JP2005060586A - Aqueous emulsion of (met)acrylic complex urethane-based resin composition and method for producing the same, and coating agent using the same emulsion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare an aqueous emulsion of a (meth)acryl complex urethane-based resin composition free from problem of volatilization of an organic solvent, a tertiary amine, or the like and scarcely substantially containing a harmful volatile component. <P>SOLUTION: The aqueous emulsion of the (meth)acryl complex urethane-based resin composition comprises a urethane resin part having an acidic functional group neutralized with an inorganic salt in a same micelle and a (meth)acryl complex urethane-based resin part. The method for producing the aqueous emulsion comprises neutralizing an acidic functional group in a urethane prepolymer with a basic/radically polymerizable compound having at least one basic functional group and at least one radically polymerizable functional group in the molecule, emulsifying the neutralized prepolymer and then carrying out chain extension, salt exchange of an alkali metal with a hydroxide and polymerization of (meth)acrylic monomer. Since the basic/radically polymerizable compound isolated by salt exchange is copolymerized in and incorporated into a (meth)acryl resin during the polymerization, the compound is free from problem of volatilization. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an aqueous emulsion of a (meth) acrylic composite urethane-based resin composition containing a urethane resin portion and a (meth) acrylic resin portion in the same micelle, a method for producing the same, and the (meth) acrylic composite urethane-based resin composition The present invention relates to a coating agent using a water-based emulsion. Specifically, it exhibits excellent adhesion and solvent resistance when used in applications such as plastics, paper, metal, wood, fiber, and other paints, adhesives, and substantially organic solvents and tertiary amines. A (meth) acrylic composite urethane-based resin composition aqueous emulsion that does not contain volatile organic compounds and has no problems such as odor and toxicity, and a method for producing the same, and this (meth) acrylic composite urethane-based resin composition aqueous emulsion It relates to the coating material used.

  Conventionally, solvent-based resins have been used as surface coating agents for base materials from the standpoint of stain resistance and water resistance, but in recent years, organic solvents have been contained in coating films due to problems such as air pollution and chemical sensitivity. A coating agent that does not remain on the surface is desired.

  An aqueous emulsion is used as a coating agent containing no organic solvent. However, since the conventional aqueous emulsion uses a surfactant, there is a problem that it is poor in stain resistance and water resistance. In particular, in the case of an aqueous urethane emulsion, since an organic solvent is often used in the production process, the problem caused by the organic solvent is not solved.

  Therefore, as an aqueous urethane emulsion that does not use an organic solvent, after reacting a diisocyanate compound, a compound containing an ion-forming group and a hydroxyl group and a polyol in an acrylic monomer, the ion-forming group is neutralized and emulsified, and then acrylic. It has been reported that an acrylic composite urethane resin aqueous emulsion containing a urethane resin portion substantially free of a solvent and an acrylic resin portion is obtained by polymerization. In this case, when an acidic functional group such as a carboxylic acid is used as the emulsifying group, the emulsification is not performed unless the acid is neutralized. Examples of the neutralizing agent include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and tertiary amines such as ammonia, triethylamine, and alkanolamine. Among these, alkali metal hydroxides are used. Use is not appropriate for the following reasons. That is, when an isocyanate group-terminated prepolymer synthesized in an acrylic monomer is neutralized with an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, these are solid and the urethane prepolymer acrylic monomer. Since it does not dissolve in the solution, it must be added as an aqueous solution of sodium hydroxide or potassium hydroxide. However, because the aqueous solution has basicity, it acts catalytically on the isocyanate group, and when added to the isocyanate-terminated prepolymer, the isocyanate group causes a trimerization reaction or the reaction between the isocyanate group and water. To increase the molecular weight during emulsification. For this reason, it becomes difficult to obtain an aqueous emulsion by gelation during emulsification.

  On the other hand, as a method using an inorganic salt as an emulsifying group, a method in which a compound in which an inorganic salt obtained by neutralizing an acidic functional group with an alkali metal in advance is added during prepolymerization reaction or neutralization may be considered. The compound having a very high hydrophilicity is difficult to introduce due to its extremely low solubility in organic solvents with low hydrophilicity and organic compounds with high hydrophobicity such as diisocyanate compounds and polyols.

  For these reasons, it is generally known that a tertiary amine such as ammonia or triethylamine is used as a neutralizing agent (Patent Document 1). However, among these tertiary amines, when a tertiary amine that does not contain a hydroxyl group, such as ammonia or triethylamine, is used, a part of the amine is volatilized during drying. May not be recovered and may leak to the outside, and odor and toxicity are regarded as problems. Furthermore, some of the amine remains in the coating film, resulting in an amine odor from the finished product, or dissipated into the atmosphere over time, eliminating the tertiary amine odor and toxicity completely. There is no problem.

As a technique for preventing volatilization of the neutralizing agent, it is known to use alkanolamines containing a hydroxyl group as the neutralizing agent. That is, when an alkanolamine is used in combination with a water-dispersed curing agent, the alkanolamine is immobilized in the coating film by the reaction of an isocyanate group and a hydroxyl group, and thus dissipation is prevented. However, even in this case, the reaction cannot be completely completed depending on the mixing ratio of the water-dispersed curing agent, so that unreacted alkanolamine may remain. Not reached.
USP 4,644,030

  An object of the present invention is to provide an aqueous emulsion of a (meth) acrylic composite urethane resin composition that is free from the problem of volatilization of organic solvents, tertiary amines, and the like and substantially contains no harmful volatile components.

  The (meth) acrylic composite urethane resin composition aqueous emulsion of the present invention contains a urethane resin part having an acidic functional group neutralized with an inorganic salt and a (meth) acrylic resin part in the same micelle. Features.

  In the present invention, the (meth) acrylic resin portion is a polymer of a (meth) acrylic monomer and a compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule. Preferably there is. The acidic functional group is preferably a carboxyl group, and the counter ion is preferably sodium and / or potassium. The compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule is preferably dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate.

The method for producing an aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention is a method for producing such an aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention. ) To (6).
(1) In a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule, a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and two hydroxyl groups and one in the molecule The 1st process which makes the compound which has the above acidic functional group react, and prepolymerizes.
(2) A compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule, wherein the acidic functional group in the urethane prepolymer obtained in the first step is neutralized. 2 steps.
(3) A third step of adding water to emulsify.
(4) Fourth step of chain extension using a chain extender.
(5) A fifth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(6) A sixth step of polymerizing the (meth) acrylic monomer.
(However, when water is used as the chain extender, the fourth step does not need to be an independent step, and in the sixth step, a chain extension reaction can be performed during the polymerization of the (meth) acrylic monomer. That is, when water is used as the chain extender, the chain extension reaction can be carried out in the same step by the reaction of water and an isocyanate group during the polymerization of the (meth) acrylic monomer in the sixth step. When using, it is necessary to make the fourth step of chain extension using a chain extender independent.)

  In the aqueous emulsion of the (meth) acrylic composite urethane resin composition, the structure in which the urethane resin is located around the (meth) acrylic resin forms one micelle. In other words, since the emulsifying group incorporated in the urethane resin acts as an emulsifier, the core-shell structure is arranged outside the micelle and has a (meth) acrylic resin containing no emulsifying group on the inside. The core-shell structure specifically refers to a structure in which components having different resin compositions exist in the same micelle and the resin composition is different between the central portion (core) and the outer shell portion (shell).

  In the present invention, a compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule (hereinafter referred to as “(meth) acrylic composite urethane resin composition aqueous emulsion”) Emulsified by using a neutralizing agent as a neutralizing agent, and emulsified, and then subjected to a salt exchange reaction with an alkali metal hydroxide to make the emulsified group inorganic. By converting the dissociated basic / radically polymerizable compound into a salt and introducing it into the resin composition, a completely aqueous emulsion substantially free of organic solvents and volatile organic compounds such as tertiary amines is obtained. . That is, the alkali metal hydroxide added after emulsification does not exhibit a catalytic action and forms an emulsifying group and an alkali metal salt. On the other hand, since the basic / radical polymerizable compound liberated by salt exchange for obtaining an alkali metal salt has a radical polymerizable functional group, the (meth) acrylic resin is polymerized during the polymerization of the (meth) acrylic monomer. Since it is incorporated by copolymerization, there is no problem of volatilization.

  The coating agent of the present invention contains such an aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention and a polyisocyanate curing agent, and does not have a problem of dissipation of harmful volatile components.

  According to the present invention, it exhibits excellent adhesiveness and solvent resistance when used in applications such as paints and adhesives such as plastic, paper, metal, wood, and fiber, and substantially uses organic solvents and tertiary grades. An aqueous emulsion of a (meth) acrylic composite urethane resin composition that does not contain volatile organic compounds such as amines and has no problems such as odor and toxicity, a method for producing the emulsion, and the (meth) acrylic composite urethane resin composition A coating using an aqueous emulsion is provided.

  Hereinafter, embodiments of the present invention will be described in detail according to the steps (1) to (6). In the present specification, “(meth) acryl” means “acryl and / or methacryl”. The same applies to “(meth) acrylate” and the like.

(1) First Step In the first step, two or more diisocyanate compounds in the molecule do not contain an active hydrogen group in the molecule, that is, in a (meth) acrylic monomer that is non-reactive with an isocyanate group. And a polyol compound containing two hydroxyl groups and a compound having two hydroxyl groups and one or more acidic functional groups in the molecule (hereinafter sometimes referred to as “ionic group-forming compound”) to be prepolymerized. To obtain a (meth) acrylic monomer solution of an isocyanate group-terminated urethane prepolymer.

  In this prepolymerization, the upper limit of the ratio NCO / OH (molar ratio) of the active hydrogen group in which the NCO group of the diisocyanate compound and the polyol compound and the ionic group forming compound are combined is usually 3.0 or less, preferably 2.0. The lower limit is usually 1.1 or more, preferably 1.2 or more. When NCO / OH (molar ratio) exceeds 3.0, the unreacted isocyanate monomer becomes excessive, resulting in poor emulsification. When the NCO / OH (molar ratio) is less than 1.1, the prepolymer has a high viscosity, so that the emulsification is poor, and when the viscosity is within the emulsifiable range, the formed coating film becomes brittle.

  The prepolymerization reaction is usually carried out at 50 to 100 ° C. In order to prevent the polymerization of the (meth) acrylic monomer described later by heat, a polymerization inhibitor such as p-methoxyphenol is added to the (meth) acrylic compound in the presence of air. It is preferable to add in the range of about 20 to 3000 ppm with respect to the monomer. At this time, organotin compounds such as dibutyltin dilaurate, dibutyltin dioctoate, stannous octoate, and tertiary amine compounds such as triethylamine and triethylenediamine are used as a catalyst for the urethanization reaction with respect to the isocyanate group-terminated urethane prepolymer. About 0.1 to 1% by weight.

  The diisocyanate is most preferably isophorone diisocyanate (IPDI) from the viewpoint of solubility and the weather resistance of the resulting aqueous emulsion. In addition, 2,4-tolylene diisocyanate (2,4-TDI), a mixture of 2,4-TDI and 2,6-tolylene diisocyanate (2,6-TDI), as long as there is no problem in performance, 4'-diphenylmethane diisocyanate, 1,4-phenylene diisocyanate, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate (HMDI), trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, xylylene It is also possible to use a mixture of diisocyanate, tetramethylxylylene diisocyanate and the like. Further, if necessary, a small amount of a polyfunctional isocyanate which is a reaction product with a trimer such as TDI, HMDI, or IPDI, or trimethylolpropane can be used.

  As the polyol compound containing two or more hydroxyl groups in the molecule, polyols generally used for urethane synthesis can be used. Specific examples include polyether polyol, polyester polyol, polyether ester polyol, polycarbonate polyol, polyolefin polyol, and silicon polyol.

  Examples of the polyether polyol include those obtained by ring-opening polymerization of a cyclic ether, such as polyethylene polyol, polypropylene polyol, and polytetramethylene polyol. Polyester polyols include dicarboxylic acids (succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, etc.) or their anhydrides and low molecular weight diols (ethylene glycol, diethylene glycol, triethylene glycol, Propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, polytetramethylene glycol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl 1,5-pentanediol, neopentyl glycol, 2-ethyl-1,3-hexane glycol, 2,2,4-trimethyl-1,3-pentanediol, 3,3-dimethylolheptane, 1,9- Nonanediol, 2-methyl-1,8- Of lactones to low molecular weight diols such as polyethylene adipate, polypropylene adipate, polybutylene adipate, polyhexamethylene adipate, polybutylene sebacate, etc. Examples thereof include those obtained by ring-opening polymerization such as polycaprolactone and polymethylvalerolactone. Examples of the polyether ester polyol include those obtained by ring-opening polymerization of a cyclic ether to a polyester polyol, those obtained by polycondensation of a polyether polyol and a dicarboxylic acid, such as poly (polytetramethylene ether) adipate, and the like. Examples of the polycarbonate polyol include polybutylene carbonate, polyhexamethylene carbonate, poly (3-methyl-1,5-pentylene) carbonate obtained by deglycolization or dealcoholization from a low molecular weight diol and alkylene carbonate or dialkyl carbonate. Examples of the polyolefin polyol include polybutadiene polyol, hydrogenated polybutadiene polyol, and polyisoprene polyol. Examples of the silicon polyol include polydimethylsiloxane polyol.

  As a polyol compound, these 1 type may be used independently, and 2 or more types may be mixed and used for it.

  Among these, polycarbonate polyol is preferable from the viewpoint of weather resistance. In addition, when a polyol in a solid state at 20 ° C. is used, the viscosity of the prepolymer at 20 ° C. is increased and emulsification may not be performed. Therefore, a liquid polycarbonate at 20 ° C. is preferable, and Tg is − If the temperature exceeds 20 ° C., the viscosity is high even in the vicinity of 20 ° C., so that the prepolymer has a high viscosity and may be poorly emulsified. Is a polycarbonate polyol containing 3-methyl-1,5-pentanediol, more preferably 3-methyl-1,5-pentanediol and 1,6-hexanediol in a molar ratio of 95: 5-40. : Polycarbonate polyol in the range of 60 is preferred. When the content of 1,6-hexanediol is increased more than this, the viscosity of the resulting prepolymer increases, which may cause poor emulsification.

  The upper limit of the number average molecular weight of this polyol compound is usually 3000 or less, preferably 2500 or less, and the lower limit is usually 1000 or more, preferably 1500 or more. If this molecular weight is too small, the function as a polyol will not be exhibited, and if it is too large, the viscosity of the resulting urethane prepolymer will increase, causing aggregates and poor dispersion during water dispersion, and reducing the amount of hydrophilic groups. Therefore, water dispersion tends to be poor.

  As an ionic group-forming compound containing two hydroxyl groups and one or more acidic functional groups in the molecule, compounds containing hydroxyl groups and carboxyl groups can be used. For example, dimethylolpropionic acid, dimethylolacetic acid, Alkanol carboxylic acids such as methylol butanoic acid, dimethylol heptanoic acid, dimethylol nonanoic acid, 1-carboxy-1,5-pentylenediamine, dihydroxybenzoic acid, 3,5-diaminobenzoic acid, polyoxypropylene triol and maleic anhydride And half ester compounds with acid and phthalic anhydride.

  As the ionic group forming compound, dimethylolpropionic acid and dimethylolbutanoic acid are preferable from the viewpoint of solubility and production, and dimethylolbutanoic acid is particularly preferable.

  Examples of the ionic group-forming compound include alkali metal sulfonates such as 2-sulfo-1,4-butanediol sodium salt and 5-sulfo-di-β-hydroxyethyl isophthalate, as long as there is no problem in physical properties. Sodium salt, N, N-bis (2-hydroxyethyl) aminoethylsulfonic acid tetramethylammonium salt, N, N-bis (2-hydroxyethyl) aminoethylsulfonic acid tetraethylammonium salt, N, N-bis (2- Hydroxyethyl) aminoethylsulfonic acid benzyltriethylammonium salt and the like can also be used.

  The ionic group forming compound is preferably used in such a manner that the number of acidic functional groups is within a range of number average molecular weight 500 / one acidic functional group or more and 7000 / one acidic functional group or less per urethane resin solid content. preferable. If this value is too small, the coating film properties and water resistance of the aqueous emulsion obtained tend to be poor. On the other hand, if it is too large, the self-emulsifying property of the urethane prepolymer will be insufficient, the average particle size of the dispersed particles will be increased, and the dispersion stability will be deteriorated, and it will be difficult to form a dense coating film. Further, when the urethane prepolymer solution is dispersed in water, by adding the polyoxyethylene group-containing acrylic monomer, the dispersion in water becomes good and a uniform and more stable dispersion can be obtained.

  As the (meth) acrylic monomer that does not contain an active hydrogen group in the molecule, a (meth) acrylic monomer that does not contain a hydroxyl group, a carboxyl group, a silanol group, an amino group, a glycidyl group, or the like can be used. For example, (meth) acrylic acid alkyl ester as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid Pentyl, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl methacrylate, lauryl (meth) acrylate, methoxyethyl (meth) acrylate, methoxy (meth) acrylate Butyl, ethoxybutyl (meth) acrylate, polyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, ethylene oxide (Meth) acrylate of id / tetrahydrofuran copolymer, (meth) acrylate of ethylene oxide / propylene oxide copolymer, polyethylene glycol monoallyl ether, etc., acrylamide, N-butoxymethyl (meth) acrylamide, N-methyl Those having an amide group such as acrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, diacetoneacrylamide, N-vinylformamide, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N -Monomers containing tertiary amino groups such as dimethylaminopropyl methacrylate, nitrogen-containing monomers such as N-vinylpyrrolidone, N-vinylimidazole, N-vinylcarbazole , Cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloaliphatic monomers such as isobornyl (meth) acrylate, aromatic monomers such as styrene, α-methylstyrene, phenyl methacrylate, vinyltriethoxysilane, γ -Silicon-containing monomers such as methacryloyloxypropyltrimethoxysilane, and fluorine-containing monomers such as octafluoropentyl (meth) acrylate and perfluorocyclohexyl (meth) acrylate. Other examples include divinylbenzene and trimethylolpropane triacrylate.

  Among the (meth) acrylic monomers, a compound containing an oxyethylene group that does not contain an active hydrogen group, such as polyethylene glycol (meth) acrylate, is used for the (meth) acrylic monomer solution of the urethane prepolymer during emulsification. Emulsification can be facilitated by improving hydrophilicity and decreasing the viscosity at the time of phase inversion.

Such a polyoxyethylene group-containing (meth) acrylic monomer may be usually added before being dispersed in water, that is, before or during neutralization in the second step. These monomers may be liquid or solid at room temperature. Liquid monomers can be added as they are, and solid monomers can be added after dissolution by heating. The addition amount of the polyoxyethylene group-containing (meth) acrylic monomer is preferably 0.5% by weight or more and 30% by weight or less in the total (meth) acrylic monomer. If the amount added is less than 0.5% by weight, the effect of the urethane prepolymer on the water dispersion of the (meth) acrylic monomer solution is insufficient. If the amount added exceeds 30% by weight, the final resin obtained Water resistance and heat resistance are reduced. In addition, from the viewpoint of the effect of lowering the viscosity of the urethane prepolymer solution and ease of handling, a monomer having about 2 to 20 ethylene oxide units (CH ₂ CH ₂ O) in the molecule is particularly preferable. By using such a polyoxyethylene group-containing (meth) acrylic monomer, the film-forming property when the formed resin coating film is dried is improved.

  In addition, when used as a surface protection or surface coating agent, from the viewpoint of physical properties of the obtained coating film, as the (meth) acrylic monomer, the Tg (when a plurality of (meth) acrylic monomers are used in combination) Are preferably those having a Tg) of 60 ° C. or higher determined by the calculation described below. Examples of such (meth) acrylic monomers include (meth) acrylic acid alkyl esters such as methyl methacrylate, ethyl methacrylate, isobornyl methacrylate, cyclopentyl methacrylate, and cyclohexyl methacrylate as long as they are homopolymers. It is also possible to use a mixture of a plurality of (meth) acrylic acid alkyl esters. When mixed and used, the Tg of the mixture can be calculated based on the mixing ratio from the Tg of the homopolymer of each (meth) acrylic acid alkyl ester. For example, if 50 parts by weight or less of butyl methacrylate having a Tg of less than 60 ° C. is mixed with 100 parts by weight of methyl methacrylate having a Tg of 60 ° C. or more, the calculated Tg can be 60 ° C. or more.

  In addition, the (meth) acrylic monomer which does not contain an active hydrogen group, such as the above-mentioned polyoxyethylene group-containing (meth) acrylic monomer, does not use the whole amount in the first step, and the urethane prepolymer in the second step and thereafter. You may add the (meth) acrylic-type monomer which does not contain an active hydrogen group to the polymer (meth) acrylic-type monomer solution. In this case, the addition time is not particularly limited, and for example, it can be added at any time before or after the neutralization step of the urethane prepolymer described later. Further, after the neutralized urethane prepolymer is dispersed in water, a (meth) acrylic monomer may be added to the dispersion.

(2) Second Step In the second step, the acidic functional group of the ionic group forming compound in the (meth) acrylic monomer solution of the urethane prepolymer obtained in the first step is neutralized. That is, in order to disperse the (meth) acrylic monomer solution of urethane prepolymer in water, the above ionic group forming compound is incorporated into the urethane prepolymer molecular chain, and a specific neutralizing agent necessary for ionic group formation is added. In addition, self-emulsifying property is imparted to the urethane prepolymer.

  In the present invention, a basic / radical polymerizable compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule is used as the neutralizing agent. In such a basic / radical polymerizable compound, after the salt exchange with an alkali metal hydroxide is liberated in the fifth step described later, in the polymerization step of the (meth) acrylic monomer in the sixth step, In the presence of the radical polymerizable functional group, it is re-incorporated into the polymer and fixed in the resin composition at the same time, so there is no problem of volatilization as in the conventional tertiary amine.

  Specific examples of the basic / radical polymerizable compound include acrylamide, N-butoxymethyl (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, and N-isopropyl (meta). ) Acrylamide, diacetone (meth) acrylamide, those having an amide group such as N-vinylformamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylamino Examples thereof include monomers having a tertiary amino group such as propyl (meth) acrylate, and monomers containing nitrogen such as N-vinylpyrrolidone, N-vinylimidazole and N-vinylcarbazole. These may be used alone or in combination of two or more.

  The upper limit of the neutralization rate with respect to acidic functional groups such as carboxyl groups of the urethane prepolymer obtained in the first step by such a basic / radical polymerizable compound is usually 100 mol% or less, and the lower limit is usually 0.00. 1 mol% or more, preferably 70 mol% or more. If the neutralization rate is less than 70%, the emulsification ability is insufficient, and the next process may not be sufficiently emulsified, and aggregates may be formed, or the emulsified state may be unstable and may be separated over time. However, if this neutralization rate is such that a stable emulsion can be obtained at the time when an alkali metal hydroxide is added in the fifth step described later, there is no practical problem.

  Since such a basic / radical polymerizable compound has a catalytic effect of activating an isocyanate group, it is not added as a prepolymerization reaction in the first step, but as an independent step after completion of the prepolymerization reaction. It is preferable to add. However, depending on the conditions for the prepolymerization reaction, a basic / radical polymerizable compound is added during the first step, and the neutralization step with the basic / radical polymerizable compound is not performed independently as the second step. It is also possible to shift directly to the emulsification step by adding water in the third step.

  In addition, as long as there is no problem in physical properties and toxicity, neutralizing agents for neutralizing the acidic functional groups of the urethane prepolymer to form salts to make them hydrophilic, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, Tertiary amines such as ethanolamine, triethylenediamine and dimethylaminoethanol can be used in combination with the basic / radical polymerizable compound.

(3) Third Step In the third step, water is added to and dispersed in the (meth) acrylic monomer solution of the urethane prepolymer after neutralization in the second step. As a method of dispersing in water, it is possible to disperse with a normal stirrer. Further, a homomixer, a homogenizer, a disper, a line mixer, or the like may be used.

(4) Fourth Step In the fourth step, chain extension is performed by adding a chain extender to the emulsion in the third step. When water is used as a chain extender, the chain extension is made particularly independent because water and an isocyanate group react with each other during polymerization of the (meth) acrylic monomer in the sixth step described later. There is no need to do it in the process. However, if required for required properties such as physical properties of the coating film, a chain extender other than water is added, and the chain extension process in the fourth step is made an independent process.

  As the chain extender other than water, known chain extenders having active hydrogen can be used. Examples thereof include diamines such as ethylenediamine, hexamethylenediamine, cyclohexanediamine, cyclohexylmethanediamine, and isophoronediamine, and hydrazine. It is done. These may be used alone or in combination of two or more.

(5) Fifth Step In the fifth step, the salt of the acidic functional group which is the emulsifying group in the second step and the basic / radical polymerizable compound is subjected to a salt exchange reaction using an alkali metal hydroxide. To form an inorganic salt of an acidic functional group.

  Examples of the alkali metal hydroxide used here include sodium hydroxide and potassium hydroxide. Other salts such as sodium hydrogen carbonate, sodium carbonate, potassium hydrogen carbonate, calcium carbonate and other alkali metals or alkaline earth metals and weak acids, magnesium hydroxide, calcium hydroxide, barium hydroxide, cesium hydroxide and other alkaline earth Similar metal hydroxides may be used in combination.

  Among these, a strong alkali metal hydroxide, a salt of an alkali metal or alkaline earth metal and a weak acid is preferable. More preferred are alkali metal hydroxides, specifically sodium hydroxide and / or potassium hydroxide. When a salt of an alkali metal and a weak acid is used, there is a possibility that a free weak acid may exist in the system due to the salt exchange reaction. Since carbonic acid is generated, the carbonic acid may decompose into water and carbon dioxide and foam.

  The alkali metal hydroxide is preferably added in an aqueous solution of usually 0.1% by weight or more, preferably 5% by weight or more and usually 60% by weight or less, preferably 50% by weight or less. If the concentration of this aqueous solution is too high, the resin may be precipitated due to strong alkalinity, and if it is too low, the solid content of the resin solution tends to be too low.

  The upper limit of the content of the emulsifying group formed by the salt exchange reaction in the fifth step, in other words, the inorganic salt of the acidic functional group in the resin is usually 0.450 meq / g or less (based on the resin solid content), preferably The lower limit is usually 0.130 meq / g or more, preferably 0.14 meq / g or more. If the content of the inorganic salt is less than 0.130 meq / g, the amount of hydrophilic groups is insufficient, or aggregates are generated during polymerization of the (meth) acrylic monomer in the next step, resulting in poor emulsification. If the content of the inorganic salt is more than 0.45 meq / g, the hydrophilicity becomes too high and the water resistance of the coating film may be lowered. Even when the content of the inorganic salt is less than 0.130 meq / g, salt exchange between the acidic functional group and the basic / radical polymerizable compound can be performed with the above-described tertiary amines. .

(6) Sixth Step A known radical polymerization method can be applied to the polymerization of the (meth) acrylic monomer in the sixth step. At the time of the polymerization in the sixth step, the basic / radical polymerizable compound removed by salt exchange in the fifth step is copolymerized with the (meth) acrylic monomer, and hardly remains as the monomer.

  As the polymerization initiator, both a water-soluble initiator and an oil-soluble initiator can be used. When using an oil-soluble initiator, it is preferable to add it to the (meth) acrylic monomer solution of the urethane prepolymer. . These polymerization initiators are usually used in the range of 0.05% by weight to 5% by weight with respect to the (meth) acrylic monomer, and the polymerization temperature is preferably 20 to 100 ° C. When the redox initiator is used, a polymerization temperature of 75 ° C. or lower is sufficient.

  Examples of the polymerization initiator include azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile, benzoyl peroxide, isobutyryl peroxide, octanoyl peroxide, cumyl peroxy octoate, t-butyl peroxy-2 -Organic peroxides such as ethyl hexanoate, t-butyl hydroperoxide, t-butyl peroxyacetate, lauryl peroxide, di-t-butyl peroxide, di-2-ethylhexyl peroxydine carbonate, persulfuric acid There are inorganic peroxide compounds such as potassium, ammonium persulfate, and hydrogen peroxide. The organic or inorganic peroxide compound can also be used as a redox initiator in combination with a reducing agent. Examples of the reducing agent include L-ascorbic acid, L-sorbic acid, sodium metabisulfite, ferric sulfate, ferric chloride, Rongalite and the like.

  When the polymerization initiator is added, any of a method in which the entire amount is initially charged, a method in which the entire amount is dropped over time, and a method in which a part is initially charged and the remainder is added later may be used. In addition, in order to cut off the polymerization and reduce the residual monomer, it is possible to add a polymerization initiator during the polymerization or after the polymerization is once completed to add the polymerization. At this time, the combination of polymerization initiators can be arbitrarily selected.

  In the polymerization step, the use of a known chain transfer agent such as octyl mercaptan, lauryl mercaptan, 2-mercaptoethanol, tert-dodecyl mercaptan, thioglycolic acid or the like may be used for the purpose of adjusting the molecular weight in the polymerization of the (meth) acrylic monomer. Is possible.

  When water is used as a chain extender, as described above, water and isocyanate groups react to cause chain extension during polymerization of the (meth) acrylic monomer, so that chain extension and (meth) acrylic monomer are performed. Can be polymerized in one step.

(7) Hydroxyl group-containing (meth) acrylic monomer addition step For the purpose of improving water resistance and stain resistance, a hydroxyl group-containing (meth) acrylic monomer is added to the reaction system. It is preferable to add after the emulsification of the step and before the chain extension step of the fourth step. In other words, it can be added during the prepolymerization reaction in the first step or after the completion of neutralization in the second step and before emulsification in the third step, but when added during the prepolymerization reaction in the first step Depending on the amount of the hydroxyl group-containing (meth) acrylic monomer added, the isocyanate group disappears during the prepolymerization reaction, and there is a possibility that sufficient physical properties cannot be obtained due to the short molecular weight. In the case of adding after neutralization and before emulsification in the third step, basically, the isocyanate group at the end of the urethane prepolymer reacts with the hydroxyl group-containing (meth) acrylic monomer as in the first step. , All of the isocyanate groups disappear, which may cause a problem in physical properties.

  Examples of hydroxyl-containing (meth) acrylic monomers include 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, and 2-hydroxypropyl. Methacrylate, 4-hydroxybutyl methacrylate, esterified product of (meth) acrylic acid and aliphatic or alicyclic glycol such as cyclohexanedimethanol monomethacrylate, polycaprolactone monoacrylate, polycaprolactone monomethacrylate, polytetramethylene ether monoacrylate, Esterification reaction of hydroxyl groups of polyols such as polytetramethylene ether methacrylate with (meth) acrylic acid, etc. Compound obtained, trimethylolpropane monoacrylate, trimethylolpropane diacrylate, glycerin monoacrylate, glycerin diacrylate, pentaerythritol monoacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, trimethylolpropane monomethacrylate, trimethylolpropane diacrylate A compound containing at least one hydroxyl group such as methacrylate, glycerol monomethacrylate, glycerol dimethacrylate, pentaerythritol monomethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, etc. ) Compounds obtained by esterification reaction with acrylic acid, etc., and Mixtures of these and the like. In addition, the (meth) acrylic monomer which does not contain the active hydrogen group described above can also be used by mixing with the above-mentioned hydroxyl group-containing (meth) acrylic monomer within a range where there is no problem in performance. These may be used alone or in combination of two or more.

  Among the hydroxyl group-containing (meth) acrylic monomers, (meth) acrylic acid esters derived from aliphatic or alicyclic glycols are preferred from the viewpoint of weather resistance and the like, and (meth) acrylic acid and 2 or more carbon atoms are preferred. Esterified products with 4 or less diols are more preferable, and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 4-hydroxybutyl acrylate are particularly preferable from the viewpoints of water resistance and coating film properties.

  The content of the hydroxyl group-containing (meth) acrylic monomer in the resin is usually 50 mg-KOH / g or less, preferably 25 mg-KOH / g, and the lower limit is usually 1 mg-KOH as the hydroxyl value in terms of resin solid content. / G or more, preferably 3 mg-KOH / g or more. When the hydroxyl value is less than 1 mg-KOH / g, the hydroxyl group does not contribute as a crosslinking point, so the stain resistance is not improved. When the hydroxyl value exceeds 50 mg-KOH / g, the amount of hydroxyl group increases, It is presumed that the contamination resistance, particularly water resistance, decreases due to the improved hydrophilicity of the membrane itself.

  As described above, the specific production methods for producing the aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention include the methods [I] to [IV]. However, in the following methods [I] to [IV], as described above, the first step and the second step can be performed simultaneously.

[I] Method through the following steps (1) to (6)
(1) A prepolymer obtained by reacting a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and an ionic group forming compound in a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule. A first step of performing the conversion.
(2) Second step of neutralizing the acidic functional group in the urethane prepolymer obtained in the first step with a basic / radical polymerizable compound.
(3) The third step of adding water to emulsify.
(4) Fourth step of chain extension using a chain extender other than water.
(5) A fifth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(6) Sixth step of polymerizing the (meth) acrylic monomer (in this step, the basic / radical polymerizable compound liberated by the salt exchange reaction of the previous step is taken into the copolymer).

[II] Method through the following steps (1) to (7)
(1) A prepolymer obtained by reacting a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and an ionic group forming compound in a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule. A first step of performing the conversion.
(2) Second step of neutralizing the acidic functional group in the urethane prepolymer obtained in the first step with a basic / radical polymerizable compound.
(3) The third step of adding water to emulsify.
(4) Fourth step of mixing a hydroxyl group-containing (meth) acrylic monomer.
(5) A fifth step of chain extension using a chain extender other than water.
(6) A sixth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(7) Seventh step of polymerizing the (meth) acrylic monomer (in this step, the basic / radical polymerizable compound liberated by the salt exchange reaction of the previous step is taken into the copolymer).

[III] A method through the following steps (1) to (5)
(1) A prepolymer obtained by reacting a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and an ionic group forming compound in a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule. A first step of performing the conversion.
(2) Second step of neutralizing the acidic functional group in the urethane prepolymer obtained in the first step with a basic / radical polymerizable compound.
(3) The third step of adding water to emulsify.
(4) A fourth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(5) The fifth step in which the chain is extended with water and the (meth) acrylic monomer is polymerized (in this step, the basic / radical polymerizable compound released by the salt exchange reaction in the previous step is contained in the copolymer) Is taken in.)

[IV] Method through the following steps (1) to (6)
(1) A prepolymer obtained by reacting a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and an ionic group forming compound in a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule. A first step of performing the conversion.
(2) Second step of neutralizing the acidic functional group in the urethane prepolymer obtained in the first step with a basic / radical polymerizable compound.
(3) The third step of adding water to emulsify.
(4) Fourth step of mixing a hydroxyl group-containing (meth) acrylic monomer.
(5) A fifth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(6) Sixth step of extending the chain with water and polymerizing the (meth) acrylic monomer (in this step, the basic / radical polymerizable compound released by the salt exchange reaction in the previous step is contained in the copolymer) Is taken in.)

  The solid content weight ratio of the urethane resin and the (meth) acrylic resin in the aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention obtained through the above steps is in the range of 25/75 to 60/40. It is preferable. Moreover, the upper limit of the solid content (nonvolatile content) is usually 50% by weight or less, preferably 40% by weight or less, and the lower limit is usually 5% by weight or more, preferably 30% by weight or more. If the solid (non-volatile) content is too high, it will not be sufficiently emulsified, and if it is too low, the resin concentration will be too low, and the coating film will be too thin for use as a surface coating agent, etc., and its effect will not be fully demonstrated. there is a possibility.

  The aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention is excellent in mechanical properties, adhesion to a substrate, weather resistance, blocking resistance, solvent resistance, water resistance, pigment dispersibility and the like. , Paints, inks, adhesives, various binder resins, coating materials, and primers. Also, as necessary for each application, known additives such as pigments, dyes, leveling agents, thickeners, antifoaming agents, crosslinking agents, light-resistant stabilizers, film-forming aids, etc. ) Can be used in a range of about 20 wt% to 70 wt%.

  The coating agent of the present invention comprises such an aqueous emulsion of the (meth) acrylic composite urethane resin composition of the present invention and a polyisocyanate curing agent as essential components.

  The polyisocyanate curing agent is added to improve adhesion to a plastic substrate or the like and stain resistance. Examples of water-dispersed polyisocyanate curing agents that can be used for this purpose include polyisocyanate compounds having an isocyanate group with an average number of functional groups of two or more, and one active hydrogen group per molecule and a nonionic type. The thing to which the compound containing a hydrophilic group was added is mentioned.

  Examples of the polyisocyanate compound having two or more isocyanate groups in one molecule include polyisocyanurate compounds in which an isocyanurate ring is introduced (isocyanuration reaction) by trimerization of the polyisocyanate compound, organic diisocyanate and polyfunctional activity. Examples thereof include an isocyanate group-terminated polyurethane polyisocyanate compound obtained by a reaction with a hydrogen compound. Each of these can be obtained by a conventionally known method.

  The polyisocyanate compound is preferably an aliphatic diisocyanate or an alicyclic diisocyanate from the viewpoint of the reactivity between water and isocyanate when dispersed in water. Of these, aliphatic diisocyanates, particularly hexamethylene diisocyanate, are preferred in consideration of water dispersibility.

  Specific examples of the compound containing one active hydrogen group and nonionic hydrophilic group in one molecule include methoxypolyethylene glycol, ethoxypolyethylene glycol, butoxypolyethylene glycol, and mixed alcohols having 13 to 15 carbon atoms. Examples include ethylene oxide adducts of alkyl alcohols such as ethylene oxide, phenoxypolyethylene glycol, and methoxypolyethylene glycol monoallyl ether.

  The reaction (urethanization reaction) between the polyisocyanate and the compound containing one active hydrogen group and a nonionic hydrophilic group in one molecule is performed by a conventionally known method.

  The temperature in this urethanization reaction is usually selected from the range of 10 to 90 ° C., and a catalyst for that purpose is not particularly required. However, in some cases, organotin catalysts such as dibutyltin dilaurate and dibutyltin dioctate, lead octoate It is also effective to use an organic lead catalyst such as triethylamine, dimethyloctylamine, diazabicycloundecene or the like. The progress of the urethanization reaction can be monitored by measuring the NCO content in the middle of the reaction.

  These reactions can be carried out without solvent or in a solvent. From the viewpoint of commonality before and after the reaction, it is preferable to use one or more inert solvents such as ketones, acetates, and hydrocarbons used in the above isocyanuration reaction as the solvent to be used. .

  In the coating agent of the present invention, the mixing ratio of the (meth) acrylic composite urethane resin composition aqueous emulsion of the present invention and the polyisocyanate curing agent is preferably 1 to 100: 1 in terms of solid content weight ratio. If the amount of the aqueous emulsion of the resin composition is larger than this range, the crosslinking density is insufficient and the stain resistance tends to be lowered, and if it is less, the polyisocyanate group becomes excessive and the physical properties of the coating film may be lowered.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
Example 1
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port, and stirring device, 210.9 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n (number of ethylene oxide units in the molecule) = 9) and 13.8 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
547.5 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
10.1 g of 34.8 wt% aqueous sodium hydroxide was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.
About the obtained aqueous emulsion, the average particle diameter and viscosity of the emulsion polymer were measured by the following methods, and the results are shown in Table 1.
<Average particle size>
Measurement was performed using “Microtrac UPA-150” manufactured by Nikkiso Co., Ltd.
<Viscosity>
Using “VISCONIC-EMD” manufactured by Tokyo Keiki Co., Ltd., measurement was performed at a rotation speed of 100 rpm with a 1 ° 34 ′ rotor.

Example 2
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port and stirring device, 211.8 g of methyl methacrylate, 32.5 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.6 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g (NCO / OH molar ratio = 1.25), heated to 80 ° C., 5 hours An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.4 g of methoxypolyethylene glycol methacrylate (n = 9) and 13.8 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
549.7 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
6.1 g of a 34.8 wt% aqueous sodium hydroxide solution was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.7 g of demineralized water, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 3
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port and stirring device, 211.6 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 13.1 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
547.5 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
10.1 g of 34.8 wt% aqueous sodium hydroxide was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 4
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port, and stirring device, 223.3 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 1.4 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
When 547.5 g of demineralized water was added dropwise, the urethane prepolymer solution became non-uniformly dispersed.
(Process 4)
10.1 g of 34.8 wt% aqueous sodium hydroxide was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 5
A resin composition aqueous emulsion was produced by the following steps 1 to 6.
(Process 1)
To a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port, and stirring device, 200.5 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 13.8 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
547.5 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
10.4 g of 2-hydroxyethyl methacrylate (HEMA) was added.
(Process 5)
10.1 g of 34.8 wt% aqueous sodium hydroxide was added.
(Step 6)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 6
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, a thermometer, a charging port and a stirring device, 119.2 g of methyl methacrylate, 52.9 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 119.0 g, dimethylolbutanoic acid 17.6 g, p-methoxyphenol 0.01 g (NCO / OH molar ratio = 1.33), heated to 80 ° C., 5 hours An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.2 g of methoxypolyethylene glycol methacrylate (n = 9) and 18.7 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
579.6 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
13.7 g of a 34.8 wt% aqueous sodium hydroxide solution was added.
(Process 5)
While introducing nitrogen gas into the flask, 1.6 g of potassium persulfate was dissolved in 60.5 g of demineralized water, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 7
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, a thermometer, a charging port and a stirrer, 210.1 g of methyl methacrylate, 32.3 g of isophorone diisocyanate, and a polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.1 g, dimethylolbutanoic acid 12.9 g and p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.2 g of methoxypolyethylene glycol methacrylate (n = 9) and 13.7 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
548.7 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
10.7 g of a 45.9 wt% aqueous potassium hydroxide solution was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.0 g of demineralized water, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 8
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port and stirring device, 212.1 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 12.6 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
547.5 g of demineralized water was added dropwise to emulsify the urethane prepolymer solution.
(Process 4)
10.1 g of 34.8 wt% aqueous sodium hydroxide was added.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 9
A resin composition aqueous emulsion was produced by the following steps 1 to 5.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, a thermometer, a charging port, and a stirrer, 215.5 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and a polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured, Tg = −33 ° C.) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g were charged (NCO / OH molar ratio = 1.25), and the temperature was raised to 80 ° C. for 5 hours. An acrylic monomer solution of urethane prepolymer was obtained by reaction.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 9.2 g of 2-vinylpyridine (2-VP) were added and mixed uniformly.
(Process 3)
When 547.5 g of demineralized water was added dropwise, the urethane prepolymer solution was dispersed in water non-uniformly.
(Process 4)
10.1 g of 34.8% by weight sodium hydroxide aqueous solution was added and emulsified.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.4 g of demineralized water and added, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the temperature was kept at 75 ° C. and the reaction was allowed to proceed for 3 hours to cool the urethane prepolymer with water and polymerize the acrylic monomer. After 3 hours, the infrared absorption of the isocyanate group disappeared, and from the solid content measurement, it was confirmed that the conversion rate of the acrylic monomer reached 99% or more, and the resin composition aqueous emulsion having a solid content of 35% by weight Got.

  For the obtained aqueous emulsion, the average particle size and viscosity of the emulsion polymer were measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 10
In Example 9, except that Step 1 and Step 2 were changed as follows, a resin composition aqueous emulsion was produced in the same manner, and the average particle diameter and viscosity of the emulsion polymer were similarly measured, and the results were It is shown in Table 1.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, a thermometer, a charging port, and a stirrer, 216.4 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and a polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Manufactured) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g (NCO / OH molar ratio = 1.25), heated to 80 ° C., reacted for 5 hours, urethane prepolymer An acrylic monomer solution was obtained.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 8.2 g of 1-vinylimidazole (1-VI) were added and mixed uniformly.

Example 11
In Example 9, except that Step 1 and Step 2 were changed as follows, a resin composition aqueous emulsion was produced in the same manner, and the average particle diameter and viscosity of the emulsion polymer were similarly measured, and the results were It is shown in Table 1.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port, and stirrer, 216.0 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray) Made) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g was charged (NCO / OH molar ratio = 1.25), heated to 80 ° C. and reacted for 5 hours to make urethane prepolymer An acrylic monomer solution was obtained.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 8.7 g of N, N-dimethylacrylamide (DMAA) were added and mixed uniformly.

Example 12
In Example 9, except that Step 1 and Step 2 were changed as follows, a resin composition aqueous emulsion was produced in the same manner, and the average particle diameter and viscosity of the emulsion polymer were similarly measured, and the results were It is shown in Table 1.
(Process 1)
A 4 L 2 L separable flask equipped with a condenser, a thermometer, a charging port and a stirrer was charged with 213.5 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray). Manufactured) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g (NCO / OH molar ratio = 1.25), heated to 80 ° C., reacted for 5 hours, urethane prepolymer An acrylic monomer solution was obtained.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 11.1 g of N, N-diethylacrylamide (DEAA) were added and mixed uniformly.

Example 13
In Example 9, except that Step 1 and Step 2 were changed as follows, a resin composition aqueous emulsion was produced in the same manner, and the average particle diameter and viscosity of the emulsion polymer were similarly measured, and the results were It is shown in Table 1.
(Process 1)
Into a four-necked 2 L separable flask equipped with a condenser, thermometer, charging port, and stirrer, a polycarbonate diol (Kuraray polyol C-2090: Kuraray) having 220.0 g of methyl methacrylate, 32.4 g of isophorone diisocyanate, and an average molecular weight of 2000 was used. Manufactured) 58.3 g, dimethylolbutanoic acid 13.0 g, p-methoxyphenol 0.02 g (NCO / OH molar ratio = 1.25), heated to 80 ° C., reacted for 5 hours, urethane prepolymer An acrylic monomer solution was obtained.
(Process 2)
After cooling to 40 ° C., 17.3 g of methoxypolyethylene glycol methacrylate (n = 9) and 4.6 g of acrylonitrile (AN) were added and mixed uniformly.

Comparative Example 1
Production of a resin composition aqueous emulsion was attempted by the following steps 1 to 5, but in step 5, the emulsified polymer was aggregated and could not be produced.
(Process 1)
A 4 L 2 L separable flask equipped with a condenser, a thermometer, a charging port, and a stirrer was charged with 213.4 g of methyl methacrylate, 32.6 g of isophorone diisocyanate, and a polycarbonate diol having an average molecular weight of 2000 (Kuraray polyol C-2090: Kuraray). (Made) 58.6 g, dimethylol butanoic acid 13.0 g and p-methoxyphenol 0.02 g were charged, heated to 80 ° C. and reacted for 5 hours to obtain an acrylic monomer solution of urethane prepolymer.
(Process 2)
After cooling to 40 ° C., 17.4 g of methoxypolyethylene glycol methacrylate (n = 9) and 12.4 g of N, N-dimethylaminoethyl methacrylate (DMAEM) were added and mixed uniformly.
(Process 3)
Although 549.7 g of demineralized water was added dropwise, phase inversion was not possible, resulting in poor emulsification.
(Process 4)
5.1 g of 34.8 wt% aqueous sodium hydroxide solution was added and emulsified.
(Process 5)
While introducing nitrogen gas into the flask, 2.4 g of potassium persulfate was dissolved in 94.8 g of demineralized water, and the temperature of the dispersion was gradually raised. Although heat was generated at around 50 ° C., the emulsion polymer then aggregated and became unmanufacturable.

  In Table 1, the reaction conditions (neutralization rate, etc.) in each example, the urethane resin / acrylic resin ratio of the produced aqueous resin composition emulsion, and the amount of hydrophilic groups (values to be produced in Comparative Example 1) are also shown. did.

  From Table 1, according to this invention, the (meth) acryl composite urethane type resin composition aqueous emulsion containing the urethane resin part which has the acidic functional group neutralized with the inorganic salt, and the (meth) acrylic resin part is provided. You can see that

  The obtained (meth) acrylic composite urethane resin composition aqueous emulsion was subjected to gas chromatography (column: DB-1 (manufactured by GL Sciences, 0.32 mm × 30 m × 0.25 μm), injection temperature 250. C., column temperature 80.fwdarw.200.degree. C., detector temperature 300.degree. C.), the basic / radical polymerizable compound released by the salt exchange reaction with sodium hydroxide or potassium hydroxide is taken into the resin, It was confirmed that there was no problem of volatilization.

  The (meth) acrylic composite urethane resin composition aqueous emulsion of the present invention exhibits excellent adhesion and solvent resistance, and substantially does not contain volatile organic compounds such as organic solvents and tertiary amines. Since there are no problems such as odor and toxicity, it is useful for applications such as paints and adhesives such as plastic, paper, metal, wood and fiber.

Claims (6)

  A (meth) acrylic composite urethane resin composition aqueous emulsion comprising a urethane resin part having an acidic functional group neutralized with an inorganic salt and a (meth) acrylic resin part in the same micelle.   2. The polymer of claim 1, wherein the (meth) acrylic resin portion is a (meth) acrylic monomer and a compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule. An aqueous emulsion of a (meth) acrylic composite urethane resin composition, characterized in that:   3. The (meth) acrylic composite urethane resin composition aqueous emulsion according to claim 1 or 2, wherein the acidic functional group is a carboxyl group and the counter ion is sodium and / or potassium.   4. The compound according to claim 2 or 3, wherein the compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule is dimethylaminoethyl acrylate and / or dimethylaminoethyl methacrylate. A (meth) acrylic composite urethane resin composition aqueous emulsion. A method for producing an aqueous emulsion of the (meth) acrylic composite urethane resin composition according to any one of claims 1 to 4, comprising the following steps (1) to (6): (Meth) acrylic composite urethane-based resin composition aqueous emulsion manufacturing method.
(1) In a (meth) acrylic monomer that does not contain an active hydrogen group in the molecule, a polyisocyanate compound, a polyol compound containing two or more hydroxyl groups in the molecule, and two hydroxyl groups and one in the molecule The 1st process which makes the compound which has the above acidic functional group react, and prepolymerizes.
(2) A compound having at least one basic functional group and at least one radical polymerizable functional group in the molecule, wherein the acidic functional group in the urethane prepolymer obtained in the first step is neutralized. 2 steps.
(3) A third step of adding water to emulsify.
(4) Fourth step of chain extension using a chain extender.
(5) A fifth step of neutralizing 0.130 meq / g or more of the acidic functional group by salt exchange with an alkali metal hydroxide.
(6) A sixth step of polymerizing the (meth) acrylic monomer.
(However, when water is used as the chain extender, the fourth step does not need to be an independent step, and in the sixth step, a chain extension reaction can be performed during the polymerization of the (meth) acrylic monomer. it can.)   A coating agent comprising an aqueous curable resin composition containing the aqueous (meth) acrylic composite urethane resin composition emulsion according to any one of claims 1 to 4 and a polyisocyanate curing agent.