JPH0546394B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a coating composition, and more specifically, the present invention relates to a coating composition that is coated on plastic molded articles, particularly acrylic resin molded articles, without an undercoat and then heated and cured to form an excellent coating composition. Adhesiveness, surface hardness, abrasion resistance, flexibility, chemical resistance, stain resistance, stainability, surface slipperiness,
The present invention relates to a coating composition useful for protecting substrates, which provides a coating with excellent properties such as water repellency and weather resistance, and which is transparent and has an anti-glare effect. [Technical Background of the Invention and Problems Therein] Plastic molded products are useful for making lenses for eyeglasses and optical equipment, window glass for buildings, and trains by taking advantage of their advantages such as lightness, ease of processing, and excellent impact resistance.・
A wide range of applications are being considered, including window glass for transportation vehicles such as automobiles. However, plastic molded products have drawbacks such as being easily scratched and easily eroded by solvents, so they have serious problems in that their transparency and appearance are easily impaired, and their use is limited to a certain extent. Limited. In order to solve these problems, several proposals have been made regarding coating compositions for forming a film on the surface of plastic molded products that has a high density and has excellent solvent resistance. ing. However, conventional coating compositions have problems such as insufficient scratch resistance or poor workability because an undercoating liquid must be used in advance to improve adhesion. Such coating compositions include, for example, tetrafunctional silanes such as ethyl silicate; trifunctional silanes such as methyltrimethoxysilane and vinyltrialkoxysilane and their hydrolyzed condensates; Silane coupling agents such as methoxysilane and γ-aminopropyltrimethoxysilane; silicone resin coating compositions containing various combinations of colloidal silica and organic compound components such as methylolated melamine and polyvinyl alcohol have already been commercialized. It is used in plastic sunglass lenses, etc. However, these coating compositions require a heat curing temperature of 90 to 100°C or higher in order to obtain practically sufficient hardness and adhesion to the object being coated, and depending on the type of plastic substrate, this may be difficult. Since the temperature exceeds the heat deformation temperature, there is a problem in that the performance cannot be fully utilized. As a solution to these problems, a primer liquid is used to improve adhesion to the substrate, and a curing catalyst is added to the coating composition to ensure sufficient hardness even when heated and cured at relatively low temperatures. methods have been adopted. However, in this method, the number of coating treatments is large, resulting in poor workability, and addition of a curing catalyst shortens the pot life of the coating composition. Furthermore, although the resulting film has sufficient hardness, it does not have sufficient adhesion to the base, and due to the influence of the catalyst remaining in the film, heat resistance and weather resistance decrease, and there are problems such as easy cracking. It has points. On the other hand, recently there has been an increasing demand for matte coating compositions in addition to transparent coating compositions. The matte type coating composition is used for applications that require anti-glare effects, such as anti-reflection filters for cathode ray tube displays and light transmitting plates in front of display panels; light bulbs or fluorescent lights for indoor/outdoor certification equipment. to soften the light of protective boards, advertising lights, billboards, etc.
Items that are used for the purpose of giving a high-class appearance; items that require a concealing or shielding effect such as bathroom window glass; and items that require an anti-reflection effect or that can convert a point light source to a surface light source. In terms of what is required. Conventionally used transparent coating compositions have a mirror-like luster on the film surface and have excellent light transmittance. When applied to a display panel or the like, there is a problem in that the sharpness of characters and figures deteriorates. On the other hand, when a plastic molded body or film, etc., which is not coated with a coating composition is used as an antireflection filter for a cathode ray tube display, there is a problem that the surface is easily scratched when a light pen or the like is used. ing. Also, when applied to reflective plates and protective plates of lighting equipment,
Spray-type insecticides may cause discoloration or deformation, and when applied to advertising protection boards or signboards used outdoors, the weather resistance is not sufficient, resulting in yellowing and impaired appearance. It has the following problems. Furthermore, when ground glass is used for windows in bathrooms, etc., it generally has the problem that when the surface of ground glass becomes wet, its light scattering ability decreases, its concealing or shielding effect is impaired, and its shatter resistance is poor. ing. Further, conventionally known processing methods for obtaining a non-glare effect include, for example, a sandblasting method, a surface scratching method, and a method of blending inorganic powder such as silicon dioxide into a coating composition. Furthermore, as a processing method for obtaining an antireflection film, for example, a base film of silicon dioxide is provided on the plastic surface, and thin films of two or more metal oxides having different refractive indexes are laminated to a constant thickness on top of the base film of silicon dioxide. A method of forming a multi-interference film by, for example, a vacuum evaporation method, a sputtering method, or a high frequency ion plating method is known. However, among the above methods, sandblasting and surface scratching only roughen the surface precision of materials such as glass and plastic, and do not solve the above-mentioned problems. further required. In addition, the method of blending inorganic powder such as silicon dioxide into the coating composition has problems such as poor stability of the composition due to agglomeration and sedimentation of the powder, and difficulty in obtaining a uniform or fixed appearance with good reproducibility. There are problems in handling and work, such as difficulty in handling. Furthermore, the method of forming a thin film of metal oxide requires a large amount of equipment and is not yet suitable for general use. The problem is that it is difficult to form. [Object of the Invention] The object of the present invention is to solve the above-mentioned problems, and to provide a material that has excellent adhesion to the substrate when applied to a substrate such as a plastic molded article, especially an acrylic resin molded article, and which can be obtained. The object of the present invention is to provide a coating composition whose film has transparency and anti-glare effects, and has excellent abrasion resistance, flexibility, chemical resistance, water repellency, and weather resistance. [Summary of the Invention] The coating composition of the present invention has the general formula []: R ¹ Si(OH) ₃ [wherein R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group]. ] A dispersion of organotrihydroxysilane and its partial condensate and colloidal silica, and (A) general formula []: [wherein R ² is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted n-valent aliphatic hydrocarbon residue, and a substituted n-valent aliphatic hydrocarbon residue having at least one ether bond] R ³ represents a hydrogen atom or a lower alkyl group, and n is an integer of 1 to 4. ] At least one radically polymerizable acrylate monomer represented by (B) general formula []: [In the formula, R ⁴ is a monovalent hydrocarbon group, R ⁵ is a divalent hydrocarbon group, and R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group. ], the silicone-modified acrylic resin is comprised of a copolymer with at least one acryloxy-functional silane represented by It is characterized by containing. In the following, the invention will be explained in more detail. The organotrihydroxysilane represented by the general formula [] used in the present invention has the following formula: R ¹ Si(OR') ₃ (wherein, R' represents a monovalent alkyl group, and R ¹ is as defined above). It can be obtained by hydrolyzing the organotrialkoxysilane shown in (same meaning). Examples of such organotrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and γ-trimethoxysilane.
-Aminopropyltriethoxysilane, 3,3,
3-trifluoropropyltrimethoxysilane,
Examples include γ-mercaptopropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane. Examples of the organotrihydroxysilane used in the present invention include those in which the alkoxy group of the above-mentioned organoalkoxysilane is substituted with a hydroxy group. The dispersion of organotrihydroxysilane and its partial condensate and colloidal silica used in the present invention is prepared by stirring and suspending at least one of these organotrialkoxysilanes in colloidal silica, for example, acid or aluminum. It can be prepared by mild hydrolysis in a temperature range of 20 to 40°C using a chelate or the like as a catalyst. This dispersion is
Since the stability is poor as it is, for example, after diluting with an alcohol-based and/or glycol ether-based solvent, water in the system, methanol, a hydrolysis by-product, and Remove low boiling point alcohols such as ethanol from the system. Then, it is preferable to dilute the dispersion liquid again so that the solid content of the dispersion liquid becomes 10 to 40% by weight, and then store it. In order to obtain the surface hardness required for the coating composition, in the above dispersion,
It is preferable that the silica content derived from colloidal silica is contained in an amount of 10 to 90% by weight based on the total amount of solid content, and the remainder is organotrihydroxysilane and its partial condensate. Further, it is more preferable that at least 60 mol% of the organotrihydroxysilane is methyltrihydroxysilane. Solvents used to dilute the dispersion include:
Isopropyl alcohol, isobutyl alcohol, acetic acid ethylene glycol monoethyl ether, and the like are preferred. Examples of the radically polymerizable acrylate monomer represented by the general formula [] include acrylic acid,
Methacrylic acid, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate , isobutyl methacrylate, t-butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-ethylhexyl methacrylate, methoxydiethylene glycol acrylate, Monoacrylate monomers such as methoxydiethylene glycol methacrylate, methoxytetraethylene methacrylate and allyl methacrylate; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, 2, 2-bis(4-methacryloxydiethoxyphenyl)propane, polyethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate and 2,2-bis(4-
diacrylate monomers such as acryloxypropoxyphenyl)propane; triacrylate monomers such as trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, tetramethylolmethane triacrylate; and tetra Examples include tetraacrylate monomers such as methylolmethanetetraacrylate, and one or more monomers selected from the group consisting of these monomers are used. Examples of the acryloxy-functional silane represented by the general formula [] include γ-methacryloxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, and γ-methacryloxysilane. Examples include propyltriisopropoxysilane, and one or more selected from the group consisting of these are used. Among these, it is preferable to use γ-methacryloxypropyltrimethoxysilane because it is easily available. The silicone-modified acrylic resin of the present invention can be obtained by copolymerizing at least one of the above acrylate monomers and at least one acryloxy-functional silane in a suitable solvent using a radical polymerization initiator. It is possible. Copolymerization is preferably carried out by solvent polymerization in a solvent such as alcohol and/or ester for the purpose of suppressing the degree of polymerization, and the polymer obtained in this way can be easily blended with a dispersion. . Further, in the present invention, the above monomer may be copolymerized with a monomer such as acrylonitrile or methacrylonitrile. Examples of the radical polymerization initiator include organic peroxides; benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-t
-butyl peroxide, 2,5-di(peroxybenzoate)hexyne-3,1,3-bis(t
-butylperoxyisopropyl)benzene, lauroylperoxide, t-butylperacetate, t-butylperbenzoate, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 2,5-dimethyl-2 ,5-di(t-
Examples include perester compounds such as butylperoxy)hexane; and azo compounds such as azobisisobutyronitrile (hereinafter referred to as AIBN) and dimethyl azobutyrate. The amount of radical polymerization initiator is based on the total amount of monomers.
It is preferably added in an amount of 0.01 to 0.5% by weight, more preferably 0.05 to 0.2% by weight. When the amount of the radical polymerization initiator added is less than 0.01% by weight, the molecular weight of the copolymer becomes high, and mixing with the dispersion liquid may become difficult. On the other hand, even when added in an amount exceeding 0.5% by weight, the degree of polymerization of the copolymer does not decrease, and when the obtained silicone-modified acrylic resin and dispersion are mixed and coated, the cured film and the plastic substrate, especially the acrylic Adhesion to resin molded products also does not improve beyond a certain value. The composition of the silicone-modified acrylic resin is preferably 70 to 98 mol% of radically polymerizable acrylate monomer, and the remainder is acryloxy-functional silane. If the amount of the acryloxy-functional silane is less than 2 mol %, the copolymerization product may have poor compatibility with the solid content of the dispersion, making it difficult to obtain a transparent film. or,
If it exceeds 30 mol%, scratch resistance will decrease. Further, it is preferable that at least 80 mol% of the radically polymerizable acrylate monomers is a monoacrylate monomer, and further, that at least 50 mol% of the monoacrylate monomers is a methacrylic ester and/or an acrylic ester. preferable. If the monoacrylate monomer is less than 80 mol % of the radically polymerizable acrylate monomers, the resulting copolymer may have poor compatibility with the dispersion and may separate and precipitate. Furthermore, if the amount of methacrylic ester and/or acrylic ester in the monoacrylate is less than 50 mol %, the copolymer is likely to gel, making it difficult to control the reaction. As such methacrylic ester and/or acrylic ester, it is particularly preferable to use methyl methacrylate in order to improve the adhesion of the film. The silicone-modified acrylic resin obtained as described above can be stored in a stable state by diluting it with an appropriate solvent and adding a polymerization inhibitor or the like as necessary. The coating composition of the present invention includes a dispersion of the organotrihydroxysilane and its partial condensate and colloidal silica, and a silicone-modified acrylic resin, in proportion to the total solid content of the dispersion. If the purpose is to form a transparent film, 0.1% by weight or more,
It is blended so that it is less than 10% by weight. If the solid content of the silicone-modified acrylic resin is less than 0.1% by weight, good adhesion to the object to be coated cannot be obtained.
On the other hand, when the purpose is to form a film having an anti-glare effect, it is blended in an amount of 10 to 50% by weight, more preferably 10 to 40% by weight. Within this range, various degrees of anti-glare effect can be selected. If it exceeds 50% by weight, the dispersibility of the solid content and the hardness of the cured product will decrease, which is not preferable. Further, the coating composition of the present invention is preferably prepared so that the solid content of the composition is 15 to 30% by weight in order to ensure workability during application and film thickness. Furthermore, an ultraviolet absorber, a leveling agent, a curing catalyst, etc. may be added to the coating composition of the present invention, if necessary. When applying the coating composition of the present invention to an object made of acrylic resin or the like, it is coated without a special undercoat, and after air-drying at 70 to 80°C.
By heating for 2 to 3 hours, it is possible to obtain a film having excellent adhesion to the object to be coated. Furthermore, when the coating composition of the present invention is used in applications requiring anti-glare effects, it may be applied to a polycarbonate resin molded product without a special undercoat and heated at 100 to 120°C for 1 to 2 hours. It is also possible to obtain a film having excellent adhesion to the object to be coated. [Effects of the Invention] According to the coating composition of the present invention, excellent adhesion to the object to be coated can be achieved by coating a plastic molded article, especially an acrylic resin molded article, without an undercoat and then heating and curing it. It also has excellent performance such as surface hardness, abrasion resistance, flexibility, chemical resistance, stain resistance, stainability, surface slipperiness, water repellency, and weather resistance, and has transparency and anti-glare effects. , coatings useful for protecting substrates are provided. EXAMPLES The present invention will be explained in more detail with reference to Examples below, but these are not intended to limit the present invention in any way. In the examples, parts represent parts by weight. [Examples of the invention] Preparation example 1 Preparation of dispersion 32 parts of methyltriethoxysilane, colloidal silica (trade name: Snowtex; manufactured by Nissan Chemical Co., Ltd.)
Put 40 parts and 0.2 parts of acetic anhydride into a flask, and
The alkoxysilane was hydrolyzed by stirring for 24 hours while controlling the temperature at 30°C. To this reaction solution, 30 parts of isobutyl alcohol was added, and azeotropic stripping was performed at a temperature of 20 to 40°C under a reduced pressure of 20 to 70 mmHg to remove excess water contained in the hydrolysis byproduct ethanol and colloidal silica. Removed. Next, a mixed solvent of isopropyl alcohol, isobutyl alcohol, and acetic acid ethylene glycol monoethyl ether in a weight ratio of 1:5:1 was added, and the mixture was diluted to a solid content of 30% by weight to obtain a dispersion. Preparation Example 2 Preparation of silicone-modified acrylic resin Various methacrylic esters and optionally methacrylic acid or acrylonitrile are mixed with γ-methacryloxypropyltrimethoxysilane (trade name: A-174; Japan (manufactured by Unicar Inc.) was copolymerized in a mixed solution of isopropyl alcohol and ethyl acetate in a weight ratio of 1:1 using AIBN as a polymerization initiator. This reaction solution was diluted with ethylene glycol monoethyl ether acetate, and 7 types (sample number A-1) were diluted with ethylene glycol monoethyl ether acetate.
~A-7) silicone-modified acrylic resins were obtained. In the table, sample number A-8 is a comparative sample that does not contain silicone.

[Table] Example 1 Using the dispersions obtained in Preparation Examples 1 and 2 and the silicone-modified acrylic resin, the solid content of the silicone-modified acrylic resin was determined based on 100 parts of the solid content of the dispersion.
They were blended in the amounts (parts) shown in Table 2 and diluted with a mixed solvent of isobutyl alcohol and ethylene glycol monoethyl ether acetate in a weight ratio of 9:1 so that the total solid content was 23% by weight. Furthermore, 1.0% by weight of 2,4-dihydroxybenzophenone was added as an ultraviolet absorber, and polyoxyalkylene-modified silicone oil was added as a leveling agent.
0.1% by weight was added and mixed to obtain coating compositions 1 to 9 according to the present invention. These formulations are the second
Shown in the table. Comparative Example 1 Comparative coating composition 10 was obtained in the same manner as in Example 3, except that the dispersion obtained in Preparation Example 1 and the comparative acrylic resin (sample number A-8) obtained in Example 2 were used. . Comparative Example 2 Comparative coating composition 11 was obtained in the same manner as in Example 1 except that the silicone-modified acrylic resin was not used.

[Table] Example 2 The coating composition obtained in Example 1 and Comparative Examples 1 and 2 was flow-coated onto an acrylic resin molded plate (trade name: Acrypet VH; manufactured by Mitsubishi Rayon Co., Ltd.) that had been degreased and cleaned with isopropyl alcohol. 23
After air drying for 30 to 40 minutes in clean air with controlled temperature and humidity at ~25℃ and 35 to 45% RH, heat treatment is performed at 80℃ for 2 hours in a hot air circulation constant temperature oven to form a cured film. Obtained. Using this coated plate as a test plate,
The following coating film performance tests were conducted. The results are shown in Table 3. However, heat resistance is determined by applying a primer (product name: PH91; manufactured by Toshiba Silicone Co., Ltd.) on a polycarbonate plate (product name: Lexan Sheet; manufactured by General Electric Company), and then flow-coating it.
A test plate obtained by heating and curing at 120°C for 1 hour was used. Appearance of film: Visual test. A smooth, transparent film with no cracks, cloudiness, or discoloration is considered good. Adhesion of the film to the object to be coated: base tape peel test. JIS D-0202. Made of wear-resistant coating...Uses standard wear wheels CS-10.
The haze value was measured after 200 rotations with a load of 500g using a rotary abrasser (manufactured by Toyo Seiki Co., Ltd.). Pencil hardness...JIS K-5400. Total light transmittance: The total light transmittance of the test plate was measured. Chemical resistance...After immersion in 0.1M nitric acid and 0.1M sodium hydroxide at room temperature for 24 hours,
A case where there is no abnormality in the coating film is considered good. Solvent resistance...Acetone, ethanol, benzine, thinner, toluene at room temperature, 24
A case where there is no abnormality in the coating film after immersion for a period of time is considered good. Heat resistance: Good if there is no abnormality in the coating after being left at 120℃ for 240 hours. Water resistance: Good if there is no abnormality in the coating after 240 hours of immersion in 70℃ warm water. Weather resistance: Accelerated weather resistance test was carried out in a carbon arc sunshine weather meter, 1500
A case where there is no abnormality on the coating film after a certain period of time is considered good.

【table】

[Table] As is clear from Table 3, the cured film obtained from the coating composition of the present invention has excellent adhesion to the acrylic resin molded plate and has excellent wear resistance and weather resistance compared to conventional products. was confirmed to have improved. It was also confirmed that other coating film performances were equivalent or better than those of conventional coating compositions. Furthermore, the cured film of the coating composition according to the present invention has improved flexibility and dyeability with polyester disperse dyes and the like. Furthermore, by adding a silicone-modified acrylic resin to the coating composition of the present invention, the aging process for developing coating film performance, which was conventionally required for silicone coating agents used for this purpose, can be omitted. It is possible to do so. The coating composition of the present invention can be applied to plastic molded products other than acrylic resin, wood products, metal products (including plated products), and others. Example 3 Using the dispersion obtained in Preparation Example 1 and the silicone-modified acrylic resins A-1 to A-3 obtained in Preparation Example 2, the solid content of the silicone-modified acrylic resin was determined based on 100 parts of the solid content of the dispersion. , the parts shown in Table 4 were blended, and the weight ratio of diacetone alcohol and ethylene glycol monoethyl ether acetate was 9:9 so that the total solid content was 23% by weight.
It was diluted with a mixed solvent of 1. Furthermore, 1.0% of 2,4-dihydroxybenzophenone was added as a UV absorber.
% by weight and 0.1% by weight of polyoxyalkylene-modified silicone oil as a leveling agent were added and mixed to obtain coating compositions 12 to 16 according to the present invention. Using these coating compositions,
The coating performance was evaluated in the same manner as in Example 2. The results are shown in Table 4. Note that instead of the abrasion resistance and total light transmittance in Example 2, scratch resistance, transparency, and resolution were measured under the following conditions. Scratch resistance... Scratch test with steel wool #0000. (Evaluation method) A: No damage even if rubbed strongly. B: If you rub it too hard, it will get a little scratched. C: Easily scratched by rubbing. Transparency...The transmittance is measured using a spectrophotometer.
The average value of the transmittance in the range of 400 to 700 nm (visible region) was defined as the transparency. Resolution: The readability of characters when a painted board is placed on a cathode ray tube display.

[Table] Example 4 Using the dispersions and silicone-modified acrylic resins obtained in Preparation Examples 1 and 2, the solid content of the silicone-modified acrylic resin was determined based on 100 parts of the solid content of the dispersion.
They were blended in the amounts (parts) shown in Table 5 and diluted with a mixed solvent of isobutyl alcohol and ethylene glycol monoethyl ether acetate in a weight ratio of 9:1 so that the total solid content was 23% by weight. Furthermore, 1.0% by weight of 2,4-dihydroxybenzophenone as an ultraviolet absorber and polyoxyalkylene-modified silicone oil as a leveling agent.
0.1% by weight was added and mixed to obtain coating compositions 14 and 17 to 23 according to the present invention. These formulations are shown in Table 5.

[Table] Example 5 γ-Glycidoxypropyltrimethoxy was deposited on a cast polymer plate of allyl diglycol carbonate (monomer product name: CR-39; manufactured by Pittsburgh Plate Glass Company) that had been degreased and washed with isopropyl alcohol. After applying the mixture of silane and γ-ureidopropyltriethoxysilane (2:1), the coating compositions obtained in Examples 1 and 4 and Comparative Example 2 were flow-coated and heat-treated at 100°C for 2 hours. A cured film was obtained. Using these coated plates as test plates, the following dyeability test was conducted.
The results are shown in Table 6. Dyeability test: Hot water 1 at 92 to 93°C was placed in a beaker, and 90 c.c. of a staining agent (trade name: Brown H; manufactured by Nippon Kogaku Kogyo Co., Ltd.) was dissolved therein to prepare a staining solution. Apply this staining solution on a hot plate.
The above test plate was heated for 5 to 30 minutes while maintaining the temperature at 92 to 93℃.
After soaking for a minute, the degree of dyeing density was visually checked.

【table】

[Table] Example 6 Using the dispersion obtained in Preparation Example 1 and the silicone-modified acrylic resins A-1 to A-3 obtained in Preparation Example 2, the solid content of the silicone-modified acrylic resin was 100% of the solid content of the dispersion. parts, and the parts shown in Table 7, and the weight ratio of diacetone alcohol and ethylene glycol monoethyl ether acetate was 9:9 so that the total solid content was 20% by weight.
It was diluted with a mixed solvent of 1. Furthermore, 0.8% of 2,4-dihydroxybenzophenone was added as a UV absorber.
% by weight and 1.0% by weight of polyoxyalkylene-modified silicone oil as a leveling agent were added and mixed to obtain coating compositions 24 to 29 according to the present invention. The coating composition obtained as described above was flow-coated without undercoating onto a polycarbonate board (product name: Lexan Sheet; manufactured by General Electric Company) that had been degreased and washed with isopropyl alcohol, and was heated at 23 to 25°C at 35°C. After air drying for 30 minutes in clean air with controlled temperature and humidity at ~45% RH, dry at 120℃ for 1 hour in a hot air circulation thermostat.
A cured film was obtained by heat treatment for a period of time. Using this coated plate as a test plate, the following coating film performance test was conducted. The results are also listed in Table 7. All tests other than the boiling water resistance test were conducted in Example 2 or 3.
It was carried out under the same conditions. Boiling water resistance test of film...Place the test plate in boiling water for 2
After soaking for an hour, taking out and washing with water, wipe off moisture, leave to stand for 1 hour, and check the appearance and adhesion to the coated object in the same manner as in Example 2. If there are no abnormalities, it is evaluated as good.

[Table] * A slight amount of powder was deposited on the surface.
As is clear from the above results, the coating composition of the present invention has excellent adhesion to the object to be coated, and also has good surface hardness, abrasion resistance, flexibility, chemical resistance, and stain resistance. It was confirmed that the coating had excellent properties such as dyeability, surface slipperiness, water repellency, and weather resistance, and was furthermore capable of providing a film having a transparent or anti-glare effect.

Claims (1)

[Claims] 1 General formula []: R ¹ Si(OH) ₃ [wherein R ¹ represents a substituted or unsubstituted monovalent hydrocarbon group]. ] A dispersion of organotrihydroxysilane and its partial condensate and colloidal silica, and (A) general formula []: [wherein R ² is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted n-valent aliphatic hydrocarbon residue, and a substituted n-valent aliphatic hydrocarbon residue having at least one ether bond] R ³ represents a hydrogen atom or a lower alkyl group, and n is an integer of 1 to 4. ] At least one radically polymerizable acrylate monomer represented by (B) general formula []: [In the formula, R ⁴ is a monovalent hydrocarbon group, R ⁵ is a divalent hydrocarbon group, and R ⁶ represents a hydrogen atom or a monovalent hydrocarbon group. ], the silicone-modified acrylic resin is comprised of a copolymer with at least one acryloxy-functional silane represented by A coating composition comprising: 2. The coating composition according to claim 1, wherein at least 50 mol% of (A) is a methacrylic ester and/or an acrylic ester. 3. The coating composition according to claim 2, wherein (A) is methyl methacrylate. 4 Add acrylicoxy-functional silane (B) of silicone-modified acrylic resin to 2% of the total amount of (A) and (B).
The coating composition according to claim 1, containing ~30 mol%. 5. The coating composition according to claim 1, which contains silicone-modified acrylic resin in an amount of 0.1% by weight or more and less than 10% by weight based on the total solid content of the dispersion, and provides a transparent film. 6. The coating composition according to claim 1, which contains a silicone-modified acrylic resin in an amount of 10 to 50% by weight based on the total solid content of the dispersion, and provides a film having an anti-glare effect and dyeability.