合成高分子防水層の耐候性その 5 : 防水用高分子材料のウェザーメータ試験と光熱劣化試験

抄録

Fourteen types of rubber and plastic sheets for roof membranes were selected in the Japanese market and tested by so-called Weather Meter, in which test specimens were exposed to ultra-violet ray from Sunshine Carbon-Arc and periodically to water spray. The results obtained show a general tendency that elongations at break decrease and stresses at 300%-elongation increase as the test goes on. We cannot find out, however, a definite accelerating ratio between the results obtained here and ones by outdoor exposure tests in Tokyo and Sapporo. For the purpose of making clear the degradation of these sheets, a separate estimation of the effect of heat and light is fundamentally needed. Therefore, the following improved accelerated weathering test was made. Test specimens specially produced for this test were exposed to ultra-violet ray from Xenon-Arc at three kinds of ambient temperatures, 6℃, 66℃ and 85℃. The results obtained show an obvious tendency that the degradation of the test specimens exposed to light of the same intensity is more accelerated by the higher ambient temperature, and that clear sheets are much more sensitive to light than opaque ones.