GB898889A - Preparation of filamentary structures from synthetic nitrogen-containing polymers - Google Patents

Abstract

Filamentary materials are made by meltspinning synthetic linear fibre-forming polymers such as polyamides, polyureas and polyurethanes having in at least 50% of the recurring units of the main polymer chain a structural unit of the formula:- <FORM:0898889/IV (a)/1> where X is oxygen or sulphur and having from 55 to 160 gram equivalents of amine end groups per 106 grams of polymer, in which there has been dissolved, prior to extrusion, at least 0,05% by weight, based on the weight of the polymer, of one or more of the following phosphorus compounds:- <FORM:0898889/IV (a)/2> and a compound of the formula:- <FORM:0898889/IV (a)/3> where R is an alkyl, cycloalkyl, alkenyl, aryl, aralkyl or aralkenyl group, n is a whole number equal to the valency of the metal, Z is hydrogen or an alkyl, cycloalkyl, alkenyl, aryl, aralkyl or aralkenyl group, or an alkyl substituted ammonium group, or R and Z together are an alkylene group when joined to form a ring structure. Preferably the polymer is a polyamide having in at least 90% of the recurring units of the main polymer chain a structural unit of the formula:- <FORM:0898889/IV (a)/4> or <FORM:0898889/IV (a)/5> wherein X is oxygen or sulphur, A is a divalent organic radical and each B is a monovalent organic radical or hydrogen, and contains from 60 to 120 gram equivalents of amine end groups per 106 grams of polymer and at least 0,2%, based on the weight of the polymer, of the phosphorus compound(s). Preferred phosphorus compounds are sodium phenyl phosphinate and sodium 2,5-dimethylphenyl phosphinate. A long list of other suitable phosphorus compounds is given. The desired concentration of amine end groups in the polymer may be obtained by adding an appropriate amount of a primary or secondary amine or polyamine, e.g. methylamine, ethylamine, n-propylamine, isopropylamine, hexamethylene diamine, piperazine, N-aminopentylpiperazine, N,N1-diaminopentyl-piperazine and N-aminopropyl-morpholine or, in the case of a polyamide derived from a diamine and a diacid, by using a slight excess of the diamine reactant. The polymer may also contain at least 0,2% by weight, preferably 1-5%, of a finely divided delusterant, e.g. titanium dioxide, barium sulphate or aluminium oxide, and the light-stability of the extruded polymer may be improved by the addition of manganous hypophosphite (e.g. 0,02%). After spinning, the phosphorus compound may be removed from the yarn by scouring with a suitable solvent, e.g. water containing soap or detergent. Yarns obtained by the process of the invention are deeply and uniformly dyeable at a higher rate than conventional yarns, and spinning may be carried out for long periods without interruptions due to the formation of drips on the spinneret. U.S.A. Specification 2,648,695 is referred to.