Polypropylene with weatherability and nonflammability and their manifestation mechanism

In order to avoid the danger in a fire, the flame-retardation of polymeric materials has been studied. Recently, the development of polymeric material s with not only nonflammability but also various other functions is require d. For polypropylene (PP), the development of a material with both nonflamm ability and weatherability has been one of the major themes. In the study o n this theme, we assumed that a flame-retardant, tris (tribromoneopentyl) p hosphate which generally has not been used for PP, scarcely separates bromi ne at ultraviolet radiation. At the same time we presumed that a light stab ilizer, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracar boxylate, has a low reactivity with bromine. Under these assumptions, we ha ve developed a flame-retardant PP resin with superior weatherability. The m echanism for manifestation of the effect was discussed.