GB456552A - Improvements in or relating to the manufacture of artificial filaments, films, sheets and like shaped products - Google Patents

Abstract

Artificial filaments, fibres, films, and like shaped products are obtained from aqueous cellulose solutions to which are added in a form soluble therein synthetic resin components, excluding sulphur derivatives and colloids, and after the filaments or other materials have been formed by extrusion or other shaping process, they are treated to convert the added substances into insoluble or difficultly soluble form by condensation, interaction, polymerization, or like procedure. The cellulose solution may be viscose or a cuprammonium cellulose solution. If desired, the synthetic resin components may be added in a partially condensed or polymerized state. Phenol-formaldehyde, and urea-formaldehyde mixtures or partial reaction compounds are specified. The synthetic resin components may be added at any stage in the preparation of the spinning solution and before the latter is extruded through spinning nozzles. The subsequent process of hardening may be carried out continuously with the production of the filaments, staple fibre, or films, by intercalation with the other treatments to which the material is subjected. In an example, about 1--6 per cent of a soluble polymerization product of phenol and formaldehyde obtained in presence of aqueous ammonia is mixed with an aqueous cellulose spinning solution such as viscose. The filaments or other products obtained are subjected to known hardening treatment such as heating for several hours to 130 DEG C. In another example, an alkaline solution of a pre-condensed urea-formaldehyde mixture is added to cellulose xanthate at the dissolving stage. The viscose is filtered, deaerated, and spun in ripened or unripened condition into a sulphuric acid and sodium sulphate bath. The urea - formaldehyde gradually hardens in the acid solution, and a separate treatment is unnecessary.