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:
May. 22, 1979
Filed:
May. 09, 1977
Ervin G Pritchett, Cincinnati, OH (US);
National Distillers and Chemical Corporation, New York, NY (US);
Abstract
A process for toughening ethylene-vinyl acetate copolymers is disclosed which comprises reacting a rubbery ethylene-vinyl acetate copolymer with oxygen at elevated temperature in the presence of a catalytically effective amount of at least one catalyst selected from the group consisting of an alkali metal, ammonium or zinc salt of a weak aliphatic carboxylic acid, an alkali metal, ammonium or zinc salt of a weak aromatic carboxylic acid, an aliphatic tertiary amine, and an aromatic tertiary amine, for a period sufficient to provide an ethylene-vinyl acetate copolymer demonstrating an appreciable increase in melt viscosity as indicated by a corresponding decrease in melt flow rate compared with that of the starting copolymer.