GB795869A - Improvements in or relating to methods of copy production or reproduction - Google Patents

Abstract

795,869. Transfer paper. O'SULLIVAN, D. J., and LEFEBURE, E. April 13, 1956 [April 22, 1955], No. 11735/56. Class 96. [Also in Groups XV and XVI] In copy-reproducing processes of the spirit type, the transfer paper is coated with colourless complexes of a dye formed by combination of a dye, reduced dye, or dye intermediate with a non-ionizing salt-free surface-active agent, e.g. a long-chain alkylamiire or an ethylene oxide condensate, and the copy sheet in contact with the transfer sheet is coated or impregnated with an oxidizing agent-which develops the colour of the dye former transferred to the copy sheet by the printing &c, process. Colour formers specified are amino salts of the leuco dye obtained by reacting the leuco dye with a primary amine, e.g. stearyl or lauryl diamine. The salt may be formed in the wax employed as a constituent of the hectograph coating; alternatively an alkali salt of the leuco dye may be used. Suitable oxidizing agents are quinone derivatives, e.g. hydroquinone, or succinic acid derivatives, e.g. N-bromosuccinimide, Two component systems in which one reactant is mixed with the dye intermediate and the other with the liquid used for wetting the copy sheet may be used. In examples: (1) the stearylamine salts of amino leuco crystal violet are reacted with stearylamine at 80‹ C. and the complex formed is mixed with wax and a filler and used to coat a hectograph sheet; (2) the reaction is carried out in presence of the wax. In the above examples, the amine may be replaced by a polyethvlene-oxide condensate. A master is made from the transfer sheets and copy obtained from this master by a hectographic reproducing process is damped with a liquid having one of the following percentage compositions: (A) methylethylketone 99, chloranil 1; (B) methylethylketone 90, tetrachloroethylene 9.5, chloranil 0.5; (C) methylethylketone 80, tetrachlorethylene 9.5; dioxane 10, and chloranil 0.5; (D) methylethylketone 90, perchlorethylene 9.5, N-bromosuccinimide 0.5; (E) acetone 80, dioxane 10, trichlorethylene 9.5 and chloranil 0.5; (F) methylethylketone 90, tetrachlorethylene 9, p-nitrophenyl isocyanate 0.5, and chloranil; (G) methylethylketone 99, chloranil 0.5, p-nitrophenyl isocyanate 0.5.