GB656364A - Diazotype photo-printing layers containing resorcinol derivatives - Google Patents

Abstract

656,364. Photographic diazotype material. GENERAL ANILINE & FILM CORPORATION. Jan. 7, 1949, No. 522. Convention date, Jan. 20, 1948. [Class 98 (ii)] An azo coupling component for incorporation in photographic diazotype material or in an alkaline developing solution therefor is a carbonic ester of resorcinol, which may be obtained by reacting resorcinol with phosgene in the presence of a base such as pyridine, dimethylaniline, or quinoline. The resorcinol carbonate may be di-resorcyl carbonate or a polymeric resorcinol carbonate. Two-component material containing a resorcinol carbonate as coupling component is stable to precoupling. The coupling component may be incorporated in the sensitizing composition or applied separately either in a separate solution or by rubbing it in powdered form on the surface of the support, which may be paper, transparentized paper, regenerated cellulose, or a cellulose ether or ester. Numerous diazo compounds are specified. In example 1, transparentized paper is coated with an aqueous solution of a resorcinol carbonate (prepared by reaction of 1 mol. of resorcinol with 1 mol. of phosgene), N - (21 - hydroxyethyl) : N - methylaniline - p - diazonium chloride zinc chloride double salt, isopropanol, ethylene glycol, citric acid, thiourea, and saponin. The exposed material is developed with ammonia vapour. In example 2, the procedure is similar using a resorcinol carbonate prepared by reaction of 2 mols. of resorcinol with 1 mol. of phosgene. In example 3, transparentized paper is sensitized with an aqueous solution of N-ethylaniline - p - diazonium chloride - zinc chloride double salt or N : N-diethylaniline-p-diazonium chloride-zinc chloride double salt, a resorcinol carbonate as in example 1, citric acid, phosphoric acid, isopropanol, and thiourea. In example 4, the procedure is similar to example 2, using the zinc chloride double salt of N-ethylo-toluidine-p-diazonium chloride. Ammonia development may be replaced by wet or semiwet development with a solution of an alkali metal carbonate or tertiary phosphate, and one-component material may be developed with a similar solution containing the coupler.