Continuous prodn. of mixed salts of polymers useful as denture adhesives

摘要

Prodn. of a mixed salt of a polymer contg. anhydride, acid and/or ester side gps. comprises: (i) extruding at a predetermined temp. a paste or suspension of a reaction mixt. which has been obtd. by mixing the polymer, a mixed salt cpd. and water at a predetermined ratio; and (ii) drying the resulting polymer mixed salt. Pref. the polymer is a maleic anhydride (or acid)/Me vinyl ether copolymer. Reaction in the extruder is at 40-170 deg C with solids content 20-80% and drying stage (ii) is at 90-120 deg C. The mixed salts are cpds. (esp. (hydr)oxides carbonates or alcoholates) of Na, Ca, Mg, Mn, K, NH4, Zn, Al or Sr and sufficient water is present to hydrolyse the anhydride, acid and/or ester gps. The salt combinations are Ca/Zn, Ca/Mg, Ca/Al, Na/Ca, Mg/Al, Mn/Co, Sr/Zn and Sr/Ca.