| 摘要 |
1,226,236. Polyolefin films. HERCULES Inc. 21 Feb., 1969 [23 Feb., 1968], No. 9597/69. Heading B5B. [Also in Divisions C3 and D1] A dispersion of crystalline polypropylene or ethylene/propylene copolymer, of particle size 0À02-0À5Á, in kerosene is made into porous films in examples 2, 3 and 5-8 by pouring into a mould or on a panel, heating to form a solution, cooling to form a gel and extracting the gel with butanol, methanol, xylene, acetone and/or isopropanol, and then dried. |
