Preparation of polymer powders
AssigneeBASF SE
InventorsJoachim Pakusch, Markus Koppers, Wolfgang Gaschler, Heinrich Sack, Juergen Schmidt-Thuemmes, Hans-Juergen Denu
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Abstract
A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.
Claims20
A process for preparing a polymer powder comprising evaporating volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein, prior to the evaporation of the volatile constituents, the aqueous polymer dispersion comprises a drying assistant T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, wherein the drying assistant T is polyvinylformamide.
A mineral binding construction material in the form of a dry mortar formulation, consisting of
- from 10 to 60% by weight of mineral binder;
- from 0.1 to 30% by weight of polymer powder obtained by evaporating volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein, prior to the evaporation of the volatile constituents, said aqueous polymer dispersion comprises a drying assistant T, present in an amount ranging from 0.1 to 80% by weight, based on the polymer P of the dispersion, said drying assistant T is polyvinylformamide, or an addition polymer powder comprising i) at least one film-forming polymer P, and ii) from 0.1 to 80% by weight, based on the polymer P, of polyvinylformamide as drying assistant T;
- no greater than 25% by weight of an auxiliary customary for mineral binding construction materials;
- and
- in remainder, an aggregate selected from the group consisting of sand, a filler, a pigment, a natural fiber, a synthetic fiber, and a combination thereof.
Dependencies are inferred from the claim text.