Patent GB-1297979-A (GB)
IPC: G03C1/695
Filed: 1970-04-14
Abstract: 1297979 Photographic dry copying process using light-sensitive azides AGFA-GEVAERT A G 14 April 1970 [14 April 1969 21 May 1969] 17664/70 Heading G2C A light-sensitive photographic material comprises a light-sensitive layer which contains (a) at least one light-sensitive aryl or heterocyclic azide, containing at least one azido group, and in which the azido group is attached to the aryl or heterocyclic ring either directly or via a carbonyl group and (b) at least one phenol or naphthol which is capable of being transferred to an adjacent image-receiving layer at temperatures between 80‹ and 200‹C. and forming a coloured image thereon; the light-sensitive layer containing no colour developing agent and neither the azide (a) or the phenol or naphthol, (b) being capable of acting as a colour developing agent. The organic azido compound 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 a -C 6 H 4 - CO-CH 2 - group; R 1  and R 2  are each hydrogen, a saturated or olefinically unsaturated aliphatic group, an aryl group, an amino group which may be substituted with an alkyl or acyl group, a halogen atom, OH, an alkoxy group, a carboxyl group, an esterified carboxyl group, a carbamoyl group, a sulphonic acid group, a sulphonamide group, a nitrile group or R 1  and R 2  together may complete a fused benzene or naphthalene ring; m is 0 or 1; and n is 0 or 1. Z may complete an oxazole, thiazole, selenazole, imidazole, pyridine, pyrrole or pyrimidine ring. The organic azido compound is preferably 9-azidoacridine, 9- azido-2,3-benzoacridine, 4-azidoquinoline or a derivative thereof having the same basic structure. The phenol or naphthol may contain at least two phenolic hydroxy groups, which may be partly etherified. An amino or hydroxy group may be ortho or para to a phenolic hydroxy group on the phenol or naphthol. The naphthol is preferably a 4- or 5-alkoxynaphth-1-ol. The light-sensitive layer may contain a polymethine or merocyanine sensitizer. The image-receiving layer may contain a heavy metal compound (which is a compound of a metal of Groups IIIa to Va, Ib, IIb and VIb to VIII of the Periodic Table in "German/ English Chemical Terminology" by King and Fromherz, Verlag Chemie, G.m.b.H., Weinheim 1963 4th Edition pages 48-49) which is not light-sensitive under the conditions of the process (see below) e.g. a silver salt of an aliphatic carboxylic acid having 8 to 24 carbon atoms which may be substituted with a thioether group. The present invention also comprises a process in which a light-sensitive layer comprising at least one light-sensitive organic azido compound and at least one image-producing compound which is a phenol or naphthol which can be transferred to an image-receiving layer between 80‹ and 200‹C., is imagewise exposed so that in the exposed areas the azido compound reacts with the phenol or naphthol to render it non- transferable, and in which the exposed layer is brought into contact with an image-receiving layer which contains at least one compound which will react with the transferred phenol or naphthol to form a coloured reaction product and the layers are heated whilst in contact to a temperature at which the phenol or naphthol in the unexposed areas of the image is transferred to the imagereceiving layer. Alternatively the imagereceiving layer may not contain any compound which will react with the transferred phenol or naphthol, but the phenol or naphthol used will itself produce coloured products on heating, either alone or in the presence of atmospheric oxygen.