ORGANIC COMPOSITE COATED STEEL SHEET WITH SUPERB PRESS-MOLDING PROPERTY AND CORROSION RESISTANCE

摘要

PURPOSE: To give excellent corrosion resistance and also significantly enhanced press-molding property to a galvanized stainless steel sheet by providing a chromate layer of a specified coat thickness as a first layer on the surface of the steel sheet and a second layer of a specific organic film on the first layer. ;CONSTITUTION: A galvanized steel sheet consists of a chromate layer of 5 to 200mg/m² in terms of metallic chromium as a first layer, on the surface of the steel sheet, and a second layer, applied to the surface of the first layer, which contains 30 to 80wt.% of an epoxy resin as shown by (1), 3 to 50wt.% lubricant and 3 to 50wt.% rust inhibitive additive as shown by (2) in terms of the weight ratio of non-volatile components. The thickness of the organic film is 0.1 to 2μm. (1) is epoxy resin obtained by blending an amine-modified epoxy resin A consisting of at least, one basic nitrogen atom and two primary hydroxyl groups added to the terminal of the epoxy resin with a polyisocyanate compound B as a curing agent at a ratio of A/B=95/5 to 55/45. (2) is a lubricant selected from among a fluorine resin, graphite and boron nitride.;COPYRIGHT: (C)1995,JPO