GB391963A - Improvements in or relating to the production of photographic pictures - Google Patents

Abstract

391,963. Photographic diazotype processes. KALLE & CO. AKT.-GES., 23, Rheinstrasse, Biebrich-on-Rhine, Germany. March 29, 1932, No. 9070. Convention date, March 28, 1931. [Class 98 (ii).] A light-sensitive layer for copying photographic pictures comprises one or more diazo compounds of aromatic diamines, and one or more aromatic amino or hydroxy compounds which yield dyestuffs when treated with oxidizing agents. In a modification, any diazo component which is decomposed by light is used as a source of the aromatic amino or hydroxy compound. In examples : (1) a solution containing phenol and the cadmium chloride double salt of p-phenylenediamine, one amino group of which is diazotized, is applied to paper and exposed under a negative ; a blue-black positive is obtained by oxidizing with acidified potassium permanganate ; (2) aniline hydrochloride is used in place of the phenol; (3) a bluish-red positive is obtained by using diazotized 1-amino-7- hydroxynaphthalene in place of phenol ; (4) a solution containing p-phenylenediamine, one amino group of which is diazotized, and the cadmium chloride double salt of 4-diethylamino 2-hydroxy-1-diazobenze is applied to paper and after exposure is oxidized with aqueous copper-oxide-ammonia ; naphthalenetrisulphonic acid may be added to the sensitizing solution ; (5) in the process of example 4, iron chloride solution or hydrogen peroxide is used for the oxidation ; (6) the calcium chloride double salt of 4-diethylamino-2-hydroxydiazobenzene and p-diazodiphenylaminesulphate or its derivatives are used as the sensitizing agent ; (7) the cadmium chloride double salt of diazodimethylaniline and the cadmium chloride double salt of 4-diethylamino-2-hydroxydiazobenzene are used as the sensitizing agent ; (8) the zinc chloride double salt of 4-diethylamino-2-hydroxydiazobenzene and the cadmium chloride double salt of 4 : 4<1>-tetrazodiphenylamine or the cadmium chloride double salt of 4 - dimethylamino - 3 - methyldiazobenzene are used as the sensitizing agent ; (9) the sodium salt of 2-diazo-1-hydroxynaphthalene-4-sulphonic acid and the cadmium chloride double salt of p-phenylenediamine, one amino group of which is diazotized are used as the sensitizing agent. The alkyl, oxyalkyl, alkyloxy, and halogen derivatives of aromatic hydroxy and amino compounds are referred to, and glass plates and films of cellulose or cellulose derivatives may be used as supports. The sensitizing agents may also be present in the mass of the support which may be of regenerated cellulose or cellulose esters or ethers. Metal salts,. stabilizers, dyestuffs, and other assistants which are used in diazotype processes may be present.