摘要 |
Microporous material comprises: (1) a matrix comprising a mixture of substantially linear ultrahigh molecular weight polyethylene having an intrinsic viscosity of at least about 10 deciliters/gram and lower molecular weight polyethylene having an ASTM D 1238-86 Condition E melt index of less than about 50 grams/10 minutes and an ASTM D 1238-86 Condition F melt index of at least 0.1 gram/10 minutes, (2) a large proportion of finely divided water-insoluble siliceous filler, and (3) interconnecting pores wherein the weight percent of the ultrahigh molecular weight polyethylene in the total polyethylene of the matrix and the filler/matrix weight ratio are within the polygon ABCDEF of FIG. 6 of the drawings.
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