抄録
The viscose films are dyed by some selected dyes, such as Chrysamine G, Direct Brown M, Benzo Cuprol Blue FBL, Benzo Copper Blue 2B and others. The film is treated with the aqueous solutions of the fixing agents, dicyandiamide-formaldehyde resin and Sapamine KW, or cation active levelling agent, Repellate.
The absorption spectra of the films are measured and the deformation of the spectra by these treatments and by exposure to ultraviolet ray is discussed.
The results of these experiments are shown as follows:
(a) By the treatments of the agents the maximum wave length of spectra of dyes are shifted to shorter wave length side, and the fading of the dyed films is accelerated by these agents.
(b) By the modified treatment to which is added copper salt in the bath of the fixing agents, the fading of the films is greatly decreased, but has no relationship to the deformation of the spectra.
(c) The weak new absorption is developed on the dyed films with copper blue dyes at red side of the maximum wavelength of absorption curves. This new absorption is extinguished by fixing treatments, or exposure to ultraviolet ray. The reason of this phenomenon appears that the hydrogen bonding between the dyes and cellulose chain is cut, and the dyes are deposited in the film by fixing treatment or exposure to ultraviolet ray.
