| abstract |
The continuous prodn. of high-mol. wt., esp. amorphous, partly aromatic copolyamides (I) based on hexamethylenediamine (HMDA), opt. other diamines, isophthalic acid (IPA), terephthalic acid (TPA) and other starting materials (II), comprises heating an aq. reaction mixt. contg. aq. diamine soln. and the other reactants under at least 15 bar pressure to give a precondensate, then raising the temp. and pressure to give a prepolymer and then completing the polycondensation in a degassing extruder to give the copolyamide (I); total reaction time is not above 2.5 hrs. Also claimed are copolyamides (I) obtd. by this process. USE/ADVANTAGE - The invention provides an economical process for the continuous prodn. of amorphous, high-viscosity aromatic copolyamides (I), with total reaction time not above 150 mins. (cf. 3-7 hrs. for the batch process); the prods. (I) have the high-mol. wt. and viscosity required for high-grade packaging applications or for use in the car industry. |