| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a chromium-free primer composition which contains no chromium-based pigment and is useful for the repair coating of coated metal products such as automobile exterior plates, railroad vehicles and industrial equipment. <P>SOLUTION: The primer composition includes: a copolymer containing a tertiary amino group; pigments comprising a rust-preventive pigment and an extender pigment; and a hydrolyzable silyl compound containing an epoxy group. The rust-preventive pigment includes, as a portion of its components, a phosphoric acid/zinc-based rust-preventive pigment and a phosphoric acid/magnesium-based rust-preventive pigment. The mass ratio of the phosphoric acid/zinc-based rust-preventive pigment to the phosphoric acid/magnesium-based rust-preventive pigment is within the range of 10/90 to 90/10. The mass ratio of the rust-preventive pigment to the extender pigment is within the range of 5/95 to 95/5. The total content of the pigments is within the range of 15 to 320 pts.mass to 100 pts.mass of the resin contained in the coating material. <P>COPYRIGHT: (C)2013,JPO&INPIT |
