A hydraulic cement-based composition for dip coating of steel and iron articles.

摘要

A cement-based composition, useful as a coating material for corrosion-resistant protection on steel and iron surfaces, comprises: (a) 100 parts by weight of a hydraulic cement; (b) from 10 to 36 parts by weight of an aqueous emulsion of a polymer capable of exhibiting good adhesion to the surface of steel and withstanding the attack of chloride ions, the amount of the emulsion being calculated as the content of the polymer therein; and (c) from 3 to 30 parts by weight of an aqueous emulsion of a hydrocarbon solvent containing from 0.5 to 2.0% by weight of a saccharide compound and a combination of from 0.8 to 2.0% by weight of a first non-ionic surface active agent soluble in the hydrocarbon solvent having an HLB value in the range from 10 to 14.5, from 0.8 to 2.0% by weight of a second non-ionic surface active agent soluble in water having an HLB value in the range from 15 to 18 and from 0.3 to 1.0% by weight of a cationic surface active agent soluble in water, the amount of the emulsion being calculated as the content of the hydrocarbon solvent and the amounts of the saccharide compound and the surface active agents each being based on the amount of the hydrocarbon solvent contained in the emulsion. By virtue of the unique formulation, the composition has a greatly extended pot-life suitable for dip-coating steel rods and pipes and the like. e