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Some Observations on the Levelling Properties of Acid Dyes I–Level–dyeing Acid Dyes
Author(s) -
LEMIN D. R.,
RATTEE I. D.
Publication year - 1949
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.1478-4408.1949.tb02574.x
Subject(s) - dyeing , levelling , acid dye , chemistry , pulp and paper industry , polymer chemistry , organic chemistry , engineering , geology , geodesy
The rates of dyeing of a large number of level–dyeing acid dyes, measured under specific conditions, tend to decrease with increasing basicity of the dye. The reverse is found to be the case with regard to the relative boiling–off properties of acid dyes. With regard to the production of level dyeings, the Jatter property is of greater importance in view of the general rapidity of uptake of the level–dyeing acid dyes by wool. The effect of pH on the exhaustion of a number of acid dyes has been examined, and the p H–exhaustion curves have been found to follow the shape of the acid titration curves of wool. The sensitivity of the dye exhaustion to p H has been found to increase with the basicity of the dye. A study of the effect of dye remaining in the dyebath after dyeing on the rate of levelling has been made with Naphthalene Red JS and Naphthalene Scarlet 4RS, and a hyperbolic relationship has been found to exist between the time of half–dyeing and the concentration of dye anions in the dyebath. It is shown that good levelling can be promoted only at the expense of exhaustion, and that the safest way in which this can be obtained is by an increase in anion concentration by addition of Glauber's salt or a similar source of anions rather than a decrease in the amount of acid, thereby raising the dyebath p H.