ORGANIC COMPOSITE COATED STEEL PLATE HAVING EXCELLENT OUTER SURFACE CORROSION RESISTANCE AND IMAGE CLARITY AND ITS PRODUCTION

摘要

PURPOSE: To secure mainly excellent outer surface corrosion resistance and image clarity by laminating a specified chromate layer as a primary layer and a specified organic film consisting essentially of a urethane-modified epoxy resin as secondary layer on a zinc electroplated steel plate. ;CONSTITUTION: An organic composite coated steel plate is constituted of chromate layer provided as a primary layer on a zinc electroplated steel plate and, upper the primary layer, an organic coating layer as secondary layer. The chromate layer is specified to 10-200mg/m³ attached quantity expressed in terms of metallic chromium. On the other hand, organic coating is composed by adding a rust preventive additive (D) to an urethane-modified epoxy resin (C) at a wt. ratio of C/D=90/10-50/50 which is formed by allowing an epoxy resin (A) to react with an urethane prepolymer (B) consisting of a polyol and a polyisocianate at wt. ratio of A/B=95/5-50/50 and the thickness of the coating is specified to 0.2-2μm.;COPYRIGHT: (C)1993,JPO&Japio