Binder

Abstract

To provide a binder that can express high capabilities in both strength and elongation.SOLUTION: A binder contains a polymer having a constitutional unit derived from the general formula (1), and at least one compound selected from the group consisting of a polyfunctional aziridine compound, a polyfunctional oxazoline compound, a polyfunctional epoxy compound and a polyfunctional isocyanate compound. (In the general formula (1), R1 is a C1-4 alkyl group, a hydrogen atom, an alkali metal atom, an alkaline-earth metal atom, or ammonium).SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a binder. [Background technology]

[0002] Conventionally, it has been known that the strength and other functions of fibers can be enhanced by attaching a binder to them, and binders combining polyacrylic acid polymers with inorganic salts have been used (for example, Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-158773 [Patent Document 2] Japanese Patent Application Publication No. 6-184285 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Conventional binders combining polyacrylic acid polymers and inorganic salts have the problem of not being able to achieve sufficiently high fiber strength.

[0005] Therefore, the present invention aims to provide a binder that possesses strength, high elongation, and exhibits high toughness. [Means for solving the problem]

[0006] The inventors have conducted various studies to achieve the above objectives and have arrived at the present invention. Specifically, this disclosure provides a binder comprising a polymer having a structural unit derived from the following general formula (1) and one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds.

[0007] [ka]

[0008] (In general formula (1), R 1 represents an alkyl group having 1 to 4 carbon atoms, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium.)

Advantages of the Invention

[0009] The binder of the present disclosure has high strength and can also exhibit a function that achieves both high elongation. Therefore, it can be applied to various fields such as fibers, fiber processed products, paper, films, and electronic information materials.

Modes for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail. In addition, a combination of two or more of the individual preferred forms of the present invention described below is also a preferred form of the present invention.

[0011] [Binder of the Present Disclosure] <Structural Unit Represented by General Formula (1)> The binder of the present disclosure includes a polymer (hereinafter, also referred to as "the polymer of the present disclosure"). The polymer (hereinafter sometimes referred to as the RHMA-based polymer) includes a structural unit derived from the following general formula (1).

[0012]

Chemical Formula

[0013] (In general formula (1), R 1 represents an alkyl group having 1 to 4 carbon atoms, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium.) The alkyl group having 1 to 4 carbon atoms represented by the above R 1 is preferably an alkyl group having 1 to 2 carbon atoms, and more preferably an alkyl group having 1 carbon atom (methyl group).

[0014] R 1The alkali metal atom represented by is preferably lithium, sodium, or potassium, more preferably sodium or potassium, and even more preferably sodium.

[0015] R 1 Examples of the alkaline earth metal atom represented by include calcium, magnesium, and the like.

[0016] R 1 The ammonium represented by is not limited to NH 4+ and is defined to mean including organic ammonium. Examples of organic ammonium include quaternary ammonium such as tetraalkylammonium like tetramethylammonium and tetrabutylammonium; ammonium formed by protonating an amine (primary to tertiary ammonium), and the like. R 1 Preferably, is ammonium formed by protonating ammonia or an amine. Examples of the amine include trialkylamines such as trimethylamine, triethylamine, and tributylamine (preferably tri-C 1-10 alkylamine); hydroxyalkylamines such as diethanolamine and triethanolamine (preferably di- or tri-(hydroxy-C 1-10 alkyl)amine, etc.), and hydroxyalkylamine is preferred.

[0017] The structural unit represented by the above general formula (1) may be formed by a monomer represented by the following general formula (2) through a polymerization reaction, or may be formed by other methods. For example, in general formula (2), by polymerizing a monomer in which R 1 is an alkyl group having 1 to 4 carbon atoms and then subjecting it to hydrolysis, a structural unit in which R 1 is an alkali metal, an alkaline earth metal, or an ammonium structural unit may be formed in the above general formula (1).

[0018]

Chemical formula

[0019] (In general formula (2), R 1 (This represents an alkyl group with 1 to 4 carbon atoms, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium.) In addition, in the above general formula (2), R 1 It may be one type or two or more types. 1 If there are two or more types, they may be formed by polymerizing two or more monomers represented by the above general formula (2), R 1 The monomer represented by the above general formula (2), in which is an alkyl group having 1 to 4 carbon atoms, may be polymerized, and then the ester group may be partially hydrolyzed or hydrolyzed with two or more basic substances to form it.

[0020] The polymer of this disclosure preferably contains 30% by mass or more of the structural unit represented by the above general formula (1), more preferably 40% by mass or more, even more preferably 45% by mass or more, and even more preferably 50% by mass or more. On the other hand, the polymer of this disclosure preferably contains 99.9% by mass or less of the structural unit represented by the above general formula (1), more preferably 99% by mass or less, even more preferably 97% by mass or less, and most preferably 95% by mass or less. By including it within the above range, the pH and hydrophilicity can be adjusted, and therefore the binder of this disclosure tends to have high strength and high elongation.

[0021] The polymers of this disclosure may have a multilayer structure, for example, a core-shell structure composed of a core portion and a shell portion provided on its surface.

[0022] <Structural units derived from other monomers> The polymers of this disclosure may contain one or more structural units derived from monomers other than the structural unit represented by the general formula (1) above (hereinafter also referred to as "structural units derived from other monomers"). That is, they may contain one or more structural units derived from monomers other than the monomer represented by the general formula (2) above (hereinafter also referred to as "other monomers").

[0023] Structural units derived from other monomers can be formed, for example, by radical polymerization of other monomers. Furthermore, structural units derived from other monomers only need to have the same structure as the structure in which the carbon-carbon double bond of the other monomer is replaced by a carbon-carbon single bond. They are not limited to structural units formed by polymerization of other monomers, but may also be structural units formed by reactions after polymerization.

[0024] Other monomers are not particularly limited, but include (meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate; styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, tert-butylstyrene, chlorostyrene, vinyltoluene; (meth) Carboxyl group-containing monomers such as acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, and maleic anhydride; silane group-containing monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(methoxyethoxy)silane, γ-(meth)acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltrichlorosilane, γ-(meth)acryloyloxypropylhydroxysilane, and γ-(meth)acryloyloxypropylmethylhydroxysilane; 2 Hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; nitrogen atom-containing monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylamide, N-vinylpyrrolidone, and (meth)acrylonitrile; ethylene glycol methoxy (meth)acrylate, Examples include oxo group-containing monomers such as diethylene glycol methoxy(meth)acrylate; fluorine atom-containing monomers such as trifluoroethyl(meth)acrylate, tetrafluoropropyl(meth)acrylate, and octafluoropentyl(meth)acrylate; photostabilized monomers such as 2,2,6,6-tetramethylpiperidine-4-(meth)acrylate; UV-absorbing monomers such as benzotriazole-based UV-absorbing monomers and benzophenone-based UV-absorbing monomers; and polyfunctional ethylenically unsaturated monomers.

[0025] One or more polyfunctional ethylenically unsaturated monomers can be used, and it is preferable that the polyfunctional ethylenically unsaturated monomer is a non-hydrolyzable monomer. Furthermore, as described later, hydrolysis can be carried out by adding a basic aqueous solution such as an aqueous sodium hydroxide solution, an aqueous diethanolamine solution, an aqueous ammonia solution, or an aqueous cyclohexylamine solution to the polymer used in the present invention, so it is more preferable that the non-hydrolyzable monomer has resistance to basic hydrolysis. The non-hydrolyzable monomer is preferably a polyfunctional monomer (hydrocarbon) composed only of carbon atoms and hydrogen atoms, and may optionally have ether bonds. In this specification, a polyfunctional monomer as a hydrocarbon which may have ether bonds is referred to as a hydrocarbon crosslinking agent which may have ether bonds. The hydrocarbon crosslinking agent which may have ether bonds preferably has two or more ethylenically unsaturated bonds, and it is more preferable that it has two ethylenically unsaturated bonds. Examples of hydrocarbon crosslinking agents that may have ether bonds include, specifically, divinylbenzene; 1,3-butadiene; trivinylbenzene; divinylnaphthalene; trivinylcyclohexane; divinyl ether; diallyl ether; and polyvalent methacrylate esters. Preferably, divinylbenzene; 1,3-butadiene; diallyl ether; and polyvalent methacrylate esters are used, and more preferably, divinylbenzene; and polyvalent methacrylate esters.

[0026] Examples of diallyl ethers include dialkylene glycol diallyl ethers such as diethylene glycol diallyl ether, dipropylene glycol diallyl ether, and dibutylene glycol diallyl ether; and polyalkylene glycol diallyl ethers such as polyethylene glycol diallyl ether, polypropylene glycol diallyl ether, and polybutylene glycol diallyl ether. Examples of polyvalent methacrylates include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, and methacrylate-modified polydimethylsiloxane.

[0027] The polymers of this disclosure may contain crosslinkable units such as structural units derived from polyfunctional ethylenically unsaturated monomers. The structural units derived from polyfunctional ethylenically unsaturated monomers are preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and may be 0% by mass (not containing monomer units derived from polyfunctional ethylenically unsaturated monomers) out of 100% by mass of the total monomer units. When crosslinked, the polymer retains its particle shape even after hydrolysis, but if the degree of crosslinking is high, flexibility is lost, adhesion to fibers etc. deteriorates, and the contact area between the binder and the fibers etc. may decrease.

[0028] The polymers of this disclosure may have a particle shape (hereinafter also referred to as "polymer particles of this disclosure"). The preferred particle size of the polymer particles of this disclosure is preferably 10 nm to 10 μm in volume average particle size, more preferably 50 nm to 5 μm, even more preferably 100 nm to 1 μm, and particularly preferably 150 nm to 850 nm. The volume average particle size of the polymers of this disclosure can be measured, for example, by dynamic light scattering. The polymers of this disclosure may have a multilayer structure, and may, for example, be a core-shell structure composed of a core portion and a shell portion provided on its surface.

[0029] The polymer of this disclosure may be a core-shell particle composed of a core portion and a shell portion provided on its surface. If it is a core-shell particle, it is preferable that the shell portion contains a structural unit represented by the general formula (1) above. On the other hand, it is preferable that the core portion contains monomer units derived from a monofunctional (meth)acrylic monomer. As the monofunctional (meth)acrylic monomer, alkyl esters of (meth)acrylic acid having 1 to 12 carbon atoms are preferred, and alkyl esters of (meth)acrylic acid having 1 to 4 carbon atoms are more preferred. Examples of monofunctional (meth)acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc., and one or more of these can be used. The core portion preferably contains 50% by mass or more monomer units derived from monofunctional (meth)acrylic monomers, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass. The core portion may or may not contain structural units represented by the above general formula (1) and structural units derived from polyfunctional ethylenically unsaturated monomers.

[0030] The core portion may contain monomers other than monofunctional (meth)acrylic monomers. Examples of monomers other than monofunctional (meth)acrylic monomers include monofunctional styrene monomers. Examples of styrene monomers include alkylstyrenes such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, ethyl vinylbenzene, and pt-butylstyrene; and styrene monofunctional monomers such as halogen-containing styrenes such as o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene. These monomers may be used individually or in combination of two or more.

[0031] <Polyfunctional aziridine compounds> This refers to a compound having one or more oxazoline groups in one molecule, and further having one or more reactive functional groups in addition to the said functional group. Examples of reactive functional groups include carboxyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, aromatic hydroxyl groups, thiol groups, aromatic thiol groups, aziridine groups, oxazoline groups, epoxy groups, isocyanate groups, and carbodiimide groups.

[0032] Examples of polyfunctional aziridine compounds include N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxite), N,N'-toluene-2,4-bis(1-aziridine carboxite), bisisophthaloyl-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, N,N'-hexamethylene-1,6-bis(1-aziridine carboxite), trimethylolpropane-tri-β-aziridinyl propionate, tetramethylolmethane-tri-β-aziridinyl propionate, tris-2,4,6-(1-aziridinyl)-1,3,5-triazine, trimethylolpropane tris[3-(1-aziridinyl)propionate], and trimethylolpropane tris[3-(1 Examples include aziridinyl butyrate, trimethylolpropanetris[3-(1-(2-methyl)aziridinyl)propionate], trimethylolpropanetris[3-(1-aziridinyl)-2-methylpropionate], 2,2'-bishydroxymethylbutanoltris[3-(1-aziridinyl)propionate], pentaerythritol tetra[3-(1-aziridinyl)propionate], diphenylmethane-4,4-bis-N,N'-ethyleneurea, 1,6-hexamethylenebis-N,N'-ethyleneurea, 2,4,6-(triethyleneimino)-Syn-triazine, bis[1-(2-ethyl)aziridinyl]benzene-1,3-carboxylic acid amide, and aziridine group-containing polymers.

[0033] <Polyfunctional oxazoline compounds> This refers to a compound having one or more oxazoline groups in one molecule, and further having one or more reactive functional groups in addition to the said functional group. Examples of reactive functional groups include carboxyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, aromatic hydroxyl groups, thiol groups, aromatic thiol groups, aziridine groups, oxazoline groups, epoxy groups, isocyanate groups, and carbodiimide groups.

[0034] Examples of polyfunctional oxazoline compounds include 2'-methylenebis(2-oxazoline), 2,2'-ethylenebis(2-oxazoline), 2,2'-ethylenebis(4-methyl-2-oxazoline), 2,2'-propylenebis(2-oxazoline), 2,2'-tetramethylenebis(2-oxazoline), 2,2'-hexamethylenebis(2-oxazoline), 2,2'-octamethylenebis(2-oxazoline), 2,2'-p-phenylenebis(2-oxazoline), 2,2'-p-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylenebis(4-methyl-2-oxazoline), and 2,2'-p-phenylenebis(4-phenyl-2- Examples include oxazoline, 2,2'-m-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxazoline), 2,2'-m-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-m-phenylenebis(4-phenylenebis-2-oxazoline), 2,2'-o-phenylenebis(2-oxazoline), 2,2'-o-phenylenebis(4-methyl-2-oxazoline), 2,2'-bis(2-oxazoline), 2,2'-bis(4-methyl-2-oxazoline), 2,2'-bis(4-ethyl-2-oxazoline), 2,2'-bis(4-phenyl-2-oxazoline), and oxazoline group-containing polymers.

[0035] <Polyfunctional epoxy compounds> This refers to a compound having one or more epoxy groups in one molecule, and further having one or more reactive functional groups in addition to the said functional group. Examples of reactive functional groups include carboxyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, aromatic hydroxyl groups, thiol groups, aromatic thiol groups, aziridine groups, oxazoline groups, epoxy groups, isocyanate groups, and carbodiimide groups.

[0036] Examples of polyfunctional epoxy compounds include aromatic epoxy compounds, aliphatic epoxy compounds, alicyclic epoxy compounds, and hydrogenated epoxy compounds. Preferably, they are alicyclic epoxy compounds and aliphatic epoxy compounds, and more preferably, alicyclic glycidyl ether compounds and aliphatic glycidyl ether compounds.

[0037] Examples of alicyclic glycidyl ether compounds include dicyclopentadiene dimethanol diglycidyl ether, adamantane dimethanol diglycidyl ether, 1,2-bis(glycidyloxy)cyclohexane, 1,3-bis(glycidyloxy)cyclohexane, 1,4-bis(glycidyloxy)cyclohexane, 1,4-bis(glycidyloxy)decalin, 1,6-bis(glycidyloxy)decalin, 1,4-bis(glycidyloxymethyl)cyclohexane, 1,4-bis(glycidyloxybutyl)cyclohexane, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 1,4-cyclohexanedicarboxylic acid diglycidyl ester, and 1,3,5-cyclohexanetricarboxylic acid triglycidyl ester.

[0038] Examples of aliphatic glycidyl ether compounds include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol, diglycidyl ether of 1,4-butanediol, diglycidyl ether of cyclohexanedimethanol, di or triglycidyl ether of glycerin, di or triglycidyl ether of trimethylolpropane, tetraglycidyl ether of pentaerythritol, and diglycidyl ether of dodecahydrobisphenol A.

[0039] Commercially available products include, for example, sorbitol polyglycidyl ether (e.g., "Denacol EX-612", "Denacol EX-614", "Denacol EX-622", manufactured by Nagase ChemteX Co., Ltd.), glycerol polyglycidyl ether (e.g., "Denacol EX-314", manufactured by Nagase ChemteX Co., Ltd.), diglycerol polyglycidyl ether (e.g., "Denacol EX-421", manufactured by Nagase ChemteX Co., Ltd.), and polyglycerol polyglycidyl Diglycidyl ether (e.g., "Denacol EX-521", manufactured by Nagase ChemteX Corporation), pentaerythritol polyglycidyl ether (e.g., "Denacol EX-411", manufactured by Nagase ChemteX Corporation), trimethylolpropane polyglycidyl ether (e.g., "Denacol EX-321", manufactured by Nagase ChemteX Corporation), neopentyl glycol diglycidyl ether (e.g., "Denacol EX-211", manufactured by Nagase ChemteX Corporation), 1,6 -Hexanediol diglycidyl ether (e.g., "Denacol EX-212", manufactured by Nagase ChemteX Corporation), ethylene glycol diglycidyl ether (e.g., "Denacol EX-811", manufactured by Nagase ChemteX Corporation), diethylene glycol diglycidyl ether (e.g., "Denacol EX-851", manufactured by Nagase ChemteX Corporation), polyethylene glycol diglycidyl ether (e.g., "Denacol EX-821", "Denacol EX Examples include "-830", "Denacol EX-832", "Denacol EX-841", "Denacol EX-861" (manufactured by Nagase ChemteX Corporation), propylene glycol diglycidyl ether (e.g., "Denacol EX-911" (manufactured by Nagase ChemteX Corporation)), polypropylene glycol diglycidyl ether (e.g., "Denacol EX-941", "Denacol EX-920", "Denacol EX-931" (manufactured by Nagase ChemteX Corporation)), etc.

[0040] <Polyfunctional isocyanate compounds> This refers to a compound having one or more isocyanate groups in one molecule, and further having one or more reactive functional groups in addition to the said functional group. Examples of reactive functional groups include carboxyl groups, (meth)acryloyl groups, amino groups, hydroxyl groups, aromatic hydroxyl groups, thiol groups, aromatic thiol groups, aziridine groups, oxazoline groups, epoxy groups, isocyanate groups, and carbodiimide groups.

[0041] Examples of polyfunctional isocyanate compounds include diisocyanate compounds such as aromatic diisocyanate compounds, alicyclic diisocyanate compounds, and aliphatic diisocyanate compounds; adduct polyisocyanate compounds; burette polyisocyanate compounds; and polyisocyanate compounds having an isocyanurate ring. Preferably, aromatic diisocyanate compounds, alicyclic diisocyanate compounds, and aliphatic diisocyanate compounds are used.

[0042] Examples of aromatic diisocyanate compounds include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4,4′-dibenzyle diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate.

[0043] Examples of alicyclic diisocyanate compounds include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-cyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanate methyl)cyclohexane.

[0044] Examples of aliphatic diisocyanate compounds include tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,4-butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate.

[0045] As for polyfunctional isocyanate compounds, so-called blocked isocyanates are preferred from the viewpoint of stability, in which the isocyanate group is inactivated by reacting it with a masking agent having active hydrogen. For example, commercially available products include DM-6400, Meikanate DM-3031CONC, Meikanate DM-35HC, Meikanate TP-10, Meikanate CX, SU-268A, NBP-8730, NBP-211 [manufactured by Meisei Chemical Industry Co., Ltd.], Elastron BN-69, BN-77, BN-27, BN-11, BN-44, BN-04, BN-08, E-37, H-3-DF, H-15, BAP, NEW BAP, F-29, W-11P, MF-25K [manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], Takenate WB-700, WB-770, WB-920 [manufactured by Mitsui Chemicals Polyurethane Co., Ltd.], Karens MOI-BM, MOI-BP [manufactured by Showa Denko K.K.], Duranate MF-K60B, SBN-70D, MF-B60B, MF-B90B, 17B-60P, TPA-B80B, TPA-B80E, E402-B80B [manufactured by Asahi Kasei Chemicals Corporation], BI-7950, BI-7951, BI-7960, BI-7961, BI-7963, BI-7982, BI-7991, BI-7992 [Ba Examples include Xenden Co., Ltd.'s IPDI-B1065, IPDI-B1530, IPDI-BF1540 [HULS Co., Ltd.], Barnock B7-887-60, B3-867, DB980K [Dainippon Ink, Inc.], Desmodule BL1100 / 1, Sumijoule BL3175, Desmodule BL3272MPA, Desmodule BL3475BA / SN, Desmodule BL3575 / 1MPA / SN [Sumitomo Bayer Urethane Co., Ltd.], and 3-(3,4-dichlorophenyl)-1,1-dimethylurea "DCMU" [Hodogaya Chemical Co., Ltd.].

[0046] The polymers of this disclosure may contain, in addition to the structural unit represented by the general formula (1) above, one or more structural units derived from one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds (hereinafter also referred to as "structural units derived from polyfunctional compounds").

[0047] The polymers of this disclosure preferably contain 1% by mass or more of structural units derived from one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds, more preferably 5% or more, and even more preferably 10% by mass or more. On the other hand, the polymers of this disclosure preferably contain 50% by mass or less of structural units derived from one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Containing these components within the above ranges tends to result in high strength and high elongation.

[0048] The binder of this disclosure preferably contains 0.5% by mass or more of structural units derived from one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds, more preferably 5% by mass or more, and even more preferably 10% by mass or more. On the other hand, the polymer of this disclosure preferably contains 50% by mass or less of structural units derived from one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds, more preferably 40% by mass or less, and even more preferably 30% by mass or less. Including these components within the above range tends to result in high toughness.

[0049] [Method for producing the binder of this disclosure] <Polymerization method> RHMA polymers are obtained by polymerizing at least one monomer represented by formula (2) above, in which R1 is an alkyl group having 1 to 4 carbon atoms (hereinafter referred to as hydroxymethyl acrylic acid ester), in an aqueous solvent, and, if necessary, partially or completely hydrolyzing it to convert part or all of the portion corresponding to R1 into hydrogen atoms, alkali metal atoms, alkaline earth metal atoms, ammonium, etc. Hydroxymethyl acrylic acid ester may also be polymerized with other monomers (hereinafter these may be collectively referred to as "raw material monomer components"). When hydroxymethyl acrylic acid ester is used as a raw material monomer, the product can be made into particulate matter even when polymerized in an aqueous solvent.

[0050] Polymerization methods include suspension polymerization, emulsion polymerization, and dispersion polymerization. Among these, emulsion polymerization is preferred, in which the above-mentioned monomer components are dispersed in a reaction solvent in the presence of an emulsifier and a (radical) polymerization reaction is carried out. Specifically, the polymer production method of the present invention preferably includes emulsion polymerization, in which at least one monomer represented by formula (2) is dispersed in an aqueous solvent in the presence of an emulsifier and a polymerization reaction is carried out. Emulsion polymerization may be carried out in one step or in multiple steps.

[0051] The emulsifier can be one or more types, and may be a non-reactive surfactant or a reactive surfactant having a radically polymerizable group in its structure.

[0052] Non-reactive surfactants include anionic and nonionic surfactants. Examples of anionic surfactants include fatty acid salts, alkyl (allyl) sulfonates, alkyl sulfate esters, and polyoxyethylene alkyl (phenyl) ether sulfates, while examples of nonionic surfactants include polyoxyethylene alkyl (phenyl) ethers, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, and polyoxyethylene polyoxypropylene block polymers.

[0053] Reactive surfactants include both anionic and nonionic surfactants. Examples of anionic reactive surfactants include, but are not limited to, ether sulfate-type reactive surfactants and phosphate ester-type reactive surfactants.

[0054] The amount of emulsifier is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and particularly preferably 3 parts by mass or less, based on 100 parts by mass of the total amount of raw material monomer components.

[0055] In this disclosure, an aqueous solvent refers to water alone or a mixed solvent of water and a water-miscible organic solvent, but water alone is preferred. Typically, an aqueous solvent refers to a solvent in which the water content exceeds 50% by volume. As water, ion-exchanged water (deionized water), distilled water, pure water, etc., can be used. As the water-miscible organic solvent, an organic solvent that can be uniformly mixed with water (such as a lower alcohol) can be used. From the viewpoint of minimizing the residual organic solvent in the polymer, an aqueous solvent in which 80% or more by volume is water is preferred, an aqueous solvent in which 90% or more by volume is water is more preferred, an aqueous solvent in which 95% or more by volume is water is even more preferred, an aqueous solvent consisting substantially of water (an aqueous solvent in which 99.5% or more by volume is water) is particularly preferred, and water alone is most preferred.

[0056] When polymerizing the raw material monomer components, methods such as polymerization initiators, irradiation with ultraviolet light or other radiation, and application of heat are used. It is preferable to use polymerization initiators, and from the viewpoint of efficiently reacting the raw material monomer components and sufficiently reducing the amount of residual monomers, polymerization initiators that combine oxidizing agents and reducing agents (redox-type polymerization initiators) are preferred.

[0057] The polymers of this disclosure can be hydrolyzed by adding, for example, a basic aqueous solution such as an aqueous solution of sodium hydroxide, an aqueous solution of calcium hydroxide, an aqueous solution of ammonia, or an aqueous solution of cyclohexylamine. Furthermore, partial or complete neutralization can be performed by adding an acid as appropriate to the hydrolysis solution. By performing hydrolysis and neutralization, the group corresponding to R1 in the above general formula (1) can be changed to a hydrogen atom, an alkali metal atom, an alkali metal atom, or ammonium. By adjusting the amount of acid or base used during polymerization, hydrolysis, and neutralization, or by adjusting the proportion of monomer units in which R1 is a hydrogen atom, the pH and hydrophilicity of the polymer can be adjusted, which tends to improve the handling properties as a binder and facilitate uniform dispersion on the binder.

[0058] <Water dispersion> The present invention also includes binders in which the polymer is dispersed in water (aqueous dispersion), by which the polymer is dispersed in water as described above. The aqueous dispersion has excellent hydrophilicity because the polymer has a hydroxymethyl group. It also has good dispersibility in water, high storage stability as a dispersion, and can be easily hydrolyzed. When hydrolysis and subsequent neutralization as necessary are performed, hydrolysis can be carried out by adding a basic aqueous solution such as an aqueous sodium hydroxide solution, an aqueous ammonia solution, an aqueous diethanolamine solution, or an aqueous cyclohexylamine solution to the polymer contained in the aqueous dispersion. Furthermore, partial or complete neutralization can be performed by adding an acid as appropriate to the hydrolysis solution. By performing hydrolysis and neutralization, the group corresponding to R1 in the above general formula (1) can be changed to a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium. The volume-average particle size of the polymer can be easily adjusted by adjusting the amount of acid or base used during polymerization, hydrolysis, and neutralization, or by adjusting the proportion of monomer units in which R1 is a hydrogen atom, so the binder can be used in a wide range of applications.

[0059] The aqueous dispersion preferably contains 5% by mass or more of the polymer, more preferably 10% by mass or more, preferably 100% by mass or less, and more preferably 50% by mass or less.

[0060] The volume-average particle size of the polymer contained in the aqueous dispersion is preferably 10 nm to 10 μm, more preferably 50 nm to 5 μm, even more preferably 100 nm to 1 μm, and particularly preferably 150 nm to 850 nm. The volume-average particle size of the polymer contained in the aqueous dispersion was measured by dynamic light scattering.

[0061] [Uses of the binders in this disclosure] The applications of the binder used in this invention are not limited. Due to its ability to achieve both tensile strength and elongation, it can be applied to various fields such as fibers, textile products, nonwoven fabrics, sheets, paper, binders, paints, adhesives, thickeners, thermoplastic resins, thermosetting resins, various films, electronic information materials, catalyst supports, thermal insulation materials, and low-reflectance materials. [Examples]

[0062] [Synthesis of polymers] <Manufacturing Example 1> In a stainless steel reaction vessel equipped with a stirrer, thermometer, and condenser, 804.8 parts by mass of deionized water and 0.72 parts by mass of Adekarya Soap SR-20 (100% by mass of active ingredient, manufactured by ADEKA), an anionic reactive surfactant mainly composed of ether sulfate-type ammonium salt, diluted to 25.0% by mass of active ingredient with ion-exchanged water (hereinafter referred to as "SR-20 (25.0% by mass of active ingredient)") were added, and the internal temperature was raised to 75°C and maintained at that temperature. In a dropping funnel A, 67.5 parts by mass of methyl methacrylate (hereinafter referred to as "MMA"), 67.5 parts by mass of n-butyl acrylate (hereinafter referred to as "BA"), 11.0 parts by mass of SR-20 (25.0% by mass of active ingredient), and 124.0 parts by mass of deionized water were added to prepare a dropping pre-emulsion A in the dropping funnel. Pre-emulsion B for dropping was prepared in dropping funnel B by adding 135.0 parts by mass of methyl 2-hydroxymethylacrylate (hereinafter referred to as "RHMA"), 15.0 parts by mass of divinylbenzene (manufactured by Nippon Steel Chemical & Material Co., Ltd., divinylbenzene purity 81%, hereinafter referred to as "DVB810"), 12.3 parts by mass of SR-20 (active ingredient 25.0% by mass), 0.27 parts by mass of aqueous ammonia solution (concentration 28% by mass), and 137.5 parts by mass of deionized water. 320 parts by mass of hydrogen peroxide solution (concentration 0.61% by mass) was added to dropping funnel C. 320 parts by mass of aqueous L-ascorbic acid solution (concentration 0.92% by mass) was added to dropping funnel D.

[0063] Next, after purging the reaction vessel with nitrogen gas, 15.0 parts by mass of a mixed monomer composition of 7.5 parts by mass of MMA and 7.5 parts by mass of BA, 20 parts by mass of hydrogen peroxide solution (concentration 0.25% by mass), and 20 parts by mass of L-ascorbic acid aqueous solution (concentration 0.38% by mass) were added to the reaction vessel to carry out the initial polymerization reaction. Subsequently, dropwise pre-emulsion A was added dropwise from dropwise funnel A for 60 minutes, dropwise pre-emulsion B from dropwise funnel B for 180 minutes, hydrogen peroxide solution from dropwise funnel C for 240 minutes, and L-ascorbic acid aqueous solution from dropwise funnel D for 240 minutes. Note that the dropwise addition of dropwise pre-emulsion B was started immediately after the dropwise addition of dropwise pre-emulsion A was completed.

[0064] After the dropwise addition was complete, the internal temperature of the reaction vessel was maintained at 75°C and allowed to mature for 2 hours. Then, the reaction solution was cooled to obtain a polymer particle dispersion in which polymer particles were dispersed. 280.0 parts by mass of the polymer particle aqueous dispersion obtained above and 23.6 parts by mass of a sodium hydroxide aqueous solution (concentration 20.0% by mass) as a basic aqueous solution were mixed and stirred overnight at 25°C to obtain a polymer particle aqueous dispersion (1a) in which partially hydrolyzed polymer particles (1) were dispersed. At this time, the ratio of the number of moles of added sodium hydroxide to the number of moles of RHMA in the polymer particle aqueous dispersion was 75%. The volume-average particle diameter was 339 nm.

[0065] <Manufacturing Example 2> Polymer particles (2) and a polymer particle aqueous dispersion (2a) in which polymer particles (2) are dispersed were obtained in the same manner as in Production Example 1, except that the basic aqueous solution used during hydrolysis was changed to an aqueous ammonia solution (concentration 25.0% by mass) of 8.0 parts by mass. In this case, the ratio of the number of moles of ammonia added to the number of moles of RHMA in the polymer particle aqueous dispersion was 75%. The volume-average particle diameter was 391 nm.

[0066] <Manufacturing Example 3> In a stainless steel reaction vessel equipped with a stirrer, thermometer, and condenser, 836.8 parts by mass of deionized water and 3.84 parts by mass of SR-20 (active ingredient 25.0% by mass) were added, and the internal temperature was raised to 75°C and maintained at that temperature. 80.0 parts by mass of RHMA, 48.0 parts by mass of BA, and 32.0 parts by mass of 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate (manufactured by Showa Denko, Karenz MOI-BM, hereinafter referred to as "MOI-BM") were added to dropping funnel A to prepare a mixed monomer composition for dropping in the dropping funnel. 100 parts by mass of hydrogen peroxide solution (concentration 1.07% by mass) was added to dropping funnel B. 100 parts by mass of L-ascorbic acid aqueous solution (concentration 1.60% by mass) was added to dropping funnel C. An emulsifier aqueous solution was prepared in a dropping funnel D by adding 12.2 parts by mass of SR-20 (active ingredient 25.0% by mass), 0.36 parts by mass of ammonia aqueous solution (concentration 28% by mass), and 87.4 parts by mass of deionized water. Next, after purging the reaction vessel with nitrogen gas, 40.0 parts by mass of a mixed monomer composition containing 20.0 parts by mass of RHMA, 12.0 parts by mass of BA, and 8.0 parts by mass of MOI-BM, 20 parts by mass of hydrogen peroxide solution (concentration 1.34% by mass), and 20 parts by mass of L-ascorbic acid aqueous solution (concentration 2.00% by mass) were added to the reaction vessel to carry out the initial polymerization reaction. Subsequently, the mixed monomer for dropping was added dropwise from dropping funnel A for 240 minutes, hydrogen peroxide solution from dropping funnel B for 240 minutes, L-ascorbic acid aqueous solution from dropping funnel C for 240 minutes, and emulsifier aqueous solution from dropping funnel D for 240 minutes. After the dropwise addition was complete, the internal temperature of the reaction vessel was maintained at 75°C and allowed to mature for 2 hours. Then, the reaction solution was cooled to obtain a polymer particle dispersion in which polymer particles were dispersed. 280.0 parts by mass of the polymer particle aqueous dispersion obtained above and 26.2 parts by mass of a sodium hydroxide aqueous solution (concentration 20.0% by mass) as a basic aqueous solution were mixed and stirred overnight at 25°C to obtain a polymer particle aqueous dispersion (3a) in which a mixture (3) of partially hydrolyzed polymer particles and partially hydrolyzed and water-soluble polymer was dispersed. At this time, the ratio of the number of moles of added sodium hydroxide to the number of moles of RHMA in the polymer particle aqueous dispersion was 75%. The volume-average particle diameter was 665 nm.

[0067] <Manufacturing Example 4> Except for changing the basic aqueous solution used during hydrolysis in Production Example 3 to an aqueous ammonia solution (concentration 25.0% by mass) of 8.9 parts by mass, a mixture (4) of partially hydrolyzed polymer particles and partially hydrolyzed, water-soluble polymer, and an aqueous dispersion of polymer particles (4a) in which the mixture (4) was dispersed were obtained in the same manner as in Production Example 3. In this case, the ratio of the number of moles of ammonia added to the number of moles of RHMA in the aqueous dispersion of polymer particles was 75%. The volume-average particle diameter was 130 nm.

[0068] <Manufacturing Example 5> Polyacrylic acid (average molecular weight approximately 5,000) manufactured by Fujifilm Wako Pure Chemical Industries was dissolved in deionized water to a concentration of 5% by mass. To the resulting aqueous polyacrylic acid solution, a 10% by mass sodium hydroxide aqueous solution was added so that the sodium hydroxide content was 25 mol% relative to the carboxyl groups of the polyacrylic acid. The solution was stirred overnight at 25°C to obtain a partially neutralized aqueous polyacrylic acid solution.

[0069] <Manufacturing Example 6> 200.3 g of deionized water was charged into a 0.5 liter glass separable flask equipped with a reflux condenser, stirrer, and thermometer (initial charge), and the mixture was heated to its boiling point while stirring. Then, while stirring, 118.9 g (1.32 mol) of 80% acrylic acid (hereinafter referred to as "80% AA") was added for 180 minutes, 102.1 g (0.88 mol) of 2-hydroxyethyl acrylate (hereinafter referred to as "HEA") for 180 minutes, 34.1 g of 5% sodium persulfate (hereinafter referred to as "NaPS") for 195 minutes, and 13.0 g of 15% sodium hypophosphate (hereinafter referred to as "SHP") for 18 minutes, followed by 52.0 g for 162 minutes, each added dropwise through separate supply channels via a tip nozzle at two different supply rates. Each component was added dropwise continuously at a constant rate, except for the 15% SHP. After the addition of 80% AA was complete, the reaction solution was held under reflux at its boiling point for an additional 30 minutes (maturation). The resulting aqueous polymer solution had a solid content of 40.9% and a weight-average molecular weight (Mw) of 4900. 280.0 parts by mass of the acrylic acid copolymer aqueous solution obtained above and 47.7 parts by mass of a sodium hydroxide aqueous solution (concentration 20% by mass) as a basic aqueous solution were mixed and stirred overnight at 25°C to obtain a partially neutralized polyacrylic acid copolymer (X). At this time, the ratio of the number of moles of sodium hydroxide added to the number of moles of acrylic acid in the acrylic acid copolymer aqueous solution was 25%.

[0070] <Volume-average particle size> The particulate dispersion was diluted with deionized water, and its volume-average particle size (nm) was determined by dynamic light scattering using a light scattering particle size distribution analyzer (Spectris "Zetasizer Ultra"). <Weight average molecular weight> The weight-average molecular weight (Mw) was measured under the following conditions. Equipment: Tosoh HLC-8320GPC Detector: RI Column: Tosoh TSK-GEL G3000PWXL Column temperature: 35℃ Flow rate: 0.5ml / min Calibration curve: POLY SODIUM ACRYLATE STANDARD, manufactured by Sowa Kagaku Co., Ltd. Eluent: A solution obtained by diluting a mixture of sodium dihydrogen phosphate dodecahydrate and disodium hydrogen phosphate dihydrate (34.5g / 46.2g) with pure water to 5000g.

[0071] <Tensile strength> A tensile testing machine (Shimadzu Corporation's "AUTOGRAPH AG-1kNXPlus") was used to clamp the test specimen in the grips so that the test length was 180 mm, and the tensile test was performed at a speed of 20 mm / min.

[0072] The tensile strength was determined from the maximum test force at the time of fracture of the test specimen, according to the following formula. TIFF2022149647000004.tif5150

[0073] The elongation rate was determined from the displacement at the time of fracture of the test specimen according to the following formula. TIFF2022149647000005.tif5150

[0074] <Reference example 1> A sheet of traditional Japanese paper (Maruai Co., Ltd., Yukinoko paper, 50 μm film thickness) was cut to a width of 15 mm and a length of 250 mm to prepare test specimen 0. The tensile strength described above was measured for test specimen 0. The measurement results are shown in Table 1. <Example 1> The polymer particle dispersion (1a) obtained in Production Example 1 was diluted with deionized water to a polymer particle concentration of 1% by mass. Next, the aqueous polyisocyanate crosslinking agent Elastron BN-69 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a concentration of 20% by mass relative to the polymer particles and thoroughly stirred. The resulting liquid was spread onto a tray, and a sheet of Japanese paper (Maruai Co., Ltd., Yukinoko Japanese paper, 50 μm film thickness) sandwiched between a stainless steel mesh guide with a mesh opening of 500 μm was gently immersed in it. After immersion for 1 minute, the filter paper was lifted out together with the stainless steel mesh guide, and the liquid was drained until no more diluted liquid dripped out. The stainless steel mesh guide was dried in a forced-air constant-temperature incubator (Yamato Kagaku Co., Ltd., "DNF400") at 150°C for 15 minutes. After that, the stainless steel mesh guide was removed, and the filter paper was cut to a width of 15 mm and a length of 250 mm to prepare test piece 1. The tensile test described above was performed on test specimen 1. Furthermore, the effects of applying the binder on strength improvement and elongation improvement were calculated based on the following formula. The calculation results are shown in Table 1. TIFF2022149647000006.tif12150

[0075] <Examples 2-9, Comparative Examples 1-9> Except for using the fine particle dispersions (1a) obtained in Production Example 1, the fine particle dispersions from Production Examples 2-4, the aqueous solutions of the water-soluble polymers from Production Examples 5-6, the water-based polyisocyanate crosslinking agent Elastron BN-69 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the special epoxy compound Denacol EX-614B (manufactured by Nagase ChemteX Corporation) were used instead, and the tensile strength and elongation were measured in the same manner as in Example 1. The measurement results are shown in Table 1. The strength improvement effect and elongation improvement effect were also calculated in the same manner as in Example 1, and the calculation results are shown in Table 1.

[0076] [Table 1]

[0077] The results in Table 1 clearly show that the binder of this disclosure exhibits functionality that achieves both high strength and elongation.

Claims

1. A binder comprising a polymer having a structural unit derived from the following general formula (1) and one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds, and polyfunctional isocyanate compounds: 【Chemistry 1】 (In general formula (1), R １ represents an alkyl group having 1 to 4 carbon atoms, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium.

2. A polymer for a binder, comprising a polymer having a structural unit derived from the following general formula (1), and a structural unit derived from one or more compounds selected from the group consisting of a polyfunctional aziridine compound, a polyfunctional oxazoline compound, a polyfunctional epoxy compound, and a polyfunctional isocyanate compound: 【Chemistry 2】 (In general formula (1), R １ represents an alkyl group having 1 to 4 carbon atoms, a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, or ammonium.

3. A binder comprising the polymer for binder according to claim 2 and one or more compounds selected from the group consisting of polyfunctional aziridine compounds, polyfunctional oxazoline compounds, polyfunctional epoxy compounds and polyfunctional isocyanate compounds.

4. The binder according to any one of claims 1 to 3, wherein the polyfunctional epoxy compound is a polyfunctional glycidyl ether compound.

5. The binder according to any one of claims 1 to 3, wherein the polyfunctional isocyanate compound is a blocked isocyanate compound.