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. 27, 2007
Filed:
Sep. 30, 2002
Lambertus Manders, Ludwigshafen, DE;
Thomas Wirth, Freinsheim, DE;
Wolfgang Gaschler, Heidelberg, DE;
Hubertus Kroener, Neustadt, DE;
Lambertus Manders, Ludwigshafen, DE;
Thomas Wirth, Freinsheim, DE;
Wolfgang Gaschler, Heidelberg, DE;
Hubertus Kroener, Neustadt, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A process for preparing an aqueous styrene-butadiene polymer dispersion by free-radical aqueous emulsion polymerization of a monomer mixture M containing from 40 to 80% by weight of styrene as monomer M1, from 20 to 60% by weight of butadiene as monomer M2, and from 0 to 40% by weight, based on 100% by weight of monomers, of ethylenically unsaturated comonomers M3 other than styrene and butadiene by a monomer feed technique in the presence of from 0.05 to 0.5% by weight, based on 100% by weight of monomers, of at least one hydrocarbon HC having 6 to 20 carbon atoms selected from compounds which on abstraction of a hydrogen atom form a pentadienyl radical or a 1-phenylallyl radical and α-methylstyrene dimer comprises raising, at a point in time when at least 70% of the monomers to be polymerized have been supplied to the polymerization reaction, the concentration of butadiene in the monomer feed for a period of at least 1% of the total feed time by at least 10% by weight, based on monomers in the feed.