JP2018109108A - Coating composition, coating film and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition that can form a coating film having liquid repellency and powder adhesion resistance, and provide a coating film having liquid repellency and powder adhesion resistance.SOLUTION: A coating composition contains (A) trialkoxyalkylsilane represented by general formula (RO)SiR(where Rindependently represents a C1-4 alkyl group, Ris a C6-16 alkyl group), (B) tetraalkoxysilane represented by general formula (RO)Si (where Rindependently represents a C1-4 alkyl group), (C) an inorganic nanoparticle and (D) a catalyst, where a molar ratio between the (B) and (A), (B)/(A), is 0.3-200, and the amount of (C) component is 0.1-20 mass% relative to the total amount of the (A), (B) and (C) components. A coating film is formed from the coating composition.SELECTED DRAWING: None

Description

  The present invention relates to a coating composition, a coating film and an article.

  In buildings and vehicles that are exposed to wind and rain outdoors, a water-repellent coating film may be applied to the base of the object to be protected in order to prevent dirt, corrosion, deterioration, etc. of these buildings and vehicles. .

  For example, in Patent Document 1, organic-inorganic formed on a solid surface is used as a surface modification technique for improving the raindrop removability of glass for automobiles and building materials, ensuring visibility by preventing the appearance of antifogging, and preventing adhesion of dirt. An organic hybrid obtained by co-hydrolysis and polycondensation of an organic silane mixed with a predetermined molar ratio and a metal alkoxide in a solution containing hydrochloric acid as an organic solvent, water and a catalyst. An inorganic transparent hybrid film is proposed.

JP 2013-2131181 A

  In recent years, air pollution by particulates such as PM2.5 has become a serious problem. If it is possible to prevent such powders such as fine particles from adhering to buildings, vehicles, clothes, etc., it is considered that dirt and health damage due to the adhesion of powders can be reduced.

  However, in Patent Document 1, raindrop removability is improved by reducing the difference between the advancing contact angle and the receding contact angle with respect to a liquid whose surface tension is in a specific range, and what is actually measured and evaluated is as follows. , Water / oil repellency, fingerprint resistance and antifogging only ([0014], [0015] and [0111] of Patent Document 1). Therefore, Patent Document 1 does not disclose a technique for preventing adhesion of powder.

  Then, an object of this invention is to provide the coating composition which can form the coating film which has liquid repellency and powder-proof adhesion property.

  Another object of the present invention is to provide a coating film having liquid repellency and powder resistance.

  Another object of the present invention is to provide an article having liquid repellency and powder resistance.

The coating composition according to the present invention comprises:
(A) Trialkoxyalkylsilane represented by the general formula (R ¹ O) ₃ SiR ² (wherein R ¹ is independently an alkyl group having 1 to 4 carbon atoms, and R ² is carbon An alkyl group of 6 to 16),
And (B) the general formula ^(R 3 _O) (wherein, ^{R 3} are each independently an alkyl group having 1 to 4 carbon atoms) tetraalkoxysilane represented by 4 Si,
(C) inorganic nanoparticles,
(D) a catalyst;
Including
The molar ratio (B) / (A) between (B) and (A) is 0.3 to 200,
It is a coating composition whose quantity of (C) with respect to the total amount of said (A), (B) and (C) is 0.1-20 mass%. Thereby, the coating film has liquid repellency and powder resistance.

  The coating film which concerns on this invention is a coating film formed using the said coating composition. Thereby, the coating film has liquid repellency and powder resistance.

  The article according to the present invention is an article having the coating film on its surface. Thus, the article has liquid repellency and powder resistance.

  ADVANTAGE OF THE INVENTION According to this invention, the coating composition which can form the coating film which has liquid repellency and powder-proof adhesion property can be provided. Moreover, according to this invention, the coating film which has liquid repellency and powder-proof adhesion property can be provided. Moreover, according to the present invention, an article having liquid repellency and powder resistance can be provided.

  Hereinafter, embodiments of the present invention will be described. These descriptions are intended to exemplify the present invention and do not limit the present invention in any way.

  In the present specification, wetting of a coating film with a large amount of water is sometimes referred to as submerged water.

  In the present invention, liquid repellency means water repellency and oil repellency.

In the present invention, for R ¹ , R ² and R ³ , these are unsubstituted alkyl groups, which means that the alkyl group has a hetero atom (for example, an oxygen atom, a nitrogen atom, a halogen) and a hetero atom. Means not replaced with.

  In the present invention, the substrate is a surface to which the coating composition is applied, and includes both an unpainted surface and an already-painted surface of an object to be coated.

  In the present invention, two or more embodiments can be arbitrarily combined.

  In the present invention, the paint and the paint composition can be used interchangeably.

In the present specification, (A) a trialkoxyalkylsilane represented by the general formula (R ¹ O) ₃ SiR ² (wherein R ¹ is independently an alkyl group having 1 to 4 carbon atoms, R ² is an alkyl group having 6 to 16 carbon atoms), (B) the general formula ^(R 3 _O) in tetraalkoxysilane represented by 4 Si (wherein, ^{R 3} are each independently, carbon atoms (C) inorganic nanoparticles and (D) catalyst may be referred to as (A) component, (B) component, (C) component and (D) component, respectively.

(Coating composition)
The coating composition according to the present invention comprises:
(A) Trialkoxyalkylsilane represented by the general formula (R ¹ O) ₃ SiR ² (wherein R ¹ is independently an alkyl group having 1 to 4 carbon atoms, and R ² is carbon An alkyl group of 6 to 16),
And (B) the general formula ^(R 3 _O) (wherein, ^{R 3} are each independently an alkyl group having 1 to 4 carbon atoms) tetraalkoxysilane represented by 4 Si,
(C) inorganic nanoparticles,
(D) a catalyst;
Including
The molar ratio (B) / (A) between (B) and (A) is 0.3 to 200,
It is a coating composition whose quantity of (C) with respect to the total amount of said (A), (B) and (C) is 0.1-20 mass%.

  The coating composition according to the present invention includes the components (A) to (D), the component (A) and the component (B) in the above specific molar ratio, and in the above specific ratio (A ) Component, (B) component, and (C) component. Thereby, a coating film having liquid repellency and powder resistance is obtained. Although not wishing to be bound by theory, the following mechanism is presumed as the reason. That is, by including the component (A) and the component (B) in the above specific molar ratio, the silicone coating film has liquid repellency, and the coating film is formed by the inorganic nanoparticles as the component (C). Occasionally, moderately irregularities are formed on the surface of the silicone coating. The unevenness reduces the contact area between the powder and the coating film, and accordingly, the van der Waals force between the powder and the coating film decreases. For this reason, it is estimated that the adhesion of the powder to a coating film reduces.

<(A) component>
The component (A) is a trialkoxyalkylsilane represented by the general formula (R ¹ O) ₃ SiR ² , wherein each R ¹ is independently an alkyl group having 1 to 4 carbon atoms, R ² is an alkyl group having 6 to 16 carbon atoms. (A) A component may be used individually by 1 type or in combination of 2 or more types.

(A) the number of carbon atoms of ^{R 1} in the component of the alkoxy group ^(R 1 O) is 1-4. In one embodiment, R ¹ has 1 to 2 carbons; in another embodiment, R ¹ has ¹ carbon; in another embodiment, R ¹ has 2 carbons is there. In one embodiment, all three alkoxy groups (R ¹ O) in the component (A) are the same. When the carbon number of R ¹ is 5 or more, the liquid repellency of the coating film does not increase.

(A) the number of carbon atoms of component alkyl group ^{(R 2)} is 6-16. R ² preferably has 8 to 14 carbon atoms, and more preferably 10 to 12 carbon atoms. When the carbon number of R ² is 5 or less or 17 or more, the liquid repellency of the coating film does not increase. In one embodiment, the carbon number of R ² is any selected from 6, 8, 10, 12, 14, and 16.

Each of R ¹ and R ^{2 in the} component (A) may be linear or branched, may be substituted, or may be unsubstituted.

  The content of component (A) in the coating composition is the molar ratio of (B) to (A) (B) / (A) (the numerator is the mole of component (B) and the denominator is the mole of component (A). If it is 0.3-200, it will not specifically limit, What is necessary is just to adjust suitably.

  The molar ratio (B) / (A) between (B) and (A) is 0.3 to 200. When the molar ratio is outside this range, the liquid repellency of the coating film does not increase. In one embodiment, the molar ratio (B) / (A) is 0.5 or greater, 1 or greater, 4 or greater, or 40 or greater. In one embodiment, the molar ratio (B) / (A) is 40 or less, 16 or less, or 4 or less. In another embodiment, the molar ratio (B) / (A) is 0.5-40. In yet another embodiment, the molar ratio (B) / (A) is 0.5-16.

<(B) component>
The component (B) is a tetraalkoxysilane represented by the general formula (R ³ O) ₄ Si, and in the formula, each R ³ is independently an alkyl group having 1 to 4 carbon atoms. (B) A component may be used individually by 1 type or in combination of 2 or more types.

The number of carbon atoms in ^{R 3} of the component (B) an alkoxy group ^(R 3 O) is 1-4. In one embodiment, R ³ has 1-2 carbons, in another embodiment, R ³ has 1 carbon, and in another embodiment, R ³ has 2 carbons. is there. In one embodiment, all ^three alkoxy groups (R ³ O) in the component (B) are the same. When the carbon number of R ³ is 5 or more, the liquid repellency of the coating film does not increase.

R ³ of the component (B) may be linear or branched, may be substituted, or may be unsubstituted.

  The content of the component (B) in the coating composition is not particularly limited as long as the molar ratio (B) / (A) between (B) and (A) is 0.3 to 200, and can be adjusted as appropriate. Good.

<(C) component>
(C) A component is an inorganic nanoparticle. Examples of the inorganic nanoparticles include nanoparticles such as silica such as fumed silica, shirasu, quartz glass, aluminum oxide, and titanium oxide.

  The average particle diameter of the inorganic nanoparticles is not particularly limited as long as it is nano-sized, and can be appropriately selected. In one embodiment, 5 to 500 nm. When the average particle diameter is 5 to 500 nm, it is easy to form irregularities with an appropriate size on the surface of the coating film.

Commercially available products may be used as the inorganic nanoparticles. Examples of commercially available products include, for example, hydrophilic fumed silica such as Aerosil (registered trademark) 90, 130, 150, 200, 255, 300, 380, OX50, TT600, 200F, 380F, 200 pharma, and 300 pharma of Evonik Degussa GmbH. Aerosil series; Aerosil (registered trademark) R972, RY50, NY50, RX50, NAX50, RX200, RX300, R504, REA90, NA50Y, RA200HS, etc. Hydrosil fumed silica Aerosil (registered trademark) Alu _{C, Alu 65, Alu 130,} TiO 2 P25, TiO 2 P90, TiO 2 PF 2, TiO 2 T 805, Alu C 805, TiO 2 NKT 90, STX 501, Such as Aero key side series hydrophilic fumed metal oxides such as TX 801 and the like.

  The metal of the inorganic nanoparticles is preferably silicon.

The inorganic nanoparticles are preferably at least one selected from the group consisting of Aerosil (registered trademark) 300, RX300 and Aeroxide (registered trademark) TiO ₂ P90. Thereby, the water resistance of a coating film can be improved.

  The content of the inorganic nanoparticles in the coating composition is such that the amount of (C) is 0.1 to 20% by mass with respect to the total amount of (A), (B) and (C). In one embodiment, the amount of (C) relative to the total amount of (A), (B) and (C) is 0.5% by weight or more, 1% by weight or more, or 5% by weight or more. In one embodiment, the amount of (C) relative to the total amount of (A), (B) and (C) is 10% by weight or less, or 5% by weight or less. In another embodiment, the amount of (C) relative to the total amount of (A), (B) and (C) is 1-5% by weight.

<(D) component>
The component (D) is a catalyst that has a function of promoting the hydrolysis reaction of the alkoxy groups of the components (A) and (B) or promoting the condensation reaction of the components (A) and (B). Examples of such a catalyst include acids, organometallic compounds, metal complexes, bases, amino compounds, and the like. You may use a catalyst individually by 1 type or in combination of 2 or more types.

  Examples of the acid as the component (D) include inorganic acids and organic acids.

  Examples of the inorganic acid of component (D) include sulfuric acid, sulfurous acid, fuming sulfuric acid (oleum), hydrofluoric acid, hydrochloric acid, hydrobromic acid, phosphoric acid, phosphorous acid, diphosphoric acid, nitric acid, hydrogen sulfide, Examples include iodic acid.

  Examples of the organic acid of component (D) include lactic acid, tartaric acid, citric acid, mandelic acid, 2-hydroxyisobutyric acid, quinic acid, malic acid and other 2-hydroxycarboxylic acids, formic acid, acetic acid, and 3-hydroxyisobutyric acid. Monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monofluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzenesulfonic acid, ethylsulfonic acid, methylsulfonic acid, ethylenedisulfonic acid, dodecylsulfonic acid, trifluoromethyl Examples include sulfonic acid, perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acids, maleic acid, picric acid, trihydroxybenzoic acid, trinitrophenol, sulfamic acid, fluorosilicic acid, chlorosulfonic acid, and fluorosulfonic acid.

  (D) When using an inorganic acid or an organic acid as a component, what is necessary is just to adjust content suitably. The density | concentration of an inorganic acid is 0.0001-1 mol / L in one Embodiment, and is 0.001-0.1 mol / L in another embodiment. The concentration of the organic acid is 0.001 to 0.5 mol / L in one embodiment, and 0.05 to 0.5 mol / L in another embodiment.

  The organometallic compound as the component (D) includes, for example, organotin compounds such as dibutyltin diacetate, dibutyltin dioctylate, and dibutyltin dilaurate; aluminum tris (acetylacetone), aluminum tris (acetoacetate ethyl), aluminum diisopropoxy (acetate) Organoaluminum compounds such as acetate ethyl); organics such as zirconium (acetylacetone), zirconium tris (acetylacetone), zirconium tetrakis (ethylene glycol monomethyl ether), zirconium tetrakis (ethylene glycol monoethyl ether), zirconium tetrakis (ethylene glycol monobutyl ether) Zirconium compound; Titanium tetrakis (ethylene glycol monomethyl ether) , Titanium tetrakis (ethylene glycol monoethyl ether), and an organic titanium compound such as titanium tetrakis (ethylene glycol monobutyl ether).

  (D) The metal complex as a component should just have a metal (center metal) and a ligand, and can use a well-known metal complex.

  It does not specifically limit as a metal of a metal complex, It can select suitably and can be used. In one embodiment, the metal of the metal complex is one or more selected from the group consisting of aluminum, titanium, zirconium, chromium, cobalt, iron, manganese, nickel, tin and zinc. In another embodiment, the metal of the metal complex is one or more selected from the group consisting of aluminum, titanium and zirconium.

  It does not specifically limit as a ligand of a metal complex, It can select suitably and can be used. The ligand may be coordinated to a metal (center metal) at one or more atoms in the ligand, may be coordinated as a monodentate ligand, or coordinated as a multidentate ligand. Also good. For example, an acetylacetonato ligand may be enol-type chelate coordinated; may be monodentate coordinated with one oxygen atom; a proton is dissociated from a keto-type methylene group, and a central carbon atom May be coordinated by a σ bond; the carbon of methylene generated by detachment of the proton of the methyl group may be coordinated by a σ bond; or three carbon atoms in the enol form may be coordinated. A combination of these coordinations may be used.

Examples of the ligand of the metal complex include methoxy, ethoxy, n-propoxy (also referred to as n-propyloxy), isopropoxy (also referred to as isopropyloxy), n-butoxy, tert-butoxy, sec-butoxy, n- Linear or branched alkoxides such as octoxy, 2-ethylhexoxy (also called 2-ethylhexyloxy), tert-amyloxy (Ot-C ₅ H ₁₁ ), stearyloxy (OC ₁₈ H ₃₇ ); acetylacetonate (also called ^{_{acetylacetonate, C 5 H 7 O 2 -}} ), ethyl acetoacetate (also referred to as ^{_{ethylacetoacetato, C 6 H 9 O 3 -}} ), isobutyl acetoacetate, 2-ethylhexyl acetoacetate, dodecyl acetoacetate, Oleyl acetoacetate; phosphorus , Dodecylbenzene sulfonic acid, zirconyl chloride, 2-ethyl-3-hydroxy-hexoxyphenyl ^{_{(C 8 H 17 O 2 -}} , also referred to as 2-ethyl-3-oxo-hexyloxy), glycolate, amino ethoxide, methyl Aminoethanolate, ethylaminoethanolate, diethanolamate, triethanolamate, aminoethylaminoethanolate (OC ₂ H ₄ NHC ₂ H ₄ NH ₂ ), lactate ([OCH (CH ₃ ) COOH]), lactate ammonium salt ([OCH (CH ₃ ) COO ⁻ ] NH ₄ ⁺ ), 1,3-propanedioxy (C ₃ H ₆ O ₂ ²⁻ ) and the like.

  In one embodiment, the ligand of the metal complex is a ligand other than an alkoxide, in other words, does not include an alkoxide. In another embodiment, the ligand of the metal complex is a chelating ligand (eg, acetylacetonate and ethylacetoacetate).

  The metal complex may be, for example, a combination of the metal and the ligand, and can be appropriately selected and used.

Further, the metal complex may be an oligomer such as a dimer, trimer, or tetramer. For example, dimers, and titanium butoxide oxide dimer _{((n-C 4 H 9} O) 3 Ti-O-Ti (n-C 4 H 9 O) 3).

  The preparation method of a metal complex is not specifically limited, A well-known method can be used. For example, a metal alkoxide having a central metal is dissolved in a solvent such as 2-propanol, and an acetoacetate ester having a ligand and acetylacetone are added to the solution, followed by heating to reflux. After the reaction, the target metal complex can be obtained by removing the solvent from the solution. More specifically, for example, aluminum monoacetylacetonate bis (2-ethylhexyl acetoacetate) is obtained by adding 2-ethylhexyl acetoacetate to aluminum triisopropoxide and then adding acetylacetone for about 1 hour. Heat to reflux. When 2-propanol is distilled off, aluminum monoacetylacetonate bis (2-ethylhexyl acetoacetate) is obtained.

  A commercially available product may be used as the metal complex. Examples of commercially available products include TA-10, TA-21, TA-23, TA-30, TC-100, TC-401, TC-710, TC-1040, and TC-201 of the ORGATICS series of Matsumoto Fine Chemicals. , TC-750, TC-300, TC-310, TC-315, TC-400, TA-12, TA-60, TA-80, TA-90, TC-120, TC-220, TC-245, TC -730, TC-810, TC-500, TC-510 and other titanium complexes; ZA-45, ZA-65, ZC-150, ZC-540, ZC-700, ZC-580, ZC-126, ZC-300 Zirconium complexes such as: aluminum complexes such as A-1010, A-1001, A-1008, A-1009, and A-1011. In addition, for example, Kawaken Fine Chemical Co., Ltd. trade names such as aluminum ethoxide, AIPD, PADM, AMD, ASBD, ALCH, ALCH-TR, aluminum chelate M, aluminum chelate D, aluminum chelate A (W), algomer, algomer 800AF, Examples include aluminum complexes such as Algomer 1000SF, aluminum sol 10A, aluminum sol F1000, and aluminum sol 10D.

から選択される構造（一般式中、Ｒ^４とＲ^５は、それぞれ、独立して、有機基を表す）を１個以上含む。一実施形態では、Ｒ^４は、水素原子または炭素数１〜１２のアルキル基であり、別の実施形態では、Ｒ^４は、水素原子または炭素数１〜４のアルキル基である。一実施形態では、Ｒ^５は、炭素数１〜３０のアルキル基またはアルケニル基である。別の実施形態では、Ｒ^５は、炭素数１〜５のアルキル基であり、さらに別の実施形態では、Ｒ^５は、炭素数６〜３０のアルキル基またはアルケニル基である。また別の実施形態では、Ｒ^５は、炭素数８〜１８のアルキル基またはアルケニル基である。別の実施形態では、Ｒ^５は、ＣＨ_２ＣＨＣＯＯ（ＣＨ_２）_ｎ−基またはＣＨ_２（ＣＨ_３）ＣＣＯＯ（ＣＨ_２）_ｎ−基である（ｎは、１〜１０の整数）。別の実施形態では、Ｒ^５は、ＣＨ_２ＣＨＣＯＯ（ＣＨ_２）_ｎ−基、ＣＨ_２（ＣＨ_３）ＣＣＯＯ（ＣＨ_２）_ｎ−基、これらの基がそのエチレン性不飽和結合によって重合もしくは共重合した重合体、またはこれらの基と他のエチレン性不飽和結合を有するモノマーとが共重合した重合体である（ｎは、１〜１０の整数）。 In one embodiment, the ligand of the metal complex has the general formula:

1 or more structures (in the general formula, R ⁴ and R ⁵ each independently represents an organic group). In one embodiment, R ⁴ is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and in another embodiment, R ⁴ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In one embodiment, R ⁵ is a C 1-30 alkyl or alkenyl group. In another embodiment, R ⁵ is an alkyl group having 1 to 5 carbon atoms, and in still another embodiment, R ⁵ is an alkyl group or alkenyl group having 6 to 30 carbon atoms. In another embodiment, R ⁵ is an alkyl or alkenyl group having 8 to 18 carbon atoms. In another embodiment, R ⁵ is a CH ₂ CHCOO (CH ₂ ) _n — group or a CH ₂ (CH ₃ ) CCOO (CH ₂ ) _n — group, where n is an integer from 1-10. In another embodiment, R ⁵ is a CH ₂ CHCOO (CH ₂ ) _n — group, a CH ₂ (CH ₃ ) CCOO (CH ₂ ) _n — group, wherein these groups are polymerized or co-polymerized by their ethylenically unsaturated bonds. A polymer obtained by polymerization, or a polymer obtained by copolymerizing these groups and another monomer having an ethylenically unsaturated bond (n is an integer of 1 to 10).

  In one embodiment, the metal complex comprises aluminum bisethyl acetoacetate monoacetylacetonate.

  (D) When using a metal complex as a component, what is necessary is just to adjust suitably content of the metal complex in a coating composition, and it is not specifically limited. In one embodiment, content of the metal complex in a coating composition is 2 mass% or more with respect to the sum total of (A) component, (B) component, and (D) component, and in another embodiment, It is 5 mass% or more. By setting it as 2 mass% or more, there exists an advantage that the water resistance of a coating film increases. In one embodiment, content of the metal complex in a coating composition is 30 mass% or less with respect to the sum total of (A) component, (B) component, and (D) component, and in another embodiment, It is 15 mass% or less. By setting it as 15 mass% or less, there exists an advantage that the transparency of a coating film tends to increase.

  When a metal complex is used as the component (D), in one embodiment, the ratio of the amount (mole) of the component (D) to the total amount (mole) of the alkoxy group of the component (A) and the alkoxy group of the component (B). Is 0.5% or more, and in another embodiment, 1.5% or more. By setting it to 0.5% or more, there is an advantage that the water resistance of the coating film is increased. In one embodiment, the ratio of the amount (mol) of the component (D) to the total amount (mol) of the alkoxy group of the component (A) and the alkoxy group of the component (B) is 5% or less. In the form, it is 3% or less. By setting it to 5% or less, there is an advantage that the transparency of the coating film is easily increased.

  Examples of the base as the component (D) include inorganic bases such as ammonia, sodium hydroxide, and potassium hydroxide; organic bases such as ethylenediamine and alkanolamine.

  Examples of the amino compound as the component (D) include amino-modified silicone, aminosilane, silazane, and amines.

  In one embodiment, the component (D) includes an acid and one or more selected from the group consisting of an organometallic compound and a metal complex. Thereby, water resistance (liquid repellency after immersion) is imparted to the coating film.

  The content of the component (D) in the coating composition may be appropriately adjusted within a range in which the function as a catalyst can be expressed, and is not particularly limited. In one embodiment, it is 0.0001 mol / L or more, 0.001 mol / L or more, or 0.05 mol / L or more, and in another embodiment, 1 mol / L or less, 0.5 mol / L or less, or 0.1 mol / L. L or less.

  In addition to the components (A) to (D), the coating composition according to the present invention includes water; organic solvent; pigment; design material (for example, sand, cinnabar sand, colored sand, beads, colored chips, mineral chips, glass Chips, wood chips and colored beads); film-forming aids; surface conditioners; antiseptics; fungicides; antifoaming agents; light stabilizers; ultraviolet absorbers; antioxidants; Components such as a silane compound other than the components may be contained singly or in combination of two or more.

<Organic solvent>
Examples of the organic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 2-butanol; toluene, hexane, acetylacetone, and butyl acetate other than alcohol. A solvent can be used individually by 1 type or in combination of 2 or more types.

  When the organic solvent is used, the content of the organic solvent in the coating composition may be adjusted as appropriate and is not particularly limited. For example, 0.01 to 20 parts by mass is preferable and 0.1 to 10 parts by mass is more preferable with respect to 1 part by mass in total of the components (A), (B), (C) and (D). .

(Method for preparing coating composition)
The method for preparing the coating composition is not particularly limited, and it may be prepared by mixing the above components (A) to (D) and other components such as water and organic solvent in any order as necessary. it can. The solid content concentration of the coating composition is appropriately adjusted in consideration of workability and the like.

(Coating)
The coating film which concerns on this invention is a coating film formed using the said coating composition. Thereby, the coating film has liquid repellency and powder resistance.

  The thickness of a coating film is not specifically limited, What is necessary is just to adjust suitably according to the average particle diameter of (C) component of a coating composition, etc. The thickness of the coating film may be, for example, 40 to 4000 nm.

(Formation method of coating film)
The method for forming a coating film according to the present invention is not particularly limited, and the coating composition may be applied to an object to be coated (substrate) by a known method, and optionally dried or heated to form a coating film.

  The substrate on which the coating composition is applied is not particularly limited and can be appropriately selected. Examples of objects to be coated include vehicles such as automobiles, trains, buses and taxis; ships; airplanes such as airplanes and helicopters; detached houses, apartment houses such as condominiums, office buildings, public facilities, commercial facilities, Walls, floors, ceilings, roofs, pillars, signboards, electronic signage (digital signage), doors, gates; bridges; vending machines; road signs; traffic lights; Streetlights; LED bulletin boards such as LED systems, liquid crystal systems, and light bulb systems; building materials on construction sites, work machines, building machines; stone monuments; gravestones; clothing; footwear such as shoes; rain gear such as umbrellas; packaging materials; glasses, telescopes, Lenses such as cameras and video cameras; mirrors and the like.

  Examples of the base material include organic or plastic materials such as acrylic resin, methacrylic resin, alkyd resin, phenol resin, epoxy resin, isocyanate resin, melamine resin, silicone resin, polyester resin, polyurethane resin, fluororesin, and rubber; glass Metal such as tin, iron, steel, copper, gold, silver and aluminum; asphalt; ceramic; stone such as concrete, mortar, brick, slate and marble; wood, plywood and the like.

  The substrate may be either an unpainted surface or an already painted surface of an object to be painted. In the case of an already coated surface, the undercoat layer on which the coating composition is coated can be appropriately selected from known coating films. Examples of such a base layer include enamel paint films and clear paint films.

  The method for applying the coating composition on the substrate is not particularly limited, and can be appropriately selected from known methods. Examples of the coating method include dipping, spray coating, curtain coating, brush coating, roll coating, and bar coating.

  The coating amount is not particularly limited, and may be adjusted as appropriate.

  After coating the coating composition on the surface of the substrate or while coating, it is dried at -5 to 100 ° C. with or without heating to form a coating film.

  The drying time is not particularly limited and may be adjusted as appropriate. For example, if the temperature is 23 ° C., it can be dried in about 12 hours to 1 week, and if the temperature is 60 ° C., it can be dried in about 5 minutes to 30 minutes.

  In one embodiment, a method for forming a coating film includes a step of coating a coating composition on a surface of a substrate to form a film, and drying the film with or without heating at −5 to 100 ° C. And a step of forming a coating film, wherein the component (D) of the coating composition includes an acid and one or more selected from the group consisting of an organometallic compound and a metal complex. By using such a component (D), the ratio of Si—OH groups in the coating film to Si—O—Si bonds (Si—OH groups / Si—O—Si bonds) becomes 0.4 or less. Water resistance can be imparted to the coating film. Moreover, the liquid repellency of a coating film can be improved more. The ratio is preferably 0.1 to 0.3.

The ratio of the Si—OH group in the coating film to the Si—O—Si bond (Si—OH group / Si—O—Si bond) is determined by the following method.
-Total reflection method (ATR)
- a peak reflecting the accumulated number 32 times, Si-OH group as 940 cm ^-1, as 1100 cm ^-1 peak reflecting the Si-O-Si bond, determining the ratio of the height of the apex of each peak. If the bands of these peaks partially overlap, the line connecting the ends of each band including the peak is taken as the baseline, a line is drawn from each peak to the baseline, and the length of the line Calculate from the ratio.

  In another embodiment of the method for forming a coating film, a step of coating the above-mentioned coating composition on the surface of the substrate to form a coating film, and heating or not heating the coating film at -5 to 100 ° C And a step of forming a pre-coating film and a step of treating the obtained pre-coating film with a base. By treating with a base, the hydrolysis reaction and condensation reaction of the component (A) and the component (B) in the pre-coating film proceed, and water resistance is imparted to the coating film. Moreover, the liquid repellency of a coating film can be improved more.

  In the step of treating the coating film with a base, examples of the base include ammonia, dimethylamine, trimethylamine, and ethylamine. As a method of treating with a base, for example, a method in which a coating film is left in a sealed space filled with gaseous ammonia; a method in which gaseous ammonia or a basic aqueous solution is sprayed onto the coating film; a base For example, a cloth or paper soaked with an aqueous solution may be attached to the surface of the coating film and allowed to stand.

In one embodiment of the coating film according to the present invention, the dynamic contact angle of the coating film is 10 ° or less. In another embodiment, the dynamic contact angle of the coating is 3-10 °. Here, the dynamic contact angle is A. Hozumi and T. J. et al. It is defined by the difference (θ _A −θ _R ) between the advancing contact angle (θ _A ) and the receding contact angle (θ _R ) described in McCarthy, Langmuir, 26, 2567 (2010). The smaller the dynamic contact angle, the more the droplets on the coating surface slide down the coating surface with a slight inclination angle with respect to the horizontal plane, and the liquid repellency is high.

In one embodiment of the coating film according to the present invention, the composition ratio C / M (the numerator is C and the denominator is M) of carbon C and the main constituent metal element M in the coating film is the coating film surface (depth 0). 10 nm) and a portion other than the coating film surface, and the composition ratio C / M of the coating film surface is 1.5 or more. Thereby, the liquid repellency of a coating film increases more. The main constituent metal element M is, for example, silicon (Si). This composition ratio is calculated | required on condition of the following using X-ray photoelectron spectroscopy analyzer Kratos AXIS Nova (made by Kratos).
Measuring elements: C, Si, O
Step: 0.1 eV
Pass energy: 80
Charge newizer: on

(Goods)
The article according to the present invention is an article having the coating film on the surface. Thus, the article has liquid repellency and powder resistance.

  The article is not particularly limited. For example, an article having a coating film on the ground described in the method for forming a coating film, such as a vehicle such as an automobile, a train, a bus, or a taxi; a ship; an aircraft such as an airplane or a helicopter; Buildings or structures such as houses, office buildings, public facilities, commercial facilities, research facilities, military facilities, tunnels; ceilings, roofs, pillars, signboards, digital signage (digital signage), doors, gates; bridges; vending machines Road sign; Signal; Street light; LED bulletin board such as LED system, liquid crystal system, light bulb system; Building materials, work machines, construction machinery on construction sites; stone monuments; gravestones; clothing; footwear such as shoes; rain gear such as umbrellas; Materials: glasses, telescopes, cameras, video cameras; mirrors; masks.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, these Examples aim at the illustration of this invention, and do not limit this invention at all. Unless otherwise specified, the blending amount means parts by mass.

The details of the materials used in the examples are as follows.
Inorganic nanoparticle 1: Aerosil (registered trademark) 300 of Evonik Degussa GmbH
Inorganic nanoparticles 2: Aeronic (registered trademark) RX300 from Evonik Degussa GmbH
Inorganic nanoparticle 3: Aeroxide (registered trademark) TiO ₂ P90 manufactured by Evonik Degussa GmbH
Catalyst 1 HCl: 0.01M Hydrochloric acid catalyst 2 Aluminum chelate D: Aluminum bisethyl acetoacetate monoacetylacetonate (metal complex), manufactured by Kawaken Fine Chemical Co., Ltd., trade name: Aluminum chelate D, solid content: 75%
Catalyst 3 Citric acid: Trade name C1949 manufactured by Tokyo Chemical Industry Co., Ltd.
Catalyst 4 TC-120: Titanium acetylacetonate (metal complex), manufactured by Matsumoto Fine Chemical Co., Ltd., trade name ORGATICS TC-120, solid content 53%
Catalyst 5 Mandelic acid: trade name S14-75781 manufactured by Wako Pure Chemical Industries, Ltd.
Solvent 1: Ethanol, Wako Pure Chemical Industries, reagent special grade solvent 2: Isopropanol, Wako Pure Chemical Industries, reagent special grade coating: Aluminum plate (trade name A1100P, manufactured by Nippon Test Panel Co.) Sliding test oil: manufactured by Nikko Casty Co., Ltd., anti-rust oil, trade name CASTY space coat S-100
Powder for powder adhesion test: Trade name SPF-130MC (white pigment) manufactured by Denka

(Examples 1 to 29 and Comparative Examples 1 to 10)
Using the components (A) and (B) shown in Table 1, coating compositions of Examples and Comparative Examples were prepared with the formulations shown in Table 2. For example, in Example 9, a coating composition was prepared as follows. In a plastic bottle, ethanol 3.862 g, decyltrimethoxysilane (specific gravity 0.903, purity 0.970) 0.433 g, tetraethoxysilane (specific gravity 0.935, purity 0.970) 1.329 g, Aerosil (registered trademark) ) 0.58 g of a solution obtained by dispersing 300 in 10% ion-exchanged water and 0.495 g of hydrochloric acid were added. The solution was then stirred with a stirrer for 24 hours. The solution was then stored at a temperature of 22 ° C. for 24 hours. Next, 20 g of isopropanol was added to 0.38 g of the solution and diluted to prepare a coating composition of Example 9 (solid content concentration 0.5%).

＊１：比較例１は（Ｂ）成分／（Ａ）成分のモル比が０／４であり、比較例２は（Ｂ）成分／（Ａ）成分のモル比が１／０である。
＊２：「○」は触媒を配合したことを表し、「−」は触媒を配合しなかったことを表す。

* 1: In Comparative Example 1, the molar ratio of component (B) / (A) is 0/4, and in Comparative Example 2, the molar ratio of component (B) / (A) is 1/0.
* 2: “◯” represents that a catalyst was blended, and “−” represents that a catalyst was not blended.

  About each prepared coating composition of Examples 1-29 and Comparative Examples 1-10, the coating film was formed as follows. Each coating film was measured and evaluated for dynamic contact angles before and after the submersion test, water drop sliding speed, oil drop sliding speed, and powder adhesion resistance, as described later. The results are also shown in Table 2.

(Formation of coating film)
On a 7 cm × 15 cm aluminum plate at a temperature of 25 ° C. and a relative humidity of 50% RH, a bar coater No. 7 was applied to form a coating film. An aluminum plate (hereinafter referred to as a coated plate) on which the coating film was formed was allowed to stand for 24 hours and dried.

(Submerged test)
The whole coating films of Examples 1 to 29 and Comparative Examples 1 to 10 were immersed in a beaker filled with ion-exchanged water and allowed to stand at room temperature for 3 hours.

(Measurement of dynamic contact angle)
The dynamic contact angle is determined by A. Hozumi and T. J. et al. It calculated | required by the method as described in McCarthy, Langmuir, 26,2567 (2010). A dynamic contact angle of 10 ° or less indicates good liquid repellency.

(Evaluation of liquid repellency by sliding time)
After the coating film was fixed at an angle of 45 ° from the horizontal plane, each of 20 μL of ion-exchanged water and oil was gently placed on the coating film. And the time (second) until it moved a base 5 cm below from the place which mounted was measured. The liquid repellency was evaluated according to the following criteria. The evaluation A has better liquid repellency.
Evaluation A: Droplet moved 5 cm downward within 60 seconds Evaluation B: Droplet moved 5 cm downward after 60 seconds

(Evaluation of powder adhesion)
The powder (SPF-130MC) was formed into a layer having a thickness of 3 mm, and the film was placed on the layer so as to face the surface of the coating film formed on the coating plate. A weight was placed on the coated plate and compacted at 2000 Pa, then the coated plate was taken out, and the amount of powder remaining when tilted vertically was measured. The amount of residual powder was calculated from the difference in weight of the coated plate after the powder was adhered and before the powder was adhered. A residual powder amount of 5 mg / m ² or less indicates good powder resistance.

(Examples 30 to 34)
Using the components (A) and (B) shown in Table 1, the coating compositions of Examples 30 to 34 were prepared with the formulations shown in Table 3. In Examples 30 to 32 and 34, the content of the component (D) relative to the sum of the components (A), (B) and (D) was set as follows.
Example 30: content of component (D) 0.02 mol / L
Example 31: (D) component content 8 mass%
Example 32: Content of component (D) 0.1 mol / L
Example 34: (D) component content 10 mass%

＊３：「○」は触媒を配合したことを表し、「−」は触媒を配合しなかったことを表す。

* 3: “◯” represents that the catalyst was blended, and “−” represents that the catalyst was not blended.

  In Examples 30 to 32, a coating film was formed in the same manner as in Example 9. In Examples 33 and 34, the coated plate was further placed in a desiccator containing 70 mL of 25% aqueous ammonia. And it left still at 50 degreeC for 96 hours, and the coating film was base-treated.

  About the coating film of Example 9, 30-34, the submergence test shown below was done, and the dynamic contact angle before and after the submergence test, the sliding speed of the water droplet, and the sliding speed of the oil droplet were measured and evaluated. Moreover, about the coating film of Examples 30-34, the powder-proof adhesion before a submergence test was also evaluated. These results are also shown in Table 3.

(Submerged test)
The entire coating film was immersed in a beaker filled with ion exchange water and allowed to stand at room temperature for 6 hours.

  ADVANTAGE OF THE INVENTION According to this invention, the coating composition which can form the coating film which has liquid repellency and powder-proof adhesion property can be provided. Moreover, according to this invention, the coating film which has liquid repellency and powder-proof adhesion property can be provided. Moreover, according to the present invention, an article having liquid repellency and powder resistance can be provided.

Claims (3)

(A) Trialkoxyalkylsilane represented by the general formula (R ¹ O) ₃ SiR ² (wherein R ¹ is independently an alkyl group having 1 to 4 carbon atoms, and R ² is carbon An alkyl group of 6 to 16),
And (B) the general formula ^(R 3 _O) (wherein, ^{R 3} are each independently an alkyl group having 1 to 4 carbon atoms) tetraalkoxysilane represented by 4 Si,
(C) inorganic nanoparticles,
(D) a catalyst;
Including
The molar ratio (B) / (A) between (B) and (A) is 0.3 to 200,
The coating composition whose quantity of (C) with respect to the total amount of said (A), (B) and (C) is 0.1-20 mass%.   A coating film formed using the coating composition according to claim 1.   An article having the coating film according to claim 2 on a surface thereof.