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US 5,512,629 AGranted
Aqueous polymer dispersions
AssigneeBASF SE
InventorsWilhelm F. Beckerle, Rolf Petri, Bernhard Dotzauer, Manfred Schwartz, Maximilian Angel
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Abstract
Aqueous dispersions of polymers which have a high glass transition temperature and a low average molecular weight and contain a specific amount of methacrylic acid as polymerized units are suitable, in liquid or dried form, as additives for improving the flow behavior of cement-containing mineral building materials having binding properties.
Claims16
A mineral building material comprising:
- a cement-containing mineral binder, and a polymer dispersion in aqueous or dried form, wherein
- said polymer dispersion is obtained by polymerizing a monomer mixture comprising
- (a) from 70 to 85% by weight of at least one monomer selected from the group consisting of styrene, vinyltoluenes, nitriles of .alpha.,.beta.-monoethylenically unsaturated carboxylic acids of 3 to 6 carbon atoms and esters of .alpha.,.beta.-monoethylenically unsaturated carboxylic acids of 3 to 6 carbon atoms and alkanols of 1 to 12 carbon atoms
- (b) from 15 to 25% by weight of at least one .alpha.,.beta.-monoethylenically unsaturated carboxylic acid of 3 to 6 carbon atoms of amides thereof and
- (c) from 0 to 5% by weight of other copolymerizable monomers
- by aqueous free radical emulsion polymerization with the proviso that
- component (b) comprises at least 50% by weight, based on the total amount of component (b), of methacrylic acid;
- and that components (a) , (b) and (c) chosen so that a glass transition temperature of the resulting polymer is from 80.degree. to 160.degree. C. according to the Fox relationship for an emulsion polymer composed of these components;
- and that the K value of the resulting emulsion polymer, determined in its fully acidic form in dimethylformamide at 23.degree. C. and an emulsion polymer content of 0.1% by weight, being from 15 to 40, and wherein said aqueous polymer dispersion is optionally dried.
6 more elements
A mineral binding material comprising
- a cement-containing mineral binder and a polymer powder, and wherein said polymer powder is obtained by polymerizing a monomer mixture comprising
- (a) from 70 to 85% by weight of at least one monomer selected from the group consisting of styrene, vinyltoluenes, nitriles of .alpha.,.beta.-monoethylenically unsaturated carboxylic acids of 3 to 6 carbon atoms and esters of .alpha.,.beta.-monoethylenically unsaturated carboxylic acids of 3 to 6 carbon atoms and alkanols of 1 to 12 carbon atoms,
- (b) from 15 to 25% by weight of at least one .alpha.,.beta.-monoethylenically unsaturated carboxylic acid of 3 to 6 carbon atoms of amides thereof and
- (c) from 0 to 5% by weight of other copolymerizable monomers,
- with the proviso that
- the component (b) comprises at least 50% by weight, based on the total amount of component (b), of methacrylic acid;
- and that components (a), (b) and (c) chosen so that a glass transition temperature of the resulting polymer is from 80.degree. to 160.degree. C. according to the Fox relationship for a polymer composed of these components;
- and that the K value of the polymer, determined in its fully acidic form in dimethylformamide at 23.degree. C. and a polymer content of 0.1% by weight, being from 15 to 40.
5 more elements
Dependencies are inferred from the claim text.