| 摘要 |
PROBLEM TO BE SOLVED: To provide a soft and bright product which control cracks generated by stress, prevents the appearance quality from being lowered, and is highly inhibitive against corrosion and also highly weather-proof. SOLUTION: A front grille 1 is composed of a base material 2 of polypropylene containing rubber, a base coat layer 3, a metallic thin film layer 4 with a thickness of 150-800Å, and a top coat layer 5. The metallic thin film layer 4 is formed in chromium, and is macroscopically recognized as a metallic film and is microscopically made of a tissue such as filled densely with metal microparticles, forming a crystal grain boundary 6. If some stress is applied inwardly, the base material 2, the base coat layer 3 and the top coat layer 5 could be deformed in compliance with the stress. In addition, the metallic thin film layer 4, having the crystal grain boundary 6, shows only such a phenomenon that the interstice between adjacent crystal grains is only widened, if such a stress is generated on the metallic thin film layer 4. Besides, the metal itself forming the metallic thin film layer 4 is almost not subjected to the stress, and therefore, no cracks are generated on the metallic thin film layer 4. |
