GB465606A - The manufacture of dyed artificial masses from regenerated cellulose - Google Patents

Abstract

In a process for the manufacture of dyed artificial masses, particularly films and filaments, of regenerated cellulose, a finely dispersed pigment of a reduced vat dyestuff in a form which is insoluble or difficultly soluble in cold alkali and is fairly stable to oxidation by air, and a dispersing agent are incorporated in the cellulose solution from which the cellulose is then regenerated. Suitable stable reduced vat dyestuff are described in Specifications 334,878, 334,919, 334,920, 338,104, [all in Class 2 (iii)], 350,862, and 359,183. Suitable dispersing or wetting agents are for instance condensation products of higher fatty alcohols or acids with alkylene oxides or substituted carboxylic or sulphonic acids, naphthalene sulphonic acids or their condensation products with formaldehyde, soaps, sulphonated mineral oil, sulphite cellulose waste liquor or mixtures of these substances. The wetting agent and dyestuff are preferably mixed intimately before use, e.g. in a ball or colloid mill. The dyestuff is oxidized during the regeneration, e.g. a spinning process or at most after a short storage. Oxidizing agents, e.g. bichromates may be added to the spinning bath. In an example, 200 parts of finely dispersed Indanthene Brilliant Pink R are reduced in the presence of 1500 parts of water and 1200 parts of ammonium hydroxide (25 per cent) with the aid of 200 parts of sodium hydrosulphite at 92 DEG C. After filtering and washing the reduced dye is made with water into a 13 per cent paste and mixed with 80 parts of a condensation product of oleyl alcohol and ethylene oxide. 23 Per cent of this solution (based on the weight of cellulose) is added to a cuprammonium cellulose solution which is spun in the ordinary way. Other examples describe the use of Indanthene Brilliant Green B and Indocarbon CL plaste. The condensation product of oleic acid chloride with albuminous degradation products of protein material or a sulphonated mineral oil may be employed as the dispersing agent.