| 摘要 |
Positive diazo image is obtained by dry development by radiating material with energy of wave length different from UV-radiation. Shift of pH value into alkaline region is effected by reduction of suitable cpd in diazo material, initiated by photo desorption of semiconductor pigment. Suitable pigments include CdS and ZnO. Salts of aliphatic acids or hydroxides may be used for reduction of zinc. Suitable dyes include acridine-, xanthene-, diphenylmethane-, quinoline- and azo dyes. All known sensitive diazo cpds may be used. After UV-radiation which causes decomposition of diazo cpd in exposed regions, material is radiated with visible light, leading to photo desorption of pigment, causing pH shift; positive reproduction of original is obtained. Spectral region in which development can take place is influenced by dye sensitation of pigment. |
