JP2022134730A - Hydroxy group-containing polymer and method for producing hydroxy group-containing polymer - Google Patents

Abstract

To provide a hydroxy group-containing polymer that has hydrophilicity and adhesion to metal and the like.SOLUTION: Provided is a hydroxy group-containing polymer having an average particle size of 1 to 1000 nm and having a group represented by the following formula (I). *-O-Z --- (I). (In formula (I), Z is a monovalent group in which two or more of hydrogen atoms of a monovalent hydrocarbon group having 3 to 8 carbon atoms are substituted with hydroxy group, * represents the bonding position of the monovalent group.)SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to resin particles having excellent hydrophilicity and a method for producing the same.

Microparticles containing hydrophilic polymers are used in various fields. Fine particles are required from the viewpoint of transparency and the like, and a crosslinked polymer having a carboxyl group is known as a finely divided resin of submicron order (Patent Document 1).

Patent No. 6150031

However, as a result of extensive studies by the present inventors, although the crosslinked polymer having a carboxyl group has sufficient hydrophilicity, it has insufficient adhesion to metals, etc., and is not suitable for various uses such as medical, cosmetic, and industrial applications. It was found that there is still room for improvement in terms of use.

In the present specification, the range “α to β” means “α or more and β or less”. As used herein, "acid (salt)" means "acid and/or its salt". "(Meth)acrylic" means "acrylic and/or methacrylic".

The hydroxyl group-containing polymer of the present invention has an average particle size of 1 to 1000 nm and has a group represented by the following formula (I).
*-Y-Z (I)
(In formula (I), Z is a monovalent group in which two or more hydrogen atoms of a monovalent hydrocarbon group having 3 to 8 carbon atoms are substituted with hydroxyl groups, and Y is an oxygen atom or —NH -, and * represents the bonding position of the monovalent group.)

The polymer contains a structural unit (A) derived from a monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group, and a structural unit ( A) is preferably contained in an amount of 50% by mass or more.

The polymer preferably contains a structural unit derived from a crosslinkable monomer.

Preferably, the structural unit (A) of the polymer is derived from glycerol (meth)acrylate or dihydroxypropyl (meth)acrylamide.

The hydroxyl group-containing polymer comprises a polymerization step of precipitation polymerization of a monomer component containing a monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group and a crosslinkable monomer. I like it.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a submicron-order hydroxyl group-containing polymer having hydrophilicity and excellent adhesion to a substrate, and a method for producing the hydroxyl group-containing polymer.

(Hydroxyl group-containing polymer)
The hydroxyl group-containing polymer of the present embodiment has an average particle diameter of 1 to 1000 nm, preferably 10 to 900 nm, more preferably 50 to 800 nm, more preferably 100 to 700 nm, in order to form a uniform coating film. is particularly preferred. The average particle size of the hydroxyl group-containing polymer is the volume average particle size of polymer particles, that is, the polymer particle size, and can be specifically measured by the dynamic light scattering method described in Examples. In the present specification, polymerized particles mean particles that are present in the reaction medium after reaction when produced by various polymerization methods, and are different from dry powder particles obtained by drying after reaction. Dry powder particles are greatly affected by swelling and secondary agglomeration due to the dispersion solvent. The particle size is 0.1 μm to 10 μm, preferably 0.2 μm to 5 μm. It can be measured by the dynamic light scattering method described in Examples in the same manner as the polymer particle size.

The coefficient of variation of the particle size of the hydroxyl group-containing polymer (CV value, standard deviation of particle size divided by number average particle size) is preferably 1 to 20%, more preferably 1 to 10%.

Since the hydroxyl group-containing polymer of the present embodiment has hydrophilicity and adhesion to a substrate, it can be used as an additive for imparting antifogging properties and/or hydrophilicity, an additive for preventing condensation, and an antifouling material in industrial applications. , thickeners, chelating agents (ion adsorbents), paints, various additives and binders for electrical and electronic materials, thickeners used in cosmetics, water retention agents, drug carriers, drug delivery systems in the medical field It can also be used as a carrier, nanogel material, and the like.

The hydroxyl-containing polymer of this embodiment contains a hydroxyl-containing polymer.

The hydroxyl group-containing polymer of this embodiment has a group represented by the above formula (I).
In formula (I), Z preferably has 3 to 6 carbon atoms, more preferably 3 to 5 carbon atoms. Moreover, the number of hydroxyl groups that Z has is preferably 2 or 3, more preferably 2.

The hydroxyl group-containing polymer is not particularly limited as long as it is a polymer having a group represented by formula (I) above. The hydroxyl-containing polymer may be a polyester compound, a polyether compound, a polyamide compound, a polyimide compound, a polyamideimide compound, a polyamic acid compound, a polyvinyl compound, and combinations thereof. Moreover, the hydroxyl group-containing polymer may be a homopolymer or a copolymer. The group represented by formula (I) may be bonded to the terminal of the hydroxyl group-containing polymer (I), or may be bonded to a portion other than the terminal. When the hydroxyl group-containing polymer (I) has a main chain and a graft chain, the group represented by formula (I) may be bonded to the main chain or to the graft chain. In addition, a polymer obtained by introducing a group represented by the formula (I) into a natural polymer such as gelatin, hyaluronic acid or alginic acid can also be used as the hydroxyl group-containing polymer.

The hydroxyl group-containing polymer preferably contains 0.0001 mol/g or more of the group represented by formula (I), more preferably 0.001 mol/g or more, even more preferably 0.0025 mol/g or more, and 0.001 mol/g or more. 005 mol/g or more is even more preferable. The unit mol/g is the number of moles of the group represented by the formula (I) per 1 g of the hydroxyl group-containing polymer.

The hydroxyl-containing polymer preferably contains a structural unit derived from a monomer having a group represented by formula (I) and an ethylenically unsaturated group (hereinafter also referred to as monomer (I)). It should be noted that the "structural unit derived from the monomer (I)" is not only a structural unit obtained by polymerizing the monomer (I), but also a method other than polymerizing the monomer (I). Even if the obtained structural unit has the same structure as the structural unit obtained by polymerizing the monomer (I), it is a "structural unit derived from the monomer (I)". included. For example, the hydroxyl group in the Z group of the monomer (I) is protected by a protecting group, and the structural unit obtained when the monomer (I) is polymerized and then deprotected is the monomer (I). Since the same structural unit as in the case of polymerization is obtained, it is included in the "structural unit derived from the monomer (I)". Further, when the Z group of the monomer (I) has a plurality of hydroxyl groups, after polymerizing a monomer in which two of the hydroxyl groups form a cyclic ether structure by intramolecular dehydration, Since the structural unit obtained by hydrolyzing the cyclic ether structure back to a hydroxyl group with an acid or the like has the same structure as in the case of polymerizing the monomer (I), the "structural unit derived from the monomer (I) "include.

Monomer (I) is preferably a compound represented by formula (IA) below.

（ＩＡ）

(IA)

(In formula (IA), Z and Y have the same meanings as Z and Y in formula (I), respectively, and R represents a hydrogen atom or a methyl group.)
Z is preferably a group represented by formula (II) below.

（ＩＩ）

(II)

(In formula (II), R ¹ is —CH(OH)CH ₂ OH or —CH ₂ OH, R ² is a hydrogen atom or —CH ₂ OH, R ³ is a hydrogen atom or —CH ₂ OH, and * represents the bonding position of the group represented by formula (II).)
Monomer (I) is preferably glycerol mono(meth)acrylate, 2,3-dihydroxypropyl(meth)acrylamide or 1,3-dihydroxypropyl(meth)acrylamide, more preferably glycerol mono(meth)acrylate.

The structural unit derived from the monomer (I) may be a monomer that can be hydrolyzed after (co)polymerization to generate a hydroxyl group, such as the following monomer (IB). Also included are the structural units from which they are derived.

（ＩＢ）

(IB)

(In formula (IB), R ¹¹ represents a hydrogen atom or a methyl group, and R ¹³ and R ¹⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms)
When the monomer (IB) is polymerized and then acid-treated, the dioxolane ring is hydrolyzed to generate two hydroxyl groups in the structural unit.

The hydroxyl group-containing polymer may be a copolymer of monomer (I) and other monomers including crosslinkable monomers.

(Crosslinkable monomer)
Examples of crosslinkable monomers include polyfunctional polymerizable monomers having two or more polymerizable unsaturated groups, and monomers having self-crosslinkable functional groups such as hydrolyzable silyl groups. mentioned.
The polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as (meth)acryloyl groups and alkenyl groups in the molecule, and includes polyfunctional (meth)acrylate compounds, polyfunctional alkenyl compounds, ( Examples include compounds having both a meth)acryloyl group and an alkenyl group. These compounds may be used individually by 1 type, and may be used in combination of 2 or more type. Among these, a polyfunctional alkenyl compound is preferable because it is easy to obtain a uniform crosslinked structure, and a polyfunctional allyl ether compound having a plurality of allyl ether groups in the molecule is particularly preferable.

Examples of polyfunctional (meth)acrylate compounds include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di( Di(meth)acrylates of dihydric alcohols such as meth)acrylates; Poly(meth)acrylates such as tri(meth)acrylates and tetra(meth)acrylates of trihydric or higher polyhydric alcohols such as meth)acrylates and pentaerythritol tetra(meth)acrylates; Bisamides and the like can be mentioned.

Polyfunctional alkenyl compounds include polyfunctional allyl ether compounds such as trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, tetraallyloxyethane, and polyallyl saccharose; and polyfunctional vinyl compounds such as divinylbenzene.
Compounds having both a (meth)acryloyl group and an alkenyl group include allyl (meth)acrylate, isopropenyl (meth)acrylate, butenyl (meth)acrylate, pentenyl (meth)acrylate, and (meth)acrylic acid. 2-(2-vinyloxyethoxy)ethyl and the like can be mentioned.

Specific examples of the monomer having a self-crosslinkable crosslinkable functional group include hydrolyzable silyl group-containing vinyl monomers, N-methylol(meth)acrylamide, N-methoxyalkyl(meth)acrylate, and the like. is mentioned. These compounds can be used individually by 1 type or in combination of 2 or more types.

The hydrolyzable silyl group-containing vinyl monomer is not particularly limited as long as it is a vinyl monomer having at least one hydrolyzable silyl group. For example, vinylsilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinyldimethylmethoxysilane; silyls such as trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, and methyldimethoxysilylpropyl acrylate; Group-containing acrylic acid esters; silyl group-containing methacrylic acid esters such as trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, methyldimethoxysilylpropyl methacrylate, and dimethylmethoxysilylpropyl methacrylate; trimethoxysilylpropyl vinyl ether, etc. and silyl group-containing vinyl esters such as vinyl trimethoxysilylundecanoate.

Di(meth)acrylates of dihydric alcohols, tri(meth)acrylates and tetra(meth)acrylates of trihydric or higher polyhydric alcohols are preferred in order to obtain particles that are easy to handle and flexible as powders. .

When the hydroxyl group-containing polymer of the present invention is crosslinked with a crosslinkable monomer, the amount of the crosslinkable monomer used is a monomer other than the crosslinkable monomer (non-crosslinkable monomer ) is preferably 0.01 to 40 mol %, more preferably 0.1 to 10 mol %, relative to the total amount of ). When the amount of the crosslinkable monomer used is 0.01 mol % or more, it is preferable in that the binding property and the stability of the mixture layer slurry are improved. If it is 40 mol % or less, the stability of the hydroxyl group-containing polymer tends to be high. In addition, the amount of the crosslinkable monomer used is preferably 0 to 50% by mass, more preferably 0.1 to 25% by mass, more preferably 0.1 to 25% by mass, based on all constituent monomers of the hydroxyl group-containing polymer. is 0.5 to 20% by mass, more preferably 1 to 105% by mass. In the present specification, the term "total constituent monomers" specifically means the total amount of monomers including monomer (I) used in the polymerization.

(Other monomers other than crosslinkable monomers)
Other monomers include compounds having a cross-linking monomer ethylenically unsaturated group and an alkylene glycol group or polyalkylene glycol group.

Other monomers include (meth)acrylamide, N-alkyl(meth)acrylamides (eg, N,N-dimethyl(meth)acrylamide), N-vinylpyrrolidone, N-vinylpyrrolidinone, N-vinylacetamide. , N-vinylformamide, hydroxyethyl (meth)acrylate, neutral hydrophilic monomers such as hydroxypropyl (meth)acrylate, (meth)acrylic acid or salts thereof, maleic acid or salts thereof, fumaric acid or salts thereof, Anionic hydrophilic monomers such as itaconic acid or its salts, (meth)acrylamidomethylpropanesulfonic acid or its salts, vinylphosphonic acid or its salts, vinylbenzoic acid or its salts, 3-aminopropyl (meth)acrylamide ( APMA), (meth)acrylamidopropyltrimethylammonium chloride (MAPTAC), N,N-dimethylaminoethyl (meth)acrylate, and other cationic hydrophilic monomers may also be mentioned.

Other monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, methoxyethyl (meth) acrylate, hydrophobic monomers such as styrene, glycidyl (meth) acrylate, isopropenyl Reactive group-containing monomers such as oxazoline, vinyloxazoline, and maleic anhydride can also be used.

Other monomers may be used alone or in combination of two or more.

The content of structural units derived from a monomer having a carboxyl group and an ethylenically unsaturated group in the hydroxyl group-containing polymer is less than 50% by mass relative to the total amount of the hydroxyl group-containing polymer (I). It may be 25% by mass or less, and may be 5% by mass or less. The structural unit derived from a monomer having a carboxyl group and an ethylenically unsaturated group may be a structural unit obtained by polymerizing the monomer, provided that it has the same chemical structure. , a structural unit obtained by a method other than polymerizing the monomer (for example, a structural unit obtained by polymerizing a corresponding ester compound and then hydrolyzing the ester group to form a carboxyl group, etc.).

Compounds having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group include compounds represented by the following formula (III).

（ＩＩＩ）

(III)

In the above formula (III), A represents a hydrogen atom or an organic group having 1 to 20 carbon atoms, X represents -C(=O)-, -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ — or represents a single bond, Q represents an alkylene group having 2 to 20 carbon atoms, n represents a repeating unit of an alkylene oxide group and represents a number of 1 to 200, and A _k represents a hydrogen atom or a substituent. It represents an organic group having 1 to 20 carbon atoms which may be present.

Each of A and A _k is preferably a hydrogen atom or an organic group having 1 to 12 carbon atoms, more preferably a hydrogen atom or an organic group having 1 to 8 carbon atoms, and a hydrogen atom or an organic group having 1 to 8 carbon atoms. 1 to 4 organic groups are preferred. When the organic group has a substituent, the number of carbon atoms including the substituent is more preferably within the above range. More preferably, A and _Ak above are each a hydrogen atom or a methyl group.

The above Q is preferably an alkylene group having 2 to 5 carbon atoms, more preferably an ethylene group, an n-propylene group or an isopropylene group. In addition, Q may contain only one type of alkylene group, but may contain two or more types of alkylene groups. When Q contains an ethylene group, preferably 50 to 100 mol% of all alkylene glycol units in the polyalkylene glycol group is an ethylene group, more preferably 80 to 100 mol% is an ethylene group, 90 It is preferred that ~100 mol % be ethylene groups.

m may be the average number of added moles for all compounds represented by formula (III). m is preferably 1-100, more preferably 5-80, even more preferably 10-60.

When X is represented by -C (= O) -, (meth) alkylene oxide adducts having 1 to 100 carbon atoms to acrylic acid: carbon atoms such as methanol, ethanol, 2-propanol, 1-butanol alkoxypolyalkylene glycols obtained by adding alkylene oxides having 1 to 100 carbon atoms to alkyl alcohols having 1 to 30 carbon atoms, and esters of (meth)acrylic acid; and the like.

When X is -CH ₂ -, -CH _{2 CH 2 -, -CH 2 CH 2 CH 2 - , allyl alcohol} , methallyl alcohol, 2-buten-1-ol, 2-methyl-2- Buten-1-ol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, vinyl alcohol and other unsaturated alcohols Compounds having a structure in which 1 to 100 moles of alkylene oxide are added can be mentioned, and one or more of these can be used.

Further, the compound represented by formula (III) includes polyalkylene oxide chain-containing (meth)acrylic acid esters such as 2-ethylhexylcarbitol (meth)acrylate, methoxybutyl (meth)acrylate, and methoxyethyl (meth)acrylate. and alkoxyalkyl (meth)acrylic acid esters such as ethoxybutyl (meth)acrylate.

The content of the structural unit derived from the monomer (I) in the hydroxyl group-containing polymer may be 25 to 99.9% by mass, when the crosslinkable monomer is included, and may be 40 to 99.5% by mass. It's okay. It may be from 25 to 100% by weight if no cross-linkable monomer is included, and may be from 50 to 99.9% by weight. When the hydroxyl group-containing polymer contains an ethylenically unsaturated group and a structural unit derived from a compound having an alkylene glycol group or a polyalkylene glycol group, the content of the structural unit is added to the total amount of the hydroxyl group-containing polymer (I). may be 0.01 to 25% by mass.

(Method for producing hydroxyl group-containing polymer)
For the hydroxyl group-containing polymer of the present invention, known polymerization methods such as solution polymerization, precipitation polymerization and dispersion polymerization, suspension polymerization, and inverse emulsion polymerization can be used. , dispersion polymerization and suspension polymerization (reverse suspension polymerization) are preferred. A precipitation polymerization method or a dispersion polymerization method is more preferred, and a precipitation polymerization method is particularly preferred, in terms of obtaining better performance in terms of binding properties and the like.

Precipitation polymerization is a method of producing a polymer by carrying out a polymerization reaction in a solvent that dissolves the unsaturated monomer as the starting material but does not substantially dissolve the resulting polymer. As the polymerization progresses, the polymer particles become larger due to aggregation and growth, and a dispersion liquid of polymer particles is obtained in which primary particles of several tens nm to several hundred nm are secondary aggregated to several μm to several tens μm.

The secondary aggregation can be suppressed by selecting a dispersion stabilizer, a polymerization solvent, and the like. In general, precipitation polymerization in which secondary aggregation is suppressed is called dispersion polymerization.

In the case of precipitation polymerization, a solvent selected from water and various organic solvents can be used as the polymerization solvent in consideration of the type of monomers to be used. In order to obtain a polymer having a longer primary chain length, it is preferable to use a solvent with a small chain transfer constant.

Specific polymerization solvents include water-soluble solvents such as methanol, t-butyl alcohol, acetone, acetonitrile and tetrahydrofuran, as well as benzene, ethyl acetate, dichloroethane, n-hexane, cyclohexane, benzonitrile and n-heptane. These can be used alone or in combination of two or more. Alternatively, a mixed solvent of these and water may be used. A water-soluble solvent in the present invention refers to a solvent having a solubility in water at 20° C. of greater than 10 g/100 ml.

Among the above, the formation of coarse particles and adhesion to the reactor are small, and the polymerization stability is good. Acetonitrile is preferable in that it is easy to use), that a polymer with a small chain transfer constant and a large degree of polymerization (primary chain length) can be obtained, and that the operation is easy during the neutralization process described later.

In addition, it is preferable to add a small amount of a highly polar solvent to the polymerization solvent in order to allow the neutralization reaction to proceed stably and rapidly in the process neutralization. Such highly polar solvents preferably include water and methanol. The amount of the highly polar solvent used is preferably 0.05 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, still more preferably 0.1 to 1% by mass, based on the total mass of the medium. .0% by mass. When the proportion of the highly polar solvent is 0.05% by mass or more, the effect on the neutralization reaction is observed, and when it is 10.0% by mass or less, no adverse effect on the polymerization reaction is observed.

In the case of dispersion polymerization, as in precipitation polymerization, a solvent selected from water and various organic solvents can be used as the polymerization solvent in consideration of the type of monomers to be used, but secondary aggregation is suppressed. A dispersion stabilizer can be used to

As specific dispersion stabilizers, polymeric dispersants, nonionic emulsifiers, and the like can be used.
Polymer-type dispersants include polyhydroxystyrene, polystyrene sulfonic acid, vinylphenol-(meth)acrylate copolymer, styrene-(meth)acrylate copolymer, styrene-vinylphenol-(meth)acryl Polystyrene derivatives such as acid ester copolymers; Poly(meth)acrylic acid derivatives such as poly(meth)acrylic acid, poly(meth)acrylamide, polyacrylonitrile, polyethyl(meth)acrylate, and polybutyl(meth)acrylate; polymethyl vinyl ether , polyvinyl alkyl ether derivatives such as polyethyl vinyl ether, polybutyl vinyl ether, and polyisobutyl vinyl ether; cellulose derivatives such as cellulose, methyl cellulose, cellulose acetate, cellulose nitrate, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose; polyvinyl alcohol, polyvinyl polyvinyl acetate derivatives such as butyral, polyvinyl formal and polyvinyl acetate; nitrogen-containing polymer derivatives such as polyvinylpyridine, polyvinylpyrrolidone, polyethyleneimine and poly-2-methyl-2-oxazoline; polyvinyl chloride and polyvinylidene chloride Vinyl halide derivatives; various hydrophobic or hydrophilic dispersants and stabilizers such as polysiloxane derivatives such as polydimethylsiloxane. These can be used individually by 1 type or in combination of 2 or more types.

Examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, condensates of polyethylene glycol and polypropylene glycol, sorbitan fatty acid esters (sorbitan monooleate, sorbitan monolaurate, sorbitan sesquioleate, sorbitan trioleate, etc.), polyoxyethylene sorbitan fatty acid esters (polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, etc.), polyethylene glycol fatty acid esters (polyoxyethylene monostearate, polyethylene glycol diisostearate, etc.) ), fatty acid monoglycerides, and condensation products of ethylene oxide and aliphatic amines. These can be used singly or in combination of two or more.

The production method of the present invention preferably includes a polymerization step of precipitation polymerization or dispersion polymerization of a monomer component containing 50 to 100% by mass of the monomer (I) and 0 to 20% by mass of the crosslinkable monomer. . Through the polymerization step, 50 to 100% by mass of the structural unit (A) derived from the monomer (I) is introduced into the crosslinked polymer.

The mass ratio of monomer (I) may be 25 to 99.9% by mass, or 40 to 99.5% by mass, in the total constituent monomers when a crosslinkable monomer is included. When the crosslinkable monomer is not included, the content may be 25 to 100% by mass, and may be 50 to 99.9% by mass.

When a crosslinkable monomer is included, the mass ratio is preferably 0 to 50% by mass, more preferably 0.1 to 25% by mass, more preferably 0.5 in all constituent monomers. to 20% by mass, more preferably 1 to 15% by mass.

The mass ratio of the monomer having a carboxy group and an ethylenically unsaturated group may be less than 50% by mass, may be 25% by mass or less, and may be 5% by mass or less in all constituent monomers. good.

The mass ratio of the compound (monomer) having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group may not be contained at all, and is 0.01 to 25% by mass in all constituent monomers. you can
Polymerizable monomers other than the above may not be contained at all, and when they are contained, the mass ratio may be 0.01 to 25% by mass.

In addition, the average particle size of the hydroxyl group-containing polymer obtained by the above production method is an average particle size of 1 to 1000 nm as the polymer particle size, preferably 10 to 900 nm, more preferably 10 to 900 nm, in order to form a uniform coating film. is between 50 and 800 nm, particularly preferably between 100 and 700 nm.

As the polymerization initiator, known polymerization initiators such as azo compounds, organic peroxides, and inorganic peroxides can be used, but the polymerization initiator is not particularly limited. Using known methods such as thermal initiation, redox initiation using a reducing agent, and UV initiation can be used to adjust the conditions of use so that an appropriate amount of radicals is generated. In order to obtain a crosslinked polymer having a long primary chain length, it is preferable to set the conditions so that the amount of radical generation is less within the allowable production time.

Examples of the azo compounds include 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(N-butyl-2-methylpropionamide), 2-(tert-butylazo)-2 -Cyanopropane, 2,2'-azobis (2,4,4-trimethylpentane), 2,2'-azobis (2-methylpropane) and the like, one or more of which are used be able to.

Examples of the organic peroxide include 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane (manufactured by NOF Corporation, trade name "Pertetra A"), 1,1-di(t- Hexylperoxy)cyclohexane (“Perhexa HC” in the same), 1,1-di(t-butylperoxy)cyclohexane (“Perhexa C” in the same), n-butyl-4,4-di(t-butylperoxy) Valerate ("Perhexa V"), 2,2-di(t-butylperoxy)butane ("Perhexa 22"), t-butyl hydroperoxide ("Perbutyl H"), cumene hydroperoxide (Japanese Yusha, trade name "Perocta H"), 1,1,3,3-tetramethylbutyl hydroperoxide ("Perocta H"), t-butyl cumyl peroxide ("Perbutyl C"), di- t-butyl peroxide (same as "Perbutyl D"), di-t-hexyl peroxide (same as "Perhexyl D"), di(3,5,5-trimethylhexanoyl) peroxide (same as "Perloyl 355"), dilauroyl peroxide (“Perloyl L”), bis(4-t-butylcyclohexyl) peroxydicarbonate (“Perloyl TCP”), di-2-ethylhexyl peroxydicarbonate (“Perloyl OPP”), Di-sec-butyl peroxydicarbonate (“Perloyl SBP”), cumyl peroxyneodecanoate (“Percumyl ND”), 1,1,3,3-tetramethylbutyl peroxyneodecanoate ( t-hexyl peroxyneodecanoate (Perocta ND), t-butyl peroxyneodecanoate (Perbutyl ND), t-butyl peroxyneoheptanoate (“Perbutyl NHP” in the same), t-hexyl peroxypivalate (“Perbutyl PV” in the same), t-butyl peroxypivalate (“Perbutyl PV” in the same), 2,5-dimethyl-2,5-di( 2-ethylhexanoyl)hexane (“Perhexa 250” in the same), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (“Perocta O” in the same), t-hexylperoxy-2 -Ethylhexanoate (“Perhexyl O” in the same), t-butyl peroxy-2-ethylhexanoate (“Perbutyl O” in the same), t-butyl peroxylaurate (“Perbutyl L” in the same), t- Spot luperoxy-3,5,5-trimethylhexanoate (the same "Perbutyl 355"),
t-hexylperoxyisopropyl monocarbonate (“Perbutyl I” in the same), t-butyl peroxyisopropyl monocarbonate (“Perbutyl I” in the same), t-butylperoxy-2-ethylhexyl monocarbonate (“Perbutyl E” in the same) , t-butyl peroxyacetate (“Perbutyl A” in the same), t-hexyl peroxybenzoate (“Perhexyl Z” in the same) and t-butyl peroxybenzoate (“Perbutyl Z” in the same). 1 type or 2 types or more can be used.

Examples of the inorganic peroxides include potassium persulfate, sodium persulfate and ammonium persulfate.

In the case of redox initiation, sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, sulfurous acid gas (SO ₂ ), ferrous sulfate, etc. can be used as reducing agents.

A preferred amount of the polymerization initiator used is 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass, and still more preferably 100 parts by mass of the total amount of the monomer components used. is 0.01 to 0.1 parts by mass. When the amount of the polymerization initiator used is 0.001 parts by mass or more, the polymerization reaction can be stably carried out, and when it is 2 parts by mass or less, it is easy to obtain a polymer having a long primary chain length.

The concentration of the monomer component during polymerization is preferably higher from the viewpoint of obtaining a polymer having a longer primary chain length. However, if the concentration of the monomer component is too high, aggregation of the polymer particles is likely to proceed, and it is difficult to control the heat of polymerization, which may cause the polymerization reaction to go out of control. Therefore, the monomer concentration at the start of polymerization is generally in the range of about 2 to 30% by mass, preferably in the range of 5 to 30% by mass.

The polymerization temperature is preferably 0 to 100.degree. C., more preferably 20 to 80.degree. C., although it depends on the type and concentration of the monomers used. The polymerization temperature may be constant or may vary during the polymerization reaction. The polymerization time is preferably 1 minute to 20 hours, more preferably 1 hour to 10 hours.

The crosslinked polymer dispersion obtained through the polymerization step is subjected to decompression and/or heat treatment in the drying step to remove the solvent or freeze-dry, thereby obtaining the target crosslinked polymer in a powder state. . At this time, before the drying step, for the purpose of removing unreacted monomers (and salts thereof), following the polymerization step, purification with a dialysis membrane, solid-liquid separation steps such as centrifugation and filtration, organic solvent Alternatively, it is preferable to include a washing step using a mixed solvent of organic solvent/water.

When the washing step is provided, even if the crosslinked polymer is secondary aggregated, it is easily disintegrated during use, and the remaining unreacted monomer is removed, so that the binding property and battery characteristics are good. performance.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited by the following examples. In the following, "parts" and "%" mean parts by mass and % by mass unless otherwise specified.

(Production example 1)
In a reaction vessel equipped with a gas inlet tube, a thermometer, and a cooling tube, 50 parts of glycerol monoacrylate, 50 parts of acrylic acid, 15 parts of pentaerythritol triacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate PE-3A), solvent 1,000 parts of acetonitrile was charged as a solution, and stirring and heating were started while nitrogen gas was flowed. At an internal temperature of 60° C., 2,2′-azobis(2,4-dimethylvaleronitrile) (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: V-65) was added to initiate polymerization. White turbidity due to precipitation of polymer particles was observed 5 minutes after the start of polymerization, and the reaction was further continued with stirring for 7 hours. After cooling the reaction solution to room temperature, the particles were sedimented by centrifugation and the supernatant was removed. To the obtained particles, a 2% sodium hydroxide ethanol solution was added so that the neutralization rate of the charged acrylic acid was 70%, followed by ultrasonic dispersion for 5 minutes, followed by centrifugation again to collect the particles. Furthermore, ethanol was added, dispersion and centrifugation were repeated twice, and a washing operation was performed to remove residual monomers and excess sodium hydroxide. The resulting particle slurry was dried in a hot air dryer at 80° C. and pulverized in a mortar to obtain a desired dry powder of resin particles A-1.

(Production Examples 2 to 8)
Resin particles A-2 to A-6 and B-1 to B-2 were prepared in the same manner as in Production Example 1, except that the types and amounts of raw material monomers used and the neutralization rate were changed as shown in Table 1. Obtained.

(Production Example 9) 140 parts of cyclohexane and 10 parts of sorbitan monostearate as a dispersant were placed in a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a dropping funnel, and dissolved in nitrogen gas. was blown to remove dissolved oxygen. In a separate vessel, 28.2 parts of sodium acrylate, 7.2 parts of acrylic acid, 5 parts of glycerol dimethacrylate, and 0.006 parts of N-methylenebisacrylamide are dissolved in 60 parts of deionized water, and then 0.2 parts of potassium persulfate is added. 05 parts was added and dissolved, then added to 140 parts of cyclohexane containing 10 parts of sorbitan monostearate and stirred for 5 minutes with a homomixer to prepare a pre-emulsion. This pre-emulsion was slowly added dropwise to the reaction vessel heated to 60° C. to carry out reverse-phase suspension polymerization. After reacting at 60° C. for 2 hours, water was distilled off by azeotropic dehydration. The cyclohexane phase was removed from the reaction solution cooled to room temperature by centrifugation and decantation. The resulting slurry was dried with a hot air dryer at 80° C. and pulverized with a mortar to obtain resin particles B-3. The average particle size of resin particles B-3 was 15 μm.

GLMA: glycerol monoacrylate
GLMM: glycerol monomethacrylate
DHPMA: 2,3-dihydroxypropyl methacrylamide
AA: acrylic acid
HEMA: Hydroxyethyl methacrylate
PE-3A: Pentaerythritol triacrylate
GLDM: glycerol dimethacrylate

(Volume average particle size of resin particles)
The polymerization particle size of the resin particles was obtained by diluting the reaction solution 1000 times by mass with acetonitrile as a measurement sample. The dry powder particle diameter was measured by adding 10 parts by mass of purified water to 0.001 part by mass of the obtained powder resin particles and dispersing the mixture with ultrasonic waves for 10 minutes. Each measurement sample was measured by a dynamic light scattering method using a particle size distribution analyzer (manufactured by Malvern, "Zetasizer Ultra ZSU5700") to determine the volume average particle size.

(Examples 1 to 6, Comparative Examples 1 to 3)
The resin particles A-1 to A6 and B-1 to B-3 were evaluated for metal adhesion and antifogging properties. Table 2 shows the results.

(Evaluation of metal adhesion)
9.7 parts of purified water was added to 0.3 parts of resin particles, and the mixture was ultrasonically dispersed for 10 minutes to prepare a 3% particle dispersion. The particle dispersion was applied to a copper test plate (copper plate JIS H3100) to a thickness of 200 μm and dried in an oven at 80° C. to form a coating film.
An adhesive tape was adhered to the resulting coating film and then peeled off to evaluate the degree of peeling. A or B is preferred.
A: No peeling.
B: Part of the coating film is peeled off.
C: Large peeling occurred over the entire surface.

(Anti-fogging property evaluation)
A 3% particle dispersion was applied to the surface of a glass plate using an applicator to a thickness of 200 μm and dried in an oven at 80° C. to prepare a coating substrate.
Antifogging properties were evaluated based on the following evaluation criteria, in which breath was blown onto the coating substrate at room temperature and the presence or absence of fogging on the surface was visually evaluated. A or B is preferred.
A: No haze B: Slight haze C: The entire surface of the coating was haze

Claims (5)

A hydroxyl-containing polymer having an average particle diameter of 1 to 1000 nm and having a group represented by the following formula (I).
*-Y-Z (I)
(In formula (I), Z is a monovalent group in which two or more hydrogen atoms of a monovalent hydrocarbon group having 3 to 8 carbon atoms are substituted with hydroxyl groups, and Y is an oxygen atom or —NH -, and * represents the bonding position of the monovalent group.) The polymer contains a structural unit (A) derived from a monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group, and the structural unit ( 2. The hydroxyl group-containing polymer according to claim 1, containing 50% by mass or more of A). 3. The hydroxyl group-containing polymer according to claim 1, wherein the polymer contains a structural unit derived from a crosslinkable monomer. 4. The hydroxyl group-containing polymer according to claim 2 or 3, wherein said structural unit (A) is derived from glycerol (meth)acrylate or dihydroxypropyl (meth)acrylamide. A method for producing a hydroxyl group-containing polymer, wherein a monomer component containing a monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group and a crosslinkable monomer is subjected to precipitation polymerization or A method for producing the hydroxyl group-containing polymer, comprising a polymerization step of dispersion polymerization.