Process for the discontinuous production of aromatic in mixture of polyamides calcium chloride and N-methylpyrrolidone-2

Claim 1

A process for the discontinuous production of a spinnable polyamide consisting of repeating units of the generic formula: ##STR12## in which 50 to 100% of the radicals R are p-phenylene radicals and the remaining 0 to 50% of the radicals R consist essentially of n-butylene radicals, which polyamide has a fiber-forming viscosity, measured at 25° C. on a solution in 100% strength sulphuric acid which has a concentration of 0.5 g of polymer in 100 ml of solvent, characterized in that terephthaloyl chloride, or terephthaloyl chloride and adipoyl chloride, is reacted with a solution selected from the group consisting of para-phenylenediamine, 4,4'-diaminoadipanilide, and a mixture of the same, in a mixture of N-methylpyrrodlidone-2 and calcium chloride, under conditions such that: the acid chloride or chlorides and the diamine or diamines are in essentially stoichiometric proportions; the solution of diamine or diamines in the mixture of N-methylpyrrolidone-2 and CaCl 2 is homogeneous and substantially anhydrous; with the CaCl 2 initially being in and remaining in solution at the time of its use; the calcium chloride content is such that the ratio C m of the number of mols of calcium chloride to the number of units: ##STR13## is between 0.70 and 2.90; and the relative amounts of reactants and solvents are chosen such that, at the end of the reaction, the polymer content of the resulting polymer-containing composition obtained is between 5 and 16% by weight, relative to the N-methylpyrrolidone-2.