GB1142703A - Improvements in and relating to cellulosic textile materials - Google Patents

Abstract

1,142,703. Treating cellulosic materials. RADUNER & CO. A-G. 29 April, 1966 [10 May, 1965; 21 Jan., 1966], No. 19023/66. Heading DIP. A cellulosic textile fibre is crease-proofed and its abrasion resistance is improved by reacting it with a compound capable of forming intermolecular bands between hydroxy groups in a manner such that the fibre exhibits a higher degree of intermolecular bonding between the cellulosic hydroxy groups towards the centre of the diameter of the fibre throughout its length than is exhibited in the peripheral portions of the fibre. This may be effected by impregnating cellulosic fibres, yarns, or fabric, with a cross-linking agent and a catalyst and before completion of the washfast fixation of the cross linking agent on the cellulosic fibres reducing the effective amount of catalyst in the peripheral portions of the fibres by neutralisation e.g. in the case of acid catalysts by treatment with gaseous ammonia or by applying the neutralising agent in a liquid which may or may not be miscible with the impregnation medium used for the catalyst and crosslinking agent or as a foam, by dissolving the catalyst and/or crosslinking agent off the surface of the fibres, by buffering, by insolubilisation in the case of metal salt catalysts either the cation or anion of the catalyst molecule being rendered inactive by the formation of an insoluble salt, or by increasing the number of hydroxy groups at the surface of the fibres by applying a distillable hydroxy group containing compound to the fibres after or simultaneously with the application of the cross-linking agent and catalyst the compounds accumulating at the surface of the fibres upon drying. Suitable neutralising agents in the case of acid catalysts are ammonia, octadecyl amine, morpholine and soda ash and in the case of alkaline catalysts sulphur dioxide and organic and inorganic acids. The solvent from which the crosslinking agent is applied to the fibres or dissolved therefrom may be a compound having a swelling effect on cellulose even in the absence of water, e.g. dimethyl sulphoxide, dimethyl formamide and dimethylsulphone, so that upon heating the swelling agent becomes concentrated on the surface and crosslinking is effected with the surface of the fibres in the swollen state. The crosslinking agent may be a condensation product of formaldehyde, glyoxal or acrolein with urea, a cyclic alkylene urea, a urein, a triazone or a ketone, formaldehyde, glyoxal, acrolein, acetaldehyde or an aldehyde producing compound, an epoxide, diepoxide or isocyanate, divinyl sulphone or sulphoxide, epichlorohydrin, di-chloro-1, 3-propanol or a sulphonium or phosphonium compound. After impregnation with the crosslinking agent and catalyst and drying fibres may be converted to yarns, yarns to fabrics and fabrics to garments or mechanical treatments, e.g. embossing or compressive shrinking, applied and the material then heated to effect crosslinking, the catalyst deactivation being carried out during or after drying or prior to or during curing. Fibres, yarns or fabrics comprising cotton, linen, jute, hemp, viscose rayon including polynosic fibres, or partially esterified or etherified cellulose fibres alone or in admixture with polyamide, polyurethane, polyester, acrylic or polyolefin fibres may be treated. The treating compositions may also contain a polyethylene softener.