Patent ID: 6812302
Filing Date: 2004-11-02
Classification: C08F

Abstract:
A process for preparing a liquid rubber composition for a cured thermoset resin, wherein said liquid rubber composition is characterized as being miscible in the uncured state of said thermoset resin and immiscible in the cured state of said thermoset resins, said liquid rubber composition comprising polymer chains having at least one non-functional aromatic terminal end-group, a weight average molecular weight of at least 1069 g/mol, a glass transition temperature less than âˆ’40Â° C., the process comprising the steps of:(a) forming a reaction mixture, said reaction mixture comprising: (i) from 1.0 to 99.999 weight percent of the reaction mixture of at least one C1-C20 alkyl acrylate monomer; and (ii) from 0.001 to 20 weight percent of the reaction mixture of at least one aromatic-containing initiator selected from the group consisting of alkyl-substituted diphenyl compounds having the following general structure: Phâ€”(CR3R4)â€”(CR5R6)â€”Ph, wherein Ph are separately phenyl groups, and R3, R4, R5, and R6 each represent a hydrogen or an alkyl group, at least two of R3, R4, R5, and R6 being alkyl groups, and the phenyl groups are unsubstituted or contain alkyl substituents;(b) charging the reaction mixture into a reactor maintained at a reaction temperature of from 200Â° C. to 300Â° C.; (c) initiating polymerization of said monomer with said aromatic-containing initiator to form a reaction product containing said polymer chains; and (d) providing a reaction residence time sufficient for the polymer chains to form.