Continuous prepn. of homogeneous polymer soln. - by kneading polymer suspension in solvent in screw extruder, for filaments and tapes

摘要

In continuous prepn. of homogeneous solns. of high mol. polymers, a finely divided polymer is suspended in a solvent, and the suspension is mixed and kneaded at a mechanical shear rate of 5-2000/sec., in a screw extruder, at 30-300 revs./min.; the extruder has transport sections and e kneading sections. Treatment is for 0.5-45 mins., at above 90 deg. C and below the b.pt. of the solvent at the pressure in the extruder. A twin-screw, co-rotating extruder is used. The suspension is mixed and kneaded for not more than 10 (pref. not more than 5) mins. The suspension contains at least 50 wt.% solvent.