| 摘要 |
283,566. Ziegner, H. Jan. 14, 1927, [Convention date]. Porous indiarubber.-Indiarubber is rendered porous by the addition of a porous material such as wood sawdust which is first saturated in a swelling medium such as benzine, the latter causing the rubber in contact with the particles of the porous substance first to swell and then, during the drying operation, to contract and loosen itself from the particles. In an example given, the mixture contains 100 parts caoutchouc, 7¢ parts sulphur, ¢ part accelerator, 50 parts lithopone, 75 parts chalk, 200 parts sawdust and 100 parts benzine. The porosity may be increased by adding water, which evaporates during vulcanization and so enlarges the capillaries. |
