Stabilized gamma irradiated polyolefins
AssigneeCiba Specialty Chemicals Corporation
InventorRoswell E. King, III
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Abstract
Certain essentially phenol antioxidant-free stabilizer systems that comprise either a binary hindered amine/hydroxylamine or nitrone or amine oxide or benzofuranone system or a ternary hindered amine/hydroxylamine or nitrone or amine oxide or benzofuranone/organic phosphite or phosphonite system are especially effective towards protecting polyolefins against the deleterious effects of gamma irradiation. Polyolefin articles such as medical packaging, hospital garments, draperies, woven and non-woven fiber products, surgery utensils, blow-molded I.V. bottles, hypodermic syringes, needle shields, laboratory ware such as trays, funnels, Petri dishes and filters, and hygiene related articles may be sterilized with gamma irradiation and are stabilized according to the present invention.
Claims14
A polyolefin article of manufacture of improved strength and/or discoloration resistance, said article being essentially phenol antioxidant-free and having incorporated therein a stabilizer system sufficient to attenuate the deleterious effects of gamma irradiation, said stabilizer system consisting of
- (a) one or more hindered amine stabilizers,
- (b) one or more compounds selected from the group consisting of
- i.) hydroxylamine stabilizers and
- ii.) nitrone stabilizers and
- (c) one or more compounds selected from the group consisting of the organic phosphites and phosphonites,
- said article having been subjected to one or more doses of gamma irradiation and where the hindered amine stabilizers are selected from the group consisting of
A method for imparting strength and/or discoloration resistance to gamma irradiated polyolefin articles, which articles are essentially phenol antioxidant-free, which comprises incorporating therein a stabilizer system consisting of
- (a) one or more hindered amine stabilizers,
- (b) one or more compounds selected from the group
- i.) hydroxylamine stabilizers and
- ii.) nitrone stabilizers and
- (c) one or more compounds selected from the group consisting of the organic phosphites and phosphonites,
- in an amount sufficient to attenuate the deleterious effects of gamma irradiation and where the hindered amine stabilizers are selected from the group consisting of
Dependencies are inferred from the claim text.