JPH06220428A - Surface-modified antifogging film - Google Patents

Abstract

PURPOSE:To form the subject film which is excellent in antifogging ability and has a good effect of preventing water droplets from attaching and a good visibility by forming a film composed of an alumina sol, a silica sol and specific compounds on a film formed by curing a specific coating composition. CONSTITUTION:A film made from a coating composition comprising, as the main components, an alumina sol, a silica sol, a water-soluble or water- dispersible organic compound and a compound selected from organosilicon compounds of formula I or II {wherein R<1>, R<3> and R<5> are each an epoxidized 4-14C organic group; R<2>, R<4> and R<6> are each a 1-14C [halogen, SH, CN, (meth) acryloxy or NH2 substituted] hydrocarbon group; X and Q are each a hydrolyzable group; (a), (c) and (e) are each 0, 1 or 2, and (a+b), (c+d) and (e+f) are each 0, 1 or 2; and Y is a 2-40C organic group} and hydrolyzates thereof is formed on a film made by curing a coating composition comprizing PVA and a crosslinking agent as the main components to obtain the objective film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-modified anti-fogging film, and more particularly, it is suitable for surface modification of inorganic glass and plastic materials and has excellent durability and anti-fogging property and a function of preventing water droplet adhesion. And a hydrophilic coating having

[0002]

2. Description of the Related Art Plastic materials, inorganic glass, and the like have conventionally been used as a transparent base material, for example, window glass,
It is widely used for products such as mirror surfaces, spectacle lenses, and goggles. However, the drawback of the articles using these transparent substrates is that when they are used in a place of high temperature and high humidity or on a boundary surface having a large difference in temperature and humidity, dew condensation occurs on the surface of the article, and as a result, the surface of the article becomes cloudy. It is to take on. Especially among transparent substrates, window glass, spectacle lenses,
It is a serious problem that the surface of the product is easily fogged or scratched in a mirror or the like. Therefore, there have been demands for these improvements from all sides, and so far antifogging properties for various articles including transparent substrates,
Various attempts to impart durability have been proposed.

For example, a technique of using polyvinyl alcohol has been proposed as a technique of using a hydrophilic polymer for imparting durable antifogging property. For example, U.S. Pat. No. 4,127,682 proposes a polyvinyl alcohol antifog agent crosslinked with zirconium nitrate and formaldehyde. It is also known that polyvinyl alcohol is crosslinked by finely divided silica to give a water resistant coating (US Pat. No. 377377).
Further, a curable coating composition mainly composed of a complex of polyvinyl alcohol and silica has also been proposed (US Pat. No. 4,016,129). In addition, the inventors of the present invention have disclosed Japanese Patent Publication No. 62-4074 and Japanese Patent Publication No. 1-37268.
Japanese Patent Application Laid-Open No. 3-137184 proposes an antifogging film having excellent antifogging property, long-lasting property and excellent water resistance.

However, in these conventional known techniques, when the surface layer of the base material is exposed to rainwater, snow water, or the like for outdoor use, or when a large amount of dew condensation water flowing through the surface layer is generated, or in showers or the like. In such an application involving water, there is a problem that visibility is hindered by the presence of water droplets on the surface layer.

On the other hand, as a method for preventing water droplets from adhering to a base material, for example, as a method for preventing water droplets from an agricultural house, Japanese Patent Publication No. 1-31785 and Japanese Patent Laid-Open No. 62-62884 disclose inorganic materials such as silica and alumina. A technique has been proposed in which an organic silane compound, an aluminum salt, an organic anionic compound, or the like is added to a water-dispersible sol of oxide. However, although the contact angle of water on the surface layer of the base material is lowered and water droplets easily flow, it has almost no antifogging function and is not practically used.

[0006]

As described above, in the prior art, the one which has the durable anti-fogging property and the water resistance and also has the function of preventing a large amount of water droplets from adhering to the surface layer is combined. There was no The present invention is intended to solve the drawbacks of the prior art, and to provide a surface-modified anti-fog coating film having excellent anti-fogging property and excellent water resistance, and further having a water drop adhesion preventing function. With the goal.

[0007]

The present invention has the following constitution in order to achieve the above object.

"A coating film formed by curing a coating composition containing the following components A and B as the main components is provided with a film containing the coating composition containing the following components C, D and E as the main components. A surface-modified anti-fog coating.

A. Polyvinyl alcohol B. Crosslinking agent C. Alumina sol D. Silica sol E. Water-soluble or water-dispersible organic anionic compound,
At least one compound selected from the organosilicon compounds represented by the following general formula (I) or (II) and hydrolysates thereof.

[0010]

[Chemical 2] (Here, R ¹ , R ³ , and R ⁵ are epoxy-containing organic groups having ^{4 to} 14 carbon atoms, and R ² , R ⁴ , and R ⁶ are 1 to 1 carbon atoms.
4 hydrocarbon group, or a hydrocarbon group having 1 to 14 carbon atoms having a substituent selected from a halogen group, a mercapto group, a cyano group, a (meth) acryloxy group and an amino group, X
And Q represent a hydrolyzable group. a, c and e are 0, 1 or 2, respectively. Furthermore, (a + b), (c +
d) and (e + f) are 0, 1 or 2, respectively.
Y is an organic group having 2 to 40 carbon atoms. ) ”The antifogging coating of the present invention can be applied to various substrates, and is usually formed on the substrate by a coating method. The base material is not particularly limited as long as it does not impair the characteristics of the present invention, but generally, the base material whose characteristics are remarkably recognized is plastic, inorganic glass, transparent ceramic, metal, mirror surface. There are materials and the like, and particularly for an inorganic glass surface, since it has a good adhesive property, the application effect is high. Plastic and inorganic glass lenses are examples of great practical value.
The coating film of the present invention is preferably used for windows of bathrooms, mirrors, windows of automobiles or trains, door mirrors, and the like.

The polyvinyl alcohol used in the coating composition containing the components A and B of the present invention as a main component (hereinafter referred to as an antifogging coating composition) is obtained by partial hydrolysis or complete hydrolysis of polyvinyl acetate. It is a thing. Especially the average degree of polymerization is 250
Polyvinyl alcohol having a hydroxyl group of ˜3000 and a saponification degree of 70 mol% or more is preferably used in the present invention. When the average degree of polymerization is less than 250, the durability and water resistance tend to be reduced, and when it is more than 3000, the viscosity tends to increase when it is used as a paint, and it tends to be difficult to obtain a smooth coating film. Further, when the saponification degree is lower than 70 mol%, it may be difficult to exhibit sufficient performance in terms of antifogging property.

The cross-linking agent for achieving three-dimensionalization of polyvinyl alcohol is not particularly limited as long as it can insolubilize polyvinyl alcohol, and many known cross-linking agents can be used. Specific cross-linking agents include epoxy resins, melamine resins, silane coupling agents, various metal compounds, urea resins, silica fine particles and the like. Among the crosslinking agents, transparency, ease of crosslinking, hardness improvement,
A silane coupling agent is preferable from the viewpoint of many properties such as water resistance, and in particular, a compound represented by the following general formula (I) or (II), which is similar to the E component of a conventional surface-modified coating agent, and a hydrolyzate thereof are preferable. preferable.

[0013]

[Chemical 3] (Here, R ¹ , R ³ , and R ⁵ are epoxy-containing organic groups having ^{4 to} 14 carbon atoms, and R ² , R ⁴ , and R ⁶ are 1 to 1 carbon atoms.
4 hydrocarbon groups, or halogen groups, mercapto groups,
A hydrocarbon group having 1 to 14 carbon atoms having a substituent selected from a cyano group, a (meth) acryloxy group and an amino group is shown, and X and Q are hydrolyzable groups. a, c and e are 0 or 1 respectively, and b, d and f are respectively
0, 1 or 2. Furthermore, (a + b), (c +
d) and (e + f) are 0, 1 or 2. Y
Is an organic group having 2 to 40 carbon atoms. In the general formula (I), examples of the epoxy group contained in R ¹ include an aliphatic epoxy group such as a glydoxy group and an alicyclic epoxy group such as a 3,4-epoxycyclohexyl group.
R ¹ has 4 carbon atoms including these epoxy groups.
To 14 organic groups, which are contained in the silane compound as a monovalent organic group through a Si—C bond. R ² has 1 to 1 carbon atoms such as methyl group, ethyl group, vinyl group, propyl group, octyl group and phenyl group.
4 hydrocarbon groups and substituent derivatives of these hydrocarbon groups. Examples of such a substituent include a halogen group such as a chloro group and a fluoro group, a mercapto group, a cyano group, a (meth) acryloxy group, and an amino group. R ^{2 is} also R ¹
Similarly to, it is a monovalent organic group and is contained in the silane compound through a Si—C bond. X is a hydrolyzable group, such as an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group, a carboxyl group such as an acetoxy group, a halogen group such as a chloro group and a bromo group, a methoxyethoxy group, an ethoxyethoxy group and the like. Examples thereof include an alkoxyalkoxy group, a ketoxime group and a propenyl group. Further, a is 0 or 1 and b is 0, 1
Or 2. Further, (a + b) is 0, 1 or 2
Is. When b is 2, R ² may be the same or different.

Specific examples of the organosilicon compound represented by the general formula (I) include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane,
Vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ
-Chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane Methoxysilane, γ
-Aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxyethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ-
Aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane,
Glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α- Glycidoxypropyltrimethoxysilane,
α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ-glycidoxypropyltrimethoxyethoxysilane, γ-glycidoxypropyltriphenoxysilane, α-glycidoxybutyltrimethoxysilane ,
α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane,
(3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ) Ethyltriethoxysilane, β
-(3,4-Epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxyethoxysilane, β- (3 , 4-Epoxycyclohexyl) ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-
Trialkoxysilanes such as epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ- (3,4-epoxycyclohexyl) butyltriethoxysilane, triacyloxysilane or triphenoxysilane. Or a hydrolyzate thereof and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane,
γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ -Mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-
Aminopropylmethyldiethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxyethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxy Methylmethyldiethoxysilane, β-glycidoxyethylmethyldimethoxysilane, β-glycidoxyethylmethyldiethoxysilane, α-glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β- Glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypro Pyrmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropylmethyldiphenoxylan, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxysilane, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane Examples are silane, dialkoxysilanes such as γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilane or diacyloxysilanes or hydrolysates thereof.

On the other hand, in the compound represented by the general formula (II), which is another preferred silane coupling agent, R ³ and R ⁵ are R in the general formula (I).
An example similar to ¹ can be given. Examples of R ⁴ and R ⁶ are the same as those of R ^{2 in the} general formula (I). Further, as the hydrolyzable group for Q, the same examples as for X in the general formula (I) can be given. Also,
c and e are 0 or 1 respectively, and d and f are 0, 1 or 2 respectively. Furthermore, (c + d), (e
+ F) is 0, 1 or 2, respectively. When d or f is 2, R ⁴ and R ⁶ may be the same or different.

Y is an organic group having 2 to 40 carbon atoms. That is, Y is a functional group contained in the molecule through two Si atoms and a Si—C bond, and the functional group contains a heteroatom other than carbon and hydrogen such as an oxygen atom and a nitrogen atom. There is no problem. Furthermore, within the range of 2 to 40 carbon atoms, the organic group may be chain-like or cyclic, and there is no problem even if an oxygen atom or the like is present as an epoxy ring or the like. In particular, when an oxygen atom or the like is present as an epoxy ring or the like, it is preferable because it contributes as a functional group during curing.

As a specific example of Y,

[Chemical 4] And so on.

Among the organosilicon compounds represented by the above general formula (I) or (II), it is preferable to use an organosilicon compound containing an epoxy group or a glycidoxy group for the purpose of improving low temperature curability and hardness. is there. In addition, from the viewpoint of the curing speed and the ease of hydrolysis, X and Q have 1 to 1 carbon atoms.
4 alkoxy groups or alkoxyalkoxy groups are preferably used.

Among these organosilicon compounds and / or their hydrolysates, hydrolysates are preferred in order to lower the curing temperature and promote crosslinking.

Hydrolysis is produced by adding pure water or an acidic aqueous solution such as hydrochloric acid, acetic acid or sulfuric acid and stirring. Furthermore, the degree of hydrolysis can be easily controlled by adjusting the amount of pure water or acidic aqueous solution added. At the time of hydrolysis, it is particularly preferable to add pure water or an acidic aqueous solution in an amount of at least equimolar and at most 3 times the molar amount of the X group or Q group of the general formula (I) or (II) from the viewpoint of accelerating the curing.

Since alcohol and the like are produced during the hydrolysis, it is possible to perform the hydrolysis without a solvent. However, for the purpose of making the hydrolysis even more uniform, after mixing the organic silicon compound and the solvent, the hydrolysis is performed. It is also possible to disassemble. It is also possible to remove an appropriate amount of alcohol after hydrolysis under heating and / or reduced pressure for use depending on the purpose, and to add an appropriate solvent after that.

Examples of these solvents include alcohols, esters, ethers, ketones, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, and solvents such as N, N-dimethylformamide and dimethylimidazolidinone. Further, these solvents can be used as a mixed solvent of two or more kinds, if necessary. Further, depending on the purpose, it is possible to accelerate the hydrolysis reaction and further heat it to room temperature or higher in order to proceed the reaction such as precondensation, or to lower the hydrolysis temperature to room temperature or lower in order to suppress precondensation. It is also possible to do so.

Further, in the antifogging coating composition of the present invention, a preferable crosslinking agent has an average particle size of 5 to 2
An effective example is silica sol using fine particle silica of 00 mμ. The silica sol is preferably a colloidal dispersion of high molecular weight silicic acid anhydride in a solvent such as water and / or alcohol. For the purpose of the present invention, those having an average particle diameter of about 5 to 200 mμ are preferably used, but those having a diameter of about 7 to 50 mμ are particularly preferable. If the average particle size is less than 5 mμ, the stability of the dispersed state is insufficient, and it tends to be difficult to obtain a product of constant quality, and if it exceeds 200 mμ, the transparency of the formed coating film is poor. There are cases.

The addition ratio of the polyvinyl alcohol and the cross-linking agent in the present invention should be appropriately optimized depending on the desired antifogging property and the substrate to which it is applied. When the heat resistance of the base material is 100 ° C. or higher, polyvinyl alcohol is added in an amount of 5 to 300 with respect to 10 parts by weight of the crosslinking agent component.
It is preferably part by weight. Especially when both high surface hardness and antifogging function are satisfied at the same time, the crosslinking agent component 1
To 0 parts by weight of polyvinyl alcohol 7.5-1
It is preferably used in the range of 50 parts by weight.

Performance can be improved or modified by adding components other than the above components to the film obtained from the antifogging coating composition of the present invention.

For example, it is preferable to add a dye / pigment to the extent that transparency is not impaired, and it is also possible to dye the cured film.

Further, in order to improve weather resistance and adhesion, it is preferable to use various epoxy resins, urethane resins and acrylic resins. Among them, the aliphatic type epoxy resin is particularly preferable because it can greatly improve the improvement effect.

The antifogging coating composition of the present invention comprises
It is preferable to use a polyvinyl alcohol-soluble organic solvent having a boiling point of 105 ° C. or higher and 300 ° C. or lower as the solvent, and the solvent here is capable of dissolving polyvinyl alcohol at a concentration of 1 wt% or higher, and within the above range. It is an organic solvent having a boiling point. When the boiling point is 105 ° C or higher, the smoothness of the resulting coating film is particularly excellent.
When the temperature is 0 ° C. or lower, the resulting coating film is particularly well cured. Here, the term “dissolution” means that it makes polyvinyl alcohol transparent, and includes those having thixotropy. Specific examples of such organic solvents include:
Dialkyl imidazolidinone etc. are mentioned. The dialkyl imidazolidinone has, for example, 1 to 4 carbon atoms.
Having an alkyl group of is preferable, and cymethylimidazolidinone is particularly preferably used because it is easily available.

The antifogging coating composition of the present invention may contain a solvent other than the above-mentioned essential components, additives, various improving agents, etc., but the essential components are the main components. It is preferable that the coating film contains 2% by weight or more.

As the solvent, in addition to the above-mentioned soluble organic solvent, for example, water, various alcohols, ketones, esters, ethers, cyclic ethers, dimethylformamide, dimethylsulfoxide and the like can be appropriately used.

As the additive, various surfactants can be used for the purpose of improving the surface smoothness, and silicone compounds, fluorine-based surfactants, organic surfactants, etc. can be used as examples.

Further, as an improving agent, an organic polymer having good compatibility with the antifogging coating composition of the present invention, for example, hydroxyethyl cellulose, polyhydroxyethyl methacrylate, or a polymer thereof, alcohol-soluble nylon, polyacrylamide, polyvinylpyrrolidone Or the copolymer etc. are mentioned. Furthermore, ethyl silicate, n-propyl silicate, i-propyl silicate, n-butyl silicate, i-butyl silicate,
It is also possible to add a tetrafunctional silane compound such as t-butyl silicate, or an amide resin.

Further various catalysts known in order to promote the curing as required as a condensation and / or reaction catalyst silanol and hydroxyl groups of the silanol is used, represented by the general formula _{Al · X a · Y 3-} a Aluminum chelate compounds can be used particularly preferably (where X is a lower alkoxy group, Y is a ligand derived from a compound selected from the group consisting of M ¹ COCH ₂ COOM ² and M ³ COCH ₂ COOM ⁴ (M ¹ , M ² , M ³ and M ⁴ are lower alkyl groups), and a is 0, 1 or 2.). Various compounds can be used as the aluminum chelate compound, but as a particularly preferable example from the viewpoint of catalytic activity, solubility in the composition, and stability, aluminum acetylacetonate, aluminum ethylacetoacetate bisacetylacetonate, Aluminum bisacetoacetate monoacetylacetonate, aluminum di-
Examples include n-butoxide monoethylacetoacetate and aluminum di-i-propoxide monomethylacetoacetate, and a mixture of these compounds can also be used.

Additives other than the above essential components are used in the present invention such as heat resistance, weather resistance, water resistance, adhesiveness or chemical resistance for the coating film formed from the antifogging coating composition of the present invention. It is possible to improve various practical properties depending on the application to which it is applied.

In order to obtain the antifogging coating composition of the present invention, for example, a method of simply mixing the respective components or a method of mixing the other components with a component which has been previously subjected to treatment such as hydrolysis depending on the components is used. And so on,
All of these are useful methods for producing the composition of the present invention.

The components A and B in the present invention are such that the solid content of the B component is 100 parts by weight of the solid content of the A component.
It is preferably used in the range of 1.0 to 200 parts by weight. If the solid content of the component B is less than 1.0, the water resistance or hardness tends to decrease, and if it exceeds 200 parts by weight, the antifogging property tends to decrease. It is more preferably 3.0 to 150 parts by weight.

The method of applying the antifogging coating composition of the present invention to an object to be coated is generally known in the art, such as brush coating, dip coating, spin coating, flow coating, spray coating, roll coating, curtain flow coating and the like. Various known methods can be used.

The film obtained from the antifogging coating composition of the present invention preferably has a film thickness of 1 μm or more. That is, when it is less than 1 μm, the antifogging effect tends to be poor. On the other hand, the upper limit of the film thickness is not particularly limited, and it can be used as a film or sheet, but it is 500 μm or less from the viewpoint of mechanical properties. It is preferable to use it by coating it on various base materials. Especially,
From the viewpoint of workability, it is preferably 200 μm or less.

As the other surface coating composition of the present invention, there is no problem even if it is blended in the antifogging film, but in order to exert a remarkable antifogging property and a water drop preventing effect, the above antifogging property is used. It is desirable to coat it on the conductive coating.

In the present invention, a film comprising a surface coating composition containing C, D and E components as main components is provided on the film comprising these anti-fogging coating compositions. , Has a good affinity with a film formed of the antifogging coating composition, and can be uniformly coated without surface cissing,
It is important that the adhesiveness is excellent, the water resistance is good, and the durability is excellent.

As such a surface coating composition, a water-soluble or water-dispersible organic anionic compound,
It was found that at least one selected from a specific organosilicon compound and its hydrolyzate was added to a coating composition in which an alumina sol and a silica sol were mixed to satisfy the above requirements.

The alumina sol used in the present invention is preferably water-dispersible, and generally commercially available alumina sol can be used. The average particle size is 10 mμ to 1
Those having a particle size of 00 mμ are preferable, and for example, trade names: Cataloid AS-1, Cataloid AS-2, manufactured by Nissan Kagaku Co., Ltd., alumina sol 200 (trade name), alumina sol 520 (trade name) and the like can be mentioned.

The silica sol used in the present invention is preferably water-dispersible, and an acidic silica sol is preferably used because of its affinity with the alumina sol and the stability of the mixed sol. Further, particles having a positive charge are particularly preferable. The average particle diameter is preferably from 7 mμ to 100 mμ, and commercially available ones can be used. Specific examples are "Cataloid SN" manufactured by Catalyst Kasei Co., Ltd., "Snowtex O" manufactured by Nissan Chemical Co., Ltd., and "Snowtex A".
K "and the like. Particularly, for the purpose of preventing the adhesion of water droplets, among the acidic silica sols, those having a positive particle charge can be more preferably used. The mixing ratio of the mixed colloidal sol is an antifogging film. It is not limited as long as the adhesiveness with is obtained, but more preferably 9/1
Particularly good results can be obtained at a mixing ratio (solids weight ratio) of 2/8 (alumina sol / acidic silica sol).

Specific examples of the organic anionic compound used in the present invention include aliphatic cambonic acids such as butyric acid, caproic acid, lauric acid, caprylic acid and oleic acid, and aromatic carboxylic acids such as p-toluic acid. In addition to alkali metal salts and ammonium salts, there may be mentioned sulfonic acid alkali metal salts and ammonium salts. Examples of sulfonic acids include alkyl sulfonic acids such as methane sulfonic acid, octyl sulfonic acid and dodecyl sulfonic acid. Examples thereof include sulfonic acids having an ester group such as dioctylsulfosuccinic acid and aromatic sulfonic acids such as dodecylbenzenesulfonic acid and p-toluenesulfonic acid. Further, examples thereof include alkali metal salts and ammonium salts of phosphoric acid esters and sulfuric acid esters, and phosphates such as octyl phosphate and lauryl phosphate, and sulfates such as octyl sulfate and lauryl sulfate can be preferably used.

The E component of the present invention is the same organosilicon compound represented by the above general formula (I) or (II) as the crosslinking agent used for the coating of the antifogging coating composition and its hydrolysis. A compound selected from the above is used.

The one or more compounds selected from the organic anionic compound, the organic silicon compound and the hydrolyzate thereof in the present invention are from the viewpoints of adhesion to the coating film comprising the antifogging coating composition, prevention of water droplet adhesion and durability. Therefore, it is preferable to use it in a range not exceeding 100 parts by weight with respect to 100 parts by weight of solids of alumina sol and silica sol. The addition ratio and concentration of both are appropriately optimized depending on the stability of the surface coating composition or the desired surface properties such as static contact angle, surface hardness and adhesion. Furthermore, when applying the coating composition, water or an alcohol, a hydrophilic solvent such as dimethylformamide, etc., are used as appropriate, as long as the coating solution does not become non-uniform,
Can be diluted. It is also preferable to add a catalyst such as an aluminum chelate compound similar to the film made of the antifogging coating composition in order to further strengthen the crosslinking of the surface coating composition and enhance the water resistance. Further, it is more preferable to heat-treat the substrate within a range in which the heat resistance of the substrate is allowed.

As the means for applying the surface coating composition in the present invention, the same application method as for the coating comprising the antifogging coating composition can be used, and it may be varied depending on the shape of the substrate, the coating thickness, the application purpose and the like. The thickness can be selected and is not particularly limited, but a coating thickness of 5 mμ to 500 mμ is particularly suitable for the purpose.

[0048]

EXAMPLES In order to make the effects of the present invention clearer, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 (1) Preparation of γ-glycidoxypropyltrimethoxysilane hydrolyzate 236 g of γ-glycidoxypropyltrimethoxysilane was charged into a reactor equipped with a rotor, and the liquid temperature was 10 ° C. Keep at 0.01 and stirring with magnetic stirrer
54 g of a normal hydrochloric acid aqueous solution was gradually added dropwise. After completion of dropping, cooling was stopped to obtain a hydrolyzate of γ-glycidoxypropyltrimethoxysilane.

(2) Preparation of paint Polyvinyl alcohol (product of Nippon Synthetic Chemical Industry Co., Ltd.,
AL-06, saponification degree 91.0-94.0 mol%) 2
After weighing 532 g of a 7.1% by weight aqueous solution in a beaker, 62.4 g of the γ-glycidoxypropyltrimethoxysilane hydrolyzate, and 1,4-dioxane 107.6 g, and methanol 52.4 g were stirred. , Dimethylimidazolidine 66.63g, aluminum acetylacetone 3.6g as a catalyst, fluorine-based surfactant 0.6
g was mixed and dissolved to obtain a paint.

(3) Formation of anti-fog coating A float glass plate was coated with the coating material prepared in (2) above, and after 20 minutes, it was dried for 2 hours in a hot air dryer at 140 ° C. Then, it was immersed in hot water at 90 ° C. for 1 hour to carry out a wet treatment. Then, it was dried to obtain a glass substrate having an antifogging film. (4) Preparation of surface coating composition Alumina sol (trade name: Cataloid AS- manufactured by Catalyst Kasei Co., Ltd.)
1. Solid concentration 7.5%) was mixed with silica sol (manufactured by Nissan Kagaku Co., Ltd .: Snowtex AK solid concentration 21%) at a mixing ratio of 60 parts / 40 parts in terms of pure content. Subsequently, 20 parts of the hydrolyzate of γ-glycidoxypropyltrimethoxysilane prepared in (1) in terms of pure content was added to prepare a solution A. 3000 parts of water was prepared, the solution A was added using a stirrer, and then, as the solution B, 50 parts of sodium butyrate aqueous solution was added, and the mixture was stirred again.

(5) Formation of surface coating composition The surface coating composition prepared in (4) was uniformly applied onto the antifogging film provided in (3) by a spin coater, and 8
Heat treatment was performed at 0 ° C. for 15 minutes to form a hydrophilic film.

(6) Evaluation The surface-modified antifogging film laminated in the above (3) and (5) was evaluated by the following test method, and the results shown in Table 1 were obtained. The coating film was excellent in antifogging property and prevention of water drop adhesion.

(A) Transparency: Total light transmittance was measured by a color computer manufactured by Suga Test Instruments Co., Ltd.

(B) Adhesion: 100 pieces of crevices reaching the substrate of 1 mm square were put on the surface of the coating with a steel knife, and cellophane adhesive tape was strongly adhered and rapidly peeled in the direction of 90 degrees to confirm the peeled state of the coating. saw.

(C) Anti-fogging property: The film coated on the substrate was held over a constant temperature water bath of 40 ° C. sealed in a room of 23 ° C. and 60% RH, and the time until the surface began to become cloudy was observed.

(D) Static contact angle: Using a CA-D type contact angle meter manufactured by Kyowa Interface Science Co., Ltd., the static contact angle to water was observed by the droplet method.

Examples 2-5, Comparative Examples 1-5 On the anti-fogging coating of Example 1, a composition in which each component of the surface coating composition was changed or a surface coating condition was changed was formed. . The results are shown in Table 1.

[0059]

[Table 1]

[0060]

The antifogging coating of the present invention has the following features.

(1) The antifogging property is excellent and the antifogging effect is maintained.

(2) It has an excellent effect of preventing water droplets from adhering and has good visibility.

(3) Excellent in light transmission.

(4) It has excellent durability such as water resistance.

(5) It has good adhesion to a substrate or the like.

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display area C09D 129/04 PFM 6904-4J

Claims (3)

[Claims] 1. A coating composition obtained by curing a coating composition comprising the following components A and B as main components, and the following C:
A surface-modified antifogging film having a film made of a coating composition containing D and E components as main components. A. Polyvinyl alcohol B. Crosslinking agent C. Alumina sol D. Silica sol E. Water-soluble or water-dispersible organic anionic compound,
At least one compound selected from the organosilicon compounds represented by the following general formula (I) or (II) and hydrolysates thereof. [Chemical 1] (Here, R ¹ , R ³ , and R ⁵ are epoxy-containing organic groups having ^{4 to} 14 carbon atoms, and R ² , R ⁴ , and R ⁶ are 1 to 1 carbon atoms.
4 hydrocarbon group, or a hydrocarbon group having 1 to 14 carbon atoms having a substituent selected from a halogen group, a mercapto group, a cyano group, a (meth) acryloxy group and an amino group, X
And Q represent a hydrolyzable group. a, c and e are 0, 1 or 2, respectively. Furthermore, (a + b), (c +
d) and (e + f) are 0, 1 or 2, respectively.
Y is an organic group having 2 to 40 carbon atoms. ) 2. A cross-linking agent having an average particle size of 5 mμ or more, 200
fine particulate silica having a particle size of mμ or less, the general formula (I) or (I
The surface-modified antifogging film according to claim 1, which is at least one compound selected from the organosilicon compounds represented by I) and a hydrolyzate thereof. 3. C / D (weight ratio) is 9/1 or more, 2/8
The surface-modified according to claim 1, wherein the coating composition containing C, D and E as main components has a static contact angle of water of 50 degrees or less. Anti-fog coating.