| 摘要 |
501,806. Coloured artificial filaments, films, etc.; dyeing. ELLIS, G. H., and BROWN, F. Sept. 1, 1937, No. 23924. [Classes 2 (ii) and 15 (ii)] Coloured filaments, straws, foils and the like are prepared by incorporating, in a spinning solution of a cellulose ester or ether a sulphonated dyestuff soluble in the spinning solution but having little or no direct affinity for the cellulose derivative when applied by ordinary dyeing methods, and thereafter spinning the solution into a setting medium. The dyestuff incorporated may be a substantive cotton dye, and it may be of such nature and used in such quantity as to produce a neutral shade on the filaments or the like. These neutral coloured filaments may then be dyed in dark shades with the aid of a colouring material having a direct affinity for the materials. The neutral shade of the filaments can be discharged with discharging agents, so that white or coloured discharge effects may be obtained on the materials after they have been topped with dischargeable direct dyes. The topping colours may be applied uniformly or locally. In an example, extracted and recrystallized Carbide Black D is incorporated in a cellulose acetate spinning solution which is spun into an evaporative atmosphere. The grey yam obtained is scoured in soap solution and dyed by adding 1-amino, 2-methyl anthraquinone. Specifications 282,036, 313,451, [both in Class 15 (ii)], 439,260, and 460,575 are referred to. |
