US 7,682,536 B2 · Method of making a microporous material

Abstract

A method for producing a microporous material comprising the steps of: providing an ultrahigh molecular weight polyethylene (UHMWPE); providing a filler; providing a processing plasticizer; adding the filler to the UHMWPE in a mixture being in the range of from about 1:9 to about 15:1 filler to UHMWPE by weight; adding the processing plasticizer to the mixture; extruding the mixture to form a sheet from the mixture; calendering the sheet; extracting the processing plasticizer from the sheet to produce a matrix comprising UHMWPE and the filler distributed throughout the matrix; stretching the microporous material in at least one direction to a stretch ratio of at least about 1.5 to produce a stretched microporous matrix; and subsequently calendering the stretched microporous matrix to produce a microporous material which exhibits improved physical and dimensional stability properties over the stretched microporous matrix.

Claims17

Dependent claims

A method for producing a microporous material comprising the steps of:

mixing ultra high molecular weight polyethylene (UHMWPE), filler and processing plasticizer together to form a mixture, having a weight ratio of filler to UHMWPE of from 1:9 to 15:1 by weight;
extruding said mixture to form a sheet;
calendering said sheet;
extracting all or part of said processing plasticizer from said sheet to produce a matrix comprising UHMWPE and said particulate filler, the filler being distributed throughout said matrix, to produce a microporous matrix sheet;
stretching said microporous matrix sheet in at least one stretching direction to a stretch ratio of at least about1.5 to produce a stretched microporous matrix sheet;
and
calendering said stretched microporous matrix sheet.

4 more elements

A method for producing a microporous material comprising the steps of:

mixing ultra high molecular weight polyethylene (UHMWPE), filler and processing plasticizer together to form a mixture, having a weight ratio of filler to UHMWPE of from 1:9 to 15:1 by weight;
extruding said mixture to form a sheet;
calendering said sheet;
extracting all or part of said processing plasticizer from said sheet to produce a matrix comprising UHMWPE and said particulate filler, the filler being distributed throughout said matrix, to produce a microporous matrix sheet;
stretching said microporous matrix sheet in at least one stretching direction to a stretch ratio of at least about1.5 to produce a stretched microporous matrix sheet;
and
calendering said stretched microporous matrix sheet;
wherein said microporous matrix sheet having a thickness of no greater than 53.3 microns and a tensile strength in the machine direction of at least 72.9 N/mm2.

5 more elements

A method for producing a microporous material comprising the steps of:

mixing ultra high molecular weight polyethylene (UHMWPE), filler and processing plasticizer together to form a mixture, having a weight ratio of filler to UHMWPE of from 1:9 to 15:1 by weight;
extruding said mixture to form a sheet;
calendering said sheet;
extracting all or part of said processing plasticizer from said sheet to produce a matrix comprising UHMWPE and said particulate filler, the filler being distributed throughout said matrix, to produce a microporous matrix sheet;
stretching said microporous matrix sheet in at least one stretching direction to a stretch ratio of at least about1.5 to produce a stretched microporous matrix sheet;
and
calendering said stretched microporous matrix sheet;
wherein said microporous matrix sheet having a thickness of no greater than 30.5 microns and a tensile strength in the machine direction of at least 47.6 N/mm2.

5 more elements

Dependencies are inferred from the claim text.

Method of making a microporous material

Life of this patent

Method of making a microporous material

Life of this patent

Abstract

Claims17