Method for obtaining pure n-vinyl pyrrolidone
AssigneeBASF SE
InventorsBernd Eck, Jorg Heilek, Martin Schmidt-Radde, Herbert Helfert
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Abstract
The invention describes a process for the isolation of pure N-vinylpyrrolidone from N-vinylpyrrolidone-containing crude products, comprising a single-stage or multistage crystallization process, which comprises passing the mother liquor from the first crystallization stage either to a distillative and/or extractive purification, or returning it to an N-vinylpyrrolidone-containing product stream of the preparation process.
Claims8
A process for the isolation of pure N-vinylpyrrolidone from N-vinylpyrrolidone-containing crude products, comprising a single-stage or multistage crystallization process, which comprises passing the mother liquor from the first crystallization stage either to a distillative and/or extractive purification, or returning it to an N-vinylpyrrolidone-containing product stream of the preparation process.
A process as claimed in any of the preceding claims, wherein the crystallization is carried out in a single stage.
A process as claimed in any of the preceding claims, wherein the crystallization is carried out in the presence of seed crystals of N-vinylpyrrolidone.
Dependencies are inferred from the claim text.