GB267207A - Improvements in or relating to the manufacture of compositions containing colouring materials - Google Patents

Abstract

267,207. Whatmough, W. H. Dec. 7, 1925. Carbon papers and ink ribbons.-Pigments or lakes are incorporated with oleaginous materials by precipitating them in the presence of a dilute oleaginous dispersion; the products may be used directly in the manufacture of carbon papers or typewriter ribbons, The oleaginous materials which may be used include fats, oils, and waxes, a small quantity of a stabilizing agent, e.g. an alkali or a soap, being added to the oleaginous dispersion if desired. In examples, (1) a blue pigment is formed by mixing solutions of potassium ferrocyanide and ferric chloride (or of ferricyanide and a ferrous salt), an aqueous castor oil emulsion being previously added to one of the solutions; dispersions of carnauba wax, beeswax, mineral oil, petroleum jelly, or linseed oil may be used instead of the castor oil; (2) methyl violet is dissolved in a carnanba wax dispersion, a finely divided white base consisting of barium sulphate and alumina is added with stirring, followed by solutions of tartar emetic, tin chloride, tannin, and sodium carbonate: a soft purple lake incorporating the wax is obtained; and (3) a blue lake is similarly obtained from Victoria blue. In a modification of the process, the oleaginous material may be incorporated in a white base, e.g. by causing solutions of alum. sodium carbonate, and barium chloride to react in the presence of the oleaginous dispersion: a dye may then be struck on the base. Specifications 4040/09, [Class 2 (iii), Dyes &c.]; and 267,625 are referred to.