| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a coating composition of which the cured coating film develops scratch resistance and UV-shielding properties while maintaining transparency to visible light and also has weatherability and durability sustainable during long-term outdoor exposure, and a coated article coated with the composition. <P>SOLUTION: A UV-shielding coating composition contains (A) a dispersion of composite zinc oxide fine particles that is obtained by dispersing composite zinc oxide fine particles, which is obtained by coating surfaces of zinc oxide fine particles with at least one selected from an oxide or a hydroxide of Al, Si, Zr and Sn, in a dispersing medium, and that has photocatalytic degradability 12 hours after black light irradiation of 25% or less in evaluation of photocatalytic degradability which is calculated from the following formula: photocatalytic degradability (%)=[(A0-A)/A0]×100 (wherein A0 is an initial absorbance and A is an absorbance after light irradiation) by using change of the absorbance at 653 nm when the dispersion of composite zinc oxide fine particles is added into methylene blue solution and absorbance at 653 nm is measured before and after black light irradiation, (B) a vinyl copolymer obtained from copolymerization of 1-50 mass% of an alkoxysilyl group-containing vinyl monomer, 5-40 mass% of a UV-absorbing vinyl monomer, and 10-94 mass% of another monomer copolymerizable with these vinyl monomers, and (C) a solvent. Also, the solid content of the composite zinc oxide in (A) the dispersion of composite zinc oxide fine particles is 1-50 mass% based on the solid content of (B) the vinyl copolymer. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
