Study on the Method of Predicting Service Life of Coated Steel Sheets (X):Degradation of Phthalocyanine Pigments in Polyvinyl Chloride Resin Coating
スポンサーリンク
概要
- 論文の詳細を見る
It has been found that the polyvinyl chloride resin; coating containing such organic pigments as phthalocyanine green or phthalocyanine blue is discolored by the outdoor weathering test in the comparatively short period. This discoloring was examined from various aspects and the results mentioned below were obtained.<BR>(1) Although the discoloring of the polyester resin coated steel sheets by the outdoor weathering test is primarily promoted by the chalking, the discoloring of the polyvinyl chloride resin coated steel sheets is accelerated by chalking and degradation of the pigment. Especially, phthalocyanine green tends to be discolored by degradation.<BR>(2) The degradation of the phthalocyanine pigment in the polyvinyl chloride resin coating appears by the heating test rather than by the dew cycle weatherometer test. In this case, an examination is required by color decomposition into a or b value instead of color difference.<BR>(3) The dehydrochlorization amount of polyvinyl chloride resin by the heating test and the degree of degradation of phthalocyanine pigments have a correlation with each other. This indicates that the degradation of the phthalocyanine pigment is promoted by the reduction of hydrogen chloride.<BR>(4) The uppermost surface layer of phthalocyanine blue is decomposed but the crystal structure thereof remains unchanged. With the decomposition of the uppermost surface layer of phthalocyanine green, on the other hand, the addition reaction of chlorine and the change of the crystal structure are also promoted.
- Japan Society of Colour Materialの論文