Weatherability of Composite Powder Coating with Two Layer Structure

Part2 InfIuence of several kinds of titaniurn oxide as color pigment on weatherability of the powder coating

Abstract

In this paper, influence of several kinds of titanium oxide as color pigment on weatherability of powder coatings is discussed based on cross-sectional observation of the coating film and 18-month-outdoor exposure test results in Okinawa. The surface of titaniumu oxide pigment is treated by several methods and the powder coatings are composite resin powder coating with two layer structure, fluorocarbon and polyester resin. Main results are as follows. (1)The wetherability of the composite resin powder coating that is free from the pigment in the coating suface layer is slightly influenced by the kinds of pigment surface treatment in harsh outdoor exposure. This is significant different characteristics from thermosetting fluorocarbon and isonate hardening type polyester powder coating which include pigment in the coating surface layer. (2)It is judged that whatherability would be able to evaluate for 2-year-term-outdoor exposure test in 28 degrees north latitude the south of Nansei Islands, as well as the reference.