Patent GB-1292616-A (GB)
Title: Photographic physical development process
Inventor: BASS JON DOLF
IPC: G03C1/72
Filed: 1969-10-01
Abstract: 1292616 Photographic physical development EASTMAN KODAK CO 1 Oct 1969 [1 Oct 1968] 48305/69 Heading G2C A photographic record is produced by imagewise exposing a layer containing a radiationsensitive silver-dye complex to form an imagewise distribution of physical development nuclei therein and physically developing the nuclei by depositing silver thereon from a stable (i.e. a photographic material in which the complex is incorporated does not show, compared with a control material, an undesired loss in photographic speed and/or density after being kept for a few days at 50 C. and 50% relative humidity) complex of silver and an organic compound which is: (a) a thiazoline thione or thiazolidine thione, (b) a thiopyrimidine, (c) a dithiocarbamate in the formula:- wherein each of R 1  and R 2  is H, alkyl, alkylene, acyl, or aryl; and R 12  is alkyl, aryl or carboxyaralkyl, (d) a thiourea derivative in the formula:- wherein each of R 1 , R 2 , R 4  and R 5  is H, alkyl, alkylene, acyl or aryl; and R 2  and R 5  may be joined to form a heterocyclic ring and may in that case be -CO-CH=CH-, -CO-CR 1 R 2 -CO-, -CO-CR 1 R 2 - or -CH(R 1 )-CH(R 2 ), (e) an imidazoline or imidazolidine, (f) an isothiourea derivative in the formula:- [H 2 N-C(NH)-SR 1 ]Ag wherein R 1  is alkyl, alkylene, acyl or aryl, (g) a mercaptocarboxylic acid, (h) a mercaptoalkylcarboxamide, (i) an alkyne compound in the formula:- wherein R 15  is H, aryl, alkyl, alicyclic or akylene forming a ring with R 16 ; R 16  is H, aryl, alkyl or alkylene forming a ring with R 15 , R 17  is -OR 18 , -S-R 19 , -NR 20 R 21  or an alkylene oxide polymer adduct of the formula:- -O(CH 2 CH 2 O) n H wherein n is an integer; and R 18 , R 19 , R 20  and R 21  are each H, acyl or alkyl; (j) a hydroxy-carboxylic acid in the formula:- [HO-W-COOH]Ag wherein W is alkylene or a heterocyclic group, (k) a thia-alkyl compound in one of the formulae:- [X-S-Z]Ag, [X-S-S-Z]Ag and wherein X and Z are each heterocyclic, aryl, alkyl or acyl; Z' is Z or H; n is a number; and Y is alkylene, (1) a phenylenedioxy di(alkylcarboxylic acid), (m) a polymer having a ligand atom for silver, or (n) one of the compounds:- 1,10-phenanthroline, 1-(4-carboxyphenyl)-3, 5- dimethyl-4-phenylpyrazole, sodium dicyanamide, 8-hydroxyquinoline, 8-hydroxy-quinoline sulphate, saccharin, pseudothiohydontoin, 2, 4-thiazolidinedione, 5-sulphobenzotriazole, oxalic acid, 3, 5- dihydroxy-benzoic acid or succinic acid. Many examples of these complexes are given. The stable complex of silver and the organic compound may be incorporated in the sensitive layer or in a water-permeable layer adjacent thereto (see Examples). Physical development may be carried out in a colour developer in the presence of a colour coupler to form a dye and a silver image, the latter being removed by bleaching and fixing (see Examples 4 to 9). In Examples 5 and 6 the exposed material is black and white developed, bleached in aqueous acidic potassium permanganate solution, rinsed and cleared in 2% sodium bisulphite solution, exposed to white light and colour developed. In Example 3 a silver salt diffusion transfer process is described using a material containing the silver-dye complex and the stable complex of silver and an organic compound. Example 11 describes the use of a similar material additionally containing dye-sensitized titanium dioxide as a radiation sensitive component. The alkyl, alkylene, acyl and aryl groups referred to in the Specification may contain various substituents which do not adversely affect the stability and availability of silver for physical development of the described complexes, e.g. carboxyl, hydroxyl or sulphonic acid groups.