AQUEOUS BINDER SYSTEMS AND THEIR USE IN PRODUCING COATING COMPOSITIONS
A binder mixture is described comprising: an aqueous copolymer dispersion which has a glass transition temperature, T g , of less than 10° C. and which is prepared by emulsion polymerization of a monomer mixture comprising: (i) at least 60% by weight, based on the total amount of monomers, of at least one vinyl ester; (ii) from 15 to 30% by weight, based on the total amount of monomers, of ethylene; (iii) from 0.05 to 5% by weight, based on the total amount of monomers, of an ethylenically unsaturated carboxylic acid having at least 4 carbon atoms; and (iv) from 0.05 to 5% by weight, based on the total amount of monomers, of an ethylenically unsaturated sulfonic acid or salt thereof.
1 . An aqueous binder mixture comprising:
(A) an aqueous copolymer dispersion which has a glass transition temperature, T g , of less than 10° C. and which is prepared by emulsion polymerization of a monomer mixture comprising:
(i) at least 60% by weight, based on the total amount of monomers, of at least one vinyl ester;
(ii) from 15 to 30% by weight, based on the total amount of monomers, of ethylene;
(iii) from 0.05 to 5% by weight, based on the total amount of monomers, of an ethylenically unsaturated carboxylic acid having at least 4 carbon atoms; and
(iv) from 0.05 to 5% by weight, based on the total amount of monomers, of an ethylenically unsaturated sulfonic acid or salt thereof.
2 . The binder mixture of claim 1 , wherein the at least one vinyl ester comprises vinyl acetate.
3 . The binder mixture of claim 1 and comprising from 18 to 30% by weight, based on the total amount of monomers, of ethylene.
4 . The binder mixture of claim 1 and comprising from 20 to 25% by weight, based on the total amount of monomers, of ethylene.
5 . The binder mixture of claim 1 and comprising from 0.2 to 1.5% by weight, based on the total amount of monomers, of said ethylenically unsaturated carboxylic acid having at least 4 carbon atoms.
6 . The binder mixture of claim 1 and comprising from 0.2 to 1.5% by weight, based on the total amount of monomers, of said ethylenically unsaturated sulfonic acid or salt thereof.
7 . The binder mixture of claim 1 , wherein the ethylenically unsaturated carboxylic acid comprises crotonic acid.
8 . The binder mixture of any claim 1 , wherein the ethylenically unsaturated sulfonic acid has 2 to 8 carbon atoms.
9 . The binder mixture of claim 1 , wherein the ethylenically unsaturated sulfonic acid comprises vinyl sulfonic acid.
10 . The binder mixture of claim 1 , wherein the aqueous copolymer dispersion further comprises (v) up to 1% by weight, based on the total amount of monomers, of an unsaturated silane comonomer.
11 . The binder mixture of claim 1 , wherein the aqueous copolymer dispersion further comprises (v) from 0.1 to 0.5% by weight, based on the total amount of monomers, of an unsaturated silane comonomer.
12 . The binder mixture of any claim 1 and further comprising:
(B) at least 0.05% by weight, based on the total amount of monomers, of a cellulose-based stabilizer.
13 . The binder mixture of claim 12 , wherein the cellulose-based stabilizer comprises hydroxyethyl cellulose.
14 . The binder mixture of any claim 1 and further comprising:
(B) from 0.2 to 3% by weight, based on the total amount of monomers, of a cellulose-based stabilizer.
15 . The binder mixture of claim 14 , wherein the cellulose-based stabilizer comprises hydroxyethyl cellulose.
16 . A coating composition comprising:
(a) aqueous binder mixture of claim 1 ;
(b) at least one solids component selected from a filler and a pigment; and
(c) at least one auxiliary component selected from the group consisting of wetting agents, dispersants, emulsifiers, fillers, thickeners, defoamers, dyes and preservatives.
17 . A paint formulation comprising the coating composition of claim 16 .