New Developments in the Application of Phthalocyanines in Textile Printing

Abstract

A completely new method of using phthalocyanines in textile printing was introduced by the discovery of the Phthalogens, from which the phthalocyanine pigment may be produced in the fibre. Special methods of application were developed, which are characterised by the use of 10–20% of special solvent mixtures, the Levasols, in the aqueous printing pastes containing the intermediate product and the metal, the latter in the form of a soluble salt or as a complex compound. The printing method is adapted to the usual processes and apparatus used in textile printing. Particular attention must be paid to the drying of the prints and pads. Condensation to the dye is best carried out by steaming. The printing process with Phthalogen Brilliant Blue IF3G, the intermediate product, which with a popper salt or the copper complex compound Phthalogen K gives very bright blues of high fastness to light, weather, and boiling, and with nickel salts greenish blues of equally high fastness properties, is described in detail, and the solubility and the stability of the intermediate product are discussed. The possibility of printing alongside dyes of other groups is considered. Success has recently been achieved in developing a process for the production of white and coloured resists under Phthalogen Brilliant Blue IF3G, the resisting agent being an organic base (Phthalotrop B). The production of a green phthalocyanine pigment on the fibre has been made possible by the manufacture of the intermediate product Phthalogen Brilliant Green IFFB. The printing process is similar to that used for the production of the blue dye. The lower solubility of the intermediate product requires the use of another solvent, Levasol F, and the dispersing agent, Emulsifier W. Owing to its extraordinary brightness and outstanding fastness properties, the dye containing copper is of greater importance, the copper being applied as Phthalogen K. The method of printing is discussed, as well as the possibility of application alongside other dye groups in direct printing.