http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-618113-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_bd39076e1745a6d29360c58ce0ba5678 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G03F5-20 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03F5-20 |
| filingDate | 1946-10-21-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1949-02-16-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-618113-A |
| titleOfInvention | Method of preparing photographic positive transparencies and intaglio printing surfaces |
| abstract | 618,113. Photo-mechanical printing surfaces. CROWELL - COLLIER PUBLISHING CO. Oct. 21, 1946, No. 31258. Convention date, Nov. 20, 1945. [Class 98 (ii)] A screened positive transparency which has discrete silver dots of varying sizes, formed as by use of a reduced screen distance and exposure time, is subjected to the action of a bleaching medium to completely or partially bleach the dots and is then redeveloped in a colour developer to impart colour to the bleached dots or bleached portions of the dots, and such is used for preparation of an intaglio printing surface by known photographic and etching methods. The screened positive may be made from an ordinary photographic negative of a subject, or from a separation negative of one of the colours of a coloured subject; and is bleached as by use of a potassium bromidepotassium ferricyanide solution for a time sufficient to permit only the peripheries of the larger dots to be bleached; redeveloped as by a solution containing p-amino-diethylaniline monohydrochloride as colour developer and p-nitrophenylacetonitrile as colour coupler which produces magenta in the bleached areas; and cleared as by Farmer's Reducer for a time insufficient to reduce the size and opacity of the centres of the larger dots; all of these operations being carried out under observation in bright light and requiring times of treatment such as 20 to 100 seconds. In the drawing, Fig. 1 represents the subject, Fig. 2 a screened positive transparency of such, Fig. 3 this positive as modified by the invention and indicating coloured areas of dots by hatched lines; and Figs. 4 and 5 plan and section views respectively of an intaglio printing surface produced from the modified positive of Fig. 3. |
| priorityDate | 1945-11-20-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 20.