Process for preparation of highly pure, non-yellowing methacrylic acid

摘要

This invention relates to a process of preparing highly pure, non-yellowing (meth)acrylic acid necessary for high-tech applications requiring long-tem color stability in the presence of amines. Process for the preparation of highly pure, non-yellowing (meth)acrylic acid comprising the steps: f) Condensation of a (meth)acrylic acid-containing gas phase obtained via a gas phase oxidation process of a C4-compound to generate an aqueous (meth)acrylic acid solution g) Separation of the (meth)acrylic acid from the aqueous (meth)acrylic acid solution to obtain crude (meth)acrylic acid h) Rectification of the crude (meth)acrylic acid to obtain pure (meth)acrylic acid via a sidestream outlet of the rectification column i) Treatment of the pure (meth)acrylic acid generated in step c) with an ion exchange resin j) Distillation of the (meth)acrylic acid generated in step d).

主权项

1. A process for preparing highly pure, non-yellowing (meth)acrylic acid, comprising:
a) condensing a (meth)acrylic acid-containing gas phase obtained via a gas phase oxidation process of a C4-compound to generate an aqueous (meth)acrylic acid solution; b) separating the (meth)acrylic acid from the aqueous (meth)acrylic acid solution to obtain crude (meth)acrylic acid; c) rectifying the crude (meth)acrylic acid in a rectification column to obtain pure (meth)acrylic acid via a sidestream outlet of the rectification column; d) treating the pure (meth)acrylic acid generated in c) with an ion exchange resin; and e) distilling the (meth)acrylic acid generated in d).