JP2019177651A - Laminate coat - Google Patents

Abstract

An object of the present invention is to provide a laminate coating film capable of maintaining the adhesion between a photocatalyst layer and an intermediate layer for a long period of time. Kind Code: A1 A multilayer coating film comprising a base material, an intermediate layer formed on the base material, and a photocatalyst layer formed on the intermediate layer, wherein the intermediate layer has an inorganic polymer segregated on the surface. The photocatalyst layer includes photocatalyst particles and inorganic oxide particles. The resin composite has a core-shell structure, and the shell has a thickness of 5.0 nm or more. The resin composite contains a fluoropolymer, a (meth) acrylic polymer, and an inorganic polymer. The inorganic polymer is a polysiloxane. The fluoropolymer contains vinylidene fluoride units and at least one fluoroolefin unit selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene. [Selection diagram] None

Description

The present disclosure relates to a laminate coating film suitable for use in exterior materials such as buildings.

Exterior building materials using photocatalysts such as titanium oxide have been widely used in recent years. The active species generated when the photocatalyst is excited by light energy decomposes various organic substances, or hydrophilizes the surface of the member on which the surface layer containing the photocatalyst particles is formed, so that dirt adhered to the surface can be easily removed with water. It can be washed away.

By the way, although a fluororesin known for its high weather resistance is often used for building materials, there is a problem that it is difficult to realize a laminate coating film with a photocatalyst and cannot withstand the use of a building exterior. As a conventional technique, a one-coat coating film containing a photocatalytic material in a fluororesin has been realized (for example, see Patent Document 2). However, there is a problem that the ratio of exposure of the photocatalyst material to the outermost surface is small in one coat film, and in order to solve this, a device for increasing the exposure ratio of the outermost photocatalyst material has been devised (Patent Document 3). reference). However, even with such a device, the photocatalytic material integrated with the resin material has a problem that the photocatalytic performance such as hydrophilicity / organic matter decomposition activity cannot be sufficiently exhibited.

In order to solve the problem of the 1-coat photocatalyst coating film, a technique for forming a photocatalyst layer mainly composed of an inorganic component on an organic material is known. When a photocatalyst layer is formed on an organic material, there is a problem that the organic material is oxidatively decomposed or deteriorated due to photocatalytic activity. In order to solve this problem, by forming a 2-coat coating film in which an intermediate layer having high resistance to oxidative degradation such as a silicone-modified resin is formed between the photocatalyst layer and the organic material base material, A technique for protecting against deterioration due to action is known (see, for example, Patent Document 1 (International Publication No. 97/00134)).

An intermediate layer containing a fluororesin has conventionally been used in the two-coat coating film, and in Patent Document 4, polytetrafluoroethylene is used as an intermediate layer that is not easily affected by the photocatalyst. However, although polytetrafluoroethylene is not oxidatively decomposed, it has a problem that it cannot be put into practical use as a building exterior coating because it has low adhesion to the photocatalyst layer and is easily peeled off.

In Patent Document 5, in order to realize a laminate coating film of an intermediate layer containing a fluororesin and a hydrophilic layer, an acrylic resin is combined with the fluororesin of the intermediate layer, and the hydrophilic layer is made hydrophilic by using colloidal silica or the like. An antifouling coating is realized. However, there is a problem that it is difficult to maintain high antifouling property for a long time because the silica film having no photocatalytic activity is gradually contaminated. Moreover, when a photocatalyst coating film is used as a hydrophilic layer in order to eliminate this, the adhesiveness of an intermediate | middle layer and a photocatalyst layer falls by a photocatalytic reaction, and will peel. Therefore, in order to use it practically, only a photocatalytic coating film having low photocatalytic activity can be combined, and there is a problem that high antifouling properties cannot be exhibited.

International Publication No. 97/00134 Japanese Patent Laid-Open No. 2006-204981 Japanese Patent Laying-Open No. 2015-221567 JP 2000-006303 A JP 2017-052277 A

The present disclosure provides a laminate coating film that can maintain the adhesion between the photocatalyst layer and the intermediate layer for a long period of time.

The present disclosure is a laminate coating film including a base material, an intermediate layer formed on the base material, and a photocatalyst layer formed on the intermediate layer, and the intermediate layer segregates the inorganic polymer on the surface. It is a laminated body coating film characterized by including the particulate resin composite and the photocatalyst layer containing photocatalyst particles and inorganic oxide particles.

The resin composite preferably has a core-shell structure.

The resin composite preferably has a shell portion thickness of 5.0 nm or more.

The resin composite preferably contains a fluoropolymer, a (meth) acrylic polymer, and an inorganic polymer.

The inorganic polymer is preferably polysiloxane.

The fluoropolymer preferably includes a vinylidene fluoride unit and at least one fluoroolefin unit selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene.

The (meth) acrylic polymer preferably contains at least one acrylic monomer unit selected from the group consisting of acrylic acid, acrylic ester, methacrylic acid and methacrylic ester.

The (meth) acrylic polymer is preferably obtained by seed polymerization of a (meth) acrylic monomer in an aqueous dispersion containing a fluoropolymer.

The resin composite is preferably a polycondensation of silanol in the presence of a (meth) acrylic polymer obtained by seed polymerization.

The photocatalyst layer contains 1% by mass and less than 20% by mass of photocatalyst particles, more than 70% by mass and less than 99% by mass of inorganic oxide particles, and 0% by mass or more and less than 10% by mass of an inorganic binder. Is preferred.

The inorganic oxide particles preferably have an average particle size of 50 nm or less.

The laminate coating film of the present disclosure is preferably used as an exterior material.

The laminated body coating film of this indication can maintain the adhesiveness of a photocatalyst layer and an intermediate | middle layer for a long period because an intermediate | middle layer contains a specific resin composite.

2 is a cross-sectional secondary electron image of an intermediate layer of a laminate coating film obtained in Comparative Example 1. 2 is a cross-sectional secondary electron image of an intermediate layer of a laminate coating film obtained in Example 1. 3 is a cross-sectional backscattered electron image of an intermediate layer of a laminate coating film obtained in Comparative Example 1. 2 is a cross-sectional backscattered electron image of an intermediate layer of a laminate coating film obtained in Example 1. FIG. It is an observation result with the laser microscope of the coating-film surface after the weather resistance test of the laminated body coating film obtained in the comparative example 2. FIG. It is an observation result with the laser microscope of the coating-film surface after the weather resistance test of the laminated body coating film obtained in Example 8. FIG.

The laminate coating film of the present disclosure is a laminate coating film including a base material, an intermediate layer formed on the base material, and a photocatalyst layer formed on the intermediate layer, and the intermediate layer is formed on the surface. It includes a particulate resin composite in which an inorganic polymer is segregated, and the photocatalyst layer includes photocatalyst particles and inorganic oxide particles.

A two-coat film in which a fluororesin is used for the intermediate layer and a photocatalyst layer is laminated has been studied. However, in the film described in Patent Documents 1 to 5, strong photocatalytic activity that exhibits organic matter decomposability and antifouling properties In addition, it has been difficult to achieve both weather resistance that can withstand long-term use over several decades.
The laminate coating film of the present disclosure has a strong photocatalytic activity because the intermediate layer contains a particulate resin composite having an inorganic polymer segregated on the surface, thereby maintaining the adhesion between the intermediate layer and the photocatalyst layer for a long period of time. And an excellent laminate coating film that achieves both long-term weather resistance and can be suitably applied to applications requiring strong photocatalytic activity and long-term weather resistance.

(Base material)
The base material used in the present disclosure may be various materials regardless of whether it is an inorganic material or an organic material as long as it can form an intermediate layer thereon, and the shape thereof is not limited. Preferred examples of the substrate from the viewpoint of materials include metals, ceramics, glass, plastics, rubber, stones, cement, concrete, fibers, fabrics, wood, paper, combinations thereof, laminates thereof, Examples thereof include those having at least one layer of coating on the surface. Preferred examples of the base material from the viewpoint of use include building materials, building exteriors, window frames, window glass, structural members, exteriors and coatings of vehicles, exteriors of machinery and articles, dust covers and coatings, traffic signs, various displays Equipment, advertising towers, road noise barriers, railway noise barriers, bridges, guardrail exteriors and paintings, tunnel interiors and paintings, insulators, solar cell covers, solar water heater heat collection covers, plastic houses, vehicle lighting covers General exterior materials such as outdoor lighting fixtures, stands, and films, sheets, seals and the like for attaching to the surface of the article.

According to a preferred embodiment of the present disclosure, a substrate having at least a surface formed of an organic material can be used as the substrate, and the entire substrate is configured of an organic material or an inorganic material. Any of those in which the surface of the substrate is coated with an organic material (for example, a decorative board) is included.

(Middle layer)
The intermediate layer in the present disclosure includes a particulate resin composite in which an inorganic polymer is segregated on the surface. Due to these characteristics, the intermediate layer in the present disclosure is excellent in long-term adhesion with the photocatalyst layer. The resin composite preferably has an agglomerated structure from the viewpoint of better long-term adhesion between the intermediate layer and the photocatalyst layer.

The resin composite preferably has a core-shell structure of a resin core and an inorganic polymer shell. The resin composite preferably has a shell part thickness of 5.0 nm or more, more preferably 10 nm or more, further preferably 15 nm or more, and still more preferably 20 nm or more. Although the upper limit of the thickness of a shell part is not specifically limited, 50 nm may be sufficient and 40 nm may be sufficient. The thickness of the shell portion was determined by observing the cross-section of the intermediate layer cut out from the laminate coating film by ion milling method with a backscattered electron image of a field emission electron microscope (acceleration voltage: 3.0 kV), and a field of view of 60,000 times It is calculated as a number average value obtained by measuring the thicknesses of the shell portions of any 10 resin composites that fall within.

The resin composite preferably contains a fluoropolymer, a (meth) acrylic polymer, and an inorganic polymer. With these characteristics, an intermediate layer having excellent adhesion to the substrate and adhesion to the photocatalyst layer can be formed. In addition, the properties of fluoropolymers, (meth) acrylic polymers, and inorganic polymers are fully exhibited, and it is possible to form a coating film that is excellent not only in adhesion to the substrate but also in water resistance and solvent resistance. it can.

The fluoropolymer preferably contains a fluoroolefin unit. Examples of the fluoroolefin include tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoro (alkyl vinyl ether) (PAVE),

Perfluoroolefins such as: chlorotrifluoroethylene (CTFE), vinyl fluoride (VF), vinylidene fluoride (VdF), trifluoroethylene, trifluoropropylene, hexafluoroisobutene, 2,3,3,3-tetrafluoro Non-perfluoroolefins such as propene, 1,3,3,3-tetrafluoropropene and 1,1,3,3,3-pentafluoropropene are exemplified. Examples of perfluoro (alkyl vinyl ether) include perfluoro (methyl vinyl ether) (PMVE), perfluoro (ethyl vinyl ether) (PEVE), perfluoro (propyl vinyl ether) (PPVE), and the like.

Moreover, a functional group-containing fluoroolefin can also be used as the fluoroolefin.
Examples of the functional group-containing fluoroolefin include a general formula:
_{^{CX 3 2 = CX 4 - (}} Rf) m -Y 1
^(Wherein, Y 1 is _{^{-OH, -COOM 2, -SO 2 F}} , -SO 3 M 2 (M 2 represents a hydrogen atom, NH ₄ group or an alkali metal), carboxylate, carboxylic ester group, an epoxy group, or A cyano group; X ³ and X ⁴ are the same or different and both are hydrogen atoms or fluorine atoms; Rf is a divalent fluorine-containing alkylene group or fluorine-containing oxyalkylene group having 1 to 40 carbon atoms, or 2 to 40 carbon atoms And a divalent fluorine-containing alkylene group or fluorine-containing oxyalkylene group containing an ether bond; m is 0 or 1).

Among these, the fluoroolefin is preferably at least one selected from the group consisting of vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene.

The fluoroolefin is more preferably vinylidene fluoride and at least one selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene.

The fluoropolymer preferably includes a vinylidene fluoride unit and at least one fluoroolefin unit selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene.

In addition to the fluoroolefin unit, the fluoropolymer may contain a non-fluorine monomer unit copolymerizable with the fluoroolefin. Examples of non-fluorine monomers copolymerizable with the fluoroolefin include olefins such as ethylene, propylene, and isobutylene, vinyl ether monomers, allyl ether monomers, vinyl ester monomers, acrylics, and the like. And monomers based on methacrylic monomers and methacrylic monomers.

The fluoropolymer preferably contains a vinylidene fluoride unit as the fluoroolefin unit because it can form a coating film that is more excellent in solvent resistance, antifouling property, and adhesion to the substrate. From the viewpoint of compatibility with the (meth) acrylic polymer, it is preferable that the vinylidene fluoride unit in the fluoropolymer is 50 mol% or more with respect to all the polymerized units constituting the fluoropolymer, and 70 mol% or more. More preferably, it is preferably 95 mol% or less.

As the fluoropolymer, a group consisting of VdF / TFE / CTFE copolymer, VdF / TFE copolymer, VdF / TFE / HFP copolymer, VdF / CTFE copolymer, VdF / HFP copolymer, and PVdF It is preferably at least one selected from the group consisting of VdF / TFE / CTFE = 40 to 99/1 to 50/0 to 30 (mol%), VdF / TFE = 50 to 99/1 to 50 (mol%). VdF / TFE / HFP = 45 to 99/0 to 35/5 to 50 (mol%), VdF / CTFE = 40 to 99/1 to 30 (mol%), and VdF / HFP = 50 to 99/1 More preferably, it is at least one selected from the group consisting of ˜50 (mol%).
As the fluoropolymer, a VdF / TFE / CTFE copolymer is particularly preferable. VdF / TFE / CTFE copolymer is more preferably VdF / TFE / CTFE = 40 to 99/1 to 50/1 to 30 (mol%), and 50 to 90/5 to 40/1 to 25 (mol%). Is more preferable, and 60-90 / 5-30 / 5-20 (mol%) is still more preferable.

The (meth) acrylic polymer contains (meth) acrylic monomer units. Examples of the (meth) acrylic monomer include (meth) acrylic acid and (meth) acrylic acid ester. In this specification, “(meth) acrylic acid” means acrylic acid or methacrylic acid.
The (meth) acrylic polymer preferably contains at least one acrylic monomer unit selected from the group consisting of acrylic acid, acrylic ester, methacrylic acid and methacrylic ester.

The (meth) acrylic polymer preferably contains an acrylate unit or a methacrylic ester unit because it can form a coating film that is more excellent in solvent resistance, antifouling property, and adhesion to the substrate. More preferably, it contains an acrylate unit and a methacrylate unit.

As the (meth) acrylic acid ester, an alkyl alkyl ester having 1 to 10 carbon atoms in the alkyl group or a methacrylic acid alkyl ester having 1 to 10 carbon atoms in the alkyl group is preferable. Examples of the (meth) acrylic acid ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, methyl methacrylate, n-propyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, Examples include (meth) acrylic acid alkyl esters such as 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate.

The (meth) acrylic acid ester is at least one selected from the group consisting of methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate. Species are preferred.
Also, 2-hydroxyethyl methacrylate (2-HEMA), 2-hydroxyethyl acrylate (2-HEA), 3-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate, 4- Examples include hydroxyl-containing (meth) acrylic acid esters such as hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 6-hydroxyhexyl acrylate and 6-hydroxyhexyl methacrylate. At least one selected from the group consisting of 2-HEMA and 2-HEA is preferred. It is preferable that the said hydroxyl-containing (meth) acrylic acid ester unit is 0-20 mass% with respect to all the monomer units which comprise a (meth) acrylic polymer.
In the present specification, the hydroxyl group is a group represented by —OH, but does not include a hydroxyl group constituting a part of a carboxy group (—COOH).

The (meth) acrylic polymer preferably contains a hydrolyzable silyl group-containing unsaturated monomer unit. Thereby, the solvent resistance of the coating film obtained from an aqueous dispersion, antifouling property, and adhesiveness with a base material can be made still more excellent.

The hydrolyzable silyl group has a general formula:
A group represented by —SiX ¹ _n X ² _3-n (X ¹ is a C _1-10 alkoxy group, X ² is H or a C _1-10 alkyl group, and n is an integer of 1 to 3). Preferably there is.
From the viewpoint of improving the solvent resistance of the coating film, the reactivity of the hydrolyzable silyl group is better, and the hydrolyzable silyl group is -Si (OCH ₃ ) _n X ² _3-n or -Si (OC ₂ H ₅ ) _n X ² _3-n is more preferable, and —Si (OCH ₃ ) ₃ or —Si (OC ₂ H ₅ ) ₃ is still more preferable.

As the hydrolyzable silyl group-containing unsaturated monomer,
CH ₂ = CHSi (OCH ₃ ) ₃ ,
CH ₂ = CHSi (CH ₃ ) (OCH ₃ ) ₂ ,
_{CH 2 = C (CH 3)} Si (OCH 3) 3,
_{CH 2 = C (CH 3)} Si (CH 3) (OCH 3) 2,
_{CH 2 = CHSi (OC 2 H} 5) 3,
_{CH 2 = CHSi (OC 3 H} 7) 3,
_{CH 2 = CHSi (OC 4 H} 9) 3,
_{CH 2 = CHSi (OC 6 H} 13) 3,
_{CH 2 = CHSi (OC 8 H} 17) 3,
_{CH 2 = CHSi (OC 10 H} 21) 3,
_{CH 2 = CHSi (OC 12 H} 25) 3,
_{CH 2 = CHCOO (CH 2)} 3 Si (OCH 3) 3,
_{CH 2 = CHCOO (CH 2)} 3 Si (CH 3) (OCH 3) 2,
_{CH 2 = CHCOO (CH 2)} 3 Si (OC 2 H 5) 3,
_{CH 2 = CHCOO (CH 2)} 3 Si (CH 3) (OC 2 H 5) 2,
_{CH 2 = C (CH 3)} COO (CH 2) 3 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 (OC 2 H 5) 3,
_{CH 2 = C (CH 3)} COO (CH 2) 3 Si (CH 3) (OC 2 H 5) 2,
_{CH 2 = C (CH 3)} COO (CH 2) 2 O (CH 2) 3 Si (OCH 3) 3,
_{CH 2 = C (CH 3)} COO (CH 2) 2 (CH 2) 3 Si (CH 3) (OCH 3) 2,
_{CH 2 = C (CH 3)} COO (CH 2) 11 Si (OCH 3) 3,
_{CH 2 = C (CH 3)} COO (CH 2) 11 Si (CH 3) (OCH 3) 2,
_{CH 2 = CHCH 2 OCO (o} -C 6 H 4) COO (CH 2) 3 Si (OCH 3) 3,
_{CH 2 = CHCH 2 OCO (o} -C 6 H 4) COO (CH 2) 3 Si (CH 3) (OCH 3) 2,
_{CH 2 = CH (CH 2)} 4 Si (OCH 3) 3,
_{CH 2 = CH (CH 2)} 8 Si (OCH 3) 3,
_{CH 2 = CHO (CH 2)} 3 Si (OCH 3) 3,
_{CH 2 = CHCH 2 O (CH} 2) 3 Si (OCH 3) 3,
_{CH 2 = CHCH 2 OCO (CH} 2) 10 Si (OCH 3) 3
Etc.

The hydrolyzable silyl group-containing unsaturated monomer unit can form a coating film that is more excellent in solvent resistance, antifouling property, and adhesion to a base material. It is preferable that it is 0.01 mass% or more with respect to all the monomer units which comprise an acrylic polymer, and it is more preferable that it is 0.1 mass% or more. 5 mass% or less is preferable and 3 mass% or less is more preferable. If the amount of the hydrolyzable silyl group-containing unsaturated monomer unit is too large, the transparency of the coating film may be impaired. If the amount is too small, the solvent resistance and substrate adhesion of the coating film may be impaired.
The (meth) acrylic polymer may contain an unsaturated carboxylic acid unit such as a carboxy group from the viewpoint of long-term stability of the aqueous dispersion.
As the unsaturated carboxylic acid, acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, cinnamic acid, 3-allyloxypropionic acid, 3- (2-allyloxyethoxycarbonyl) propionic acid, itaconic acid, itaconic acid monoester Maleic acid, maleic acid monoester, maleic anhydride, fumaric acid, fumaric acid monoester, vinyl phthalate, vinyl pyromellitic acid, undecylenic acid and the like. Among them, acrylic acid, methacrylic acid, vinyl acetic acid, crotonic acid, itaconic acid, maleic acid, maleic acid monoester, fumaric acid, fumaric acid monoester, 3-allyloxypropion are easy to control the introduction of carboxyl group. At least one selected from the group consisting of an acid and undecylenic acid is preferred.
More preferably, at least one selected from the group consisting of acrylic acid and methacrylic acid is preferable.

The resin composite includes an inorganic polymer. The inorganic polymer is a polymer whose skeleton is formed of an oxide of an inorganic element. Examples of such inorganic elements include silicon (Si), titanium (Ti), aluminum (Al), and zirconium (Zr). Si is preferable as the inorganic element. As the inorganic polymer, polysiloxane is more preferable.

As said polysiloxane, the polycondensate of the hydrolyzate of the organosilane represented by the following general formula (3-1) is mentioned, for example.

(In the formula, R ¹ represents a monovalent organic group having 1 to 8 carbon atoms, and two R ^{1 s} may be the same or different from each other, and R ² is a straight chain having 1 to 5 carbon atoms or It shows a branched alkyl group or an acyl group having 1 to 6 carbon atoms, R ² present two may be the same or different, n represents consists an integer of 0 to 2.).

In the general formula (3-1), examples of the monovalent organic group having 1 to 8 carbon atoms of R ¹ include phenyl group; methyl group, ethyl group, n-propyl group, i-propyl group, and n-butyl. Group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, cyclopentyl group, cyclohexyl group, etc. Or cyclic alkyl group; acyl group such as acetyl group, propionyl group, butyryl group, valeryl group, benzoyl group, trioyl group, caproyl group; alkenyl group such as vinyl group and allyl group, and substituted derivatives of these groups Epoxy group, glycidyl group, (meth) acryloyloxy group, ureido group, amide group, fluoroacetamide group, isocyanate group and the like.

Examples of the substituent in the substituted derivative of R ¹ 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, and (meth) acryloyloxy. Group, ureido group, ammonium base and the like. However, the total carbon number of R ¹ composed of these substituted derivatives is 8 or less including the carbon atom in the substituent.

Examples of the linear or branched 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, and a sec-butyl group. ,
A t-butyl group, n-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 include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane; methyltrimethoxysilane, methyl Triethoxysilane, 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-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxy Silane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyl Trialkoxysilanes such as triethoxysilane, 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, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyl Diethoxysilane, diphenyl In addition to dialkoxysilanes such as methoxysilane, diphenyldiethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropyldiethoxymethylsilane, methyltriacetyloxysilane, dimethyldiacetyloxysilane, etc. be able to.

Among these organosilanes, tetraalkoxysilanes, trialkoxysilanes, and dialkoxysilanes are preferable. Tetraalkoxysilanes are preferably tetraethoxysilane, trialkoxysilanes are preferably methyltrimethoxysilane and methyltriethoxysilane, and dialkoxysilanes are preferably dimethyldimethoxysilane and dimethyldiethoxysilane. preferable.
The above organosilanes can be used alone or in admixture of two or more.

The hydrolyzate of the above organosilane is one in which the Si-OR ² group in the organosilane is hydrolyzed to form a silanol (Si-OH) group. Here, the OR ² group of the organosilane has Not all have to be hydrolyzed.
The polycondensate of the hydrolyzate of organosilane is a product in which silanol groups in the hydrolyzate are condensed to form a siloxane (Si-O-Si) bond. These groups are all condensed. It is not necessary to have a part of the group condensed.

The organosilane polycondensate may be only trialkoxysilanes, or may be obtained from a combination of trialkoxysilanes 40 to 99 mol% and tetraalkoxysilanes 60 to 1 mol%. Also good. The weather resistance can be improved by using trialkoxysilane and tetraalkoxysilane at this ratio. Furthermore, you may contain dialkoxysilane in the ratio of 0-55 mol%.

The resin composite preferably has a mass ratio (A / B / C) of fluoropolymer, (meth) acrylic polymer, and inorganic polymer of 80 to 20/80 to 20/20 to 0.1. It is more preferable that it is -30 / 70-30 / 15-1, and it is still more preferable that it is 65-35 / 65-35 / 10-2. When the mass ratio (A / B / C) is within the above range, it is possible to form a coating film that is more excellent in solvent resistance, antifouling property, and adhesion to the substrate. If the amount of the inorganic polymer is too much, the coating film may be fragile. If the amount is too small, the adhesion with the photocatalyst layer may be deteriorated.

The resin composite is, for example, a seed polymerization step in which a (meth) acrylic monomer is seed-polymerized in an aqueous dispersion containing a fluoropolymer, and silanol condensation polymerization in the presence of the acrylic polymer obtained by seed polymerization. It can be suitably manufactured by a method including a condensation polymerization step.

By the seed polymerization step, a dispersion containing particles containing a fluoropolymer and a (meth) acrylic polymer can be obtained.
The seed polymerization step can be performed by adding a (meth) acryl monomer and, if necessary, another monomer to an aqueous dispersion containing a fluoropolymer. For example, the method of dripping the emulsion containing a (meth) acryl monomer, surfactant, and water to the aqueous dispersion containing a fluoropolymer is mentioned.
The aqueous dispersion contains water. In addition to water, you may contain organic solvents, such as alcohol, glycol ether, and ester.

The seed polymerization is preferably carried out in the presence of a non-reactive anionic surfactant, a reactive anionic surfactant, a non-reactive nonionic surfactant, a reactive nonionic surfactant, or the like.
The seed polymerization is preferably performed in the presence of at least one selected from the group consisting of a reactive anionic surfactant and a reactive nonionic surfactant, and is performed in the presence of a reactive anionic surfactant. It is more preferable. Examples of the reactive anionic surfactant include allylic or acrylic reactive groups, and allylic is preferable.

In the seed polymerization, the amount of the reactive anionic surfactant added is preferably 0.1 to 50 parts by weight, more preferably 0.5 parts by weight or more, with respect to 100 parts by weight of the seed particles. Is more preferable, 20 mass parts or less are more preferable, and 10 mass parts or less are still more preferable.

The polycondensation step can be performed by adding organosilane to an aqueous dispersion containing a fluoropolymer and an acrylic polymer obtained by seed polymerization.
The organosilane is hydrolyzed in the aqueous dispersion to form a silanol compound, and the silanol compound is polycondensed.

In the condensation polymerization step, it is preferable to add 0.5 to 20% by mass of organosilane with respect to 100% by mass in total of the fluoropolymer and the acrylic polymer. More preferably, the added amount is 2.5 to 10% by mass.

The production method may include a step of obtaining an aqueous dispersion containing a fluoropolymer by subjecting the fluoroolefin to aqueous dispersion polymerization. That is, the production method of the present disclosure includes a step of obtaining an aqueous dispersion containing a fluoropolymer by aqueous dispersion polymerization of a fluoroolefin, and seed polymerization in which a (meth) acryl monomer is seed-polymerized in the aqueous dispersion containing the fluoropolymer. It is also preferable to include a step and a polycondensation step of polycondensing silanol in the presence of a (meth) acrylic polymer obtained by seed polymerization.

In the aqueous dispersion polymerization, the aqueous dispersion contains water. In addition to water, you may contain organic solvents, such as alcohol, glycol ether, and ester.

The aqueous dispersion polymerization can be carried out in the presence of a non-reactive anionic surfactant, a reactive anionic surfactant, a non-reactive nonionic surfactant, a reactive nonionic surfactant, or the like, if desired. As these surfactants, those exemplified in the seed polymerization step can be preferably used.

The aqueous dispersion may be added with a pH adjuster, a film-forming aid, an antifoaming agent, etc., if necessary.
Examples of the pH adjuster include aqueous ammonia and amines. As the film-forming aid, various commercially available film-forming aids can be used. Specifically, dipropylene glycol-n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol diethyl ether, ethylene glycol mono 2-ethylhexyl ether, diethyl adipate, butyl carbitol acetate, 2 , 2,4-trimethylpentane-1,3-diol monoisobutyrate and other polyhydric alcohol alkyl ethers, organic acid esters, and the like, but are not limited thereto. Examples of the antifoaming agent include silicone-based antifoaming agents, surfactants, polyethers, organic antifoaming agents such as higher alcohols, and the like.

The intermediate layer preferably has a thickness of 1 to 200 μm, more preferably 1 to 100 μm, still more preferably 5 to 50 μm, and further preferably 5 to 30 μm. Is more preferable.

(Photocatalyst layer)
The photocatalyst layer in the present disclosure includes photocatalyst particles and inorganic oxide particles.

The photocatalyst particles are not particularly limited as long as they have particles having photocatalytic activity, and all kinds of photocatalyst particles can be used. Examples of the photocatalyst particles include metal oxide particles such as titanium oxide (TiO ₂ ), ZnO, SnO ₂ , SrTiO ₃ , WO ₃ , Bi ₂ O ₃ , Fe ₂ O ₃ , and preferably titanium oxide. Particles, more preferably anatase type titanium oxide particles. Titanium oxide is harmless, chemically stable, and available at low cost. Titanium oxide has a high band gap energy, and therefore requires ultraviolet light for photoexcitation and does not absorb visible light in the process of photoexcitation, so that no color formation due to a complementary color component occurs. Titanium oxide is available in various forms such as powder, sol, and solution, but any form can be used as long as it exhibits photocatalytic activity. According to a preferred embodiment of the present disclosure, the photocatalyst particles preferably have an average particle size of 10 nm to 100 nm, more preferably 10 nm to 60 nm. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. As the shape of the particle, a true sphere is the best, but it may be approximately circular or elliptical, and the length of the particle in this case is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited. In addition, a photocatalyst layer having particularly good transparency can be obtained by using a commercially available photocatalyst in sol form and setting the particle diameter to 30 nm or less, preferably 20 nm or less.

The content of the photocatalyst particles is preferably more than 1% by mass and less than 20% by mass, more preferably 5% by mass to 15% by mass, and still more preferably 5% by mass to 10% by mass. By reducing the blending ratio of the photocatalyst particles in this way, the direct contact of the photocatalyst particles with the base material can be reduced as much as possible to prevent erosion of the base material (especially organic material) and the weather resistance is also improved. It is thought to improve. Nevertheless, functions due to photocatalytic activity such as decomposability of harmful gas and ultraviolet absorption can be sufficiently exhibited.

According to a preferred embodiment of the present disclosure, the material is selected from the group consisting of titania and vanadium, iron, cobalt, nickel, palladium, zinc, ruthenium, rhodium, copper, silver, platinum and gold in order to develop higher photocatalytic ability. At least one metal and / or a metal compound comprising the metal can be added to the photocatalyst layer and the photocatalyst coating solution. This addition is performed by any of the method of adding a solution in which the photocatalyst and the metal or metal compound coexist as it is, and the method of supporting the metal or metal compound on the photocatalyst using the photocatalytic oxidation-reduction action. Can do.

The inorganic oxide particles are not particularly limited as long as they are inorganic oxide particles capable of forming a layer together with the photocatalyst particles, and any kind of inorganic oxide particles can be used. Examples of such inorganic oxide particles include single oxide particles such as silica, alumina, zirconia, ceria, yttria, boronia, magnesia, calcia, ferrite, amorphous titania, hafnia; and barium titanate, silica The particle | grains of complex oxides, such as calcium acid, are mentioned, More preferably, it is a silica particle. These inorganic oxide particles are preferably in the form of an aqueous colloid using water as a dispersion medium; or an organosol dispersed in a hydrophilic solvent such as ethyl alcohol, isopropyl alcohol, or ethylene glycol, and particularly preferably. Colloidal silica.

According to a preferred aspect of the present disclosure, the inorganic oxide particles preferably have an average particle size of 50 nm or less. By being in this range, sufficient adhesion with the intermediate layer can be ensured. More preferably, it is 5-25 nm, More preferably, it is 10-25 nm. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. As the shape of the particle, a true sphere is the best, but it may be approximately circular or elliptical, and the length of the particle in this case is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired film properties (ultraviolet absorption, transparency, film strength, etc.) are efficiently exhibited. In particular, a photocatalyst layer that is transparent and has good adhesion can be obtained.

The content of the inorganic oxide particles is preferably more than 70% by mass and less than 99% by mass, more preferably more than 75% by mass and 95% by mass or less, still more preferably more than 80% by mass and 95% by mass or less. Still more preferably, it is 85 mass% or more and 95 mass% or less, Most preferably, it is 90 mass% or more and 95 mass% or less.

The photocatalyst layer in the present disclosure may contain an inorganic binder in addition to the photocatalyst particles and the inorganic oxide particles. As an inorganic binder, a hydrophilic inorganic amorphous substance etc. can be mentioned, for example. Examples thereof include those containing one or more selected from the group consisting of alkali metal silicates, alkali borosilicates, alkali zirconates, and metal phosphates such as alkali phosphates. These substances have a function of adhering and fixing the photocatalyst particles and the inorganic oxide particles, and as a result, have an effect of improving the adhesion between the intermediate layer and the photocatalyst layer. Furthermore, a chemically adsorbed water layer can be easily formed due to the presence of water, and can exhibit hydrophilicity over a long period of time. Among these, alkali silicate is preferable, and more preferable examples include at least one of sodium silicate, potassium silicate, lithium silicate, and ammonium silicate. In general, the adhesiveness is strong in the order of sodium silicate and potassium silicate, and the water resistance is considered to be strong in the order of ammonium silicate and lithium silicate, but it is more preferable to include lithium silicate in view of the film property, film hardness, water resistance and the like.

The photocatalyst layer in the present disclosure comprises more than 1% by mass and less than 20% by mass photocatalyst particles, more than 70% by mass and less than 99% by mass inorganic oxide particles, and 0% by mass or more and less than 10% by mass inorganic binder. It is preferable to contain, and it is more preferable to contain 5-15 mass% photocatalyst particle, 75-95 mass% inorganic oxide particle, and 0-5 mass% inorganic binder.

The photocatalyst layer in the present disclosure comprises a photocatalyst layer, an inorganic oxide particle, an inorganic binder as an optional component, and a surfactant as an optional component dispersed or dissolved in a solvent on a substrate. It can be formed by coating.

The photocatalyst layer coating composition may contain a surfactant as an optional component. The surfactant may be contained in the photocatalyst layer at 0 to 10% by mass, preferably 0 to 8% by mass, more preferably 0 to 6% by mass. is there. One of the effects of the surfactant is leveling property to the intermediate layer, and the amount of the surfactant may be appropriately determined depending on the combination of the coating composition for the photocatalyst layer and the intermediate layer. It may be 1% by mass. This surfactant is an effective component for improving the wettability of the coating composition for the photocatalyst layer, but the photocatalyst layer formed after coating no longer contributes to the effect of the laminate coating film of the present disclosure. Corresponds to inevitable impurities. Therefore, depending on the wettability required for the coating composition for the photocatalyst layer, it may be used within the above content range, and if the wettability is not a problem, the surfactant is substantially or not included at all. Good. The surfactant to be used can be appropriately selected in consideration of the dispersion stability of the photocatalyst and inorganic oxide particles, and wettability when applied on the intermediate layer, but a nonionic surfactant is preferable, More preferably, an ether type nonionic surfactant, an ester type nonionic surfactant, a polyalkylene glycol nonionic surfactant, a fluorine-based nonionic surfactant, or a silicone-based nonionic surfactant is used. Can be mentioned.

According to a preferred embodiment of the present disclosure, the photocatalyst layer preferably has a film thickness of 0.3 μm or more and 3.0 μm or less, more preferably 0.5 μm or more and 1.5 μm or less. Within such a range, the ultraviolet rays that reach the interface between the photocatalyst layer and the intermediate layer are sufficiently attenuated, thereby improving the weather resistance. Moreover, since the photocatalyst particles having a lower content ratio than the inorganic oxide particles can be increased in the film thickness direction, harmful gas decomposability is also improved. Furthermore, excellent characteristics can be obtained in terms of ultraviolet absorption, transparency, and film strength. Moreover, since light scattering by the photocatalyst particles and the inorganic oxide particles is small, the photocatalyst layer is less clouded and excellent in appearance.

(Production method)
The laminate coating film of the present disclosure is obtained by applying a coating composition for an intermediate layer containing a particulate resin composite on a substrate, and then applying a photocatalyst to the surface opposite to the substrate of the obtained intermediate layer application body. It can manufacture easily by apply | coating the coating composition for photocatalyst layers containing particle | grains and an inorganic oxide particle. The coating composition for intermediate | middle layers may contain the hardening | curing agent, the pigment, the filler, the thickener, etc. as needed. The coating method of the coating composition for the intermediate layer and the coating composition for the photocatalyst layer is generally widely used such as brush coating, roller, spray, roll coater, flow coater, dip coating, flow coating, screen printing, electrodeposition, vapor deposition, etc. The methods that are available are available. After application of the intermediate layer coating composition and after application of the photocatalyst layer coating composition, it may be dried at room temperature, or may be heat-dried as necessary.

Although the laminated body coating film of this indication is concretely demonstrated based on the following examples, the laminated body coating film of this indication is not limited to these examples.
In addition, the raw material used for preparation of the coating composition for intermediate | middle layers and the coating composition for photocatalyst layers in the following examples is as follows.
Curing agent: carbodiimide-based curing agent photocatalyst particles: titania aqueous dispersion (average particle size: 60 nm, basic) The average particle size was calculated from the scattering intensity measured using the dynamic light scattering method, using cumulant analysis.
Inorganic oxide particles: water-dispersed colloidal silica (average particle size: 25 nm, basic) The average particle size is the number of particles measured by measuring the length of 100 arbitrary particles entering a 200,000-fold field of view with a scanning electron microscope Calculated as an average value.
Inorganic binder: Lithium silicate Surfactant: Polyether-modified silicone surfactant Silica sand: Silica sand No. 8 thickener: Alkali swelling thickener

Preparation Example 1
VdF / TFE / CTFE polymer (VdF / TFE / CTFE = 72/15/13 (mole) was added to a 2 liter glass four-necked separable flask equipped with a stirrer, reflux tube, thermometer and dropping funnel. %)) Aqueous dispersion of particles, methyl methacrylate (MMA) 126 parts by mass, n-butyl acrylate (BA) 167 parts by mass, n-butyl methacrylate (BMA) 0.03 parts by mass, cyclohexyl methacrylate (CHMA) ) 0.03 parts by mass, 2-hydroxyethyl methacrylate (2-HEMA) 0.03 parts by mass, methacrylic acid 5.5 parts by mass, γ-methacryloxypropyltrimethoxysilane 1.8 parts by mass, water 100 g, polyoxy Ethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium salt 12.5 Stirring Enter the amount unit while heated. When the bath temperature reached 80 ° C., polymerization was started by adding dropwise the polymerization initiator over 2 hours. After stirring at 80 ° C. for 2 hours from the end of dropping, the reaction was terminated by cooling to room temperature. Neutralization was performed with a pH adjuster to adjust the pH to 8.0, whereby an aqueous dispersion of the resin composite 1 was obtained. The mass ratio (A / B) of the fluoropolymer (A) and the (meth) acrylic polymer (B) was 50/50.

Preparation Example 2
VdF / TFE / CTFE polymer (VdF / TFE / CTFE = 72/15/13 (mole) was added to a 2 liter glass four-necked separable flask equipped with a stirrer, reflux tube, thermometer and dropping funnel. %)) Aqueous dispersion of particles, methyl methacrylate (MMA) 112 parts by mass, n-butyl acrylate (BA) 115 parts by mass, n-butyl methacrylate (BMA) 0.03 parts by mass, cyclohexyl methacrylate (CHMA) ) 0.03 parts by mass, 0.03 parts by mass of 2-hydroxyethyl methacrylate (2-HEMA), 5.3 parts by mass of methacrylic acid, 1.8 parts by mass of γ-methacryloxypropyltrimethoxysilane, 100 g of water, polyoxy Ethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium salt 12.5 Stirring Enter the amount unit while heated. When the bath temperature reached 80 ° C., polymerization was started by adding dropwise the polymerization initiator over 2 hours. It stirred at 80 degreeC for 2 hours after completion | finish of dripping.
Next, 62 parts by mass of trimethoxymethylsilane and 0.6 parts by mass of tetraethoxysilane were added dropwise at 80 ° C. over 0.5 hours, and then stirred for 1 hour. Then, it cooled to room temperature, the reaction was complete | finished, neutralized with the pH adjuster, pH 8.0 was obtained, and the aqueous dispersion of the fluoropolymer, the (meth) acrylic polymer, and the resin composite 2 of the siloxane polymer was obtained. The mass ratio (A / B / C) of the fluoropolymer (A), the (meth) acrylic polymer (B), and the siloxane polymer (C) was 50/45/5.

Preparation Example 3
Ion exchange water as a dispersion medium, an aqueous dispersion of the resin composite 1, and a curing agent were mixed at a blending ratio shown in Table 1 to prepare an intermediate layer coating composition B1. The solid content concentration of the fluororesin was adjusted to 20.0% by mass. In addition, the density | concentration of the hardening | curing agent in Table 1 means the solid content concentration of the hardening | curing agent with respect to 100 mass% of resin solid content.

Preparation Example 4
An intermediate layer coating composition B2 was prepared in the same manner as in Preparation Example 3, except that the resin composite 1 was changed to the resin composite 2.

Preparation Example 5
A titania aqueous dispersion as photocatalyst particles, water-dispersed colloidal silica as inorganic oxide particles, water as a dispersion medium, and a polyether-modified silicone surfactant are mixed at a blending ratio shown in Table 2. The photocatalyst layer coating composition T1 was obtained. In Table 2, the concentration of the photocatalyst particles and inorganic oxide particles means the concentration in the solid content of the photocatalyst coating film, while the concentration of the surfactant is the interface with respect to 100% by mass of the coating composition for photocatalyst layer. It means the concentration of the active agent. The total solid content concentration of the photocatalyst particles and the inorganic oxide particles in the coating composition for the photocatalyst layer was 5.5% by mass. Here, solid content concentration means the mass% when the coating composition for photocatalyst layers is dried at 105-110 degreeC, and becomes a constant weight.

Example 1 and Comparative Example 1
An epoxy sealer was applied to an aluminum plate and dried at room temperature to obtain a sealer coating. Further, an acrylic enamel was applied to the sealer coated body and sufficiently dried to obtain a base material.
The obtained substrate was heated to a plate temperature of 60 ° C., and the intermediate layer coating composition B1 or B2 was applied to the surface with an air spray at a coating amount of 150 ± 50 g / m ² and dried at 80 ° C. for 5 minutes. An intermediate layer was obtained.
Heating the intermediate layer-coated body in a plate temperature of 60 ° C., a photocatalyst layer coating composition T1, was coated by air spraying at a coverage of 10 ± 2.5g / m ^2, a laminate having a natural dried photocatalyst layer A coating film was obtained.
A cross section of the obtained laminate coating film was cut out by an ion milling method, and a secondary electron image and a reflected electron image of the cross section of the intermediate layer were observed by the following method. The results are shown in FIGS. In the intermediate layer of the laminate coating film obtained in Example 1, a resin composite having a core-shell structure with a shell part thickness of 26 nm was confirmed. On the other hand, no resin composite having a core-shell structure could be confirmed in the intermediate layer of the laminate coating film obtained in Comparative Example 1.
About the obtained laminated body coating film, the adhesiveness of an intermediate | middle layer and a photocatalyst layer was evaluated with the following method. The results are shown in Table 3.

(Observation method of secondary electron image and backscattered electron image)
Equipment used: FE-SEM (electrolytic emission scanning electron microscope)
Observation conditions: acceleration voltage 3.0 kV
Magnification 60,000 times

(Thickness of shell part of resin composite)
The thickness of the shell part is observed from the backscattered electron image of the cross section of the intermediate layer cut out from the laminate coating film by the ion milling method, and the thickness of the shell part of any 10 resin composites entering the field of view of 60,000 times It was calculated as the measured number average value.

(Adhesion between intermediate layer and photocatalyst layer)
The laminate coating film produced above was subjected to an exposure treatment for 600 hours in total using a QUV tester (manufactured by Q-LAB) under repeated conditions of illuminance of 0.63 W / m ² , irradiation for 4 hours, and condensation for 4 hours.
After that, using a rubbing tester IMC-150F-A type (manufactured by Imoto Seisakusho) with a rubbing head diameter of 20 mm, a paper wiper (trade name: JK Wiper, Nippon Paper Crecia Co., Ltd.) in which pure water was sufficiently soaked into the rubbing material. A rubbing test was performed at a load of 200 g and a speed of 45 reciprocations / minute.
When the surface was rubbed 1000 times, the surface contact angle with water was measured using a portable contact angle meter PCA-1 (manufactured by Kyowa Interface Science Co., Ltd.) and evaluated according to the following criteria.
◯: Water contact angle 50 ° or less Δ: Water contact angle 50 ° to 70 °
X: Water contact angle 70 ° or more

Examples 2-7
Coating for photocatalyst layer in the same manner as in Preparation Example 5, except that colloidal silica having an average particle size shown in Table 4 was used as the inorganic oxide particles, and lithium silicate was added as an inorganic binder in an amount shown in Table 4. Compositions T2 to T7 were prepared.
A laminate coating film was obtained in the same manner as in Example 1, except that the photocatalyst layer coating compositions T2 to T7 were used instead of the photocatalyst layer coating composition T1.
About the obtained laminated body coating film, tape adhesive force was evaluated with the following adhesive tape test methods. The results are shown in Table 4.

(Adhesive tape test method)
The following procedures 1-5 were evaluated with reference to JIS Z 0237: 2009.
1. 1. Specimen preparation: After preparation of the laminate coating film, left at 23 ± 1 ° C. and 50 ± 5% RH for 24 hours or longer. Test atmosphere: standard state as above (23 ± 1 ° C., 50 ± 5% RH)
3. 3. Crimping of tape: 2 reciprocations of 2 kg rubber roller at a speed of 10 ± 0.5 mm / sec. Peeling speed: The tape was turned at 180 ° and operated at 5.0 ± 0.2 mm / sec. Measured value: The first 30 mm of the tape displacement is ignored and the subsequent measured values of 20 mm are averaged.

Preparation Example 6
After adding and dispersing the aqueous dispersion of the resin composite 1 and silica sand in ion-exchanged water, a thickener is added to adjust the viscosity to approximately 800 mPa · s, and then a curing agent is added, The intermediate layer coating composition B3 was prepared. Table 5 shows mass ratios of components in the obtained intermediate layer coating composition B3.

Preparation Example 7
An intermediate layer coating composition B4 was prepared in the same manner as in Preparation Example 6 except that the resin composite 1 was changed to the resin composite 2. Table 5 shows the mass ratio of each component in the obtained intermediate layer coating composition B4.

Example 8 and Comparative Example 2
The intermediate layer coating composition B3 or B4 was spray-coated on a 150 mm × 65 mm × 3 mm slate plate coated with an acrylic paint so as to have a coating amount of 150 g / m ² and dried at 110 ° C. for 15 minutes. Followed by a photocatalyst layer coating composition T1 was applied to a 12.5 g / m ^2, to obtain a laminate coating.
About the obtained laminated body coating film, the residual amount of the photocatalyst layer after performing the following weather resistance tests was evaluated. The results are shown in FIGS. The laminate coating film obtained in Example 8 was not peeled because the photocatalyst layer covered the entire surface of the coating film surface even after the weather resistance test. On the other hand, the laminate coating film obtained in Comparative Example 2 had the photocatalyst layer peeled off about half after the weather resistance test.

(Weather resistance test)
Using a sunshine weather meter (S300, manufactured by Suga Test Instruments Co., Ltd.), a test for 1500 hours was performed under the conditions based on the former JIS K 5400 9.8.
(Evaluation)
The surface of the coating film was observed with a laser microscope (manufactured by Keyence Corporation, VK-8510) and an objective lens 150 times, and the remaining amount of the photocatalyst layer was observed.

Claims (12)

A laminate coating film comprising a substrate, an intermediate layer formed on the substrate, and a photocatalyst layer formed on the intermediate layer,
The intermediate layer includes a particulate resin composite in which an inorganic polymer is segregated on the surface,
A laminate coating film, wherein the photocatalyst layer contains photocatalyst particles and inorganic oxide particles. The laminate coating film according to claim 1, wherein the resin composite has a core-shell structure. The laminate coating film according to claim 2, wherein the resin composite has a shell part thickness of 5.0 nm or more. The laminate coating film according to any one of claims 1 to 3, wherein the resin composite contains a fluoropolymer, a (meth) acrylic polymer, and an inorganic polymer. The laminate coating film according to any one of claims 1 to 4, wherein the inorganic polymer is polysiloxane. The laminate coating according to claim 4 or 5, wherein the fluoropolymer comprises vinylidene fluoride units and at least one fluoroolefin unit selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene. film. The laminate according to any one of claims 4 to 6, wherein the (meth) acrylic polymer contains at least one acrylic monomer unit selected from the group consisting of acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester. Paint film. The laminate coating film according to any one of claims 4 to 7, wherein the (meth) acrylic polymer is obtained by seed polymerization of a (meth) acrylic monomer in an aqueous dispersion containing a fluoropolymer. The laminate coating film according to claim 8, wherein the resin composite is obtained by condensation polymerization of silanol in the presence of a (meth) acrylic polymer obtained by seed polymerization. The photocatalyst layer is more than 1% by weight and less than 20% by weight of photocatalyst particles;
Inorganic oxide particles greater than 70% by weight and less than 99% by weight;
The laminated body coating film in any one of Claims 1-9 containing 0 mass% or more and less than 10 mass% inorganic binder. The laminate coating film according to any one of claims 1 to 10, wherein the inorganic oxide particles have an average particle size of 50 nm or less. The laminate coating film according to any one of claims 1 to 11, which is used as an exterior material.

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