http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-857903-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_70ec63d39d6704bacc5c7068c93ded43 |
| classificationCPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C2527-054 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C2-867 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C2-86 |
| filingDate | 1959-07-08-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1961-01-04-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-857903-A |
| titleOfInvention | A process for the production of diarylmethanes |
| abstract | Diarylmethanes are produced by the condensation of an aromatic hydrocarbon with formaldehyde in the presence of aqueous sulphuric acid of 55%-70% by weight concentration by adding the feed hydrocarbon and formaldehyde continuously to the reaction mixture which is maintained at a temperature such that water and feed hydrocarbon are evaporated and withdrawn, the vapour stream is condensed and the hydrocarbon layer returned and a bleed stream is removed from the reaction mixture and from the hydrocarbon phase is separated (a) unconverted feed hydrocarbon which is returned to the reactor and (b) diarylmethane which is recovered as product. The acid catalyst may also contain 2%-10% by weight of an ether alcohol having 3 to 6 carbon atoms per molecule and 0,8%-5% by weight of a trivalent arsenic compound, e.g. sodium arsenite or arsenious oxide. Specified hydrocarbons are toluene, xylenes, 1, 2, 4-trimethylbenzene, ethylbenzene, ethyltoluenes, ethylxylenes, diethylbenzenes, cumene, isopropyltoluenes and isopropyltoluenes. The formaldehyde is preferably added in solution in the aromatic hydrocarbon or water, e.g. as a 1%-60% by weight aqueous solution, commercial formalin being preferred. Suitable ether alcohols are di- and triethylene glycol, dipropylene glycol or the methyl or ethyl ether of ethylene glycol. Suitable conditions are 100 DEG - 170 DEG C. and a molar ratio of unreacted aromatic hydrocarbon to formaldehyde of 30-2,000 : 1. The reaction mixture is preferably circulated through conduits and a vessel having stirring means. A bleed stream is taken off from the conduit, separated, unreacted aromatic hydrocarbon separated and recycled and diarylmethane recovered. Acid catalyst is also separated and recycled. Aromatic hydrocarbon is added to the conduit and formaldehyde added at a point between the point of such addition and the vessel. Any formaldehyde which is vaporised may be recovered. In the steady state the circulating mixture preferably contains 90% by weight or more of reaction products in the hydrocarbon phase and a hydrocarbon to aqueous phase volume ratio of 1 : 0,025-10, the volume of circulating emulsion to added hydrocarbon being 10-1,000 : 1. The diarylmethanes may be cracked as described in Specification 766,498 to produce the starting hydrocarbon which may be recycled and a hydrocarbon with one more methyl group. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-1269116-B |
| priorityDate | 1958-07-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 52.