GB112474A - Improvements in or relating to Dye Stuffs and Dyes. - Google Patents

Abstract

112,474. Malcolmson, N. Oct. 10, 1916. Dyes from natural products.-A dye paste or pulp is obtained by injecting steam into a mass of raw seaweed while retaining the juices in the mass; the paste or pulp may be concentrated by evaporation. A dye extract may be obtained by boiling olive, brown, or red seaweed in an acid solution, and green or khaki extracts may be obtained by treating the residue after the acid extraction with hot alkali; or the weed may be extracted first with hot alkali and then with boiling acid. The acid solution may be evaporated down until caramelization occurs, products of different shades being obtained thereby. Specifications 4166/73, [Class 70, India-rubber &c.], 56/79, 1215/81, and 15233/00 are referred to. According tn the Provisional Specificacation, dyes are obtained by steeping seaweed in water; the weed may be previously chopped up and stacked and allowed to decompose; pastes or extracts may be obtained by means of pressure or steam; the solutions may be concentrated by evaporation or wood flour or other absorbent may be impregnated with the solution; or wood flour may be ground up with the disintegrated seaweed. A variety of shades may be obtained by extracting with hot water the residues resulting from the acid and alkali treatments described above. The various dyes may be used with mordants, or topping baths, or with other dyes; the use as mordants of potash and alum, ferrotannic compounds, ammonium stannochloride, tannin, or used tea leaves as a substitute for tannin, is specified; the dyes may be precipitated by salt, and combine with alumina etc.; salt or sodium sulphate may be added to the dye baths.