| CPC C09D 5/022 (2013.01) [C08F 220/1808 (2020.02); C08K 3/22 (2013.01); C09D 7/61 (2018.01); C09D 133/064 (2013.01); C08K 2003/2241 (2013.01); C08K 2003/2296 (2013.01)] | 19 Claims |
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1. An aqueous polymer latex of a film-forming copolymer obtainable by aqueous emulsion polymerisation of monomers M, which comprise at least 80% by weight, based on the monomers M, of
at least one non-ionic monomer M1, which is selected from C1-C20-alkyl esters of acrylic acid, C5-C20-cycloalkyl esters of acrylic acid, C1-C20-alkyl esters of methacrylic acid, C5-C20-cycloalkyl esters of methacrylic acid, and monovinyl aromatic monomers; and
one or more monoethylenically unsaturated monomers M2, which are selected from monoethylenically unsaturated monocarboxylic acids having 3 to 6 carbon atoms and monoethylenically unsaturated dicarboxylic acids having 4 to 6 carbon atoms;
where the polymer latex contains an emulsifier combination comprising
i. at least one first emulsifier (1), which is selected from salts of sulfated ethoxylated C8-C20-alkanols having a degree of ethoxylation in the range from 5 to 20 and sulfated ethoxylated tristyrylphenols having a degree of ethoxylation in the range from 5 to 20; and
ii. at least one second emulsifier (2), which is selected from salts of a sulfated ethoxylated C8-C20-alkanol having a degree of ethoxylation in the range from 21 to 50 and sulfated ethoxylated tristyrylphenols having a degree of ethoxylation in the range from 21 to 50;
wherein the aqueous polymer latex comprises a first phase of a film-forming copolymer, which has a glass transition temperature Tg(1) in the range from −25 to +60° C. and a second phase of a film-forming copolymer, which has a glass transition temperature Tg(2) in the range from +50 to +150° C., provided that the absolute value of |Tg(2)−Tg(1)| is at least 10° C.
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