Ciba-Geigy Corporation

Peter Franceschini

Raymond Defago

Walter Mosimann

Rolf Bauerle

Hanspeter Hermann

A process for computing a dyeing or printing recipe corresponding to a given shade, wherein a) a given shade in a FTa*b* colour space is defined, where FT is a depth of shade value which, irrespective of hue, defines points of equal colour strength which by definition lie in a plane of the FTa*b* colour space as defined, and a* and b* are values of the CIELab colour coordinate system, b) the FTa*b* colour space for each depth of shade plane is segmented into triangular levels by means of the a* and b* values of the dyes to be used for colour matching, c) in each defined depth of shade plane the given a* and b* values correspond to a specific ratio of the dyes of the suitable segment of the colour space, and d) the ratio of the dyes of the suitable segment is obtained by an iteration method. The process makes it possible to formulate dyeing and printing recipes accurately in accordance with a given reference shade.

Process for computing dyeing and printing recipes in accordance with a

A wet transfer process for dyeing and printing synthetic and natural nitrogenous material by applying to an inert support a printing ink which contains at least one dye and/or fluorescent brightening agent, a binder or thickener, water and/or an organic solvent, and drying said ink, then bringing the treated side of the support into contact with the surface of the material to be dyed which has been pretreated with an aqueous solution or emulsion, subsequently subjecting support and material, with or without mechanical pressure, to a heat treatment of 100.degree. to 130.degree. C., preferably 105.degree. to 120.degree. C., for 1 to 100 seconds, preferably 20 to 60 seconds, and then separating the dyed or printed material from the support, which process comprises the use of a hydrophobic inert support which contains at least one non-sublimable dye having fibre affinity, and pretreating the synthetic and natural nitrogenous fibrous material with an aqueous, thickened solution or emulsion which contains a coacervating agent and an acid or an acid donor.

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Movelier, Switzerland

Peter Franceschini