Method of treating the surfaces of shaped articles of polycarbonate resins

Claim 1

A method of treating the surface of a shaped article of a polycarbonate resin, which comprises coating the shaped article of the polycarbonate resin with (I) a pre-treating solution containing a bisphenol type epoxy resin in a concentration of 5 to 50 wt% in a mixed solvent of a lower alcohol and an alkyl ether of ethylene glycol, air-drying the coated article, then coating the article with (II) a coating composition comprising (A) a reaction mixture of the reaction of an aminoalkylalkoxy silane of the general formula ##STR13## wherein R 1 represents a divalent hydrocarbon group containing 1 to 4 carbon atoms, R 2 and R 3 represent a monovalent hydrocarbon group containing 1 to 4 carbon atoms, Z represents a hydrogen atom or an aminoalkyl group, and n is 0 or 1, with an epoxyalkylalkoxy silane of the general formula ##STR14## wherein R 1 , R 2 and R 3 are as defined above, Q represents a glycidoxy group or an epoxycyclohexyl group, and m is 0 or 1, (B) a mixture of 10 to 0 wt% of an alkyl-modified methylol melamine of the general formula ##STR15## wherein R 4 , R 5 , R 6 , R 7 , R 8 and R 9 represent a hydrogen atom or a monovalent hydrocarbon group with 1 to 4 carbon atoms, and 90 to 100 wt% of an alkyd resin 4, and (C) an acrylic acid derivative of the general formula ##STR16## wherein R 10 represents a hydrogen atom or a methyl group, and R 11 represents a hydrogen atom, a hydrocarbon group containing 1 to 4 carbon atoms, a hydroxyalkyl group or a glycidyl group, or its polymer of a low degree of polymerization, the content of the component (A) being 45 to 100 wt% and the content of the component (B) being 55 to 0 wt% in the mixture of the components (A) and (B), and the content of the component (C) in the composition of the components (A), (B) and (C) being 5 to 30 wt%, and heat-curing the coated article.

Claim 2

A method of treating the surface of a shaped article of a polycarbonate resin, which comprises coating the shaped article of the polycarbonate resin with (I) a pre-treating solution containing a bisphenol type epoxy resin in a concentration of 5 to 50 wt% in a mixed solvent of a lower alcohol and an alkyl ether of ethylene glycol, air-drying the coated article, then coating the article with (II) a coating composition comprising (A) a reaction mixture of the reaction of an aminoalkylalkoxy silane of the general formula ##STR13## wherein R 1 represents a divalent hydrocarbon group containing 1 to 4 carbon atoms, R 2 and R 3 represent a monovalent hydrocarbon group containing 1 to 4 carbon atoms, Z represents a hydrogen atom or an aminoalkyl group, and n is 0 or 1, with an epoxyalkylalkoxy silane of the general formula ##STR14## wherein R 1 , R 2 and R 3 are as defined above, Q represents a glycidoxy group or an epoxycyclohexyl group, and m is 0 or 1, (B) a mixture of 10 to 0 wt% of an alkyl-modified methylol melamine of the general formula ##STR15## wherein R 4 , R 5 , R 6 , R 7 , R 8 and R 9 represent a hydrogen atom or a monovalent hydrocarbon group with 1 to 4 carbon atoms, and 90 to 100 wt% of an alkyd resin 4, and (C) an acrylic acid derivative of the general formula ##STR16## wherein R 10 represents a hydrogen atom or a methyl group, and R 11 represents a hydrogen atom, a hydrocarbon group containing 1 to 4 carbon atoms, a hydroxyalkyl group or a glycidyl group, or its polymer of a low degree of polymerization, the content of the component (A) being 45 to 100 wt% and the content of the component (B) being 55 to 0 wt% in the mixture of the components (A) and (B), and the content of the component (C) in the composition of the components (A), (B) and (C) being 5 to 30 wt%, and heat-curing the coated article.