METHOD FOR FRACTIONAL SEPARATION OF LIQUID CONTAINING ACRYLIC ACID AND/OR METHACRYLIC ACID Russian patent published in 2011 - IPC C07C51/44 C07C57/75 C08F20/06 C07C51/42 C07C57/04 C07C51/50 

FIELD: chemistry.

SUBSTANCE: content of acrylic aid or methacrylic acid in the liquid per total weight of liquid II is at least 10 wt %, where, along with methacrylic acid and/or acrylic acid, said liquid also contains acrolien and/or methacrolein, as well as acetone in total amount of not more than 5 wt % per total content of acrylic acid and/or methacrylic acid in liquid II, provided that liquid II was produced without adding acrolen or methacrolein in form of a pure substance of another liquid I containing acrylic acid and/or methacrylic acid, wherein liquid II, in which the weight ratio of acrolien to acetone contained therein is not equal to 3.5, liquid II is fed into the fractionation column provided that it contains at least 10 wt % acetone which inhibits polymerisation of acrylic and/or methacrylic acid, in terms of acrolein and methacrolein contained in liquid II.

EFFECT: less susceptibility of acrylic acid or methacrylic acid to polymerisation during fractional separation of liquid II.

8 cl, 3 tbl, 3 ex