http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-851221-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_9799ffcda2dbb45041a5ab0fd08dd5fe |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G03C7-30 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03C7-30 |
| filingDate | 1957-07-01-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1960-10-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-851221-A |
| titleOfInvention | Photographic colour development process |
| abstract | 851,221. Colour photography. KODAK Ltd. July 1, 1957 [June 29, 1956], No. 20629/57. Class 98(2) An exposed multilayer silver halide material is black and white developed, the developed silver is oxidised and removed, the material is treated with an oxidising agent consisting of (a) a bromine solution, (b) an acid dichromate bath containing alkali metal bromide, (c) an acid solution of a ceric salt, (d) an acid solution of an alkali metal persulphate or (e) a silver removal bleach bath containing dithiac suberic acid to remove fog centres formed in the undeveloped silver halide during black and white development, the light sensitivity of the undeveloped silver halide is restored by treatment with a mild reducing agent, and the undeveloped images are then selectively re-exposed and colour developed. In Example 1 a three layer film with ultra-violet filters between the emulsion layers is so treated using acidified dichromate for removal of the black and white developed silver, bromine water for removal of the fog centres and sodium bisulphite solution as reducing agent to restore light sensitivity of the undeveloped silver halide, after which it is exposed through the support, developed in a cyan coupler-containing colour developer, bleached in ferricyanide and fixed, and is compared with a film of the same kind which is re-exposed and colour developed directly after the black and white development and then similarly bleached in ferricyanide and fixed, to show relative cyan fog densities of À06: À50 in areas of minimum cyan density. Example 2 refers to Example 1 and specifies bleach baths of the types (c) and (d) above, with which it is possible to remove both the negative silver and the fog centres in a single bath, and bisulphite again is used to restore light sensitivity. Sulphites and nitrites are mentioned as further mild reducing agents for the purpose. Specification 718,411 is referred to. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-2299681-A |
| priorityDate | 1956-06-29-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 31.