Ultrahigh molecular weight polyethylene and lightly-filled composites thereof
AssigneeE. I. Du Pont de Nemours and Company
InventorsEdward G. Howard, Stuart M. Nemser
Life of this patent
Estimating the term…
Abstract
Homogeneous, particulate composites are provided, of about 75-99.5 weight percent ultrahigh molecular weight polyethylene (UHMWPE) and about 0.5-25 weight percent of at least one filler compound, and wherein the composites have a surface area of at least about 4 m.sup.2 /g. The particulate UHMWPE is also provided without the filler. Dense, load-bearing articles of these materials are formed by cold-pressing and free-sintering procedures. Cold-pressable, free-sinterable blends of commercial UHMWPE containing at least 25 weight percent of the composites or unfilled UHMWPE of the invention are also provided.
Claims25
A homogeneous, particulate, cold-pressable and free-sinterable composite comprising (a) about 75-99.5% by weight of ultrahigh molecular weight polyethylene having a molecular weight of at least 800,000 and (b) about 0.5-25% by weight of at least one finely-divided, filler compound having a neutral-to-acidic surface, in which substantially all of said polyethylene is polymerized onto the surface of said filler, and substantially all of said filler has polyethylene polymerized thereon, said composite having a surface area of at 1east about 4 m.sup.2 /g.
A non-fibrous, particulate, cold-pressable and free-sinterable ultrahigh molecular weight polyethylene having a molecular weight of at least 800,000 and a surface area of at least about 4 m.sup.2 /g, a bulk density of less than 0.2 g/ml, and an average particle size of at least 100 microns.
Dependencies are inferred from the claim text.