http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1340131-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_5d9f3ca41550d315642580237250c5b0 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G03C7-421 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03C5-44 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03C7-42 |
| filingDate | 1971-04-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1973-12-12-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1340131-A |
| titleOfInvention | Photographic bleach-fix composition |
| abstract | 1340131 Photographic silver halide bleachfix composition EASTMAN KODAK CO 19 April 1971 [23 March 1970] 24555/71 Heading G2C An aqueous photographic bleach-fix solution comprises (A) 0À4 to 2À0 moles/litre of a watersoluble silver bleaching agent having an alkali metal, ammonium or amine cation and an anion comprising Fe (III) complexed with a polyfunctional ligand, (B) a water-soluble secondary ligand selected from a thiocyanate, borate, boric acid, fluoride or thiourea, the molar ratio of the thiocyanate to (A) being at least 5: 1, the molar ratio of borate, boric acid or fluoride to (A) being at least 1: 1 and the molar ratio of thiourea to (A) being at least 3: 1 and (C) if not already completely provided by (B), a water-soluble silver halide fixing agent in an amount of up to 1-5 moles/litre. The solution may have a pH of 5 to 9. The secondary ligand (B) may be a thiourea of the formula:- R<SP>11</SP> R<SP>10</SP> N-CS-N R<SP>8</SP>R<SP>9</SP> wherein R<SP>8</SP> and R<SP>11</SP> are each H, methyl or hydroxyethyl; R<SP>9</SP> and R<SP>10</SP> are each H, methyl, hydroxyethyl, NH 2 , NHCH 3, N(CH 3 ) 2 , NHCH 2 CH 2 OH, N(CH 2 CH 2 OH) 2 or N(CH 3 ) CH 2 CH 2 OH, the thiourea containing at least one NH group. The fixing agent (C) may be a water-soluble thiosulphate, thiocyanate, a thiourea or a thioether. The polyfunctional ligand (A) may be ethylenediamine tetraacetic acid or N-(#-hydroxyethyl) ethylenediamine triacetic acid, and many others are listed. Concentrated solutions can be made which are useful for storage and with materials having a high silver content. The secondary ligands (B) replace the watermolecule in the ferric complex (A) and prevent dimensation throughout the pH range 4 to 9. |
| priorityDate | 1970-03-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 36.