GB513029A - Improvements in or relating to reflex-copying processes - Google Patents

Abstract

513,029. Reflex copying processes. KALLE & CO. AKT.-GES. Nov. 26, 1937, No. 32744. Void. Convention date, Nov. 26, 1936. [Class 98 (ii)] In a reflex copying process using diazotype sensitive material, a layer is arranged between the light source and the sensitive layer and is sensitized with a diazo compound the permeability of which to the light affecting the copy layer increases with exposure. The two layers may possess similar sensitiveness and may be composed of the same diazo compound, the concentration in the copying layer being a fraction of that in the interposed layer. The latter may be constituted by a foil of cellulose hydrate, gelatin, or a cellulose ester which may be saponified superficially. The diazo compound may be painted on or incorponated in the body of the layer. It may also be applied to the reverse side of the support of the copy layer. In examples, (1) cellulose hydrate foil is sensitized with the sodium salt of diazo-1-amino-2- naphthol- 4 - sulphonic acid, phloroglucine, titanium potassium oxalate, glycerine, and lactic acid and exposed through a layer of the same diazo compound, tartaric acid, and glycerine; (2) a layer sensitized as in example (1) is exposed through a layer containing the zinc chloride double salt of diazo-2-amino-5-ethylamino-1-toluene, tartaric acid, and glycerine; (3) a layer sensitized as in (1) with the addition of phloroglucine and exposed as in (1) or (2); the interposed layer in example (1) is applied to the reverse side of material as in (1); and (5) the copying material comprises the zinc chloride double salt of diazo-1-amino-2-methyl-4-diethylaniline, tartaric and boric acids, thiourea, resorcin, and glycerine and exposed through a layer of the same diazo compound, tartaric acid, and glycerine.