JPH08311367A - Resin composition for water repellent coating - Google Patents

Abstract

(57) [Summary] [Purpose] It can be formed by coating, has excellent adhesion to substrates and water repellency, is an organic material with extremely high hardness, is not attacked by acid rain, and has a fluorine content. The resin composition for water-repellent coating is provided at a low cost because it has less amount. [Structure] (A) 20 to 80% by weight of a fluorine-containing monomer having a carbon-carbon unsaturated double bond and a perfluoroalkyl group
By copolymerizing 80 to 20% by weight of a monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group, and 0 to 20% by weight of a monomer having a carbon-carbon double bond and a carboxyl group. And (B) 60 to 98% by weight of a monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group, and 40 a monomer having a carbon-carbon unsaturated double bond and a carboxyl group.
% To 2% by weight of the copolymer, and the proportion of the fluorine-containing monomer in the total composition is 0.1 to 10% by weight.
A resin composition for water-repellent coating, wherein

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a windshield for automobiles, a rear glass, a door glass, a fender mirror, a door mirror and a glass for transportation equipment such as railroads and airplanes.
The present invention relates to a water-repellent coating excellent in adhesion, hardness, acid resistance and the like used for window glass of high-rise building and further for resin plates such as polycarbonate and polyacrylic plates.

[0002]

2. Description of the Related Art A water-repellent coating called a liquid wiper has been rapidly used in the market in recent years in order to repel waterdrops adhering to windshields, door glasses, door mirrors, etc. in rainy days and to secure visibility without using a wiper. It is expanding.
However, since the water-repellent coating film obtained with this liquid wiper has poor durability, water repellency cannot be maintained unless it is applied regularly. In addition, a coating film having high water repellency could not be obtained unless the glass surface was thoroughly washed before coating. Further, although liquid wipers have poor acid resistance, acid rain is now a problem, and automobile materials are also required to have acid rain resistance. In order to solve these problems, various low molecular weight compounds containing fluorine and silicon have been proposed, but in order to obtain sufficient water repellency, the compound must contain a large amount of fluorine. However, since fluorine is expensive, the cost of the material is increased, and since it is necessary to bake at a high temperature for a long time, there is a drawback that productivity is poor. In addition, especially the water repellent coat applied to the windshield,
It was necessary to have high hardness because it is easily rubbed by a wiper and worn, but there was no material having high hardness and high water repellency.

[0003]

The object of the present invention is a polymeric material that is cured at a relatively low temperature, yet has a very high hardness, and is excellent in adhesion to glass, weather resistance, acid resistance and acid rain. Another object of the present invention is to provide an inexpensive resin composition for water-repellent coating, which is not affected by the above and has a low fluorine content. In order to achieve this object, the present inventors determined that it is difficult to achieve both hardness and water repellency with one polymer,
I found a method of mixing two types of polymers, one that expresses hardness and the other that exhibits water repellency.
Even with that method, sufficient hardness could not be obtained.
However, the present inventors have found that the hardness is dramatically improved by copolymerizing a certain kind of monomer, and have completed the present invention.

[0004]

The present invention provides (A) 20 to 80% by weight of a fluorine-containing monomer having a carbon-carbon unsaturated double bond and a perfluoroalkyl group, and a carbon-carbon unsaturated double bond. A polymer obtained by copolymerizing 80 to 20% by weight of a monomer having a hydrolyzable silyl group and 0 to 20% by weight of a monomer having a carbon-carbon double bond and a carboxyl group, (B).
Copolymerized with 60 to 98% by weight of a monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group and 40 to 2% by weight of a monomer having a carbon-carbon unsaturated double bond and a carboxyl group. A water-repellent coating resin composition comprising a polymer and having a ratio of the fluorine-containing monomer in the total composition of 0.1 to 10% by weight.

As an example of the monomer having a perfluoroalkyl group having a carbon-carbon unsaturated double bond used in the component (A) constituting the present invention, 2- (perfluoroisononyl) ethyl methacrylate, 2- ( Perfluorononyl) ethyl methacrylate, 2- (perfluorodecyl) ethyl methacrylate, 2- (perfluorobutyl) ethyl methacrylate, perfluoromethyl-methyl methacrylate,
Perfluoroethyl-methyl methacrylate, perfluorobutyl-methyl methacrylate, perfluorooctyl-methyl methacrylate, perfluorodecyl-methyl methacrylate, perfluoropropyl-propyl methacrylate, perfluorooctyl-propyl methacrylate, perfluorooctyl-amyl methacrylate, per Fluorooctyl-perfluoroalkyl-alkyl methacrylate having a perfluoro group having 1 to 20 carbon atoms such as undecyl methacrylate and perfluoroalkyl-wherein the methacrylate is changed to an acrylate 1.
Alkyl acrylates; such as perfluorobutyl ethylene, perfluorohexyl ethylene, perfluorooctyl ethylene, and perfluorodecyl ethylene are used, and they are used at a copolymerization ratio of 20 to 80% by weight, in order to obtain sufficient water repellency. It is desirable to copolymerize 40% by weight or more.

Examples of the monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group used in the component (A) constituting the present invention include γ-acryloxypropyltrimethoxysilane and γ-methacryloxypropyl. Trimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloyloxypropyldimethylmethoxysilane; trimethoxyvinylsilane, dimethoxymethylvinylsilane, triethoxyvinylsilane,
Examples thereof include triethoxyallyl silane, and the copolymerization ratio is 20 to 80% by weight in order to obtain a practical cured film. The weight average molecular weight of the obtained polymer (A) is in the range of 2000 to 100,000.

Examples of the monomer having a carbon-carbon unsaturated double bond and a carboxyl group used in the component (A) constituting the present invention include acrylic acid, methacrylic acid, crotonic acid,
Itaconic acid, maleic acid, etc. are mentioned, and 0 to 20% by weight
Used in a copolymerization ratio of. As an example of the monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group used in the component (B) constituting the present invention, as described above, γ
-Acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloyloxypropyldimethylmethoxysilane, acryloxymethyltrimethoxysilane, methacryloxymethyltrimethoxysilane; tri Methoxyvinylsilane, dimethoxymethylvinylsilane, triethoxyvinylsilane, triethoxyallylsilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinyltris (2-methoxyethoxy) silane and the like,
It is used in a copolymerization ratio of 60 to 98% by weight.

Acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid and the like are listed as examples of the monomer having a carbon-carbon unsaturated double bond and a carboxylic acid used in the component (B) constituting the present invention. Used in a copolymerization ratio of 2 to 40% by weight. The weight average molecular weight of the obtained polymer (B) is 2000 to 100,000. Of course, the above components may be used alone or in combination of two or more.

Polymerization of the above-mentioned monomer components for producing the copolymer of the present invention can be carried out by a method known per se, for example, solution polymerization, and as a solvent to be used, for example, methanol, ethanol, propanol, Alcohols such as butanol, ethylene glycol methyl ether, diethylene glycol methyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone,
Ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether and diethylene glycol dimethyl ether, hydrocarbons such as hexane, heptane and octane,
Aromatics such as benzene, toluene, xylene, cumene,
It is possible to use esters such as ethyl acetate and butyl acetate. Of course, two or more kinds can be appropriately used together and used as a solvent. Solution concentration of polymer during synthesis is 1
~ 80% by weight.

As the polymerization initiator, a usual peroxide or azo compound, for example, benzoyl peroxide, azoisobutylvaleronitrile, azobisisobutyronitrile, di-t-
Butyl peroxide, t-butyl perbenzoate, t-butyl peroctoate, cumene hydroxyperoxide and the like are used, and the polymerization temperature is 50 to 140 ° C., preferably 70 to 1
40 ° C. To perform coating using the composition of the present invention, doctor blade, bar coater, coating using an applicator, spray coating, spin coating,
Any ordinary coating method such as dip coating can be adopted. Especially when smoothness is required, spin coating is preferably used.

In the present invention, a catalyst that accelerates the crosslinking reaction of the hydrolyzable silyl group in the composition can be used if necessary. Typical examples of the catalyst for hydrolysis and condensation of such hydrolyzable silyl groups are aluminum triacetylacetonate, iron triacetylacetonate, manganese tetraacetylacetonate, nickel tetraacetylacetonate, chromium hexaacetylacetonate, Metal complex compounds such as titanium tetraacetylacetonate and cobalt tetraacetylacetonate; metal alkoxides such as aluminum ethoxide, aluminum propoxide, aluminum butoxide, titanium ethoxide, titanium propoxide, titanium butoxide;

Sodium acetate, tin octylate, lead octylate, cobalt octylate, zinc octylate, calcium octylate, lead naphthenate, cobalt naphthenate, dibutyltin diacetate, dibutyltin dioctate, dibutyltin dilaurate, dibutyltin malate. Metal salt compounds such as formic acid, acetic acid, propionic acid, p-toluenesulfonic acid, trichloroacetic acid, phosphoric acid, monoalkylphosphoric acid, dialkylphosphoric acid, phosphoric acid ester of β-hydroxyethyl (meth) acrylate, monoalkylphosphorous acid Examples thereof include acids and acidic compounds such as dialkylphosphorous acid, and tin compounds such as dibutyltin diacetate dibutyltin dioctate, dibutyltin dilaurate and dibutyltin dimaleate, and p-toluenesulfonic acid are particularly preferable. The amount of this catalyst used is in the range of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on 100% by weight of the resin composition.

[0013]

EXAMPLES Next, examples of the present invention will be described more specifically. In the examples, all parts are parts by weight. Synthesis methods of Examples 1 to 10 and Comparative Example 2 Two four-necked flasks equipped with a cooling pipe, a stirrer, a thermometer, and a nitrogen introduction pipe were prepared, and the components A and B were separately shown in Table 1. Based on the mixing ratio shown, 200 parts of isopropyl alcohol was charged as the solvent, 1.6 parts of azobisisobutyronitrile was heated to 80 ° C. with stirring, and a polymerization reaction was performed for 2 hours. 0.4 parts of ronitrile was added and polymerization was carried out for 2 hours to obtain a polymer solution.

The polymer solution of the component A and the polymer solution of the component B thus obtained were 1:99 in terms of solid content.
Were mixed in the ratio. Only Comparative Example 1 is a single polymer with the same composition as when the two polymers of Example 1 were mixed 1:99. As a crosslinking catalyst, 1% paratoluenesulfonic acid was added to the solid content of the solution, and ethyl acetate was further added to obtain a coating liquid with a solid content of 10%. The thickness of this coating solution is about
It was applied to a 1.3 mm glass plate with a 1 mil applicator and left at room temperature for 30 minutes. Then, it was baked in an oven at 200 ° C. for 10 minutes to obtain a water-repellent coated glass plate.

Various tests were conducted on the water-repellent coated glass plate thus prepared. The test method is as follows. Contact angle: The contact angle of the water-repellent coating film to pure water was measured with a contact angle meter using a contact angle measuring device manufactured by Kyowa Interface Science Co., Ltd. Hardness: Measured at room temperature by a method according to JIS K5400. Acid resistance: The state of the coating film after being immersed in a 5% sulfuric acid solution at room temperature for 4 hours was visually evaluated. The test results are shown in Table 2.

[0016]

[Table 1]

Table 2 ────────────────────────────────── Sample mixing or single contact angle Pencil hardness Acid resistance ────────────────────────────────── Example 1 Mix 112 9H Good Example 2 Mix 111 9H Good Example 3 Mix 108 9H Good Example 4 Mix 109 9H Good Example 5 Mix 102 9H Good Example 6 Mix 112 8H Good Example 7 Mix 110 9H Good Example 8 Mix 109 9H Good Example 9 Mix 107 8H Good Example 10 Mixed 106 8H Good Example 11 Mixed 104 8H Good Comparative Example 1 Single 68 8H Good Comparative Example 2 Mixed 111 6H Good ───────────────────────── ────────── Remark: Mixed is a mixed system of two kinds of polymers, single is only one kind of polymer

[0018]

From the above results, a single polymer has a small contact angle with water and does not exhibit water repellency. Aqueous is improved. Furthermore, by copolymerizing a monomer having a carboxyl group, the altitude is increased from 6H to 9-8.
You can see that it has improved to H. That is, according to the present invention, by adopting a mixture of a polymer having a hydrolyzable silyl group and a perfluoroalkyl group in a side chain and a polymer having a hydrolyzable silyl group and a carboxyl group, only a small amount of fluorine is contained. It has high water repellency even though it is not used, has high hardness despite being an organic material, has excellent adhesion to the base material, and is high in crosslink density, so it is hard and is not attacked by acid rain. An inexpensive water repellent coating film could be obtained.

Claims (2)

[Claims] 1. A fluorine-containing monomer (A) having 20 to 80% by weight of a carbon-carbon unsaturated double bond and a perfluoroalkyl group, a single monomer having a carbon-carbon unsaturated double bond and a hydrolyzable silyl group. Polymer obtained by copolymerizing 80 to 20% by weight of a monomer and 0 to 20% by weight of a monomer having a carbon-carbon double bond and a carboxyl group, (B) a carbon-carbon unsaturated double bond and hydrolyzability Monomer having silyl group 60 to 98% by weight and monomer having carbon-carbon unsaturated double bond and carboxyl group 4
A resin composition for water-repellent coating, comprising a polymer obtained by copolymerizing 0 to 2% by weight, and the proportion of the fluorine-containing monomer in the entire composition is 0.1 to 10% by weight. . 2. A resin composition for water-repellent coating according to claim 1, which contains a hydrolyzable silyl group crosslinking catalyst.