Graft copolymers of polyolefins and a method of producing same
AssigneeMontell North America Inc.
InventorsPaolo Galli, Anthony J. DeNicola, Jr., Jeanine A. Smith
Life of this patent
Estimating the term…
Abstract
Disclosed are graft copolymers of polyolefins and a method of preparing the graft copolymers. The method includes irradiating a mass of olefin polymer particles and thereafter treating the mass of particles with a vinyl monomer in liquid form. A nonoxidizing environment is maintained throughout the process while free radicals produced in the olefin polymer by the irradiation are present, thereby preventing degradation of the polymer. In a final step, residual free radicals are deactivated, and any unreacted monomer is removed.
Claims11
A method of making a graft copolymer of an olefin polymer comprising the steps of:
- (a) irradiating a particulate olefin polymer material at a temperature in the range of about from 10.degree. to 85.degree. C. with high-energy ionizing radiation to produce free radical sites without causing gelation of the particulate olefin polymer material;
- (b) treating the irradiated particulate olefin polymer material at a temperature up to about 100.degree. C. for a period of at least about 3 minutes, with about from 5 to 80 percent by weight, based on the total weight of olefin polymer and vinyl monomer used, of at least one vinyl monomer capable of being polymerized by free radicals;
- (c) simultaneously or successively in optional order,
- (1) beating the resultant grafted particulate olefin polymer material to a temperature of at least 110.degree. C., thereby deactivating substantially completely all residual free radicals therein, and
- (2) removing any unreacted vinyl monomer from said material;
- the particulate olefin polymer material being maintained in a substantially non-oxidizing environment throughout steps (a) to (c) at least until after the deactivation of residual free radicals has been completed.
Dependencies are inferred from the claim text.