Abstract: The invention provides a dye composition for dyeing fibers comprising (a) an azo dye of formula (II) or a salt thereof, and (b) an azo dye of formula (III) or a salt thereof. The invention provides navy and black dye compositions, especially suitable for dyeing secondary cellulose acetate fibers, with superior fastness properties than known navy/black dyes. Preferably, the &agr;-crystal form of dye (III) is used, which has greater solubility and achieves quicker dyeing than the commonly-used &bgr; and &ggr; forms of (III) when dyeing cellulose acetate at 60-95° C. A new method of making the &agr; form is disclosed.
September 22, 2000
Date of Patent:
April 2, 2002
Yorkshire Chemicals PLC
Christopher Whitham, Alan John Buckley, Rebecca Jane Crowson
Abstract: A composition suitable for use in a process for electroplating surfaces with tin, including an alkane sulphonic acid optionally together with an aryl sulphonic acid; a tin source; and an additive, such as a reaction product of a sulphonating agent with Bisphenol A.