JP2019112578A - Coating agent composition - Google Patents

Abstract

To provide a thin film coating agent composition having excellent hydrophilicity and good durability to a mirror surface under an environment in contact with moisture such as back mirrors of a vehicle, a bathroom or a wash stand.SOLUTION: There is provided a coating agent composition which comprises the following (a) to (e): (a) silica particles, (b) an active hydrogen group-containing alkoxysilane compound, (c) a hydrolyzable group-containing silicone oligomer, (d) a hydrolysis catalyst and (e) a solvent or a diluent.SELECTED DRAWING: None

Description

The present invention relates to a coating composition, and more particularly to a coating composition capable of obtaining a hydrophilic thin film coating layer excellent in durability to metal surfaces, painted surfaces or resin surfaces of automobile bodies and trains. .

In the past, glass members that require high visibility such as mirrors installed in a bathroom or wash basin in a home, a side mirror of an automobile, etc. have dew condensation caused by the adhesion of fine water droplets on their surface Is disliked. Therefore, to these members, a hydrophilic coating composition has been applied and applied (for example, to form a thin film that spreads thinly on the glass surface without water droplets even when water adheres) (for example, Patent document 1 etc.).

JP 2001-337211 A

However, these hydrophilic coating agent compositions do not have sufficient durability of the coating film, and when the portion to be coated is subjected to a load such as being exposed to moisture for a long period of time, the coating film becomes hydrophilic. It was easily lost and had problems with long-term reliability.

As described above, it was difficult to satisfy the required properties with the conventional coating agent composition, but as a result of intensive studies to improve these properties according to the present invention, by using the coating agent composition having the following configuration , I have found that this can be achieved. That is, the first embodiment of the present invention is a coating composition comprising the following (a) to (e).
(A) Silica particle (b) active hydrogen group-containing alkoxysilane compound (c) hydrolyzable group-containing silicone oligomer (d) hydrolysis catalyst (e) solvent or diluent

The present invention also includes the following embodiments.
In the second embodiment, (b) is contained in 0.01 to 5.0 parts by mass and (c) is contained in 0.005 to 1.0 parts by mass with respect to 1 part by mass of (a). It is the coating agent composition as described in said 1st embodiment.

The third embodiment contains 0.1 to 1.0 parts by mass of (b) and 0.005 to 0.1 parts by mass of (c) per 1 part by mass of the (a), It is the coating agent composition as described in any of the said 1st or 2nd embodiment.

The fourth embodiment is the coating composition according to any of the first to third embodiments, wherein the (a) and the (b) are previously mixed and stirred in the (e). It is.

A fifth embodiment is the coating agent composition according to the fourth embodiment, wherein ultrasonic wave irradiation is performed in the mixing and stirring process.

A sixth embodiment is the coating composition according to any one of the first to fifth embodiments, wherein (b) is an amino group-containing alkoxysilane compound.

A seventh embodiment is the coating composition according to the sixth embodiment, wherein the amino group-containing alkoxysilane compound of (b) is γ-aminoalkyltrialkoxysilane.

The eighth embodiment further comprises (f) a silicate compound represented by the following structural formula, or a partial hydrolytic condensate thereof, according to any of the first to seventh embodiments. It is a coating agent composition.
R ³ _y -Si (OR ⁴ ) _4-y
(Wherein R ³ and R ⁴ are each independently an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 8 carbon atoms, which may have a substituent, and y is 0 to 3) Is an integer of

The ninth embodiment is the coating agent composition according to any one of the first to eighth embodiments, wherein the (a) contains a hydrophilic silica which is not surface-treated.

The tenth embodiment is the coating agent composition according to any one of the first to ninth embodiments, wherein (e) is selected from alcohol solvents or petroleum solvents.

The eleventh embodiment is the coating composition according to any one of the first to tenth embodiments, wherein the average particle diameter of (a) is in the range of 1 to 25 nm. is there.

A twelfth embodiment is the coating composition according to any one of the first to eleventh embodiments, which is applied to an automobile exterior steel sheet.

In the thirteenth embodiment, the coating composition according to any one of the first to eleventh embodiments is applied to the surface of a substrate, and the reaction component is crosslinked on the substrate together with the volatilization of the solvent. It is a coating layer formation method which forms a cured coating film.

A twelfth embodiment is a coating layer formed by the method for forming a coating layer according to the eleventh embodiment.

By using the coating agent composition of the present invention, it is possible to apply a thin film coating layer excellent in hydrophilicity and durability, which is suitable for application to a steel plate such as an automobile exterior.

The details of the present invention will be described below. (A) contained in the coating agent composition of the present invention is a silica particle, and when a coating film is formed by the coating agent composition of the present invention, excellent hydrophilicity is achieved in concert with (b) described later. It is a component to be expressed. Specifically, when the coating film according to the present invention is formed on a substrate such as glass, metal, or a coated steel plate, even if water adheres, it does not become a ball of water droplets by the action of the component, The effect is that the moisture spreads thinly and forms a film. Here, any of dry silica particles and wet silica particles may be used as the silica particles, or a mixture of plural types having different average particle diameters may be used. In the present invention, commercially available known silica particles may be used, and examples of fumed silica products include various AEROSIL products manufactured by Nippon Aerosil Co., Ltd., various CAB-O-SIL products manufactured by Cabot Corporation, and products manufactured by Tokuyama Corporation. Various rheosil etc. can be selected, and as amorphous silica products, for example, various Nipsil of Tosoh silica products, various sylysia of Fuji Silysia products, various Silo Hobic, various Carplex of DSL Japan products, various SIPER NAT and the like are known, and can be appropriately selected from these according to the purpose.

More preferable as the above (a) is a hydrophilic silica particle whose surface is not subjected to hydrophobic treatment. In the present invention, the average particle diameter of (a) is not limited, but preferably in the range of 0.1 to 100 nm, more preferably in the range of 0.5 to 50 nm And more preferably in the range of 1 to 25 nm. By using what is in the said range, the coating agent composition of this invention can make compatible coating property at the time of coating-film formation, and smooth coating-film formation. Here, the average particle diameter means the average diameter of primary particles measured by observation with an electron microscope or the like.

The commercial product (a) which can be suitably used in the present invention is not particularly limited. For example, Aerosil 380 (average particle diameter 7 nm, hydrophilic fumed silica), Aerosil 300 (average), manufactured by Nippon Aerosil Co., Ltd. Particle size 7 nm, hydrophilic fumed silica), Aerosil 200 (average particle size 12 nm, hydrophilic fumed silica), Aerosil 150 (average particle size 14 nm, hydrophilic fumed silica), Aerosil 130 (average particle size about 160 nm, Hydrophilic fumed silica), Aerosil 90 G (average particle size 20 nm, hydrophilic fumed silica), Aerosil 50 (average particle size 30 nm, hydrophilic fumed silica), Aerosil OX 50 (average particle size 40 nm, hydrophilic fumed silica) Etc. can be appropriately selected, and these are used in combination of two or more It may be.

(B) contained in the coating agent composition of the present invention is an active hydrogen group-containing alkoxysilane compound, and in the coating agent composition of the present invention, it reacts with the reactive group present on the surface of (a). It is a component necessary to impart hydrophilicity to the coating film by further enhancing the affinity of this to water. The active hydrogen group-containing alkoxysilane compound is not particularly limited as long as it is a silane compound containing an active hydrogen group and an alkoxy group in the molecule, and known compounds can be used. In addition, as a reactive group which exists on the surface of said (a), it is assumed that they are a hydroxyl group, an alkoxy group, etc.

Here, examples of the active hydrogen group include carbinol group, amino group, silanol group, mercapto group and the like, but in the present invention, amino group is particularly desirable. The amino group is preferably bonded to a linear or cyclic alkyl skeleton with an amino group linked, and more preferably an amino group linked to the end of the linear alkyl group. Most preferably, it is a γ-aminoalkyl group. The alkoxy group is an alkoxy group having a carbon number of about 1 to 4 selected from methoxy group, ethoxy group, propoxy group, 2-propoxy group, butoxy group, 2-butoxy group, t-butoxy group and the like Desirably, it is desirable to have 1 to 3, preferably 2 to 3, and particularly preferably 3 in the molecule (b). In addition, an amino group is connected with the terminal of a chain | strand-shaped alkyl group, and the general name of the silane compound which has three alkoxy groups is called gamma-aminoalkyl trialkoxysilane.

The commercial product (b) which can be suitably used in the present invention is not particularly limited. For example, KBM-602 (N-2- (N-2 (N-2- Aminoethyl) -3-aminopropylmethyldimethoxysilane), KBM-603 (N-2- (aminoethyl) -3-aminopropyltrimethoxysilane), KBM-903 (3-aminopropyltrimethoxysilane), KBE- 903 (3-aminopropyltriethoxysilane), A-1100 (3-aminopropyltriethoxysilane) product of Momentive Performance Materials Japan Ltd. product, A-1110 (3-aminopropyltrimethoxysilane), A1120 (N- (2-aminoethyl) -3-ami Propyltrimethoxysilane), A-2120 (N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane), Z-6011 (3-aminopropyltriethoxysilane) manufactured by Dow Corning Japan Ltd., Z- 6610 (3-aminopropyltrimethoxysilane), OFS-6020 (N-2- (aminoethyl) -3-aminopropyltrimethoxysilane), and as a mercapto group-containing alkoxysilane compound, KBM-manufactured by Shin-Etsu Silicone Co., Ltd. 802 (3-Mercaptopropylmethyldimethoxysilane), KBM-803 (3-Mercaptopropyltrimethoxysilane), A-189 (3-Mercaptopropyltrimethoxysilane) product of Momentive Performance Materials Japan LLC, A-1891 (3-mercaptopropyltriethoxysilane), A-LINK 599 (3-octanoylthio-1-propyltriethoxysilane), Z-6062 (3-mercaptopropyltrimethoxysilane) manufactured by Dow Corning Japan Ltd., etc. These can be selected appropriately, and these may be used in combination of two or more kinds.

The amount of the composition (b) in the present invention is preferably 0.01 to 5.0 parts by mass, more preferably 0.05 to 3.0 parts by mass with respect to 1 part by mass of the (a). Particularly preferably, it is in the range of 0.1 to 1.0 parts by mass. Within the above range, the coating composition of the present invention can acquire appropriate hydrophilicity and can suppress the aggregation of (a) upon storage. The component (b) is preferably a monomer, but may be a polymer obtained by polymerizing a plurality of molecules, that is, an oligomer. When it is a multimer, even if it has a hydrolyzable group in the molecule, it needs to contain an active hydrogen group separately from this. When it is a compound which has both a hydrolysable group and an active hydrogen group, it shall be included in the category of (b) in distinction from the below-mentioned (c).

Furthermore, in the present invention, preferably, (a) and (b) have been treated by mixing and stirring in (e) solvent or diluent to be described later. By the treatment being performed, the (b) can be sufficiently contacted with the (a), and the surface of the (b) will be uniformly modified. On the other hand, when the mixing and stirring process is not performed only with these components in advance, the component (b) reacts with other reactive components in the composition, for example, (c), (d), (f) described later. As a result, the surface of (a) may not be sufficiently modified.

Here, in the present invention, in the mixing and stirring process, it is particularly preferable to perform ultrasonic irradiation as a means of the process. The ultrasonic treatment referred to here is to apply an impact by a sound wave having a frequency of about 20 kHz to the object to give microscopic reversible or irreversible changes in the surface state, internal structure and the like. The purpose of the treatment is to maintain the particle size so that the silica particles do not cause secondary aggregation to increase the apparent particle size. By performing the ultrasonic treatment, the coating agent composition of the present invention can form a uniform coating film, and as a result, excellent hydrophilicity and coating film durability can be exhibited. As the conditions for the ultrasonic treatment, the treatment temperature is in the range of normal temperature to 100 ° C., preferably about 25 to 50 ° C., and the treatment time is 1 minute or more, more preferably 3 to 120 minutes, further preferably It is desirable to set it as 5 to 120 minutes. The (a) and (b) subjected to the ultrasonic treatment are stored in the state of being dispersed in the solvent or the dispersion medium which is the above (e) in order to prevent the (a) from being aggregated again. It is desirable to use as appropriate.

(C) contained in the coating agent composition of the present invention is a hydrolyzable group-containing silicone oligomer, and when a coating film is formed by the coating agent composition of the present invention, the coating film gives strength to the coated film as a cured film It is an ingredient necessary to establish it. Here, the hydrolyzable group-containing silicone oligomer is obtained by partially hydrolyzing an alkoxysilyl compound having 1 to 4 functions with a known catalyst such as an acid, a base, an organic tin compound, an organic titanium compound, etc. In the present invention, it is a compound having a size of about 10 to 30 in general, which is also called partial hydrolytic condensation, and which has a hydrolyzable group derived from the above alkoxysilyl compound at the molecular chain terminal or side chain etc. A silicone compound having a linear or three-dimensional network structure. The compound is typically a partial hydrolysis condensate of an alkoxysilyl compound represented by the following chemical formula (1).

R ¹ _x -Si (OR ² ) _4-x Chemical formula (1)
Here, R ¹ and R ² are each independently an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 8 carbon atoms which may have a substituent, or an amino group, a mercapto group, glycidyl It is a functional group selected from organic groups containing a group, an acryloyl group, a methacryloyl group, and a vinyl group. R ¹ is preferably an aliphatic hydrocarbon group selected from a methyl group, an ethyl group, an n-propyl group and an iso-propyl group, particularly preferably a substituent selected from a methyl group and an ethyl group. R ² is preferably an aliphatic, alicyclic or aromatic hydrocarbon group, and more preferably a substituent selected from a methyl group and an ethyl group. In the formula, x is an integer of 0 to 3, preferably 0 or 1, and particularly preferably 1 or even a mixture in which different numerical values are mixed in the range. Good. As a manufacturing method of the said (b), adding a well-known hydrolysis catalyst to the compound shown by the said Structural formula and obtaining by causing partial hydrolysis-condensation by stirring, heating in presence of water | moisture content it can. Here, in the above structural formula, when x is 0 or 1, when the polymer of the compound becomes linear, it has an alkoxy group represented by (OR ² ) in the side chain, or Coalescing does not form a linear structure, but constitutes a three-dimensional crosslinked body, and partially contains an alkoxy group in the structure. As the compound, x may contain 2 or 3. However, in order to effectively add an alkoxy group to the structure of (b), x is preferably 0 or 1. . Here, the thing of only x = 3 is not used, and when x = 3 exists, the thing of x = 0-2 shall coexist simultaneously. As described in the paragraph (b), silicone oligomers having an active hydrogen group in addition to a hydrolyzable group in the same molecule are included in the category of (b) in distinction from (c).

As the said (c), a commercial item can be used suitably, For example, X-40-9225, X-40-9227, X-40-9246, X-40-9250, X-40-2327, KC-89S KR-400, KR-401, KR-401N, KR-500, KR-510, KR-513, KR-515, KR-516, KR-517, KR-9216, KR-213, X -22-4309 (above, Shin-Etsu Chemical Co., Ltd. product), XC96-B0446, XR31-B1410, XR31-B2733, XR31-B2230, TSR165, XR31-B6667, XR31-B1763 (above, Momentive Performance Materials · Japan Limited company product), SILRES MSE 100, SILRES H44 (or later , Can be exemplified Wacker Asahi Kasei Silicone Co., Ltd. product) and the like, they may be used in combination of plural kinds may be used alone. Further, in the present invention, a commercial product containing a curing catalyst in advance may be used as (c), and such commercial products include KR-400, KR-401, X as one containing a phosphoric acid compound in the catalyst. -40-2327 (above, Shin-Etsu Chemical Co., Ltd. product) etc. are known. The component preferably has a viscosity at 25 ° C. in the range of 0.01 to 250 mm ² s ⁻¹ , more preferably 0.01 to ²⁰⁰ mm ² s ⁻ , from the viewpoint of handling during production. It is particularly desirable to use ^{one in} the range of ¹ .

The amount of the composition (c) in the present invention is preferably 0.005 to 1.0 parts by mass, and more preferably 0.008 to 0.5 parts by mass with respect to 1 part by mass of the (a). Particularly preferably, it is in the range of 0.01 to 0.1 parts by mass. Within the above range, the coating composition of the present invention can acquire appropriate hydrophilicity and can ensure storage stability.

In the present invention, (d) is a hydrolysis catalyst, and by including a catalytic amount in the coating agent composition of the present invention, as a hydrolyzable group contained in the above (b) and (c), or as an optional component It is a substance for causing an alkoxysilyl group contained in (f) described later to be hydrolyzed with moisture in the air or the like to form a cured film. The composition amount of (d) in the coating agent composition of the present invention is not particularly limited and may be a catalytic amount, but preferably the hydrolyzable group-containing compound contained in the coating agent composition, specifically It is desirable that it is 0.0001-0.1 mass part to a total of 1 mass part of the above-mentioned (c) and the below-mentioned (f), and it is desirable that it is the range of 0.0005-0.05 mass part suitably.

Known compounds can be used as (d), and organic metal compounds such as organic tin compounds, organic titanium compounds, organic zirconium compounds, organic aluminum compounds, inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid compounds, Organic acids such as p-toluenesulfonic acid and various aliphatic or aromatic carboxylic acids, ammonia, inorganic bases such as sodium hydroxide, tributylamine, 1,5-diazabicyclo [4.3.0] nonene-5 (DBN And organic bases such as 1,8-diazabicyclo [5.4.0] undecene-7 (DBU), etc., as appropriate. Specific examples of the organic metal compounds include dibutyltin dilaurate, dibutyltin dioctate, dibutyltin diacetate, dioctyltin dilaurate, dioctyltin dioctate, dioctyltin diacetate, dibutyltin bisacetyl acetate, dioctyltin bisacetyl laurate, tetrabutyl Examples thereof include titanate, tetranonyl titanate, tetrakis ethylene glycol methyl ether titanate, tetrakis ethylene glycol ethyl ether titanate, bis (acetylacetonyl) dipropyl titanate, aluminum acetylacetone, aluminum trisethylacetoacetate, etc. Or two or more of them may be used in combination, or in combination with an inorganic acid selected from the above-mentioned hydrochloric acid, sulfuric acid and phosphoric acid compounds. Good. In the present invention, organic metal compounds selected from the above organic tin compounds, organic titanium compounds and organic aluminum compounds, or inorganic acids selected from hydrochloric acid, sulfuric acid and phosphoric acid compounds are preferable, and the above inorganic acids are more preferable. More desirable, and particularly preferred is a phosphoric acid compound.

The (e) contained in the coating composition of the present invention is a solvent or a diluent, and is for uniformly mixing and dispersing the components (a) to (d) in the coating composition of the present invention. It is a medium. As the solvent or diluent, any material can be selected as appropriate according to the required properties, as long as the material is capable of uniformly mixing and dispersing the above-mentioned components. When using substances having the property of reacting with the coating agent composition of the present invention may cause problems in storage stability, they should be considered to be excluded. From the viewpoint of workability when applying the coating composition of the present invention to form a coating layer, a compound having a high volatility to a certain degree, preferably having a boiling point of 180 ° C. or less, and in the case of a mixture, an initial distillation It is preferable that the point is 180 ° C. or less.

Examples of (e) that can be preferably used in the present invention include alcohol compounds, ester compounds, ether compounds, ketone compounds, hydrocarbon compounds such as paraffins and naphthenes, and halogens formed by halogenating these. It is possible to appropriately select from modified hydrocarbon compounds, petroleum solvents and the like. There is no particular limitation, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, tert-butanol, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, isopropyl acetate, butyl acetate, ethyl ether, THF, 1,4-dioxane acetone, methyl ethyl ketone, benzene, toluene, xylene, chlorobenzene, acetonitrile, n-hexane, n-heptane, cyclohexane, methylcyclohexane, dichloromethane, chloroform, trichlene, tetrachloroethane, gasoline, petroleum ether, naphthene petroleum distillation Examples thereof include solvents, paraffinic petroleum distillation solvents, isoparaffinic petroleum distillation solvents, etc. These may be used alone or in combination of two or more. In the present invention, alcohol compounds having 2 or more carbon atoms, ketone compounds, saturated aliphatic hydrocarbon compounds and naphthene hydrocarbon compounds are preferable from the viewpoints of working environment such as odor and safety, and volatility. Preferably, it is one or more selected from ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol and tert-butanol.

There is no particular limitation on the composition amount of (e) in the coating agent composition of the present invention, but it is preferably in the range of 1 to 100 parts by mass with respect to 1 part by mass of the (a). It is in the range of 75 parts by weight, particularly preferably 5 to 50 parts by weight. By being below the said upper limit, the coating agent composition of this invention can maintain moderate volatility and coating film formability, and when it is more than the said lower limit, the coating agent composition of this invention is Appropriate work efficiency can be secured.

In addition, in the coating agent composition of the present invention, optional additive components can be appropriately added as long as the characteristics are not impaired. For example, non-reactive silicone oils, alkoxysilyl group-containing compounds other than the above (b) and (c), adhesion imparting agents such as coupling agents other than the above (b), plasticizers, antiaging agents, rust inhibitors, Components such as colorants, surfactants, rheology modifiers, ultraviolet light absorbers, infrared light absorbers, fluorescent agents, abrasives, perfumes, fillers and the like can be selected. In particular, as the alkoxysilyl group-containing compound other than the above (b) and (c), it is preferable to contain (f) a silicate compound represented by the following chemical formula (2) or a partial hydrolysis condensate thereof.

R ³ _y -Si (OR ⁴ ) _4-y Chemical formula (2)
Here, R ³ and R ⁴ are each independently an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 8 carbon atoms which may have a substituent, and preferably a methyl group And an ethyl group. Here, y in the said compound is an integer of the range of 0-3, and if it is the said range, the thing of a different numerical value may be mixed. Although y = 4 may be included, only y = 4 is not included in the scope of the present invention, and at least y = 0 to 3 should be included in the present invention. . In the present invention, preferably, y = 0 to 2, more preferably y = 0, 1, and particularly preferably y = 0. Further, in the present invention, it is desirable that the R ⁴ is an aliphatic hydrocarbon group, and particularly preferably any one selected from the methyl group, the ethyl group, the n-propyl group and the i-propyl group as the R ^4. It is to be species or more. Further, the (f) may be a partially hydrolyzed condensate in which the above compound is condensed to about 10 molecules. The most preferable compound in the present invention is ethylsilicate having a monomer structure in which y = 0 and R ⁴ = ethyl group.

When the coating agent composition of the present invention contains the above (f), when forming a coating film by the coating agent composition, the (f) is incorporated on the cross-linked structure of the curing component consisting of the above (c) As a result, the crosslink density is enhanced, the coating film is reinforced, and the durability of the coating film is enhanced. A commercially available product can be appropriately used as (f), and for example, ethyl silicate 28 (tetraethoxysilane), ethyl silicate 40 (partial hydrolytic condensate of ethyl silicate 28 described above, average pentamer), ethyl silicate 48 ( Partial hydrolysis condensate of ethyl silicate 40, average 10-mer), methyl silicate 51 (partial hydrolysis condensate of tetramethoxysilane, average tetramer), methyl silicate 53 A (partial hydrolysis of methyl silicate 51) Condensate, average 7-mer), N-propyl silicate (tetranormal propoxysilane), N-butyl silicate (tetranormal butoxysilane) (above, products of Corcoat Co., Ltd.), etc. can be mentioned, and these are used alone However, multiple types may be used in combination.

The composition amount of (f) in the coating agent composition of the present invention is in the range of 0.05 to 10 parts by mass, preferably 0.1 to 5 parts by mass, particularly preferably 1 part by mass of the (a). To 0.25 to 2.5 parts by mass. By being above the lower limit, appropriate coating film strength can be secured, and by being below the upper limit, it is possible to have appropriate flexibility of the coating.

The coating agent composition of the present invention can be applied to substrates of various metals, glasses, ceramics, resins, etc., but from the viewpoint as a substrate for which hydrophilicity is particularly required, application to glass surfaces is preferred. Desirably, it is desirable to apply to a mirror surface in an environment in contact with moisture, such as a car rearview mirror, a bathroom or a wash basin. By applying to these substrates, a thin film of water is formed when the glass surface is in contact with moisture, so that the surface with no haze and excellent appearance of visibility can be maintained for a long time It becomes.

The application means of the coating composition of the present invention is not particularly limited, and any appropriate application means such as hand coating using a fiber impregnated with the composition, brush coating, machine coating using an automatic machine, etc. Can be used. Particularly preferably in the context of the present invention is the application of the following method. That is, an appropriate amount of the coating composition of the present invention is impregnated into a dried sponge or waste fiber, which is spread thinly on the surface of the substrate by hand, and volatilized by natural drying or forced drying using a dryer or the like. Allow to volatilize. After that, it is a method of finishing by wiping up the said coated surface with another dry cloth or a microfiber waste etc. At this time, as the reaction component (c) contained in the composition, the hydrolysis reaction proceeds by the action of the hydrolysis catalyst (d) to form a cured coating on the substrate. The thickness of the cured coating film is preferably in the range of about 0.01 to 100 μm, preferably 0.05 to 75 μm, and particularly preferably 0.1 to 50 μm. When the coating layer is in the above range, it is possible to achieve both good water repellency, water sliding ability, workability at the time of coating, durability, and appearance.

Although the mechanism which forms the coating film which had the outstanding hydrophilic characteristic by the coating agent composition of this invention is not clear, it is thought that it is as follows by assumption. That is, when (c), which is the main curing component of the present invention, is crosslinked and cured by a hydrolysis reaction, the surface is coated with (a) which is a solid modified with a compound (b) having an active hydrogen group. It is incorporated into a film and forms a cured film rich in active hydrogen groups on the surface. When the active hydrogen group is compatible with moisture in the air such as rain, it exhibits hydrophilicity to realize a cured coating film excellent in hydrophilicity.

Hereinafter, the effects of the present invention will be described in detail by way of examples, but these examples are not intended to limit the aspects of the present invention. In addition, the thing of the coating agent composition which prepared and evaluated in each Example and comparative example etc. is only hereafter called a "composition."

[Method of preparing composition]
Each composition evaluated by the Example of this invention and the comparative example was prepared with the following method. In a sealed vial, (a) was added to (e) of a predetermined mass described in Table 1 and agitation was performed under a 25 ° C. environment, and a predetermined amount of (b) or (b ′) was added thereto (Comparative example 3). While the vial was sealed, the mixture was subjected to a mixing / stirring process by irradiating it with ultrasonic waves of 20 kHz for 10 minutes using an ultrasonic generator “vibra cell” manufactured by SONIC Corporation. Thereafter, each composition was prepared by sequentially adding (c) (including (d)) and (f) thereto and stirring for 10 minutes. In Comparative Example 3, the composition was prepared without adding (b) to the composition.

The characteristics of the coating agent composition of the present invention were evaluated by the following methods.
[Method of making test piece]
Each composition shown in the table is soaked in the tissue paper in such an amount that the surface half of the tissue gets wet (about 2 ml) and thinly applied by hand on the surface of a transparent glass plate (50 mm × 20 mm × 5 mm) After spreading and leaving in a room at 25 ° C. for 10 minutes, the excess was wiped off with a dry microfiber cloth to make the surface free from any spots of the composition. The thing of this state was made into the "initial" test piece. Ion-exchanged water was sprayed 50 times from the position 10 cm away from the "applied" test piece's coated surface straight from a distance of 10 cm, and after removing water by air blow, "durability" test piece did.

[Contact angle evaluation method]
A drop of ion-exchanged water (about 0.005 to 0.05 ml) is dropped onto the surface of each of the "initial" and "durability" test pieces with a syringe, and the contact angle of water is measured using a contact angle meter (DM-500). , And manufactured by Kyowa Interface Science Co., Ltd.), and the hydrophilicity was evaluated by the value of the contact angle. The desirable contact angle in the coating agent composition of the present invention is a value (hereinafter also referred to as initial contact angle) measured on the "initial" test piece is about 20 ° or less, more preferably 15 ° or less. Also, from the viewpoint of durability in long-term use, it is desirable that the measured value of the contact angle by the “durability” test piece (hereinafter also referred to as a durable contact angle) be a variation of less than 5 with respect to the value of the initial contact angle. .

[Raw material of composition]
The raw materials contained in each composition prepared by the Example of this invention, and the comparative example used the following material, and described each composition quantity in Table 1.
(A) Silica particles · AEROSIL 200: Nippon Aerosil Co., Ltd. product, average particle diameter 12 nm, hydrophilic fumed silica without surface treatment, specific surface area 200 ± 25 m ² / g according to BET method
(B) Active hydrogen group-containing alkoxysilane compound and its comparative component · KBM-903: Shin-Etsu Silicone Co., Ltd. product, 3-aminopropyltrimethoxysilane KBM-303: Shin-Etsu Silicone Co., Ltd. product, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane KBM-503: Shin-Etsu Silicone Co., Ltd. product, 3-methacryloxypropyltrimethoxysilane (c) hydrolyzable group-containing silicone oligomer X-40-2327: Shin-Etsu Chemical Co., Ltd. product, Partial hydrolytic condensate of a compound in which R ¹ and R ² are both methyl groups in chemical formula (1) and x = 1 to 3, viscosity 0.9 mm ² s ^{−1 at} 25 ° C., (d) hydrolysis catalyst (E) solvent or diluent, 2-pro containing phosphoric acid compound at a concentration of 5 to 10% as Panol: Nacalai Tesque, Inc. products, reagents, etc. (f) Silicate compound · Ethyl silicate 28: Colcoat Co., Ltd. product, R ⁴ in the chemical formula (2) is an ethyl group, a compound of y = 0, chemical name tetraethoxysilane

As a reference example, the same steps as the preparation method of the composition except that (a) and (b) were mixed and stirred in (e) without ultrasonication when the composition was prepared. Then, a composition having the same composition as Example 1 was prepared. In the composition of the reference example, since the initial contact angle became a value exceeding 20 °, the durable contact angle was not measured.

From the results shown in Table 1, all the compositions containing the composition of the present invention at the predetermined composition ratio had the desired initial contact angle, and the durable contact angle did not change much more than the initial value. However, in Example 3 in which the composition amount of (c) exceeds 0.1 parts by mass with respect to 1 part by mass of (a), it was recognized that the durable contact angle tends to slightly increase. Instead of (b), 3-aminopropyltrimethoxysilane (KBM-903) and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (KBM) which are alkoxysilane compounds having no active hydrogen group in the molecule In each of Comparative Examples 1 and 2 using (-303) and Comparative Example 3 not containing a component corresponding to (b), the contact angle becomes excessive in both initial stage and durability, and it is suitable for formation of a hydrophilic film. It was not a thing.

The coating composition of the present invention has excellent hydrophilicity and good durability, and is particularly hydrophilic to a mirror surface in an environment in contact with water, such as a car rearview mirror or a bathroom or a wash basin. It is a useful thing which can be used suitably in forming the thin film coating layer for giving property.

Claims (14)

Coating agent composition comprising the following (a) to (e).
(A) Silica particle (b) active hydrogen group-containing alkoxysilane compound (c) hydrolyzable group-containing silicone oligomer (d) hydrolysis catalyst (e) solvent or diluent The said (b) is 0.01-5.0 mass parts with respect to 1 mass part of said (a), and (c) contains 0.005-1.0 mass part of said, It is a thing of the said Claim 1. Coating composition. The said 1 or 2 in which 0.1 to 1.0 mass part of (b) and 0.01 to 0.1 mass part of (c) are contained with respect to 1 mass part of said (a). Coating composition as described. The coating agent composition according to any one of claims 1 to 3, wherein the (a) and the (b) are mixed and stirred in the (e) in advance. The coating agent composition according to claim 4, wherein irradiation of ultrasonic waves is performed during the mixing and stirring process. The coating agent composition according to any one of claims 1 to 5, wherein (b) is an amino group-containing alkoxysilane compound. The coating agent composition according to claim 6, wherein the amino group-containing alkoxysilane compound is γ-aminoalkyltrialkoxysilane. The coating agent composition according to any one of claims 1 to 7, which further contains (f) a silicate compound represented by the following structural formula, or a partial hydrolytic condensate thereof.
R ³ _y -Si (OR ⁴ ) _4-y
(Wherein R ³ and R ⁴ are each independently an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 8 carbon atoms, which may have a substituent, and y is 0 to 3) Is an integer of The coating agent composition according to any one of claims 1 to 8, wherein (a) comprises hydrophilic silica not subjected to surface treatment. The coating agent composition according to any one of claims 1 to 9, wherein the (e) is selected from alcohol solvents or petroleum solvents. The coating agent composition as described in any one of the said embodiment which comprises what has an average particle diameter of said (a) in the range of 1-25 nm. The coating agent composition according to any one of claims 1 to 11, wherein the coating agent composition is applied to an automobile exterior steel sheet. The coating which forms a cured coating film by apply | coating the coating agent composition of any one of the said Claims 1-11 on the base-material surface, and carrying out the crosslinking reaction of the reaction component on a base material with volatilization of a solvent Layer formation method. The coating layer formed by the coating layer formation method of the said Claim 13.