MULTI-LAYERED FILM PAINTED WITH POWDERY PAINT FOR COATING STEEL PIPE

摘要

PURPOSE: Provided is a multi-layered film painted with powdery paint for coating steel pipe, which substantially overcomes problems, such as high cost and working-difficulty of polyolefin multi-coating system arising when steel pipe is typically coated, and limited physical property of one-ply coating system of fusion bonded epoxy. CONSTITUTION: The multi-layered film comprises bottom coat of powdery epoxy paint and top coat of powdery polyester paint. The powdery epoxy paint comprises 20-50 wt% of bisphenol A type of epoxy resin having epoxy equivalent of 400-3000; 5-20 wt% of novolac or cresol modified epoxy resin having epoxy equivalent of 400-1100, which is blended with 0.1-20% of 3-glycidoxy propyl trimethoxysilane, as silane coupling agents; 0.5-7 wt% of hardeners; 40-50 wt% of inorganic fillers; and 0.01-1.0 wt% of hardening aids. The powdery polyester paint comprises 50-70 wt% of carboxyl terminated polyester resin having acid value of 24-36 and molecular weight of 5,000-20,000; 3-5 wt% of triglycidyl isocyanurate hardeners; 0.1-2 wt% of glycidylmethacrylate hardeners; 0.01-0.1 wt% of hardening stimulants; 5-10 wt% of titanium dioxide; and 5-30 wt% of inorganic fillers.