PURPOSE: To enable ultrafiltration at a substantially high concn. ratio by separating gelatinized cellulose ethers from an aq. medium of which has a temp. above the gel points of the hot water-insoluble cellulose ether by a specified means and treating the remaining aq. soln. by ultrafiltration at a prescribed concn. ratio in a purification step.
CONSTITUTION: In a method for purifying an aq. reaction and/or washing medium contg. hot water-insoluble cellulose ethers and hot water-soluble cellulose ethers and/or macromolecular cellulose ether by-products, in a purification step the aq. medium has a temp. above the gel points of the hot water-insoluble cellulose ethers and gelatinized cellulose ethers are separated from the aq. medium by means of a solid-bowl centrifuge or a disk separator. In a subsequent purification step, the remaining aq. soln. is treated by ultrafiltration at a conc. ratio of at least about 40.
HANSU PEETAA SHIYUNAIDAA
YURUGEN HAAMANSU
URUFU HERUGE HAAGENSEN
