Coating material composition for chromium plating and article comprising coating film made of the same
According to the present invention, there are provided a coating material composition for chromium plating, which can maintain high adhesion to the chromium plated surface of a chromium plated material having reduced adhesion for a long period and also can form a coating film having excellent chemical resistance, and an article comprising a coating film made of the same. The coating material composition for chromium plating, comprises a vinyl-based polymer (A) obtained by polymerizing a vinyl-based monomer mixture containing a vinyl-based monomer having an amino group, and a compound (B) having an epoxy group and a hydrolyzable silyl group in a molecule, wherein the vinyl-based polymer (A) has a glass transition temperature of lower than 30° C., and the content of the vinyl-based monomer having an amino group is 5% by weight or more and less than 20% by weight in the vinyl-based monomer mixture (100% by weight).
1. A coating material composition for chromium plating, comprising a vinyl-based polymer (A) obtained by polymerizing a vinyl-based monomer mixture containing a vinyl-based monomer having an amino group, a compound (B) having an epoxy group and a hydrolyzable silyl group in a molecule, and a compound (C) having a hydrolyzable silyl group other than the compound (B), wherein
the vinyl-based polymer (A) has a glass transition temperature of lower than 30° C.,
the content of the vinyl-based monomer having an amino group is 5% by weight or more and less than 20% by weight in the vinyl-based monomer mixture (100% by weight), and the compound (C) having a hydrolyzable silyl group that is a mixture of a partial hydrolyzate condensate (C1) of tetramethoxysilane and a partial hydrolyzate condensate (C2)of tetraethoxysilane.
2. The coating material composition for chromium plating according to claim 1 , wherein a weight ratio of the partial hydrolyzate condensate (C1) to the partial hydrolyzate condensate (C2), (C1/C2), is from ½ to ¼.
3. An article comprising a chromium plated base material and a coating film made of the coating material composition for chromium plating according to claim 1 or 2 formed on the chromium plated surface of the base material.
4. The article according to claim 3 , wherein the chromium plated surface of the base material is pretreated with an organic silicon compound.