Production of anticorrosion coating on iron with good adhesion and weather resistance and reversibility

摘要

Production of an anticorrosion coating on iron and/or articles containing iron involves applying layer(s) containing a polycondensation product (I). (I) is prepared by (a) precondensation of 30-40 mole-% organic uncurable organo-functional silane of formula R'pSix4-p (II) with 60-70 mole-% organic curable organo-functional silane of formula R"m(R"'Y)n(4-m-n) (III) at 0-100 deg C without externally added solvent; and (b) hydrolysis/condensation of this precondensate with a stoichiometric amount of water for 0.5-120 hours at 0-100 deg C. In the formulae, R' = aryl; X = hydroxyl (OH), chlorine (Cl) or alkoxy; R" = alk(en)yl, aryl, alk(en)ylaryl or arylalk(en)yl; R"' = alk(en)ylene, arylene, alk(en)ylarylene or arylalk(en)ylene; R" and R"' may have oxygen (O), sulphur (S) or imino (-NH-) in the chain; X' = hydrogen (H), halogen, OH, alkoxy, acyloxy or -NR2; R = H or alkyl; Y = a polymerisable group; m, n = 0-3; (m+n), p = 1-3. Then (c) (I) is taken up in an organic solvent with a dilution ratio (in wt.%) of (I) to solvent of 1:(0.1-10) and, if R" = 3-glycidoxy propyl, 0.1-50 mole-%, with respect to (I), of an aminosilane is added as hardener; and (d) this solution is applied to the article in the form of layer(s), each 0.5-20 mu m thick.