POLYUREA COMPOSITION FOR ANTI-CORROSION PROTECTIVE COATING OF STEEL SURFACES

摘要

FIELD: technological processes.;SUBSTANCE: invention relates to a polyurea composition for coatings on a metal surface. Polyurea composition consists of two components of an isocyanate prepolymer based on diphenylmethane diisocyanate and a curable component with active hydrogen atoms of the amino groups. Isocyanate prepolymer further comprises hexamethylene diisocyanate. Curable component comprises an epoxide-modified polyether amine of a molecular weight of 2,000–3,000, a polyetheramine of 400 molecular weight, diethyltoluene diamine, 3,3'-dichloro-4,4'diaminodiphenylmethane and polysulfide polymer with a content of thiol groups of at least 3 %. Mass fraction of the isocyanate groups of the isocyanate prepolymer is 18–20 % and the dynamic viscosity 0.8–2.0 Pa*s at 25±0.1 °C. Amine number of the second component with the active hydrogen atoms is 20–60 mg KOH/g. Ratio of the components of the polyurea composition is, mass parts: 40–50 of modified epoxy polyester, 4–15 of polysulfide polymer, 25–35 of diethyltoluylenediamine, 5–10 of 3,3'-dichloro-4,4'diaminodiphenylmethane, 10–20 of polyetheramine of molecular weight of 400, 0.5 of carbon black or other pigment, 1.0 of fine-dispersed titanium dioxide, 40–60 of trimerized isocyanate HDI and 40–50 of prepolymer based on MDI.;EFFECT: produced polyurea composition allows to obtain coatings on the surface of the metal with improved physical and mechanical properties, and also simplifies the coating process.;1 cl, 3 tbl, 3 ex