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:
Mar. 26, 1991
Filed:
May. 21, 1990
Mohammed Tazi, Wayne, NJ (US);
John J Ardan, Butler, NJ (US);
GAF Chemicals Corporation, Wayne, NJ (US);
Abstract
What is described herein is a process for making copolymers of maleic anhydride and C.sub.1 -C.sub.4 alkyl vinyl ethers of predetermined specific viscosities extending over a wide viscosity range. The invention is characterized by (a) precharging a reactor with a C.sub.1 -C.sub.4 alkyl vinyl ether as solvent and a polymerization initiator at a reaction temperature, (b) feeding a mixture of maleic anhydride and a C.sub.1 -C.sub.4 alkyl vinyl ether in substantially stoichiometric amounts, preferably with a slight excess of alkyl ether, and at a selected rate, into said precharged reactor, (c) polymerizing said reactants to form a slurry of said copolymer in said escess alkyl vinyl ether solvent, and (d) introducing toluene into said reactor during the polymerization to control the specific viscosity of the copolymer product being produced.