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. 30, 2004
Filed:
Nov. 19, 2001
Robert H. Gore, Southampton, PA (US);
Bridget M. Stevens, Horsham, PA (US);
Rohmax Additives GmbH, Darmstadt, DE;
Abstract
A method for making a viscosity index improving copolymer includes heating a reaction mixture including from about 55 weight percent to about 99.5 weight percent of a first monomer selected from the group consisting of (C -C )alkyl (meth)acrylates and mixtures thereof, from about 0.5 weight percent to about 45 weight percent of a second monomer selected from the group consisting of (C -C )alkyl (meth)acrylates, (C -C )alkyl(meth)acrylates and mixtures thereof, a polymerization initiator and a hydrocarbon diluent, to a reaction temperature from about 75° C. to about 100° C. and maintaining the reaction mixture at the reaction temperature for a period of time effective to allow copolymerization of the monomers.