Patent ID: 7964677

Claim:
A method of changing from a polymerization using a first catalyst to a polymerization using a second catalyst which is incompatible with the first catalyst in a gas-phase reactor, said method comprising: a) stopping the polymerization reaction using the first catalyst; b) flushing the reactor under polymerization conditions with at least one deactivating agent comprising a volatile component selected from an organic compound or a mixture of organic compounds comprising at least one functional group selected from the group consisting of —OR, —NR2, —SR, ═O, and ═S, wherein R is hydrogen or a C 1 -C 6 -alkyl, and a nonvolatile component in a weight ratio of from 0.1 to 1000; c) introducing the second catalyst into the reactor; and d) continuing the polymerization using the second catalyst, wherein the nonvolatile component comprises at least a polymeric amine, a polymeric amide, a polyamine, a polyamine copolymer or a polysulfone copolymer.