http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1049038-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_c7ad58d3c0b071069a8ee0cb8c8ba2e8 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08G77-36 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C08G77-32 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C08G77-36 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C08G77-32 |
| filingDate | 1964-08-04-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1966-11-23-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1049038-A |
| titleOfInvention | Process for isolating terminally carbofunctional organopolysiloxanes of a specified degree of polymerisation |
| abstract | In making siloxanes having terminal carbofunctional radicals by known processes, the siloxane mixtures so obtained are separated into individual polymers by adding to the mixture water and a water-miscible polar solvent which is capable of dissolving at least the lower polymers, separating the two phases and recovering the siloxane from at least one of the phases. Solvents specified are ethanol, tetrahydrofuran and dioxan, and the functional radicals specified are halohydrocarbon, hydroxy ether or thioether, cyanoalkyl and carboxyalkyl. In one embodiment, the siloxane mixture is first dissolved in the solvent and a little water is then added; two phases are obtained and separated, the heavier phase containing water, a little solvent and the siloxane component of the greatest molecular wt.; this process can be repeated until the mixture has been separated into fractions of siloxanes of different molecular wts. In another embodiment a mixture of solvent and water is added to the siloxane mixture and, beginning with the siloxane having the smallest molecular wt., individual siloxanes are extracted successively. If desired, coarser fractions or only one fraction may be extracted. In a typical Example (1) 2 mls. of water were added to 150 g. of a chloromethyl-terminated dimethylpolysiloxane mixture dissolved in 300 g. of ethanol, and the resulting mixture was shaken and allowed to settle into two layers, the lower of which was separated and freed of volatiles to yield an oil; this process was repeated with the remaining solution to yield various fractions of decreasing molecular wts. |
| priorityDate | 1963-07-30-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 25.