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. 27, 2024
Filed:
Feb. 27, 2020
Celanese International Corporation, Irving, TX (US);
Kerstin Wenzel, Wiesbaden-Delkenheim, DE;
Narayan Raman, Cincinnati, OH (US);
Tsz Ming Tsang, Cincinnati, OH (US);
James Martin, Lake Side Park, KY (US);
Celanese International Corporation, Irving, TX (US);
Abstract
An aqueous copolymer dispersion is obtained by a multi-stage emulsion polymerization process comprising polymerizing in a reaction zone in a first polymerization stage a first monomer composition comprising at least 88 wt % of a vinyl ester of a Cto Ccarboxylic acid and up to 12 wt % ethylene to produce a first stage polymer having Tg>20° C.; and polymerizing in the reaction zone, in a second polymerization stage and in the presence of the first stage polymer, a second monomer composition comprising a vinyl ester of a Cto Ccarboxylic acid and a Cto Calkyl ester of (meth)acrylic acid to produce a second stage polymer having Tg≤20° C. Each of the polymerization stages is conducted in the presence of a stabilizing system comprising at least 0.1 wt % of a protective colloid and at least 0.05 wt % of an ionic surfactant.