GB1216883A - New polyamide yarns - Google Patents

Abstract

1,216,883. Filaments for "mixed shrinkage" yarns. E. I. DU PONT DE NEMOURS & CO. 10 Jan., 1968 [10 Jan., 1967; 12 Sept., 1965], No. 1489/68. Heading B5B. [Also in Divisions C3 and D1] A yarn comprises a plurality of continuous oriented polyamide filaments of two types having a difference in filament length of at least 1% when subjected to boiling water under a load of 4 milligrams per denier, the difference increasing by at least 0À5% when the filaments are further subjected to heat setting for two minutes under a similar load, each filament containing at least 50 mole per cent of repeating units of the formula where each of the R radicals which may be the same or different is H or CH 3 , x is 1 or 2, and y is an integer from 7 to 14 inclusive. In examples the diamine used was bis-(4-aminocyclohexyl)- methane, and the acid was one with y = 7, 10, or 14. In the preferred embodiment one type of filaments consist essentially of a polyamide having units of the formula while the other filaments comprise a copolyamide having 50-95 mole per cent of the units of the formula and the remaining percentage of units having a different diamine-for example m- and p-xylylene diamine 1,4-aminomethylcyclohexane and other aliphatic, aromatic or cycloaliphatic diamines- or a different dicarboxylic acid-for example iso- and tere-phthalic acid, 1,4-cyclohexyl dicarboxylic, and aliphatic dicarboxylic acids containing 6-16 carbon atoms. Alternatively all the filaments may be of this copolyamide but with one type of filament having 5 mole per cent more of the units of the formula than the other type; or all the filaments may be composed essentially of the units of the formula with the two types of filaments having (a) different numbers of trans-trans, cis-trans, and cic-cis diamino units in the polymer, (b) different relative viscosities, (c) different chain length in the diacid constituent, or (d) orientation indices differing by at least 1À0 (as by being drawn at different temperatures or by varying the filament denier or conditions at extrusion or quenching). The two types of filaments may differ in a plurality of the above ways. The filaments may contain antistatic agents-e.g. nonylphenoxy capped polyethylene ether alcohol-heat and light stabilizers, antioxidants, ultraviolet light absorbers, delustrants, pigments, dyes, and additives to improve dyeability, soil repellence, crease resistance, hand, water repellence, wickability, strength, elongation, elastic modulus, static propensity, or melting point. The two types of filaments may be spun from the same or different spinnerets and have a round, multilobal or shield shape. They may be intermingled by an air jet. The filaments may be hot-i.e. 140-180‹ C.-or cold drawn, and be heat relaxed after drawing to achieve the desired shrinkage in boiling water. The yarn is bulked, when woven or knitted, by being shrunk in a hot scouring operation while relaxed, or by being cold and/or high tension scoured and then heat set under low tension.