JP2023150155A - Coated body and coating composition - Google Patents

Abstract

To provide a coated body equipped with a surface layer having water repellency with excellent lastingness.SOLUTION: A coated body is equipped with a functional layer on surface, the coated body has irregularity on the surface, where the functional layer is equipped with a functional layer 1 having the average film thickness 0.01 to 20 μm which contains particles A of the average particle diameter 5nm to 500nm, particles B of the average particle diameter 1 μm to 30 μm, and a binder component, and the amount of the binder component in the functional layer 1 is within the range of 5 to 50 mass%.SELECTED DRAWING: None

Description

The present invention relates to a coated body and a coating composition, and particularly to a coated body having a surface layer with excellent long-lasting water repellency.

In recent years, low-pollution specifications have become widespread for building boards used as exterior wall materials for houses due to the spread of photocatalyst coatings and overcoat coatings. By making the surface of the paint film hydrophilic, these products have a self-cleaning function that allows them to be washed away with rainwater even if dirt adheres to the paint film, providing a sustainable aesthetic appearance in the exterior wall market where aesthetics are required. It's possible, and it's an excellent technique.

JP-A-9-228602 (Patent Document 1) describes an invention of a self-cleaning building material for exterior walls, which comprises a surface layer containing photocatalytic oxide particles on the surface of a base material for exterior walls. In Patent Document 1, when a building material for an exterior wall is formed with a surface layer containing a photocatalyst, the surface becomes highly hydrophilic when the photocatalyst is photoexcited. This makes it possible to provide a self-cleaning building material for exterior walls.

JP 2013-209832A (Patent Document 2) discloses a building board having a base coating layer, a clear coating layer, and an overcoat coating layer on a base material, the clear coating layer containing a fluorine component. A building board is described which is characterized in that it is formed by applying a clear paint. Patent Document 2 discloses that the fluorine-containing component is appropriately oriented at the interface between the clear coating layer and the overcoat coating layer, thereby improving the hydrophilic stability over time in a hydrophilic antifouling laminated coating film that has self-cleaning ability. It is stated that this can be improved.

JP-A-2011-246603 (Patent Document 3) discloses a paint characterized by containing hydrophilic metal oxide fine particles with an average particle diameter of 10 to 300 nm, a binder component, a surface tension modifier, and a solvent component. A composition is described. In Patent Document 3, by blending hydrophilic metal oxide fine particles with an average particle size of 10 to 300 nm, appearance, hydrophilicity, and antifouling properties are improved compared to the case without blending. It describes what you can do.

However, while making the surface of the paint film hydrophilic makes it easier for rainwater to spread, it also means that the paint film retains water for a longer time, making it more susceptible to algae, mold, and ultraviolet rays. Also, in cold regions, it has the disadvantage of being susceptible to frost damage. In addition, the method of making the surface of the coating film hydrophilic using a photocatalyst has the problems of being difficult to recoat and not being effective in areas that are not exposed to light.

Furthermore, apart from the method of making the surface of the coating film hydrophilic, a method of making the surface of the coating film water repellent is also known. By making the surface of the coating film water-repellent, it can be expected to have the effect of preventing pollution from airborne particles.

JP-A-2005-15727 (Patent Document 4) discloses an emulsion (A) containing an alkyl alkoxysilane (a), an organopolysiloxane (b) having an alkoxy group, and an emulsifier (c) as active ingredients, and a water solubility of 5. % or more of an organic solvent (B) and a nonvolatile content within the range of 2 to 50%. Patent Document 4 describes that this composition can form a film with very good coating workability and excellent water repellency.

Japanese Patent Application Publication No. 9-228602 Japanese Patent Application Publication No. 2013-209832 Japanese Patent Application Publication No. 2011-246603 Japanese Patent Application Publication No. 2005-15727

Although Patent Documents 1 to 4 are technologies that can achieve a certain degree of stain resistance, further performance improvements are required when considering the expanded use of ceramic siding materials in cold regions and life cycle costs. For example, there is a need for a building board that has a water-repellent coating on its surface that makes it difficult for airborne substances to adhere to it and allows water to easily slide off the coating surface, and that can be maintained for a long time.

Therefore, an object of the present invention is to provide a coated body having a surface layer with excellent water repellency and excellent durability. Another object of the present invention is to provide a coating composition capable of forming a water-repellent coating film with excellent durability.

In order to solve the above problem, the inventor of the present invention made extensive studies and found that it is possible to form irregularities on the surface of a coating film with an average thickness of 0.01 to 20 μm using two types of particles having specific particle sizes. In addition, by controlling the amount of binder component in the coating film to a specific amount, it is possible to prevent particles from falling off while forming surface irregularities, so it can be used for a long period of time. It was discovered that water repellency can be exhibited, and the present invention was completed.

Therefore, the coated body of the present invention is a coated body having a functional layer on the surface, the coated body has unevenness on the surface, and the functional layer has particles A having an average particle diameter of 5 nm to 500 nm, and an average particle diameter of 5 nm to 500 nm. A functional layer 1 with an average thickness of 0.01 to 20 μm containing particles B with a particle diameter of 1 μm to 30 μm and a binder component, and the amount of the binder component in the functional layer 1 is within the range of 5 to 50% by mass. It is a painted body characterized by this.

In a preferred embodiment of the coated body of the present invention, the water contact angle on the surface of the functional layer is within the range of 100° to 170°.

In another preferred embodiment of the coated body of the present invention, the ratio of the particles A to the particles B in the functional layer 1 is within the range of 40:60 to 95:5 in terms of mass ratio.

In another preferred embodiment of the coated body of the present invention, the binder component contains a compound represented by formula (1) as a structural unit.
Formula (1): R1 _n Si(OR2) _4-n
(In the formula, R1 is an organic group having 1 to 8 carbon atoms, R2 is an alkyl group having 1 to 5 carbon atoms, and n is 1 or 2.)

In another preferred embodiment of the coated body of the present invention, the functional layer further includes a functional layer 2 containing a water repellent agent laminated on the functional layer 1.

In another preferred embodiment of the coated body of the present invention, the functional layer 1 and/or the functional layer 2 contain an adhesion promoter.

In another preferred embodiment of the coated body of the present invention, the particles A are hydrophilic silica.

Further, the coating composition of the present invention includes particles A having an average particle diameter of 5 nm to 500 nm, particles B having an average particle diameter of 1 μm to 30 μm, and a binder component, and the amount of the binder component in the coating film forming components is This is a coating composition characterized in that the content is in the range of 5 to 50% by mass.

According to the coated body of the present invention, it is possible to provide a coated body having a surface layer with excellent water repellency and excellent durability. Further, according to the coating composition of the present invention, a coating composition capable of forming a coating film with excellent long-lasting water repellency can be provided.

The present invention will be explained in detail below.

One embodiment of the present invention is a coated body having a functional layer on its surface. In this specification, this coated body is also referred to as the "coated body of the present invention." The coated body of the present invention has an uneven surface and can exhibit water repellency by using two types of particles with different particle sizes. Therefore, in the present invention, the functional layer is a layer that has at least water repellency.

The coated body of the present invention has a functional layer on the surface layer. Here, the functional layer may be one layer or multiple layers, and is preferably a functional layer consisting of at least two layers.

In the coated body of the present invention, the functional layer has an average thickness of 0.01 to 20 μm, and includes particles A with an average particle diameter of 5 nm to 500 nm, particles B with an average particle diameter of 1 μm to 30 μm, and a binder component. It is preferable to include a functional layer in which the amount of the binder component in the functional layer is within the range of 5 to 50% by mass. The coated body of the present invention has irregularities on the surface at least due to the presence of this functional layer. In this specification, the functional layer containing particles A, particles B, and a binder component is also referred to as "functional layer 1."

The coated body of the present invention uses two types of particles A and B having specific particle sizes in the functional layer 1, which has a relatively small film thickness, to form irregularities on the surface of the coated body and improve water repellency. This makes it difficult for airborne substances to adhere to the surface of the painted body. Further, since the functional layer 1 contains a specific amount of a binder component, it is possible to prevent particles from falling off while forming surface irregularities, and water repellency can be exhibited for a long period of time.

The coated body of the present invention has an uneven surface, and the surface roughness is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm.

In this specification, surface roughness is ten-point average roughness (Rzjis) measured in accordance with JIS B 0601:2001.

The average thickness of the functional layer 1 is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, and even more preferably 1 to 5 μm. If the functional layer 1 is too thin, the amount of paint applied will be small, and water repellency may not be stably exhibited. Furthermore, if the functional layer 1 is too thick, there is a risk that the functional layer will become cloudy or that the functional layer will easily fall off.

In this specification, the average film thickness of the functional layer is a value obtained by observing the cross section of the coating film with a scanning electron microscope, and is the average value of the measurement results of 100 points randomly selected from the photographed images. It is determined by

Particle A is a nano-order particle, and its average particle diameter is 5 nm to 500 nm, preferably 10 nm to 200 nm, more preferably 20 nm to 120 nm, particularly preferably 30 to 80 nm. . Further, the particles B are particles on the micron order, and the average particle diameter is 1 μm to 30 μm, preferably 2 μm to 30 μm, more preferably 5 μm to 20 μm, and preferably 5 μm to 10 μm. Most preferred. By combining such nano-order particles and micron-order particles, fine irregularities can be formed on the surface and water repellency can be imparted to the functional layer. Further, the average particle diameter of the particles B is preferably larger than the average thickness of the functional layer 1 from the viewpoint of forming irregularities on the surface.

In this specification, the average particle diameter of Particle A and Particle B refers to the 50% particle diameter (D ₅₀ ) of the volume-based particle size distribution, and is measured using a particle size distribution measuring device (for example, a laser diffraction/scattering type particle size distribution measuring device). It can be determined from the particle size distribution measured by The particle size here is expressed as a spherical equivalent diameter determined by laser diffraction/scattering method.

The amount of particles A in the functional layer 1 is preferably 25 to 90% by weight, more preferably 30 to 85% by weight. The amount of particles B in the functional layer 1 is preferably 2.5 to 47.5% by weight, more preferably 5 to 40% by weight. Further, the ratio of particles A to particles B in the functional layer 1, that is, the ratio of particles A to particles B, is preferably within the range of 40:60 to 95:5, and 50:50 to 85: More preferably, it is within the range of 15. By setting the amount of particles A in the functional layer 1 to 25% by mass or more, it becomes easier to form a fine uneven structure on the surface of the coating film. Furthermore, by setting the amount of particles B in functional layer 1 to 2.5% by mass or more, a fractal structure is formed on the surface of the coating film, and when water adheres to the coating film, the water is absorbed by the surface tension of the water. A water-repellent structure can be formed that does not get into the recesses.

Particles A and Particles B can be any of inorganic particles, organic particles, and organic-inorganic composite particles, and may be porous particles. Further, the shape is not particularly limited, and in addition to being spherical, it may be non-spherical such as angular, needle-like, and scale-like. Examples of inorganic particles include heavy calcium carbonate, kaolin, clay, china clay, china clay, talc, barite powder, barium sulfate, barium carbonate, magnesium carbonate, silica particles, aluminum hydroxide, marble, granite, serpentine, and granite. Examples include particles of fluorite, agarite, feldspar, limestone, silica, silica sand, crushed stone, mica, siliceous shale, ceramic, glass, metal, and the like. Examples of organic particles and organic-inorganic composite particles include polyethylene, polypropylene, polyacrylic acid alkyl ester, polymethacrylic acid alkyl ester, polytetrafluoroethylene, tetrafluoroethylene/methyl vinyl ether copolymer, and crosslinked polydimethylsiloxane. Examples include particles such as. Particle A and particle B may be made of the same material, but are preferably made of different materials. Further, each of the particles A and B may be used alone or in combination of two or more types.

Preferably, particles A are metal oxide particles. Examples of metal oxide particles include silica particles, alumina particles, mica particles, talc particles, titanium oxide particles, cerium oxide particles, zinc oxide particles, calcium oxide particles, and among these, silica particles are preferred. Although it is known that hydrophobic silica particles are used as the silica particles from the viewpoint of water repellency, in the present invention, it is preferable to use hydrophilic silica, particularly colloidal silica. By using hydrophilic silica particles as particles A, the transparency of the functional layer can be improved, and for example, it is possible to provide a coated body that takes advantage of the design of the lower design layer. Further, by using colloidal silica as particles A, the dispersion stability of the coating material is improved, and it becomes easier to form irregularities on the surface of the coated body.

Particles B are preferably resin beads, inorganic particles, porous particles, or glass beads, and more preferably resin beads. By using resin beads, porous particles, or glass beads with low specific gravity and excellent transparency as particles B, the dispersion stability in the functional layer is improved, the formation of an uneven structure is facilitated, and the transparency of the functional layer is improved. It becomes possible to form a water-repellent layer that takes advantage of the design of the coating layer and base material layer on the surface on which the functional layer is formed. Furthermore, by using highly hydrophobic resin beads as particles B, the water repellency of the functional layer can be further improved from both the water repellent effect due to the uneven structure and the water repellent effect due to the resin beads.

The binder component is a component that forms the continuous phase of the functional layer, and can prevent particles contained in the functional layer from falling off. This makes it possible to maintain the water repellency of particles A and B over a long period of time. Further, by using a binder component, adhesion to the base material and the coating layer can be improved.

The amount of the binder component in the functional layer 1 is within the range of 5 to 50% by mass, preferably within the range of 10 to 40% by mass, and more preferably within the range of 15 to 35% by mass. . By increasing the amount of the binder component, the sustainability of water repellency and adhesion of particles A and B can be improved. On the other hand, if the binder component is too large, it may become difficult to form surface irregularities. The binder component may be used alone or in combination of two or more types.

Examples of the binder component include acrylic resin, silicone resin, acrylic silicone resin, styrene-acrylic copolymer resin, polyester resin, fluororesin, rosin resin, petroleum resin, coumaron resin, phenol resin, urethane resin, melamine resin, urea resin, Epoxy resins, cellulose resins, xylene resins, alkyd resins, aliphatic hydrocarbon resins, butyral resins, maleic acid resins, fumaric acid resins, vinyl resins, amine resins, ketimine resins, and resins modified from these resins (modified resins) Examples include resins such as. Various modifications are known for resin modification, such as alkyl modification, alkyl ether modification, alkylphenol novolak modification, acrylic modification, fatty acid modification, urethane modification, amino modification, isocyanate modification, silicone modification, and allyl group-based modification. Examples include graft modification. Further, a resin crosslinked with a crosslinking agent is also included in the binder component.

The binder component has the formula (1): R1 _n Si(OR2) _4-n (wherein, R1 is an organic group having 1 to 8 carbon atoms, R2 is an alkyl group having 1 to 5 carbon atoms, and n is 1 or 2) as a structural unit (such as a repeating unit), and for example, it is preferable to contain a resin containing a compound represented by formula (1) as a structural unit. When the binder component contains the compound represented by formula (1) as a structural unit, a film with excellent weather resistance can be formed. Furthermore, when particle A is a silica particle or particle B is a resin bead or glass bead, the dispersion stability and fixation with particles A and B can be improved, and the sustainability of water repellency and It is also effective in improving transparency.

In formula (1), examples of the organic group R1 include an alkyl group, a cycloalkyl group, an aryl group, and a vinyl group. Further, the alkyl group may be straight chain or branched, and examples of such alkyl groups include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and i-butyl group. , s-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, etc. Preferred alkyl groups have 1 to 4 carbon atoms. Preferred examples of the cycloalkyl group include a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the aryl group include a phenyl group. These organic groups may be optionally substituted with a substituent. Examples of such substituents include halogen atoms (eg, chlorine atoms, bromine atoms, fluorine atoms), (meth)acryloyl groups, mercapto groups, alicyclic groups, and the like.

In formula (1), the alkyl group of R2 may be linear or branched, and examples of such alkyl groups include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, Examples include i-butyl group, s-butyl group, t-butyl group, and pentyl group. Preferred alkyl groups have 1 to 2 carbon atoms.

Specific examples of the compound represented by formula (1) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i- Propyltrimethoxysilane, i-propyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane , 3,3,3-trifluoropropyltriethoxysilane, cyclohexyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane Ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, dimethyldipropoxysilane, etc. can be mentioned. Preferred are methyltrimethoxysilane, methyltriethoxysilane, and dimethyldimethoxysilane.

When obtaining a binder component containing the compound represented by formula (1) as a structural unit, the compound represented by formula (1) may be used alone or in combination of two or more types. Alternatively, a partially hydrolyzed condensate of the compound represented by formula (1) may be used. The weight average molecular weight of this partially hydrolyzed condensate in terms of polystyrene is, for example, 300 to 5,000, preferably 500 to 3,000. By using a partial hydrocondensate having such a molecular weight, a film with good adhesion can be obtained without deteriorating storage stability. Further, it is appropriate that the partially hydrolyzed condensate of the compound represented by formula (1) has one or more, preferably 3 to 30, -OH or -OR2 groups bonded to a silicon atom. . Specific examples of the compound represented by formula (1) include commercially available products KR-211, KR-212, KR-213, KR-214, KR-216, and KR-218 manufactured by Shin-Etsu Chemical; Toshiba Silicone; Examples include TSR-145, TSR-160, TSR-165, YR-3187, etc. manufactured by the company.

When obtaining a binder component containing the compound represented by formula (1) as a constitutional unit, the compound represented by formula (1) and/or its partially hydrolyzed condensate (provided that n in formula (1) is 1) ) (A) and the compound represented by formula (1) and/or its partially hydrolyzed condensate (provided that n in formula (1) is 2) (B) are used together, the mass ratio (A When :B) is, for example, 50:50 to 100:0, preferably 60:40 to 95:5, the reaction will be stable during the subsequent hydrolytic condensation reaction, and a film with good crack resistance will be formed. can do.

The amount of the compound represented by formula (1) in the binder component is preferably 2 to 90% by weight, more preferably 5 to 80% by weight.

The binder component preferably contains an organic-inorganic composite resin, more preferably an organic-inorganic composite resin containing an organosilane and/or a partially hydrolyzed condensate thereof, and a silyl group-containing vinyl resin as a constituent unit, It is more preferable to include an organic-inorganic composite resin containing a compound represented by formula (1) and/or a partially hydrolyzed condensate thereof, and a silyl group-containing vinyl resin as a constituent unit. The binder component preferably has an organic component from the viewpoint of water repellency sustainability and adhesion, but by using an organic-inorganic composite resin as the binder component, it is possible to form a film with even better weather resistance. In addition, organic-inorganic composite resin is a resin that has excellent transparency because it contains an inorganic component in addition to an organic component, and the inorganic component easily reacts with inorganic oxide particles and immobilizes the inorganic oxide particles. You can also.

The amount of the organic-inorganic composite resin in the binder component is preferably 20% by mass or more, more preferably 50% by mass or more. The organic-inorganic composite resin may be used alone or in combination of two or more types.

The silyl group-containing vinyl resin preferably has a silyl group having a silicon atom bonded to a hydrolyzable silyl group or a hydroxyl group, and silicon bonded to a hydrolyzable silyl group or a hydroxyl group at the terminal or side chain of the vinyl resin. It is more preferable to have at least one silyl group having an atom in one molecule of the resin, and one molecule of the resin has a silyl group having a silicon atom bonded to a hydrolyzable silyl group or a hydroxyl group at the terminal or side chain of the vinyl resin. It is more preferable to have two or more of them.

The silyl group of the silyl group-containing vinyl resin has the general formula -SiX _P (R3) _(3-P) (wherein, X is an alkoxy group, an acyloxy group, a halogen group, a ketoximate group, a mercapto group, an alkenyloxy group, a hydrolyzable group such as a phenoxy group, or a hydroxyl group, R3 is hydrogen or a monovalent hydrocarbon group such as an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, and P is 1 to 3 is an integer of ).

The silyl group-containing vinyl resin has, for example, the general formula (X) _P (R3) _(3-P) Si-H (wherein, X, R3 and P are the general formula of the above silyl group). It is produced by reacting a hydrosilane compound represented by (has the same meaning as ) with a vinyl resin having a carbon-carbon double bond according to a conventional method.

Here, representative examples of the hydrosilane compound include methyldichlorohydrosilane, methyldiethoxyhydrosilane, methyldiacetoxyhydrosilane, and the like. The appropriate amount of the hydrosilane compound to be used when producing a silyl group-containing vinyl resin is a molar amount that is 0.5 to 2 times the number of carbon-carbon double bonds contained in the vinyl resin. .

Vinyl resins contain, for example, carboxylic acids such as (meth)acrylic acid, itaconic acid, and fumaric acid, or acid anhydrides such as maleic anhydride as essential monomer units, and further include methyl (meth)acrylate, (meth)acrylate, etc. (Meth)acrylic acid esters such as ethyl acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylic acid, acrylonitrile, styrene, α-methylstyrene, vinyl acetate, vinyl propionate The copolymer is preferably a copolymer containing a vinyl monomer selected from the group consisting of It becomes possible to introduce carbon-carbon double bonds for hydrosilylation reactions into the resin.

In addition, silyl group-containing vinyl resins include vinyl monomers containing the above-mentioned carboxylic acids or acid anhydrides, and hydroxyl groups such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxyvinyl ether. Containing monomers, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, β-(meth)acryloxyethyltrimethoxysilane, β-(meth)acryloxyethyltriethoxy Silane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, γ-(meth)acryloxypropylmethyldipropoxysilane, γ-(meth)acryloxybutylphenyldimethoxy It can also be prepared by radical polymerization with a silyl group-containing vinyl compound such as silane, γ-(meth)acryloxypropyldimethylmethoxysilane, and γ-(meth)acryloxypropyldiethylmethoxysilane. Specific examples of these silyl group-containing vinyl resins include Kanekazemurak, a commercially available product manufactured by Kanekafuchi Kagaku Kogyo Co., Ltd., and the like.

Furthermore, when the silyl group-containing vinyl resin is a water-dispersible resin, it is also possible to prepare the water-dispersible silyl group-containing vinyl resin as described below.

The acid value of the silyl group-containing vinyl resin is preferably 20 to 150 mgKOH/g, more preferably 50 to 120 mgKOH/g. When the acid value of the silyl group-containing vinyl resin is within the range specified above, the storage stability of the obtained organic-inorganic composite resin can be improved, and the water resistance and hot water resistance of the obtained film can be improved. You can also do that. In this specification, the acid value of a resin means the number of mg of potassium hydroxide required to neutralize 1 g of resin.

The silyl group-containing vinyl resin preferably has a polystyrene equivalent weight average molecular weight of 1,000 to 50,000.

The amount of the silyl group-containing vinyl resin in the binder component is preferably 5% by mass or more, more preferably 50% by mass or more.

Next, a method for producing an organic-inorganic composite resin containing a compound represented by formula (1) and/or a partially hydrolyzed condensate thereof, and a silyl group-containing vinyl resin as a constituent unit will be described. In this specification, this organic-inorganic composite resin is also referred to as "organic-inorganic composite resin (a)."

In one embodiment of the method for producing an organic-inorganic composite resin (a), particularly an aqueous dispersion thereof, first, a compound represented by formula (1) and/or a partially hydrolyzed condensate thereof (hereinafter, component (a-1) ) and a silyl group-containing vinyl resin (hereinafter also referred to as component (a-2)) in the presence of water and a catalyst to cause hydrolysis and condensation reactions. The mixing ratio of component (a-1) and component (a-2) is such that the amount of component (a-2) is 5 to 200 parts by mass, preferably 10 to 200 parts by mass, per 100 parts by mass of component (a-1). A suitable amount is 150 parts by mass. If the amount of component (a-2) is less than 5 parts by mass, the appearance, crack resistance, frost damage resistance, alkali resistance, etc. of the resulting coating film may deteriorate, and conversely, component (a-2) If the amount exceeds 200 parts by mass, the resulting film may have poor weather resistance, stain resistance, etc.

The amount of water added to the mixture of component (a-1) and component (a-2) is determined so that the amount of water added to the mixture of component (a-1) and component (a-2) is determined by the amount of water that is The amount is sufficient to hydrolyze and condensate preferably 45 to 100%, more preferably 50 to 90% of the hydrolyzable groups, specifically 0.0 of the total number of hydrolyzable groups in the mixture. An appropriate amount is 45 to 1.0 times, preferably 0.5 to 0.9 times the number of moles. The reason why 45% or more is preferable is that the organic-inorganic composite resin (a) has good storage stability when it becomes an aqueous dispersion (emulsion), and it also provides a highly transparent film when used as a coating material. This is because formation is possible.

Examples of the catalyst added to the mixture of component (a-1) and component (a-2) include inorganic acids such as nitric acid and hydrochloric acid, and organic acids such as acetic acid, formic acid and propionic acid. The appropriate amount of catalyst to be added is such that the pH of the mixture becomes 3 to 6. For the hydrolysis reaction, a mixture of component (a-1) and component (a-2) is heated at 40 to 80°C, preferably 45 to 65°C, for 2 to 10 hours in the presence of water and a catalyst. A method of reacting while stirring is suitable, but the method is not limited to this method.

Although it is possible to carry out the hydrolytic condensation reaction between component (a-1) and component (a-2) in one step as described above, from the viewpoint of storage stability of the product, the following It is preferable to carry out the reaction in two stages. That is, in the first step, in the presence of water and a catalyst, 40 to 80%, preferably 40 to 80%, of the hydrolyzable groups initially present in the mixture of component (a-1) and component (a-2) are removed. is reacted with stirring at 40 to 80°C, preferably 45 to 65°C, for 1 to 8 hours so that 45 to 70% of the mixture undergoes a hydrolytic condensation reaction.

As a second step, following the first step, water and trialkoxyborane such as trimethoxyborane, triethoxyborane, tri-n-butoxyethyl acetate zirconium, di-n-butoxy(ethyl acetate) zirconium, tetratarakis (ethyl acetate) zirconium chelate compounds such as zirconium, titanium chelate compounds such as diisopropoxybis(acetylacetate)titanium, diisopropoxybis(ethylacetate)titanium, monoacetylacetatebis(ethylacetoacetate)aluminum, diisopropoxyethylacetate An organometallic compound catalyst such as an aluminum chelate compound such as aluminum acetate is added to cause hydrolysis and condensation reactions. The trialkoxyborane or organometallic compound catalyst used in the second step can promote the condensation reaction and improve the appearance, weather resistance, stain resistance, hot water resistance, etc. of the membrane.

The amount of water added in the second step is 45 to 100%, preferably 50 to 90% of the hydrolyzable groups initially present in the mixture of component (a-1) and component (a-2). % is sufficient for hydrolysis and condensation reactions. The amount of the catalyst added in the second step is based on 100 parts by mass of the total amount of the reactant obtained in the first step and the remaining unreacted components (a-1) and (a-2). A suitable amount is 0.001 to 5 parts by weight, preferably 0.005 to 2 parts by weight. The hydrolytic condensation reaction in the second stage is suitably carried out at 40 to 80°C for 2 to 5 hours as in the first stage.

Note that the hydrolytic condensation reaction product is in a solution state due to the alcohol content produced by the reaction, or due to the alcohol content and an organic solvent described below added as necessary. A neutralizing agent is added to the solution of the organic-inorganic composite resin (a), which is the reaction product obtained in this way, and the neutralizing agent is uniformly dispersed. After neutralization, water is added, or the neutralizing agent and water are combined. They are added simultaneously and forcedly dispersed by stirring to obtain an aqueous dispersion (emulsion).

The amount of the neutralizing agent is appropriate to neutralize 50 to 100%, preferably 70 to 100%, of the acid groups in the organic-inorganic composite resin as a reactant so as to obtain a stable emulsion. . Note that typical neutralizing agents include triethylamine, triethanolamine, dimethylethanolamine, monoethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, and morpholine.

The amount of water added after neutralization is arbitrarily determined in consideration of painting workability, etc., but it is usually appropriate to use an amount that will bring the solid content of the paint to 10 to 70% by mass. Note that in the aqueous dispersion of the organic-inorganic composite resin (a) thus obtained, the alcohol produced by the above-mentioned hydrolytic condensation reaction remains. Therefore, if the aqueous dispersion is used as it is in a paint, volatile organic components (VOC) will increase, so it is preferable to remove the alcohol content under reduced pressure according to a conventional method.

The organic-inorganic composite resin is preferably crosslinked (or cured) with a hydrolytic condensation-reactive alkoxysilane having an amino group, and a hydrolytic condensation-reactive alkoxysilane having an amino group and the amino group of the alkoxysilane. It is more preferable that it be crosslinked (or cured) with a compound having a reactive epoxy group in its molecule. By crosslinking or curing the organic-inorganic composite resin in this manner, a film with excellent hot water resistance, alkali resistance, weather resistance, stain resistance, solvent resistance, crack resistance, etc. can be formed. In this specification, this hydrolytic condensation alkoxysilane having an amino group is also referred to as "alkoxysilane (b)" or "component (b)", and the epoxy group having reactivity with the amino group of the alkoxysilane is referred to as "alkoxysilane (b)" or "component (b)". The compound contained in the molecule is also referred to as "compound (c)" or "component (c)."

Component (b) is an alkoxysilane having an amino group and capable of a hydrolytic condensation reaction, and specifically has the formula (2): (R6-NH-R5-) _n Si(OR4) _4-n (in the formula , R4 is an alkyl group having 1 to 5 carbon atoms, R5 is an alkylene group having 1 to 5 carbon atoms, and R6 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 5 to 8 carbon atoms. An amino group-containing alkoxysilane represented by a cycloalkyl group, an aryl group having 6 to 8 carbon atoms, or a substituted or unsubstituted amino group, where n is 1 or 2, can be preferably used. Alkoxysilane (b) may be used alone or in combination of two or more.

In formula (2), the alkyl group as R4 may be linear or branched, and examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group. group, s-butyl group, t-butyl group, pentyl group, etc. Preferred alkyl groups have 1 to 2 carbon atoms. The alkylene group as R5 may be linear or branched, and examples include a methylene group, an ethylene group, a propylene group, and the like. The alkyl group as R6 is the same as in the case of R4. Furthermore, examples of the cycloalkyl group as R6 include a cyclohexyl group and a cycloheptyl group. Further, examples of the aryl group as R6 include a phenyl group. Furthermore, examples of the amino group as R6 include those in which one or both of the hydrogen atoms in the amino group are substituted with, for example, an alkyl group having 1 to 5 carbon atoms.

Examples of the alkoxysilane (b) include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl )-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-cyclohexyl-γ-aminopropyltrimethoxysilane, N-cyclohexyl-γ-aminopropyltri Examples include ethoxysilane, γ-(2-aminoethyl)-aminopropyltrimethoxysilane, γ-(2-aminoethyl)-aminopropylmethyldimethoxysilane, and γ-anilinopropyltrimethoxysilane.

The amount of alkoxysilane (b) is preferably 0.5 to 30 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the organic-inorganic composite resin. If the amount of alkoxysilane (b) is too small, the curability and stain resistance of the resulting film may be reduced; on the other hand, if it is too large, the hot water resistance and crack resistance may be reduced.

Component (c) is a compound having an epoxy group in its molecule that is reactive with the amino group in alkoxysilane (b). As the compound (c), for example, epoxy group-containing alkoxysilanes, alkyl glycidyl ethers and esters, cyclopoxy compounds, bisphenol AF-based low molecular weight epoxy resins, or emulsions thereof can be used. Compound (c) may be used alone or in combination of two or more.

Specific examples of compound (c) include γ-glycidoxypropyltrimexysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. , γ-glycidoxypropyltriisopropenyloxysilane, γ-glycidoxypropyltriiminooxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, γ-isonanatepropyltriisopropenyloxysilane and adducts with glycidol, butyl glycidyl ether, polyoxyethylene glycidyl ether, Cardular E (trade name manufactured by Shell Co., Ltd.), butylphenyl glycidyl ether, Epicote 815, 828, 834 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.), etc. These emulsions are representative examples. Among the compounds (c), it is preferable to use an epoxy group-containing alkoxysilane compound having a hydrolyzable silyl group because the curability of the film is improved and heat resistance, alkali resistance, etc. are improved.

The amount of compound (c) is such that the total number of epoxy groups in compound (c) is preferably 0.1 to 2.0 times, more preferably A suitable amount is 0.2 to 1.2 times as much. If the amount of compound (c) is too small, the hot water resistance etc. of the resulting film may be reduced; on the other hand, if it is too large, the weather resistance, crack resistance, etc. of the coating film may be reduced.

When alkoxysilane (b) or compound (c) is used, it is preferable to mix it with an aqueous dispersion of an organic-inorganic composite resin and disperse it immediately before coating. The alkoxysilane (b) and the compound (c) act as a curing agent for the organic-inorganic composite resin, and the silyl group in the alkoxysilane (b) and the silyl group in the compound (c) (if present) are organic and inorganic. A hydrolytic condensation reaction occurs with the silyl groups remaining in the composite resin, and the amino group in the alkoxysilane (b) reacts with the epoxy group in the compound (c).

The binder component may include a water-dispersible resin. As used herein, a "water-dispersible resin" is a resin that can be distributed in water to form a heterogeneous system (eg, an emulsion or suspension). It is preferable that the water-dispersible resin includes an emulsion resin. The emulsion resin is a water-dispersible resin that can have a large molecular weight and has excellent dispersion stability. For example, there are cases where the above-mentioned organic-inorganic composite resin or silyl group-containing vinyl resin is a water-dispersible resin, or cases where a water-dispersible resin is included as a resin other than the organic-inorganic composite resin or silyl group-containing vinyl resin. .

The amount of water-dispersible resin in the binder component is, for example, 50% by mass or more, preferably 80% by mass or more. The water-dispersible resins may be used alone or in combination of two or more.

It is preferable that the water-dispersible resin contains an acrylic component as a structural unit (repeat unit, etc.). In this specification, "acrylic component" refers to acrylic acid, methacrylic acid, and derivatives thereof (for example, esters of acrylic acid and methacrylic acid, compounds having a (meth)acryloyl group such as amides, acrylic nitrile, methacrylic nitrile, etc. ). The acrylic component may be used alone or in combination of two or more.

Specific examples of the acrylic component include, but are not limited to, acrylic acid, methacrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. , n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate , n-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, n-lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, 2-methoxy Ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate , (meth)acrylamide, diacetone (meth)acrylamide, N-monomethyl (meth)acrylamide, N-monoethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-n-propyl (meth)acrylamide, N - Isopropyl (meth)acrylamide, methylenebis(meth)acrylamide, N-methylol (meth)acrylamide, N-butoxymethyl (meth)acrylamide, dimethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, Diacetone (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, ethylene glycol (meth)acrylate, ethylene glycol methoxy (meth)acrylate, diethylene glycol (meth)acrylate, diethylene glycol methoxy (meth)acrylate, tri- Fluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-methylcyclohexyl (meth)acrylate, Cyclohexylmethyl (meth)acrylate, cyclohexylethyl (meth)acrylate, cyclohexylpropyl (meth)acrylate, 4-methylcyclohexylmethyl (meth)acrylate, ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate , 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate and the like.

As used herein, the term (meth)acrylate means methacrylate or acrylate. For example, 2-ethylhexyl (meth)acrylate is 2-ethylhexyl acrylate or 2-ethylhexyl methacrylate. In addition, there are cases where (meth)acrylates are given a prefix indicating that they are plural, such as di(meth)acrylate, tri(meth)acrylate, etc., but in this case each (meth)acrylate is , may be the same or different.

In addition to acrylic resins, water-dispersible resins containing acrylic components as constituent units include various modified acrylic resins such as acrylic styrene resins, acrylic silicone resins, fluorine-modified acrylic resins, fatty acid-modified acrylic resins, urethane-modified acrylic resins, and epoxy-modified acrylic resins. Also includes resin.

The amount of the acrylic component in the water-dispersible resin is preferably 10% by mass or more, more preferably 20% by mass or more.

The water-dispersible resin can contain a non-acrylic component as a structural unit (such as a repeating unit). Non-acrylic components are components other than acrylic components, and include, in addition to styrene, carboxyl group-containing monomers such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, and vinyl versatic acid. Aromatic monomers such as methylstyrene, chlorostyrene, methoxystyrene, and vinyltoluene; Olefinic monomers such as ethylene and propylene; Vinyl monomers such as vinyl acetate and vinyl chloride; Amide monomers such as maleic acid amide; Alkoxysilyl group-containing monomers such as vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane, and vinylmethyldiethoxysilane; examples include dialkyl fumarate, allyl alcohol, vinylpyridine, butadiene, and the like. The non-acrylic components may be used alone or in combination of two or more.

It is preferable that the water-dispersible resin contains a silane coupling agent as a structural unit (repeat unit, etc.). Here, the silane coupling agent may be either an acrylic component or a non-acrylic component, but is preferably an acrylic component. Examples of the silane coupling agent that can serve as a structural unit of the water-dispersible resin include a silane coupling agent having a polymerizable group. Examples of the polymerizable group include polymerizable unsaturated groups such as alkenyl groups (vinyl group, allyl group, etc.), alkenylcarbonyl groups (eg, (meth)acryloyl group, crotonoyl group, etc.).

The silane coupling agent having a polymerizable group is, for example, a monomer having a silyl group to which a hydrolytically condensable group (e.g., an alkoxy group, a halogen atom) is bonded, and is represented by the following formula (3). Examples include compounds.
(R7) _n -Si-(R8) _4-n (3)
In formula (3), R7 represents a group having a polymerizable unsaturated bond group. R8 represents a hydrogen atom, a hydrolytic condensable group, a hydrocarbon group, or an epoxy group (an epoxy group-containing group), and at least one R8 represents a hydrolytic condensable group. n represents an integer from 1 to 3.

In formula (3), examples of the polymerizable unsaturated bond group in R7 include a vinyl group, an allyl group, and a (meth)acroyl group. Examples of the hydrocarbon group in R8 include an alkyl group and an aryl group (such as a phenyl group). Examples of the alkyl group include C _1-4 alkyl groups such as methyl group and ethyl group. In R8, examples of the hydrolytic condensable group include a hydroxyl group, a halogen atom (chlorine atom, etc.), an alkoxy group, an acyloxy group, an aryloxy group (phenoxy group, etc.), a mercapto group, and the like. Examples of the alkoxy group in R8 include C _1-4 alkoxy groups such as a methoxy group and an ethoxy group. Examples of the acyloxy group in R8 include C _2-4 acyloxy groups such as an acetyloxy group and a propionyloxy group.

Examples of the silane coupling agent having a polymerizable group include vinyl group-containing silanes {e.g., halosilanes having vinyl groups (e.g., vinyl mono- to trihalosilanes such as vinyl trichlorosilane), alkoxysilanes having vinyl groups [e.g. Alkoxysilanes (e.g., vinylmono- to trialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, preferably vinylmono- to tri-C _1-4 alkoxysilanes), vinylalkoxyalkoxysilanes (e.g., vinyltri(methoxyethoxy)silane, vinyltris (vinyl mono- to tri(C _1-4 alkoxyC _1-4 alkoxy) silanes such as (β-methoxyethoxy) silane), styryl group-containing silanes (for example, styryl mono- to trialkoxy silanes such as p-styryltrimethoxysilane, preferably styryl mono- to triC _1-4 alkoxysilane)], (meth)acryloyl group-containing silane {for example, alkoxysilane having a (meth)acryloyl group [for example, 3-(meth)acryloxypropyltrimethoxysilane, 3-( (meth)acryloxyalkyl mono- to trialkoxysilanes such as meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, preferably ( meth)acryloxy C _2-4 alkyl mono- to triC _1-4 alkoxysilane], hydroxysilane having a (meth)acryloyl group [e.g. 3-(meth)acryloxypropylhydroxysilane, 3-(meth)acryloxypropyl Examples include (meth)acryloxyalkylhydroxysilanes such as methylhydroxysilane, preferably (meth)acryloxyC _2-4 alkylhydroxysilanes.

The water-dispersible resin can be obtained by polymerization of monomer components serving as structural units, and is preferably obtained by emulsion polymerization of monomer components serving as structural units. The monomer components may be used alone or in combination of two or more.

The water-dispersible resin may be a resin having a single phase structure or a resin having a heterophase structure. In this specification, a resin having a heterophasic structure refers to a resin in which a plurality of sites with different compositions of monomer components exist in a domain or layered form, and among these, multiple sites with different compositions of monomer components exist. A resin that exists in layers is also referred to as a "resin with a multilayer structure." Further, the inner layer of the water-dispersible resin particles having a multilayer structure is referred to as a "core", and the outer layer is referred to as a "shell", and this is sometimes referred to as a resin having a core-shell structure. On the other hand, a resin having a single-phase structure is a resin in which the composition of monomer components is not divided into domains or layers, preferably a resin in which the composition of monomer components is uniformly distributed. Single-phase structures can be prepared by one-stage emulsion polymerization, and heterophasic structures can be prepared by multi-stage emulsion polymerization. The heterophasic structure has, for example, 2 to 5 layers or domains, preferably 2 to 3 layers or domains.

As a method for emulsion polymerization of the monomer components, emulsion polymerization may be performed in the presence of an emulsifier, for example, a method of mixing (dropping etc.) the monomer components in a solvent (solution) containing an emulsifier and polymerizing. Examples include a method in which monomer components that have been emulsified in advance are mixed (dropped, etc.) in a solvent and polymerized. As the solvent, usually an aqueous solvent such as water or a mixed solvent of water and a water-soluble organic solvent can be used. Examples of water-soluble organic solvents include alcohols such as C _1-4 alcohols such as methanol and ethanol. The water-soluble organic solvents may be used alone or in combination of two or more. Examples of methods for creating a heterophase structure include a multistage emulsion polymerization method in which the above-mentioned emulsion polymerization is repeated.

Examples of the emulsifier include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, amphoteric emulsifiers, polymer emulsifiers, and reactive emulsifiers. The emulsifiers may be used alone or in combination of two or more.

Examples of anionic emulsifiers include alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; alkylaryl sulfonate salts such as ammonium dodecylbenzene sulfonate and sodium dodecylnaphthalene sulfonate; Examples include polyoxyethylene alkyl sulfate salts; polyoxyethylene alkylaryl sulfate salts; dialkyl sulfosuccinates; arylsulfonic acid-formalin condensates; fatty acid salts such as ammonium laurylate and sodium stearate.

Examples of nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid monoglyceride, ethylene oxide and aliphatic Examples include condensates with amines.

Examples of the cationic emulsifier include alkyl ammonium salts such as dodecylammonium chloride.

Examples of the amphoteric emulsifier include betaine ester emulsifiers.

Examples of polymer emulsifiers include poly(meth)acrylates such as sodium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; polyhydroxyalkyl (meth)acrylates such as polyhydroxyethyl acrylate; Examples include polymers having one or more types of monomers as a copolymerization component.

Examples of the reactive emulsifier include emulsifiers having a polymerizable group. Examples of the polymerizable group include polymerizable unsaturated groups such as alkenyl groups (vinyl group, allyl group, etc.), alkenylcarbonyl groups (eg, (meth)acryloyl group, crotonoyl group, etc.). When using a reactive emulsifier as an emulsifier, the water-dispersible resin can contain the reactive emulsifier as a structural unit (repeat unit, etc.).

Specific examples of reactive emulsifiers include propenyl-alkyl sulfosuccinate salts, (meth)acrylic acid polyoxyethylene sulfonate salts, polyoxyethylene alkyl propenyl phenyl ether ammonium sulfate, allyloxymethylalkyloxypolyoxyethylene sulfonate salts, allyl Oxymethylnonylphenoxyethylhydroxypolyoxyethylene sulfonate salt, allyloxymethylalkoxyethylhydroxypolyoxyethylene sulfate salt, bis(polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salt, allyloxymethylalkoxyethylhydroxypolyoxyethylene , polyoxyethylene alkylpropenylphenyl ether, allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene, and the like.

A polymerization initiator can be used when polymerizing the monomer components. As the polymerization initiator, those commonly used in radical polymerization can be used, and among them, water-soluble ones are preferred. For example, persulfates such as potassium persulfate and ammonium persulfate; azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile) ), 2,2'-azobis(2-aminodipropane) hydrochloride, 4,4'-azobis-cyanovaleric acid, 2,2'-azobis(2-methylpropionamidine), 2,2'-azobis Azo compounds such as (2-methylbutanamidoxime) dihydrochloride tetrahydrate; hydrogen peroxide, t-butyl hydroperoxide, benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, ammonium peroxide, etc. peroxides, etc. The polymerization initiators may be used alone or in combination of two or more. The amount of polymerization initiator per 100 parts by mass of monomer components is, for example, 0.01 to 3 parts by mass.

In order to accelerate the decomposition of the polymerization initiator, for example, a decomposing agent for the polymerization initiator such as a reducing agent such as L-ascorbic acid, sodium thiosulfate, or sodium bisulfite, or a transition metal salt such as ferrous sulfate is added to the reaction system. It may be added in an appropriate amount. Furthermore, additives such as a chain transfer agent, a pH buffering agent, a chelating agent, and the like may be added in appropriate amounts into the reaction system, if necessary. Examples of chain transfer agents include alkyl mercaptans, aromatic mercaptans, halogenated hydrocarbons, etc. Among these, lauryl mercaptan, n-butyl mercaptan, t-butyl mercaptan, octyl mercaptan, n-dodecyl Mercaptan, 2-ethylhexyl thioglycolate, 2-methyl-t-butylthiophenol, carbon tetrabromide, α-methylstyrene dimer, and the like are preferred.

The atmosphere during emulsion polymerization of the monomer components is not particularly limited, but is preferably an inert gas such as nitrogen gas. The polymerization temperature during emulsion polymerization of the monomer components is not particularly limited, but is usually preferably 50 to 100°C. The polymerization temperature may be constant or may be changed during the polymerization reaction. The polymerization time for emulsion polymerization of the monomer components is not particularly limited and may be appropriately set depending on the progress of the polymerization reaction, but is usually about 2 to 9 hours.

Functional layer 1 may contain a surfactant. From the viewpoint of stably dispersing the particles A and B in the coating composition used for forming the functional layer 1, it is preferable to use a surfactant. Surfactants are classified into anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc., and any of them may be used. The surfactants may be used alone or in combination of two or more.

Functional layer 1 contains, as other components, pigments (excluding those corresponding to particles A or particles B), dispersants, antioxidants, antisettling agents, surface conditioners, viscosity conditioners, antifoaming agents, Requires silane coupling agents, adhesion improvers, algaecides, antifungal agents, preservatives, insecticides, antibacterial agents, antiviral agents, ultraviolet absorbers, radical scavengers, antistatic agents, conductivity imparting agents, etc. It may be included as appropriate. Note that details of the adhesion improver will be described later.

The visible light transmittance of the functional layer 1 is preferably 60% or more, more preferably 65% or more, particularly preferably 75% or more.

In this specification, visible light transmittance means total light transmittance in the visible region (360 nm to 750 nm), and is determined by measurement based on JIS K 7361-1:1997.

In the coated body of the present invention, the functional layer preferably includes the above-described functional layer 1 and a functional layer laminated on the functional layer 1 and containing a water repellent. By laminating a functional layer containing a water repellent on the functional layer 1, the water repellency of the functional layer can be further improved. In this specification, the functional layer containing this water repellent is also referred to as "functional layer 2."

The average thickness of the functional layer 2 is preferably 10 μm or less, more preferably 0.1 to 5 μm, and even more preferably within the range of 0.5 to 5 μm. By forming the functional layer 2 with a thickness of 0.1 μm or more, high water repellency can be stably achieved. On the other hand, if the functional layer 2 is too thick, it may become difficult to form irregularities on the surface of the coated body. Moreover, when producing a thick functional layer, coating unevenness tends to occur, which may make it difficult to exhibit stable functionality.

As the water repellent, for example, a silicone water repellent can be used, and it is particularly preferable to use an alkoxysilane water repellent having a structure having an alkoxyl group. When the water repellent is used in the form of monomers or oligomers, it exists in the functional layer 2 as a hydrolyzed condensate thereof.

Examples of the alkoxysilane water repellent include those having a medium-chain or long-chain alkyl group as a functional group, such as those shown in the following general formula (4) or the following general formula (5). can be mentioned.

General formula (4): R _n Si(OR ¹ ) _4-n
In the general formula (4), n represents an integer of 1 to 3, R represents a medium-chain or long-chain alkyl group, and R ¹ represents an alkyl group.

General formula (5): R _n Si(OR ¹ ) _4-n-m X _m
In the general formula (5), n represents an integer of 1 to 3, m represents an integer of 0 to 2, R represents a medium chain or long chain alkyl group, R ¹ represents an alkyl group, and X represents an integer of 0 to 2. Indicates a hydrolyzable group.

Such alkoxysilane water repellent agents may be made of monomer molecules, or may be made of oligomers in which multiple molecules are polycondensed by hydrolysis.

In general formulas (4) and (5), suitable examples of the medium-chain or long-chain alkyl group (R) include straight-chain or branched-chain alkyl groups having 4 to 12 carbon atoms. Further, the alkyl group (R ¹ ) constituting the alkoxy group (OR ¹ ) is usually preferably a lower alkyl group having about 1 to 3 carbon atoms. Further, examples of the hydrolyzable group include an alkoxy group, an ester group, and a halogen atom.

In addition, the functional alkyl group of the alkoxysilane water repellent is preferably a medium-chain or long-chain alkyl group with 4 to 12 carbon atoms, and in the case of a lower alkyl group with 1 to 3 carbon atoms, it has a good It becomes difficult to obtain a water repellent effect, and the same is true when the number of carbon atoms exceeds 12.

The water repellent is preferably used in the form of an oil (monomer or oligomer) or in the form of an emulsion that has been previously dispersed in water. Moreover, when using a silicone water repellent, it is also preferable to contain silica fine particles.

Further, as the water repellent, in addition to the above-mentioned silicone water repellent, known water repellents such as a fluorine water repellent and a fluorine-containing silicone water repellent can be used. Examples of the fluorine-based water repellent include fluorine-containing acrylate polymers and perfluoropolyethers. Examples of fluorine-containing silicone water repellents include those in which a fluorine atom-containing organic group is introduced into the above-mentioned silicone water repellent, and an organic group containing a silicon atom at the terminal or side chain of perfluoropolyether. Examples include those into which a group has been introduced.

The amount of water repellent in the functional layer 2 is preferably 30% by mass or more, more preferably 50% by mass or more. Water repellents may be used alone or in combination of two or more.

In the coated body of the present invention, it is preferable that functional layer 1 and/or functional layer 2 contain an adhesion improver. Here, the adhesion improver is a substance used to improve the adhesion of the water repellent in the functional layer 2 and to prevent the water repellent from falling off. By using the adhesion improver in one or both of the functional layer 1 and the functional layer 2, it is possible to obtain the effect of preventing the water repellent from falling off. As the adhesion improver, substances known as silane coupling agents and crosslinking agents can be suitably used. The adhesion improvers may be used alone or in combination of two or more.

Examples of crosslinking agents include melamine crosslinking agents, oxazoline crosslinking agents, acrylamide crosslinking agents, polyamide crosslinking agents, epoxy crosslinking agents, isocyanate crosslinking agents, aziridine crosslinking agents, titanate crosslinking agents, and urea crosslinking agents. Examples thereof include alkyl alcoholized urea crosslinking agents, hydrazide crosslinking agents, carbodiimide crosslinking agents, and polyvalent metal compounds such as zirconium compounds, zinc compounds, titanium compounds, and aluminum compounds.

Examples of oxazoline crosslinking agents include 2,2'-bis(2-oxazoline), 1,2-bis(2-oxazolin-2-yl)ethane, 1,4-bis(2-oxazolin-2-yl) ) butane, 1,8-bis(2-oxazolin-2-yl)butane, 1,4-bis(2-oxazolin-2-yl)cyclohexane, 1,2-bis(2-oxazolin-2-yl)benzene , 1,3-bis(2-oxazolin-2-yl)benzene, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2 -isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, etc.

Examples of carbodiimide crosslinking agents include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-[3-(dimethylamino)propyl ]-N'-ethylcarbodiimide, N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide methiodide, N-tert-butyl-N'-ethylcarbodiimide, N-cyclohexyl-N'-(2 -morpholinoethyl)carbodiimide Carbodiimide compounds such as meso-p-toluenesulfonate, N,N'-di-tert-butylcarbodiimide, N,N'-di-p-tolylcarbodiimide; Examples include carbodiimide compounds obtained by known condensation reactions; carbodiimide compounds made from polyisocyanates and polyalkylene oxides, and the like.

Examples of the silane coupling agent include an amino group-containing silane coupling agent, an epoxy group-containing silane coupling agent, an isocyanate group-containing silane coupling agent, and the like.

Specific examples of amino group-containing silane coupling agents include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropylmethyldimethoxysilane, and γ-aminopropyl. Methyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ- Aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriisopropoxysilane, N-phenyl-γ-aminopropyl Trimethoxysilane, γ-ureidopropyltrimethoxysilane, γ-anilinopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-vinylbenzyl-γ-aminopropyl Examples include triethoxysilane, N-β-(aminoethyl)-8-aminooctyltrimethoxysilane, and γ-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine.

Specific examples of epoxy group-containing silane coupling agents include glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, γ - Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyl(ethyl)dimethoxysilane, β-3,4-epoxycyclohexylethyltrimethoxysilane, β-3,4-epoxycyclohexylethyltriethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 8- Examples include glycidoxyoctylmethyldimethoxysilane and 8-glycidoxyoctylmethyldiethoxysilane.

Specific examples of the isocyanate group-containing silane coupling agent include 3-isocyanatepropyltriethoxysilane.

The amount of adhesion improver in functional layer 1 is preferably from 0.3 to 30% by weight, more preferably from 0.5 to 20% by weight. The amount of adhesion improver in the functional layer 2 is preferably 1 to 30% by weight, more preferably 5 to 20% by weight. One type of adhesion improver may be used, or two or more types may be used in combination.

Functional layer 2 contains resin, pigment, dispersant, antioxidant, antisettling agent, viscosity modifier, surface modifier, antifoaming agent, algae preventive agent, fungicide, preservative, and insecticide as other components. , an antibacterial agent, an antiviral agent, an ultraviolet absorber, a radical scavenger, an antistatic agent, a conductivity imparting agent, etc. may be included as appropriate.

The visible light transmittance of the functional layer 2 is preferably 75% or more, more preferably 80% or more, particularly preferably 90% or more.

In the coated body of the present invention, the water contact angle on the surface of the functional layer is preferably within the range of 100° to 170°, more preferably within the range of 110° to 165°, and more preferably 120° to 160°. More preferably, it is within the range of . The water contact angle is a measure of wettability with water, and generally, the higher the water contact angle, the higher the water repellency. The surface of the functional layer here refers to the surface of the entire functional layer. For example, when the functional layer consists of functional layer 1, the water contact angle on the surface of the functional layer is the water contact angle on the surface of functional layer 1, and when the functional layer consists of multiple layers, the multiple layers are laminated. This is the water contact angle on the outermost surface of the functional layer. The water contact angle can be increased by increasing the actual surface area by creating a fractal structure or double structure on the surface, by increasing the hydrophobicity of particles B and binder resin, or by increasing the amount of components with low surface tension. As a result, a highly water-repellent functional layer can be obtained.

In this specification, the water contact angle of the functional layer refers to the water contact angle determined by the sessile drop method. Specifically, 10 μL of distilled water was dropped on the surface of the functional layer, left to stand for 10 seconds in an atmosphere of 20°C, and then measured using a general contact angle meter (for example, Kyowa Interface Science Co., Ltd. CA-X contact angle measurement device). can be used to measure the contact angle of water.

In the coated body of the present invention, the visible light transmittance of the functional layer is preferably 60% or more, more preferably 65% or more, particularly preferably 75% or more. The functional layer here refers to the entire functional layer. For example, when the functional layer consists of functional layer 1, the visible light transmittance of the functional layer is the visible light transmittance of functional layer 1, and when the functional layer consists of multiple layers, the functional layer is formed by laminating multiple layers. visible light transmittance.

In the coated body of the present invention, the functional layer, particularly the functional layer 1, may be formed on the coating layer. Here, the coating layer may be one layer or multiple layers, and is coated for various purposes. For example, when a design is to be applied to a base material, a design layer can be applied, and when the surface of the base material is to be protected, a protective layer can be applied. If you want to take advantage of the design of the base material, prevent it from being sucked into the base material, and improve the adhesion of the functional layer, you can apply an undercoat layer on the base material. Further, the coating layer may be composed of a plurality of coating layers for different purposes, and for example, a design layer and a protective layer may be laminated.

The coating layer, particularly the coating layer in contact with the functional layer 1, preferably contains particles C having an average particle diameter of 30 to 100 μm. In this way, by using particles with a large average particle size, preferably particles with an average particle size larger than particle B, in the coating layer located below the functional layer, the water repellency of the coated body can be further improved. Can be done.

The average thickness of the coating layer containing particles C is preferably 10 to 100 μm, more preferably 12 to 80 μm, and even more preferably 15 to 50 μm.

Particles C are particles on the micron order, and have an average particle diameter of 30 to 100 μm, preferably 30 to 80 μm, and more preferably 35 to 60 μm. The average particle diameter of particles C refers to the particle diameter measured with a transmission electron mirror, a scanning electron mirror, or an optical microscope, and can be determined as described for the average particle diameter of particles A and B.

In the coating layer containing particles C, the amount of particles C in the coating layer is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. Particles C may be used alone or in combination of two or more types.

Particles C, like particles A and B, can be any of inorganic particles, organic particles, and organic-inorganic composite particles, and may be porous particles. Particles C are preferably resin beads, silica or glass beads, and more preferably resin beads.

The coating layer usually contains resin. The amount of resin in the coating layer (in each coating layer if there are multiple layers) is preferably 30 to 99% by mass, more preferably 50 to 95% by mass. The resins may be used alone or in combination of two or more.

The coating layer contains pigments, dispersants, antioxidants, antisettling agents, antifoaming agents, silane coupling agents, adhesion agents, algaecides, fungicides, preservatives, and insecticides as other ingredients. , an antibacterial agent, an antiviral agent, an ultraviolet absorber, a radical scavenger, an antistatic agent, a conductivity imparting agent, and the like may be included as appropriate.

In the coated body of the present invention, examples of the base material include epoxy resin, ABS resin, polycarbonate, polyvinyl chloride, polystyrene, acrylic resin, particularly polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polypropylene (PP). ), metal base materials such as iron, stainless steel, aluminum, copper, titanium, and their alloys, metals such as cement, concrete, plaster, calcium silicate, calcium carbonate, marble, artificial marble, glass, ceramic, etc. Other examples include inorganic base materials, wood base materials, and composite base materials that combine two or more of these base materials.

The base material has various shapes, for example, a plate-shaped base material. The surface of the base material may be smooth or may have unevenness.

The coated body of the present invention is preferably a building material, particularly a building board. Specific examples of building materials include wood building materials such as veneer, plywood, particle board, and medium density fiberboard (MDF); ceramic siding boards, flexible boards, calcium silicate boards, gypsum slag barlite boards, and wood chips. Ceramic building materials such as cement boards, asbestos cement boards, pulp cement boards, precast concrete boards, lightweight aerated concrete (ALC) boards or ALC panels, and gypsum boards; various building materials such as metal siding boards, metal building materials such as aluminum, iron, and stainless steel; (In particular, building boards) are preferred. Further, specific examples of the base material include plastic base materials such as a vinyl chloride sheet, tarpaulin, plastic cardboard (plastic cardboard), and acrylic board, tiles, and glass plates.

The surface of the base material may be subjected to pretreatment such as degreasing treatment, chemical conversion treatment, polishing, etc., or coating with a sealer or primer. For example, if the base material is a ceramic building material or other base material (especially a porous base material) that may absorb excessive coating material, the surface of the base material is coated with a sealer, and a sealer layer is placed on the base material. may be formed. Further, when the base material is a metal building material or the like, the surface of the base material may be coated with a primer, and a primer layer may be formed on the base material.

The coated body of the present invention can be suitably applied to external walls, roofs, fences, bridges, steel towers, elevated structures, oil tanks, vehicles, construction machinery, signboards, interior materials, etc.

The coating material (paint, etc.) for forming the functional layer (particularly functional layer 1 and functional layer 2) and the coating layer can be prepared by mixing various components that are appropriately selected as necessary. The coating material may be a one-component type or a two-component type, but in the case of a two-component type coating material, it can be prepared by preparing a base agent and a curing agent in advance and mixing them at the time of coating. Usually, the base material contains a resin, and the curing agent contains a crosslinking agent. When mixing the base resin and the curing agent, additives such as water and a diluent may be further added for the purpose of adjusting viscosity and the like.

The coating method for the coating material is not particularly limited, and may be any known coating method such as brush coating, roller coating, trowel coating, spatula coating, flow coater coating, spray coating (e.g. air spray coating, airless spray coating), shower coater. Painting, dipping painting, etc. can be used.

The means for drying the coating material is not particularly limited, and may be either natural drying at ambient temperature or forced drying using a dryer or the like. Also, baking may be performed. In the case of baking, the heating temperature is appropriately set depending on the base material and coating material, but it is usually preferable to form a film by heating within the range of 40 to 180°C.

When the functional layer of the coated body of the present invention includes the functional layer 1 and the functional layer 2, it is preferable that the functional layer 1 and the functional layer 2 are coated wet-on-wet. Wet-on-wet coating improves interlayer adhesion between functional layer 1 and functional layer 2, leading to improved sustainability of water repellency.

Another embodiment of the present invention is a coating composition containing particles A having an average particle diameter of 5 nm to 500 nm, particles B having an average particle diameter of 1 μm to 30 μm, and a binder component. In this specification, this coating composition is also referred to as "the coating composition of the present invention." The coating composition of the present invention is a coating composition in which the amount of the binder component in the coating film forming components is within the range of 5 to 50% by mass, and can be used to form the above-mentioned functional layer 1.

The coating composition of the present invention contains particles A having an average particle diameter of 5 nm to 500 nm. Regarding the explanation of "particles A" that can be used in the coating composition of the present invention, unless otherwise specified, the explanation of "particles A" for the functional layer 1 of the coated body of the present invention described above applies similarly.

For example, in the coating composition of the present invention, the average particle diameter of particles A is preferably 10 nm to 200 nm, more preferably 20 nm to 120 nm, and even more preferably 30 to 80 nm. Further, the particles A are preferably metal oxide particles, and more preferably hydrophilic silica.

On the other hand, regarding the amount of particles A in the coating composition of the present invention, since the coating composition of the present invention may contain volatile substances such as solvents, there are some differences from the above description of the coated body of the present invention. .

The amount of particles A in the coating composition of the present invention is preferably 1 to 40 mass, and preferably 3 to 30 mass, from the viewpoint of adjusting the amount of particles A in functional layer 1 within the range specified above. It is even more preferable.

The coating composition of the present invention contains particles B having an average particle diameter of 1 μm to 30 μm. Regarding the explanation of "particles B" that can be used in the coating composition of the present invention, unless otherwise specified, the explanation of "particles B" for the functional layer 1 of the coated body of the present invention described above applies similarly.

For example, in the coating composition of the present invention, the average particle diameter of particles B is preferably 2 μm to 30 μm, more preferably 5 μm to 20 μm, and most preferably 5 μm to 10 μm. Further, the particles B are preferably resin beads or glass beads, and more preferably resin beads.

On the other hand, regarding the amount of particles B in the coating composition of the present invention, since the coating composition of the present invention may contain volatile substances such as solvents, there are some differences from the above description of the coated body of the present invention. .

The amount of particles B in the coating composition of the present invention is preferably 1 to 30 mass, and preferably 2 to 20 mass, from the viewpoint of adjusting the amount of particles B in functional layer 1 within the range specified above. It is even more preferable.

Furthermore, in the coating composition of the present invention, the ratio of particles A to particles B, that is, the ratio of particles A to particles B, is preferably within the range of 40:60 to 95:5, and preferably 50:50. More preferably, the ratio is within the range of 85:15.

The coating composition of the present invention contains a binder component. Regarding the explanation of the "binder component" that can be used in the coating composition of the present invention, unless otherwise specified, the explanation of the "binder component" for the functional layer 1 of the coated body of the present invention described above applies similarly.

For example, in the coating composition of the present invention, the binder component has the formula (1): R1 _n Si(OR2) _4-n (wherein R1 is an organic group having 1 to 8 carbon atoms, and R2 is an organic group having 1 to 8 carbon atoms). -5 alkyl group, and n is 1 or 2) as a constituent unit (repeat unit, etc.). Further, the binder component more preferably contains an organic-inorganic composite resin, and even more preferably contains an organic-inorganic composite resin containing the compound represented by formula (1) and/or its partially hydrolyzed condensate as a constituent unit. .

On the other hand, the amount of the binder component in the coating composition of the present invention may differ from the above description of the coated body of the present invention because the coating composition of the present invention may contain volatile substances such as solvents. .

In the coating composition of the present invention, the amount of the binder component in the coating film forming components is within the range of 5 to 50% by mass, preferably within the range of 10 to 40% by mass, and 15 to 35% by mass. More preferably, it is within the range of .

In this specification, a coating film-forming component refers to a component excluding volatile components such as water and an organic solvent, and is a component that will ultimately form a coating film. In this specification, the components remaining when the coating composition is dried at 130° C. for 10 minutes are treated as coating film-forming components. The amount of the film-forming component in the coating composition of the invention is, for example, 2 to 50% by weight, preferably 5 to 40% by weight, particularly preferably 7 to 30% by weight.

The coating composition of the present invention can include an adhesion promoter. Regarding the explanation of the "adhesion improver" that can be used in the coating composition of the present invention, unless otherwise specified, the explanation of the "adhesion improver" for the functional layer 1 of the coated body of the present invention described above applies similarly. .

On the other hand, the amount of the adhesion improver in the coating composition of the present invention may differ from the above description of the coated body of the present invention because the coating composition of the present invention may contain volatile substances such as solvents. be.

The amount of adhesion promoter in the coating composition of the invention is, for example, in the range from 0.01 to 10% by weight.

The coating composition of the present invention can contain a solvent. As the solvent, water, an organic solvent, or a mixed solvent thereof can be used. Here, the organic solvent is not particularly limited, and various organic solvents such as hydrocarbon solvents, alcohol solvents, ketone solvents, ester solvents, and ether solvents can be used. The organic solvents may be used alone or in combination of two or more. The content of the solvent in the coating composition of the present invention is, for example, 40 to 95% by mass.

Water is not particularly limited, and examples include tap water, as well as pure water such as ion-exchanged water and distilled water. Furthermore, when storing the coating composition for a long period of time, water that has been sterilized by ultraviolet irradiation or the like may be used to prevent the growth of mold and bacteria. The amount of water in the coating composition of the present invention is preferably 40 to 95% by weight. The coating composition of the present invention is preferably a water-based coating composition. In this specification, a water-based coating composition means a coating composition containing water as a main solvent.

Examples of hydrocarbon solvents include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and more specifically, toluene, xylene, solvent naphtha, mineral spirit, hexane, cyclohexane, and octane. , terpene oil, etc. Examples of alcohol solvents include methanol, ethanol, propanol, and butanol; examples of ketone solvents include acetone, methyl ethyl ketone, and methyl isobutyl ketone; and examples of ester solvents include acetic acid. Ethyl, butyl acetate, etc. are mentioned, and examples of the ether solvent include ethylene glycol monoethyl ether, methyl carbitol, etc. Note that solvents having both hydroxyl groups and ether bonds, such as ethylene glycol monoethyl ether and methyl carbitol, are classified as ether solvents in this specification.

The coating composition of the present invention preferably contains water as a solvent, and more preferably contains water and a hydrophilic organic solvent. As used herein, the term "hydrophilic organic solvent" refers to an organic solvent that can be homogeneously mixed with water in a coating composition at 25°C. As the hydrophilic organic solvent, alcohol-based solvents or ether-based solvents are preferred. The amount of hydrophilic organic solvent in the coating composition of the present invention is preferably 0 to 30% by weight.

The coating composition of the present invention preferably contains a surfactant. Surfactants are classified into anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc., and any of them may be used. The surfactants may be used alone or in combination of two or more. The amount of surfactant in the coating composition of the invention is, for example, 0.01 to 5% by weight.

The coating composition of the present invention preferably contains water, a hydrophilic organic solvent, and/or a surfactant. By using a hydrophilic organic solvent and a surfactant in combination, particles A and particles B can be stably dispersed in a coating composition containing water as a solvent.

The coating composition of the present invention includes, as other components, pigments (excluding those corresponding to particles A or particles B), dispersants, antifoaming agents, antioxidants, antisettling agents, silane coupling agents, It may contain an algaecide, a fungicide, a preservative, an insecticide, an antibacterial agent, an antiviral agent, an ultraviolet absorber, a radical scavenger, an antistatic agent, a conductivity imparting agent, etc., as necessary.

The coating composition of the present invention can be prepared by mixing appropriately selected various components as necessary. The coating composition of the present invention may be of a one-component type or a multi-component type, but in the case of a multi-component coating composition, the main ingredient and other components such as a curing agent and additives are prepared in advance, It can be prepared by mixing these at the time of painting. Usually, the base material contains a resin, and the curing agent contains a crosslinking agent. When mixing the base resin and the curing agent, additives such as water and a diluent may be further added for the purpose of adjusting viscosity and the like.

The coating method of the coating composition of the present invention is not particularly limited, and may be any known coating method such as brush coating, roller coating, trowel coating, spatula coating, flow coater coating, spray coating (e.g. air spray coating, airless spray coating). ), shower coater painting, dipping painting, etc. can be used.

The means for drying the coating composition of the present invention is not particularly limited, and may be either natural drying at ambient temperature or forced drying using a dryer or the like. Also, baking may be performed. In the case of baking, the heating temperature is appropriately set depending on the substrate and the coating composition, but it is usually preferable to form a film by heating within the range of 40 to 180°C.

The coating composition of the present invention is preferably a clear coating. In this specification, the clear paint refers to a clear paint that has a visible light transmittance of 60% or more when a film with a thickness of 10 μm is formed, and the light transmittance is preferably 65% or more, and 75% or more. % or more is particularly preferable.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to the Examples below.

<Preparation of silyl group-containing vinyl resin solution>
100 parts by mass of ethylene glycol monobutyl ether was added to a reactor equipped with a reflux condenser and a stirrer, and the mixture was heated to 100° C. with stirring. Next, 50 parts by mass of isobutyl methacrylate, 31.5 parts by mass of 2-ethylhexyl methacrylate, 10 parts by mass of γ-methacryloxypropyltrimethoxysilane, 8.5 parts by mass of acrylic acid, and t-butylperoxy-2-ethylhexano A mixed solution of 2.5 parts by mass of ate was added dropwise at 100°C over 3 hours, and then the temperature was raised to 105°C and maintained for 2 hours to complete the reaction, yielding a silyl group-containing vinyl resin solution a. . The obtained silyl group-containing vinyl resin solution a had a solid content concentration of 50% by mass, an acid value of 65 mgKOH/g, and a number average molecular weight of 10,000.

<Preparation of organic-inorganic composite resin aqueous dispersion 1>
In a reactor equipped with a reflux condenser and a stirrer, (a) 23 parts by mass of a partially hydrolyzed condensate of methyltrimethoxysilane (SR2402 manufactured by Dow Corning Toray Industries, Inc.; solid content 100% by mass), methyltrimethoxy After adding and mixing 8 parts by mass of silane, 1.7 parts by mass of dimethyldimethoxysilane, 25 parts by mass of (b) silyl group-containing vinyl resin solution a, and 10 parts by mass of isopropanol, 3.0 parts by mass of ion-exchanged water and 1N 0.05 parts by mass of hydrochloric acid was added, and the mixture was reacted at 60° C. for 3 hours. Next, 0.3 parts by mass of monoacetylacetonate bis(ethyl acetoacetate)aluminum and 0.8 parts by mass of ion-exchanged water were added, and the mixture was further reacted at 60° C. for 3 hours. Next, 0.6 parts by mass of triethylamine and 37 parts by mass of water were added, and after stirring at 50°C for 1 hour, the solvent was removed under reduced pressure (1.3 × 10 ⁴ Pa (100 torr)), and the mixture was diluted with water. Dilution was adjusted so that the solid content concentration was 35% by mass to obtain an aqueous dispersion 1 of an organic-inorganic composite resin containing the compound represented by formula (1) as a constituent unit.

<Preparation of organic-inorganic composite resin aqueous dispersion 2>
A reactor equipped with a cooler and a stirrer was charged with 20 parts by mass of ion-exchanged water and 0.2 parts by mass of an ether sulfate emulsifier (trade name "ADEKA Soap SR1025", manufactured by ADEKA Co., Ltd.) as an emulsifier. The temperature was raised to 75° C. while purging the inside with nitrogen. Next, 0.5 parts by mass of potassium persulfate (polymerization initiator) was added, and an emulsion prepared by stirring and mixing in a separate container (methyl methacrylate: 20 parts by mass, butyl acrylate: 12 parts by mass, cyclohexyl acrylate) was added. : 15 parts by mass, acrylic acid: 1 part by mass, γ-methacryloxypropyltrimethoxysilane: 2 parts by mass, Adekariasoap SR1025: 2 parts by mass, ion-exchanged water: 23 parts by mass) were added dropwise over 3 hours. Thereafter, the organic-inorganic composite resin containing the compound represented by formula (1) as a constituent unit was aged at 80°C for 2 hours with continuous stirring, cooled to 40°C, and adjusted to pH 8.0 by adding ammonia water. Aqueous dispersion 2 (solid content concentration 45% by mass) was obtained.

<Preparation of acrylic resin aqueous dispersion>
A reactor equipped with a cooler and a stirrer was charged with 20 parts by mass of ion-exchanged water and 0.2 parts by mass of an ether sulfate emulsifier (trade name "ADEKA Soap SR1025", manufactured by ADEKA Co., Ltd.) as an emulsifier. The temperature was raised to 75° C. while purging the inside with nitrogen. Next, 0.5 parts by mass of potassium persulfate (polymerization initiator) was added, and an emulsion (methyl methacrylate: 21 parts by mass, butyl acrylate: 13 parts by mass, cyclohexyl acrylate) was mixed with stirring in a separate container. 15 parts by mass of acrylic acid, 2 parts by mass of Adekaria Soap SR1025, and 23 parts by mass of ion-exchanged water) were added dropwise over 3 hours. Thereafter, the mixture was aged at 80° C. for 2 hours while stirring, and after cooling to 40° C., ammonia water was added to adjust the pH to 8.0 to obtain an aqueous acrylic resin dispersion with a solid content concentration of 45%.

<Preparation of clear paint composition>
Clear paints 1 to 3 were prepared according to the formulations shown in Table 1. The amounts of each component of the formulations shown in the table are given in parts by weight. The ingredients blended are as follows.
・Polydulex G613 [Water-dispersible resin, product name manufactured by Asahi Kasei Chemicals]
・Viscalex VG2 [Thickener, trade name manufactured by Hoechst Synthesis Co., Ltd.]
・BYK-028 [Defoaming agent, product name manufactured by BYK Chemie Japan Co., Ltd.]
・BYK-349 [Leveling agent, product name manufactured by BYK Chemie Japan Co., Ltd.]
・TINUVIN 1130 [UV absorber, product name manufactured by BASF Japan Ltd.]
・TINUVIN 292 [Light stabilizer, product name manufactured by BASF Japan Ltd.]
・Diethylene glycol monobutyl ether [film-forming aid]
・Toughtic AR650M [transparent resin beads, average particle size 30 μm, product name manufactured by Toyobo Co., Ltd.]
・Toughtic AR650ML [transparent resin beads, average particle size 80 μm, product name manufactured by Toyobo Co., Ltd.]

<Preparation of paint for forming functional layer 1>
Paints for forming functional layer 1 were prepared according to the formulations shown in Tables 2 to 8. The amounts of each component of the formulations shown in the table are given in parts by weight. The ingredients blended are as follows.
Hydrophilic silica 1: Snowtex 30, hydrophilic silica, average particle size 12 nm, nonvolatile content 30% by mass, manufactured by Nissan Chemical Co., Ltd. Hydrophilic silica 2: Snowtex 30L, hydrophilic silica, average particle size 45 nm, nonvolatile content 30 Mass%, product manufactured by Nissan Chemical Co., Ltd. Hydrophilic Silica 3: Snowtex YL, hydrophilic silica, average particle size 60 nm, non-volatile content 40% by mass, product manufactured by Nissan Chemical Co., Ltd. Hydrophilic Silica 4: MP-1040, hydrophilic silica, Average particle diameter 100 nm, nonvolatile content 40% by mass, manufactured by Nissan Chemical Co., Ltd. Hydrophilic Silica 5: MP-4540M, hydrophilic silica, average particle diameter 450 nm, nonvolatile content 40% by mass, manufactured by Nissan Chemical Company Hydrophobic Silica 1: AEROSIL RX200, hydrophobic silica, average particle size 12 nm, manufactured by Evonik Resin beads 1: AR650SX, transparent resin beads, average particle size 5 μm, manufactured by Toyobo Co., Ltd. Resin beads 2: AR650S, transparent resin beads, average particles Diameter 18 μm, manufactured by Toyobo Co., Ltd. Resin beads 3: AR650M, transparent resin beads, average particle size 30 μm, manufactured by Toyobo Co., Ltd. Silica fine particles: ACEMATT TS100, average particle size 10 μm, manufactured by Evonik Adhesion improver 1: KBM403, 3-glycidoxypropyltrimethoxysilane, product manufactured by Shin-Etsu Chemical Co., Ltd. Adhesion improver 2: KBM603, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, product manufactured by Shin-Etsu Chemical Co., Ltd. Dispersant :QP52000H, hydroxyethylcellulose, Dow Chemical product

<Preparation of paint for forming functional layer 2>
Paints for forming functional layer 2 were prepared according to the formulations shown in Tables 2 to 8. The amounts of each component of the formulations shown in the table are given in parts by weight. The ingredients blended are as follows.
Water repellent 1: Silicone water repellent, DrySeal S, manufactured by DuPont-Toray Specialty Materials Co., Ltd. Adhesion improver 1: KBM403, 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. Adhesion improver 2: KBM603, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, product manufactured by Shin-Etsu Chemical Co., Ltd.

<Preparation of evaluation base material>
The sealer was air-sprayed onto the base material in an amount of 100 g/m ² , and after drying at room temperature for 2 hours, an undercoat was applied on top of it with an amount of 100 g/m ² (dry film thickness: 25 μm). It was air-sprayed and dried at room temperature for one week to prepare a substrate for evaluation. Details of the raw materials used are shown below.
<Base material>
Slate board [150mm x 70mm x 5mm, manufactured by TP Giken Co., Ltd.]
<Sealer>
Water-based Mighty Sealer Multi [Cationic water-based paint, product name manufactured by Dainippon Toyo Co., Ltd.]
<Undercoat paint>
DNT View Acrylic N-40 gray color (used in transparency evaluation test) or white color (used in water contact angle, stain resistance, stain resistance durability evaluation test) [Water-based acrylic emulsion paint, Dainippon Paint Co., Ltd. Co., Ltd. product name]

<Preparation of test plate>
A clear paint was applied by air spray at a concentration of 100 g/m ² and dried at 120° C. for 15 minutes to form a clear layer. Subsequently, a paint for forming functional layer 1 was applied on the clear layer by air spray to form functional layer 1. Except for Example 27, the functional layer 2-forming paint was applied onto the functional layer 1 by air spray to form the functional layer 2. In this way, a test plate having irregularities on the surface was prepared.
The types of clear paint used to form the clear layer of each test plate are shown in Tables 2 to 8. The details of the formulations of the paints for forming functional layer 1 and the paints for forming functional layer 2 used in the preparation of each test plate are shown in Tables 2 to 8. Preparation of Paint for Forming Layer 2> Further, the average thickness of functional layer 1 and the average thickness of functional layer 2 of the test plates produced are shown in Tables 2 to 8.

<Measurement of water contact angle>
Drop 10 μL of distilled water onto the surface of the test plate, let it stand for 10 seconds in an atmosphere of 20°C, and measure the contact angle (static contact angle) using Kyowa Interface Science Co., Ltd. CA-X contact angle measurement device. did. The measured values were evaluated according to the following evaluation criteria. The results are shown in Tables 2-8.
[Evaluation criteria]
◎: Static contact angle is 130 degrees or more and 170 degrees or less.
○: Static contact angle is 115 degrees or more and less than 130 degrees.
Δ: Static contact angle is 100 degrees or more and less than 115 degrees.
×: Static contact angle is less than 100 degrees.

<Transparency test>
The coating film formed on the evaluation substrate (the gray color of DNT View Acrylic N-40 was used as the undercoat) was measured using a tristimulus value direct reading color difference meter "CR400" (trade name, manufactured by Konica Minolta). The transparency of the coating film was evaluated based on the following criteria based on the value of ΔL compared with an unpainted blank standard plate (i.e. evaluation base material). The lower the ΔL value, the better the transparency of the clear layer and functional layer. The results are shown in Tables 2-8.
[Evaluation criteria]
◎:ΔL<2.0
○: 2.0≦ΔL<3.0
△: 3.0≦ΔL<5.0
×: 5.0≦ΔL

<Stain resistance test>
After curing the test board prepared according to the above <Preparation of test board> at room temperature for 10 days, the roof was sloped at 10 degrees with respect to the horizontal plane, and grooves 30 cm long and 3 mm deep were carved at 3 mm pitch. The paint film on the evaluation substrate was mounted vertically on a frame facing south so that rain falling on the roof would run down the surface of the paint film in streaks, and exposed outdoors in that state for one month. The appearance was compared with that of an untested coating film and visually observed using the following criteria. The better the water repellency of the functional layer, the better the stain resistance test results. The results are shown in Tables 2-8.
[Evaluation criteria]
◎: Maintains a clean appearance with no dirt or rain streaks.
○: There is slight dirt, but no rain streaks are observed.
△: There is local dirt and thin rain streaks are observed.
×: There is considerable dirt on the entire surface, and rain streaks are clearly visible.

<Stain resistance durability test>
In the same manner as in the above <Stain Resistance Test>, the cured test plate was mounted on a pedestal, and an exposure test was conducted outdoors for 6 months. Visual observation was made using the following criteria. The better the durability of the water repellency of the functional layer, the better the results of the stain resistance durability test. The results are shown in Tables 2-8.
[Evaluation criteria]
◎: Maintains a clean appearance with no dirt or rain streaks.
○: There is slight dirt, but no rain streaks are observed.
△: There is local dirt and thin rain streaks are observed.
×: There is considerable dirt on the entire surface, and rain streaks are clearly visible.

In the table, "solid content amount of paint forming resin layer 1" indicates the amount of solid content (mass %) in the paint for forming functional layer 1. In this specification, the amount of solid content in a paint can be translated into the amount of film-forming components in the paint.
Further, "binder component in functional layer 1" indicates the amount (mass%) of the binder component in functional layer 1, and "particle A in functional layer 1" indicates the amount (% by mass) of particle A in functional layer 1. "Particles B in functional layer 1" indicates the amount (mass%) of particles B in functional layer 1.

Claims (8)

A painted body having a functional layer on the surface, the painted body having unevenness on the surface,
The functional layer comprises a functional layer 1 with an average thickness of 0.01 to 20 μm containing particles A with an average particle size of 5 nm to 500 nm, particles B with an average particle size of 1 μm to 30 μm, and a binder component,
A coated body, characterized in that the amount of the binder component in the functional layer 1 is within the range of 5 to 50% by mass. The coated body according to claim 1, wherein the surface of the functional layer has a water contact angle within a range of 100° to 170°. The coated body according to claim 1 or 2, characterized in that the ratio of the particles A to the particles B in the functional layer 1 is within a range of 40:60 to 95:5 in terms of mass ratio. The coated body according to any one of claims 1 to 3, wherein the binder component contains a compound represented by formula (1) as a constitutional unit.
Formula (1): R1 _n Si(OR2) _4-n
(In the formula, R1 is an organic group having 1 to 8 carbon atoms, R2 is an alkyl group having 1 to 5 carbon atoms, and n is 1 or 2.) The coated body according to any one of claims 1 to 4, wherein the functional layer further comprises a functional layer 2 containing a water repellent agent laminated on the functional layer 1. The coated body according to claim 5, characterized in that the functional layer 1 and/or the functional layer 2 contains an adhesion promoter. The coated body according to any one of claims 1 to 6, wherein the particles A are hydrophilic silica. Contains particles A with an average particle diameter of 5 nm to 500 nm, particles B with an average particle diameter of 1 μm to 30 μm, and a binder component, and the amount of the binder component in the coating film forming components is within the range of 5 to 50% by mass. A paint composition characterized by: