Gamma-radiation-resistant polycarbonate composition
AssigneeMiles Inc.
InventorsRick L. Archey, Robert J. Kumpf, Aaron D. Meltzer, Harald Pielartzik
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Abstract
A gamma radiation-resistant polycarbonate-disulfide resin is disclosed. The incorporation of disulfide linkages in the structure of polycarbonate was found to enhance the resistance of the resin to the discoloration caused by exposure to gamma radiation. Accordingly, processes for the incorporation of disulfide linkages in the molecular backbone, as end-groups or as side chains are disclosed. The polycarbonate-disulfide resin may be used as a molding resin in the context of thermoplastic molding compositions as well as a stabilizing additive in polycarbonate resin.
Claims8
A thermoplastic molding composition comprising a carbonate resin which has a weight average molecular weight of 500 to 100,000 and sulfur content of 0.002 to 2 percent, said resin containing at least one structural unit selected from the group consisting of ##STR6## where Ar, Ar' and R independently are aromatic radicals,
- p, n and m are integers and where their relative magnitude is determined by said sulfur content, said sulfur being derived from said disulfide structural units and said percent being relative to the weight of said resin.
Dependencies are inferred from the claim text.