Hydroxyl-containing polymer and method for producing the same

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]

[0001] The present invention relates to resin particles having excellent hydrophilicity and a method for producing the same. [Background technology]

[0002] Microparticles containing hydrophilic polymers are used in various fields. Microparticulation is required from the viewpoint of transparency, etc., and a crosslinked polymer having a carboxyl group is known as a resin that has been microparticulated to the submicron order (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6150031 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as a result of intensive research by the present inventors, it was found that although a crosslinked polymer having a carboxyl group has sufficient hydrophilicity, it has insufficient adhesion to metals and the like, and there is still room for improvement in terms of use in various applications such as medical, cosmetic, and industrial applications. [Means for solving the problem]

[0005] In this specification, the term "α-β" indicating a range means "above α and below β". In this specification, "acid (salt)" means "acid and / or its salt". "(Meth)acrylic" means "acrylic and / or methacrylic".

[0006] The hydroxyl-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). *-YZ···(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 have been substituted with hydroxyl groups, Y is an oxygen atom or -NH-, and * represents the bonding position of the monovalent group.)

[0007] The polymer contains structural units (A) derived from monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group, and preferably contains 50 mass % or more of structural units (A) based on the total amount of the polymer.

[0008] The polymer preferably contains a structural unit derived from a crosslinkable monomer.

[0009] The structural unit (A) of the polymer is preferably derived from glycerol (meth)acrylate or dihydroxypropyl (meth)acrylamide.

[0010] The above-mentioned hydroxyl group-containing polymer preferably comprises a polymerization step of precipitation polymerization of a monomer component containing a crosslinkable monomer and a monomer (I) having a group represented by formula (I) and an ethylenically unsaturated group. Effect of the Invention

[0011] According to the present invention, it is possible to provide a hydroxyl-containing polymer of the submicron order that is hydrophilic and has excellent adhesion to a substrate, and a method for producing the hydroxyl-containing polymer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Hydroxyl Group-Containing Polymer) The hydroxyl group-containing polymer of the present embodiment has an average particle diameter of 1 to 1000 nm, and in order to form a uniform coating film, it is preferably 10 to 900 nm, more preferably 50 to 800 nm, and particularly preferably 100 to 700 nm. The average particle diameter of the hydroxyl group-containing polymer is the volume average particle diameter of the polymerized particles, that is, the polymerized particle diameter, and can be measured specifically by the dynamic light scattering method described in the Examples. In this specification, the polymerized particles mean particles that exist in the reaction medium after the reaction when produced by various polymerization methods, and are different from the dry powder particles obtained by drying after the reaction. In the case of dry powder particles, the influence of swelling due to the dispersion solvent and secondary aggregation is large, but the volume average particle diameter of those dry powder particles, that is, the particle diameter when dispersed in water, is 0.1 μm to 10 μm, and preferably 0.2 μm to 5 μm. It can be measured by the dynamic light scattering method described in the Examples in the same manner as the polymerized particle diameter.

[0013] The coefficient of variation (CV value, standard deviation of particle diameter divided by number average particle diameter) of the particle diameter of the hydroxyl group-containing polymer is preferably 1 to 20%, and more preferably 1 to 10%.

[0014] The hydroxyl group-containing polymer of the present embodiment has hydrophilicity and adhesion to a substrate, and therefore can be used in industrial applications as an additive that imparts anti-fogging properties and / or hydrophilicity, an anti-condensation additive, an antifouling material, a thickener, a chelating agent (ion adsorbent), paints, and various additives and binders for electric and electronic materials, as well as a thickener, a water retention agent, a drug carrier, a carrier for a drug delivery system in the medical field, a nanogel material, and the like.

[0015] The hydroxyl group-containing polymer of the present embodiment contains a hydroxyl group-containing polymer.

[0016] The hydroxyl-containing polymer of this embodiment has a group represented by the above formula (I). In formula (I), the carbon number of Z is preferably 3 to 6, and more preferably 3 to 5. The number of hydroxyl groups that Z has is preferably 2 or 3, and more preferably 2.

[0017] The hydroxyl-containing polymer is not particularly limited as long as it is a polymer having a group represented by the above formula (I). 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, or a combination thereof. The hydroxyl-containing polymer may be a homopolymer or a copolymer. The group represented by formula (I) may be bonded to the end of the hydroxyl-containing polymer (I), or may be bonded to a portion other than the end. When the hydroxyl-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 natural polymer such as gelatin, hyaluronic acid, or alginic acid into which a group represented by formula (I) has been introduced can also be used as the hydroxyl-containing polymer.

[0018] The hydroxyl-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 even more preferably 0.005 mol / g or more, where the unit mol / g is the number of moles of the group represented by formula (I) per gram of the hydroxyl-containing polymer.

[0019] 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)). The "structural unit derived from monomer (I)" refers not only to a structural unit obtained by polymerizing monomer (I), but also to a structural unit obtained by a method other than polymerizing monomer (I), as long as the structural unit has the same structure as the structural unit obtained by polymerizing monomer (I). For example, a structural unit obtained by deprotecting the hydroxyl group in the Z group of monomer (I) after polymerization of monomer (I) is the same structural unit as that obtained by polymerizing monomer (I), and is therefore included in the "structural unit derived from monomer (I)". In addition, when the Z group of monomer (I) has multiple hydroxyl groups, a monomer in which two of the hydroxyl groups form a cyclic ether structure by intramolecular dehydration is polymerized, and then the cyclic ether structure is hydrolyzed with an acid or the like to return to the hydroxyl groups. This structural unit has the same structure as when monomer (I) is polymerized, and is therefore included in the "structural unit derived from monomer (I)".

[0020] The monomer (I) is preferably a compound represented by the following formula (IA).

[0021] [ka] (IA)

[0022] (In formula (IA), Z and Y have the same meanings as Z and Y in formula (I), and R represents a hydrogen atom or a methyl group.) Z is preferably a group represented by the following formula (II):

[0023] [ka] (II)

[0024] (In formula (II), R 1 is -CH(OH)CHOH or -CHOH, R2 is a hydrogen atom or -CHOH, and R 3 is a hydrogen atom or -CHOH, and * represents the bonding position of the group represented by formula (II). As the monomer (I), glycerol mono(meth)acrylate, 2,3-dihydroxypropyl(meth)acrylamide, and 1,3-dihydroxypropyl(meth)acrylamide are preferred, and glycerol mono(meth)acrylate is more preferred.

[0025] The structural unit derived from the monomer (I) also includes a structural unit derived from a monomer that can be (co)polymerized and then hydrolyzed to generate a hydroxyl group, such as the following monomer (IB):

[0026] [ka] (IB)

[0027] (In formula (IB), R 11 represents a hydrogen atom or a methyl group, R 13 and R 14 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. When the monomer (IB) is polymerized and then treated with acid, the dioxolane ring is hydrolyzed, generating two hydroxyl groups in the structural unit.

[0028] The hydroxyl-containing polymer may be a copolymer of the monomer (I) and other monomers including a crosslinkable monomer.

[0029] (Cross-linking monomer) Examples of the crosslinkable monomer include polyfunctional polymerizable monomers having two or more polymerizable unsaturated groups, and monomers having a self-crosslinkable crosslinkable functional group such as a hydrolyzable silyl group. The polyfunctional polymerizable monomer is a compound having two or more polymerizable functional groups such as (meth)acryloyl group, alkenyl group, etc. in the molecule, and examples thereof include polyfunctional (meth)acrylate compounds, polyfunctional alkenyl compounds, compounds having both (meth)acryloyl group and alkenyl group, etc. These compounds may be used alone or in combination of two or more. Among these, polyfunctional alkenyl compounds are preferred in that they are easy to obtain a uniform crosslinked structure, and polyfunctional allyl ether compounds having multiple allyl ether groups in the molecule are particularly preferred.

[0030] Examples of the polyfunctional (meth)acrylate compound include di(meth)acrylates of dihydric alcohols such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate; tri(meth)acrylates of trihydric or higher polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, tri(meth)acrylate of an ethylene oxide modified trimethylolpropane, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; and poly(meth)acrylates such as tetra(meth)acrylate; and bisamides such as methylene bisacrylamide and hydroxyethylene bisacrylamide.

[0031] Examples of polyfunctional alkenyl compounds include polyfunctional allyl ether compounds such as trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, tetraallyloxyethane, and polyallylsucrose; polyfunctional allyl compounds such as diallyl phthalate; and polyfunctional vinyl compounds such as divinylbenzene. Examples of 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 2-(2-vinyloxyethoxy)ethyl (meth)acrylate.

[0032] Specific examples of the monomer having a self-crosslinkable crosslinkable functional group include a hydrolyzable silyl group-containing vinyl monomer, N-methylol (meth)acrylamide, N-methoxyalkyl (meth)acrylate, etc. These compounds can be used alone or in combination of two or more.

[0033] The vinyl monomer containing hydrolyzable silyl group is not particularly limited as long as it is a vinyl monomer having at least one hydrolyzable silyl group.For example, vinyl silanes such as vinyl trimethoxysilane, vinyl triethoxysilane, vinyl methyl dimethoxysilane, vinyl dimethyl methoxysilane, etc.; silyl group-containing acrylic acid esters such as trimethoxysilylpropyl acrylate, triethoxysilylpropyl acrylate, methyl dimethoxysilylpropyl acrylate, etc.; silyl group-containing methacrylic acid esters such as trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, methyl dimethoxysilylpropyl methacrylate, dimethyl methoxysilylpropyl methacrylate, etc.; silyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether, etc.; silyl group-containing vinyl esters such as vinyl trimethoxysilyl undecanoate, etc.

[0034] In order to obtain particles that are easy to handle as a powder and have flexibility, di(meth)acrylates of dihydric alcohols, tri(meth)acrylates and tetra(meth)acrylates of trihydric or higher polyhydric alcohols are preferred.

[0035] When the hydroxyl-containing polymer of the present invention is crosslinked by a crosslinkable monomer, the amount of the crosslinkable monomer used is preferably 0.01 to 40 mol %, more preferably 0.1 to 10 mol %, based on the total amount of monomers other than the crosslinkable monomer (non-crosslinkable monomer). If 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 better. If it is 40 mol % or less, the stability of the hydroxyl-containing polymer tends to be high. In addition, the amount of the crosslinkable monomer used is preferably 0 to 50 mass %, more preferably 0.1 to 25 mass %, even more preferably 0.5 to 20 mass %, and even more preferably 1 to 105 mass % of the total constituent monomers of the hydroxyl-containing polymer. In this specification, the total constituent monomers specifically refer to the total amount of monomers including the monomer (I) used in the polymerization.

[0036] (Monomers other than crosslinkable monomers) The other monomers include crosslinkable monomers and compounds having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group.

[0037] Further, examples of other monomers include neutral hydrophilic monomers such as (meth)acrylamide, N-alkyl(meth)acrylamides (e.g., N,N-dimethyl(meth)acrylamide), N-vinylpyrrolidone, N-vinylpyrrolidinone, N-vinylacetamide, N-vinylformamide, hydroxyethyl(meth)acrylate, and hydroxypropyl(meth)acrylate; anionic hydrophilic monomers such as (meth)acrylic acid or a salt thereof, maleic acid or a salt thereof, fumaric acid or a salt thereof, itaconic acid or a salt thereof, (meth)acrylamidomethylpropanesulfonic acid or a salt thereof, vinylphosphonic acid or a salt thereof, and vinylbenzoic acid or a salt thereof; and cationic hydrophilic monomers such as 3-aminopropyl(meth)acrylamide (APMA), (meth)acrylamidopropyltrimethylammonium chloride (MAPTAC), and N,N-dimethylaminoethyl(meth)acrylate.

[0038] Examples of other monomers include hydrophobic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, methoxyethyl (meth)acrylate, and styrene, and reactive group-containing monomers such as glycidyl (meth)acrylate, isopropenyl oxazoline, vinyl oxazoline, and maleic anhydride.

[0039] The other monomers may be used alone or in combination of two or more.

[0040] The content of the structural unit derived from the monomer having a carboxy group and an ethylenically unsaturated group in the hydroxyl group-containing polymer may be less than 50% by mass, may be 25% by mass or less, or may be 5% by mass or less, based on the total amount of the hydroxyl group-containing polymer (I). The structural unit derived from the monomer having a carboxy group and an ethylenically unsaturated group may be a structural unit obtained by polymerizing the monomer, but may also be a structural unit obtained by a method other than polymerizing the monomer, so long as it has the same chemical structure (for example, a structural unit obtained by polymerizing a corresponding ester compound, hydrolyzing the ester group to form a carboxy group, etc.).

[0041] An example of the compound having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group is a compound represented by the following formula (III).

[0042] [ka] (III)

[0043] In the above formula (III), A represents a hydrogen atom or an organic group having 1 to 20 carbon atoms, X represents -C(=O)-, -CH2-, -CH2CH2-, -CH2CH2CH2- or 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 is a number of 1 to 200, k represents a hydrogen atom or an organic group having 1 to 20 carbon atoms which may have a substituent.

[0044] Above A and A k are each 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 more preferably a hydrogen atom or an organic group having 1 to 4 carbon atoms. When the organic group has a substituent, it is more preferable that the number of carbon atoms including the substituent is within the above range. k It is even more preferable that each is a hydrogen atom or a methyl group.

[0045] The above Q is preferably an alkylene group having 2 to 5 carbon atoms, and more preferably an ethylene group, an n-propylene group, or an isopropylene group. Q may contain only one type of alkylene group, or may contain two or more types of alkylene groups. When Q contains an ethylene group, it is preferable that 50 to 100 mol % of the total alkylene glycol units in the polyalkylene glycol group are ethylene groups, more preferably 80 to 100 mol %, and more preferably 90 to 100 mol % are ethylene groups.

[0046] m may be the average number of moles added for all the compounds represented by formula (III). m is preferably 1 to 100, more preferably 5 to 80, and further preferably 10 to 60.

[0047] When X is represented by -C(=O)-, examples of the compound include adducts of alkylene oxides having 1 to 100 carbon atoms to (meth)acrylic acid: esters of alkoxypolyalkylene glycols obtained by adding alkylene oxides having 1 to 100 carbon atoms to alkyl alcohols having 1 to 30 carbon atoms, such as methanol, ethanol, 2-propanol, and 1-butanol, with (meth)acrylic acid.

[0048] When X is represented by -CH2-, -CH2CH2-, or -CH2CH2CH2-, examples of the compound include compounds having a structure in which 1 to 100 moles of alkylene oxide are added to an unsaturated alcohol such as 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, or vinyl alcohol, and one or more of these may be used.

[0049] Further, examples of the compound represented by formula (III) include polyalkylene oxide chain-containing (meth)acrylic acid esters such as 2-ethylhexyl carbitol (meth)acrylate, and alkoxyalkyl (meth)acrylic acid esters such as methoxybutyl (meth)acrylate, methoxyethyl (meth)acrylate, and ethoxybutyl (meth)acrylate.

[0050] The content of the structural unit derived from the monomer (I) in the hydroxyl-containing polymer may be 25 to 99.9% by mass, or 40 to 99.5% by mass, when the hydroxyl-containing polymer contains a crosslinkable monomer. The content of the structural unit derived from the monomer (I) in the hydroxyl-containing polymer may be 25 to 100% by mass, or 50 to 99.9% by mass, when the hydroxyl-containing polymer does not contain a crosslinkable monomer. When the hydroxyl-containing polymer contains a structural unit derived from a compound having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group, the content of the structural unit may be 0.01 to 25% by mass, based on the total amount of the hydroxyl-containing polymer (I).

[0051] (Method of producing hydroxyl-containing polymer) The hydroxyl group-containing polymer of the present invention can be prepared by known polymerization methods such as solution polymerization, precipitation polymerization, dispersion polymerization, suspension polymerization, and reversed-phase emulsion polymerization, but from the viewpoint of productivity, precipitation polymerization, dispersion polymerization, and suspension polymerization (reverse-phase suspension polymerization) are preferred. In terms of obtaining better performance in terms of binding property, etc., precipitation polymerization or dispersion polymerization is more preferred, and precipitation polymerization is particularly preferred.

[0052] Precipitation polymerization is a method for producing polymers by carrying out a polymerization reaction in a solvent that dissolves the raw material unsaturated monomers but does not substantially dissolve the resulting polymer. As the polymerization proceeds, the polymer particles become larger through aggregation and growth, and a dispersion of polymer particles is obtained in which primary particles of tens to hundreds of nm are secondary aggregated to several μm to several tens of μm.

[0053] The secondary aggregation can be suppressed by selecting a dispersion stabilizer, a polymerization solvent, etc. In general, precipitation polymerization in which secondary aggregation is suppressed is called dispersion polymerization, and although the two are sometimes distinguished, in a broad sense, they can be called precipitation polymerization.

[0054] In the case of precipitation polymerization, the polymerization solvent may be selected from water and various organic solvents, etc., taking into consideration the type of monomer to be used, etc. In order to obtain a polymer having a longer primary chain length, it is preferable to use a solvent having a small chain transfer constant.

[0055] 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, and these can be used alone or in combination of two or more. Alternatively, these can be used as a mixed solvent with water. In the present invention, the water-soluble solvent refers to a solvent having a solubility in water of more than 10 g / 100 ml at 20° C.

[0056] Among the above, acetonitrile is preferred because it has good polymerization stability with little generation of coarse particles and little adhesion to the reactor, the precipitated polymer fine particles are not prone to secondary aggregation (or even if secondary aggregation does occur, it is easily disintegrated in an aqueous medium), a polymer having a small chain transfer constant and a large degree of polymerization (primary chain length) can be obtained, and the operation is easy during the neutralization step described below.

[0057] Similarly, in order to stably and rapidly proceed with the neutralization reaction in the neutralization step, it is preferable to add a small amount of a highly polar solvent to the polymerization solvent. Such highly polar solvents are preferably 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, and even more preferably 0.1 to 1.0% by mass, based on the total mass of the medium. If the proportion of the highly polar solvent is 0.05% by mass or more, an effect on the neutralization reaction is observed, and if it is 10.0% by mass or less, no adverse effect on the polymerization reaction is observed.

[0058] In the case of dispersion polymerization, as in the case of precipitation polymerization, a polymerization solvent may be used that is selected from water and various organic solvents, etc., taking into consideration the type of monomer to be used, etc., and a dispersion stabilizer for suppressing secondary aggregation may be used.

[0059] Specific examples of the dispersion stabilizer that can be used include polymeric dispersants and nonionic emulsifiers. Examples of polymer-type dispersants include polystyrene derivatives such as polyhydroxystyrene, polystyrene sulfonic acid, vinylphenol-(meth)acrylic acid ester copolymer, styrene-(meth)acrylic acid ester copolymer, and styrene-vinylphenol-(meth)acrylic acid ester copolymer; poly(meth)acrylic acid derivatives such as poly(meth)acrylic acid, poly(meth)acrylamide, polyacrylonitrile, polyethyl(meth)acrylate, and polybutyl(meth)acrylate; polyvinyl alkyl ether derivatives such as polymethyl vinyl ether, polyethyl vinyl ether, polybutyl vinyl ether, and polyisobutyl vinyl ether; and cellulose. Examples of the hydrophobic or hydrophilic dispersants and stabilizers include cellulose derivatives such as methyl cellulose, cellulose acetate, cellulose nitrate, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose; polyvinyl acetate derivatives such as polyvinyl alcohol, polyvinyl butyral, polyvinyl formal, and polyvinyl acetate; nitrogen-containing polymer derivatives such as polyvinylpyridine, polyvinylpyrrolidone, polyethyleneimine, and poly-2-methyl-2-oxazoline; polyvinyl halide derivatives such as polyvinyl chloride and polyvinylidene chloride; and polysiloxane derivatives such as polydimethylsiloxane. These may be used alone or in combination of two or more.

[0060] 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, condensates of ethylene oxide and aliphatic amines, etc. These can be used alone or in combination of two or more.

[0061] 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 mass% of the monomer (I) and 0 to 20 mass% of a crosslinkable monomer, whereby 50 to 100 mass% of the structural unit (A) derived from the monomer (I) is introduced into the crosslinked polymer.

[0062] The mass ratio of the monomer (I) may be 25 to 99.9 mass % or 40 to 99.5 mass % of all constituent monomers when a crosslinkable monomer is contained, and may be 25 to 100 mass % or 50 to 99.9 mass % when no crosslinkable monomer is contained.

[0063] When a crosslinkable monomer is contained, its mass ratio in all constituent monomers is preferably 0 to 50 mass%, more preferably 0.1 to 25 mass%, even more preferably 0.5 to 20 mass%, and even more preferably 1 to 15 mass%.

[0064] The mass ratio of the monomer having a carboxy group and an ethylenically unsaturated group in all the constituent monomers may be less than 50 mass%, may be 25 mass% or less, or may be 5 mass% or less.

[0065] The mass ratio of a compound (monomer) having an ethylenically unsaturated group and an alkylene glycol group or a polyalkylene glycol group may be zero or may be 0.01 to 25% by mass in all the constituent monomers. The composition may not contain any polymerizable monomers other than those mentioned above, and when contained, the mass ratio thereof may be 0.01 to 25 mass %.

[0066] The average particle size of the hydroxyl group-containing polymer obtained by the above production method is 1 to 1000 nm as the polymerized particle size, and in order to form a uniform coating film, it is preferably 10 to 900 nm, more preferably 50 to 800 nm, and particularly preferably 100 to 700 nm.

[0067] The polymerization initiator may be any known polymerization initiator such as an azo compound, an organic peroxide, or an inorganic peroxide, but is not particularly limited. The conditions of use may be adjusted so that an appropriate amount of radicals is generated by known methods such as thermal initiation, redox initiation using a reducing agent, or UV initiation. In order to obtain a crosslinked polymer with a long primary chain length, it is preferable to set the conditions so that the amount of radicals generated is as small as possible within the allowable range of production time.

[0068] Examples of the azo compound 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 these may be used.

[0069] Examples of the organic peroxides include 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane (manufactured by NOF Corporation, trade name "Pertetra A"), 1,1-di(t-hexylperoxy)cyclohexane (manufactured by NOF Corporation, trade name "Perhexa HC"), 1,1-di(t-butylperoxy)cyclohexane (manufactured by NOF Corporation, trade name "Perhexa C"), n-butyl-4,4-di(t-butylperoxy)valerate (manufactured by NOF Corporation, trade name "Perhexa V"), 2,2-di(t-butylperoxy)butane (manufactured by NOF Corporation, trade name "Perhexa 22"), t-Butyl hydroperoxide ("Perbutyl H"), cumene hydroperoxide (manufactured by NOF Corporation, trade name "Percumyl H"), 1,1,3,3-tetramethylbutyl hydroperoxide ("Perocta H"), t-butylcumyl peroxide ("Perbutyl C"), di-t-butyl peroxide ("Perbutyl D"), di-t-hexyl peroxide ("Perhexyl D"), di(3,5,5-trimethylhexanoyl) peroxide ("Perbutyl H"), Peroyl 355), dilauroyl peroxide (Peroyl L), bis(4-t-butylcyclohexyl) peroxydicarbonate (Peroyl TCP), di-2-ethylhexyl peroxydicarbonate (Peroyl OPP), di-sec-butyl peroxydicarbonate (Peroyl SBP), cumyl peroxyneodecanoate (Percumyl ND), 1,1,3,3-tetramethylbutyl peroxyneodecanoate (Peroyl SBP), Octa ND), t-hexyl peroxyneodecanoate (Perhexyl ND), t-butyl peroxyneodecanoate (Perbutyl ND), t-butyl peroxyneoheptanoate (Perbutyl NHP), t-hexyl peroxypivalate (Perhexyl PV), t-butyl peroxypivalate (Perbutyl PV), 2,5-dimethyl-2,5-di(2-ethylhexanoyl)hexane (Perhexa 250), 1,1,3,3-Tetramethylbutylperoxy-2-ethylhexanoate (Perocta O), t-hexylperoxy-2-ethylhexanoate (Perhexyl O), t-butylperoxy-2-ethylhexanoate (Perbutyl O), t-butylperoxylaurate (Perbutyl L), t-butylperoxy-3,5,5-trimethylhexanoate (Perbutyl 355), Examples of such peroxyalkyl groups include t-hexylperoxyisopropyl monocarbonate ("Perhexyl I"), t-butylperoxyisopropyl monocarbonate ("Perbutyl I"), t-butylperoxy-2-ethylhexyl monocarbonate ("Perbutyl E"), t-butylperoxyacetate ("Perbutyl A"), t-hexylperoxybenzoate ("Perhexyl Z") and t-butylperoxybenzoate ("Perbutyl Z"), and one or more of these may be used.

[0070] Examples of the inorganic peroxide include potassium persulfate, sodium persulfate, and ammonium persulfate.

[0071] In the case of redox initiation, sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, sulfurous acid gas (SO2), ferrous sulfate, etc. can be used as reducing agents.

[0072] The amount of the polymerization initiator used is preferably 0.001 to 2 parts by mass, more preferably 0.005 to 1 part by mass, and even more preferably 0.01 to 0.1 part by mass, when the total amount of the monomer components used is 100 parts by mass. If the amount of the polymerization initiator used is 0.001 part by mass or more, the polymerization reaction can be stably carried out, and if it is 2 parts by mass or less, a polymer having a long primary chain length is easily obtained.

[0073] The concentration of the monomer component during polymerization is preferably high in order to obtain a polymer with a longer primary chain length. However, if the concentration of the monomer component is too high, the aggregation of polymer particles is likely to proceed, and the polymerization heat becomes difficult to control, and the polymerization reaction may runaway. For this reason, the monomer concentration at the start of polymerization is generally in the range of about 2 to 30 mass%, and preferably in the range of 5 to 30 mass%.

[0074] The polymerization temperature varies depending on conditions such as the type and concentration of the monomers used, but is preferably 0 to 100° C., more preferably 20 to 80° C. 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.

[0075] The crosslinked polymer dispersion obtained through the polymerization step can be subjected to reduced pressure and / or heat treatment in the drying step to distill off the solvent or freeze-dry to obtain the desired crosslinked polymer in powder form. In this case, it is preferable to provide a purification step using a dialysis membrane, a solid-liquid separation step such as centrifugation and filtration, or a washing step using an organic solvent or a mixed solvent of an organic solvent and water, following the polymerization step, for the purpose of removing unreacted monomers (and their salts) before the drying step.

[0076] When the above-mentioned washing step is provided, even if the crosslinked polymer undergoes secondary aggregation, it is easily disintegrated during use, and further, since the remaining unreacted monomer is removed, good performance is exhibited in terms of binding property and battery characteristics. EXAMPLES

[0077] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the following, "parts" and "%" mean parts by mass and % by mass, respectively, unless otherwise specified.

[0078] (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., product name: Light Acrylate PE-3A), and 1000 parts of acetonitrile as a solvent were charged, and stirring and heating were started while flowing nitrogen gas. At an internal temperature of 60°C, 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name: V-65) was added to start polymerization. Five minutes after the start of polymerization, white turbidity due to precipitation of polymer particles was observed, and the reaction was continued with stirring for another 7 hours. After cooling the reaction liquid to room temperature, the particles were precipitated by centrifugation, and the supernatant was removed. The particles obtained were mixed with 2% sodium hydroxide ethanol solution to achieve a neutralization rate of 70% relative to the acrylic acid charged, and ultrasonically dispersed for 5 minutes. The particles were then centrifuged again to recover the particles, and ethanol was added, followed by repeating dispersion and centrifugation 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 the desired dry powder of resin particles A-1.

[0079] (Production Examples 2 to 8) Resin particles A-2 to A-6 and B-1 to B-2 were obtained in the same manner as in Production Example 1, except that the types and amounts of raw material monomers and the neutralization rate were changed as shown in Table 1.

[0080] [Table 1]

[0081] (Production Example 9) 140 parts of cyclohexane and 10 parts of sorbitan monostearate as a dispersant were charged into a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen gas inlet tube, and a dropping funnel, and after dissolving, nitrogen gas was blown in to remove dissolved oxygen. In another 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 were dissolved in 60 parts of ion-exchanged water, and then 0.05 parts of potassium persulfate were added and dissolved, and then added to 140 parts of cyclohexane containing 10 parts of sorbitan monostearate, and stirred with a homomixer for 5 minutes to prepare a pre-emulsion. This pre-emulsion was slowly dropped into the reaction vessel heated to 60°C, and reverse phase suspension polymerization was carried out. After reacting at 60°C for 2 hours, water was distilled off by azeotropic dehydration. The cyclohexane phase was removed from the reaction liquid cooled to room temperature by centrifugation and decantation. The resulting slurry was dried in a hot air dryer at 80° C. and crushed in a mortar to obtain resin particles B-3. The resin particles B-3 had an average particle size of 15 μm.

[0082] GLMA: glycerol monoacrylate GLMM: glycerol monomethacrylate DHPMA: 2,3-dihydroxypropyl methacrylamide AA: Acrylic acid HEMA: Hydroxyethyl methacrylate PE-3A: Pentaerythritol triacrylate GLDM: glycerol dimethacrylate

[0083] (Volume average particle size of resin particles) The polymerized particle diameter of the resin particles was measured by diluting the reaction solution 1000 times by mass with acetonitrile. The dry powder particle diameter was measured by adding 10 parts by mass of purified water to 0.001 parts by mass of the obtained powder resin particles, and dispersing the mixture by ultrasonic waves for 10 minutes. Each measurement sample was measured by dynamic light scattering using a particle size distribution measuring device (manufactured by Malvern Instruments, "Zetasizer Ultra ZSU5700") to obtain the volume average particle diameter.

[0084] (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 anti-fogging properties. The results are shown in Table 2. TIFF0007672242000006.tif5491

[0085] (Metal adhesion evaluation) 0.3 parts of resin particles were mixed with 9.7 parts of purified water and dispersed for 10 minutes with ultrasonic waves 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 produce a coating film. An adhesive tape was attached to the obtained coating film and then peeled off, and the degree of peeling was evaluated. A: No peeling. B: Part of the coating peels off. C: Large peeling has occurred over the entire surface.

[0086] (Anti-fogging evaluation) The 3% particle dispersion was applied to the surface of a glass plate with an applicator to a thickness of 200 μm, and then dried in an oven at 80° C. to prepare a coated substrate. Breath was blown onto the coating substrate at room temperature, and the presence or absence of clouding on the surface was visually evaluated. The anti-fogging property was evaluated based on the following evaluation criteria, with A or B being preferred. A: There was no cloudiness. B: Slight cloudiness was observed C: The entire surface of the coating is cloudy.

Claims

1. A hydroxyl group-containing polymer having an average particle size of 1 to 1000 nm, The monomer (I) represented by the following formula (IA) contains a structural unit (A) in an amount of 40 to 99.5% by mass, Contains a structural unit derived from a crosslinkable monomer which is a polyfunctional (meth)acrylate compound or a polyfunctional alkenyl compound, Contains structural units derived from a crosslinkable monomer in a ratio of 0.5 to 20% by mass, The average particle size is 249 to 700 nm. The hydroxyl group-containing polymer. 【Chemistry 1】 (In formula IA, Z is a monovalent group in which two or more hydrogen atoms of a monovalent hydrocarbon group having 3 to 8 carbon atoms have been substituted with hydroxyl groups, Y is an oxygen atom or -NH-, and R is a hydrogen atom or a methyl group.)

2. 2. The hydroxyl group-containing polymer according to claim 1, wherein the structural unit (A) is derived from glycerol (meth)acrylate or dihydroxypropyl (meth)acrylamide.

3. 3. A method for producing the hydroxyl-containing polymer according to claim 1 or 2, comprising a polymerization step of subjecting a monomer component containing the monomer (I) and a crosslinkable monomer to precipitation polymerization or dispersion polymerization.

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