Patent GB-723076-A (GB)
Title: Improvements in or relating to the sizing of yarns
IPC: D06M15/263
Filed: 1952-11-25
Abstract: Water-insoluble nylon yarns are sized prior to weaving with an aqueous solution having a pH between 2 and 5 containing from 2 to 15 per cent by weight of a water-soluble copolymer of substantially equimolecular proportions of maleic acid, maleic anhydride or an alkyl half-ester of maleic acid in which the alkyl group contains from 1 to 4 carbon atoms, or a mixture thereof, and vinyl acetate, the amount of copolymer deposited on the yarns being from 0.5 to 5 per cent by weight of the dry yarns; the yarns are then dried.  The nylon yarns may be produced from the condensation product of hexamethylene diamine with adipic or sebacic acid.  An aqueous size with a pH of 2 to 3 is obtained from a copolymer of equimolecular proportions of vinyl acetate and maleic acid or anhydride or a mixture of maleic acid and the anhydride, or a mixture of maleic acid, maleic anhydride and a minor proportion of methyl acid maleate, and solutions having a pH of 3 to 5 may be obtained by adding alkali to such solutions. An aqueous size having a pH of 3 to 5 is also obtained by dissolving copolymers of equimolecular proportions of vinyl acetate, methyl acid maleate or secondary butyl half acid maleate or mixtures of such half esters with maleic acid and/or its anhydride, in water with an amount of alkali considerably less than the stoichiometric proportion required to neutralize the copolymer. The size may also contain glycerine, ethylene glycol, sorbitol, propylene glycol, a polyethylene glycol, a polyglycerol, or a polypropylene oxide; a sulphonated animal, vegetable or mineral oil, a water-emulsifiable mixture of such oils with animal oils, mineral oils, vegetable oils and Twitchell oil; an alkyl-substituted benzene sodium sulphonate or an alkali metal or ammonium monoalkyl sulphosuccinate in which the alkyl group contains from 10 to 20 carbon atoms; or a surface-active condensation product of ethylene oxide with an alkylated phenol or an alkyl mercaptan in which the alkyl group contains from 8 to 20 carbon atoms.  The size may be applied at between 100 DEG  and 200 DEG  F. by impregnation or spraying, excess solution being removed by squeeze rolls.  The treated yarn may be air-dried at 65 DEG  to 85 DEG  F. or passed through an oven in which air at 140 DEG  to 250 DEG  F. is circulated, or the yarns may be passed over drying cylinders heated to 140 DEG  to 250 DEG  F. until they are dry or contain less than 10 per cent moisture.  Specifications 461,236 and 461,237 and U.S.A. Specifications 2,071,250, 2,130,532 and 2,130,948 are referred to.ALSO:A sizing composition for nylon comprises an aqueous solution having a pH between 3 and 5 containing 2 to 15 per cent of a water-soluble copolymer of substantially equimolecular proportions of maleic acid, maleic anhydride or an alkyl half-ester of maleic acid in which the alkyl group contains from 1 to 4 carbon atoms, or a mixture thereof, and vinyl acetate.  An aqueous solution with a pH of 2 to 3 is obtained from a copolymer of equimolecular proportions of vinyl acetate and maleic acid or anhydride or a mixture of maleic acid and the anhydride, or a mixture of maleic acid, its anhydride and a minor proportion of methyl acid maleate.  Such solutions may be brought to a pH of 3 to 5 by the addition of sodium hydroxide, or aqueous solutions at this pH range may be obtained by dissolving copolymers of equimolecular proportions of vinyl acetate and methyl acid maleate, secondary butyl acid maleate or mixtures of such half esters with maleic acid and/or its anhydride, with an amount of alkali considerably less than the stoichiometrical proportion required to neutralize the copolymer.  The solution may also comprise glycerine, ethylene glycol, sorbitol, propylene glycol, a polyethylene glycol, polyglycerol or polypropylene oxide; a sulphonated animal, vegetable or mineral oil or a water-emulsifiable mixture of such oils with animal, vegetable or mineral oils and Twitchell oil; an alkyl-substituted benzene sodium sulphonate or alkali metal or ammonium mono-alkyl sulphosuccinate in which the alkyl group contains from 10 to 20 carbon atoms; or a surface - active condensation product of ethylene oxide with an alkylated phenol or an alkyl mercaptan in which the alkyl group contains from 8 to 20 carbon atoms. Specifications 461,236 and 461,237 and U.S.A. Specifications 2,071,250, 2,130,532 and 2,130,948 are referred to.