JP2012218209A - Method for manufacturing protective sheet for solar cell and protective sheet for solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sollar cell with a protective coat which is excellent in UV cut property, weatherability, and adhesion without the need to use an expensive device, using a coating agent using an aqueous medium.SOLUTION: The method for manufacturing a protective sheet for a solar cell includes the step of applying a composition containing (A) particles including a polysiloxane (and an acrylic polymer), (B) at least one selected from the group consisting of metal oxide particles and an ultraviolet absorber, and (C) the aqueous medium to a transparent base material and drying the applied composition to form a protective layer.

Description

  The present invention relates to a method for producing a solar cell protective sheet and a solar cell protective sheet.

The present invention generally relates to a solar cell back surface protective sheet disposed on the back surface side of a solar cell module.
Since solar cell modules are often installed outdoors due to their nature, for the purpose of protecting solar cell elements, electrodes, wiring, etc., a transparent glass plate, for example, is disposed on the front side, and on the back side, For example, a laminated sheet of an aluminum foil and a resin film, a laminated sheet of a resin film, or the like is disposed.
The solar cell back surface protection sheet disposed on the back surface side of the solar cell module is also called a back sheet, and is required to have weather resistance and moisture resistance in order to protect the solar cell module installed outdoors.
Moreover, the effect of reflecting the sunlight which permeate | transmitted to the back surface side to the solar cell element side, and improving conversion efficiency using the reflected light is also anticipated by the back surface protection sheet.
Conventionally, the back surface protection sheet is manufactured by kneading protective components such as particles and UV absorbers into the resin film, or depositing these protective components on the resin film, and applying a fluororesin coating agent to the resin film. It was.
However, in order to knead or deposit the protective component on the resin film, an expensive apparatus is required, and to apply the fluororesin coating agent, an organic solvent is used to dissolve the fluororesin. Is not desirable for the human body and environment.

JP 2010-232442 A

  The present invention has been made in the background as described above, and it is not necessary to use an expensive apparatus, and it is excellent in UV cutability, weather resistance, and adhesion while using a coating agent using an aqueous medium. The purpose is to provide a protective coating on the solar cell.

（式中、Ｒ^１は水素原子または炭素数１〜８の１価の有機基を示し、複数存在するＲ^１は相互に同一でも異なってもよく、Ｒ^２は水素原子、炭素数１〜５のアルキル基または炭素数１〜６のアシル基を示し、複数存在するＲ^２は相互に同一でも異なっていてもよく、ｎは２〜４の整数である。）で表されるオルガノシランの加水分解縮合物であることを特徴とする前記太陽電池保護シートの製造方法、
金属酸化物粒子が、酸化チタン、酸化亜鉛、酸化セリウムから選ばれることを特徴とする前記太陽電池保護シートの製造方法、
紫外線吸収剤がベンゾトリアゾール系紫外線吸収剤、トリアジン系紫外線吸収剤、ベンゾフェノン系紫外線吸収剤から選ばれることを特徴とする前記太陽電池保護シートの製造方法、
（Ａ）成分の含有量が組成物の１０〜３５質量％であることを特徴とする前記太陽電池保護シートの製造方法、
（Ｂ）成分の金属酸化物の含有量が組成物の（Ａ）成分１００質量部に対して１０〜２００質量部であることを特徴とする前記太陽電池保護シートの製造方法、
（Ａ）ポリシロキサンおよびアクリル系重合体を含む粒子、（Ｂ）金属酸化物粒子および紫外線吸収剤から選ばれる少なくとも１種ならびに（Ｃ）水系媒体を含む組成物を塗布し、乾燥してなる塗膜の厚さが３〜８μｍであることを特徴とする前記太陽電池保護シートの製造方法、
ならびに前記製造方法により製造された太陽電池保護シートを提供するものである。 The present invention is a composition comprising (A) particles containing polysiloxane (and acrylic polymer), (B) metal oxide particles and an ultraviolet absorber, and (C) an aqueous medium in a transparent substrate. A method for producing a solar cell protective sheet, comprising a step of applying and drying an object,
The polysiloxane in component (A) is represented by the following general formula (1)

(In the formula, R ¹ represents a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms, a plurality of R ¹ may be the same or different from each other, and R ² represents a hydrogen atom or a carbon number of 1 to 5) Or an acyl group having 1 to 6 carbon atoms, and a plurality of R ² may be the same or different from each other, and n is an integer of 2 to 4). A method for producing the solar cell protective sheet, which is a decomposition condensate,
The method for producing a solar cell protective sheet, wherein the metal oxide particles are selected from titanium oxide, zinc oxide, and cerium oxide,
The method for producing a solar cell protective sheet, wherein the ultraviolet absorber is selected from benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers,
(A) Content of component is 10-35 mass% of a composition, The manufacturing method of the said solar cell protective sheet characterized by the above-mentioned,
(B) The manufacturing method of the said solar cell protective sheet characterized by the content of the metal oxide of a component being 10-200 mass parts with respect to 100 mass parts of (A) component of a composition,
(A) Particles containing polysiloxane and acrylic polymer, (B) At least one selected from metal oxide particles and ultraviolet absorbers, and (C) A composition containing an aqueous medium, and drying. The method for producing the solar cell protective sheet, wherein the thickness of the film is 3 to 8 μm,
And the solar cell protection sheet manufactured by the said manufacturing method is provided.

  According to the method for producing a solar cell protective sheet of the present invention, since the medium is an aqueous medium, there is little influence on the environment in that it is not necessary to use an organic solvent, and sufficient UV cutability, weather resistance and A solar cell protective sheet having adhesion can be obtained.

(Transparent substrate)
The type of the transparent substrate used in the present invention is not particularly limited. For example, glass, polycarbonate resin, polyester resin such as polyethylene terephthalate (PET), acrylic resin, triacetyl cellulose resin (TAC), etc. Among these, polyethylene terephthalate is preferably used.
The surface of the transparent substrate can be subjected to plasma treatment, corona treatment, primer coating treatment and the like.
The thickness of the transparent substrate is usually 20 to 300 μm, preferably 25 to 250 μm.

The composition used for forming the protective layer in the present invention is at least one selected from (A) particles containing polysiloxane (and acrylic polymer), (B) metal oxide particles and an ultraviolet absorber, and ( C) It contains an aqueous medium.

(A) Particles containing polysiloxane and acrylic polymer (hereinafter referred to as “specific composite particles”)
The particles containing the polyorganosiloxane and the acrylic polymer in the present invention are not particularly limited as long as the polyorganosiloxane and the acrylic polymer are combined. The phase preferably forms a network structure in which the polyorganosiloxane and the acrylic polymer penetrate each other (that is, an interpenetrating network structure).
Below, the polyorganosiloxane / acrylic polymer composite resin containing a polysiloxane and an acrylic polymer that can form an interpenetrating network structure when formed into a dry coating film, and a method for producing the same are described.

In the component (A) of the present invention, as a preferred polysiloxane and acrylic polymer composite resin, (I) polysiloxane is represented by the following general formula (1):

（式中、Ｒ^１は水素原子または炭素数１〜８の１価の有機基を示し、複数存在するＲ^１は相互に同一でも異なってもよく、Ｒ^２は水素原子、炭素数１〜５のアルキル基または炭素数１〜６のアシル基を示し、複数存在するＲ^２は相互に同一でも異なってもよく、ｎは２〜４の整数である。）
で表されるオルガノシラン（以下、「オルガノシラン（１）」という。）、オルガノシラン（１）の加水分解物およびオルガノシラン（１）の部分縮合物の群から選ばれる少なくとも１種から得られるポリオルガノシロキサン、並びに（ＩＩ）ガラス転移点が−２０℃〜＋８０℃のアクリル系重合体からなるポリオルガノシロキサンおよびアクリル系重合体複合樹脂を挙げることができる。
以下に、このポリオルガノシロキサンおよびアクリル系重合体複合樹脂について説明する。

(In the formula, R ¹ represents a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms, a plurality of R ¹ may be the same or different from each other, and R ² represents a hydrogen atom or a carbon number of 1 to 5) A plurality of R ² may be the same as or different from each other, and n is an integer of 2 to 4.)
It is obtained from at least one selected from the group consisting of an organosilane (hereinafter referred to as “organosilane (1)”), a hydrolyzate of organosilane (1), and a partial condensate of organosilane (1). Examples thereof include polyorganosiloxanes and (II) polyorganosiloxanes and acrylic polymer composite resins made of acrylic polymers having a glass transition point of -20 ° C to + 80 ° C.
The polyorganosiloxane and the acrylic polymer composite resin will be described below.

-(I) Polyorganosiloxane-
In the general formula (1), examples of the monovalent organic group having 1 to 8 carbon atoms of R ¹ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl. Group, sec-butyl group, tert-butyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group and other alkyl groups; phenyl group; acetyl group, propionyl group, butyryl group, valeryl group , Acyl groups such as benzoyl group, trioyl group, caproyl group; vinyl group, allyl group, cyclohexyl group, phenyl group, 3,4-epoxycyclohexylethyl group, 3-glycidoxypropyl group, 3- (meth) acryloxy In addition to a propyl group, a ureido group, an amide group, a fluoroacetamide group, an isocyanate group, etc., substituted derivatives of these groups can be exemplified.
Examples of the substituent in the substituted derivative include a halogen atom, a substituted or unsubstituted amino group, a hydroxyl group, a mercapto group, an isocyanate group, a glycidoxy group, a 3,4-epoxycyclohexyl group, a (meth) acryloxy group, and a ureido. Group, ammonium base and the like. However, the carbon number of the organic group consisting of these substituted derivatives is 8 or less including the carbon atom in the substituent.
Examples of the alkyl group having 1 to 5 carbon atoms of R ² include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and n. -A pentyl group etc. can be mentioned, As a C1-C6 acyl group, an acetyl group, a propionyl group, a butyryl group, a valeryl group, a caproyl group etc. can be mentioned, for example.

Specific examples of the organosilane (1) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane;
Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n- Butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, Cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxy Silane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxy Propyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- Trialkoxysilanes such as (meth) acryloxypropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane;

Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxy Silane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldi Ethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane, diphenyldimethoxysilane Down, other dialkoxy silanes such as diphenyl diethoxy silane, methyl triacetyl silane, dimethyl di acetyloxy silane.
Of these organosilanes (1), trialkoxysilanes and dialkoxysilanes are preferable. As the trialkoxysilanes, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane and the like are preferable. As the dialkoxysilanes, dimethyldimethoxysilane, dimethyldiethoxysilane and the like are preferable. In terms of the weather resistance of the coating film, it is preferable not to use tetraalkoxysilanes alone.

The polyorganosiloxane in the component (A) of the present invention is at least one selected from organosilane (1), hydrolyzate of organosilane (1), and partial condensate of organosilane (1) (hereinafter referred to as “organo”). It is made of polyorganosiloxane obtained from silane (1) or its hydrolyzed / condensed product. The hydrolyzate of organosilane (1) is not required to have all the OR ² groups in organosilane (1) hydrolyzed. For example, only one hydrolyzed product is hydrolyzed. It may be decomposed or a mixture thereof.

Moreover, the partial condensate of organosilane (1) was partially condensed to the extent that the silanol group of the hydrolyzate of organosilane (1) did not reach the final polyorganosiloxane to form a Si—O—Si bond. However, it is not necessary that all the silanol groups are condensed, and it is a concept that includes a mixture of some of the silanol groups, a mixture of those having different degrees of condensation, and the organosilane (1). The OR ² group in it may remain. When the aqueous resin dispersion of the present invention is produced, the component (a) described later contains a partial condensate of organosilane (1), so that the polymerization stability when the radical polymerizable monomer is polymerized is increased. Since it is improved and can be polymerized at a high solid content, there is also an advantage that it is industrially advantageous.

When preparing a hydrolyzate or partial condensate of organosilane (1), by adding an appropriate amount of water, hydrolysis / condensation catalyst to organosilane (1), an organic solvent as required, It is preferable to hydrolyze and condense the organosilane. The amount of water used in this case is usually about 1.2 to 3.0 mol, preferably about 1.3 to 2.0 mol, per 1 mol of organosilane (1). Examples of the hydrolysis / condensation catalyst include those similar to the hydrolysis / condensation catalyst used in the production of particles containing polysiloxane and an acrylic polymer, which will be described later.

The organic solvent is not particularly limited as long as it can uniformly dissolve organosilane (1) or a hydrolysis / condensation product thereof. For example, alcohols, aromatic hydrocarbons, ethers, ketones And esters.
Specific examples of the alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-hexyl alcohol, n-octyl alcohol, and ethylene glycol. And diethylene glycol, triethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, diacetone alcohol and the like.

Specific examples of the aromatic hydrocarbons include benzene, toluene and xylene, specific examples of the ethers include tetrahydrofuran and dioxane, and specific examples of the ketones include acetone, methyl ethyl ketone, and methyl. Specific examples of the esters such as isobutyl ketone and diisobutyl ketone include ethyl acetate, n-propyl acetate, n-butyl acetate, propylene carbonate, propylene monomethyl ether acetate and the like.
These organic solvents can be used alone or in admixture of two or more.
In addition, when using an organic solvent at the time of preparation of the hydrolyzate or partial condensate of organosilane (1), it is preferable to remove the organic solvent prior to the condensation / polymerization reaction described later.

Mw of the partial condensate of organosilane (1) is preferably 800 to 100,000, more preferably 1,000 to 50,000.
In addition, commercially available products of hydrolyzates or partial condensates of organosilane (1) include, under the trade names, MKC silicate manufactured by Mitsubishi Chemical; ethyl silicate manufactured by Colcoat; “SX101” and “SR2402” manufactured by Toray Dow Corning. ”,“ DC3037 ”,“ DC3074 ”,“ SH6018 ”,“ DC6-2230 ”and other silicon resins; Momentive“ TSR160 ”,“ TSR165 ”and other silicon resins,“ XF3905 ”,“ YF3800 ”,“ XC96- Hydroxyl group-containing polydimethylsiloxane such as “723”; silicon resins such as “X40-9220”, “X40-9225”, and “KC89” manufactured by Shin-Etsu Chemical; hydroxyl group-containing polydimethylsiloxane manufactured by Dow Corning Asia; Japan There are silicone oligomers made by Unica, Intact these, or even may be used in the condensation.

The organosilane (1) or its hydrolysis / condensation product used for the preparation of the polyorganosiloxane in the component (A) preferably has an alkoxy group having a total number of moles or more of silanol groups contained therein.
Examples of such organosilane (1) or a hydrolysis / condensation product thereof include the following.
(A) Organosilane (1) having an alkoxy group as R ^{2 in the} general formula (1).
(A) Among the partial condensates of organosilane (1), those having an alkoxy group.
Commercially available products of partial condensates of this organosilane (1) are “SX101” and “SR2402” manufactured by Toray Dow Corning; “X40-9220” and “X40-9225” manufactured by Shin-Etsu Chemical Co., Ltd. “KC89”; “TSR165” manufactured by Momentive and the like.
In order to make the organosilane (1) or its hydrolysis / condensation product have an alkoxy group having at least the total number of moles of silanol groups, an organosilane (1) having an appropriate amount of alkoxy group and / or a partial condensate thereof is used. The contained organosilane (1) or a hydrolysis / condensation product thereof may be used.
There exists a possibility that the weather resistance of a coating film may become inadequate that the number of moles of an alkoxy group is less than the total number of moles of a silanol group.

-(II) Acrylic polymer-
The acrylic polymer in the present invention is composed of a (co) polymer of radical polymerizable monomers containing at least one acrylic monomer.
Examples of the acrylic monomer include (meth) acrylic acid;
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-amyl (meth) acrylate, i-amyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (Meth) acrylates such as (meth) acrylate and isobornyl (meth) acrylate;
Hydroxyl group-containing (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate;

Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, Tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate Polyfunctional (meth) acrylates such as
Fluorine atom-containing (meth) acrylates such as trifluoroethyl (meth) acrylate and pentadecafluoro-n-octyl (meth) acrylate;
Amino group-containing (meth) acrylates such as 2-aminoethyl (meth) acrylate, 2-aminopropyl (meth) acrylate, and 3-aminopropyl (meth) acrylate;

Epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate;
Dialkylaminoalkyl group-containing (meth) acrylates such as 2-dimethylaminoethyl (meth) acrylate, 2-diethylaminoethyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, and 3-dimethylaminopropyl (meth) acrylate ;
Under the trade name, NOF's BLEMMER PE-90, PE-200, PE-350, PME-100, PME-200, PME-400, AE-350;
Contains polyoxyethylene groups such as MA-30, MA-50, MA-100, MA-150, RA-1120, RA-2614, RMA-564, RMA-568, RMA-1114 and MPG130-MA made by Nippon Emulsifier (Meth) acrylates;

Diacetone (meth) acrylamide, diacetone (meth) acrylate, acetonitrile (meth) acrylate, 2-hydroxypropyl (meth) acrylate-acetyl acetate, 3-hydroxypropyl (meth) acrylate-acetyl acetate, 2-hydroxybutyl (meth) acrylate Aldehyde groups and / or ketones such as acetyl acetate, 3-hydroxybutyl (meth) acrylate-acetyl acetate, 4-hydroxybutyl (meth) acrylate-acetyl acetate, butanediol-1,4- (meth) acrylate-acetyl acetate Group-containing (meth) acrylates;
Vinyl cyanide compounds such as (meth) acrylonitrile and vinylidene cyanide;
4- (meth) acryloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acrylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloxy-1, (Meth) acryloxy group-containing piperidine monomers such as 2,2,6,6-pentamethylpiperidine;

(Meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, Nn-butoxymethyl (meth) acrylamide, N, N′-methylenebisacrylamide, N, N-dimethyl (meta ) N, N-dialkyl (meth) such as acrylamide, N, N-diethyl (meth) acrylamide, N, N-di-n-propyl (meth) acrylamide, N, N-di-i-propyl (meth) acrylamide (Meth) acrylamide or derivatives thereof such as acrylamides;
An ultraviolet absorber and / or a light stabilizer having a (meth) acryloxy group, which will be described later;
The (meth) acryloxy group containing silane coupling agent mentioned later etc. can be mentioned.
These acrylic monomers can be used alone or in admixture of two or more.

As acrylic monomers in the present invention, (meth) acrylic acid, (meth) acrylates, hydroxyl group-containing (meth) acrylates, aldehyde group and / or ketone group-containing (meth) acrylates, and (meth) acryloxy group-containing The main component is at least one selected from the group of silane coupling agents, and in some cases a dialkylaminoalkyl group-containing (meth) acrylate, a polyoxyethylene group-containing (meth) acrylate and N, N-dialkyl ( Those containing at least one selected from the group of (meth) acrylamides are preferred, more preferably acrylic acid, methacrylic acid, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, cyclohexylmedium. The main component is at least one selected from the group consisting of acrylate, 2-hydroxyethyl methacrylate, diacetone acrylamide and 3-methacryloyloxypropyltrimethoxysilane, and in some cases, 2-dimethylaminoethyl (meth) acrylate, polyoxyethylene chain Contains at least one selected from the group consisting of polyoxyethylene group-containing (meth) acrylates having 2 to 30 oxyethylene units, N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide Is a thing.

The acrylic monomer contains at least one selected from the group of (meth) acrylates containing dialkylaminoalkyl groups, (meth) acrylic acid esters having polyoxyethylene groups, and N, N-dialkyl (meth) acrylamides By doing so, a coating film excellent in frost damage resistance can be obtained without reducing the blocking resistance, the mechanical stability of the component (A) is improved, and the pigment dispersibility is also improved.
Total content of dialkylaminoalkyl group-containing (meth) acrylates, polyoxyethylene group-containing (meth) acrylates and N, N-dialkyl (meth) acrylamides in radically polymerizable monomers that give acrylic polymers Is preferably 10% by weight or less, more preferably 0.5 to 5% by weight.

In the acrylic polymer of the present invention, one or more other radical polymerizable monomers can be used in combination with the acrylic monomer.
Examples of the other radical polymerizable monomers include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene, 4-ethylstyrene, 4-ethoxystyrene, 3,4-dimethylstyrene, 3,4-diethylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chloro-3-methylstyrene, 4-tert-butylstyrene, 2,4-dichloro Aromatic vinyl monomers such as styrene, 2,6-dichlorostyrene, 1-vinylnaphthalene, divinylbenzene;

Other unsaturated carboxylic acids or unsaturated carboxylic acid anhydrides such as crotonic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride;
Unsaturated dicarboxylic amides or unsaturated dicarboxylic imides such as maleic amide and maleimide;
Other hydroxyl group-containing vinyl monomers such as N-methylol vinyl ether and 2-hydroxyethyl vinyl ether;
1,1,1-trimethylamine (meth) acrylimide, 1-methyl-1-ethylamine (meth) acrylimide, 1,1-dimethyl-1- (2-hydroxypropyl) amine (meth) acrylimide, 1,1 -Amineimide groups such as dimethyl-1- (2-phenyl-2-hydroxyethyl) amine (meth) acrylimide, 1,1-dimethyl-1- (2-hydroxy-2-phenoxypropyl) amine (meth) acrylimide Containing vinyl monomers;
Other amino group-containing vinyl monomers such as 2-aminoethyl vinyl ether;

Other epoxy group-containing vinyl monomers such as allyl glycidyl ether;
C4-C7 vinyl alkyl ketones (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl-n-propyl ketone, vinyl-i-propyl ketone, vinyl-n-butyl ketone, vinyl-i-butyl ketone, vinyl-tert -Butyl ketone, etc.), vinyl phenyl ketone, vinyl benzyl ketone, divinyl ketone and other aldehyde groups and / or ketone group-containing vinyl monomers;
Dicaprolactone;
The vinyl group containing silane coupling agent etc. which are mentioned later can be mentioned.

The content of the other radical polymerizable monomer in the radical polymerizable monomer that gives the acrylic polymer is usually 50% by weight or less, preferably 30% by weight or less.

The glass transition point of the acrylic polymer in the present invention is -20 ° C to + 80 ° C, preferably 0 to 60 ° C. By setting the glass transition point within this range, it is possible to obtain a dry coating film having an excellent balance of blocking resistance / frost resistance. This glass transition point can be easily adjusted by changing the type and ratio of the monomer.
The Mw of the acrylic polymer in the present invention is usually 10,000 to 10,000,000, preferably 100,000 to 1,000,000.

The content of the component (I) and the component (II) in the specific composite particles in the present invention is such that the component (I) is 5 to 80 parts by weight, preferably 10 to 80 parts by weight in terms of complete hydrolysis / condensate. And the component (B) is 95 to 20 parts by weight, preferably 90 to 20 parts by weight (provided that (I) + (II) = 100 parts by weight). When the amount of component (I) used is less than 5 parts by weight, the weather resistance of the coating film decreases, and when it exceeds 80 parts by weight, the adhesion of the coating film decreases.
Here, the completely hydrolyzed / condensed product refers to a product in which the OR ² group in the organosilane (1) is completely hydrolyzed to become a silanol group and further completely condensed to form a siloxane structure. However, in the polyorganosiloxane and acrylic polymer composite resin in the present invention, the organosilane (1) does not necessarily have to be completely hydrolyzed / condensed, and usually it is not hydrolyzed alkoxy group or condensed. Contains no silanol groups. The non-hydrolyzed alkoxy group and the non-condensed silanol group contribute to the formation of a coating film having good weather resistance by performing a dealcoholization reaction or a dehydration reaction after coating.
The polyorganosiloxane and acrylic polymer composite resin in the present invention are preferably dispersed as particles (hereinafter simply referred to as “specific composite particles”) in the component (A) of the present invention.
Hereinafter, the specific composite particles will be described.
-Specific composite particles-
The method for preparing the specific composite particles in the present invention is not particularly limited, but a preferable production method is (a) an organosilane (1) or a hydrolyzed / condensed product thereof, (b) ( II) A radically polymerizable monomer that gives an acrylic polymer, and (c) an emulsifier is mixed to emulsify, and (a) the hydrolysis / condensation reaction of the component proceeds, the emulsion is refined, and (d) In this method, the component (b) is radically polymerized in the presence of a radical polymerization initiator to obtain specific composite particles composed of (I) polyorganosiloxane and (II) acrylic polymer as an aqueous dispersion.

In the preparation method of the specific composite particles, the radical polymerization of the component (b) after refining the emulsion can be said to be one type of miniemulsion polymerization, and the following (1) to (1) to It has the advantage of (4).
(1) Since the hydrolysis reaction of the component (a) is substantially completed before the radical polymerization of the component (b), during the radical polymerization of the component (b), the alcohol as a by-product of the hydrolysis reaction The concentration does not change, and as a result, even when a relatively large amount of polyorganosiloxane is present in the polymerization system, the reaction stability of the radical polymerization of the component (b) is good.

(2) Since the radical polymerization of the component (b) proceeds in the presence of polyorganosiloxane in the emulsion particles, the polyorganosiloxane and the resulting acrylic polymer are in the aqueous resin dispersion formed. Uniformly mixed, the polyorganosiloxane and the acrylic polymer form an interpenetrating network structure (IPN). As a result, even when methyl polysiloxane having low mutual solubility is used as the polyorganosiloxane component, a coating film having excellent transparency is formed, and the defects in characteristics of both polymers are complemented with each other. As a result, the specific composite particles can contain a large amount of polyorganosiloxane having high hardness, chemical resistance, and weather resistance, so that it has excellent film-forming properties, such as scratch resistance, weather resistance, chemical resistance, flexibility, etc. Gives a uniform coating with good properties.

(3) In emulsion particles, since the polymers coexist in a solvent-free state, the degree of freedom of silanol groups rich in condensation reactivity in component (a) is limited, and the condensation reaction of silanol groups is suppressed. The storage stability of the specific composite particles becomes good. On the other hand, the high curing activity of the silanol group is retained, and excellent curability is ensured even at a relatively low temperature when an aqueous resin dispersion is obtained. Furthermore, by including a large amount of silanol groups based on dialkoxysilanes in component (a), it is possible to introduce a large number of linear structures into the polyorganosiloxane, and at the same time have the conflicting properties of flexibility and hardness in the coating film. Can be granted.

(4) Since the radical polymerization of component (b) proceeds following the hydrolysis / condensation reaction of component (a) in the presence of component (b), component (a) was previously hydrolyzed and isolated. Compared with the use of hydrolyzate or partial condensate containing silanol group dissolved in radical polymerizable monomer or aqueous medium, silanol group has higher reaction activity, and interparticle cross-linking reaction proceeds rapidly in the coating film. As a result, a high level of weather resistance can be expressed.

Examples of the emulsifier used for the preparation of the specific composite particles include anionic surfactants such as alkyl sulfate ester salts, alkylaryl sulfate ester salts, alkyl phosphate ester salts, and fatty acid salts;
Cationic surfactants such as alkylamine salts and quaternary ammonium salts;
Nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, block polyether;
Amphoteric surfactants such as carboxylic acid types (for example, amino acid type, betaine type, etc.) and the following trade names: LATEMUL S-180A manufactured by Kao; Eleminol JS-2 manufactured by Sanyo Kasei; Aqualon manufactured by Daiichi Kogyo Seiyaku KH-10; Adeka Soap SE-10N, SR-10N manufactured by ADEKA; Antox MS-60 manufactured by Nippon Emulsifier; Reactive emulsifier such as Surfmer FP-120 manufactured by Toho Chemical Industry, etc. can be used. In particular, a reactive emulsifier is preferable in that a coating film excellent in weather resistance and water resistance can be obtained.

As the reactive emulsifier, in particular, polyoxyethylene having a hydrophobic group such as an alkyl group having 8 or more carbon atoms in one molecule, a hydrophilic group containing a polyoxyethylene chain, and a radically polymerizable unsaturated bond. Chain containing reactive emulsifiers are preferred. The terminal of the polyoxyethylene chain in the polyoxyethylene chain-containing reactive emulsifier may be esterified with a sulfate ester or the like.

As a reactive emulsifier having a polyoxyethylene chain whose terminal is not esterified, for example, α- [1- [Adeka Soap NE-20 manufactured by ADEKA, such as NE-20, NE-30, NE-40, etc. (Allyloxy) methyl] -2- (nonylphenoxy) ethyl] -ω-hydroxypolyoxyethylene; polyoxyethylene alkyl such as Aqualon RN-10, RN-20, RN-30, RN-50 manufactured by Daiichi Kogyo Seiyaku Nonionic surfactants such as propenyl phenyl ether can be mentioned.
Moreover, as a reactive emulsifier which has the polyoxyethylene chain by which the terminal is esterified, it is a brand name, for example, Sanyo Kasei Elemiol JS-2, JS-5; Kao Latemu S-120, S- Examples include 180A, S-180; Aqualon HS-10, KH-5, KH-10 manufactured by Daiichi Kogyo Seiyaku; Adeka Soap SE-10N, SR-10N manufactured by ADEKA, and the like.
In the preparation of the specific composite particles, the emulsifiers can be used alone or in admixture of two or more. In particular, the polyoxyethylene chain-containing reactive emulsifier is non-reactive such as sodium dodecylbenzenesulfonate. By using together with an emulsifier, a high balance between polymerization stability and weather resistance can be ensured.
The amount of the emulsifier used is usually 0.1 to 5 parts by weight, preferably 0.2 to 5 parts per 100 parts by weight of the total of component (a) (completely hydrolyzed / condensed product) and component (b). Part by weight, more preferably 0.5 to 5 parts by weight. If the amount of the emulsifier used is less than 0.1 parts by weight, it is difficult to uniformly emulsify the reaction components and the stability of the emulsion is lowered. On the other hand, if it exceeds 5 parts by weight, foaming increases, which is not preferred.

In preparing the specific composite particles, water is usually used as an aqueous medium. The water may be water added in advance during the preparation of the component (a), or water added together with the emulsifier (c) separately from the component (a).
The amount of water used is usually 50 to 2,000 parts by weight, preferably 80 to 1, based on 100 parts by weight of the total of component (a) (completely hydrolyzed / condensed product) and component (b). 000 parts by weight, more preferably 100 to 500 parts by weight. If the amount of water used is less than 50 parts by weight, it is difficult to uniformly emulsify the reaction components and the stability of the emulsion is lowered, which is not preferable. On the other hand, if it exceeds 2,000 parts by weight, the productivity of specific composite particles is reduced. Therefore, it is not preferable.
In preparing the specific composite particles, a catalyst that promotes the hydrolysis reaction and / or condensation reaction of the component (a) (hereinafter referred to as “hydrolysis / condensation catalyst”) is usually used. By using a hydrolysis / condensation catalyst, the stability of the emulsion during radical polymerization of the component (b) is improved, and the molecular weight of the polyorganosiloxane produced by the condensation reaction of the component (a) used is large. Thus, a coating film excellent in strength, long-term durability and the like can be obtained, and the coating film can be thickened and painted easily.

Examples of the hydrolysis / condensation catalyst include acidic compounds, alkaline compounds, salt compounds, amine compounds, organometallic compounds and / or partial hydrolysates thereof (hereinafter, organometallic compounds and / or partial hydrolysates are collectively referred to as “organic "Metal compounds etc.") is preferred.
Examples of the acidic compound include itaconic acid, acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, alkyltitanic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, phthalic acid, and preferably acetic acid, dodecyl Such as benzenesulfonic acid. Radical polymerizable unsaturated carboxylic acids such as (meth) acrylic acid are also included in this acidic compound and copolymerize as component (b), so that the coating film can maintain good weather resistance and water resistance over a long period of time. An effect is obtained.
Examples of the alkaline compound include sodium hydroxide, potassium hydroxide, and ammonia. Sodium hydroxide or ammonia is preferable.
In addition, examples of the salt compound include alkali metal salts of acids such as naphthenic acid, octylic acid, nitrous acid, sulfurous acid, aluminate, and carbonic acid.

Examples of the amine compound include ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, piperidine, piperazine, m-phenylenediamine, p-phenylenediamine, ethanolamine, triethylamine, and 3-aminopropyl. Trimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) -aminopropyltrimethoxysilane, 3- (2-aminoethyl) -aminopropyltriethoxysilane, 3- (2-aminoethyl) ) -Aminopropylmethyldimethoxysilane, 3-anilinopropyltrimethoxysilane, alkylamine salts, quaternary ammonium salts, various modified amines used as curing agents for epoxy resins, etc. Can be mentioned, preferably, 3-aminopropyltrimethoxysilane,
3-aminopropyltriethoxysilane, 3- (2-aminoethyl) -aminopropyltrimethoxysilane, and the like.

Examples of the organometallic compound include a compound represented by the following general formula (2) (hereinafter referred to as “organometallic compound (2)”) and an alkyl group having 1 to 10 carbon atoms bonded to the same tin atom. And tetravalent tin organometallic compounds (hereinafter referred to as “organotin compounds”), partial hydrolysates of these compounds, and the like.

General formula (2)

[In the formula, M represents zirconium, titanium or aluminum, and R ³ and R ⁴ each independently represent an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group. A monovalent hydrocarbon group having 1 to 6 carbon atoms such as a group, an n-pentyl group, an n-hexyl group, a cyclohexyl group, and a phenyl group, and R ⁵ has the same carbon numbers 1 to ³ as R ³ and R ⁴ . 6 monovalent hydrocarbon group, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, lauryloxy group, stearyloxy group, etc. Wherein R and s are each an integer of 0 to 4, and (r + s) = (valence of M). ]

Specific examples of the organometallic compound (2) include tetra-n-butoxyzirconium, tri-n-butoxy (ethylacetoacetate) zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate). Organic zirconium compounds such as acetate) zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium;
Organic titanium compounds such as tetra-i-propoxy titanium, di-i-propoxy bis (ethyl acetoacetate) titanium, di-i-propoxy bis (acetyl acetate) titanium, di-i-propoxy bis (acetylacetone) titanium;
Tri-i-propoxyaluminum, di-i-propoxy (ethylacetoacetate) aluminum, di-i-propoxy (acetylacetonate) aluminum, i-propoxybis (ethylacetoacetate) aluminum, i-propoxybis (acetylacetonate) And organic aluminum compounds such as aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonatobis (ethylacetoacetate) aluminum, and the like.
Examples of the organometallic compound (2) and its partial hydrolyzate include tri-n-butoxy (ethylacetoacetate) zirconium, di-i-propoxybis (acetylacetonato) titanium, di-i-propoxy (ethylacetoacetate). Aluminum, tris (ethyl acetoacetate) aluminum, and partial hydrolysates of these compounds are preferred.

Moreover, as a specific example of an organotin compound,
_{(C 4 H 9) 2 Sn} (OCOC 11 H 23) 2,
_{(C 4 H 9) 2 Sn} (OCOCH = CHCOOCH 3) 2,
_{(C 4 H 9) 2 Sn} (OCOCH = CHCOOC 4 H 9) 2,
_{(C 8 H 17) 2 Sn} (OCOC 8 H 17) 2,
_{(C 8 H 17) 2 Sn} (OCOC 11 H 23) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOCH 3) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 4 H 9) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 8 H 17) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 16 H 33) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 17 H 35) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 18 H 37) 2,
_{(C 8 H 17) 2 Sn} (OCOCH = CHCOOC 20 H 41) 2,

(C ₄ H ₉ ) Sn (OCOC ₁₁ H ₂₃ ) ₃ ,
Carboxylic acid type organotin compounds such as (C ₄ H ₉ ) Sn (OCONa) ₃ ;
_{(C 4 H 9) 2 Sn} (SCH 2 COOC 8 H 17) 2,
_{(C 4 H 9) 2 Sn} (SCH 2 CH 2 COOC 8 H 17) 2,
_{(C 8 H 17) 2 Sn} (SCH 2 COOC 8 H 17) 2,
_{(C 8 H 17) 2 Sn} (SCH 2 CH 2 COOC 8 H 17) 2,
_{(C 8 H 17) 2 Sn} (SCH 2 COOC 12 H 25) 2,
_{(C 8 H 17) 2 Sn} (SCH 2 CH 2 COOC 12 H 25) 2,
_{(C 4 H 9) Sn (} SCOCH = CHCOOC 8 H 17) 3,
_{(C 8 H 17) Sn (} SCOCH = CHCOOC 8 H 17) 3,

Mercaptide-type organotin compounds such as
(C ₄ H ₉ ) ₂ Sn = S, (C ₈ H ₁₇ ) ₂ Sn = S,

等のスルフィド型有機スズ化合物；
（Ｃ_４Ｈ_９）ＳｎＣｌ_３ 、
（Ｃ_４Ｈ_９）_２ＳｎＣｌ_２ 、
（Ｃ_８Ｈ_１７）_２ＳｎＣｌ_２、

Sulfide type organotin compounds such as
(C ₄ H ₉ ) SnCl ₃ ,
(C ₄ H ₉ ) ₂ SnCl ₂ ,
(C ₈ H ₁₇ ) ₂ SnCl ₂ ,

等のクロライド型有機スズ化合物；
（Ｃ_４Ｈ_９）_２ ＳｎＯ、 （Ｃ_８Ｈ_１７）_２ ＳｎＯ等の有機スズオキサイドや、これらの有機スズオキサイドとシリケート、マレイン酸ジメチル、マレイン酸ジエチル、フタル酸ジオクチル等のエステル化合物との反応生成物等を挙げることができる。

Chloride-type organotin compounds such as
Reaction of organic tin oxides such as (C ₄ H ₉ ) ₂ SnO, (C ₈ H ₁₇ ) ₂ SnO, and these organic tin oxides with silicates, dimethyl maleate, diethyl maleate, dioctyl phthalate, etc. Product etc. can be mentioned.

The amount of the hydrolysis / condensation catalyst used is usually 0.01-5 parts by weight, preferably 100 parts by weight in total of the component (a) (completely hydrolyzed / condensed product) and the component (b), preferably 0.1 to 5 parts by weight, more preferably 0.1 to 3 parts by weight. If the amount of the hydrolysis / condensation catalyst used is less than 0.01 parts by weight, the hydrolysis / condensation reaction of the component (a) may be insufficient, while if it exceeds 5 parts by weight, the component (A) is stored. There is a tendency that stability is lowered and cracks are likely to occur in the coating film.

Examples of the radical polymerization initiator used for the preparation of the specific composite particles include persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, hydrogen peroxide, tert-butyl hydroperoxide, and tert-butyl peroxy. Water-soluble initiators such as maleic acid, succinic peroxide, 2,2′-azobis (2-N-benzylamidino) propane hydrochloride;
Oil-soluble initiators such as benzoyl peroxide, cumene hydroperoxide, diisopropyl peroxydicarbonate, cumyl peroxyneodecanoate, cumyl peroxy octoate, azobisisobutyronitrile;
Examples thereof include redox initiators that are used in combination with a reducing agent such as acidic sodium sulfite, Rongalite, and ascorbic acid.
Among these radical polymerization initiators, a water-soluble initiator is preferable from the viewpoint of polymerization stability.

The amount of the radical polymerization initiator used is usually 0.01 to 5 parts by weight, preferably 0 with respect to 100 parts by weight in total of the component (a) (completely hydrolyzed / condensed product) and the component (b). 0.05 to 4 parts by weight, more preferably 0.1 to 3 parts by weight. If the amount of the radical polymerization initiator used is less than 0.01 parts by weight, the radical polymerization reaction may be deactivated in the middle. On the other hand, if it exceeds 5 parts by weight, the weather resistance of the coating film may be insufficient. .
In the preparation of the specific composite particles, the mixture of the components (a), (b) and (c) is emulsified under the temperature and pressure at which the mixture of components (a) to (c) is liquid. What is necessary is just to stir so that it may become a uniform mixed state visually.
By this emulsification, each component is uniformly mixed and emulsified, and the hydrolysis / condensation reaction of component (a) proceeds. In the condensation reaction, when component (a) is a mixture of organosilane (1) and its hydrolyzate or partial condensate, the reaction between organosilane (1) and its hydrolyzate or partial condensate is the same. In addition to the condensation, organosilane (1) and its hydrolyzate or partial condensate may condense independently, respectively, in addition to the cocondensation of the hydrolyzate and the partial condensate, the hydrolyzate and In some cases, the partial condensates may be condensed alone.
In addition, when the emulsion is refined, the average particle size of the emulsion is usually 0.5 μm or less, preferably 0 by treating with mechanical or physical means such as a high-pressure homogenizer, homomixer, or ultrasonic wave. 0.05 to 0.2 μm. If the average particle size of the emulsion exceeds 0.5 μm, the water resistance of the coating film may be insufficient.

In the radical polymerization of the component (b), a part of the condensation reaction of the component (a) and the radical polymerization of the component (b) proceed simultaneously in a state where the emulsion is made fine. As a result, the polyorganosiloxane and the acrylic polymer form an interpenetrating network structure. In addition, since the polymers are entangled with each other in a solvent-free state in the emulsion particles, the degree of freedom of silanol groups rich in condensation reactivity in the component (a) is limited, the condensation reaction is suppressed, and good storage stability is achieved. Achieved. The reaction conditions for the radical polymerization of component (b) are such that the temperature is usually 25 to 100 ° C, preferably 40 to 90 ° C, and the reaction time is usually 0.5 to 15 hours, preferably 1 to 8 hours. .
When the component (a) and / or the component (b) used for the preparation of the specific composite particle has an acidic group such as a carboxyl group or a carboxylic anhydride group, at least one basic compound is added after radical polymerization. By adding and adjusting the pH, and when each of the components has a basic group such as an amino group or an amineimide group, after radical polymerization, at least one acidic compound is added to adjust the pH. By adjusting, when each of the above components further has both an acidic group and a basic group, at least one basic compound or acidic compound is added after radical polymerization according to the ratio of these groups. In any case, by adjusting the pH, the hydrophilicity of the obtained specific composite particles can be increased, the dispersibility can be improved, and the specific composite particles during storage can be improved. It is possible to suppress the progress of the condensation reaction of the silanol groups.

Examples of the basic compound include amines such as ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, dimethylaminoethanol;
Examples thereof include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.
Examples of the acidic compound include inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, and nitric acid; formic acid, acetic acid, propionic acid, lactic acid, oxalic acid, citric acid, adipic acid, maleic acid, fumaric acid, and itaconic acid. The organic acids can be mentioned. Moreover, radically polymerizable unsaturated carboxylic acids such as (meth) acrylic acid contained in the component (b) also contribute to pH adjustment.
The pH of the aqueous dispersion of specific composite particles after this pH adjustment is usually 5 to 10, preferably 6 to 8.

The dispersion state of the aqueous dispersion of specific composite particles obtained in this manner can be in the form of particles or sol. The average particle diameter of the specific composite particles in the component (A) is usually 0.01 to 0.5 μm, preferably 0.05 to 0.2 μm.
Moreover, the solid content concentration of the specific composite particles in the component (A) is usually 10 to 60% by weight, preferably 20 to 50% by weight. This solid content concentration is usually adjusted by the amount of water as an aqueous medium.
The aqueous medium in the aqueous dispersion of specific composite particles consists essentially of water, but contains an alcohol produced by hydrolysis of the alkoxy group in component (a). The alcohol content in the aqueous dispersion of the specific composite particles is preferably 0.1 to 2% by weight, more preferably 0.2 to 2% by weight, especially the alcohol content in the component (A) of the present invention. Preferably, the range is 0.5 to 2% by weight. When the alcohol content in the aqueous dispersion of the specific composite particles is too large, for example, by treating in the same manner as the method for reducing the alcohol content in the final aqueous resin dispersion described later, the alcohol content is reduced. A preferable range can be set.

-Adjustment of alcohol content-
The aqueous medium in the aqueous resin dispersion of the present invention consists essentially of water, but contains an alcohol produced by hydrolysis of the alkoxy group in component (a). The alcohol content is preferably 2% by weight or less. When the alcohol content in the aqueous dispersion exceeds 2% by weight, the anti-checking property may be insufficient, and the method for bringing the alcohol content in the aqueous resin dispersion of the present invention within the desired range is described below. For example, after the radical polymerization of the component (b), after adjusting the pH as necessary, if the alcohol content is too high, a treatment such as addition of an aqueous medium or separation and removal of the alcohol is performed. In this case, from the viewpoint of the stability of the aqueous resin dispersion, it is preferable to reduce the alcohol content after pH adjustment.
Examples of the method for separating and removing the alcohol in the aqueous resin dispersion include the following methods.
(I) Method using an evaporator A method in which alcohol is distilled off by stirring under heating or normal temperature while blowing a gas such as air or nitrogen into an aqueous resin dispersion under reduced pressure or normal pressure. As an apparatus used in this method, a four-necked flask for polymerization can be used in the laboratory, and a polymerization reactor can be industrially used.
(Ii) Method by centrifugal thin film evaporator A method in which the conical heat transfer surface is rotated, and the aqueous resin dispersion is thinned by centrifugal force to evaporate the alcohol. As an apparatus used for this method, an evaporator can be used in the laboratory, and industrially, “Evapor” manufactured by Okawara Seisakusho or “centrifugal molecular distillation apparatus” manufactured by Japanese vehicle.
(Iii) Method using an external circulation apparatus A method of evaporating alcohol by flowing an aqueous resin dispersion and a heating medium alternately in a flow path formed by overlapping corrugated plates. As an apparatus used in this method, “Bubbles” manufactured by Nisso Engineering can be mentioned industrially.
(Iv) Method using a falling film type apparatus A method of evaporating alcohol by flowing an aqueous resin dispersion in a thin film form from the top of a heating tube group.
(V) Method by stirring thin film apparatus A method of evaporating alcohol by thinning the aqueous resin dispersion with a stirring blade installed in a cylindrical heating tube. As an apparatus used for this method, industrially, “Wiperen” and “Exeva” manufactured by Shinko Pantech can be exemplified.

Among these methods, a method using an evaporator is preferable in that an additional device is not required, or a method using a centrifugal thin film evaporator and a method using an external circulation device are preferable in terms of industrial production efficiency. . In addition, the solid content concentration of the aqueous resin dispersion can be increased by volatilizing or evaporating water at the same time as the separation and removal of the alcohol within a range not impairing the stability of the aqueous resin dispersion. Even when the alcohol content is within a desirable range, the solid content concentration of the aqueous resin dispersion may be adjusted by adding an aqueous medium, volatilization or evaporation of water, or the like.

-Additive component-
The water-based resin dispersion of the present invention can contain an ultraviolet absorber and / or a light stabilizer. The ultraviolet absorber and / or light stabilizer is preferably substantially insoluble in water. Here, “substantially insoluble in water” means that the solubility in water is 0.1% by weight or less, preferably 0.01% by weight or less. By using such UV absorbers and / or light stabilizers, when the coating film is exposed outdoors, the UV absorbers and / or light stabilizers will not flow out due to rain, and good weather resistance will be maintained for a long time. it can.

The ultraviolet absorber and / or light stabilizer is preferably added before the radical polymerization of the component (b), preferably at the time of emulsification of the components (a) to (c). Even water-insoluble UV absorbers and / or light stabilizers that cannot be introduced into the particles can be introduced into the monomer oil droplets that are the precursors of the specific composite particles, during the emulsion refinement stage, As a result, a coating film excellent in weather resistance can be obtained.
In the aqueous resin dispersion of the present invention, the ultraviolet absorber and / or the light stabilizer are substantially separated from the specific composite particles, and the ultraviolet absorber and / or the light stabilizer are contained in the specific composite particles. Any state that is present in a dispersed state or that contains a radical polymerizable ultraviolet absorber and / or light stabilizer in the component (b) and is a structural unit of an acrylic polymer constituting the specific composite particle It can also take.

The ultraviolet absorber and / or light stabilizer is not particularly limited, and examples thereof include organic ultraviolet absorbers such as oxalic anilide, salicylic acid, benzophenone, triazine, benzotriazole, and cyanoacrylate. ;
Any of those having an ultraviolet absorbing action or a light stabilizing action used for organic nickel compounds, hindered amine light stabilizers, paints, synthetic rubbers, synthetic resins, synthetic fibers and the like may be used.

Examples of ultraviolet absorbers and light stabilizers are given below, but the manufacturer name and product name are shown in part.
Examples of organic ultraviolet absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, pn-octylphenyl salicylate, 2,4-dihydroxyphenyl salicylate, and p-methacryloyloxyphenyl salicylate as a radical polymerizable monomer. Salicylic acid UV absorbers such as

2,4-dihydroxybenzophenone [BASF Japan, UVINUL 3000], 2-hydroxy-4-methoxybenzophenone [BASF Japan, UVINUL M-40], 2-hydroxy-4-n-octyloxybenzophenone [BASF Japan UVINUL 408], 2-hydroxy-4-n-dodecyloxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone [manufactured by BASF Japan Ltd.] , UVINUL 3049], 2-hydroxy-4-methoxy-5-sulfobenzophenone [manufactured by BASF Japan, UVINUL MS-40], bis (2-methoxy-4-hydroxy-5-benzoylphenyl) methane, 2,2 ', 4,4'-tetrahydroxybenzophenone [manufactured by BASF Japan, UVINUL 3050], and a radical polymerizable monomer such as 2-hydroxy-4-methacryloyloxybenzophenone, a benzophenone-based ultraviolet absorber;

2- [4-{(2-hydroxy-3-n-dodecyloxypropyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine and 2- [4 -Mixture with {(2-hydroxy-3-n-tridodecyloxypropyl) oxy} -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -s-triazine [TINUVIN manufactured by BASF Japan 400], triazine ultraviolet absorbers such as 2- (4-i-octyloxy-2-hydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -s-triazine;

2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) Benzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) -5-chloro Benzotriazole, 2- (2-hydroxy-3,5-di-tert-amylphenyl) -2H-benzotriazole [manufactured by BASF Japan, TINUVIN 328], 2- (2-hydroxy-4-n-octyloxyphenyl) Benzotriazole, 2- [2-hydroxy-3- (3,4,5,6-tetrahydro Tarimidomethyl) -5-methylphenyl] benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] 2,2′-methylenebis [4-ethanol-6- (2H-benzotriazol-2-yl) phenol],

i-octyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionate [manufactured by BASF Japan, TINUVIN 384-2], 2- [2-hydroxy- 3,5-di (1,1-dimethylbenzyl) phenyl] -2H-benzotriazole [manufactured by BASF Japan, TINUVIN 900], 2- [2-hydroxy-3-dimethylbenzyl-5- (1,1,3 , 3-tetramethylbutyl) phenyl] -2H-benzotriazole [manufactured by BASF Japan, TINUVIN 928], methyl-3- [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4- Hydroxyphenyl] condensation product of propionate and polyethylene glycol [manufactured by BASF Japan, TI UVIN 1130], 3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propanol, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) ) -5-chlorobenzotriazole aqueous dispersion (ADEKA, ADK STAB LX-301),

As radically polymerizable monomers, 2- (2-hydroxy-3-methacryloyloxyphenyl) -2H-benzotriazole, 2- (2-hydroxy-4-methacryloyloxyphenyl) -2H-benzotriazole, 2- (2-hydroxy -5-methacryloyloxyphenyl) -2H-benzotriazole, 2- (2-hydroxyphenyl) -5-methacryloyloxy-2H-benzotriazole, 2- (2-hydroxy-3-methacryloyloxy-5-methylphenyl)- 2H-benzotriazole, 2- (2-hydroxy-5-methacryloyloxy-3-methylphenyl) -2H-benzotriazole, 2- (2-hydroxy-3-methylphenyl) -5-methacryloyloxy-2H-benzotriazole , 2- (2-H Roxy-5-methylphenyl) -5-methacryloyloxy-2H-benzotriazole, 2- (2-hydroxy-3-methacryloyloxy-5-tert-butylphenyl) -2H-benzotriazole, 2- (2-hydroxy- 5-methacryloyloxy-3-tert-butylphenyl) -2H-benzotriazole, 2- (2-hydroxy-3-tert-butylphenyl) -5-methacryloyloxy-2H-benzotriazole, 2- (2-hydroxy- 5-tert-butylphenyl) -5-methacryloyloxy-2H-benzotriazole,

2- [2-hydroxy-3- (2-methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2-hydroxy-4- (2-methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2-hydroxy-5- (2-methacryloyloxyethyl) phenyl] -2H-benzotriazole [manufactured by Otsuka Chemical, RUVA-93], 2- (2-hydroxyphenyl) -5- (2-methacryloyloxyethyl)- 2H-benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-methylphenyl] -2H-benzotriazole, 2- [2-hydroxy-5- (2-methacryloyloxyethyl)- 3-methylphenyl] -2H-benzotriazole, 2- (2-hydroxy-3 Methylphenyl) -5- (2-methacryloyloxyethyl) -2H-benzotriazole, 2- (2-hydroxy-5-methylphenyl) -5- (2-methacryloyloxyethyl) -2H-benzotriazole, 2- [ 2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] -2H-benzotriazole, 2- [2-hydroxy-5- (2-methacryloyloxyethyl) -3-tert-butylphenyl ] -2H-benzotriazole, 2- (2-hydroxy-3-tert-butylphenyl) -5- (2-methacryloyloxyethyl) -2H-benzotriazole, 2- (2-hydroxy-5-tert-butylphenyl) ) -5- (2-Methacryloyloxyethyl) -2H-benzotri Orres,

2- (2-hydroxy-3-methacryloylaminophenyl) -2H-benzotriazole, 2- (2-hydroxy-4-methacryloylaminophenyl) -2H-benzotriazole, 2- (2-hydroxy-5-methacryloylaminophenyl) ) -2H-benzotriazole, 2- (2-hydroxyphenyl) -5-methacryloylamino-2H-benzotriazole, 2- (2-hydroxy-3-methacryloylamino-5-methylphenyl) -2H-benzotriazole, 2 -(2-hydroxy-5-methacryloylamino-3-methylphenyl) -2H-benzotriazole, 2- (2-hydroxy-3-methylphenyl) -5-methacryloylamino-2H-benzotriazole, 2- (2- Hydroxy-5-methylphenyl) 5-methacryloylamino-2H-benzotriazole, 2- (2-hydroxy-3-methacryloylamino-5-tert-butylphenyl) -2H-benzotriazole, 2- (2-hydroxy-5-methacryloylamino-3-tert -Butylphenyl) -2H-benzotriazole, 2- (2-hydroxy-3-tert-butylphenyl) -5-methacryloylamino-2H-benzotriazole, 2- (2-hydroxy-5-tert-butylphenyl)- Benzotriazole ultraviolet absorbers such as 5-methacryloylamino-2H-benzotriazole;
Cyanoacrylates such as 2-ethylhexyl-2-cyano-3,3′-diphenyl acrylate [manufactured by BASF Japan, UVINUL 3039], ethyl-2-cyano-3,3′-diphenyl acrylate [manufactured by BASF Japan, UVINUL 3035] An ultraviolet absorber etc. can be mentioned.

Moreover, as a hindered amine light stabilizer, for example,
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 1- (methyl) -8- (1, 2,2,6,6-pentamethyl-4-piperidyl) sebacate [BASF Japan, TINUVIN 292], bis (2,2,6,6-tetramethyl-1-n-octyloxy-4-piperidyl) ) Sebacate [manufactured by BASF Japan, TINUVIN 123], bis (1,2,2,6,6-pentamethyl-4-piperidyl)-[{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl } Methyl] butyl malonate [manufactured by BASF Japan, TINUVIN 144], TINUVIN 111FD [trade name, manufactured by BASF Japan], tetraxy (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate [manufactured by ADEKA, ADK STAB LA-57], tetraxy (1,2,2,6,6 -Pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate [manufactured by ADEKA, ADK STAB LA-52],

1,2,2,6,6-pentamethyl-4-piperidyl / tridecyl mixed ester of 1,2,3,4-butanetetracarboxylic acid (manufactured by ADEKA, Adekastab LA-62), Adekastab LA-67 [trade name, ADEKA], ADK STAB LA-63P (trade name, manufactured by ADEKA), ADK STAB LA-68LD [trade name, manufactured by ADEKA], 1- [2- {3- (3,5-di-tert-butyl-4-hydroxy Phenyl) propionyloxy} ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine [Sankyo, Sanol LS -2626], 4-benzoyloxy-2,2,6,6-tetramethylpiperidine [Sankyo LS-744], 8- Cetyl-3-n-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione [Sankyo LS Sanyo LS-440], poly [ {6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino } Hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] [Sankyo LS-944], 1,2,3,4-butanetetracarboxylic acid 1,2, An aqueous dispersion of 2,6,6-pentamethyl-4-piperidyl / tridecyl mixed ester [manufactured by ADEKA, Adeka Stab LX-332],

As radically polymerizable monomers, 1,2,2,6,6-pentamethyl-4-piperidyl acrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate [manufactured by ADEKA, ADK STAB LA-82], 2 , 2,6,6-tetramethyl-4-piperidyl acrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate [manufactured by ADEKA, ADK STAB LA-87], 1,2,2,6,6- Pentamethyl-4-iminopiperidyl methacrylate, 2,2,6,6-tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1 2,2,6,6-pentamethyl-4-piperidyl methacrylate and the like.

Of these ultraviolet absorbers and light stabilizers, triazine-based, benzotriazole-based or cyanoacrylate-based organic ultraviolet absorbers and hindered amine-based light stabilizers, which are non-polymerizable or radically polymerizable, are preferable. The said ultraviolet absorber and light stabilizer component can be used individually or in mixture of 2 or more types. In addition, the use of a liquid compound having no melting point of −5 ° C. or lower as the ultraviolet absorber and / or light stabilizer gives the coating film flexibility at a low temperature, which is favorable. In addition to excellent weather resistance, it is possible to impart good frost resistance.
Furthermore, when the ultraviolet absorber and / or the light stabilizer have radical polymerizability, excellent weather resistance can be maintained over a long period of time as a result of suppressing bleeding out of the component from the coating film.
The said ultraviolet absorber and light stabilizer can be used individually or in mixture of 2 or more types.

The compounding amount of the ultraviolet absorber and / or the light stabilizer is usually 0.1 to 10 weights per 100 parts by weight in total of the component (a) (completely hydrolyzed / condensed product) and the component (b). Parts, preferably 0.2 to 8 parts by weight, more preferably 0.5 to 5 parts by weight. When the blending amount is less than 0.1 parts by weight, the effect of improving the weather resistance tends to be reduced. On the other hand, when it exceeds 10 parts by weight, the surface of the coating film becomes tacky and easily becomes dirty, and the blocking resistance is improved. May decrease.

Moreover, the low molecular weight poly (meth) acrylate whose Mw is 1,000-10,000 normally, Preferably it is 1,000-5,000 can be mix | blended with the aqueous resin dispersion of this invention.
The low molecular weight poly (meth) acrylate is desirably added before the radical polymerization of the component (b), preferably when the components (a) to (c) are emulsified, so that the component (b) has a low molecular weight poly ( Radical polymerization is carried out in the presence of meth) acrylate, and a coating film having excellent blocking resistance can be obtained without reducing frost resistance.

The low molecular weight poly (meth) acrylate may be, for example, 2 (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2 -In the presence of a chain transfer agent such as dodecyl mercaptan, if necessary, together with a radical polymerizable monomer having a functional group such as hydroxyethyl (meth) acrylate, (meth) acrylic acid, (meth) acrylate having a siloxane group, It can be produced by solution polymerization. Commercially available low molecular weight poly (meth) acrylates include “Act Flow UT-300” (Mw = 3,800), “Act Flow UMB-1001” (Mw = 1,500), “Act Flow” manufactured by Soken Chemical. UME-1001 "(Mw = 2000)," Act Flow CBL-3098 "(Mw = 4,000), and the like.
When the Mw of the low molecular weight poly (meth) acrylate is less than 1,000, the effect of improving the blocking resistance tends to be reduced. On the other hand, when the Mw exceeds 10,000, the particle diameter becomes large, and the transparency of the coating film is increased. There is a tendency to decrease.
Low molecular weight poly (meth) acrylates can be used alone or in admixture of two or more.

The blending amount of the low molecular weight poly (meth) acrylate is usually 0.1 to 10 parts by weight with respect to 100 parts by weight in total of the component (a) (completely hydrolyzed / condensed product) and the component (b). Preferably it is 0.2-5 weight part, More preferably, it is 0.5-3 weight part. If the blending amount is less than 0.1 parts by weight, the effect of improving the blocking resistance tends to be reduced. On the other hand, if it exceeds 10 parts by weight, the particle diameter tends to increase and the transparency of the coating film tends to decrease. is there.

In addition, the aqueous resin dispersion of the present invention includes a polymerizable unsaturated group capable of radical copolymerization with the component (b) and / or a group capable of forming a siloxane bond by co-condensing with the component (a) (for example, alkoxy A silane coupling agent having a silyl group or the like can be blended.
When the aqueous resin dispersion of the present invention contains this silane coupling agent, the hybrid property of the acrylic component and the silane component constituting the aqueous resin dispersion is improved. Etc. can be further improved.

When the silane coupling agent is blended, the components (a) to (c) may be mixed with the component (a) and / or the component (b) before emulsifying the components (a) to (c). Although it may be added at the time of hydrolysis / condensation reaction, may be added at the time of radical polymerization of component (b), or may be added after the production of the aqueous resin dispersion, emulsions of components (a) to (c) It is preferable to mix with (a) component and / or (b) component before conversion.

As a specific example of the silane coupling agent,
_{CH 2 = CHSi (CH 3)} (OCH 3) 2, CH 2 = CHSi (OCH 3) 3,
Vinyl group-containing silane coupling agents such as CH ₂ = CHSi (CH ₃ ) Cl ₂ , CH ₂ = CHSiCl ₃ ;
_{CH 2 = CHCOO (CH 2)} 2 Si (CH 3) (OCH 3) 2,
_{CH 2 = CHCOO (CH 2)} 2 Si (OCH 3) 3,
_{CH 2 = CHCOO (CH 2)} 3 Si (CH 3) (OCH 3) 2,
_{CH 2 = CHCOO (CH 2)} 3 Si (OCH 3) 3,
_{CH 2 = CHCOO (CH 2)} 2 Si (CH 3) Cl 2,
CH ₂ = CHCOO (CH ₂ ) ₂ SiCl ₃ ,

_{CH 2 = CHCOO (CH 2)} 3 Si (CH 3) Cl 2,
CH ₂ = CHCOO (CH ₂ ) ₃ SiCl ₃ ,
_{CH 2 = C (CH 3)} COO (CH 2) 2 Si (CH 3) (OCH 3) 2,
_{CH 2 = C (CH 3)} COO (CH 2) 2 Si (OCH 3) 3,
_{CH 2 = C (CH 3)} COO (CH 2) 3 Si (CH 3) (OCH 3) 2,
_{CH 2 = C (CH 3)} COO (CH 2) 3 Si (OCH 3) 3,
_{CH 2 = C (CH 3)} COO (CH 2) 2 Si (CH 3) Cl 2,
_{CH 2 = C (CH 3)} COO (CH 2) 2 SiCl 3,
_{CH 2 = C (CH 3)} COO (CH 2) 3 Si (CH 3) Cl 2,
(Meth) acryloxy group-containing silane coupling agents such as CH ₂ ═C (CH ₃ ) COO (CH ₂ ) ₃ SiCl ₃ can be mentioned.
These silane coupling agents can be used alone or in admixture of two or more.

The amount of the silane coupling agent is usually 20 parts by weight or less, preferably 10 parts by weight or less, based on 100 parts by weight of the total of the component (a) (completely hydrolyzed / condensed product) and the component (b). It is. So far synthesis method

  (A) component of this invention is 10-35 mass% of a composition in conversion of solid content, Preferably it is preferable that it is 15-35 mass%.

(B) As a metal oxide particle, the particle | grains which consist of a titanium oxide, a zinc oxide, and a cerium oxide can be mentioned.
The number average particle diameter of the metal oxide particles is 0.02 to 2 μm, preferably 0.02 to 1 μm.
These metal oxide particles may be used alone or in combination of two or more.
(B) The usage-amount of a component is 10-200 weight part normally with respect to 100 weight part of (A) component.

  Examples of the UV absorber include benzotriazole UV absorbers, triazine UV absorbers, and benzophenone UV absorbers.

As a benzotriazole ultraviolet absorber,
As a commercial item, the said benzotriazole type | system | group ultraviolet absorber can be mentioned, for example, It can be used as it is disperse | distributed to water as it is, using an emulsifier as needed. In addition, New Coat UVA-204W (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.), SE-2538E (trade name, manufactured by Taisei Fine Chemical Co., Ltd.) and the like can be exemplified as water-based benzotriazole ultraviolet absorbers.

Examples of the triazine-based ultraviolet absorber include the above-mentioned triazine-based ultraviolet absorber, and the triazine-based ultraviolet absorber can be used by using an emulsifier as needed or dispersed in water as it is. In addition, TINUVIN 477-DW (trade name, manufactured by BASF Japan), Shine Guard TA-22 (trade name, manufactured by Senka) and the like can be mentioned.

As benzophenone UV absorbers,
The benzophenone-based ultraviolet absorber can be used by using an emulsifier, if necessary, or dispersed in water as it is.
The usage-amount of a ultraviolet absorber is 5 to 25 weight% of a normal composition normally in conversion of solid content, Preferably it is 5 to 20 weight%.

  (C) As the aqueous medium, water or a mixed solvent of water and a water-soluble organic solvent such as alcohol can be used. In the case of using a mixed solvent of water and a water-soluble organic solvent, the ratio of the water-soluble organic solvent is preferably 10% by mass or less based on the entire aqueous medium.

In addition to the above components (A) to (C), the composition used in the present invention may contain a surfactant, a crosslinking agent, a dispersant, a thickener, a film forming aid, an antiblocking agent, and the like as necessary. May be included.
Examples of the surfactant include a fluorine-based surfactant and a silicone-based surfactant.
Examples of the crosslinking agent include hydrazide crosslinking agents and oxazoline crosslinking agents.
Examples of the dispersant include dispersants such as polycarboxylate, polyphosphate, polyacrylate, polyamide ester salt, and polyethylene glycol.
Examples of the thickener include celluloses such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and thickeners such as castor oil derivatives, ferrosilicates, and polycarboxylic acid-based thickeners. it can.
As film forming aids, methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-hexyl alcohol, n-octyl alcohol, ethylene glycol, diethylene glycol , Triethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diacetone alcohol, texanol and the like.

Examples of the antiblocking agent include silica particles, calcium carbonate, zeolite, talc, and polystyrene particles.

  In the present invention, as a method of applying the composition to the transparent substrate, a known application method can be used, and examples thereof include a dipping method, a coater method, and a printing method.

In the present invention, the protective layer is formed by applying the composition on a transparent substrate and drying it. It is preferable to heat the coating film after applying the composition. The heating temperature is usually 80 to 160 ° C., and the heating time is about 10 seconds to 20 minutes.
The thickness of the protective layer obtained in the present invention is usually 3 to 8 μm.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
In the following, “%” indicates “% by weight” unless otherwise specified, and “parts” indicates “parts by weight” unless otherwise specified. The particle size of the dispersion was measured using a concentrated particle size analyzer FPAR-1000 manufactured by Otsuka Electronics.

(Synthesis Example 1)
Each reaction component shown in Table 1 (excluding acrylic acid and potassium persulfate) was stirred for 10 minutes at room temperature to emulsify, then 80% aqueous acrylic acid solution was added, and stirring was continued at 40 ° C. for 2 hours. Hydrolysis / condensation reaction was performed. Thereafter, the emulsion was refined at a pressure of 70 MPa using a high-pressure homogenizer (trade name: Microfluidizer M110Y) manufactured by Mizuho Industries. Thereafter, the obtained emulsion was put into a four-necked separable flask, and the atmosphere was purged with nitrogen while stirring. Then, potassium persulfate was added as a 3.5% aqueous solution as a radical polymerization initiator, and polymerization was performed at 75 ° C. for 4 hours. Thereafter, the pH of the reaction system was adjusted to 7.0 with a 10% aqueous ammonia solution. Thereafter, one neck of the four-necked separable flask is released, nitrogen is blown from the other one at a rate of 50 liters per minute, the temperature is raised again to 80 ° C. with stirring, and alcohol is retained for 4 hours. To obtain an aqueous resin dispersion having a solid content concentration exceeding 42%. Thereafter, water was added to this aqueous resin dispersion to adjust the solid content concentration to 41%, whereby Dispersion 1 was obtained.
This aqueous resin dispersion had an acrylic polymer Tg of 25 ° C. and an average particle diameter of 0.1 μm.

(Synthesis Example 2)
Dispersion 2 was obtained in the same manner as in Synthesis Example 1 except that each reaction component shown in Synthesis Example 2 in Table 1 was used.
(Synthesis Example 3)
Dispersion 3 was obtained in the same manner as in Synthesis Example 1 except that each reaction component shown in Synthesis Example 3 in Table 1 was used.
(Synthesis Example 4)
Dispersion 4 was obtained in the same manner as in Synthesis Example 1 except that each reaction component shown in Synthesis Example 4 in Table 1 was used.
(Synthesis Example 5)
Each reaction component shown in Table 1 was emulsified by stirring at room temperature for 2 hours. Subsequently, the emulsion was refined at a pressure of 70 MPa using a high-pressure homogenizer (trade name: Microfluidizer M110Y) manufactured by Mizuho Industry. The obtained emulsion was put into a four-necked separable flask, purged with nitrogen while stirring, and then subjected to a condensation reaction at 70 ° C. for 3 hours. Thereafter, one of the four-necked separable flasks is opened, nitrogen is blown from the other one at a rate of 50 liters per minute, the temperature is raised again to 80 ° C. with stirring, and alcohol is retained for 1 hour. To obtain a dispersion 6 having a solid concentration of 25%.

Examples 1-8 and Comparative Examples 1-3 were implemented with the composition shown in Table 2. Details are shown below.
Example 1
(1) Production of composition Dispersion 1, AF white E-3D (titanium oxide aqueous dispersion) manufactured by Dainichi Seika Kogyo, SN Dispersant 5027 (dispersant) manufactured by San Nopco, New Coat UVA-204W manufactured by Shin-Nakamura Chemical Co., Ltd. , Sinca Shine Guard TA-22 (all UV absorbers), ethylene glycol monobutyl ether (film forming aid), Nippon Shokubai Epocross WS-700 (oxazoline-based crosslinking agent) are added with stirring, and stirred for 15 minutes. After continuing, Rohm and Haas Primal ASE60 (thickener) and water were added with stirring to obtain Composition 1 having a solid content of 40%.
(2) The composition obtained in (1) above was applied to polyethylene terephthalate having a thickness of 125 μm by a bar coater # 12 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.

(Example 2)
As shown in Table 2, a solar cell protective sheet was obtained in the same manner as in Example 1 except that the component A was the dispersion 2.
(Example 3)
As shown in Table 2, a solar cell protective sheet was obtained in the same manner as in Example 1 except that the component A was the dispersion 3.
Example 4
(1) A composition 1 was obtained in the same manner as in Example 3.
(2) The composition obtained in (1) above was applied to polyethylene terephthalate having a thickness of 125 μm by a bar coater # 20, and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 8 μm. Got.
(Example 5)
(1) STR-60A-LP (titanium oxide) manufactured by Sakai Chemical, water, BYK Chemie BYK190 (dispersant) with the composition shown in Table 2 and put in a sealed container together with 0.2 mm zirconia beads, manufactured by Red Devil Shake for 2 hours using a paint shaker and remove the beads by filtration. The filtrate, dispersion 4, ethylene glycol monobutyl ether, and Epocros WS-700 were mixed and stirred at the composition shown in Table 2 to obtain a composition.
(2) The composition obtained in (1) above is applied to polyethylene terephthalate having a thickness of 125 μm by means of a bar coater # 20 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.
(Example 6)
A solar cell protective sheet was obtained in the same manner as in Example 5 except that NANOFINE 50A (zinc oxide) manufactured by Sakai Chemical Co., Ltd. was used.
(Example 7)
(1) Nidral P-10 manufactured by Taki Chemical Co., Ltd. (cerium oxide aqueous dispersion) was mixed and stirred with the composition shown in Table 2 to obtain a composition.
(2) The composition obtained in (1) above is applied to polyethylene terephthalate having a thickness of 125 μm by means of a bar coater # 20 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.
(Example 8)
(1) Dispersion 3, New Coat UVA-204W, Shine Guard TA-22, Epocross WS-700, and ethylene glycol monobutyl ether were mixed and stirred to obtain a composition.
(2) The composition obtained in (1) above was applied to polyethylene terephthalate having a thickness of 125 μm by a bar coater # 12 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.
(Comparative Example 1)
(1) Dispersion 5 (= acrylic emulsion AE373D manufactured by JSR), AF white E-3D, TINUVIN 384-2 (ultraviolet absorber) manufactured by BASF Japan, SN Dispersant 5027, ethylene glycol monobutyl ether, Epocros WS-700 is stirred. While stirring for 15 minutes, Primal ASE 60 was added with stirring to obtain a composition.
(2) The composition obtained in (1) above was applied to polyethylene terephthalate having a thickness of 125 μm by a bar coater # 12 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.
(Comparative Example 2)
(1) Dispersion 3, ethylene glycol monobutyl ether, and Epocros WS-700 were mixed and stirred to obtain a composition.
(2) The composition obtained in (1) above was applied to polyethylene terephthalate having a thickness of 125 μm by a bar coater # 12 and dried at 150 ° C. for 30 seconds to form a protective layer having a thickness of 5 μm. Got.
(Comparative Example 3)
As shown in Table 2, a solar cell protective sheet was obtained in the same manner as in Example 1 except that the component A was the dispersion 6.

[Evaluation]
About each solar cell protection sheet obtained as mentioned above, UV cut property, weather resistance, and initial stage adhesiveness were evaluated. The evaluation method is as follows.
(UV cut property)
The produced solar cell protective sheet was measured for transmittance in the wavelength range of 200 nm to 800 nm using an ultraviolet-visible spectrophotometer V-570 manufactured by JASCO Corporation, and evaluated by transmittance at 360 nm.
A: The transmittance at 360 nm is less than 1%,
○: The transmittance at 360 nm is 1% or more and less than 5%,
Δ: The transmittance at 360 nm is 5% or more and less than 10%.
X: The transmittance | permeability in 360 nm is 10% or more.

(Accelerated weather resistance)
The produced solar cell protective sheet is attached to a weather weather tester metal weather made by Daipura Wintes with KF-1 filter (trade name). (1) Irradiation intensity 75 mW / cm ² , temperature 63 ° C., relative humidity 50% 4 hours irradiation, (2) 10 seconds shower, (3) temperature maintained at 30 ° C. and 98% relative humidity for 4 hours, and (4) 10 seconds shower with 1 cycle of accelerated weathering test for 250 hours The gloss retention on the surface of the protective layer was measured and evaluated according to the following criteria. The gloss value was determined on the basis of the following criteria by measuring 60 ° gloss using a gloss meter Micro Gloss manufactured by BYK-Gardner, with an initial gloss value of 100.
A: Gloss retention is 95% or more,
○: Gloss retention is 80% or more and less than 95%,
Δ: Gloss retention is 60% or more and less than 80%,
X: Gloss retention is less than 60%.

(Initial adhesion)
The cross-cut method was performed in accordance with JIS K-5600-5-6. Using a specified cutter knife or cutter guide, create a total of 25 squares on the protective layer surface at 1 mm intervals in the vertical and horizontal directions, affix the specified cellophane tape, and from above the cellophane tape so that the coating film can be seen through It was rubbed with a finger, peeled off in the direction of 60 degrees on the surface of the resin layer, and evaluated according to the following criteria.
○: No peeling at the edge of the cut, or peeling that does not exceed 5% of the cross cut portion is observed only at the intersection of the cut (corresponding to the above JIS standard classifications 0 and 1)
Δ: peeling along the edge of the cut and / or at the intersection. It exceeds 5% of the crosscut portion but does not exceed 15%. (Category 2 equivalent)
X: The coating film is partially or totally peeled along the edge of the cut, and peeled off more than 15% of the cross cut portion. (Category 3-5 equivalent)

The contents of the abbreviations in Tables 1 and 2 are as follows.
X-40-9220: Hydrolysis / dehydration condensate oligomer of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical)
YF3800: polydimethylsiloxane having a silanol group at the terminal (made by Momentive)
Aqualon KH-10: Polyoxyethylene chain-containing reactive emulsifier whose terminal is sulfated (Daiichi Kogyo Seiyaku Co., Ltd.)
Emulgen 147: Polyoxyethylene lauryl ether (manufactured by Kao)
BLEMMER PE-200: Polyoxyethylene group-containing methacrylate (manufactured by NOF Corporation)
TINUVIN123: hindered amine light stabilizer (manufactured by BASF Japan)
TINUVIN384-2: Benzotriazole UV absorber (manufactured by BASF Japan)
UVA1: Newcoat UVA-204W (Benzotriazole UV absorber manufactured by Shin-Nakamura Chemical Co., Ltd.)
UVA2: Shine Guard TA-22 (Senka Triazine UV Absorber)
UVA3: TINUVIN 384-2 (described above)

（数値は重量部）

(Numbers are parts by weight)

数値は重量部（固形分換算）Ｃ成分の水には他成分の分散媒体としての水も含む

Numerical values are by weight (in terms of solid content) C component water includes water as a dispersion medium for other components

Claims (9)

  A transparent substrate is coated with a composition containing (A) particles containing polysiloxane (and acrylic polymer), (B) at least one selected from metal oxide particles and ultraviolet absorbers, and (C) an aqueous medium. And a step of forming a protective layer by drying, and a method for manufacturing a solar cell protective sheet. The polysiloxane in component (A) is represented by the following general formula (1)

(Wherein R ¹ represents a hydrogen atom or a monovalent organic group having 1 to 8 carbon atoms, a plurality of R ¹ may be the same as or different from each other, and R ² represents a hydrogen atom or a carbon number of 1 to 5) A plurality of R ² may be the same as or different from each other, and n is an integer of 2 to 4.)
The method for producing a solar cell protective sheet according to claim 1, wherein the product is a hydrolyzed condensate of organosilane represented by the formula:   2. The method for producing a solar cell protective sheet according to claim 1, wherein the metal oxide particles are selected from titanium oxide, zinc oxide, and cerium oxide.   2. The method for producing a solar cell protective sheet according to claim 1, wherein the ultraviolet absorber is selected from a benzotriazole-based ultraviolet absorber, a triazine-based ultraviolet absorber, and a benzophenone-based ultraviolet absorber.   2. The method for producing a solar cell protective sheet according to claim 1, wherein the content of the component (A) is 10 to 35% by mass of the composition.   2. The method for producing a solar cell protective sheet according to claim 1, wherein the content of the component (B) metal oxide is 10 to 200 parts by mass with respect to 100 parts by mass of the component (A).   The method for producing a solar cell protective sheet according to claim 1, wherein the protective layer has a thickness of 3 to 8 μm.   (A) Particles containing polysiloxane (and acrylic polymer), (B) At least one selected from metal oxide particles and ultraviolet absorbers, and (C) a solar cell protective layer comprising an aqueous medium Forming composition.   The solar cell protection sheet manufactured by the method in any one of Claims 1-8.