GB619576A - Manufacture of new polyamides - Google Patents

Abstract

Equimolecular proportions of 1 : 6-diamino-6-methyl-heptane and an aliphatic dicarboxylic acid are heated together to give a polyamide. Amide forming derivatives or low molecular weight polymers or the preformed salt may be used. The reactants are heated until filaments formed from a melt of the polyamide can be cold-drawn into fibres. The acids include oxalic; glutaric; adipic; pimelic; suberic; azelaic; sebacic; brassylic; tetradecanedioic; octadecanedioic; p-phenylenediacetic; hexahydroterephthalic and 1 : 3-cyclopentane dicarboxylic acids. The heating, which is usually at from 200 DEG to 300 DEG C. in the presence or absence of solvent or catalyst and preferably in the absence of air or oxygen, is performed under conditions allowing the removal of water, e.g. under reduced pressure, at least during later stages. A mono-functional amide-forming reactant may be used to stop the reaction at any stage as described in Specification 495,790. The products are soluble in methanol and ethanol and may be made into films forming strongly adhesive bonds to glass, metals and similar surfaces. Solutions in water-miscible organic solvents on mixing with water provide stable aqueous dispersions. In an example, a solution of 1 : 6-diamino-6-methylheptane in ethanol is added to an ethanol solution of adipic acid, the white crystalline salt separating out on standing. The salt is heated for 3 hours at 220 DEG C. in a closed vessel, which after cooling is opened and heated at 255 DEG C. for 1 hour at atmospheric pressure and then for 12 hours at 0.3 mms. pressure. The product, which has an intrinsic viscosity of 0.74, softens at 100 DEG C. and can be spun at 165 DEG C. to filaments which may be cold-drawn.ALSO:1 : 6-Di-amino-6-methyl heptane is converted into an aliphatic dicarboxylic acid salt by interacting equimolecular proportions of the amine and adipic acid in ethanolic solutions, the salt crystallizing out on standing. Reference is made to the formation of salts of the amine with other aliphatic dicarboxylic acids, e.g. oxalic, glutaric, pimelic, suberic, azelaic, sebacic, brassylic, tetradecanedioic, octadecanedioic, p-phenylene diacetic, hexahydro-terephthalic and 1 : 3-cyclo-pentane dicarboxylic acids. The salts are starting materials for the production of polymeric amides (see Group IV (a).