THE STUDY ON THE DYEING OF CELLULOSE ACETATE:(PART VII) THE COLOUR AND THE TEMPERATURE IN DYEING

Abstract

The change of the hue by dyeing concentrations and the relation between the luminosity and the purity were studied through the chromatical diagrams (see diagrams a, b) on dyeing of cellulose acetate.It was shown through the measurement of the colour by means of the automatic colour difference meter that the purity of the colour increases first with the increased concentrations and then it decreases to darker shades after it reached the maximum, the most brilliant point. Most of dyes give the maximum purity at 1_??_2% dyeing concentration and some of them at the deep shade. The relation curves between the luminosity and the purity make a comparison of the brilliancy possible to the dyes with the same colours by criticizing their own positions in the graph.For the most of dyes, the rate of decrease in luminosity falls with increased concentration while the concentration does not reach over a certain range, and the hue tends to change in shade toward the left or right turn in the chromatical diagram as the concentration is increased.