Method for the stabilization of polyvinylpyrrolidones
AssigneeBASF SE
InventorsKarl Kolter, Ivette Garcia Castro, Olga Pinneker, Ralf Widmaier, Karl-Hermann Strube, Bernhard Fussnegger, Manfred Kroll, Frank Höfer, Hermann Ascherl, Peter Schmidt
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Abstract
Method for stabilizing polyvinylpyrrolidones, which comprises treating the polyvinylpyrrolidones with sulfur dioxide, sulfurous acid or alkali metal sulfites and then with free-radical scavenger, and converting the solutions treated in this way into the powdered polyvinylpyrrolidones by drying.
Claims21
A method for stabilizing polyvinylpyrrolidones, comprising treating polyvinylpyrrolidone with sulfur dioxide, sulfurous acid or an alkali metal sulfite and subsequently with ascorbic acid or a salt thereof.
Dependencies are inferred from the claim text.