1986 Volume 72 Issue 14 Pages 1905-1912
For light-weight steel sheets which consist of skin steels and thermoplastic resin, strong adhesion between skin steels and resin is required to get excellent qualities. To improve durability of the adhesion-strength, various surface pre-treatments were examined. Experimental results showed that pre-treatment for skin steels was effective to get the good adhesion-durability. Chromate treatment showed the most suitable effect and when the coating weight of Cr is 40 mg/m2, the light-weight steel sheet has the highest adhesion strength and corrosion resistance. This excellent durability is considered to be due to the strong and stable bonding between polarized base of PP resin and hydrized Cr-oxide on the surface of chromate layer. Silane-coupling-agent and organic resin are effective for improving initial adhesionstrength between steel and resin, however they are inferior to chromate treatment on the durability, especially on the corrosion resistance.