Patent ID: 9499914
Filing Date: 2016-11-22
CPC Classification: C08G,C09D,C23C,Y10T

Claim Text:
1. A method for manufacturing a zinc or zinc alloy coated steel sheet, comprising: preparing a surface-treatment liquid for a zinc or zinc alloy coated steel sheet, comprising components, by blending the components such that solid mass contents calculated from respective masses of the components satisfy conditions (I) to (V), where the surface-treatment liquid has a pH in the range of 3 to 6, the components including: (A) a resin emulsion formed of (A-1) a cationic urethane resin emulsion having at least one type of cationic functional group selected from the group consisting of primary to tertiary amino groups and quaternary ammonium group and/or (A-2) a non-ionic acrylic resin emulsion; (B) a tetraalkoxysilane; (C) at least one type of silane coupling agent having at least one type of reactive functional group selected from the group consisting of an active hydrogen-containing amino group, epoxy group, mercapto group, and methacryloxy group; (D) a chelating agent; (E) a vanadate compound; (F) a titanium compound; and water; and applying by coating the surface-treatment liquid to a surface of a zinc or zinc alloy coated steel sheet, heating and drying the surface of the zinc or zinc alloy coated steel sheet such that a coating amount per surface is in the range of 200 to 1,000 mg/m wherein the conditions (I) to (V) are as follows: (I) solid content (A (II) solid mass ratio (C (III) solid mass ratio (B (IV) solid mass ratio (E (V) solid mass ratio (F