The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 03, 2002
Filed:
Nov. 02, 2000
Vu A. Dang, Bear, DE (US);
Cheng Q. Song, Wilmington, DE (US);
Basell Poliolefine Italia S.p.A., Milan, IT;
Abstract
Graft copolymers with low molecular weight side chains are prepared by (1) irradiating a propylene polymer material in the absence of oxygen, (2) adding a controlled amount of oxygen to the irradiated polymer material so that the polymer is exposed to an amount of oxygen greater than 0.004% but less than 15% by volume at a temperature of 40° C. to 140° C., to produce an oxidized propylene polymer material containing greater than 1 mmol total peroxide per kilogram of propylene polymer material, (3) optionally, heating the oxidized propylene polymer material in a non-oxidizing atmosphere to a temperature of at least 80° C. but below the softening point of the polymer, and (4) treating the oxidized propylene polymer material in a non-oxidizing atmosphere with at least one grafting monomer that is capable of being polymerized by free radicals, in the presence of at least one additive to control the molecular weight of the side chains of the polymerized grafting monomer selected from (a) at least one hydroxylamine derivative polymerization inhibitor, and (b) at least one thio-, nitro-, or halogen-substituted aliphatic or aromatic compound, or an aliphatic or aromatic phosphine derivative, and (5) deactivating the residual free radicals in the resulting grafted propylene polymer material and removing any unreacted vinyl monomer from the material.