Process for preparing polyamide from diacid-rich component and diamine-rich component

Claim 1

A process for making a high molecular weight, fiber-forming polyamide, said process comprising the following steps: (1) providing a diacid-rich component prepared by melting together at least one dicarboxylic acid with at least one diamine or with a physical or chemical combination of at least one dicarboxylic acid with at least one diamine in a total diacid to total diamine mole ratio, whether free or chemically combined, of about 1.5:1 to 9:1; (2) providing a diamine-rich component selected from the group consisting of at least one diamine and a product obtained by melting together at least one diamine with at least one dicarboxylic acid or with a physical or chemical combination of at least one diamine with at least one dicarboxylic acid in a total diamine to total dicarboxylic acid mole ratio, whether free or chemically combined, of at least 1.5:1; (3) contacting in a melt the diacid-rich component with the diamine-rich component in such proportions that the mole ratio of the total diamine to the total dicarboxylic acid, whether free or chemically combined, is within the range of 0.95 to 1.05 and at sufficiently high temperature to prevent precipitation of solid material; and (4) heating together the molten components with good agitation to a sufficiently high temperature to cause polycondensation, with formation of a liquid high molecular weight polyamide; with a proviso that each of dicarboxylic acid and diamine is a polymethylene compound having 6-12 carbon atoms.