Aq. maleic anhydride and olefin! copolymer salt soln. prepn. - by radical copolymerisation in water-immiscible tri:methyl-cycloalkene or alkenylene ketone and aq. alkali extn.

摘要

Aq. salt solns. of maleic anhydride copolymers with olefins or olefin mixts. are prepd. by radical copolymerisation in water-immiscible trimethyl-cycloalkylene/alkenylene-derived ketones (A) e.g. trimethyl-cyclopentanone, trimethyl-cyclohexanone and isophorone, as solvents. The copolymer soln. is then extd. with aq. alkalies and the aq. alkaline phase is sepd. from the solvent. The aq. alkaline copolymer solns. are used as anionic sizing agents for paper, thickeners and emulsifiers. High copolymer yields are obtd. E.g. in 1:1 maleic anhydride and dicyclopentadiene copolymerisation, copolymer yield is 85 to over 99 wt.% in (A), as opposed to 68-76 wt.% in aromatic hydrocarbon solvents. Over 40 wt.% solns. of non-crosslinked maleic anhydride copolymers can be prepd. in (A).