GB1222675A - Light sensitive compositions and photographc elements comprising the same - Google Patents

Abstract

1,222,675. Photo-sensitive compositions. MONSANTO CO. June 6, 1968 [June 7, 1967], No.27082/68. Heading G2C. Photo-sensitive compositions comprise (1) an oxidizable ethylenically unsaturated material having a M.Wt. of at least 140, and (2) a photo-sensitizer which on exposure to I. R. , visible or U. V. radiation causes atmospheric oxidation of (1). The imagewise exposed compositions may be developed by either (i) a solution or dispersion of a dye or other coloured or colour-forming material (e.g. a Fe (III) chelate of 8-hydroxyquinoline, which may be after-treated with KOH to form iron oxide, AgNO 3 which is after-treated with HC1 and light, or KOH which is after-treated with hydroquinone and AgNO 3 ), (ii) a solid material, e.g. graphite, or (iii) a solvent for the unoxidized areas (when the composition is on a natural rubber substrate); the images formed by dye development may be toned by after-treatment with a second dye, and those formed by a graphite development by copper electro-plating. Images may also be formed by uniformly exposing but preventing atmospheric oxidation in certain areas, e. g. by a plastics sheet or drops of water. The unsaturated material may be an optionally modified naturally occurring substance, e.g. a rosin, fatty oil or natural rubber, a long chain unsaturated hydrocarbon or a homo- or co-polymer of a diolefine. The sensitizer is preferably a porphin-type compound, or a fluorescein-type or triarylmethane dye. The compositions are preferably coated on a support and may further contain a polymer free from ethylenic unsaturation, tetrasodium polyphosphate, clay, TiO 2 , a C 18 hydrocarbon and/or a chlorinated polyphenyl.