JP7288168B2 - Aqueous resin composition, coating agent, and article - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aqueous resin composition, a coating agent, and an article having a cured coating film of the coating agent.

In recent years, the development of high-performance materials that combine the properties of inorganic and organic materials has been widely carried out in various industrial fields. It is generally known that coating films obtained from organic materials are excellent in flexibility and workability. Under such circumstances, a water-based resin in which an inorganic material and an organic material are combined has been proposed (see, for example, Patent Document 1). A coating film having high weather resistance, crack resistance, substrate conformability, etc. can be obtained from this polyurethane composite material, but the flexibility of the coating film may be insufficient in low-temperature environments. In addition, the same tendency was observed in applications for formulating pigments, fillers, and the like.

Therefore, there has been a demand for a material capable of forming a coating film with excellent weather resistance and flexibility even in low-temperature environments and in applications where pigments, fillers, etc. are formulated.

JP 2010-1457 A

The problem to be solved by the present invention is an aqueous resin composition capable of forming a coating film having excellent pigment dispersibility, coating film appearance, low-temperature flexibility, adhesion, water resistance, weather resistance, and bleed-out resistance. It is to provide things. Another object of the present invention is to provide a coating agent using the aqueous resin composition and an article coated with the coating agent.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that, among composite resins in which a polyurethane having a hydrophilic group and a vinyl polymer are bonded via polysiloxane, a specific proportion of polysiloxane-derived The inventors have found that an aqueous resin composition containing a component, a plasticizer, and an aqueous medium can solve the above problems, and have completed the present invention.

That is, an aqueous resin containing a composite resin (A) in which a polyurethane (a1) having a hydrophilic group and a vinyl polymer (a2) are bonded via a polysiloxane (a3), a plasticizer (B), and an aqueous medium In the composition, the bond between the polyurethane (a1) having a hydrophilic group and the polysiloxane (a3) is the hydrolyzable silyl group and/or silanol group of the polyurethane (a1) and the polysiloxane ( It is a condensation bond with the hydrolyzable silyl group and/or silanol group of a3), and the bond between the vinyl polymer (a2) and the polysiloxane (a3) is a hydrolysis bond of the vinyl polymer (a2). is a condensation bond between a silyl group and/or a silanol group and a hydrolyzable silyl group and/or a silanol group possessed by the polysiloxane (a3), and is derived from the polysiloxane (a3) in the composite resin (A) The mass ratio of the structure is in the range of 15 to 55 mass%, and the content of the plasticizer (B) with respect to 100 mass parts of the composite resin (A) is in the range of 0.1 to 45 mass parts. It relates to a water-based resin composition.

The aqueous resin composition of the present invention has excellent pigment dispersibility and can form a coating film having excellent various physical properties such as low-temperature flexibility and weather resistance. Galvanized steel sheets, aluminum-zinc alloy steel sheets used for civil engineering materials such as walls and drains, home appliances, industrial machinery, automobile parts, etc., aluminum sheets, aluminum alloy sheets, electromagnetic steel sheets, copper sheets, It can be suitably used as a coating agent for metal substrates such as stainless steel plates, mobile phones, home electric appliances, OA equipment, plastic products such as automobile interior materials, and the like.

In addition, since the aqueous resin composition of the present invention can form a coating film having excellent substrate followability, it can be used for adhesion of various functional films and members constituting film structure buildings such as tent sheets, solar cells, and polarizing plates. It can be used as an agent, etc.

The aqueous resin composition of the present invention comprises a composite resin (A) in which a polyurethane (a1) having a hydrophilic group and a vinyl polymer (a2) are bonded via a polysiloxane (a3), a plasticizer (B), and An aqueous resin composition containing an aqueous medium, wherein the bond between the polyurethane (a1) having a hydrophilic group and the polysiloxane (a3) is a hydrolyzable silyl group and/or A silanol group and a hydrolyzable silyl group and/or a silanol group possessed by the polysiloxane (a3) are condensed bonds, and the bond between the vinyl polymer (a2) and the polysiloxane (a3) is a condensation bond between the vinyl polymer (a2) is a condensation bond between the hydrolyzable silyl group and/or silanol group of the polysiloxane (a3) and the hydrolyzable silyl group and/or silanol group of the polysiloxane (a3); The mass ratio of the structure derived from polysiloxane (a3) is in the range of 15 to 55% by mass, and the content of the plasticizer (B) with respect to 100 parts by mass of the composite resin (A) is 0.1 to 45 parts by mass. It is a range.

First, the composite resin (A) will be described. The composite resin (A) is obtained by bonding a polyurethane (a1) having a hydrophilic group and a vinyl polymer (a2) via a polysiloxane (a3).

The composite resin (A) is dispersed in an aqueous medium, but part of the composite resin (A) may be dissolved in the aqueous medium. The composite resin (A) dispersed in the aqueous medium has an average particle size of 10 to 500 nm, so that it forms a coating film that has excellent substrate followability, durability such as crack resistance, and weather resistance. It is preferable to The average particle size referred to here is a value measured by a method of obtaining a particle size distribution based on the measurement principle of detecting dynamic scattering light of particles.

In addition, the composite resin (A) has a structure derived from polysiloxane (a3) in an amount of 15 to 55% by mass based on the total composite resin (A) in order to form a coating film having excellent durability and weather resistance. It is important to have For example, in a composite resin in which the mass ratio of the polysiloxane (a3) is 10% by mass, a coating film having relatively good substrate conformability can be formed, but such a coating film has poor durability and weather resistance. It is not sufficient, and peeling from the substrate may occur over time.

On the other hand, the composite resin-containing composition in which the mass ratio of the structure derived from the polysiloxane (a3) is 65% by mass has the structure derived from the polyurethane (a1) having a hydrophilic group and the structure derived from the vinyl polymer (a2). The lower the mass ratio, the lower the film-forming properties, and as a result, cracks may occur on the surface of the coating film.

The mass ratio of the structure derived from the polysiloxane (a3) in the composite resin (A) is in the range of 20 to 35% by mass, so that excellent durability, weather resistance, and substrate conformability are achieved. It is preferable for forming a coating film.

The structure derived from the polysiloxane (a3) means that the main chain constituting the connecting portion between the vinyl polymer (a2) and the polyurethane (a1) having a hydrophilic group that constitutes the composite resin (A) is an oxygen A structure consisting of atoms and silicon atoms. Further, the mass ratio of the structure derived from the polysiloxane (a3) is based on the charging ratio of the raw materials used in the production of the composite resin (A), and the methanol that can be generated by the hydrolysis condensation reaction of the polysiloxane (a3) etc. This value is calculated taking into account the production of by-products such as ethanol and ethanol.

Moreover, the composite resin (A) must have a hydrophilic group in order to be stably dispersed in an aqueous medium.

The hydrophilic group must be present mainly in the polyurethane (a1) constituting the outer layer of the composite resin (A), but if necessary, it may be present in the vinyl polymer (a2) Also good.

An anionic group, a cationic group, and a nonionic group can be used as the hydrophilic group, and among these, the anionic group is more preferably used.

As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, or the like can be used. or a sulfonate group is preferred for producing a composite resin having good water dispersibility.

Examples of basic compounds that can be used for neutralizing the anionic group include organic amines such as ammonia, triethylamine, pyridine and morpholine; alkanolamines such as monoethanolamine; and Na, K, Li, Ca, and the like. metal base compounds containing

When a carboxylate group or a sulfonate group is used as the anionic group, they should be present in the range of 50 to 1000 mmol/kg with respect to the entire composite resin (A). It is preferable for maintaining dispersion stability.

Moreover, as said cationic group, a tertiary amino group etc. can be used, for example. Examples of acids that can be used for neutralizing part or all of the tertiary amino groups include organic acids such as acetic acid, propionic acid, lactic acid and maleic acid, and sulfonic acid and methanesulfonic acid. Organic sulfonic acids and inorganic acids such as hydrochloric acid, sulfuric acid, orthophosphoric acid and orthophosphorous acid may be used alone or in combination of two or more.

Examples of quaternizing agents that can be used for quaternizing part or all of the tertiary amino groups include dialkyl sulfates such as dimethyl sulfate and diethyl sulfate, methyl chloride, and ethyl chloride. , alkyl halides such as benzyl chloride, alkyls such as methyl methanesulfonate and methyl p-toluenesulfonate, and epoxies such as ethylene oxide, propylene oxide and epichlorohydrin may be used alone or in combination of two or more.

Examples of the nonionic group include polyoxyalkylene groups such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(oxyethylene-oxypropylene) group, and a polyoxyethylene-polyoxypropylene group. groups can be used. Among them, it is preferable to use a polyoxyalkylene group having an oxyethylene unit in order to further improve the hydrophilicity.

Further, in the composite resin (A), the mass ratio [(a2)/(a1)] of the polyurethane (a1) having a hydrophilic group and the vinyl polymer (a2) is 20/1 to 1/ It is preferable to use one in the range of 20 in order to form a coating film having excellent substrate followability and excellent durability and weather resistance, and it is in the range of 10/1 to 1/10. More preferably, the range of 5/1 to 1/5 is particularly preferred.

Further, the bond between the hydrophilic group-containing polyurethane (a1) and the polysiloxane (a3) is, for example, the hydrolyzable silyl group and/or silanol group of the hydrophilic group-containing polyurethane (a1) and the above-mentioned There is a condensation bond with the hydrolyzable silyl group and/or silanol group of the polysiloxane (a3). Further, the bond between the vinyl polymer (a2) and the polysiloxane (a3) is formed by the hydrolyzable silyl group and/or silanol group of the vinyl polymer (a2) and the hydrolyzable group of the polysiloxane (a3). It is a condensation bond with a decomposable silyl group and/or a silanol group.

Next, the hydrophilic group-containing polyurethane (a1) constituting the composite resin (A) will be described.

The hydrophilic group-containing polyurethane (a1) is an essential component for imparting excellent substrate conformability to the aqueous resin composition of the present invention.

As the hydrophilic group-containing polyurethane (a1), various types can be used. It is preferable to use one having a number average molecular weight of up to 10,000 in order to form a coating film excellent in substrate followability, durability and weather resistance.

The hydrophilic group-containing polyurethane (a1) must have a hydrophilic group in order to impart water dispersion stability to the composite resin (A). Hydrophilic groups are preferably present in the range of 50 to 1,000 mmol/kg with respect to the entire polyurethane (a1) having hydrophilic groups in order to impart better water dispersibility to the composite resin. .

As the polyurethane (a1) having a hydrophilic group, for example, a polyurethane obtained by reacting a polyol and a polyisocyanate can be used. The hydrophilic group possessed by the polyurethane (a1) having a hydrophilic group can be obtained, for example, by using a polyol having a hydrophilic group as one component constituting the polyol. can be introduced into

As polyols that can be used in the production of the hydrophilic group-containing polyurethane (a1), for example, the hydrophilic group-containing polyols and other polyols can be used in combination.

Examples of polyols having hydrophilic groups include 2,2′-dimethylolpropionic acid, 2,2′-dimethylolbutanoic acid, 2,2′-dimethylolbutyric acid, 2,2′-dimethylolvaleric acid, and the like. Polyols having carboxyl groups and polyols having sulfonic acid groups such as 5-sulfoisophthalic acid, sulfoterephthalic acid, 4-sulfophthalic acid, and 5[4-sulfophenoxy]isophthalic acid can be used. Examples of the polyol having a hydrophilic group include a polyester polyol having a hydrophilic group obtained by reacting the aforementioned polyol having a hydrophilic group with a low molecular weight with various polycarboxylic acids such as adipic acid. can also be used.

Other polyols that can be used in combination with the polyol having a hydrophilic group can be appropriately used depending on the properties required for the aqueous resin composition of the present invention, the application of the aqueous resin composition, etc. For example, polyether polyols, polyester polyols and polycarbonate polyols can be used.

Since the polyether polyol can impart particularly excellent substrate conformability to the aqueous resin composition of the present invention, it is preferably used in combination with the polyol having a hydrophilic group.

As the polyether polyol, for example, one obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator can be used.

Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, and glycerin. , trimethylolethane, trimethylolpropane, and the like can be used.

Examples of alkylene oxides that can be used include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

Examples of the polyester polyols include aliphatic polyester polyols and aromatic polyester polyols obtained by esterification reaction of low molecular weight polyols and polycarboxylic acids, and ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone. A polyester obtained by the above method, a copolymerized polyester thereof, or the like can be used.

As the low-molecular-weight polyol, for example, ethylene glycol, propylene glycol and the like can be used.

Examples of polycarboxylic acids that can be used include succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and anhydrides or ester-forming derivatives thereof. .

Polycarbonate polyols that can be used in the production of the hydrophilic group-containing polyurethane (a1) are also preferred for significantly improving the adhesion of the water-based resin composition of the present invention to plastic substrates. As the polycarbonate polyol, for example, one obtained by reacting a carbonate ester and a polyol, or one obtained by reacting phosgene with bisphenol A or the like can be used.

As the carbonic acid ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used.

Examples of polyols that can react with the carbonate ester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3 -butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7- heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 3-methyl-1,5-pentanediol, 2 -ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethylpropanediol, 2-methyl-1,8- Relatively low molecular weight dihydroxy compounds such as octanediol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol-A, bisphenol-F, 4,4'-biphenol, etc. , polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like, and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate and polycaprolactone.

As the polycarbonate polyol, the one obtained by reacting the dimethyl carbonate and the 1,6-hexanediol is used to achieve both excellent adhesion to plastic substrates and excellent substrate followability. It is more preferable because it can be done and is inexpensive.

Moreover, as the polycarbonate polyol, it is preferable to use one having a number average molecular weight in the range of 500 to 6,000.

The polycarbonate polyol is used in a range of 30 to 95% by mass based on the total amount of the polyol and polyisocyanate used in the production of the polyurethane (a1). It is preferable to achieve both

The water-based resin composition of the present invention obtained using the polycarbonate polyol is, among others, a polycarbonate base material, a polyester base material, an acrylonitrile-butadiene-styrene base material, a polyacrylic base material, a polystyrene base material, a polyurethane base material, and an epoxy resin composition. It has excellent adhesion to various plastic substrates, which are generally known as difficult-to-adhere substrates, such as resin substrates, polyvinyl chloride substrates, and polyamide substrates. can be used for

Examples of the polyisocyanate used in producing the hydrophilic group-containing polyurethane (a1) include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate and naphthalene diisocyanate, hexamethylene diisocyanate, and lysine. Aliphatic or aliphatic cyclic structure-containing diisocyanates such as diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, etc. may be used alone or in combination of two or more. can be done. Among them, it is preferable to use an aliphatic cyclic structure-containing diisocyanate because a coating film having excellent long-term weather resistance can be formed.

The hydrophilic group-containing polyurethane resin (a1) may optionally have other functional groups in addition to the hydrophilic groups described above. Hydrolyzable silyl groups that can react with (a3), silanol groups, amino groups, imino groups, hydroxyl groups, and the like, among which hydrolyzable silyl groups form coating films with excellent long-term weather resistance. It is preferable because it can be done.

The hydrolyzable silyl group that the polyurethane (a1) having a hydrophilic group may have is a functional group in which a hydrolyzable group is directly bonded to a silicon atom. functional groups represented.

（式中、Ｒ^１はアルキル基、アリール基またはアラルキル基等の１価の有機基を、Ｒ^２はハロゲン原子、アルコキシ基、アシロキシ基、フェノキシ基、アリールオキシ基、メルカプト基、アミノ基、アミド基、アミノオキシ基、イミノオキシ基またはアルケニルオキシ基である。また、ｘは０～２の整数である。）

(wherein R ¹ is a monovalent organic group such as an alkyl group, an aryl group or an aralkyl group; R ² is a halogen atom, an alkoxy group, an acyloxy group, a phenoxy group, an aryloxy group, a mercapto group, an amino group, an amide group, aminooxy group, iminooxy group or alkenyloxy group, and x is an integer of 0 to 2.)

Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, neopentyl group, 1-methylbutyl group, 2-methylbutyl group, hexyl group and isohexyl group. be done.

Examples of the aryl group include phenyl group, naphthyl group and 2-methylphenyl group, and examples of the aralkyl group include benzyl group, diphenylmethyl group and naphthylmethyl group.

Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom and iodine atom.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group.

Examples of the acyloxy group include acetoxy, propanoyloxy, butanoyloxy, phenylacetoxy, acetoacetoxy, and the like. Examples of the aryloxy group include phenyloxy, naphthyloxy, and the like. Examples of groups include an allyloxy group, a 1-propenyloxy group, an isopropenyloxy group, and the like.

Preferably, each R ² is independently an alkoxy group, since elimination components such as R ² OH of the general formula that can be generated by hydrolysis can be easily removed.

In addition, the silanol group that the polyurethane (a1) having a hydrophilic group may have is a functional group in which a hydroxyl group is directly bonded to a silicon atom, and the hydrolyzable silyl group is mainly hydrolyzed. is a functional group generated by

The hydrolyzable silyl groups and silanol groups are preferably present in an amount of 10 to 400 mmol/kg relative to the entire polyurethane (a1) having a hydrophilic group in order to ensure good water dispersion stability of the composite resin. .

Next, the vinyl polymer (a2) constituting the composite resin (A) will be described. The vinyl polymer (a2) is capable of bonding with the hydrophilic group-containing polyurethane (a1) via polysiloxane (a3), which will be described later.

As the vinyl polymer (a2), those having a number average molecular weight of 3,000 to 100,000 are preferably used, and those having a number average molecular weight of 5,000 to 25,000 are preferably used. , which is more preferable for forming a coating film which is excellent in conformability to substrates, durability such as crack resistance, and weather resistance.

As the vinyl polymer (a2), for example, those produced by polymerizing various vinyl monomers in the presence of a polymerization initiator can be used.

The vinyl monomer has a hydrolyzable silyl group from the viewpoint of introducing a functional group capable of reacting with the hydrolyzable silyl group of the polysiloxane (a3) into the vinyl polymer (a2). It is preferable to use a vinyl monomer or a vinyl monomer having a hydroxyl group.

Examples of the vinyl monomer having a hydrolyzable silyl group include 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane or 3-(meth)acryloyloxypropylmethyl Dimethoxysilane and the like can be used, and 3-(meth)acryloyloxypropyltrimethoxysilane is particularly preferred.

Examples of the vinyl monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate, and the like. can do.

As the vinyl monomer, in addition to the vinyl monomer having a hydrolyzable silyl group and the vinyl monomer having a hydroxyl group, other vinyl monomers may be used in combination, if necessary.

Examples of the other vinyl monomers include (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate; N,N-dimethylaminoethyl (meth)acrylate; ) vinyl monomers having a tertiary amino group such as acrylate; vinyl monomers having a secondary amino group such as N-methylaminoethyl (meth)acrylate; vinyl monomers having a primary amino group such as aminomethyl acrylate vinyl monomers having a basic nitrogen atom-containing group such as monomers; fluorine-containing vinyl monomers such as 2,2,2-trifluoroethyl (meth)acrylate; vinyl esters such as vinyl acetate; Vinyl ethers; nitriles of unsaturated carboxylic acids such as (meth)acrylonitrile; vinyl compounds having aromatic rings such as styrene; α-olefins such as isoprene; vinyl monomers having epoxy groups such as glycidyl (meth)acrylate vinyl monomers having an amide group such as (meth)acrylamide; vinyl monomers containing methylolamide groups such as N-methylol(meth)acrylamide and alkoxylated products thereof; 2-aziridinylethyl (meth)acrylate, etc. vinyl monomers having an aziridinyl group; vinyl monomers having isocyanate groups such as (meth)acryloyl isocyanate and/or blocked isocyanate groups; having oxazoline groups such as 2-isopropenyl-2-oxazoline Vinyl monomer; vinyl monomer having cyclopentenyl group such as dicyclopentenyl (meth)acrylate; vinyl monomer having carbonyl group such as acrolein; having acetoacetyl group such as acetoacetoxyethyl (meth)acrylate Vinyl monomer; monomers having a carboxyl group such as (meth)acrylic acid, maleic acid, half esters thereof, or salts thereof can be used singly or in combination of two or more.

Examples of polymerization initiators that can be used in producing the vinyl polymer (a2) include radical polymerization initiators such as persulfates, organic peroxides and hydrogen peroxide, and 4,4′-azobis Azo initiators such as (4-cyanovaleric acid), 2,2′-azobis(2-amidinopropane) dihydrochloride can be used. Moreover, the radical polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent such as ascorbic acid.

Persulfates, which are representative of the polymerization initiator, include, for example, potassium persulfate, sodium persulfate, ammonium persulfate, etc. Specific examples of organic peroxides include, for example, peroxide diacyl peroxides such as benzoyl, lauroyl peroxide, decanoyl peroxide; dialkyl peroxides such as t-butyl cumyl peroxide and dicumyl peroxide; t-butyl peroxylaurate, t-butyl peroxybenzoate, etc. and hydroperoxides such as cumene hydroperoxide, paramenthane hydroperoxide and t-butyl hydroperoxide.

The amount of the polymerization initiator to be used should be an amount that allows the polymerization to proceed smoothly, but should be 10% by mass or less with respect to the total amount of vinyl monomers used in the production of the vinyl polymer (a2). is preferred.

Next, the polysiloxane (a3) constituting the composite resin (A) will be described. The polysiloxane (a3) constitutes a linking portion between the hydrophilic group-containing polyurethane (a1) and the vinyl polymer (a2).

The polysiloxane (a3) has a chain structure composed of silicon atoms and oxygen atoms, and optionally has hydrolyzable silyl groups, silanol groups, and the like. As the polysiloxane (a3), for example, a polysiloxane having one or more structures selected from the group consisting of the following general formulas (I) and (II) and an alkyl group having 1 to 3 carbon atoms Examples thereof include reaction products with condensates of certain alkyltrialkoxysilanes.

（一般式（Ｉ）及び（ＩＩ）中のＲ^１はケイ素原子に結合した炭素原子数が４～１２の有機基、Ｒ^２及びＲ^３は、それぞれ独立にメチル基またはエチル基を表す。）

(In general formulas (I) and (II), R ¹ represents an organic group having 4 to 12 carbon atoms bonded to a silicon atom, and R ² and R ³ each independently represents a methyl group or an ethyl group.)

The hydrolyzable silyl group is an atomic group in which the hydrolyzable group is directly bonded to the silicon atom, and is, for example, general formula (III) exemplified in the explanation of the polyurethane (a1) having a hydrophilic group. can be used.

The hydrolyzable group can form a hydroxyl group under the influence of water, and examples thereof include halogen atoms, alkoxy groups, substituted alkoxy groups, acyloxy groups, phenoxy groups, mercapto groups, amino groups, amido groups, aminooxy groups, iminooxy groups, and alkenyloxy groups, among which alkoxy groups and substituted alkoxy groups are preferred.

The silanol group is an atomic group in which a hydroxyl group is directly bonded to the silicon atom, and is formed when the hydrolyzable silyl group is hydrolyzed.

As the polysiloxane (a3), in addition to the above-described ones, those having an alkyl group such as a methyl group, a phenyl group, or the like can be used as necessary. ) on the silicon atom constituting ), one selected from the group consisting of an aromatic cyclic structure such as a phenyl group, an alkyl group having 1 to 3 carbon atoms, and an alkoxy group having 1 to 3 carbon atoms It is more preferable to use those directly combined with the above in order to maintain good water dispersion stability of the aqueous resin.

As the polysiloxane (a3), for example, those obtained by completely or partially hydrolyzing and condensing a silane compound described below can be used.

Examples of the silane compound include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, iso-butyltrimethoxysilane, cyclohexyltrimethoxysilane, phenyl Organotrialkoxysilanes such as trimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane or 3-(meth)acryloyloxypropyltrimethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldi-n-butoxysilane, diethyldimethoxysilane; Diorganodialkoxysilanes such as silane, diphenyldimethoxysilane, methylcyclohexyldimethoxysilane or methylphenyldimethoxysilane; methyltrichlorosilane, ethyltrichlorosilane, phenyltrichlorosilane, vinyltrichlorosilane, 3-(meth)acryloyloxypropyltrichlorosilane , dimethyldichlorosilane, diethyldichlorosilane or diphenyldichlorosilane, and partial hydrolyzed condensates thereof can be used, among which organotrialkoxysilanes and diorganodialkoxysilanes are used. is preferred. These silane compounds may be used alone or in combination of two or more.

Moreover, the polysiloxane (a3) is preferably formed through a two-step reaction process in the process of producing the composite resin (A). Specifically, the hydrolyzable groups of the vinyl polymer (a2) are reacted with a relatively low-molecular-weight silane compound such as phenyltrimethoxysilane to form a polysiloxane structure, followed by the reaction. A structure composed of polysiloxane (a3) can be formed by reacting the product with a condensate such as methyltrimethoxysilane or ethyltrimethoxysilane. As a result, it is possible to obtain an aqueous resin composition capable of forming a coating film having excellent substrate followability and excellent durability and stain resistance.

Examples of the plasticizer (B) include phthalate esters such as dibutyl phthalate, diheptyl phthalate, di(2-ethylhexyl) phthalate, and butylbenzyl phthalate; aliphatic esters such as butyl oleate and methyl acetylricinoleate. system; dioctyl adipate, dibutyl sebacate, aliphatic dibasic acid esters such as isodecyl succinate, 2-ethylhexyl trimellitate, trimellitate esters such as tridecyl trimellitate, pentaerythritol ester, diethylene glycol di Ether esters such as benzoate, dibutyl carbitol adipate, dibutoxyethoxyethyl adipate, triethylene glycol diacetate, polyethylene glycol di-2-ethylhexanoate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate Benzoates such as benzoate and polyethylene glycol dibenzoate; phosphate esters such as tricresyl phosphate and tributyl phosphate; chlorinated paraffin, alkyldiphenyl, hydrocarbon oil, process oil, epoxidized soybean oil, epoxy stearic acid vinyl-based polymers obtained by polymerizing epoxy-based and vinyl-based monomers such as benzyl by various methods; polyester plasticizers obtained from dihydric alcohols such as propylene glycol and dipropylene glycol; polystyrene compounds such as polystyrene and poly-α-methylstyrene; polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, and polychloroprene be done. Among these, phthalates, trimellitates, ether esters, and benzoates are preferred, and ether esters and benzoates are more preferred, since they further improve low-temperature flexibility. These plasticizers (B) may be used alone or in combination of two or more.

Further, the molecular weight of the plasticizer (B) is preferably in the range of 200 to 2,000, more preferably in the range of 300 to 1,500, since the compatibility with the resin is further improved.

Since the plasticizer (B) provides a coating film with excellent low-temperature flexibility, substrate adhesion, water resistance, weather resistance, and bleed-out resistance, it is , It is important to be in the range of 0.1 to 45 parts by mass, but since the balance between weather resistance and substrate followability is further improved, the range of 1 to 40 parts by mass is more preferable, and 3 to 35 parts by mass. A range of parts is more preferred.

Further, examples of the aqueous medium include water, organic solvents miscible with water, and mixtures thereof. Examples of water-miscible organic solvents include alcohol solvents such as methanol, ethanol, n- and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; polyalkylene glycol solvents such as ethylene glycol, diethylene glycol and propylene glycol; alkyl ether solvents; lactam solvents such as N-methyl-2-pyrrolidone; In the present invention, only water may be used, a mixture of water and an organic solvent miscible with water may be used, or only an organic solvent miscible with water may be used. Water alone or a mixture of water and a water-miscible organic solvent is preferred from the viewpoint of safety and environmental load.

Next, the method for producing the composite resin composition of the present invention will be described. The method for producing the composite resin composition of the present invention mainly comprises a step of producing a composite resin (A), a step of dispersing the composite resin (A) in an aqueous medium, and a step of adding a plasticizer (B). Consists of

First, the steps for producing the composite resin (A) will be described.

The composite resin (A) can be produced, for example, by the following steps (I) to (III).

The step (I) is a step of obtaining an organic solvent solution of the vinyl polymer (a2) by polymerizing the vinyl monomer in an organic solvent in the presence of the polymerization initiator.

Such a reaction is carried out, for example, by sequentially or collectively supplying the vinyl monomers into an organic solvent containing a polymerization initiator, and then conducting the reaction under stirring at a temperature in the range of 20 to 120° C. for about 0.5 to 24 hours. is preferred.

In the step (II), reactive functional groups such as hydrolyzable silyl groups possessed by the vinyl polymer (a2) and hydrolysis of the silane compound possessed by the vinyl polymer (a2) are carried out in an organic solvent solution of the vinyl polymer (a2). A composite resin (A') in which the vinyl polymer (a2) and the polysiloxane (a3) are bonded is produced by proceeding with the reaction with the silyl group or silanol group and the hydrolytic condensation reaction between the silane compounds. This is the step of obtaining an organic solvent solution.

Such a reaction is carried out, for example, by sequentially or collectively supplying the silane compound capable of forming the polysiloxane (a3) into the organic solvent solution of the vinyl polymer (a2) following the step (I), and then , under stirring, at a temperature in the range of 20 to 120° C. for about 0.5 to 24 hours.

The step (II) preferably undergoes a two-stage reaction step. Specifically, a step of reacting a hydrolyzable silyl group or silanol group possessed by the vinyl polymer (a2) with a relatively low-molecular-weight silane compound such as phenyltrimethoxysilane, and then the reactant and a step of reacting with a condensate obtained by condensing methyltrialkoxysilane and ethyltrialkoxysilane in advance, such as methyltrimethoxysilane and ethyltrimethoxysilane. By carrying out the structure formation of the polysiloxane (a3) in two steps as described above, it is possible to obtain an aqueous resin composition that is capable of forming a coating film that is even more excellent in substrate followability and excellent in durability. .

Further, in the step (III), the resin (A′) and the polyurethane (a1) having a hydrophilic group are mixed and hydrolytically condensed to obtain the vinyl polymer (a2) having a hydrophilic group. This is a step of obtaining an organic solvent solution of the composite resin (A) in which the polyurethane (a1) is bonded via the polysiloxane (a3).

The reaction is, for example, the hydrophilicity obtained by reacting the polyisocyanate with the polyol containing the polyol having the hydrophilic group in the organic solvent solution of the composite resin (A) following the step (II). It is preferable to supply the polyurethane (a1) having groups successively or all at once, followed by stirring at a temperature of 20 to 120° C. for about 0.5 to 24 hours.

The organic solvent solution of the composite resin (A) obtained by the above steps (I) to (III) is preferably rendered water-based by the following step (IV).

Step (IV) is, for example, following step (III), neutralizing the hydrophilic groups of the composite resin (A) and dispersing the neutralized product in an aqueous medium.

Neutralization of the hydrophilic group is not necessarily performed, but is preferably performed from the viewpoint of improving the water dispersion stability of the composite resin (A). In particular, when the hydrophilic groups are anionic groups such as carboxyl groups and sulfonic acid groups, all or part of them are neutralized with a basic compound to form carboxylate groups or sulfonate groups. is preferable for further improving the water dispersion stability.

The neutralization can be performed, for example, by sequentially or collectively supplying a basic compound or the like to the organic solvent solution of the composite resin (A) and stirring the mixture.

After the neutralization, an aqueous medium is supplied into an organic solvent solution of the neutralized composite resin (A), and then the organic solvent is removed to produce an aqueous medium dispersion of the composite resin (A). can do.

Removal of the organic solvent can be carried out, for example, by distillation.

The aqueous resin composition of the present invention contains the composite resin (A) dispersed or dissolved in an aqueous medium and further contains a plasticizer (B). A method of mixing the plasticizer (B) after dispersing or dissolving, a method of mixing the composite resin (A) and the plasticizer (B) and then mixing them with an aqueous medium, manufacturing the composite resin (A) In this case, a method of including a plasticizer (B) in advance in the system and mixing them with an aqueous medium can be used.

The water-based resin composition of the present invention suppresses a rapid increase in viscosity during production, and from the viewpoint of improving the productivity of the water-based resin composition, the ease of coating, the drying property, etc. It preferably has a nonvolatile content of 70% by mass, more preferably in the range of 30 to 60% by mass.

If necessary, a curing agent may be used in combination with the aqueous resin composition of the present invention.

As the curing agent, a compound having a functional group that reacts with the hydrophilic group or silanol group of the composite resin (A) can be used.

Specific examples of the curing agent include compounds having silanol groups and/or hydrolyzable silyl groups, polyepoxy compounds, polyoxazoline compounds, polycarbodiimide compounds, polyisocyanate compounds, and the like. In particular, when using a composite resin having a carboxyl group or a carboxylate group, a compound having an epoxy group and a silanol group and/or a hydrolyzable silyl group, a polyepoxy compound, a polyoxazoline compound, a polycarbodiimide compound It is preferable to set it as the combination which uses.

Examples of the compound having a silanol group and/or a hydrolyzable silyl group include, for example, those similar to the silane compounds exemplified as usable in the production of the composite resin, and 3-glycidoxypropyltri methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, etc. , and hydrolytic condensates thereof.

Examples of the polyepoxy compound include polyglycidyl ethers having a structure derived from an aliphatic or alicyclic polyol such as ethylene glycol, hexanediol, neopentyl glycol, trimethylolpropane, pentaerythritol, sorbitol, and hydrogenated bisphenol A. polyglycidyl ethers of aromatic diols such as bisphenol A, bisphenol S and bisphenol F; polyglycidyl ethers of polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; tris(2-hydroxyethyl)isocyanurate - polyglycidyl ethers of polyglycidyl ethers; polyglycidyl esters of aliphatic or aromatic polycarboxylic acids such as adipic acid, butanetetracarboxylic acid, phthalic acid and terephthalic acid; hydrocarbon dienes such as cyclooctadiene and vinylcyclohexene and alicyclic polyepoxy compounds such as bis(3,4-epoxycyclohexylmethyl)adipate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate.

Examples of the polyoxazoline compounds include 2,2′-p-phenylene-bis(1,3-oxazoline), 2,2′-tetramethylene-bis(1,3-oxazoline), 2,2′-octa Methylene-bis(2-oxazoline), 2-isopropenyl-1,3-oxazoline, or polymers thereof can be used.

Examples of the polyisocyanate compounds include aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane-4,4'-diisocyanate; meta-xylylene diisocyanate, α,α,α',α'-tetramethyl-meta-xyl Aralkyl diisocyanates such as diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, 1,3-bisisocyanatomethylcyclohexane, 2-methyl-1,3-diisocyanatocyclohexane, 2-methyl-1,5-diisocyanatocyclohexane , isophorone diisocyanate, and the like can be used.

As the polyisocyanate compound, various prepolymers having an isocyanate group, prepolymers having an isocyanurate ring, polyisocyanates having a biuret structure, and vinyl monomers having an isocyanate group can also be used.

The isocyanate group of the polyisocyanate compound as a curing agent may be blocked by a conventionally known blocking agent such as methanol, if necessary.

The curing agent is preferably used in a solid content range of 0.1 to 50 parts by mass, and is used in a range of 0.5 to 30 parts by mass, for example, with respect to 100 parts by mass of the composite resin (A). is more preferable, and it is particularly preferable to use it in the range of 1 to 20 parts by mass.

Further, when the composite resin (A) has a carboxyl group as a hydrophilic group, the curing agent has an epoxy group, cyclo Equivalents of reactive functional groups such as carbonate groups, hydroxyl groups, oxazoline groups, carbodiimide groups and hydrazino groups are preferably in the range of 0.2 to 5.0 equivalents, more preferably in the range of 0.5 to 3.0 equivalents. It is more preferably within the range of 0.7 to 2.0 equivalents, particularly preferably within the range.

In addition, the aqueous resin composition of the present invention may contain a curing catalyst, if necessary.

Examples of the curing catalyst include lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium methylate, tetraisopropyl titanate, tetra-n-butyl titanate, tin octylate, lead octylate, cobalt octylate, and zinc octylate. , calcium octylate, zinc naphthenate, cobalt naphthenate, di-n-butyltin diacetate, di-n-butyltin dioctoate, di-n-butyltin dilaurate, di-n-butyltin maleate, p-toluenesulfone Acids, trichloroacetic acid, phosphoric acid, monoalkylphosphoric acids, dialkylphosphoric acids, monoalkylphosphorous acids, dialkylphosphorous acids and the like can be used.

The aqueous resin composition of the present invention can also contain a thermosetting resin, if necessary. Such thermosetting resins include vinyl resins, polyester resins, polyurethane resins, epoxy resins, epoxy ester resins, acrylic resins, phenolic resins, fluororesins, petroleum resins, ketone resins, silicone resins, or modified resins thereof. mentioned.

Various inorganic particles such as clay minerals, metals, metal oxides and glass can be used in the aqueous resin composition of the present invention, if necessary. Metal types include gold, silver, copper, platinum, titanium, zinc, nickel, aluminum, iron, silicon, germanium, antimony, and metal oxides thereof.

The water-based resin composition of the present invention may optionally contain photocatalytic compounds, inorganic pigments, organic pigments, extender pigments, waxes, surfactants, stabilizers, flow modifiers, dyes, leveling agents, rheology control agents, and ultraviolet rays. Various additives such as absorbents and antioxidants can be used.

INDUSTRIAL APPLICABILITY The water-based resin composition of the present invention can form a coating film having excellent low-temperature flexibility and weather resistance, and thus can be used for various applications such as coating agents and adhesives. Among them, the aqueous resin composition of the present invention is preferably used as a coating agent because it can form a coating film excellent in low-temperature flexibility, stain resistance, durability and weather resistance, and a coating agent for forming a top layer. It is more preferable to use it as a coating agent for forming a primer layer.

Examples of substrates on which the coating agent can be applied to form a coating film include inorganic substrates, plastic substrates, metal substrates, cloth, paper, and wood substrates.

In addition, the coating agent of the present invention has stain resistance, durability, weather resistance and low-temperature flexibility, and the plasticizer (B) contained in the coating agent combines the composite resin (A) with the pigment or functional filler. It can be suitably used as a high-performance coating agent because it increases the affinity for and exhibits excellent dispersibility.

Moreover, since the coating agent of the present invention has extremely excellent adhesion to plastic substrates, it can be suitably used as a coating agent for coating the surface of plastic substrates.

As the plastic base material, polycarbonate base material, polyester base material, acrylonitrile-butadiene-styrene base material, poly A plastic substrate selected from the group consisting of acrylic substrates, polystyrene substrates, polyurethane substrates, epoxy resin substrates, polyvinyl chloride substrates and polyamide substrates can be used.

The various substrates described above may be coated in advance, but since the coating agent of the present invention has excellent adhesion to plastic substrates, etc., surface treatment such as coating is applied in advance. It can be used without any problem even if the base material does not have

Further, the base material may be plate-like, spherical, film-like, or sheet-like. In addition, since the coating agent of the present invention is particularly excellent in flexibility, it is suitable for film-like or sheet-like substrates that are prone to deformation or expansion and contraction due to the effects of external force, temperature, etc., and substrates that have fine unevenness on the surface. can be preferably used.

The coating agent of the present invention, for example, by directly applying it to the surface of the substrate, then drying and curing, has excellent coating film appearance, weather resistance, stain resistance, flexibility, etc. after an exposure test. A coating film can be formed.

A coated article can be obtained by coating the coating agent on various substrates as described above and curing the coating. At that time, (1) the coating agent is directly applied to the substrate, (2) the base coat is applied in advance to the substrate, and then the coating agent is applied as the top coat, (3) to the substrate. A coated object can be obtained by a coating method such as applying the above-mentioned coating agent as an undercoat and then coating another topcoat to form a coating film.

Examples of methods for applying the coating agent of the present invention include brush coating, roller coating, spray coating, dip coating, flow coater coating, roll coater coating, and electrodeposition coating.

In addition, when obtaining a coated object having a coating film made of the coating agent by the coating method of (2) or (3), conventionally known acrylic resin-based paints and polyester resins are used as undercoat paints and topcoat paints. system paints, alkyd resin-based paints, epoxy resin-based paints, fatty acid-modified epoxy resin-based paints, silicone resin-based paints, polyurethane resin-based paints, and the like can be used.

As the method of drying and curing, a method of curing at room temperature for about 1 to 10 days may be used. A method of heating to a certain degree is preferred. In addition, when using a plastic substrate that easily deforms or discolors at relatively high temperatures, curing is preferably performed at a relatively low temperature of about 30 to 100°C.

The film thickness of the coating film formed using the coating agent of the present invention can be 0.5 to 1,000 μm depending on the use of the substrate.

Examples of articles having a coating film formed using the coating agent of the present invention by the method described above include housings of home appliances such as televisions, refrigerators, washing machines, and air conditioners; personal computers, smartphones, and mobile phones. , housings for electronic equipment such as digital cameras and game machines; housings for OA equipment such as printers and facsimiles; Interior and exterior materials for buildings such as exterior walls, roofs, glass, and veneers; membrane structures; civil engineering materials such as soundproof walls and drains; zinc plating used for home appliances, industrial machinery, automobile parts, etc. Metal members such as steel plates, plated steel plates such as aluminum-zinc alloy steel plates, aluminum plates, aluminum alloy plates, electromagnetic steel plates, copper plates, and stainless steel plates can also be used. Furthermore, since the coating agent of the present invention can form a coating film having excellent conformability to substrates, various functional films constituting flexible solar cells or polarizing plates of liquid crystal displays can also be used.

Next, the present invention will be specifically described with reference to examples and comparative examples.

(Synthesis Example 1: Production of condensate (a3′-1) of methyltrimethoxysilane)
A reactor equipped with a stirrer, a thermometer, a dropping funnel, a condenser and a nitrogen gas inlet was charged with 1,421 parts by mass of methyltrimethoxysilane (hereinafter abbreviated as "MTMS") and heated to 60°C. I warmed up. Then, a mixture of 0.17 parts by mass of iso-propyl acid phosphate ("A-3" manufactured by Sakai Chemical Co., Ltd.) and 207 parts by mass of deionized water was added dropwise to the reaction vessel over 5 minutes, and then heated to 80°C. The mixture was stirred at the temperature for 4 hours to cause a hydrolytic condensation reaction.

The condensate obtained by the above hydrolytic condensation reaction is subjected to a temperature of 40 to 60 ° C. and a reduced pressure of 40 to 1.3 kPa (the reduced pressure condition at the start of distillation of methanol is 40 kPa, and finally becomes 1.3 kPa. The same shall apply hereinafter) to remove the methanol and water produced in the reaction process, thereby containing the condensate (a3′-1) of MTMS with a number average molecular weight of 1,000. 1,000 parts by mass of a liquid (70% by mass of active ingredient) was obtained.

The effective ingredient is the value obtained by dividing the theoretical yield (parts by mass) when all the methoxy groups of the silane monomer such as MTMS are condensed by the actual yield (parts by mass) after the condensation reaction [methoxy of the silane monomer] Theoretical yield (parts by mass) when all groups are subjected to condensation reaction/Actual yield after condensation reaction (parts by mass)].

(Synthesis Example 2: Production of composite resin intermediate (A'-1))
Propylene glycol monopropyl ether (hereinafter abbreviated as "PnP") 125 parts by mass, phenyltrimethoxysilane (hereinafter "PTMS") and 102 parts by mass of dimethyldimethoxysilane (hereinafter abbreviated as "DMDMS") were charged, and the temperature was raised to 80°C.
Next, at the same temperature, 38 parts by mass of methyl methacrylate (hereinafter abbreviated as "MMA"), 24 parts by mass of butyl methacrylate (hereinafter abbreviated as "BMA"), and butyl acrylate (hereinafter abbreviated as "BA") were ) 36 parts by mass, acrylic acid (hereinafter abbreviated as “AA”) 24 parts by mass, 3-methacryloxypropyltrimethoxysilane (hereinafter abbreviated as “MPTS”) 4 parts by mass, PnP 54 parts by mass and 6 parts by mass of tert-butylperoxy-2-ethylhexanoate (hereinafter abbreviated as “TBPEH”) was added dropwise into the reaction vessel over 4 hours, and then further at the same temperature. By reacting for 2 hours, an organic solvent solution of an acrylic polymer (a2-1) having a number average molecular weight of 10,200 and having a carboxyl group and a hydrolyzable silyl group was obtained.
Next, a mixture of 2.7 parts by mass of iso-propyl acid phosphate ("A-3" manufactured by Sakai Chemical Co., Ltd.) and 76 parts by mass of deionized water was added dropwise over 5 minutes, and the mixture was further stirred at the same temperature for 1 hour. A composite resin intermediate in which the hydrolyzable silyl groups of the acrylic polymer (a2-1) and the hydrolyzable silyl groups and silanol groups of the PTMS- and DMDMS-derived polysiloxanes are bonded by hydrolytic condensation reaction A liquid containing body (A''-1) was obtained.
Next, 291 parts by mass of a liquid containing the composite resin intermediate (A''-1) and a liquid containing the condensate (a3'-1) of MTMS obtained in Synthesis Example 1 (active ingredient: 70% by mass) Further, 49 parts by mass of deionized water is added and stirred at the same temperature for 16 hours to carry out a hydrolytic condensation reaction to obtain a condensate of the composite resin intermediate (A''-1) and MTMS 1,000 parts by mass of a liquid (50% by mass of non-volatile matter) containing the composite resin intermediate (A'-1) to which (a3'-1) was bound was obtained.

(Synthesis Example 3: Production of composite resin (A-1))
Into a reaction vessel equipped with a stirrer, thermometer, dropping funnel, cooling tube and nitrogen gas inlet, 158 parts by mass of polytetramethylene glycol having a number average molecular weight of 2,000 (manufactured by Mitsubishi Chemical Corporation "PTMG-2000"), isophorone. 66 parts by mass of diisocyanate (hereinafter abbreviated as “IPDI”) was charged, heated to 100° C., and reacted at the same temperature for 1 hour.
Next, the temperature is lowered to 80 ° C., dimethylolpropionic acid (hereinafter abbreviated as “DMPA”) 13 parts by mass, neopentyl glycol (hereinafter abbreviated as “NPG”) 5 parts by mass, and methyl ethyl ketone (hereinafter abbreviated as “NPG”) , abbreviated as "MEK".) was put into the reaction vessel and further reacted at 80°C for 5 hours.
Next, the temperature is lowered to 50° C., and 30 parts by mass of 3-aminopropyltriethoxysilane (hereinafter abbreviated as “APTES”) and 285 parts by mass of isopropyl alcohol (hereinafter abbreviated as “IPA”) are added to the above An organic solvent solution of polyurethane (a1-1) having a number average molecular weight of 7,400 and having a carboxyl group and a hydrolyzable silyl group was produced by putting it into a reaction vessel and reacting it.
Next, the total amount of the organic solvent solution of the polyurethane (a1-1) and 158 parts by mass of the liquid (A'-1) containing the composite resin intermediate are mixed, and hydrolytically condensed under stirring at 80° C. for 1 hour. By reacting, a liquid containing a composite resin in which the hydrolyzable silyl group of the polyurethane (a1-1) and the hydrolyzable silyl group of the composite resin intermediate (A'-1) are bonded is obtained. rice field. Next, this liquid is mixed with 10 parts by mass of triethylamine (hereinafter abbreviated as "TEA") to obtain a neutralized product obtained by neutralizing the carboxyl groups in the composite resin, and then the neutralized product is A mixture of 610 parts by mass of deionized water is distilled under a reduced pressure of 300 to 10 mmHg under a condition of 40 to 60 ° C. for 4 hours, and the generated methanol, organic solvent and water are removed. 1,000 parts by mass of an aqueous dispersion of 35% by mass composite resin (A-1) was obtained.

(Synthesis Example 4: Production of composite resin (A-2))
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, cooling tube and nitrogen gas inlet, polytetramethylene glycol having a number average molecular weight of 2,000 ("PTMG-2000" manufactured by Mitsubishi Chemical Corporation) 122 parts by mass, IPDI 51 parts by mass was charged, the temperature was raised to 100° C., and the reaction was carried out at the same temperature for 1 hour.
Then, the temperature was lowered to 80° C., 10 parts by mass of DMPA, 4 parts by mass of NPG, and 94 parts by mass of MEK were charged into the reaction vessel, and then reacted at 80° C. for 5 hours.
Next, the temperature is lowered to 50° C., and 23 parts by mass of APTES and 221 parts by mass of IPA are charged into the reaction vessel and reacted, whereby the number average molecular weight having a carboxyl group and a hydrolyzable silyl group is 7,500. to obtain an organic solvent solution of polyurethane (a1-2).
Next, the total amount of the organic solvent solution of the polyurethane (a1-2) and 279 parts by mass of the liquid containing the composite resin intermediate (A'-1) obtained in Synthesis Example 2 were mixed and stirred at 80°C. Contains a composite resin in which a hydrolyzable silyl group of the polyurethane (a1-2) and a hydrolyzable silyl group of the composite resin intermediate (A'-1) are bonded by hydrolytic condensation reaction for 1 hour. I got a liquid that Next, this liquid was mixed with 14 parts by mass of TEA to obtain a neutralized product obtained by neutralizing the carboxyl groups in the composite resin, and then the neutralized product was mixed with 610 parts by mass of deionized water. , and distilled under the same conditions as in Synthesis Example 3 to obtain 1,000 parts by mass of an aqueous dispersion of composite resin (A-2) having a nonvolatile content of 35% by mass.

(Synthesis Example 5: Production of composite resin (A-3))
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, cooling tube and nitrogen gas inlet, polytetramethylene glycol having a number average molecular weight of 2,000 (PTMG-2000 manufactured by Mitsubishi Chemical Corporation) 61 parts by mass, IPDI 26 mass The mixture was heated to 100° C. and reacted at the same temperature for 1 hour.

Next, the temperature was lowered to 80° C., 5 parts by mass of DMPA, 2 parts by mass of NPG, and 47 parts by mass of MEK were charged into the reaction vessel, followed by further reaction at 80° C. for 5 hours.
Next, the temperature is lowered to 50° C., and 12 parts by mass of APTES and 110 parts by mass of IPA are charged into the reaction vessel and reacted, whereby the number average molecular weight having a carboxyl group and a hydrolyzable silyl group is 7,500. to obtain an organic solvent solution of polyurethane (a1-3).
Next, the total amount of the organic solvent solution of the polyurethane (a1-3) and 489 parts by mass of the liquid containing the composite resin intermediate (A'-1) obtained in Synthesis Example 2 were mixed and stirred at 80°C. A composite resin in which the hydrolyzable silyl groups of the polyurethane (a1-3) and the hydrolyzable silyl groups of the composite resin intermediate (A'-1) are bonded is produced by hydrolytic condensation reaction for 1 hour. A containing liquid was obtained. Next, by mixing this liquid with 16 parts by mass of TEA to obtain a neutralized product in which the carboxyl groups in the composite resin are neutralized, the neutralized product is mixed with 560 parts by mass of deionized water. was distilled under the same conditions as in Synthesis Example 3 to obtain 1,000 parts by mass of an aqueous dispersion of composite resin (A-3) having a nonvolatile content of 35% by mass.

(Synthesis Example 6: Production of composite resin (A-4))
A polycarbonate polyol having a 1,6-hexanediol skeleton and a number average molecular weight of 2,000 (Ube Industries, Ltd., "UH-200 ”) 123 parts by mass and 50 parts by mass of IPDI were charged, heated to 100° C., and reacted at the same temperature for 1 hour.
Then, the temperature was lowered to 80° C., 10 parts by mass of DMPA, 4 parts by mass of NPG, and 94 parts by mass of MEK were charged into the reaction vessel, and then reacted at 80° C. for 5 hours.
Next, the temperature is lowered to 50° C., and 23 parts by mass of APTES and 221 parts by mass of IPA are charged into the reaction vessel and reacted to obtain a compound having a carboxyl group and a hydrolyzable silyl group and a number average molecular weight of 7,300. An organic solvent solution of polyurethane (a1-4) was obtained.
Next, the total amount of the organic solvent solution of the polyurethane (a1-4) and 279 parts by mass of the liquid containing the composite resin intermediate (A'-1) obtained in Synthesis Example 2 were mixed and stirred at 80°C for 1 hour. It contains a composite resin in which the hydrolyzable silyl group of the polyurethane (a1-4) and the hydrolyzable silyl group of the composite resin intermediate (A'-1) are bonded by hydrolytic condensation reaction over time. I got a liquid that Next, this liquid was mixed with 14 parts by mass of TEA to obtain a neutralized product in which the carboxyl groups in the composite resin were neutralized, and then the neutralized product was mixed with 610 parts by mass of deionized water. The mixture was distilled under the same conditions as in Synthesis Example 3 to obtain 1,000 parts by mass of an aqueous dispersion of composite resin (A-4) having a nonvolatile content of 35% by mass.

(Synthesis Example 7: Production of composite resin (A-5))
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, cooling tube and nitrogen gas inlet, 122 parts by mass of polytetramethylene glycol (PTMG-2000 manufactured by Mitsubishi Chemical Corporation) with a number average molecular weight of 2,000 and 51 parts by mass of IPDI The mixture was heated to 100° C. and reacted at the same temperature for 1 hour.

Next, the temperature was lowered to 80° C., 10 parts by mass of DMPA, 4 parts by mass of NPG, and 94 parts by mass of MEK were charged into the reaction vessel, followed by further reaction at 80° C. for 5 hours.
Then, the temperature is lowered to 50 ° C., 23 parts by mass of APTES, 221 parts by mass of IPA, and a plasticizer (manufactured by ADEKA Co., Ltd. "ADEKA CIZER RS-700", a polyether ester plasticizer; hereinafter, plasticizer (B-1 ).) By charging 50 parts by mass into the reaction vessel and reacting, polyurethane (a1-5) having a number average molecular weight of 7,500 having a carboxyl group and a hydrolyzable silyl group and a plasticizer An organic solvent solution containing (B-1) was obtained.
Next, the total amount of this organic solvent solution and 279 parts by mass of the liquid containing the composite resin intermediate (A'-1) obtained in Synthesis Example 2 are mixed and hydrolytically condensed under stirring at 80° C. for 1 hour. Thus, a composite resin and a plasticizer (B-1) in which the hydrolyzable silyl group of the polyurethane (a1-5) and the hydrolyzable silyl group of the composite resin intermediate (A'-1) are bonded A liquid containing Next, by mixing this liquid with 14 parts by mass of TEA to obtain a neutralized product in which the carboxyl groups in the composite resin are neutralized, the neutralized product is mixed with 560 parts by mass of deionized water. was distilled under the same conditions as in Synthesis Example 3 to obtain 1,000 parts by mass of an aqueous dispersion containing the plasticizer (B-1) and the composite resin (A-5) and having a non-volatile content of 35% by mass. rice field.

(Synthesis Example 8: Production of aqueous resin composition (8))
In a reaction vessel equipped with a stirrer, thermometer, dropping funnel, cooling tube and nitrogen gas inlet, 122 parts by mass of polytetramethylene glycol (PTMG-2000 manufactured by Mitsubishi Chemical Corporation) with a number average molecular weight of 2,000 and 51 parts by mass of IPDI The mixture was heated to 100° C. and reacted at the same temperature for 1 hour.

Next, the temperature was lowered to 80° C., 10 parts by mass of DMPA, 4 parts by mass of NPG, and 94 parts by mass of MEK were charged into the reaction vessel, followed by further reaction at 80° C. for 5 hours.
Next, the temperature is lowered to 50° C., and 23 parts by mass of APTES and 221 parts by mass of IPA are charged into the reaction vessel and reacted, whereby the number average molecular weight having a carboxyl group and a hydrolyzable silyl group is 7,500. to obtain an organic solvent solution of polyurethane (a1-6).
Next, the total amount of the polyurethane (a1-6) organic solvent solution and 279 parts by mass of the liquid containing the composite resin intermediate (A'-1) obtained in Synthesis Example 2 were mixed and stirred at 80° C. for 1 hour. It contains a composite resin in which the hydrolyzable silyl group of the polyurethane (a1-5) and the hydrolyzable silyl group of the composite resin intermediate (A'-1) are bonded by hydrolytic condensation reaction over time. I got a liquid that Next, by mixing this liquid with 14 parts by mass of TEA, a neutralized product obtained by neutralizing the carboxyl groups in the composite resin is obtained. and 560 parts by mass of deionized water were distilled under the same conditions as in Synthesis Example 3 to obtain a nonvolatile content containing the plasticizer (B-1) and the composite resin (A-6) of 35. 1,000 parts by weight of an aqueous dispersion of % by weight was obtained.

(Example 1: Production and evaluation of aqueous resin composition (1))
100 parts by mass of the aqueous dispersion of the composite resin (A-1) obtained in Synthesis Example 3, a plasticizer (manufactured by ADEKA Co., Ltd. "Adekasizer RS-700", a polyether ester plasticizer; hereinafter, plasticizer (B -1).) 5 parts by mass and 3.5 parts by mass of 3-glycidoxypropyltrimethoxysilane (hereinafter abbreviated as “GPTMS”) are uniformly mixed to form an aqueous resin composition (1). ).

(Example 2: Production and evaluation of aqueous resin composition (2))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, 5 parts by mass of the plasticizer (B-1), and 3.5 parts by mass of GPTMS are uniformly mixed to form an aqueous resin composition. (2) was obtained.

(Example 3: Production and evaluation of aqueous resin composition (3))
100 parts by mass of the aqueous dispersion of the composite resin (A-3) obtained in Synthesis Example 5, 5 parts by mass of the plasticizer (B-1), and 4.0 parts by mass of GPTMS are uniformly mixed to form an aqueous resin composition. (3) was obtained.

(Example 4: Production and evaluation of aqueous resin composition (4))
100 parts by mass of the aqueous dispersion of the composite resin (A-4) obtained in Synthesis Example 6, 5 parts by mass of the plasticizer (B-1), and 3.8 parts by mass of GPTMS are uniformly mixed to form an aqueous resin composition. (4) was obtained.

(Example 5: Production and evaluation of aqueous resin composition (5))
100 parts by mass of the aqueous dispersion containing the plasticizer (B-1) and the composite resin (A-5) obtained in Synthesis Example 7 and 3.5 parts by mass of GPTMS were uniformly mixed to form an aqueous resin composition ( 5) was obtained.

(Example 6: Production and evaluation of aqueous resin composition (6))
100 parts by mass of the aqueous dispersion containing the plasticizer (B-1) and the composite resin (A-6) obtained in Synthesis Example 6 and 3.5 parts by mass of GPTMS were uniformly mixed to form an aqueous resin composition ( 5) was obtained.

(Example 7: Production and evaluation of aqueous resin composition (7))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, a plasticizer ("Monocizer W-262" manufactured by DIC Corporation, an ether ester plasticizer; hereinafter referred to as "Plasticizer (B -2).) 10 parts by mass and 3.5 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (7).

(Example 8: Production and evaluation of aqueous resin composition (8))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, a plasticizer ("Monocizer PB-3A" manufactured by DIC Corporation, a benzoic acid ester plasticizer; hereinafter referred to as "plasticizer ( B-3)”) and 3.5 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (8).

(Example 9: Production and evaluation of aqueous resin composition (9))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, a plasticizer (manufactured by DIC Corporation "Monocizer DOA", dioctyl adipate; hereinafter referred to as "plasticizer (B-4)" ) and 4.0 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (9).

(Example 10: Production and evaluation of aqueous resin composition (10))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, a plasticizer (manufactured by DIC Corporation "Monocizer DBP", dibutyl phthalate; hereinafter, "plasticizer (B-5)" ) and 3.8 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (10).

(Example 11: Production and evaluation of aqueous resin composition (11))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, a plasticizer ("ADEKA CIZER C-8" manufactured by ADEKA Co., Ltd., a trimellitate ester plasticizer; hereinafter referred to as "plasticizer (B-6)”) and 3.5 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (11).

[Preparation of pigment dispersion]
47 parts by mass of water in a dedicated pot of a sand mill (Grind to Hegman 8), 12 parts by mass of "DISPERBYK-190" manufactured by BYK-Chemie Japan Co., Ltd., 140 parts by mass of "Ti-Pure R-706" manufactured by Chemours Co., Ltd., Potters "GB201" manufactured by Ballotini Co., Ltd. was charged and kneaded for 30 minutes at 25°C and 3000 rpm to obtain a pigment dispersion.

(Example 12: Production and evaluation of aqueous resin composition (12))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and a plasticizer (manufactured by DIC Corporation "Monocizer W-260", ether Ester-based plasticizer; hereinafter abbreviated as "plasticizer (B-7)." 5 parts by mass were uniformly mixed to obtain an aqueous resin composition (12).

(Example 13: Production and evaluation of aqueous resin composition (13))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and 10 parts by mass of the plasticizer (B-7) are uniformly mixed, An aqueous resin composition (13) was obtained.

(Example 14: Production and evaluation of aqueous resin composition (14))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and 20 parts by mass of the plasticizer (B-7) are uniformly mixed, An aqueous resin composition (14) was obtained.

(Example 15: Production and evaluation of aqueous resin composition (15))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and 40 parts by mass of the plasticizer (B-7) are uniformly mixed, An aqueous resin composition (15) was obtained.

(Comparative Example 1: Production and evaluation of aqueous resin composition (R1))
28 parts by mass of the pigment dispersion obtained above and 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4 were uniformly mixed to obtain an aqueous resin composition (R1).

(Comparative Example 2: Production and evaluation of aqueous resin composition (R2))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and 10 parts by mass of diethylene glycol monobutyl ether are uniformly mixed to form an aqueous resin composition. (R2) was obtained.

(Comparative Example 3: Production and evaluation of aqueous resin composition (R3))
28 parts by mass of the pigment dispersion obtained above, 100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, and 60 parts by mass of the plasticizer (B-7) are uniformly mixed, An aqueous resin composition (R3) was obtained.

(Comparative Example 4: Production and evaluation of aqueous resin composition (R4))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4 and 3.5 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (R4).

(Comparative Example 5: Production and evaluation of aqueous resin composition (R5))
100 parts by mass of the aqueous dispersion of the composite resin (A-2) obtained in Synthesis Example 4, 10 parts by mass of diethylene glycol monobutyl ether, and 3.5 parts by mass of GPTMS were uniformly mixed to obtain an aqueous resin composition (R5). Obtained.

(Comparative Example 6: Production and evaluation of aqueous resin composition (R6))
100 parts by weight of acrylic silicone emulsion ("Boncoat SA-6030" manufactured by DIC Corporation, non-volatile content 50% by weight; hereinafter abbreviated as comparative aqueous resin (1)), and 10 parts by weight of plasticizer (B-7) were uniformly mixed to obtain an aqueous resin composition (R6).

(Comparative Example 7: Production and evaluation of aqueous resin composition (R7))
Water-based polyurethane resin ("Hydran WLS-201" manufactured by DIC Corporation, non-volatile content 35% by mass; hereinafter abbreviated as comparative water-based resin (2)) 100 parts by mass, and plasticizer (B-7) 10 parts by mass were uniformly mixed to obtain an aqueous resin composition (R7).

[Method for preparing cured coating film for evaluation]
After coating an acrylic-urethane white paint on a chromate-treated aluminum plate manufactured by Engineering Test Service Co., Ltd. and then polishing it with water, the water-based resin composition obtained above is dried to a film thickness of 30 μm. and dried for one week in an environment of 25° C. to obtain a cured coating film for evaluation.

[Evaluation of Coating Appearance]
The cured coating film obtained above was visually observed, and the appearance of the coating film was evaluated according to the following criteria.
◯: No cracks were observed.
Δ: Some cracks are observed.
x: Occurrence of cracks is observed.

[Evaluation of low temperature flexibility]
As evaluation of low-temperature flexibility, coating film elongation at low temperature was measured.
(Method for measuring coating elongation)
The water-based resin composition obtained above was coated on a substrate made of a polypropylene film so that the film thickness was 200 μm, dried in an environment of 140° C. for 5 minutes, and then further dried in an environment of 25° C. After drying for 24 hours, the film peeled off from the substrate was used as a test coating film (10 mm x 70 mm).
The elongation of the test coating film was measured using Shimadzu Corporation "Autograph AGS-1kNG (distance between chucks: 20 mm, pulling speed: 300 mm / min, measurement atmosphere: -10 ° C.)". It was evaluated based on the elongation rate with respect to the coating film before the test. It is practically preferable that the elongation is 20% or more.

[Evaluation of pigment dispersibility]
The specular gloss reflectance of the cured coating film for evaluation obtained above was measured using a micro-tri-gloss manufactured by BYK Corporation.
A larger value of this gloss retention indicates better dispersibility.
○: 60° specular gloss reflectance of 70 or more △: 60° specular gloss reflectance of 50 or more and less than 70 ×: 60° specular gloss reflectance of less than 50

[Evaluation of adhesion]
The cured coating film for evaluation obtained above was measured based on the JIS K-5600 cross-cut test method. On the cured coating film, cuts with a width of 1 mm were made with a cutter so that the number of grids was 100, cellophane tape was attached so as to cover all the grids, and the grids that remained attached were quickly peeled off. was counted and evaluated according to the following criteria.
○: No peeling.
Δ: The peeling area is 1 to 64% of the total grid area.
x: The peeling area is 65% or more of the total grid area.

[Evaluation of water resistance]
The cured coating film for evaluation obtained above was immersed in water at 25° C. for 7 days, and then immediately after being removed from the water, the appearance was visually observed and evaluated according to the following criteria 1. However, the aqueous resin compositions (12) to (15) and (R1) to (R3) were evaluated according to Criterion 2 because the coating film was white before immersion.
(Standard 1)
◯: Whitening, cracks, and blisters are not observed.
Δ: Whitening is partially observed, but cracks and blisters are not observed.
x: Whitening is observed on the whole. Alternatively, cracks and blisters are observed.
(Standard 2)
○: Gloss retention rate is 80% or more △: Gloss retention rate is 40% or more and less than 80% ×: Gloss retention rate is less than 40% The specular gloss reflectance before and after the water resistance test is measured by BYK Co., Ltd. Micro-Tri- It was measured using gloss, and the gloss retention rate was obtained based on the following formula. A higher value of this gloss retention indicates better water resistance.
Gloss retention rate (%) = 100 x (specular reflectance of coating film after water resistance test) / (specular reflectance of coating film before water resistance test)

[Evaluation of weather resistance (appearance)]
For the cured coating film for evaluation obtained above, a due panel light weather meter (manufactured by Suga Test Instruments Co., Ltd., when irradiated with light: 30 W / m2, 70 ° C.; when wet: humidity of 90% or more, 50 ° C., light irradiation / After 1,000 hours of exposure (wet cycle = 8 hours/4 hours), the coating film was visually observed and the appearance of the coating film was evaluated according to the following criteria.
◯: No cracks were observed.
Δ: Some cracks are observed.
x: Occurrence of cracks is observed.

[Evaluation of weather resistance (gloss retention)]
The specular reflectance (gloss value) (%) of the cured coating film for evaluation immediately after preparation and the cured coating film are measured with a due panel light weather meter (manufactured by Suga Test Instruments Co., Ltd., when irradiated with light: 30 W / m2, 70 ° C. When wet: Specular reflectance (gloss value) (%) of the coating film after exposure for 1,000 hours at a humidity of 90% or more, 50 ° C., light irradiation / wet cycle = 8 hours / 4 hours, before exposure Retention rate (gloss retention rate: %) for the specular reflectance (gloss value) of the cured coating film [(100 × specular reflectance of the coating film after exposure) / (mirror reflectance of the cured coating film before exposure)] evaluated with A higher retention value indicates better weather resistance. Specular reflectance was measured using Micro-Tri-Gloss manufactured by BYK Corporation.

[Evaluation of bleed-out resistance]
The cured coating film for evaluation obtained above was allowed to stand in an atmosphere of 70° C. and a relative humidity of 95% for one month, and then the surface condition of the cured coating film was evaluated for the presence or absence of exudation of the plasticizer by touching with a finger. bottom. Evaluation criteria are as follows.
○: No exudation.
Δ: Slight bleeding.
x: Remarkable oozing.

Tables 1 to 3 show formulations and evaluation results of aqueous resin compositions (1) to (15) of Examples 1 to 15.

Table 4 shows the composition and evaluation results of the aqueous resin compositions (R1) to (R7) of Comparative Examples 1 to 7.

From the aqueous resin compositions of the present invention of Examples 1 to 15, cured coatings excellent in various physical properties such as coating film appearance, low-temperature flexibility, pigment dispersibility, adhesion, water resistance, weather resistance, and bleed-out resistance It was confirmed that a membrane was obtained.

Comparative Examples 1 and 4, which are examples containing no plasticizer (B), were confirmed to be inferior in coating film appearance, low-temperature flexibility, pigment dispersibility, and water resistance.

Comparative Examples 2 and 5 are examples in which diethylene glycol monobutyl ether was used instead of the plasticizer (B).

Comparative Example 3 is an example in which the content of the plasticizer (B) with respect to 100 parts by mass of the composite resin (A) is more than 45 parts by mass, which is the upper limit of the present invention. It was confirmed that the bleed-out resistance was inferior.

Comparative Example 6 is an example using an acrylic silicon resin as the resin, but it was confirmed that the low-temperature flexibility and water resistance were inferior.

Comparative Example 7 is an example using a water-based urethane resin as the resin, but it was confirmed that the water resistance, weather resistance, and bleed-out resistance were inferior.

Claims (5)

An aqueous resin composition containing a composite resin (A) in which a polyurethane (a1) having a hydrophilic group and a vinyl polymer (a2) are bonded via a polysiloxane (a3), a plasticizer (B), and an aqueous medium. wherein the bond between the hydrophilic group-containing polyurethane (a1) and the polysiloxane (a3) is such that the hydrolyzable silyl group and/or silanol group of the polyurethane (a1) and the polysiloxane (a3) is a condensation bond with a hydrolyzable silyl group and/or a silanol group, and the bond between the vinyl polymer (a2) and the polysiloxane (a3) is a hydrolyzable bond of the vinyl polymer (a2) A structure derived from the polysiloxane (a3) in the composite resin (A), which is a condensation bond between a silyl group and/or a silanol group and a hydrolyzable silyl group and/or a silanol group possessed by the polysiloxane (a3) is in the range of 15 to 55% by mass, and the content of the plasticizer (B) with respect to 100 parts by mass of the composite resin (A) is in the range of 0.1 to 45 parts by mass. Aqueous resin composition. The water-based resin according to claim 1, wherein the mass ratio [(a2)/(a1)] of the polyurethane (a1) having a hydrophilic group and the vinyl polymer (a2) is in the range of 20/1 to 1/20. Composition. The polysiloxane (a3) is a polysiloxane having one or more structures selected from the group consisting of the following general formulas (I) and (II), and an alkyl trisiloxane having 1 to 3 carbon atoms in the alkyl group. 3. The water-based resin composition according to claim 1, which is a reaction product with a condensate of alkoxysilane.

(In general formulas (I) and (II), R ¹ represents an organic group having 4 to 12 carbon atoms bonded to a silicon atom, and R ² and R ³ each independently represents a methyl group or an ethyl group.) A coating agent comprising the aqueous resin composition according to any one of claims 1 to 3. An article comprising a cured coating film of the coating agent according to claim 4.