Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1993-06-01
1995-05-09
Schofer, Joseph L.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
422 22, 422 23, C08F 800
Patent
active
054140498
ABSTRACT:
A medical implant made of polymeric material having an increased oxidation resistance is formed by a method including the steps of placing a resin powder in a sealed container. A substantial portion of the oxygen is removed from the sealed container by either a vacuum, an oxygen absorbent or by flushing with inert gas. The container is then repressurized with a gas such as nitrogen, argon, helium or neon so that long term storage may be possible. On use, the resin is transferred to a forming device which both melts and forms the resin in an oxygen reduced atmosphere to produce a polymeric raw material such as a rod or bar stock. The medical implant is then formed from this raw material annealed and sealed in an airtight package in an oxygen reduced atmosphere. The implant is then radiation sterilized and thereafter annealed in the package for a predetermined time and temperature sufficient to form cross-links between any free radicals in neighboring polymeric chains.
REFERENCES:
patent: 3297641 (1967-01-01), Werber et al.
patent: 3352818 (1967-11-01), Meyer et al.
patent: 3758273 (1973-09-01), Johnston et al.
patent: 5037928 (1991-08-01), Li et al.
patent: 5153039 (1992-10-01), Porter et al.
patent: 5160464 (1992-11-01), Ward et al.
"Polypropylene Degradation by 2-Irradiation in Air" American Chemical Society, 1985, pp. 359-371.
"Radiation Effects on Polymers" American Chemical Society, 1991 (from symposium of Aug. 26-31, 1990) pp. 89-92.
"Radical Migration as an Elementary Process in Degradation" in Pure & Applied Chem., vol. 55, No. 10, pp. 1595-1601, 1983.
"Combined Chemical and Mechanical Effects on Free Radicals in UHMWPE Joints During Implantation", Journal of Biomedical-Materials Research, vol. 25, pp. 1005-1017, 1991.
Stark Casper F.
Sun Deh-Chuan
Akers Lawrence C.
Augustin Raymond W.
Howmedica Inc.
Richardson Peter C.
Schofer Joseph L.
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