JP2020019853A - Aqueous composite resin, and coating agent for exterior - Google Patents

Abstract

To provide an aqueous composite resin excellent in adhesiveness to various substrates, followability, scratch resistance, weather resistance, stain resistance, and a coating agent for exterior.SOLUTION: There is provided an aqueous composite resin (I) in which an acryl urethane composite resin by polymerizing an ethylenic unsaturated monomer (E) containing an alkoxysilyl group-containing ethylenic unsaturated monomer (e-1) using both terminal mercapto group-containing urethane resin (C-2) by reacting a compound (D) represented by the general formula (1) with an urethane polymer (C-1) by reacting polyol (A) and polyisocyanate (B) as a chain transfer agent, and polysiloxane (H) by hydrolysis condensing a silane compound (G) are bound, and organotrialkoxysilane (g-1) and/or diorganodialkoxysilane (g-2) having one of a linear or alicyclic alkyl group having 3 to 10 carbon atoms, and a phenyl group are contained with 55 to 100 wt.% as total amount.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous composite resin and an exterior coating agent.

In recent years, from the viewpoint of reducing environmental load and ensuring safety and health of workers, switching from solvent-based to water-based has been rapidly progressing in various coating fields. As an exterior coating agent for imparting durability to a base material, a fluororesin or silicone resin having excellent weather resistance is used as a binder, and the study of making them water-based is also being actively conducted. On the other hand, there is an increasing demand for the expansion of the target base material for exterior coating agents every year, and future non-polarity such as plasticization of mobility materials for the purpose of energy saving and resource conservation by weight reduction, filmization of building materials, etc. The response to plastic substrates is urgent.

Patent Literature 1 discloses an aqueous dispersion of a fluorinated copolymer and a coating agent for exterior containing the same. These fluorinated copolymers are more excellent in weather resistance than general-purpose acrylic resins and acrylic / urethane composite resins, and can impart high durability. However, adhesion to various non-polar substrates is remarkably poor, and there is a problem in stain resistance.

Patent Literature 2 discloses an exterior coating agent containing an organic-inorganic composite aqueous dispersion in which polysiloxane is stabilized using an acrylic resin having a siloxane bond as a protective colloid. This organic-inorganic composite aqueous dispersion exhibits excellent weather resistance at the level of a fluororesin, and also has a stain resistance function. However, this coating agent also has poor adhesion to a non-polar substrate and cannot be said to have sufficient followability. Therefore, the coating film is easily cracked.

In Patent Document 3, in order to improve the adhesion and followability to a non-polar film substrate, a urethane resin having a polysiloxane bond and an acrylic resin are used in combination to form a protective colloid, and an organic-inorganic material in which the polysiloxane is stabilized A composite resin and an exterior coating agent containing the same are disclosed. However, even with the organic-inorganic composite resin prepared by this composite method, it is difficult to achieve both satisfactory scratch resistance, substrate adhesion, and conformability. In particular, it cannot cope with the adhesiveness to an olefin-based non-polar substrate.

JP-A-2002-179871 JP-A-11-116683 JP 2010-001457 A

It is an object of the present invention to provide a water-based composite resin excellent in adhesion, followability, scratch resistance, weather resistance, and stain resistance to various substrates including non-polar plastic substrates, and a coating agent for exterior use.

（一般式（１）中、Ｘは−ＯＨ、−ＮＨ_２、−ＮＨＲ_１、および−ＳＨからなる群より選ばれる少なくとも一種であり、Ｒ_１はアルキル基である。
Ｒはアルキレン基、アリーレン基、およびアルキレンオキサイド基からなる群より選ばれる少なくとも一種の２価の基である。） The present invention provides both ends of a urethane prepolymer (C-1) obtained by reacting a polyol (A) with a polyisocyanate (B) and a compound (D) represented by the general formula (1). It is obtained by polymerizing an ethylenically unsaturated monomer (E) containing an alkoxysilyl group-containing ethylenically unsaturated monomer (e-1) using a mercapto group-containing urethane resin (C-2) as a chain transfer agent. Acrylic / urethane composite resin (F) is bonded to polysiloxane (H) obtained by hydrolytic condensation of silane compound (G),
An organotrialkoxysilane (g-1) having a linear or alicyclic alkyl group having 3 to 10 carbon atoms or a phenyl group in 100% by weight of the silane compound (G), and / or diorgano The present invention relates to an aqueous composite resin (I) containing a dialkoxysilane (g-2) in a total amount of 55 to 100% by weight.
General formula (1)

(In the general formula (1), X is at least one selected from the group consisting of —OH, —NH ₂ , —NHR ₁ , and —SH, and R ₁ is an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group. )

The present invention relates to the aqueous composite resin (I), wherein the compound (D) represented by the general formula (1) is aminoalkanethiol.

The present invention provides the aqueous composite resin, wherein at least one of the polyether polyol (a-1) and the polycarbonate polyol (a-3) is contained in an amount of 70 to 100% by weight based on 100% by weight of the polyol (A). (I).

The present invention provides the aqueous composite, wherein the content of the ethylenically unsaturated monomer (E) is in the range of 50 to 200 parts by weight based on 100 parts by weight of the urethane urea resin (C-2) having a mercapto group at both ends. It relates to resin (I).

The present invention relates to the aqueous composite resin (I), wherein the content of the silane compound (G) is in the range of 35 to 120 parts by weight based on 100 parts by weight of the acrylic / urethane composite resin (F).

The present invention relates to the aqueous composite resin (I) described above, wherein the average particle diameter is in a range of 30 to 180 nm.

The present invention relates to an exterior coating agent containing the aqueous composite resin (I).

The present invention further relates to the exterior coating agent containing a curing agent (J) having a reactive group.

The exterior coating agent of the present invention has good storage stability and exhibits excellent adhesion to various substrates including non-polar substrates, conformability, scratch resistance, weather resistance, and stain resistance. Therefore, it can be used arbitrarily for plastics base materials (films and molded products) requiring high durability, in addition to mobility-related members such as building materials and automobiles, energy-related members such as backsheets for solar cells, and the like.

First, the acrylic / urethane composite resin (F) used in the present invention will be described. The acrylic / urethane composite resin (F) is obtained by adding a compound (D) represented by the general formula (1) to a urethane prepolymer (C-1) obtained by reacting a polyol (A) with a polyisocyanate (B). It can be obtained by synthesizing a urethane urea resin (C-2) containing a mercapto group at both ends by reacting and polymerizing an ethylenically unsaturated monomer (E) using it as a chain transfer agent.
Specifically, the method for producing the acrylic / urethane composite resin (F) of the present invention will be described. First, a polyol (A) and a polyisocyanate (B) are charged into a reaction tank, and a catalyst is added to cause a reaction to synthesize a urethane prepolymer (C-1) having both ends of isocyanate groups. Subsequently, the compound (D) represented by the general formula (1) is added to the urethane prepolymer (C-1) and reacted. Thereby, a urethane resin (C-2) containing a mercapto group at both ends can be synthesized. Further, by adding an ethylenically unsaturated monomer (E) and a solvent and adding a radical initiator under a nitrogen atmosphere, a chain transfer reaction occurs, and both ends of the urethane resin (C-2) containing a mercapto group at both ends are obtained. Acrylic resin is grafted from the end. The ethylenically unsaturated monomer (E) contains an alkoxysilyl group-containing ethylenically unsaturated monomer (e-1), and the acrylic resin skeleton serves as a linking site with the polysiloxane component. An alkoxylyl group is introduced.

<Polyol (A)>
Representative examples of the polyol (A) used for the urethane prepolymer (C-1) include polyether polyol (a-1), polyester polyol (a-2), polycarbonate polyol (a-3), and polyolefin. System polyol (a-4), castor oil polyol and the like. These polyols may be used alone or in combination of two or more.

  Among the polyols mentioned above, at least either polyether polyol (a-1) or polycarbonate polyol (a-3) from the viewpoint of chemical stability such as hydrolysis resistance and good compatibility with an acrylic skeleton. It is preferable to contain one or more kinds, and it is more preferable to contain the polycarbonate polyol (a-3) from the viewpoints of imparting even more excellent scratch resistance and weather resistance.

Furthermore, based on 100% by weight of the polyol (A), at least one of the polyether polyol (a-1) and the polycarbonate polyol (a-3) is contained in a range of 70 to 100% by weight in total. Is preferred. When the content is within the above range, the hydrolysis resistance of the organic-inorganic composite resin (I) is improved. Therefore, the storage stability of the exterior coating agent, the adhesion of the coating film to the substrate, the followability, the scratch resistance, the weather resistance, and the like are further improved.

Examples of the polyether polyol (a-1) include polymers or copolymers such as methylene oxide, ethylene oxide, propylene oxide, and tetrahydrofuran, specifically, polyethylene glycol, polypropylene glycol, and poly (ethylene / propylene) glycol And polytetramethylene glycol. In addition, hexanediol, methylhexanediol, heptanediol, octanediol, and polyether polyols obtained by condensation of a mixture of these are exemplified.

  Examples of the polyester polyol (a-2) include a polyester polyol obtained by a condensation reaction between a polyol component and a dibasic acid component. Among the polyols, diols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 3,3′-diol. Methylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, Examples of the polyol having three or more hydroxyl groups include cyclohexanediol and bisphenol A, and glycerin, trimethylolpropane, and pentaerythritol. Terephthalic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, hydrogenated dimer acid, phthalic acid anhydride, isophthalic acid, aliphatic or aromatic dibasic acids such as trimellitic acid, and anhydrides thereof. Further, polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as lactones such as ε-caprolactone, poly (β-methyl-γ-valerolactone) and polyvalerolactone are also exemplified.

  Examples of the polycarbonate polyol (a-3) include those obtained by reacting a polyol with a carbonate compound such as dialkyl carbonate, alkylene carbonate, or diaryl carbonate. As the polyol constituting the polycarbonate polyol, the polyol exemplified above as the constituent component of the polyester polyol can be used. Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate, examples of the alkylene carbonate include ethylene carbonate, and examples of the diaryl carbonate include diphenyl carbonate.

Examples of the polyolefin polyol (a-4) include hydroxyl-containing polybutadiene, hydrogenated hydroxyl-containing polybutadiene, hydroxyl-containing polyisoprene, hydrogenated hydroxyl-containing polyisoprene, hydroxyl-containing chlorinated polypropylene, and hydroxyl-containing chlorinated polyethylene. .

Castor oil polyol is a biomass polyol made from plant-derived castor oil.

In addition to the above, a low molecular diol can be used in combination for the purpose of adjusting the urethane bond concentration or introducing various functional groups. As the low molecular weight diol, a diol having a molecular weight of 500 or less is preferable, for example,
Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, octanediol, 2-butyl-2- Ethyl-1,3-propanediol, 1,4-butylene diol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-butanetriol, pentaerythritol, sorbitol, N, N-bis ( Dimethylolalkanoic acids such as 2-hydroxypropyl) aniline, dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, and dihydroxypropionic acid , Dihydroxy And benzoic acid.

<Polyisocyanate (B)>
Examples of the polyisocyanate (B) to be reacted with the polyol (A) include aromatic, aliphatic and alicyclic polyisocyanates. These may be used alone or in combination of two or more.

  As the aromatic polyisocyanate, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, lysine diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 1,5-naphthalene Examples include diisocyanate and 1,5-tetrahydronaphthalenediisocyanate.

  Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, 1,4-cyclohexylene diisocyanate, dicyclohexylmethane 4,4′-diisocyanate, and the like.

In the reaction for obtaining the urethane prepolymer (C-1), a catalyst can be used. As a catalyst that can be used, a known metal catalyst or amine catalyst can be used. Examples of the metal catalyst include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexoate), lead 2-ethylhexoate, 2-ethylhexyl titanate, titanium ethyl acetate, and 2-ethylhexoate. Iron, 2-ethylhexoate cobalt, zinc naphthenate, cobalt naphthenate, tetra-n-butyltin and the like. Examples of the amine catalyst include tertiary amines such as tetramethylbutanediamine. These catalysts are used in the range of 0.001 to 1 mol% based on the polymer polyol.

The reaction for obtaining the urethane prepolymer (C-1) is preferably performed at 50 to 150 ° C. for 2 to 12 hours. The end point of the reaction can be determined by measuring the amount of residual NCO by titration.

As a solvent that can be used for obtaining the urethane prepolymer (C-1), any solvent can be used as long as it does not react with an isocyanate group. It is preferable to use a solvent which is azeotropic and easy to remove. It is also possible to carry out the reaction without solvent and to dilute the solvent later. Preferred solvents include ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone;
Ester solvents such as ethyl acetate, propyl acetate and butyl acetate;
Glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; and the like.

（一般式（１）中、Ｘは−ＯＨ、−ＮＨ_２、−ＮＨＲ_１、および−ＳＨからなる群より選ばれる少なくとも一種であり、Ｒ_１はアルキル基である。
Ｒはアルキレン基、アリーレン基、およびアルキレンオキサイド基からなる群より選ばれる少なくとも一種の２価の基である。 <Compound (D) represented by Formula (1)>
By reacting the above-mentioned urethane prepolymer (C-1) with the mercapto group-containing compound (D) represented by the general formula (1), a urethane resin (C-2) having a mercapto group at both terminals is obtained.

General formula (1)

(In the general formula (1), X is at least one selected from the group consisting of —OH, —NH ₂ , —NHR ₁ , and —SH, and R ₁ is an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group.

Examples of the alkyl group for R ₁ include an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and a dodecyl group. Alkyl groups of formulas 1 to 6 are preferred.
Examples of the alkylene group among R include an alkylene group having 1 to 12 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and a dodecylene group. Alkylene groups of numbers 1 to 6 are preferred.
Examples of the arylene group include a phenylene group, and examples of the alkylene oxide group include ethylene oxide, propylene oxide, and butylene oxide. R is preferably an alkylene group or a phenylene group.

As the compound (D) represented by the general formula (1), for example,
Hydroxyalkanethiols such as 2-hydroxyethanethiol, 3-hydroxypropyl-1-thiol, 1-hydroxypropyl-2-thiol, 4-hydroxy-1-butanethiol;
Dithiols such as 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, and 1,6-hexanedithiol;
Aminoalkanethiols such as 2-aminoethanethiol, 3-aminopropyl-1-thiol, 1-aminopropyl-2-thiol, 4-amino-1-butanethiol;
Aminobenzenethiols such as 2-aminothiophenol, 3-aminothiophenol and 4-aminothiophenol;
Is mentioned.

Among the compounds of the general formula (1) (D), a high reactivity, from the viewpoint of forming a urea bond, X is -NH ₂ or -NHR _1, using the amino alkane thiols R is an alkylene group Is preferred. By introducing a urea bond, the cohesive force of the resin coating film is increased, and the adhesion to a non-polar substrate, abrasion resistance, and weather resistance are improved. Further, by charging so that the number of moles of the isocyanate group is excessive with respect to the number of moles of the amino group, the remaining isocyanate group reacts with the mercapto group to extend the chain, thereby increasing the urethane prepolymer (C-1). Molecular weight. At this time, a urea bond is introduced into the urethane resin in addition to both ends, so that the abrasion resistance and the substrate adhesion are improved. In addition, since the unreacted compound (D) is also reduced, the odor of the resin coating film is significantly improved. The compound (D) represented by the general formula (1) is preferably reacted so as to be 0.60 to 0.90 mol with respect to 1 mol of the isocyanate group of the urethane prepolymer (C-1).

The urethane resin (C-2) containing a mercapto group at both ends preferably has an acid value of less than 5 mgKOH / g, and more preferably does not contain an anionic functional group. When the content is less than 5 mgKOH / g, the polysiloxane skeleton in the core portion is further stabilized, and a composite resin aqueous dispersion having a small particle size and a narrow distribution can be obtained. Therefore, the film forming property of the exterior coating agent is improved, and the abrasion resistance and weather resistance are further improved. Further, the adhesion of the organic-inorganic composite resin to the interface of the base material is improved, and the followability of the resin coating film to the base material is further improved. In the present specification, the acid value is the number of mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin, and can be determined by the method described in Examples.

As the solvent that can be used for obtaining the urethane resin (C-2) containing a mercapto group at both ends, any solvent can be used as long as it can dissolve the raw materials and does not react with the isocyanate group. In consideration of the above, a solvent which is azeotropic with water and easily removed is preferable. Preferred solvents include ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate, propyl acetate and butyl acetate; glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. Is mentioned.

<Ethylenically unsaturated monomer (E)>
The acrylic / urethane composite resin (F) can be obtained by graft-polymerizing the ethylenically unsaturated monomer (E) using the urethane resin (C-2) having a mercapto group at both ends as a chain transfer agent.

For the purpose of chemically bonding the polysiloxane (H) and the acrylic / urethane composite resin (F), the ethylenically unsaturated monomer (E) is prepared by converting an alkoxysilyl group-containing ethylenically unsaturated monomer (e-1). Including. By introducing a polysiloxane bond into the acrylic / urethane composite resin (F), the dispersing power of the polysiloxane as a core component is further improved. Further, the dried coating film of the organic-inorganic composite resin becomes transparent and tough. Therefore, the storage stability of the coating agent, adhesion to various substrates, followability, scratch resistance, weather resistance, and stain resistance are further improved.

Examples of the alkoxysilyl group-containing ethylenically unsaturated monomer (e-1) include:
γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxy Propyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane , Vinyltributoxysilane, vinylmethyldimethoxysilane, p-styryltrimethoxysilane and the like.

In the acrylic / urethane composite resin (F) used in the present invention, the acrylic skeleton functions as a hydrophilic group. Therefore, the ethylenically unsaturated monomer (E) preferably contains the hydrophilic group-containing ethylenically unsaturated monomer (e-2). Depending on the functional group of the ethylenically unsaturated monomer used, an anionic, cationic or nonionic hydrophilic group can be appropriately introduced. Examples of the anionic hydrophilic group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Examples of the cationic hydrophilic group include an amino group. Examples of the nonionic hydrophilic group include a polyethylene oxide group and an amide group. Groups, hydroxyl groups and the like.

As the hydrophilic group-containing ethylenically unsaturated monomer (e-2), for example,
As those having an anionic hydrophilic group,
Maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid or their alkyl or alkenyl monoesters, hexahydrophthalic acid β- (meth) acryloxyethyl monoester, succinic acid β- (meth) acryloxy Carboxyl group-containing ethylenically unsaturated monomers such as ethyl monoester, acrylic acid, methacrylic acid, crotonic acid, and cinnamic acid; styrene sulfonic acid, sodium styrene sulfonate, ammonium styrene sulfonate, lithium styrene sulfonate, 2- Acrylamide 2-methylpropanesulfonic acid, 2-acrylamide sodium 2-methylpropanesulfonate, methallylsulfonic acid, sodium methallylsulfonate, allylsulfonic acid, sodium allylsulfonate, ammonium allylsulfonate Sulfonic acid group-containing ethylenically unsaturated monomers such as, vinyl sulfonic acid, allyloxybenzene sulfonic acid, sodium allyloxybenzene sulfonate, and ammonium allyloxybenzene sulfonate;
Basic phosphoric acid-containing ethylene such as 2-methacryloyloxyethyl acid phosphate, 2-acryloyloxyethyl acid phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, and dibutyl-2-acryloyloxysilethyl phosphate Unsaturated monomer;
As those having a cationic hydrophilic group,
Amino group-containing ethylenically unsaturated monomers such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methylethylaminoethyl (meth) acrylate, dimethylaminostyrene and diethylaminostyrene;
As having a nonionic hydrophilic group,
Polyethylene glycol mono (meth) acrylate (manufactured by NOF Corporation, Blenmer PE-90, 200, 350, 350G, AE-90, 200, 400, etc.) Polyethylene glycol / polypropylene glycol mono (meth) acrylate (manufactured by NOF Corporation, Blenmer Ethylenically unsaturated monomers containing a polyethylene oxide group, such as 50 PEP-300, 70 PEP-350, etc., and methoxypolyethylene glycol mono (meth) acrylate (manufactured by NOF Corporation, Blemmer PME-400, 550, 1000, 4000, etc.);
(Meth) acrylamide, N-methoxymethyl- (meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl -(Meth) acrylamide, N, N-di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmeth Acrylamide, N, N-di (propoxymethyl) acrylamide, N-butoxymethyl-N- (propoxymethyl) methacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) meth Acrylic N, N-di (pentoxymethyl) acrylamide, N-methoxymethyl-N- (pentoxymethyl) methacrylamide, N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, N, N-dimethyl Amide group-containing ethylenically unsaturated monomers such as acrylamide, N, N-diethylacrylamide, diacetone (meth) acrylamide;
Hydroxyl-containing ethylenically unsaturated monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, and allyl alcohol;
And the like, but are not particularly limited thereto. These can be used alone or in combination of two or more.

Among the hydrophilic group-containing ethylenically unsaturated monomers (e-2), carboxyl group-containing ethylenically unsaturated monomers are used in view of the development of weather resistance of the exterior coating film and the crosslinking with the curing agent (J). It is more preferable to use

Other ethylenically unsaturated monomers (e-) copolymerizable with the alkoxysilyl group-containing ethylenically unsaturated monomer (e-1) and the hydrophilic group-containing ethylenically unsaturated monomer (e-2) 3) For example,
Styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol acrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene Aromatic-containing ethylenically unsaturated monomers such as glycol acrylate, phenoxytetraethylene glycol methacrylate, phenoxyhexaethylene glycol acrylate, phenoxyhexaethylene glycol methacrylate, phenyl acrylate, phenyl methacrylate;
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, heptyl (meth) acrylate, hexyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate Linear or branched alkyl group-containing ethylenically unsaturated monomers such as
An alicyclic alkyl group-containing ethylenically unsaturated monomer such as cyclohexyl (meth) acrylate or isobonyl (meth) acrylate;
Fluorinated alkyl group-containing ethylenically unsaturated monomers such as trifluoroethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate;
Keto group-containing ethylenically unsaturated monomers such as 2-acetoacetoxyethyl (meth) acrylate;
Allyl (meth) acrylate, vinyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, 1,4-butanediol di (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Glycerin dimethacrylate, dimethylol tricyclodecane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( Data) acrylate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, ethylenically unsaturated monomer having two or more ethylenically unsaturated groups such as diallyl maleate;
Epoxy group-containing ethylenically unsaturated monomers such as glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate;
And the like, but are not particularly limited thereto. These can be used alone or in combination of two or more.

The glass transition temperature (Tg) of the acrylic resin portion obtained by polymerizing the above-mentioned ethylenically unsaturated monomer (E) is preferably in the range of 35 to 100 ° C. When the glass transition temperature is in the range of 30 to 100 ° C., the coating film strength is improved, and a coating agent excellent in abrasion resistance, substrate adhesion, and followability can be obtained.

The above-mentioned glass transition temperature refers to a theoretical value calculated from the following FOX equation. However, the ethylenically unsaturated monomer (e-1) is excluded.
<FOX type>
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wi / Tgi + ... Wn / Tgn
[In the FOX formula, the glass transition temperature of the homopolymer of each monomer constituting the polymer composed of n kinds of monomers is Tgi (K), the mass fraction of each monomer is Wi, and (W1 + W2 +... Wi + ... Wn = 1). ]

The amount of the ethylenically unsaturated monomer (E) is preferably from 50 to 200 parts by weight based on 100 parts by weight of the urethane resin having both ends mercapto groups (C-2). When it is in the above range, the particle diameter of the aqueous composite resin (I) becomes small, and the dispersion stability is improved. In addition, the film-forming properties are promoted, and the adhesion, abrasion resistance, and weather resistance of the coating agent to the nonpolar substrate are further improved.

As the radical initiator used for grafting the acrylic moiety, known oil-soluble polymerization initiators can be used, for example, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxide. Organic peroxides such as oxy (2-ethylhexanoate), tert-butylperoxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide;
2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1 Azobis compounds such as' -azobis-cyclohexane-1-carbonitrile can be mentioned.

The radical initiator is preferably used in a range of 0.1 to 0.5 part by weight based on 100% by weight of the ethylenically unsaturated monomer (E). When used in the range of 0.1 to 0.5 parts by weight, the acrylic moiety is effectively grafted to the urethane moiety.

Next, a process for obtaining the organic-inorganic composite resin (I) in which the above-mentioned acrylic / urethane composite resin (F) and polysiloxane (H) are bonded will be described. Polysiloxane (H) has a chain structure composed of silicon and oxygen atoms, and is obtained by subjecting silane compound (G) to hydrolysis / condensation reaction in the presence of acrylic / urethane composite resin (F). Can be. A specific manufacturing method will be described. First, a silane compound (G) is added to the acrylic / urethane composite resin (F) solution obtained above. After uniform mixing, an acidic catalyst and ion-exchanged water are added to hydrolyze the silane compound, followed by a slight condensation reaction. Further, a basic neutralizing agent and ion-exchanged water are added, and the phase is changed to an aqueous phase while removing the solvent under reduced pressure at low temperature. After removing the solvent, by finally heating to accelerate the condensation reaction, an aqueous dispersion of the target composite resin can be obtained.

The silane compound (G) is a linear or alicyclic alkyl group having 3 to 10 carbon atoms, an organotrialkoxysilane (g-1) having a functional group of any one of a phenyl group, and / or an organodialkoxysilane (g). g-2), and the total amount is in the range of 55 to 100% by weight based on 100% by weight of the silane compound (G). By containing in the above range, the acrylic / urethane composite resin (F) and the polysiloxane (H) interact appropriately, and the organic-inorganic composite resin (I) having a small particle size, a narrow distribution, and excellent dispersion stability. ) Can be obtained. Further, the compatibility between the acrylic / urethane composite resin (F) skeleton and the polysiloxane (H) skeleton during film formation is improved, and a more transparent and tough coating film can be obtained. Thereby, the storage stability of the exterior coating agent, the adhesion to the substrate, the followability, the scratch resistance, and the weather resistance are also improved.

Examples of the organotrialkoxysilane (g-1) having a functional group of any of a linear or alicyclic alkyl group having 3 to 10 carbon atoms and a phenyl group include, for example,
n-propyltrimethoxysilane, n-propyltriethoxysilane,
iso-butyltrimethoxysilane, iso-butyltriethoxysilane,
Hexyltrimethoxysilane, hexyltriethoxysilane,
Cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,
Phenyltrimethoxysilane, phenyltriethoxysilane,
n-octyltrimethoxysilane, n-octyltriethoxysilane,
n-decyltrimethoxysilane, n-decyltriethoxysilane,
And the like.

Among them, phenyltrimethoxysilane or phenyltriethoxysilane is preferable. These are preferably contained in the range of 55 to 100% by weight, more preferably in the range of 65 to 100% by weight, based on 100% by weight of the silane compound (G).

As the diorganodialkoxysilane (g-2), for example,
Dimethyldimethoxysilane, dimethyldiethoxysilane,
Dimethyldi-n-butoxysilane, diethyldimethoxysilane,
Diphenyldimethoxysilane, methylcyclohexyldimethoxysilane,
Methylphenyldimethoxysilane and the like can be mentioned. These silane compounds (G) may be used alone or in combination of two or more.

Other silane compounds (G) usable in the present invention include, for example,
Methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-butoxysilane,
n-dodecyltrimethoxysilane, n-dodecyltriethoxysilane,
Organotrialkoxysilanes such as vinyltrimethoxysilane or 3- (meth) acryloyloxypropyltrimethoxysilane;
And the like.

As the silane compound (G), an oligomer obtained by partially hydrolyzing and condensing an alkoxysilyl group of the above silane compound can also be used. These may be synthesized or commercially available products may be used.
Commercially available partial hydrolysis condensates include, for example,
Shin-Etsu Silicone KC-89S KR-515 KR-500 X-40-9225 X-40-9246 X-40-9250 KR-401N X-40-9227 KR-510 KR-9218 KR-213 and the like. .

The content of the silane compound (G) constituting the polysiloxane (H) is preferably in the range of 35 to 120 parts by weight based on 100 parts by weight of the acrylic / urethane composite resin (F). When the content is within the above range, a more stable aqueous dispersion of the organic-inorganic composite resin is obtained, and storage stability is improved. In addition, the effect of introducing polysiloxane is appropriately exhibited, and an outer coating agent excellent in substrate adhesion, followability, scratch resistance, weather resistance and stain resistance can be obtained.

The reaction solvent used in the hydrolysis and condensation reaction preferably contains an alcohol solvent such as ethanol, isopropyl alcohol, n-propanol, and isobutanol n-butanol from the viewpoint of stability during the reaction. These alcohol solvents include ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate, propyl acetate and butyl acetate; glycol ester solvents such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate. ;
And any other organic solvent may be mixed.

When the organic-inorganic composite resin (I) is phase-inverted to be aqueous, examples of the basic compound that can be used as a neutralizing agent include:
Ammonia, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine, N-methylmorpholine, 2-amino-2- Examples thereof include amines such as ethyl-1-propanol and pyridine, and inorganic alkalis such as sodium hydroxide and potassium hydroxide.
Among them, in view of dispersion stability in an aqueous medium, film forming property during drying, and coating film properties after drying, it is more preferable to use amines as the neutralizing agent, and to use dimethylethanolamine. It is suitable.

The organic-inorganic composite resin (I) preferably has an acid value in the range of 15 to 45 mgKOH / g. When the content is within the above range, the dispersion stability of the organic-inorganic resin (I) is improved, and the storage stability of the exterior coating agent is improved. In addition, the adhesion of the dried coating film to the non-polar substrate, scratch resistance, and weather resistance are further improved. In the present specification, the acid value is the number of mg of potassium hydroxide required to neutralize an acidic component contained in 1 g of the resin.

The average particle diameter of the organic-inorganic composite resin (I) is preferably in the range of 30 to 180 nm. When the content is within the above range, the dispersion stability of the organic-inorganic resin (I) and the good film-forming property are compatible with each other, and a coating agent excellent in substrate adhesion, followability, scratch resistance and weather resistance can be obtained. it can.

The organic-inorganic composite resin (I) of the present invention can be suitably used for various coating agents, particularly for exterior coating agents used for automobile members and building materials. In the long term, it can be applied to next-generation energy-related components such as next-generation mobility and living space-related components, solar cells and various sensors. In addition to the above-mentioned organic-inorganic composite resin (I), necessary additives such as a hydrophilic solvent, a curing agent, a light stabilizer and an ultraviolet absorber may be added and used.

The organic-inorganic composite resin (I) preferably contains 15 to 45% by weight, and more preferably 25 to 40% by weight in terms of solid content, based on 100% by weight of the exterior coating agent. When the amount of the aqueous composite resin (I) is within the above range, the functions of the exterior coating agent for exhibiting abrasion resistance and weather resistance are more effectively exhibited.

  The exterior coating agent of the present invention may be used as a clear coating film, or may be used in combination with various pigments as long as the function is not impaired.

As the pigment, achromatic pigments such as titanium oxide, calcium carbonate, and carbon black, and chromatic organic pigments can be used.

As a specific example of titanium oxide, “Taipec CR-50, 50-2, 57, 80, 90, 93, 95, 953, 97, 60, 60-2, 63, 67, 58, 58-” manufactured by Ishihara Sangyo Co., Ltd. 2, 85 "," Taipaque R-820, 830, 930, 550, 630, 680, 670, 580, 780, 780-2, 850, 855 "," Taipaque A-100, 220 "," Taipaque W-10 "," Taipaque " PF-740, 744 "," TTO-55 (A), 55 (B), 55 (C), 55 (D), 55 (S), 55 (N), 51 (A), 51 (C) ", TTO-S-1, 2 "," TTO-M-1, 2 ", Teita's" Titanics JR-301, 403, 405, 600A, 605, 600E, 603, 805, 806, 701, 800, 808 " "Titanic EN-1, C, 3, 4, 5 ", and the like manufactured by Du Pont" Taipyua R-900,902,960,706,931 ".

Further, the coating agent for exterior of the present invention can be used in combination with a hydrophilic solvent for the purpose of controlling the coating property and drying property on the base material and promoting the film forming property of the organic-inorganic composite resin (I). .

The hydrophilic solvent is preferably contained in the range of 0.5 to 10% by weight based on 100% by weight of the exterior coating agent. When the content is in the above range, the effect of adding the hydrophilic solvent can be obtained without adverse effects such as the remaining of the hydrophilic solvent in the coating film. Therefore, it becomes an exterior coating agent excellent in adhesion to various substrates, followability, scratch resistance, and weather resistance.

As the hydrophilic solvent that can be used for the exterior coating agent of the present invention, for example,
Monohydric alcohol solvents such as ethanol, 1-propanol (n-propanol), 2-propanol (isopropyl alcohol), 1-butanol, 2-methyl-1-propanol, 2-butanol and 2-methyl-2-propanol;
Ethylene glycol, 1,3-propanediol, propylene glycol, 1,2-butanediol, 1,4-butanediol, pentylene glycol, 1,2-hexanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol , Glycol-based solvents such as tetraethylene glycol;
Ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, triethylene glycol monoisopropyl Ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, triethylene glycol monoisobutyl ether, ethylene glycol monohexyl ether , Diethylene glycol monohexyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, glycol ethers such as tripropylene glycol monomethyl ether solvent;
Lactam solvents such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 2-pyrrolidone and ε-caprolactam;
Amide solvents such as formamide, N-methylformamide, N, N-dimethylformamide, Idemitsu Equamide M-100 and Equamide B-100 are preferred, and monohydric alcohol solvents and glycol ether solvents are preferred.
These can be used alone or in combination of two or more.

For the purpose of dispersing various additives and improving the binding function of the coating agent, the exterior coating agent of the present invention can be used in combination with other aqueous resins as long as the performance is not adversely affected. Examples of the aqueous resin that can be used in combination include (meth) acrylic acid-alkyl (meth) acrylate copolymer, styrene- (meth) acrylic acid-alkyl (meth) acrylate copolymer, and styrene- (meth) acrylic acid Copolymer, maleic acid-alkyl (meth) acrylate copolymer, styrene-maleic acid copolymer, styrene-maleic acid-alkyl (meth) acrylate copolymer, styrene-maleic half ester Coalescing, urethane resin, acrylic / urethane composite resin, olefin resin, acrylic / olefin composite resin, and the like. These may be water-soluble or in the form of an aqueous dispersion.

Further, the coating agent for exterior of the present invention comprises a curing agent (J) having a reactive group with an organic-inorganic composite resin (I) for the purpose of further improving adhesion to a substrate, scratch resistance, and weather resistance. Can be used together. In particular, the use of a curing agent that reacts with the carboxyl group of the aqueous composite resin significantly improves the abrasion resistance and weather resistance of the coating film.

Examples of the curing agent (J) that can be used include the above-mentioned silane compound (G), polycarbodiimide compound, hydrazide compound, polyepoxy compound, polyoxazoline compound, and polyisocyanate compound. It is more preferable to use an epoxy group-containing silane compound because it forms a chemical cross-link with both the shell part composed of and the core part composed of the polysiloxane (H) part, thereby greatly improving the abrasion resistance and weather resistance. preferable.

Examples of the epoxy group-containing silane compound described above include, for example,
3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane and partial hydrolysis / condensation products thereof.

The epoxy group-containing silane compound may be synthesized or a commercially available product may be used.
As a commercial product, for example,
Shin-Etsu Silicone KBM-402, 403, 303, KBE-402, 403, JNC Sila Ace S510, 520, 530, and the like.

Examples of the polycarbodiimide compound include aqueous polycarbodiimide obtained by modifying a hydrophilic group to polycarbodiimide produced from dicyclohexylmethane-4,4′-diisocyanate or 1,3-bis (2-isocyanato-2-propyl) benzene. Examples of commercially available products include Carbodilite E-02, E-03A, SV-02, V-02, V-02-L2, V-04, and E-04 manufactured by Nisshinbo.

Examples of the hydrazide compound include adipic dihydrazide.

It is preferable to use the curing agent (J) in an amount of 0.5 to 20% by weight based on 100 parts by weight of the organic-inorganic composite resin (I). By using in the above range, the abrasion resistance and weather resistance can be further improved without impairing the storage stability and coatability of the coating agent.

Further, the surface coating agent of the present invention can use various surface conditioners for the purpose of adjusting the leveling property to the substrate. Examples of the surface conditioner include Surfinol 104E, 104H, 104A, 104PA, 104PG-50, 104S, 420, 440, 465, 485, SE, SE-F, PSA-336, 61, and 2502 manufactured by Nissin Chemical Co., Ltd. DYNOL 604, 607, BYK-381, 3441, 302, 307, 325, 331, 333, 342, 345, 346, 347, 348, 349, 378, 3455 manufactured by Big Chemie.

The amount of the surface conditioner to be added is preferably about 0 to 1.0% by weight in terms of solid content in 100% by weight of the exterior coating agent in consideration of the balance of adverse effects on the properties of the coating film.

The exterior coating agent of the present invention can also contain a light stabilizer or an ultraviolet absorber for the purpose of improving weather resistance.

As the light stabilizer that can be used in the exterior coating agent of the present invention, for example,
Bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2′-n-butylmalonate, Hindered amines such as 2,2,6,6-pentamethyl-4-piperidyl) sebacate and tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate Compounds.

As the ultraviolet absorber that can be used in the exterior coating agent of the present invention, for example,
2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy -3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis [2-hydroxy-4- Butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3-tridecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [4-[(2-hydroxy-3- (2'-ethyl) hexyl) oxy] -2-hydroxy Phenyl A triazine compound such as -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine;
2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-amylphenyl) benzotriazole, 3- [3- (benzotriazole-2-) of polyethylene glycol Yl) -5-tert-butyl-4-hydroxyphenyl] propionate. Examples of benzophenones include benzotriazoles such as 2,4-dihydroxybenzophenone, 2,2 ′, 4-trihydroxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, and 2-hydroxy-4-methoxybenzophenone. Compound;
And the like.

It is preferable to add the light stabilizer and the ultraviolet absorber in an amount of about 0.5 to 10% by weight based on 100% by weight of the organic-inorganic composite resin. By adding in the above range, the weather resistance can be improved without adversely affecting the adhesion to the substrate and the abrasion resistance.

The coating agent for exterior of the present invention is applicable not only to polar substrates such as slate plates, glass plates, and metal plates, but also to non-polar plastic substrates such as PET, polyethylene, and polypropylene, and is excellent. It exhibits excellent substrate adhesion and followability.

The exterior coating agent of the present invention can be applied to various substrates by any method such as plate printing, spray coating, inkjet printing, and the like. In the drying step, it is preferable to perform a drying treatment in a range of room temperature to 150 ° C. for 60 to 1200 seconds.

Hereinafter, the present invention will be described more specifically with reference to Examples. However, the following Examples do not limit the scope of the present invention. In the examples, “parts” represents “parts by weight”, and “%” represents “% by weight”.

<Production of urethane resin containing mercapto groups at both ends>
[Production Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 85.5 parts of polytetramethylene glycol (PTG-2000 manufactured by Hodogaya Chemical Co., Ltd., functional group number 2, hydroxyl value: 57.0 mgKOH / g) as a polyol (A), 14.5 parts of isophorone diisocyanate was charged as isocyanate (B), and the temperature was raised to 80 ° C. while stirring under a nitrogen atmosphere. Thereto, 0.02 parts of titanium diisopropoxybis (ethyl acetoacetate) was added as a catalyst, and the temperature was raised to 120 ° C. and reacted for 6 hours. After the reaction, the temperature was lowered to 80 ° C, 40.0 parts of methyl ethyl ketone and 2.4 parts of 2-aminoethanethiol as a mercapto group-containing compound (D) were added, and the mixture was further reacted at 75 ° C for 2 hours. The end point of the reaction was confirmed by disappearance of a peak (around 2270 cm -1) derived from an isocyanate group by FT-IR. To further adjust the viscosity, methyl ethyl ketone was added to adjust the final solid content of the resin solution to 70.0%. The acid value of the obtained urethane resin containing mercapto groups at both ends (C-2) was 0 mgKOH / g, and the weight average molecular weight was 32,400.

[Acid value]
Number of milligrams of potassium hydroxide required to neutralize acidic components contained in 1 g of resin. The dried resin was subjected to potentiometric titration with a potassium hydroxide / ethanol solution in accordance with the method described in JIS K2501, and calculated.

[Weight average molecular weight]
The weight average molecular weight in the present specification is a value in terms of polystyrene measured by GPC (gel permeation chromatography). The dried resin was dissolved in tetrahydrofuran to prepare a 0.1% solution, and the weight average molecular weight was measured using the following apparatus and measuring conditions.
Apparatus: HLC-8320-GPC system (Tosoh Corporation)
Column: TSKgel-SuperMultipore HZ-M0021488
4.6 mm I.D. x 15 cm x 3 (Molecular weight measurement range 2000 to about 2 million)
Elution solvent; tetrahydrofuran standard substance; polystyrene (manufactured by Tosoh Corporation)
Flow rate: 0.6 mL / min, sample solution usage: 10 μL, column temperature: 40 ° C.

[Production Examples 2 to 11]
A urethane prepolymer (C-1) was synthesized by the same method as in Production Example 1 using the composition shown in Table 1, and was further reacted with the compound (D) represented by the general formula (1). A group-containing urethane resin (C-2) was obtained. After the reaction, the same operation as in Production Example 1 was performed to adjust the final solid content of the resin solution to 70.0%. The acid value and weight average molecular weight of the obtained urethane resin (c-2) containing mercapto groups at both ends were measured in the same manner as in Production Example 1.

<Polyol>
-Uniol D-2000: NOF polypropylene glycol (functional group number 2, OH value 56.0, molecular weight 2000)
PTG-2000SN: Polytetramethylene glycol manufactured by Hodogaya Chemical (functional group number 2, OH value 57.0, molecular weight 2000)
・ P-2010: Kuraray MPD / AA polyester polyol (functional group number 2, OH value 56.0, molecular weight 2000)
-P-2011: Kuraray MPD / AA / TPA-based polyester polyol (functional group number 2, OH value 55.0, molecular weight 2000)
-PriPlast3199: Croda dimer acid polyester polyol (functional group number 2, OH value 50.0, molecular weight 2200)
-T5652; 1,5-pentanediol / 1,6-hexanediol-based polycarbonate polyol manufactured by Asahi Kasei (2 functional groups, OH value 56.0, molecular weight 2000)
C-2090: Kuraray MPD / 1,6-hexanediol-based polycarbonate polyol (functional group number 2, OH value 56.0, molecular weight 2000)
GI-1000: hydrogenated polybutadiene-based polyol manufactured by Nippon Soda (functional group number 2, OH value 64.0, molecule 1000)
Here, MPD: 3-methylpentanediol, AA: adipic acid, TPA: terephthalic acid.
-MDI; dicyclohexylmethane 4,4'-diisocyanate

<Production of acrylic / urethane composite resin (F)>
[Production Example 12]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 142.9 parts (100.0 parts of a non-volatile component) of a urethane resin solution containing a mercapto group at both ends obtained in Production Example 1 and methyl methacrylate 40 2.0 parts, n-butyl methacrylate 40.0 parts, methacrylic acid 13.0 parts, 3-methacryloxypropyltrimethoxysilane 3.0 parts, styrene 4.0 parts, and isopropyl alcohol 35.3 parts, and a nitrogen atmosphere. The temperature was raised to 75 ° C. while stirring under the temperature. 20.0 parts of isopropyl alcohol and 0.35 part of 2,2′-azobis (2,4-dimethylvaleronitrile) as an initiator were charged into the dropping funnel and dropped into the reaction vessel over 5 hours. The reaction was carried out under reflux conditions for 10 hours to complete the graft polymerization of the acrylic resin portion. When the acid value and the weight average molecular weight were measured in the same manner as in the above-mentioned urethane resin having a mercapto group at both ends, the acid value of the obtained acrylic / urethane composite resin (F) was 42.4 mgKOH / g, and the weight average molecular weight was 61150. Met. Further, isopropyl alcohol was added to adjust the final solid content of the resin solution to 60.0%.

[Production Examples 13 to 30]
With the composition shown in Tables 2 and 3, an acrylic / urethane composite resin (F) was synthesized in the same manner as in Production Example 12.

Abbreviations in Tables 2 and 3 are shown below.
PME-400: NOF methoxypolyethylene glycol methacrylate (ethylene oxide addition mole number 9)

<Alkoxy resin containing alkoxysilyl group>
[Production Example 31]
53.0 parts of isopropyl alcohol was charged into a reaction vessel equipped with a stirrer, a thermometer, two dropping funnels, and a reflux condenser, and the temperature was raised to 80 ° C. under a nitrogen atmosphere while stirring. Next, in two dropping funnels, from one side, 43.5 parts of methyl methacrylate, 43.0 parts of n-butyl methacrylate, 6.5 parts of methacrylic acid, 3.0 parts of 3-methacryloxypropyltrimethoxysilane, styrene 4.0 parts were added dropwise over 4 hours. From the other side, 2.5 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved in the isopropyl alcohol part, and it was added dropwise over 4 hours. After the completion of the dropping, the reaction was further continued for 12 hours to obtain an alkoxyl group-containing acrylic resin. The final solids of the resin solution was adjusted to 60.0%. The acid value and the weight average molecular weight were measured in the same manner as for the acrylic / urethane composite resin (F). The acid value of the obtained resin was 41.3 mgKOH / g, and the weight average molecular weight was 51,800.

<Alkoxysilyl group-containing urethane resin>
[Production Example 32]
In a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 62.9 parts of polytetramethylene glycol (PTG-2000, manufactured by Hodogaya Chemical Co., Ltd., number of functional groups: 2, hydroxyl value: 57.0 mgKOH / g), dimethylolbutanoic acid One part, 26.0 parts of isophorone diisocyanate and 43.0 of methyl ethyl ketone were charged, and the temperature was raised to 80 ° C. while stirring under a nitrogen atmosphere. Thereto, 0.02 parts of titanium diisopropoxybis (ethylacetoacetate) was added as a catalyst, the temperature was raised to 120 ° C, and the mixture was reacted for 6 hours to obtain a urethane prepolymer. Thereafter, the temperature was lowered to 30 ° C., 3-aminopropyltrimethoxysilane was added, and the mixture was stirred for 4 hours to carry out a urea reaction to obtain a urethane resin having alkoxysilyl groups at both ends. Further, isopropyl alcohol was added to adjust the final solid content to 60.0%. The acid value and the weight average molecular weight were measured in the same manner as for the acrylic / urethane composite resin (F). The acid value of the obtained urethane resin was 41.8 mgKOH / g, and the weight average molecular weight was 19,300.

<Production of organic-inorganic composite resin (I)>
[Example 1]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a reflux condenser, 167.0 parts of the acrylic / urethane composite resin (F) solution obtained in Production Example 12 (100.0 parts of nonvolatile components), isopropyl alcohol 66.0 parts, 10.0 parts of n-propyltrimethoxysilane, and 40.0 parts of phenyltrimethoxysilane were added, and the temperature was raised to 78 ° C with stirring. Next, 0.4 parts of isopropyl phosphate and 12.0 parts of ion-exchanged water were added, and the mixture was stirred under an acidic condition for 4 hours to promote hydrolysis and condensation reaction. After the reaction, 6.7 parts of dimethylaminoethanol and 188.0 parts of ion-exchanged water were further added, the internal temperature was lowered to 60 ° C. or lower, and the solvent was removed by stripping under reduced pressure. Thereafter, the internal temperature was raised again to 80 ° C., and the mixture was stirred for 6 hours to proceed with the condensation reaction to obtain the desired aqueous dispersion of the organic-inorganic composite resin (I). The final solids content of the aqueous dispersion was adjusted to 30.0%. The resulting organic-inorganic composite resin (I) had an acid value of 28.2 mgKOH / g and an average particle size of 42 nm.

[Acid value]
The acid value was measured in the same manner as in the acrylic / urethane composite resin (F) described above.

[Average particle size]
The aqueous dispersion of the organic-inorganic composite resin (I) was diluted 200-fold with water, and about 5 ml of the diluted solution was measured by a dynamic light scattering measurement method (Nanotrac WaveII manufactured by Microtrac Bell). The median diameter of the obtained particle size distribution data (histogram) was defined as the average particle diameter.

[Examples 2 to 23, Comparative Examples 1 to 7]
Organic-inorganic composite resins were synthesized in the same manner as in Example 1 with the composition shown in Tables 4 to 6.
Dimethylaminoethanol as a neutralizing agent was added in such an amount that the amino group was equimolar to the anionic group of the charged acrylic / urethane composite resin (F).

-KC-89S: Shin-Etsu Silicone's partially hydrolyzed condensate of methyltrimethoxysilane [Comparative Example 8]
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a reflux condenser, 83.5 parts of the acrylic resin solution obtained in Production Example 31 (the nonvolatile component was 50.0 parts) and urethane obtained in Production Example 32 83.5 parts of a resin solution (the nonvolatile component is 50.0 parts), 66.0 parts of isopropyl alcohol, 10.0 parts of ethyltrimethoxysilane, and 40.0 parts of phenyltrimethoxysilane are added, and the mixture is heated to 78 ° C. while stirring. Warmed. Next, 0.4 parts of isopropyl phosphate and 12.0 parts of ion-exchanged water were added, and the mixture was stirred under an acidic condition for 4 hours to promote hydrolysis and condensation reaction. After the reaction, 6.7 parts of dimethylaminoethanol and 188.0 parts of ion-exchanged water were further added, the internal temperature was lowered to 60 ° C. or lower, and the solvent was removed by stripping under reduced pressure. Thereafter, the internal temperature was raised again to 80 ° C., and the mixture was stirred for 6 hours to proceed with the condensation reaction to obtain the desired aqueous dispersion of the organic-inorganic composite resin (I). The final solids content of the aqueous dispersion was adjusted to 30.0%. The resulting organic-inorganic composite resin had an acid value of 27.6 mgKOH / g and an average particle size of 323 nm.

<Production of exterior coating agent>
[Example 24]
97.0 parts of the aqueous dispersion of the organic-inorganic composite resin (I) obtained in Example 1 and 3.0 parts of diethylene glycol monobutyl ether were mixed with stirring to prepare a desired exterior coating agent. With respect to the obtained exterior coating agent solution, the average particle diameter of the aqueous dispersion of the organic-inorganic composite resin (I) was measured over time to evaluate the storage stability. Furthermore, a PET film (without corona treatment, film thickness of 100 μm), an OPP film (film thickness of 60 μm, with corona treatment), a PP plate (with corona treatment), aluminum with a bar coater so that the film thickness becomes 10 μm in dry conversion (Al) An exterior coating agent was applied to various substrates such as a plate and a glass plate, and dried at 80 ° C. for 20 minutes to prepare a coating film, and the following evaluation was performed.

[Storage stability]
The prepared solution of the exterior coating agent was allowed to stand at 50 ° C. for one day. The average particle diameter was measured in the same manner as the particle diameter measurement of the organic-inorganic composite resin (I) described above, and the change before and after standing was compared. The evaluation criteria are as follows. (Practical level is above ○)
A: The change rate of the particle diameter is less than ± 10%.
；: The change rate of the particle diameter is ± 10% or more and less than ± 30%.
Δ: The change rate of the particle diameter is ± 30% or more.
×: Measurement of particle size was not possible due to aggregation and gelation.

[Substrate adhesion]
A cellophane tape (Nichiban 18 mm width) was attached to the coating film of the five substrates coated as described above, and a peel test was performed in the vertical direction, and the adhesion of the substrate was evaluated from the ratio of the area of the peeled film. did. The evaluation criteria are as follows. (Practical level is above ○)
◎: no peeling of the coating film ○: slight peeling of the coating film (less than 10%)
△: Peeling of coating film (10% or more, less than 50%)
×: considerable peeling of coating film (50% or more)

[Substrate followability]
The PET and OPP films coated as described above were rubbed 50 times, and visually checked for cracks or peeling of the coating film. The evaluation criteria are as follows. (Practical level is above ○)
◎: No cracking or peeling of the coating film ○: Some cracking or peeling of the coating film (less than 10%)
△: Cracking or peeling of coating film (10% or more, less than 50%)
×: The coating film has considerable cracking and peeling (50% or more)

[Scratch resistance]
The PET and OPP films coated as described above were rubbed with nails 30 times, and the coated surfaces were visually observed for easiness to be scratched. The evaluation criteria are as follows. (Available level is ○)
◎: All were not damaged.
；: Less than 5 scratches occurred.
Δ: Scratched 5 times or more and less than 10 times.
×: Scratched more than 10 times.

[Weatherability]
Regarding the coated surfaces of the PP plate and the Al plate coated as described above, a Dew panel light weather meter [manufactured by Suga Test Instruments Co., Ltd., light irradiation: 30 W / m ² , 60 ° C., wet: humidity 90% or more, 40 C., light irradiation / wet cycle = 4 hours / 4 hours] for 1300 hours. The specular gloss reflectance of the surface coating film of the test plate was measured using VG-200 (gloss meter) manufactured by Nippon Denshoku Industries Co., Ltd., and the gloss retention was determined based on the following equation.
Gloss retention% = [(specular gloss after exposure test) / (specular gloss before exposure test) × 100]
The higher the value, the better the weather resistance. The evaluation criteria are as follows. (Practical level is above ○)
A: The gloss retention is 90% or more.
；: The gloss retention is 80% or more and less than 90%.
Δ: The gloss retention is 70% or more and less than 80%.
X: The gloss retention is less than 70%.

[Stain resistance]
The exposed surface of the PP plate and the Al plate coated as described above was exposed outdoors for 36 months. For the coating films before and after the exposure test, the color difference was measured with Nippon Denshoku Industries SE-2000 (color difference meter), and the light and dark difference (ΔL) was compared. The evaluation criteria are as follows. (Practical level is above ○)
A: ΔL is less than 2.
；: ΔL is 2 or more and less than 4.
Δ: ΔL is 4 or more and less than 6.
×: ΔL is 6 or more.

<Curing agent>
KBM-403; 3-glycidoxypropyltrimethoxysilane carbodilite E-02; polycarbodiimide emulsion manufactured by Nisshinbo Chemical Inc. (polycarbodiimide derived from dicyclohexylmethane 4,4′-diisocyanate skeleton, NV 40%, carbodiimide equivalent 445) )

[Examples 25 to 46, Comparative Examples 9 to 16]
After preparing an exterior coating agent in the same manner as in Example 24 using the composition shown in Tables 7 to 9, storage stability, substrate adhesion, substrate followability, and scratch resistance were obtained in the same manner as in Example 1. The properties, weather resistance and stain resistance were evaluated.

As shown in Tables 7 to 9, the exterior coating agents of Examples 24 to 46 containing the aqueous composite resins of Examples 1 to 23 have good storage stability, and their dried coating films The adhesiveness to the base material, followability, scratch resistance, and weather resistance were very excellent, and it was found that the level was sufficiently practical. On the other hand, the exterior coating agents of Comparative Examples 9 to 16 containing the aqueous composite resins of Comparative Examples 1 to 8 were inferior in all or any of the above physical properties and did not satisfy the practical level. From the above, the superiority of the organic-inorganic composite resin (I) of the present invention and the exterior coating agent containing the same were proved.

Claims (8)

A urethane prepolymer (C-1) obtained by reacting a polyol (A) with a polyisocyanate (B) and a compound (D) represented by the general formula (1) reacted with a urethane containing a mercapto group at both ends. Acrylic / urethane composite obtained by polymerizing an ethylenically unsaturated monomer (E) containing an alkoxysilyl group-containing ethylenically unsaturated monomer (e-1) using a resin (C-2) as a chain transfer agent A resin (F) and a polysiloxane (H) obtained by hydrolyzing and condensing the silane compound (G),
An organotrialkoxysilane (g-1) having a linear or alicyclic alkyl group having 3 to 10 carbon atoms or a phenyl group in 100% by weight of the silane compound (G), and / or diorgano Aqueous composite resin (I) containing dialkoxysilane (g-2) in a total amount of 55 to 100% by weight.
General formula (1)

(In the general formula (1), X is at least one selected from the group consisting of —OH, —NH ₂ , —NHR ₁ , and —SH, and R ₁ is an alkyl group.
R is at least one divalent group selected from the group consisting of an alkylene group, an arylene group, and an alkylene oxide group. ) The aqueous composite resin (I) according to claim 1, wherein the compound (D) represented by the general formula (1) is an aminoalkanethiol. The aqueous solution according to claim 1 or 2, wherein at least one of the polyether polyol (a-1) and the polycarbonate polyol (a-3) is contained in an amount of 70 to 100% by weight based on 100% by weight of the polyol (A). Composite resin (I). The content of the ethylenically unsaturated monomer (E) is in the range of 50 to 200 parts by weight based on 100 parts by weight of the urethane urea resin (C-2) containing both ends of the mercapto group. The aqueous composite resin (I) as described above. The aqueous composite resin (I) according to any one of claims 1 to 4, wherein the content of the silane compound (G) is in the range of 35 to 120 parts by weight based on 100 parts by weight of the acrylic / urethane composite resin (F). The aqueous composite resin (I) according to any one of claims 1 to 5, wherein the average particle diameter is in a range of 30 to 180 nm. An exterior coating agent containing the aqueous composite resin (I) according to claim 1. The exterior coating agent according to claim 7, further comprising a curing agent (J) having a reactive group.