Patent GB-1315707-A (GB)
Title: Photographic dry copying process
IPC: G03C1/695
Filed: 1970-05-15
Abstract: 1315707 Photographic dry copying process AGFA-GEVAERT A G 15 May 1970 [24 May 1969] 23659/70 Heading G2C A light-sensitive layer containing a lightsensitive organic azido compound and a hydroxylamine derivative having a melting point of above 50‹ C and (i) corresponding to the formula:- HO-N (R 3  )-CO-R 4  wherein R 3  is H or alkyl and R 4  is 1-5C alkoxy, aryloxy, amino, alkylamino or arylamino; or (ii) being N-methyl-N- morpholinomethyl hydroxylamine, N-allyl-N' - hydroxy urea, 1,1,3-tri(hydroxylamino)-3 - phenyl-propanol or α-hydroxylaminobutyric acid; which derivative can be transferred upon heating between 80‹ and 200‹C to an image-receiving layer is imagewise exposed, the hydroxylamine derivative in the exposed areas is converted into a non-transferable compound by reaction with the azido compound, the exposed layer is contacted with an image-receiving layer containing at least one compound capable of reacting with the transferred hydroxylamine derivative to form a coloured reaction product and the layers in contact are heated to transfer the hydroxylamine derivative from the unexposed areas of the lightsensitive layer to the image-receiving layer. The organic azido compound may be a heterocyclic or aryl azide containing at least one azido group and in which the azido group is attached to the heterocyclic or aryl ring directly or via a carbonyl or sulphonyl group, and may have the formula:- wherein Z completes a 5-or 6-membered N- containing heterocyclic ring, which ring may have fused thereto a benzene or naphthalene ring which may be substituted; Y is arylene or -C 6 H 4 -CO-CH 2 -; R 1  or R 2  is H, a saturated or an olefinically unsaturated aliphatic group, aryl, amino which may be substituted with alkyl or acyl, halogen, OH, alkoxy, carboxyl, esterfied carboxyl, carbamoyl, sulphonic acid, sulphonamido or nitrile; R 1  and R 2  together may complete a fused benzene or naphthalene ring; n is 0 or 1; and m is 0 or 1. The azide may be 2-methyl-4- azido-7-dimethylamino-quinoline, 9-azidoacridine, 3-dimethylamino-9-azidoacridine, bis-[4- azidostyryl]-ketone, 2, 6-bis-[3-azidobenzylidene] cyclohexanone (m.p. 80-85‹C), 2, 6-bis-[4- azidobenzylidene] cyclohexanone or 2-p-toluenesulphamido-9-azidoacridine. The light-sensitive layer may contain as sensitizer a polymethine dye or a compound of the formula:- wherein X is 5 or Se; Z completes a 5- or 6- membered non-metallic heterocyclic ring which may contain a fused benzene or napthalene ring; R is a saturated or olefinically unsaturated aliphatic group or cycloalkyl, aralykl or phenyl; R<SP>I</SP> and R<SP>II</SP> are each H or alkyl; R<SP>III</SP> and R<SP>17</SP> are each H, a saturated or olefinically unsaturated aliphatic group, cycloalkyl, aryl, aralkyl or heterocyclyl; and R<SP>III</SP> and R<SP>IV</SP> together may complete a saturated 5- or 6- or 7-membered heterocyclic ring; and n is 1 or 2. The light-sensitive layer may be coated on a paper support. The binder for the light-sensitive layer may be polyvinyl chloride or ethyl cellulose, and for the imagereceiving layer polyvinyl acetate and acetyl cellulose or polyvinyl alcohol. Exposure may be given with a mercury or iodine quartz lamp. The image-receiving layer may contain a heavy metal compound such as cupric chloride, bismuth nitrate, silver behenate, silver stearate, or silver salts of octadecylmercapto-acetic acid or 2-octadecylmercapto-5-carboxy-methylmercapto -1, 3, 4-thiadiazole. Brown positive images are obtained in the examples.