Expanded TFE copolymers, method of making and porous, expanded articles thereof
AssigneeW. L. Gore & Associates, Inc.
InventorLawrence A. Ford
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Abstract
A true tetrafluoroethylene (TFE) copolymer of the fine powder type is provided, wherein the copolymer contains polymerized comonomer units of at least one comonomer other than TFE in concentrations of at least or exceeding 1.0 weight percent, and which can exceed 5.0 weight percent, wherein the copolymer is expandable, that is, the copolymer may be expanded to produce strong, useful, expanded TFE copolymeric articles having a microstructure of nodes interconnected by fibrils. Articles made from the expandable copolymer may include tapes, membranes, films, fibers, and are suitable in a variety of end applications, including medical devices.
Claims24
A porous material having a microstructure of nodes interconnected by fibrils comprising an expanded core-shell tetrafluoroethylene (TFE) copolymer, said copolymer comprising:
- (a) a first, core portion comprising a polymer chain of TFE monomers and at least one comonomer;
- and
- (b) a second, shell portion consisting of a polymer chain consisting of TFE monomers,
- wherein said expandable core-shell tetrafluoroethylene copolymer comprises at least 3.0% by weight polymerized units of said at least one comonomer based on total weight of said copolymer,
- wherein said copolymer comprises a first melt transition temperature and a second melt transition temperature, and
- wherein said copolymer exhibits adhesion.
Dependencies are inferred from the claim text.