Abstract
The effects of various treatments, such as drawing, dry-heating and steam-heating, on the diffusion of a disperse dye (C. I. Disperse Red 7) in nylon 6 have been studied by means of microspectro-photometric (MSP) method. The diffusion coefficient D was calculated from the diffusion profiles by applying the method of Sekido and Matsui.10)
As expected, the D does not depend on the concentration of the adsorbed dye.
With increasing draw ratio, the D shows a maximum at the draw ratio of 2, and then decreases.
While the D exhibits a minimum at 160°C in dry-heating, it increases with rising temperature in steam-heating.
These behaviours are similar to those of the diffusion coefficient at zero concentration of an acid dye, Naphthalene Fast Orange 2GS.
The partition coefficient changes by these treatment as the similar manner as the D does.
These results are explained by changes of the fine structure of nylon 6 and support Kanetsuna's paper3) which concerns with the concept of qmal.
