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:
Feb. 01, 1983
Filed:
Mar. 20, 1981
Basf Aktiengesellschaft, Ludwigshafen, DE;
Abstract
Aqueous polymer dispersions containing up to 75% by weight of polymer are prepared advantageously by emulsion copolymerization in the presence of conventional anionic emulsifiers, polymerization initiators and small amounts of polymerization inhibitors, at conventional polymerization temperatures, by copolymerizing at least two monomers A, which per se are not copolymerizable with one another, mixed with from 60 to 95% by weight of at least one monomer B, which is copolymerizable with both monomers A, in the presence of a polymerization inhibitor, by the emulsion feed process, wherein (a) the initial aqueous phase at the start of the monomer emulsion feed contains from 0.01 to 0.5% by weight of anionic emulsifier and from 1 to 7% by weight of water-soluble salts, (b) the monomer emulsion contains from 50 to 500 ppm of polymerization inhibitor, (c) from 1 to 10% by weight of the monomer emulsion is added, within the first 1/2 hour from the start of the feed, at an increasing rate per unit time, to the initial charge and thereafter (d) the remaining monomer emulsion is added in a conventional manner in accordance with the rate of polymerization of the monomers.