| 摘要 |
Light sensitive diazotype layers which contain a mixture of actively coupling diazo- and azo-components are subjected to an intense drying so as to be stable against coupling until the normal moisture content is restored. The layer may also contain acids or acid substances, substances acting on the azo component, such as hydroxylamine or semi-carbazide, or substances to prevent yellowing as in Specification 294,972, [Class 98 (ii), Photographic processes &c.]. Salts acting as buffers to the alkaline developer or forming sparingly soluble compounds with the diazo body may also be added. Examples are given of mixtures containing (1) 1-dibenzylamido benzene - 4 - diazonium chloride, phloroglucinol, resorcinol, thiocarbamide, hydroxylamine sulphate, glucose, oxalic acid, ammonium chloride and gelatine; (2) 1-di-isoamylamine benzene-4-diazonium chlorostannate, phloroglucinol, resorcinol, thiocarbamide, phosphoric acid and gelatine, both the above being developed with sodium carbonate, sodium thiosulphate and sodium citrate; (3) 3 - diazo - hexahydrocarbazol - chlorostannate, phloroglucinol, thiocarbamide, semi-carbazide chloride, hydroxylamine sulphate, tartaric acid, sodium chloride and sodium citrate, developed with a mixture of soda and sodium thiosulphate. In all cases the moisture content of the layer is reduced to below 2 per cent. Specifications 210,862, 234,818, 295,993, 330,625, and 332,552, [all in Class 98 (ii), Photographic processes &c.], also are referred to.
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