Patent ID: 7638091

Claim:
A method comprising treating an article with steam, wherein the article comprises a composition comprising an amount of a polysiloxane-polycarbonate copolymer and a copolyester polycarbonate copolymer effective to provide thermal and hydrolytic stability to the article for at least 15 cycles, wherein each cycle comprises 20 minutes of contact with steam at a temperature of 100° C., at atmospheric pressure wherein the polysiloxane-polycarbonate copolymer consists of units derived from a polycarbonate block and a polydiorganosiloxane block and optionally a chain termination agent wherein the copolyester polycarbonate copolymer comprises repeating structural carbonate units of formula (1): and repeating structural ester units of formula (6): where at least 60 percent of the total number of R 1 groups are aromatic organic radicals and the balance thereof are aliphatic, alicyclic or aromatic radicals and D is a divalent radical derived from a dihydroxy compound and T is a divalent radical derived from a dicarboxylic acid.