Abstract
The influence of pigments, dispersed in polypropylene, upon its degradation by ultra-violet ray was studied. The result has shown a remarkable influence of the pigments and suggested the necessity of precaution in their applications. From a further study of the influence of various metalic chlorides, oxides and metal itself and study of screening effects of various pigment contained in polypropylene, it was concluded that the influence upon degradation could not be explained merely by the screening effect unless the catalytic action, in detail of which was reported in previous report, of metals contained in the pigments is taken into consideration.
