Patent ID: 7060769
Filing Date: 2006-06-13
Classification: C08G

Abstract:
1. A method of curing a composition by a metathesis reaction, comprising the steps of: (a) mixing an olefin-containing substrate, a metal carbene complex catalyst and a reaction control agent at a mixing temperature to form a mixture, wherein the catalyst is effective to initiate the metathesis reaction upon mixing, and wherein the reaction control agent is present in an amount sufficient to slow the progress of the metathesis reaction and to prevent the metathesis reaction from proceeding to completion in the absence of an elevated temperature above the mixing temperature, and wherein the olefin-containing substrate comprises at least one oligomer or polymer having a backbone of >50% linear siloxane units, the oligomer or polymer functionalized with olefin groups curable by the metathesis reaction, and wherein the at least one oligomer or polymer is selected from the group consisting of: a telechelic oligomer or polymer end-capped with the olefin groups, an oligomer or polymer tethered and end-capped with the olefin groups, a tri-functional oligomer or polymer end-capped with the olefin groups, and a quadri-functional oligomer or polymer end-capped with the olefin groups, and combinations thereof, and wherein the metal carbene complex catalyst has the structure:  wherein: M is ruthenium or osmium, X is an alkylidene ligand with basicity higher than that of tricyclohexylphosphine (PCy X X R wherein the reaction control agent is selected from the group consisting of: 1) modified hydrocarbons containing at least one heteroatom selected from Group 14 and 15 of the periodic table, and optionally containing one or more oxygen atoms, sulfur atoms, or both, and wherein the at least one heteroatom is optionally bonded to one or more hydrocarbon fragments containing a double or triple bond, and 2) hydrocarbons containing one or more double or triple bond functional groups, and optionally containing or more oxygen atoms, sulfur atoms, or both; and (b) prior to deactivation of the catalyst, exposing the mixture to the elevated temperature of at least 30° C. greater than the mixing temperature to accelerate the rate of the metathesis reaction to allow the reaction to proceed toward completion.