Patent ID: 8163391
Filing Date: 2012-04-24
Classification: C08G,C09D,C23C,Y10T

Abstract:
1. A surface treated steel sheet comprising: a surface treatment film comprising a metallic compound containing titanium, a metallic compound containing magnesium, a cationic urethane resin having at least one cationic functional group selected from primary to tertiary amino groups and quaternary ammonium bases, and a cationic phenol polycondensate, wherein the cationic phenol polycondensate is a polycondensate of a phenol compound with an aldehyde and has a cationic functional group, wherein the titanium content in the surface treatment film is in the range of 1 mass % to 4 mass % based on a total solid content, the magnesium content in the surface treatment film is in the range of 0.2 mass % to 2 mass % based on a total solid content, the cationic urethane resin content in the surface treatment film is in the range of 20 mass % to 35 mass % based on a total solid content, the cationic phenol polycondensate content in the surface treatment film is in the range of 25 mass % to 40 mass % based on a total solid content, and the mass ratio of the cationic urethane resin to the cationic phenol polycondensate is in the range of 33.3:66.7 to 45.2:54.8.