GB507138A - Finished fibrous materials and process for making same - Google Patents

Abstract

507,138. Degraded celluloses; treating textiles. LILIENFELD, L. Sept. 7, 1937, No. 24416. [Classes 2 (ii) and 15 (ii)] Textile materials are finished by applying to them a solution, colloidal suspension, paste or magma of at least one degradation product of cellulose in a liquid medium capable of dissolving at least a portion of such product, the degradation product being of such a nature that its solutions, dispersions, pastes or magmas in caustic alkali are incapable of yielding coherent films. The materials are thereafter treated with a precipitating or coagulating agent, e.g. an agent capable of coagulating viscose, or water or a solution of alkali carbonate. The degradation product may be prepared by treating cellulose with at least one degrading, hydrolysing or oxidizing agent, for example : (1) with dilute mineral acid in the cold ; (2) with dilute mineral acid at raised temperature; (3) with excess of dilute mineral acid followed by removal of the excess, (1)-(3) with organic acids, e.g. formic acid, acetic acid, glycollic acid, lactic acid, tartaric acid or citric acid, wholly or in part in place of the mineral acid ; (4) with strong sulphuric acid of strength incapable of dissolving cellulose; (5) with strong sulphuric acid capable of dissolving cellulose, followed by precipitation with water; (6) with strong hydrochloric acid; (7) with gaseous hydrochloric acid; (8) with alkali and chlorine; (9) with chlorine or bromine in presence of water; (10) strong organic acid containing chlorine or bromine at raised temperature ; and (11) with hydrochloric acid in presence of potassium chlorate. Other methods of obtaining the degradation product consist in heating the cellulose with or without pressure in absence or presence of water, glycerine, oils, hydrocarbons or the like. Suitable oxidizing agents specified are (1) chloride of lime; (2) hypochlorous acid or a hypochlorite ; (3) solution of chlorine or bromine in water; (4) chlorine in presence of sunlight and water (5) potassium permanganate in presence or absence of alkali; (6) nitric acid; (7) chromic acid; (8) caustic soda solution in presence of air or oxygen; and (9) hydrogen peroxide, alkali peroxide or ozone. The treatment is complete when a solution or dispersion of the product in 7-10 per cent caustic soda solution, spread onto a glass plate and coagulated in an acid or salt bath, does not yield a coherent film. When a far-going degradation is aimed at, the treatment may be regarded as finished when the product is more or less friable. Before being degraded, the cellulose may be -treated with a mercerizing agent. The degradation product'may be applied in conjunction with filling or softening agents or with an alkali-soluble cellulose derivative, e.g. viscose. In an example, wood pulp is treated with hydrochloric acid of 0À5 per cent strength at 100‹ C. for, 6-12 hours. The product is treated with caustic soda of 9 per cent strength, applied to a fabric, and coagulated in a bath used in the viscose art, e.g. a Muller bath. Other examples show the use of other concentrations of degraded cellulose in the caustic soda, solution, other concentrations of caustic soda solution, other concentrations of hydrochloric acid, sulphuric acid of various concentrations, and the addition also of talcum of china clay to the caustic soda solutions. In a further example, the cellulose is treated with caustic soda solution before treatment with acid. In still further examples, the use of chloride of lime and of potassium permanganate in the degradation of the cellulose is illustrated. Specifications 212,864, 231,808, 231,811, [all in Class 2 (ii)], 374,964, 457,031, 459,122, 459,123, 462,456, 462,712, 462,713, 470,746, 474,223, and 490,510 are referred to.