公开(公告)号：US11440978B2

公开(公告)日：2022-09-13

申请号：US17250136

申请日：2019-05-30

申请人： CELANESE INTERNATIONAL CORPORATION

发明人： Kerstin Wenzel ,  Matthias Junk ,  Thomas Fichtner ,  Stephan Krieger

IPC分类号： C08K3/013 ,  C08F220/06 ,  C08F2/22 ,  C08F218/08 ,  C08F218/10 ,  C08F220/14 ,  C08F230/08 ,  C08F220/18 ,  C08F2/00 ,  C09D5/02

摘要： A multistage emulsion polymerization process comprises polymerizing a first monomer composition comprising from 50 to 95 weight percent of vinyl acetate, from 5 to 40 weight percent of at least one vinyl ester of a C5 to C18 unsaturated carboxylic acid, and optionally up to 40 weight percent of ethylene, all based on the total weight of monomers in the first monomer composition, to produce a first stage polymer. A second monomer composition comprising 40 to 89.95 weight percent of at least one ester of methacrylic acid or a vinyl aromatic monomer, 10 to 59.95 weight percent of at least one ester of acrylic acid, and from 0.05 to 10 weight percent of at least one comonomer with acid functionality, based on the total weight of monomers in the second monomer composition, is then polymerized in the presence of the first stage polymer to produce a second stage polymer.

公开(公告)号：US12071496B2

公开(公告)日：2024-08-27

申请号：US17435129

申请日：2020-02-27

申请人： CELANESE INTERNATIONAL CORPORATION

发明人： Kerstin Wenzel ,  Narayan Raman ,  Tsz Ming Tsang ,  James Martin

IPC分类号： C08F210/02 ,  C08F2/00 ,  C08F2/20 ,  C08F2/26 ,  C08F2/30 ,  C08F218/08 ,  C08F220/18 ,  C09D5/02 ,  C09D7/65

CPC分类号： C08F220/1804 ,  C08F2/001 ,  C08F2/20 ,  C08F2/26 ,  C08F2/30 ,  C08F210/02 ,  C08F218/08 ,  C09D5/022 ,  C09D7/65

摘要： 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 C1 to C18 carboxylic 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 C1 to C18 carboxylic acid and a C2 to C8 alkyl 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.