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Colour Differences in Azo Pigments I—The Effect of Precipitation Conditions
Author(s) -
Hildreth J. D.,
Patterson D.
Publication year - 1963
Publication title -
journal of the society of dyers and colourists
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 0037-9859
DOI - 10.1111/j.1478-4408.1963.tb02515.x
Subject(s) - pigment , hue , chemistry , precipitation , organic chemistry , optics , physics , meteorology
The variability in colouring properties, both hue and strength, between batches of the same dye or pigment is a constant source of difficulty to colorant manufacturers, but there is very little published information on the subject. Three azo pigments (Toluidine Red, Hansa Yellow G, and Parachlor Red) were selected for an investigation of the effects of changes in the coupling conditions used in their preparation on the hue of the resulting pigments. The colour differences were measured instrumentally in NBS units. The effect of a given change in conditions differed from pigment to pigment. The differences in colouring properties found between samples of the same pigment made under various conditions are ascribed to physical and not chemical causes.