| 摘要 |
PURPOSE:To form a coated film having excellent heat resistance and adhesion by using an electrophoretic bath obtained by neutralizing the carboxyl group of a polyamido acid having a repeating unit of a specified structure and diluting the product with water to form a coated film on a metallic body, and heating the coated film to iminate the film. CONSTITUTION:The carboxyl group of the polyamido acid consisting of the repeating unit shown by formula I is neutralized with a base, and the product is diluted with water to prepare an electrophoretic bath for forming film. In the formula, R1 is a tetravalent group selected from the noncondensable polycyclic aromatic groups wherein a >=2C aliphatic group, an alicyclic group, a monocyclic aromatic group, etc., are interconnected, and R2 shows a bivalent aromatic group selected from the groups shown by formulas II-IX and having a link-bond at its meta position. A metallic body is dipped in the bath, and electrophoresis is carried out to deposit a polyamido acid on the surface of the metallic body. The coated film is heated to iminate the coated film. By this method, a heat-resistant coated film can be formed with good adhesion on the surface of the metallic part of a complicated shape.
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