Multicolour diazoprinting with heat volatile

摘要

The heat volatile coupler, applied as usual to the reverse side of the original is a volatile or sublimable addition salt of an azo-coupler contg. an amino group, partic. an aminophenol (meta), aromatic amine and/or amine with an active CH2 (1-phenyl-3-methyl pyrazolone (5)). The acid in the addition salt can be one of a range including HCl and many organic acids. The greater chemical and light stability of the salts prevents unwanted discolourations, and allows a greater number of more accurate copies to be made.