Patent GB-1485379-A (GB)
Title: Photographic recording and reproduction of information
IPC: C07C43/205
Filed: 1973-12-19
Abstract: 1485379 Photo-sensitive material AGFAGEVAERT 9 Dec 1974 [19 Dec 1973] 58782/73 Heading G2C A photo-sensitive material that is capable of producing directly a visible image as a result of imagewise exposure to activating electro-magnetic radiation contains as image-forming substances an nitriniate mixture consisting of (1) at least one ultraviolet radiation-sensitive polyhalogen compound of the Formula:- wherein A, B, X and Y are halogen atoms of the group of chlorine, bromine or iodine or wherein one of A, B, X or Y represents an alkyl substituted alkyl, aryl, substituted aryl or an aroyl group, and the other groups chlorine, bromine or iodine, and (2) a dye precursor compound which does not contain an acid constituent corresponding to the general Formula:- wherein R 1  represents (1) a substituted aryl group, at least one substituent of the substituted aryl group being an ether group R 6-0-  in which R 6  represents a hydrocarbon group or a substituted hydrocarbon group or (2) a heterocyclic or substituted heterocyclic group, R 2  represents (1) a substituted aryl group, at least one substituent of the substituted aryl group being an ether group R 6-0-  in which R 6  represents a substituted or unsubstituted hydrocarbon group, (2) a substituted or unsubstituted heterocyclic group or (3) a -CH=CZ group in which Z represents a divalent radical containing one or more hetero atoms which together with the adjacent carbon atom forms a heterocyclic nucleus, R 3  represents (1) a -XH or -XR 7  group in which X is oxygen and R 7  is an organic group, (2) a -N@ group wherein each of R 8  and R 9 , which may be the same or different, represents hydrogen or an alkyl, cycloalkyl, aralkyl or aryl group, or R 8  and R 9  together represent the necessary atoms to close a nitrogen-containing heterocyclic nucleus, each of R 4  and R 5  represents hydrogen, a C 1  to C 5  alkyl or cycloalkyl, aralkyl or aryl group, n is 0 or 1 or m is 0 or 1. A visible image can be formed directly, by exposure to a sufficient radiation close. In an alternative method the material is informationwise exposed to activating radiation of a close sufficient to bring about a latent or barely visible image, the image portions of which have a spectral sensitivity in a wavelength range outside the inherent sensitivity range of the polyhalogen compound, and the imagewise exposed material is then exposed to light within the wavelength range for which the initially exposed portions are more sensitive than the initially non-exposed portions, to bring about the formation of a visible image. It is considered that the dye of the initially formed image acts as a sensitizing agent for a chemical reaction between the polyhalogen compound and the dye precursor during the overall exposure. Alternatively the recording material is first overall exposed to radiation to produce latent dyestuff over the whole layer and then exposure is effected information-wise with radiation in the absorption band of the dyestuff. Simultaneous heating, e.g. by overall infrared exposure, is optionally carried out. Poly-N-vinyl-carbazole and antifoggants e.g. triphenylstibine can be added and substances containing Pb, Hg, Bi, Ba and/or W can be incorporated for high energy absorption, e.g. x-ray and laser beam recording. The materials may be applied to the back of magnetic recording tape.