Patent EA-001419-B1 (EA)
Title: Water-redispersible powders of film-forming polymers prepared from ethylenically unsaturated monomers
Inventor: BETT WILLIAM
IPC: C09D157/06
Filed: 1997-01-08
Abstract: 1. A water-redispersible powder composition comprising: (a) 100 parts by weight of a powder consisting of a water-insoluble film-forming polymer prepared from at least one ethylenically unsaturated monomer and at least one monomer selected from monomers having a carboxylic function and acrylamide or methacrylamide, and (b) 2-40 parts by weight and preferably 8-22 parts by weight of at least one amino acid or a salt thereof. 2. A powder composition according to claim 1, characterized in that ethylenically unsaturated monomer is selected from styrene, butadiene, C1-C12 alkyl esters of acrylic or methacrylic acids, acrylic or methacrylic acids or vinylic esters. 3. A powder composition according to claim 1 or 2, characterized in that a monomer having a carboxylic function is selected from ethylenically unsaturated carboxylic acids. 4. A powder composition according to claim 3, characterized in that ethylenically unsaturated carboxylic acids are selected from the group comprising fumaric acid, itaconic acid, crotonic acid, maleic acid, maleic anhydride, mesaconic acid, glutaconic acid, or a muxture thereof. 5. A powder composition according to one of the preceding claims, characterized in that water-insoluble polymer is prepared from a mixture of monomers, comprising 99,9-92% by weight of at least one ethylenically unsaturated monomer and 0,1-8% by weight of at least one monomer having carboxylic function. 6. A powder composition according to one of the preceding claims, characterized in that an amino acid is selected from: - monoamino monocarboxyl acids, - monoamino dicarboxyl acids, - diamino monocarboxyl acids. 7. A powder composition according to one of the preceding claims, characterized in that the amino acid is selected from glycine, alanine, leucine, phenylalanine, aspartic acid, glutamic acid, hydroxyglutamic acid, arginine, lysine, histidine, cystine. 8. A powder composition according to one of the preceding claims, characterized in that an amino acid salt is hydrosoluble or hydroalcalisoluble. 9. A powder composition according to one of the preceding claims, characterized in that the composition comprises at least one water-hydrosoluable composition (C) selected from polyelectrolytes related to the family of faint polyacids. 10. A powder composition according to one of the preceding claims, characterized in that the composition comprises a powder-like mineral filler (d) with particles less than 20 μm. 11. A method for preparing water-redispersible powder according to one of the preceding claims by eliminating water from polymer emulsions, characterized in that water is eliminated from the polymer emulsion, prepared from, at least one ethylenically unsaturated monomer and, at least one monomer, selected from a monomer having carboxylic function, and acrylamide or methacrylamide, and comprising, at least, one amino acid or one salt thereof and atomizing dry residue to obtain the powder of the desired granulometric composition. 12. The method according to claim 11, characterized in that a mineral filler or a part thereof is added at the stage of atomizing. 13. Pseudo-latex obtained by a redispersion of powder composition in water according to one of claims 1 to 10. 14. Use of pseudo latexes according to claim 13 as additives to aqueous binders, adhesives, compositions for paper lamination and to dyes. 15. Use of powder compositions according to claims 1 to 10 as additives to aqueous binders, adhesives, compositions for paper lamination and to dyes.