GB1383679A - Process for development of two-component diazotype photosensitive materials - Google Patents

Abstract

1383679 Developing two-component diazotype materials MITA INDUSTRIAL CO Ltd 27 July 1972 [31 July 1971 26 Nov 1971] 35237/72 Heading G2C Exposed two-component diazotype materials are developed by applying thereto an aqueous developer comprising 5-60 wt per cent of an alkali metal or alkaline earth metal salt of a carboxylic acid and not containing a coupler and then heating to between 70 and 120 C. The acid may be an aliphatic, aromatic, araliphatic or heterocyclic mono-or polycarboxylic acid or an alicyclic monocarboxylic acid. Preferred salts are sodium, potassium, lithium and calcium acetate, sodium mono- and trichloroacetate, sodium or potassium formate, sodium, magnesium or sodium potassium tartrate, sodium or magnesium benzoate and sodium salicylate or oleate. The developer may also contain a mono-or polyhydric alcohol, a surfactant, a polymer or a fluorescent dye. The diazotype material may be as set out in Specification 1292163 and may contain urea, trichloracetic acid, a dye or a urea/aldehyde resin or may be developed to produce multicolour copies as also set out in Specification 1292163. Alternatively, multi-colour copies may be produced by using a material containing a diazonaphthol sulphonic acid when on exposure through a faint image (e.g. a pencil image) generates a coupler and couples with the undecomposed diazo compound and also containing another diazonium salt and a coupler which couple in the normal way in the unexposed areas under dense image (e.g. an ink image). The diazotype layer may be coated on a support coated with a butadiene/methyl methacrylate copolymer.