发明授权
US5304401A Method of producing organic composite-plated steel sheet 失效
生产有机复合镀钢板的方法

Method of producing organic composite-plated steel sheet
摘要:
The present invention provides a method for producing a highly corrosion resistant organic composite-plated steel sheet which is inhibited from liberation of chromium, which comprises forming a chromate film comprising a composition of the following (A) as a first layer at a coating amount of 5-150 mg/m.sup.2 as a solid film on the surface of a zinc or zinc alloy plated or zinc composite alloy plated steel sheet and then, coating on the first layer an organic solvent coating composition of the following (B) as a second layer at a thickness of 0.3-5 .mu.m as a solid film.(A) coating type chromate bath composition1 Cr.sup.6+ : 1-30 g/l,2 Cr.sup.3+ : 1-30 g/l,3 Cr.sup.6+ /Cr.sup.3+ weight ratio: 0.2-2.0,4 HF+H.sub.3 PO.sub.4 : 1-60 g/l,5 HF+H.sub.3 PO.sub.4 /Cr.sup.3+ weight ratio: 0.5-3.5, and6 silane coupling agent/Cr.sup.6+ molar ratio: 0.05-0.3(B) organic solvent coating composition(a) a bisphenol epoxy resin having a number-average molecular weight of 300-100,000 in an amount of 30% by weight or more based on the solid content of the coating composition;(b) at least one curing agent selected from the group consisting of polyisocyanate compounds and blocked polyisocyanate compounds at 1/10-20/10 in a weight ratio to solid content of the epoxy resin;(c) fumed silica of 0.1-100 m.mu. in an average particle size in an amount of 5-50% by weight based on the solid content of the coating composition;(d) a ketone type organic solvent in an amount of 40% by weight or more based on the weight of the coating composition; and the solid content of the coating composition being in the range of 10-50% by weight.
信息查询
0/0