A Process for Dyeing Wool or other Animal Fibres and Fibre Mixtures containing Wool with Aniline Black.

摘要

26,962. Bethmann, G. Dec. 27. Dyeing.-In dyeing wool and other animal fibre and mixed goods containing wool and cotton with aniline-black, the wool &c. is first well cleaned, then neutralized with dilute acid or acid vapours, and then padded with a usual padding mixturecontainiug ouly sufficient chlorate for the oxidation of the aniline, in contradistinction to a similar process described in Speci6cation No. 21,236, A.D. 1900. The colour is subsequently developed, a fast, unitorm black with a bluish shade being obtained, even in mixed goods. The goods are well cleaned with soap, ammonia, or other suitable alkali, and then rinsed in water and either further treated moist or dried. In the latter case, they must be steeped in hot water before the next treatment. The water may be slightly acidified or contain a little acid salt, such as magnesium chloride. The alkalinity of the wool is then neutralized by treatment for about an hour with an aqueous solution of sulphuric or other acid. Boiling facilitates the process, but is not necessary. After being rinsed and wrung out, the goods are impregnated with an aniline-black padding mixture, such as is used in cotton dyeing, and the colour is then developed as usual by moist oxidation or steaming. The goods are finally treated with alkali bichromate, mixed, and washed in water or only washed in water or treated in alkaline solutions, or both methods may be combined. The cleaned wool may be treated with acid vapours; instead of with the aqueous solution described. The wool is spread out on hurdles in hydrochloric acid vapour, for instance, or carried mechanically through rooms filled with the vapour. Specification No. 2327, A.D. 1865, is referred to.