GB1234244A - - Google Patents

Abstract

1,234,244. Photographic diazotyle materials. KALLE A, G, Aug. 6, 1968 [Aug. 8, 1967], No.37397/68. Heading G2C. A process for fixing images, which have been produced by imagewise exposing a light-sensitive material containing a diazo sulphonate with no basic N-atom in the 4-position and a coupler, comprises treating the image with an aqueous solution containing a non-volatile acid with a pH between 1 and 4 followed by uniform exposure to actinic light. The diazo sulphonates are preferably those which are derived from benzene diazonium compounds which are not substituted in the same position to the diazo group with a nitrogencontaining substituent in which the nitrogen atom links with the carbon atom of the benzene ring but 4-acylamino-diazosulphonates may be used. The invention also relates to a diazotyle material having a layer containing a benzene diazonium sulphonate with no basic N-atom in the 4-position to the diazo group and a coupler of formula:- wherein R 1 is hydroxyalkyl or hydroxy-alkoxyalkyl, R 2 is hydrogen or hydroxyalkyl and R 3 is hydroxy, hologen or alkoxy. The light-sensitive material preferably contains lactose, an acid amide as disclosed in Specification 1, 173, 041 and caffeine. The preferred fixing solution is citric acid and zinc chloride but other acids such as tartaric, oxalic, mono- or tri-chloroacetic, succinic, methane or benzene sulphonic or phosphoric acid may be used. The light-sensitive layer may contain a coupler, such as 4, 6-dichlororesorienol, instead of a napthol as above in the above, fixing process.