Use of polymers as filtering aids and/or stabilizers
AssigneeBASF SE
InventorsCHRISTIAN DROHMANN, Helmut Witteler, Axel Sanner, Jürgen Ziehl, Elisa Hamm De Bantleon, Tobias Petsch, Klemens Mathauer, Barbara Lebtig
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Abstract
The use of polystyrene-containing polymers as filter aids and/or stabilizers for the filtration or stabilization of aqueous liquids, and also novel particulate polymers which are insoluble in water and scarcely swellable are claimed.
Claims20
1-21. (canceled)
A filter aid for filtering and stabilizing an aqueous liquid, the filter aid comprising a comminuted form of a compounded polymer obtained by reactive compounding of
- a) 20-95% by weight of polystyrene;
- and
- b) 80-5% by weight of PVPP
- wherein the reactive compounding is selected from the group consisting of rolling, kneading, casting, sintering, pressing, compounding, calandering, extrusion or combination thereof.
A process for preparing a filter aid for filtering and stabilizing an aqueous liquid, the process comprising reactive compounding 20-95% by weight of polystyrene and 80-5% by weight of PVPP, optionally together with further added substances, and comminuting the compounded product wherein the reactive compounding is selected from the group consisting of rolling, kneading, casting, sintering, pressing, compounding, calandering, extrusion or combination thereof.
A polymer composition comprising a compounded mixture of 20-95% by weight of polystyrene and 80-5% by weight of PVPP and optionally at least one additional substance selected from the group consisting of alkali metal carbonates, alkali earth metal carbonates, alkali metal hydrogen carbonates, alkali earth metal hydrogencarbonates, oxides of subgroup 4 of the Periodic Table of the Elements, oxides of main group 3 of the Periodic Table of the Elements, mixed oxides of subgroup 4 of the Periodic Table of the Elements, mixed oxides of main group 3 of the Periodic Table of the Elements, polyamides, crosslinked polyvinylactams, polyvinylamines, and mixtures thereof, wherein the compounded mixture is prepared by reactive compounding of said polystyrene, PVPP and at least one optional substance, and the reactive compounding is selected from the group consisting of rolling, kneading, casting, sintering, pressing, compounding, calandering, extrusion or combination thereof.
Dependencies are inferred from the claim text.