Patent Number: 059088842
Section: abstract

Tungsten powder which is a material of high radiation absorptivity is dispersed into unvulcanized fluoro rubber in advance so that the mixture is vulcanized and molded. As the powder of material of high radiation absorptivity, powder having an F.s.s.s. particle size not larger than 50 .mu.m is used. Further, in the case where a mixture of powder having an F.s.s.s. particle size in a range of from 5 .mu.m to 50 .mu.m, and powder having an F.s.s.s. particle size in a range of from 0.5 .mu.m, to 5 .mu.m, is used as the powder of material of high radiation absorptivity, the powder of material of high radiation absorptivity has good tensile strength, good extensibility and more excellent radiation shielding ability, when the weight of the powder having a particle size in a range of from 4 .mu.m to 100 .mu.m is in a range of from 60% by weight to 95% by weight, and the weight of the powder having a particle size smaller than 4 .mu.m is in a range of from 5% by weight to 40% by weight. Both the powder and the vulcanized rubber containing carbon powder have electrical conductivity, so that electromagnetic wave shielding ability is added. In addition, the vulcanized rubber is vulcanized fluoro rubber which is excellent in heat resistance and chemical resistance.