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:
Aug. 04, 1981
Filed:
Aug. 06, 1979
Rainer Benda, Rossdorf, DE;
Helmuth Knoell, Lautertal, DE;
Peter Neudoerfl, Darmstadt-Neu-Kranichstein, DE;
Horst Pennewiss, Darmstadt-Neu-Kranichstein, DE;
Rohm GmbH, Darmstadt, DE;
Abstract
What is disclosed is a method for making a lubricating oil additive which comprises a first step of graft copolymerizing an alkyl ester of acrylic acid or of methacrylic acid, alone or in combination with styrene, onto a backbone copolymer which is hydrogenated block copolymer of styrene and a conjugated diene having 4 to 6 carbon atoms to form a first graft copolymer, and a second step of graft copolymerizing a polymerizable heterocyclic monomer, alone or in combination with a hydrophobizing vinyl ester, onto said first graft copolymer to form a second graft copolymer, and the lubricating oil additive so made.