繊維素の直接染色に関する研究

第11報　染着性と共役二重結合鎖(IV)

抄録

As part of a study on the factors determining the absorption properties of direct dyes on cellulosic materials, the relation between the dyeing properties and the conjugated system of double bond are considered under the same condition, described in part IX. (K. Nishida; Sen-i Gakkaishi, 16, 575 (1960)). The dyes used are Nippon Dark Green B conc. (C. I. Direct Green 1. C, I. No.30280) (I) and the triazole derivative of Nippon Dark Green B conc. (II). The triazole derivative was prepered from (I) as follow. (I) (1/100mol) in water (300cc) was treated by a good stirring at 90°C. for 1-2hr. with 25% ammonia (10cc) and crystalline copper sulphate (5g) in water (about 20cc). The copper is removed by means of the salt solution acidified with sulphuric acid and the product purified by repeated precipitation with sodium acetate (Ciba, U. S. P. 2788, 3457 (1957)). The absorption band of the dye (I) at about 600 mμ almost disappeares. The amounts of (I) and (II) in equilibrium at the various temperatures were measured. Dyeing was carried in a stoppered hard-glass flasks which was agitated mechanically under the same condition as in previous report (K. Nishida; J. Soc. Dyers Colourists, 76, 551 (1961)). From these results the standard affinity (-Δμ°), the heat of dyeing (-ΔH°) and the standard change in entropy (-ΔS°) of (I) and (II) were determined. The experimental data obtained with (I) and (II) are represented by three quantities, namely -Δμ° (cal/mol)=7200 (I) and 5200 (II), -ΔH° (cal/mol)=6600 (I) and 1700 (II), -ΔS° (cal/deg.mole)=-1.7 (I) and -9.9 (II), respectively. Such difference of dyeing properties may be explained on the following grounds. The dye (II) does not contain any longer conjugated chain than (I), owing to the introduction of insulating groups into the conjugated chain. Therefore, the dye (II) is more bulky.