| 摘要 |
The invention comprises a solid, highly crystalline polypropylene having a tensile strength at yield of at least 5,500 p.s.i., a stiffness of at least 180,000 p.s.i. and a limiting melting point as herein defined of at least 180 DEG C. A propylene polymer may contain at least 80% of the above polypropylene the balance consisting of non-crystalline polypropylene. The product may be formed into shaped articles, pellicles, photographic film bases, magnetic tapes, fibres or filaments. The product may be prepared by the processes described and claimed in Specifications 920,118, 920,119, 920,120, 920,121, 920,512, 920,631, 920,632, 920,633, 920,634 and 921,039, as well as, and preferably in 921,636. Specifications 777,538 and 790,195 also are referred to.
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