Patent GB-698027-A (GB)
Title: Photographic light-sensitive diazotype material
IPC: G03C1/54
Filed: 1952-02-20
Abstract: 698,027. Photographic diazotype material. GRINTEN, L. P. F. VAN DER, GRINTEN, P. A. W. VAN DER, and GRINTEN, K. J. J. VAN DER, [trading as CHEMISCHE FABRIEK L. VAN DER GRINTEN]. Feb. 20, 1952 [March 20, 1951], No. 4502/52. Class 98(ii). Photographic diazotype material has a support bearing a one-component diazotype waterpermeable film layer suitable for development with a thin layer of an aqueous developer, the diazo compound having the general formula in which X is an anion and R 1 , R 2  are alkyl radicals containing together 10, 11 or 12 carbon atoms, each alkyl radical containing at least 4 and at most 7 carbon atoms, and not more than one of the two having a side chain attached to the alpha carbon atom. The support may be of paper, baryta-coated paper, transparent paper, linen, celluloid, cellulose acetate, plastic, metal, or glass, and the film-forming material may be of cellulose, or water-permeable cellulose or polyvinyl ester. A cellulose acetate support may be superficially deacylated to provide the permeable layer to be sensitized. A layer of film-forming material containing the diazo compound may be cast on to the support, or the film layer may be first cast on the support and subsequently impregnated with a solution of the diazo compound, or the film layer may be separately cast and transferred after drying to the support, with subsequent impregnation with the diazo compound if not originally present. A hydrophobic sublayer may be provided. In example 1, paper coated on one side with a cellulose acetate layer subsequently superficially hydrolysed is sensitized with an aqueous ethanol solution of the zinc chloride double salt of p - diazo - di - n - amylaniline, tartaric acid, and ammonium chloride. The dried and exposed material is developed in an aqueous solution of thiourea, phloroglucinol, resorcinol, potassium hydroquinone monosulphonate, sodium isopropylnaphthalenesulphonate, mannitol, potassium tetraborate pentahydrate, and potassium hydroxide. In example 2, the procedure is similar, using a sensitizing solution comprising an aqueous-ethanol solution of the zinc chloride double salt of p-diazo-sec.-amyl-nhexylaniline, citric acid, and ammonium chloride. In example 3, the sensitizing solution comprises an aqueous-ethanol solution of the zinc chloride double salt of p-diazo-di-isoamylaniline, alum, and di-ammonium citrate. In example 4, superficially saponified cellulose acetobutyrate is sensitized with an aqueousethanol solution of the zinc chloride double salt of p - diazo - di - n hexylaniline, ammonium chloride, and tartaric acid, dried, exposed, and developed as in example 1. In example 5, paper is first coated with a hydrophobic cellulose acetate layer and then with a diazotype layer formed from an aqueous-ethanol solution of the zinc chloride double salt of p-diazo-di-nhexylaniline, tartaric acid, polyvinyl acetate about 77 per cent saponified, and saponin. In example 6, a cellulose film is fixed by adhesive to paper and sensitized with an aqueous ethanol solution of the zinc chloride double salt of p-diazo-n-amyl-n-hexylaniline and citric acid. The exposed material may be developed as in example 1. Specifications 311,196, 318,511, [both in Class 98 (ii)], 496,049, 563,547, 563,804 and 656,674 are referred to.