PURPOSE: To obtain a highly concentrated, highly pure polystyrenesulfonic acid economically in good efficiency, by passing a highly concentrated aqueous polystyrenesulfonate salt solution through an ion exchange resin tower at a velocity corresponding to at least a specified space velocity.
CONSTITUTION: An ion exchange resin tower is packed with a cation exchange resin having a styrene/divinylbenzene copolymer as a matrix. An aqueous polystyrenesulfonate salt solution of a concentration ≥10wt% is fed to this tower and passed therethrough at a space velocity ≤5 to obtain the purpose polystyrenesulfonic acid. Generally, a polystyrenesulfonate salt contains inorganic impurities such as halides and sulfates, so that it is preferable to treat it with an anionic ion exchange resin. The obtained polystyrenesulfonic acid does not undergo disintegration of the molecules and has a narrow MW distribution and good quality.
EMURA TOKUAKI
SHINTANI KOUJI
ODA YASUHIRO
