PROCESS FOR THE PREPARATION OF A PURIFIED ACRYLAMIDO SULFONIC ACID MONOMER DERIVATIVE

摘要

A process for the preparation of a purified monomer is disclosed which comprises the steps of reacting an impure monomer (A) wherein R1 and R2 are independently hydrogen or alkyl groups containing from 1 to about 6 carbon atoms, with (B) a substantially aqueous solution of an oxide or hydroxide of the structure MO or MOH wherein M is a Group IA or Group IIA metal, or an amine of the structure NR3R4R5 wherein R3, R4 and R5 are independently hydrogen or alkyl, alkanol or alkoxy groups containing from 1 to about 12 carbon atoms, wherein the molar ratio of (A):(B) is from about 1:1-2 for Group IA metals, 2:1-2 for Group IIA metals or ratio of moles of (A) to nitrogens of (B) is from about 1:1-2 nitrogens to form a salt, and recovering a purified salt by crystallization by subjecting the aqueous solution to changes in temperature and/or pressure and/or concentration.