Patent ID: 7776996
Filing Date: 2010-08-17
Classification: C08G,Y02P

Abstract:
1. A continuous process for producing polyamides, their oligomers, or mixtures thereof, and optionally further reaction products, comprising reacting (A) aminonitriles or dinitriles and diamines or mixtures thereof, optionally together with further polyamide-forming monomers and/or oligomers, with (B) an aqueous medium composed of aqueous monomer and oligomer extracts obtained from polyamide production by extraction of the polymer with water, in a reactor which has a vertical longitudinal axis and through which there is a flow substantially in the longitudinal direction, wherein said aqueous medium (i) has a solids content in the range of from 2% to 30% by weight and (ii) is introduced into the reactor at a first location and one or more additional locations along the vertical longitudinal axis, wherein said one or more additional locations are located at least 1 meter higher on said reactor than said first location, from 35% to 95% by weight of the total amount of said aqueous medium is introduced into said reactor at said first location or at one of said one or more additional locations, and the temperature of the aqueous medium introduced at said one or more additional locations is lower than that of the aqueous medium introduced at said first location.