JPH0120195B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a coating composition that improves the surface conditions of plastic, wood products, metal products, etc., such as surface hardness, weather resistance, chemical resistance, and dyeing resistance. Plastic moldings such as polycarbonate, polymethyl methacrylate, polystyrene,
Polyvinyl chloride and other materials have excellent transparency, lightness, ease of processing, and impact resistance, but they have poor abrasion resistance and solvent resistance, and their surfaces are easily scratched and easily attacked by organic solvents. There is a drawback. Although methods of coating with various curable resins have been proposed as a method to improve these drawbacks, at present no fully satisfactory method has been obtained. For example, trialkoxysilanes such as methyltrialkoxysilane and phenyltrialkoxysilane, combinations of these with tetraalkoxysilanes such as ethylsilicate and butylsilicate, or mixtures with other resin paints are known. It has not been possible to obtain a coating that has good physical properties such as abrasion resistance, hot water resistance, heat resistance, adhesion, and paint pot life. Also, JP-A-51-42752,
Japanese Patent Publications No. 52-13818 and No. 53-15743 describe the use of epoxy group-containing alkoxysilanes with Lewis acids such as BF ₃ and BF ₃ etherate, or their complexes, HCl, HBr, HI,
Brønsted acids such as HNO ₃ , HClO ₄ , H ₃ PO ₄ ,
The use of metal salts of organic acids such as cobalt naphthenate and zinc naphthenate as curing catalysts has been disclosed, but these are not practical because the pot life of the paint is short or curing takes a long time. JP-A-49-117529 discloses a composition containing an epoxy group-containing alkoxysilane and a zinc borofluoride, tin borofluoride, or boron trifluoride amine complex, but these compositions are not applicable to the methods taught in the disclosure. In this case, sufficient hardness cannot be obtained and the hardness decreases after the hot water test. JP-A-53-111336 describes one or more compounds selected from compounds containing epoxy groups and/or silanol and/or siloxane groups, silica fine particles of 1 to 100 millimicrons, and aluminum chelate compounds. However, the hardness of these cured coatings is insufficient and the hardness decreases when immersed in boiling water. 39) and bisphenol type polycarbonate. Furthermore, when these surface coating treatments are applied to plastic eyeglass lenses, it is desirable that the coating film formed can be easily dyed, but in general, coating films with high surface hardness have poor dyeability and are usually difficult to dye, such as fibers or other materials. The dyeing method used for plastics, etc.
It may not be dyed at all, or even if it is dyed, the harsh conditions during dyeing will cause a decrease in coating performance, such as a decrease in the hardness of the coating. U.S. Pat. No. 4,173,490 discloses that the main component is a cohydrolyzate of ethyl silicate and alkyltrialkoxysilane and/or dialkyldialkoxysilane, and a siloxane or nonionic interface having an active polar group to make it dyeable. Coating compositions containing activators have been disclosed, but the cured coatings tend to crack easily and are poorly colored. Based on the above, the inventors of the present invention have removed these drawbacks and improved wear resistance, hot water resistance, adhesion, weather resistance,
The present invention was developed as a result of repeated research into coating compositions that have good dyeability and a long paint pot life. The present invention is a coating composition containing the following (A), (B) and (C). That is, the present invention relates to (A) (b) an epoxy compound, provided that the general formula

[Formula] (In the formula, R ⁵ is an organic group having an epoxy group,
R ⁶ is hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group, R ⁷ is a hydrocarbon group having 1 to 5 carbon atoms,
an alkoxyalkyl group or an acyl group having 1 to 4 carbon atoms, b is 1 to 3, c is 0 to 2, and b+c≦3. ) Excluding the hydrolyzate of a silicon compound having an epoxy group represented by (b) General formula

[Formula] (In the formula, R ³ and R ⁴ are each independently a hydrogen atom,
It represents a lower alkyl group or a carboxyl group, and X represents a side chain having an epoxy group. ) A coating composition containing at least one polymer or copolymer selected from the group consisting of (B) colloidal silica having a particle size of 1 to 100 millimicrons (C) ammonium perchlorate. Among the component (A) used in the present invention, the epoxy compounds include the following. That is, polyhydric phenols such as bisphenol A, bisphenol F, resorcinol and novolak resin, or ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerin, diglycerol, neopentyl glycol, trimethylolpropane, pentaerythol, and sorbitol. Polyglycidyl ethers obtained from polyhydric alcohols such as and epichlorohydrin; polyglycidyl esters obtained from epichlorohydrin and polybasic acids such as wataric acid, hexahydrophthalic acid and dimer acid; aniline, toluidine, 4,4'-diaminodiphenyl Polyglycidylamines obtained from amines such as methane and isocyanuric acid and epichlorohydrin; and cycloaliphatic epoxy resins such as cyclopentadiene dioxide and cyclohexene oxide. These compounds are 1
You may use one species or a combination of two or more species. Among component (A), the polymer or copolymer having a repeating structural unit represented by the general formula (2) is obtained by polymerizing or copolymerizing a vinyl monomer having at least one epoxy group in the molecule as exemplified below. It can be obtained by Specific examples of vinyl monomers having an epoxy group include glycidyl methacrylate and acrylate, β-glycidoxyethyl methacrylate and acrylate, 3,4-epoxybutyl methacrylate and acrylate, 4,5-epoxypentyl methacrylate and acrylate, allyl Examples include glycidyl ether. In addition to homopolymers or copolymers of these vinyl monomers having epoxy groups, it may also be copolymers of vinyl monomers having epoxy groups and other monomers copolymerizable therewith. That is, other vinyl monomers such as methacrylic acid and acrylic esters such as methyl methacrylate and acrylate, ethyl methacrylate and acrylate, butyl methacrylate and acrylate, hydroxyethyl methacrylate and acrylate, diethylene glycol monomethacrylate and acrylate, methacrylic acid and acrylic General polymerizable vinyl monomers such as acid, styrene, and vinyl acetate can be used as the other monomer. However, if the proportion of repeating structural units represented by the general formula (2) contained in these copolymers becomes too small, the abrasion resistance of the coating film will decrease.
It is preferable to contain the structural unit represented by 20% by weight or more, more preferably 30% by weight or more. From the viewpoint of manufacturing these polymers, if we try to polymerize only vinyl monomers with epoxy groups, they tend to gel due to self-crosslinking. It is preferred to copolymerize with other possible monomers. These polymers or copolymers may be used alone or in combination of two or more. The component (B) colloidal silica having a particle size of 1 to 100 millimeters is a colloidal solution in which ultrafine particles of silicic anhydride having the above particle size are dispersed in a dispersion medium such as water or an alcohol-based dispersion medium. It is manufactured and commercially available. By combining one or more of component (A) with colloidal silica of component (B) and further using ammonium perchlorate (described below) as a curing catalyst, the pot life of the paint is long, and the paint has good abrasion resistance and hot water resistance. , a coating film with good adhesion, weather resistance, dyeability, etc. is formed. In the present invention, the preferred range of the mixing amount of component (A) and component (B) is a total of 25 to 300 parts by weight of component (A) per 100 parts by weight of component (B) (solid content calculated as SiO ₂ ). parts (calculated based on solid content), more preferably
40 to 200 parts by weight. If the total amount of component (A) is less than 25 parts by weight, the effect of the combined use will be reduced, causing problems with film forming properties, adhesion, hot water resistance, dyeing properties, etc., and if it exceeds 300 parts by weight, wear resistance will be reduced. properties, weather resistance, etc. tend to deteriorate. Next, the curing catalyst of ammonium perchlorate, which is component (C) of the composition of the present invention, will be described in detail. That is, the following catalysts are well known as curing catalysts for epoxy groups and/or silanol groups. Namely, perchloric acid, hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, sulfonic acid, para-toluenesulfonic acid, boron trifluoride and its complexes with electron donors.
Lewis acids such as SnCl ₄ , ZnCl ₂ , FeCl ₃ , AlCl ₃ , SbCl ₅ , TiCl ₄ and their complexes. Organic acid metal salts such as sodium acetate, zinc naphthenate, cobalt naphthenate, zinc octylate, and tin octylate. Boufurated metal salts such as zinc borofluoride and tin borofluoride. Boric acid organic esters such as ethyl borate and methyl borate. Alkali such as sodium hydroxide and potassium hydroxide. Titanate esters such as tetrabutoxytitanium and tetraisopropoxytitanium. Metal acetylacetonates such as chromium acetylacetonate, titanyl acetylacetonate, aluminum acetylacetonate, cobalt acetylacetonate, and nickel acetylacetonate. There are amines such as n-butylamine, di-n-butylamine, tri-n-butylamine, guanidine, biguanide, and imidazole, but all of them have various drawbacks. That is, since perchloric acid is an overt catalyst, the pot life of the coating liquid is extremely short. Further, the coloring of the cured coating film is also significant. Hydrochloric acid, para-toluenesulfonic acid,
Brønsted acid or its complex with an electron donor, such as boron trifluoride monoethylamine complex. Lewis acids such as SnCl ₄ and ZnCl ₂ . Sodium acetate, zinc naphthenate, cobalt naphthenate,
Metal salts of organic acids such as zinc octylate and tin octylate. Alkali such as sodium hydroxide and potassium hydroxide; titanate esters such as tetrabutoxytitanium and tetraisopropoxytitanium. Chromium acetylacetonate. n-butylamine, di-n-butylamine, tri-n-butylamine,
Amines such as imidazole require heating at high temperatures for a long period of time in order to cause sufficient curing, which is not practical. Coatings using zinc borofluoride, tin borofluoride, etc. have insufficient water resistance and decrease in hardness when immersed in hot water, and aluminum acetylacetonate has insufficient hardness and does not bond well with the substrate. Adhesion is poor. Based on the above points, the present inventors discovered that ammonium perchlorate, which is a type of latent catalyst, has a long pot life for coating liquids, is sufficiently cured in a short time even at relatively low temperatures, and has good adhesion. was found to be optimal. The amount of this curing catalyst added is based on the solid content [component (A) + component (B)] of the composition.
The amount is 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight. Examples of solvents that may be included in the coating composition include alcohols, kentones, esters, ethers, cellosolves, halides, carboxylic acids, aromatic compounds, and one or two of these. It can be used as a mixed solvent of the above. Especially lower alcohols such as methanol, ethanol, propanol, isopropanol, butanol. Cellosolves such as methyl cellosolve, ethyl cellosolve, butyl cellosolve. Lower alkyl carboxylic acids such as formic acid, acetic acid, and propionic acid. Aromatic compounds such as toluene and xylene. It is preferable to use esters such as ethyl acetate and butyl acetate alone or as a mixed solvent. Furthermore, if necessary, a flow control agent made of a block copolymer of alkylene oxide and dimethylsiloxane, such as NUC Silicone Y-7006 (trade name) manufactured by Nippon Unicar Co., Ltd., can be added to obtain a smooth coating film. The amount of these flow control agents added is sufficient in a small amount, and is 0.01 to 5 parts by weight, more preferably 0.03 to 3 parts by weight, based on the entire coating composition. Further, small amounts of antioxidants, ultraviolet absorbers, etc. can also be added. After coating with the composition of the present invention by a commonly used coating method such as dipping, spraying, roller coating, or flow coating, By baking and curing for 20 minutes to 5 hours, a coating film with good abrasion resistance, hot water resistance, adhesion and weather resistance can be obtained. The preferred thickness of this coating is 1 to 30 microns.
More preferably, it is 3 to 15 microns. If it is less than 1 micron, the wear resistance will not be sufficient;
When the thickness exceeds microns, cracks are more likely to occur. The compositions of the invention can be applied to plastic substrates such as polycarbonate, polymethyl methacrylate, polystyrene and polyvinyl chloride. If adhesion is a particular problem, a primer treatment can provide a coating film with sufficiently effective adhesion. The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited by these Examples. Note that parts and % in the examples indicate parts by weight and % by weight, respectively. The performance of the coating film was evaluated using the following method. That is, abrasion resistance: The resistance to scratching was examined by rubbing with #0000 steel wool and judged as follows. A: No damage occurs even if strongly rubbed. B: Slight scratches occur when rubbed strongly. C: If rubbed strongly, it will be seriously damaged. D: Even weak friction causes scratches. Adhesion: In the so-called cross-cut tape test, 11 parallel lines were placed vertically and horizontally at 1 mm intervals on the surface of the coating film, and 100 squares were cross-cut.
After adhering a cellophane adhesive tape thereon, the tape was peeled off, and the number of squares that did not peel off among 100 squares was indicated. Hot water resistance: The state of the coating film was examined after being immersed in boiling water for 1 hour. Thermal properties: The state of the coating film was examined after being stored in a hot air drying oven at 120°C for 100 hours. Chemical resistance: The state of the coating film was examined after being immersed in the following chemicals at room temperature for 50 hours. 3% sulfuric acid, 1% sodium hydroxide, 95% ethanol, acetone, ethyl acetate, carbon tetrachloride,
Toluene, n-heptane, 10% saline. Dyeing: Sumikaron Blue, a common disperse dye
Add 1 part of E-FBL (manufactured by Sumitomo Chemical Co., Ltd.) and 1 part of the dispersant Sumipon TF (manufactured by Sumitomo Chemical Co., Ltd.) to water.
The immersion treatment was carried out in a dye bath containing 300 parts at 90°C for 20 minutes. The degree of staining of the dyed sample is measured by visible light transmittance, and if the value is 80% or less, it can be determined that the stainability is good. The light fastness was determined by a dye fastness test against carbon arc lighting (JIS L-0842-1971) for 100 hours. Examples 1 to 4 (1) Preparation of glycidyl methacrylate (30 parts)-hydroxyethyl methacrylate (70 parts) copolymer solution (A-1). Add 18 parts of glycidyl methacrylate, 42 parts of hydroxyethyl methacrylate, and 0.3 parts of azobisisobutyronitrile to 140 parts of ethyl cellosolve and raise the temperature to 90°C while stirring gently. The process continues for about 4 hours while constantly blowing nitrogen. The resulting solution is pale yellow in color and has a viscosity of approx.
It became a liquid of about 80 cps, and a copolymer of glycidyl methacrylate and hydroxyethyl methacrylate was formed. (2) Epoxy compounds (A-2 to A-4) Those shown in Table-1 were used.

[Table] (3) Colloidal Silica Isopropyl alcohol colloidal silica (manufactured by Catalysts & Chemicals Co., Ltd., solid content 30%) (B-1) was used. (4) Curing catalyst 10% aqueous solution of ammonium perchlorate (C-
1) was used. (5) Preparation of paint Mix components (A), (B) and curing catalyst in the proportions shown in Table 2, add a small amount of flow control agent, and dilute with ethyl cellosolve so that the solid content is 20-40%. It was made into a paint. (6) Painting Pre-cleaned diethylene glycol bisallyl carbonate polymer (product name CR-39)
Apply the above paint to a flat plate using the dipping method and heat it at 130°C.
Cured by heating for hours. Further, staining was carried out using the method described above. Table 2 summarizes the coating film performance before and after dyeing.

[Table] Example 5 140 parts of ethyl cellosolve, 42 parts of glycidyl methacrylate, 18 parts of hydroxyethyl methacrylate
1 part and 0.3 part of azobisisobutyronitrile and raise the temperature to 90°C while stirring gently. The process continues for about 4 hours while constantly blowing nitrogen.
The resulting solution was a pale yellow liquid with a viscosity of approximately 70 cps (molecular weight approximately 20,000), and a copolymer of glycidyl methacrylate and hydroxyethyl methacrylate was formed. 200 parts of ethyl cellosolve, 160 parts of the above copolymer
Part, colloidal silica (isopropyl alcohol colloidal silica, manufactured by Catalysts Kasei Kogyo Co., Ltd., solid content 30
%) 200 parts, 10% aqueous solution of ammonium perchlorate
12 parts and a small amount of flow control agent were added to prepare a paint. The above paint was applied to a CR-39 flat plate that had been cleaned in advance, and cured by heating and drying in a hot air drying oven at 130°C for 1 hour. The coating film thus obtained was colorless and transparent, and its abrasion resistance was A. No abnormality was observed in the appearance after hot water and heat resistance tests.
Adhesion was good at A and 100/100. Further, after the chemical resistance test, no abnormality was observed in the appearance and the product was in good condition. Furthermore, after leaving the above coating material at room temperature for about one month, the coating film was applied and cured in the same manner, and the performance of the coating film was as good as above. Example 6 The preparation of the copolymer in Example 5 was repeated by adding 30 parts of glycidyl methacrylate, 12 parts of methyl methacrylate, 18 parts of hydroxyethyl methacrylate and 0.3 parts of asobisisobutyronitrile to 140 parts of ethyl cellosolve. The resulting solution turned into a pale yellow liquid with a viscosity of about 120 cps, and a copolymer of glycidyl methacrylate, methyl methacrylate, and hydroxyethyl methacrylate was formed. 100 parts of ethyl cellosolve, 160 parts of the above copolymer
Department. Colloidal silica (manufactured by Isopropyl Alcohol Colloidal Silica Catalysts & Chemicals Co., Ltd., solid content 30
%), 10 parts of a 10% aqueous solution of ammonium perchlorate, and a small amount of a flow control agent were added to prepare a paint. The above paint was applied to a CR-39 flat plate that had been cleaned in advance, and was heated and dried in a hot air drying oven at 130°C for 1 hour to cure it. The coating film obtained in this way is colorless and transparent, has an abrasion resistance of A, shows no abnormalities in appearance after hot water and heat resistance tests, and has good adhesion.
It was good at 100/100. The appearance after the chemical resistance test was also good. Comparative Example 1 To 120 parts of the copolymer solution of glycidyl methacrylate and bidroxyethyl methacrylate described in Example 5, 280 parts of colloidal silica (isopropyl alcohol colloidal silica, manufactured by Catalysts Kasei Kogyo Co., Ltd., solid content 30%) and aluminum acetylacetonate were added. 24 parts of a 10% benzene solution and a small amount of a flow control agent were added to prepare a paint. The above paint was applied to a CR-39 flat plate that had been cleaned in advance, and cured by heating and drying in a hot air drying oven at 130°C for 1 hour. The coating film thus obtained had poor adhesion to the substrate and had a tendency to lift and peel. Comparative Example 2 A paint prepared in the same manner as in Example 5 except that 1.2 parts of perchloric acid was used instead of 12 parts of a 10% aqueous solution of ammonium perchlorate was left at room temperature for 3 days, and then pre-washed CR-39 was used. It was applied onto a flat plate and cured by heating and drying in a hot air drying oven at 130°C for 1 hour. The resulting coating film is colored and has a wear resistance of D.
It was hot. Example 7 The paint described in Example 5 was coated on a bisphenol type polycarbonate plate that had been previously treated with the primer of the acrylic polymer example, and cured by heating and drying in a hot air drying oven at 130°C for 1 hour. The coating film thus obtained was colorless and transparent, and its abrasion resistance was A. No abnormality was observed in the appearance after hot water and heat resistance tests, and its abrasion resistance and adhesion were A, 100/100.
It was good.

Claims (1)

[Claims] 1 The following (A), (B) and (C) (A) (a) Epoxy compound, provided that the general formula [Formula] (wherein R ⁵ is an organic group having an epoxy group,
R ⁶ is hydrogen, a hydrocarbon group having 1 to 6 carbon atoms, a vinyl group, R ⁷ is a hydrocarbon group having 1 to 5 carbon atoms,
an alkoxyalkyl group or an acyl group having 1 to 4 carbon atoms, b is 1 to 3, c is 0 to 2, and b+c≦3. ⁾ Excluding the hydrolyzate of a silicon compound having ^an epoxy group represented by
It represents a lower alkyl group or a carboxyl group, and X represents a side chain having an epoxy group. ) A coating composition containing at least one polymer or copolymer selected from the group consisting of (B) colloidal silica having a particle size of 1 to 100 millimicrons (C) ammonium perchlorate.