Pigmentos inorgânicos para aplicação em plásticos

Abstract

Inorganic pigments have been known since prehistoric times. However, it has begun produced in large scale in the 18th century. These pigments have several advantages when applied for coloring plastics. Plastics are materials with unique properties, responsible for major technological innovations in the last century. The objective of this study is to investigate the pigmentation of plastics by heat fastness and light fastness tests, for commercial purposes. The specimens were molded by injection using polypropylene and different classes of inorganic pigments. For each inorganic pigment two platelets were prepared, one in full shade and one in reduction. The characterization of the specimens is made by optical reading of the CIEL*a*b* parameters after retention times in the injector cylinder at different temperatures and evaluation using the blue wool scale after exposure in Xenotest. The structural and electronic properties responsible for the color of each selected pigment are highlighted. These structures are also related to the color change of the specimens in the light and temperature fastness tests. The pigments in the “Transcor’s pigments and dyes for plastics” catalog have good representativeness, showing properties, characteristics and samples to its customers. Keywords: Inorganic pigments, coloring of plastics