercaptan, n-decyl mercaptan, and n-octyl mercaptan. Chain transfer agents such as alkyl mercaptans or alkyl ester mercaptans such as 2-ethylhexyl thioglycolate can also be used as appropriate.

(Crosslinking agent)
In order to introduce the crosslinking component into the polymer fine particles, a so-called crosslinking agent having two or more double bonds is used in the polymerization of the vinyl monomer A. The amount of the crosslinking agent that can be used is not particularly limited. However, while the reaction rate of the vinyl monomer is low, the amount of the crosslinking agent relative to the monomer is preferably 3% by weight or less, more preferably 1.5%. It is good to carry out by weight% or less. When the reaction rate of the vinyl monomer is high, if necessary, 20% by weight or less of a crosslinking agent may be added all at once, divided or continuously based on the remaining vinyl monomer. It is more preferable to add in portions or continuously in accordance with the progress of the polymerization, and it may be added in a solvent or mixed with a vinyl monomer if a semi-batch polymerization operation is performed.

  The concentration of the cross-linking agent must be suppressed at the initial stage of the polymerization. If the cross-linking agent is present at a certain concentration or more at the time of initial stabilization of the core particles, the cross-linking structure is formed between the core particles. This is because the stability is extremely hindered. Once the core particles are stabilized, the subsequent particle growth reaction, that is, the process from swelling to polymerization of the core particles by the monomer is not delayed. Done.

  Preferred crosslinking agents include allyl (meth) acrylate, diallyl phthalate, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, diallyl itaconate, divinylbenzene, triary Examples thereof include polyfunctional monomers having two or more polymerizable unsaturated groups in the molecule as represented by lucyanurate and triallyl isocyanurate. These may be used alone or in combination of two or more.

(Polymerization initiator)
In the present invention, a polymerization initiator is used to polymerize the vinyl monomer A. Although it does not specifically limit as said polymerization initiator, The thing which melt | dissolves in the said polymerization solvent by the polymerization initiator normally used in radical polymerization is preferable. For example, benzoyl peroxide, lauroyl peroxide, stearoyl peroxide, octanoyl peroxide, orthochloroperoxybenzoyl, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethyl Organic peroxides such as hexanoate, di-t-butyl peroxide, t-butyl peroxypivalate; 2,2'-azobisisobutyronitrile, azobiscyclohexacarbonitrile, 2,2'- Azo-based compounds such as azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) or 2,2'-azobis (2-methylbutyronitrile) One or a combination of two or more selected from persulfide compounds such as potassium persulfate It can be suitably used.

  The amount of the polymerization initiator used is not particularly limited, and may be appropriately determined in consideration of the molecular weight of the polymer fine particles to be produced, the decomposition temperature of the polymerization initiator to be used, etc. The mixing ratio with the polymerization initiator is 100: 0.01 to 100: 100 by weight in order to make the polymerization yield sufficient and to carry out stable polymerization while maintaining the polymerization rate at an appropriate speed. 40 is preferable.

(Water-soluble polymer compound)
Examples of the water-soluble polymer compound include natural water-soluble polymers such as starch and gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylate, polymethacrylate, polyvinyl ether, polyethylene oxide, methylcellulose, hydroxymethylcellulose, hydroxy Examples thereof include propylmethylcellulose, carboxymethylcellulose, sulfonated polystyrene glycol, styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinyl acetate-maleic acid copolymer, and the like. These water-soluble polymer compounds may be used alone or in combination of two or more.

(Poorly water-soluble substance)
As the poorly water-soluble substance, a substance having a solubility in water at 20 ° C. of 0.05% by weight or less and a molecular weight of 20,000 or less can be preferably used. Examples of such poorly water-soluble substances include (meth) acrylic acid alkyl ester monomers having a long-chain alkyl group having 12 to 30 carbon atoms, such as stearyl methacrylate and dinonylphenyl methacrylate. , Higher alcohols having 12 to 22 carbon atoms typified by cetyl alcohol or stearyl alcohol, hydrocarbons typified by hexadecane, octadecane, etc., halogens typified by 1-chlorododecane, 1-chlorodecane, etc. 1 type, or 2 or more types of combinations chosen from activated hydrocarbons etc. can be used.

  However, when the polymer particles obtained by the production method of the present invention are used as a resin modifier, non-polymerizable compounds such as higher alcohols, hydrocarbons and halogenated hydrocarbons are used as poorly water-soluble substances. If used, the poorly water-soluble substance remaining in the polymer particles may cause problems such as gas generation during molding and excessive lubricity. In order to solve this problem, it is preferable to use a polymerizable poorly water-soluble substance having at least one polymerizable unsaturated group in the molecule. In addition, metals such as cobalt, iron and aluminum and alloys thereof; fine powders of metal oxides composed of iron oxide, copper oxide, nickel oxide, etc .; additives such as pigments and dyes such as carbon black nigrosine dye and aniline blue It is also possible to use.

  Next, the present invention will be described by way of specific examples, but these are all illustrative and do not limit the contents of the present invention. In the following examples and comparative examples, the number average molecular weight and the molecular weight distribution (ratio of weight average molecular weight to number average molecular weight) were calculated by a standard polystyrene conversion method using gel permeation chromatography (GPC). However, a GPC column filled with polystyrene cross-linked gel (shodex GPC K-804; manufactured by Showa Denko KK) was used as the GPC solvent with chloroform. The number of functional groups introduced per polymer molecule was calculated based on concentration analysis by 1H-NMR and a number average molecular weight determined by GPC. NMR was measured at 23 ° C. using ASX-400 manufactured by Bruker and using deuterated chloroform as a solvent.

  In addition, the number average particle diameter, volume average particle diameter, and CV value of the polymer fine particles were measured with a scanning electron microscope (JSM-6300F, JSM-6300F), and 200 randomly selected. The fine particles were image-analyzed and calculated according to the above-mentioned formula 1, formula 2, and formula 3.

Production Example 1 Production of Vinyl Polymer B (B1) 20 parts by weight of t-butyl acrylate and 80 parts by weight of n-butyl acrylate were mixed well to obtain 100 parts by weight of a monomer mixture. 40 parts by weight of this monomer mixture, 0.42 parts by weight of copper (I) bromide, and 8.8 parts by weight of acetonitrile were charged and stirred at 80 ° C. under a nitrogen stream. To this was added 1.9 parts by weight of ethyl 2-bromoentrate, and the mixture was further stirred at 80 ° C. To this, 0.034 parts by weight of pentamethyldiethylenetriamine (hereinafter referred to as triamine) was added to initiate the reaction. On the way, the remaining 60 parts by weight of the monomer mixture was intermittently added, and further stirring was continued while adding triamine as appropriate so that the temperature of the reaction solution became 80 ° C to 90 ° C. After the monomer reaction rate reached 95%, the inside of the reaction vessel was depressurized to remove volatile components.

  This was diluted with toluene, synthetic hydrotalcite, aluminum silicate and filter aid were added, and the mixture was heated and stirred in an oxygen / nitrogen mixed gas atmosphere. After removing solids, the solution was concentrated. This was diluted with N, N-dimethylacetamide and stirred with heating at 70 ° C. for 7 hours in the presence of potassium methacrylate. After concentration, the solid was removed by diluting with toluene. To this, 100 parts by weight of toluene and 4 parts by weight of p-toluenesulfonic acid were added and stirred at 100 ° C. for 6 hours. After filtering this, volatile content was removed to obtain heavy vinyl-based coalescence B1 as an example of vinyl-based polymer B.

  The number average molecular weight of this vinyl polymer B1 is 8400, the molecular weight distribution is 1.2, the average number of methacryloyl groups introduced per molecule of the polymer is 1.0, and among the structural units derived from the monomers constituting the main chain The structural unit containing a carboxyl group was 20 mol%.

  That is, the vinyl polymer B1 has a polar functional group (carboxyl group) in the main chain of 20 mol% and a group having a carbon-carbon double bond (methacryloyl group) at the molecular end.

(Production Example 2) Production of Vinyl Polymer B (B2) As Production Example 2, vinyl polymer B2 used in Example 3 below was produced. Specifically, in the production example 1, a vinyl polymer B2 which is a dispersant and an example of the vinyl polymer B is similarly used except that potassium acrylate is used instead of potassium methacrylate. Manufactured.

  The number average molecular weight of this vinyl polymer B2 is 7600, the molecular weight distribution is 1.2, the average number of acryloyl groups introduced per molecule of the polymer is 1.0, and among the structural units derived from the monomers constituting the main chain The structural unit containing a carboxyl group was 20 mol%.

  That is, the vinyl polymer B2 has a polar functional group (carboxyl group) in the main chain at 20 mol% and a group having a carbon-carbon double bond (acryloyl group) at the molecular end.

(Example 1) Production of polymer fine particles P1 In a 500 ml glass reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen introduction tube, 750 parts by weight of methanol, 250 parts by weight of water, 100 parts by weight of methyl methacrylate 3 parts by weight of allyl methacrylate, 2 parts by weight of vinyl polymer B1 as a dispersant, and 28% by weight aqueous ammonia solution (0.6 parts by weight of pure ammonia) were charged. Using a meniscus stirring blade having a blade diameter of 6 cm, stirring was performed at a stirring speed of 170 rpm. The temperature inside the reactor was adjusted to 60 ° C. while bubbling nitrogen gas. It was confirmed that the vinyl polymer B1 was completely dissolved and the mixed solution in the reactor was completely transparent. After confirming that the reactor internal temperature was stable at 60 ° C., the nitrogen gas piping was pulled up from the reaction solution and fixed so that its tip was above the liquid level. Next, 2 parts by weight of 2,2′-azobisisobutyronitrile was charged to initiate polymerization. It was confirmed that turbidity was generated in the reaction solution within a few minutes after 2,2'-azobisisobutyronitrile was added, and particles that did not dissolve in the medium were generated. Five hours after the addition of 2,2′-azobisisobutyronitrile, the reaction solution was cooled to 40 ° C. to obtain a dispersion of polymer fine particles P1.

  Immediately, the entire amount of the dispersion was filtered through a 150-mesh metal mesh, and the presence or absence of aggregation was confirmed. Almost no aggregate was observed. Moreover, almost no agglomerates adhered to the inner wall of the reactor, the stirring blade, and the thermometer.

  With respect to the dispersion after filtration, the polymerization conversion was determined from the solid content value obtained by drying at 120 ° C. for 60 minutes and the theoretical solid content value calculated from the preparation, and found to be 94.8%. Further, the dispersion was allowed to stand separately until the supernatant became transparent, and the sedimented portion was collected and dried at room temperature to obtain polymer fine particles P1. The obtained polymer fine particles P1 were observed with a scanning electron microscope (hereinafter referred to as SEM). As a result, dv = 1.33 μm, dn = 1.33 μm, and CV = 5.8%.

(Example 2) Production of polymer fine particles P2 As Example 2, the same procedure was carried out except that 1 part by weight of vinyl polymer B1 was used instead of 2 parts by weight of vinyl polymer B1 in Example 1 above. Thus, a dispersion of polymer fine particles P2 was obtained.

  In the same manner as in Example 1, when the total amount of the dispersion was filtered through a 150-mesh metal net and the presence or absence of aggregation was confirmed, almost no aggregate was observed. Moreover, almost no agglomerates adhered to the inner wall of the reactor, the stirring blade, and the thermometer.

  About the dispersion liquid after filtration, when the polymerization conversion rate was calculated | required from the solid content value calculated | required by 120 degreeC x 60 minute drying and the theoretical solid content value calculated from preparation, it was 95.0%. Furthermore, the dispersion was allowed to stand separately until the supernatant became transparent, and the sedimented portion was collected and dried at room temperature to obtain polymer fine particles P2. The obtained polymer fine particles P2 were observed with a scanning electron microscope (hereinafter referred to as SEM). As a result, dv = 1.42 μm, dn = 1.41 μm, and CV = 4.2%. In comparison, the CV value, which is an index of monodispersibility, was a good result even though the amount of vinyl polymer B1 used was 1 part by weight, which was half.

(Example 3) Production of polymer fine particles P3 As Example 3, the same procedure was carried out except that, instead of 2 parts by weight of the vinyl polymer B1 in Example 1, the vinyl polymer B2 was changed to 10 parts by weight. Thus, a dispersion of polymer fine particles P3 was obtained.

  In the same manner as in Example 1, when the total amount of the dispersion was filtered through a 150-mesh metal net and the presence or absence of aggregation was confirmed, almost no aggregate was observed. Moreover, almost no agglomerates adhered to the inner wall of the reactor, the stirring blade, and the thermometer.

  With respect to the dispersion liquid after filtration, the polymerization conversion was determined from the solid content value obtained by drying at 120 ° C. for 60 minutes and the theoretical solid content value calculated from the preparation, and found to be 94.9%. Furthermore, the dispersion was allowed to stand separately until the supernatant became transparent, and the sedimented portion was collected and dried at room temperature to obtain polymer fine particles P3. The obtained polymer fine particles P3 were observed with a scanning electron microscope (hereinafter referred to as SEM). As a result, dv = 1.62 μm, dn = 1.61 μm, and CV = 6.5%.

(Comparative Example 1)
A dispersion of polymer fine particles is produced in the same manner as in Example 1 except that 10 parts by weight of polyvinylpyrrolidone (BASF, K-90) is used in place of the vinyl polymer B1. I tried to do that. As a result, a large amount of agglomerates was generated during the polymerization, and the polymerization was stopped during the polymerization. Therefore, polymer fine particles could not be obtained.

Claims (12)

In a polymerization solution obtained by dissolving 100 parts by weight or less of a vinyl monomer A and 0.01% by weight or more of a vinyl polymer B with respect to the vinyl monomer A in 100 parts by weight of a polymerization solvent. A method for producing polymer fine particles by polymerizing the vinyl monomer A to produce polymer fine particles insoluble in the polymerization solvent,
The polymerization solvent is a hydrophilic solvent;
The vinyl polymer B has a number average molecular weight of 3000 or more, and the ratio of the weight average molecular weight (Mw) and the number average molecular weight (Mn) (Mw / Mn) measured by gel permeation chromatography. Is less than 1.8 and has at least one polar functional group X selected from the group consisting of a carboxyl group, a hydroxyl group, an epoxy group, an amino group, an amide group, a silyl group, an acetylacetonato group, and a mercapto group. The proportion of the structural unit having the polar functional group X among the structural units derived from the monomers constituting the main chain of the vinyl polymer B is 1 to 100 mol%, and the polar functional group X is the vinyl polymer B. A carbon-carbon double group represented by general formula 2 and / or a group Z containing at least 0.8 or more per molecule and containing a carbon-carbon double bond represented by general formula 1 below: Result A method for producing polymer fine particles, comprising a group Z containing a group at one or more molecular ends.

(In the formula, R1 and R2 represent hydrogen or a hydrocarbon group optionally containing an aromatic ring having 1 to 20 carbon atoms. R3 represents a direct bond or an aromatic group having 1 to 20 carbon atoms. Represents a hydrocarbon group which may contain a ring.)   The method for producing polymer fine particles according to claim 1, wherein the main chain of the vinyl polymer B is a main chain produced by radical polymerization.   The method for producing polymer fine particles according to claim 2, wherein the radical polymerization is living radical polymerization. The method for producing polymer fine particles according to claim 3, wherein the living radical polymerization is atom transfer radical polymerization.   The main chain of the vinyl polymer B is at least one selected from the group consisting of (meth) acrylic monomers, acrylonitrile monomers, aromatic vinyl monomers, fluorine-containing vinyl monomers, and silicon-containing vinyl monomers. The method for producing polymer fine particles according to any one of claims 1 to 4, which is a main chain obtained by polymerizing monomers in a weight ratio of 60% or more.   The method for producing polymer fine particles according to any one of claims 1 to 5, wherein R1 in the group Z containing the carbon-carbon double bond is hydrogen and / or a methyl group.   The method for producing polymer fine particles according to claim 1, wherein R 2 in the group Z containing the carbon-carbon double bond is hydrogen and / or a methyl group. The method for producing polymer fine particles according to any one of claims 1 to 7 , wherein the vinyl polymer B contains a hydrophobic monomer unit as a constituent monomer unit. The polar functional group X is a carboxyl group, and the vinyl monomer A during polymerization, at least a part of the carboxyl group, according to claim 1 which is neutralized by alkali A method for producing polymer fine particles. Polymer fine particles produced by the method for producing polymer fine particles according to any one of claims 1 to 9 . The polymer fine particles according to claim 10 , which have a volume average particle diameter of 0.05 to 20 µm and a CV value of 30% or less. The polymer fine particles according to claim 11 , wherein the volume average particle diameter is 1 to 20 μm.