| 摘要 |
PURPOSE:To obtain the title composition excellent in drawability, storage stability and conveyability, by mixing an ultrahigh MW polyolefin powder with a normally solid flow improver of an m.p. lower than that of said powder in two specified steps of temperature. CONSTITUTION:An ultrahigh MW polyolefin powder (A) (e.g., ultrahigh MW polyethylene powder) of an intrinsic viscosity >=5dl/g is mixed, with agitation, with a normally solid flow improver (B) of an m.p. lower than that of component A (e.g., paraffin wax or stearic acid) at a temperature ranging from the m.p. of component B to the m.p. of component A. This mixture is further melt- kneaded at a temperature higher than the m.p. of component A to obtain the purpose ultrahigh MW polyolefin composition. By melt-extruding this composition, a drawn ultrahigh MW polyolefin product having a high elastic modulus and a high tensile strength can be easily obtained.
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