Patent GB-1340034-A (GB)
Title: Regenerated cellulose
IPC: D06M15/423
Filed: 1969-12-24
Abstract: 1340034 Treating regenerated cellulose ENGLISH CALICO Ltd 11 Jan 1971 [24 Dec 1969] 62966/69 Heading D1P A process for improving the dry and wet crease resistance of regenerated cellulose material comprises treating the material with a reactive substance (as hereinafter defined) capable of reacting with the cellulosic hydroxyl groups, and catalyst for the reaction between the reactive substance and the cellulosic hydroxyl groups, in homogeneous mixture with an organic liquider liquids and allowing the reaction to take place in the presence of more than 10% but not more than 25% of water calculated on the dry weight of the textile material. The water present during the reaction may be water present in the textile material before treatment, or it may be added during treatment or it may be the combined water present before treatment and added during treatment. Preferably the water present during the reaction is 12 to 25% and especially 12 to 18% inclusive. The process may be carried out in as a one to two step process. In the one step process the reactive substance together with the catalyst and organic liquid or liquids may be applied to the material in solution or emulsion form. The application may be carried out by a lock roller or by conventional impregnation and removal of surplus liquor by squeezing or vacuum extraction. In the two step process the reactive substance may be applied to the material from aqueous solution or alternatively from solvent solution or emulsion. After drying, the material is then subjected to treatment with the catalyst or suspension in the organic liquid or liquids, but it is possible to apply the reactive substance together with the catalyst from aqueous solution and to bring about the reaction by treatment of this material with the organic medium. After the treatment with the substance and catalyst the material may be stored in order to allow the reaction to occur. The process may be carried out between 10‹C and the BPt. of the organic liquid or liquids. Preferably the process is carried out at 15 to 25‹C for 5 to 24 hours or at 50 to 70‹C for 5 to 10 minutes. By the expression "reactive substance" is meant formaldehyde and its polymers, acetals. Thermosetting resins such as urea-formaldehyde and melamine-formalde,- hyde, methylol derivatives of amides such as ethylene urea, propylene urea and di-hydroxyethylene urea, triazones and carbamates, all of which are capable of reacting with cellulosic hydroxyl groups in the presence of acid catalysts and also, vinyl sulphones or their percusors, vinyl sulphonium compounds or their precursors, dichloro compounds e.g. dichloro triazines and dichloropropanol, diepoxy compounds and acrylamide all of which are capable of reacting with cellulosic hydroxyl groups in the presence of alkaline catalysts. Suitable organic liquids are those which are inert to the catalyst chosen and capable of forming a homogeneous mixture, either solution or dispersion, with the catalyst and/or the reactive substance. Suitable liquids are primary and secondary alcohols, ketones, esters, hydrocarbons, chlorinated hydrocarbons and polyglycols. Preferably the catalyst is a strong acid such as hydrochloric acid.