http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-521837-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_4082ec022e589cfca9224bba971a4ab2 http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_8999c2690be1f24bc507147c504c85c4 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G03C7-26 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03C7-26 |
| filingDate | 1938-10-22-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1940-05-31-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-521837-A |
| titleOfInvention | Production of coloured pictures |
| abstract | 521,837. Colour photography. SCHINZEL, K., and SCHINZEL, L. Oct. 22, 1938, No. 32576/39. Convention date, Oct. 22, 1937, Divided out of 521,746. [Class 98 (ii)] A three-colour photograph is produced in an exposed and developed material having on a single support three differentially colour sensitized silver halide emulsions at least one of which contains a dye or organic compound which on oxidation, reduction, or hydrolysis gives a dye by a process which includes the steps of diffusely forming in the emulsions a water-insoluble reducing agent and then treating the material with weak alkali to cause the reducing agent so formed to be locally oxidized 'by the residual silver halide. The reducing agent may be locally oxidized by treatment with weak alkali, and the regenerated dye reduced by the reducing agent remaining in the areas free from silver halide and removed bv treatment with stronger alkali, or in a modification may be locally oxidized to an oxidizing agent by treatment with weak alkali and the oxidizing agent caused to oxidize the dye, leuco dye, or organic derivative of the dye in the areas where residual silver halide was present by treatment with acid. The latent images are developed with a neutral developer. The insoluble reducing agents ferrous, manganous, titanous, or stannous ferrocyanide may be formed in the emulsion by double decomposition, and reduce residual silver chloride or bromide after exposure or treatment with thiourea or similar fogging agents. Treatment with sodium hydroxide or carbonate, optionally in the absence of oxygen and in presence of accelerating agents such as Induline Scarlet, hydroquinone, Safranine or anthraquinone dyes and their sulphonic and carboxylic acids reduces the dyes in the areas of the silver image. The reduced silver and metal hydroxide are removed by Farmer's reducer or acid oxidizing baths. Insoluble salts of hydrosulphite or condensation products of hydrosulphurous acid with ketones or aldehydes may be diffusely precipitated in the emulsion. Manganous or ferrous phosphates may also be used. In the modification ferric or manganic hydroxide is formed in the areas where silver is present and used for the oxidation of leuco derivatives after acidification in the absence of oxygen. The silver may first be converted to silver ferrocyanide..The photographic material and dyes are identical with or similar to those described in Specification 521,888. Specifications 500,826, 503,752, 512,559, and 520,173 also are referred to. |
| priorityDate | 1937-10-22-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 45.