Continuous manufacture of an aqueous solution of a salt of an alkanedicarboxylic acid and an alkanediamine

A continuous process for preparing an aqueous solution of a salt of an alkanedicarboxylic acid having 6 to 12 carbon atoms and an alkanediamine having 6 to 12 carbon atoms which comprises reacting the particular alkanedicarboxylic acid with the particular alkanediamine in an aqueous solution of the salt to be prepared by (1) recycling an aqueous solution of said salt from a first mixing zone through a transport zone and then a second mixing zone back to said first mixing zone, the amount of salt solution circulated per hour being from 40 to 80 times the amount contained in said first mixing zone, (2) introducing an aqueous solution of said alkanedicarboxylic acid and less than the equivalent amount of said alkanediamine in liquid form into said recycling salt solution at a location between said first and second mixing zones, (3) introducing an additional amount of said alkanediamine in liquid form into said recycling salt solution at a location after said second mixing zone, the amount of alkanedicarboxylic acid and the total amount of alkanediamine introduced being approximately equivalent, (4) maintaining the aqueous solution at a temperature in the range of 90.degree. C. to 102.degree. C., and (5) removing aqueous salt solution from the first mixing zone at a rate corresponding to the rate at which it is formed.