Process for producing polyamides with lactam or urea solvent and CaCl.sub.2

A process for producing a fiber, film, fibroid or other shaped article forming aromatic polyamide having a logarithmic viscosity (.eta.inh/of) from about 4.3 to 8.8, comprising subjecting (A) a mixture of at least one aromatic diamine of the formula (1):

• H.sub.2 N--Ar.sub.1 --NH.sub.2 ( 1)
• and at least one aromatic dicarboxylic acid dihalide of the formula (2):
• XOC--Ar.sub.2 --COX (2),
• (b) a mixture of at least one of the aromatic diamines of the formula (1), at least one of the aromatic dicarboxylic acid dihalides of the formula (2) and at least one hydrogen halide salt of aromatic amino carboxylic acid halide of the formula (3):
• XH.H.sub.2 N--Ar.sub.3 --COX (3)
• or (C) at least one of the hydrogen halide salts of the aromatic amino carboxylic acid halides of the formula (3), wherein Ar.sub.1, Ar.sub.2 and Ar.sub.3 respectively represent, independently from each other, a divalent aromatic or heteroaromatic radical having two essentially coaxial or parallel, oppositely directed, chain extending bonds or a divalent heteroaromatic radical having two bonds extending from said radical with a maximum spacing from each other and X represents a halogen atom, to a condensation polymerization in a medium of at least one solvent selected from the group consisting of N-methyl-2-pyrrolidone containing calcium chloride in an amount of 1.5% or more but less than 5% based on the weight of the N-methyl-2-pyrrolidone, and dimethylacetamide, N-methylcaprolactam and tetramethylurea respectively containing calcium chloride in an amount of 1.5% to 8% based on the weight of the respective solvent compound, kneading said polymerization mixture, after the viscosity of said polymerization mixture reaches between 500 and 10,000 poises as determined by a falling-ball viscometer, until the logarithmic viscosity of the resultant polymer reaches from about 4.3 to 8.8, said logarithmic viscosity being determined by using a 5 g/dl solution of said polymer in 98.5% sulfuric acid at 30.degree. C., and isolating the resultant polymer from the polymerization mixture.