直接染料によるビニロンの染色
(II) 無塩の場合の染色
1959 年 15 巻 12 号 p. 1011-1014,1007
詳細
1959 年 15 巻 12 号 p. 1011-1014,1007
The absorption isotherms of C. I. Direct Red 1 and C. I. Direct Red 2 on Vinylon in absence of salt were decided at 90°C.
According to the direct dyeing theory, a direct plot of the concentration of dye in the dye-bath against the concentration of dye on the fibre yields a straight line passing thuough the origin.
The results obtained does not agree with the prediction of the dyeing theory, but the concentration of dye on the fibre is represented approximately by a following equation,
From this behavior, and the fact that the heat of dyeing on Vinylon is dependent of the concentration of absorbed dye, it is assumed that Vinylon contains a limitted small number of sites for which the dye has a high affinity and a large number of less active sites. The affinity of the dye on Vinylon corresponding to less active sites was calculated from the straight line part of the isotherm, and compared with the affinity obtained in presence of salt. The affinity corresponding to less active sites is considerably smaller than that obtained in the presence of salt.
To explain this behavior, it is asummed that decrease of the degree of hydration of the dyemolecule by adding NaCl raises the affinity of the dye on Vinylon as described in the preceeding paper.
