Coating compsn. for iron or steel sheet - comprises alkali silicate-poly:phosphate sol and opt. a boron cpd. and an acrylate! copolymer

摘要

A non-metallic coating contains an alkali silicate-polyphosphate sol (I) with a mol. ratio of silicate (calculated as SiO2) to alkali oxide (calculated as M2O) of 3-4:1 and a mol. ratio of polyphosphate (calculated as P2O5) to alkali oxide of 0.05-0.5:1. Pref. coating also comprises 0.2-1.0 wt. % acrylate copolymer to improve elasticity. The coating can be used in thicknesses of 2-20 mu, has good stampability and is not hygroscopic. The compsn. may also be used as an adhesive for insulation paper instead of water-glass soln.