Polymeric material and its manufacture and use

1. A method for producing a microporous membrane comprising the steps of:

combining a diluent or solvent and a first polyolefin composition to prepare a first polyolefin solution, the first polyolefin composition comprising greater than about 90 mole % propylene monomer and having one or more of the following:

i. an intrinsic viscosity greater than about 10 dl/g;

ii. a heat of fusion greater than about 108 J/g, a melting point of 165° C. or greater;

iii. a molecular weight greater than about 1.5×10 6 ;

iv. a molecular weight distribution of from about 2.5 to about 7;

v. a Melt Flow Rate at 230° C. of less than about 0.01 dg/minute;

vi. an amount of extractable species of 0.5 wt. % or less based on the weight of the polyolefin composition;

vii. a meso pentad fraction of greater than about 96 mol % mmmm pentads; and

viii. an amount of stereo defects less than about 50 per 10,000 carbon atoms;

extruding the first polyolefin solution through at least one die to form an extrudate;

removing at least a portion of the membrane-forming solvent from the cooled extrudate or extrudate to form a solvent-removed sheet; and

drying the sheet to form the microporous membrane.

2. The method of claim 1 , further comprising stretching the microporous membrane after drying, and conducting one or more of stretching the microporous membrane and cross-linking the microporous membrane using ionizing radiation.

3. The method of claim 1 , further comprising combining a second polyolefin composition and a second membrane-forming solvent to prepare a second polyolefin solution, and extruding the second polyolefin solution through at least one die to form a multilayer extrudate.

4. The method of claim 3 , further comprising cooling the extrudate to form a cooled extrudate prior to step removing the portion.

5. The method of claim 1 , wherein the first polyolefin composition has an mmmm pentad fraction of greater than about 96 mol % mmmm pentads.

6. The method of claim 1 , wherein the first polyolefin composition has greater than about 99.99 mol % propylene monomer.

7. The method of claim 1 , wherein the first polyolefin composition has a molecular weight greater than about 1.75×10 6 .

8. The method of claim 7 , wherein the first polyolefin composition has an intrinsic viscosity greater than about 11 dl/g, a heat of fusion greater than about 110 J/g, a melting point of 166° C. or greater, a molecular weight greater than about 1.5×10 6 , a molecular weight distribution of from about 2.5 to about 7, a Melt Flow Rate at 230° C. of less than about 0.01 dg/minute, and stereo defects less than about 40 per 10,000 carbon atoms.

9. The method of claim 8 , wherein the first polyolefin composition comprises greater than about 95 mole % propylene monomer.

10. The method of claim 8 , wherein the first polyolefin composition comprises greater than about 99.99 mole % propylene monomer.

11. The method of claim 8 , wherein the first polyolefin composition comprises a molecular weight greater than about 2.0×10 6 .

12. The method of claim 11 further comprising a second polyolefin composition.

13. The method of claim 1 , wherein the first polyolefin composition comprises polyethylene and a propylene polymer composition comprising greater than about 90 mole % propylene monomer, said propylene polymer composition having an intrinsic viscosity greater than about 10 dl/g, a heat of fusion greater than about 108 J/g, a melting point of 165° C. or greater, a molecular weight greater than about 1.5×10 6 , a molecular weight distribution of from about 2.5 to about 7, a Melt Flow Rate at 230° C. of 0.2 dg/minute or less, and stereo defects less than about 50 per 10,000 carbon atoms.

14. The method of claim 13 , wherein the polyethylene comprises a first polyethylene having a molecular weight of 5×10 5 or more, a second polyethylene having a molecular weight of 1×10 4 or more and less than 5×10 5 , or both the first and second polyethylenes.

15. The method of claim 14 , wherein the first polyethylene comprises ultra high molecular weight polyethylene and the second polyethylene comprises at least one of high-density polyethylene, medium-density polyethylene, branched low-density polyethylene, and linear low-density polyethylene.

16. The method of claim 14 , wherein the ultra high molecular weight polyethylene is an ethylene homopolymer or an ethylene/α-olefin copolymer containing a small amount of an α-olefin other than ethylene.

17. The method of claim 13 , wherein the propylene polymer composition has an intrinsic viscosity greater than about 11 dl/g, a heat of fusion greater than about 110 J/g, a melting point of 166° C. or greater, a molecular weight greater than about 1.5×10 6 , a molecular weight distribution of from about 2.5 to about 7, a Melt Flow Rate at 230° C. of less than about 0.01 dg/minute, an amount of extractable species of 0.5 wt. % or less based on the weight of the propylene polymer composition, and stereo defects less than about 40 per 10,000 carbon atoms.

18. A microporous membrane made by the method of claim 1 .

19. A battery comprising an anode, a cathode, an electrolyte, and the microporous membrane of claim 18 , wherein the microporous membrane is located at least between the anode and the cathode.

20. A microporous membrane made by the method of claim 13 .

21. A battery comprising an anode, a cathode, an electrolyte, and the microporous membrane of claim 20 , wherein the microporous membrane is located at least between the anode and the cathode.