http://rdf.ncbi.nlm.nih.gov/pubchem/patent/JP-S6468342-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_d9cb217f83556ce2a418344c2d485415 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-54 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-52 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C69-80 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C67-343 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C69-76 |
| filingDate | 1987-09-09-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_bc5bc4c3944547cbdea1497a62c87b67 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_3f1e7135990d3463b636d8daba0a6bc7 http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_f04bb98b93523dbb68897dc8ee5e44e6 |
| publicationDate | 1989-03-14-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | JP-S6468342-A |
| titleOfInvention | Method for separating and purifying 3,4,3',4'-biphenyltetracarboxylic acid tetraester |
| abstract | PURPOSE:To advantageously obtain the titled compound which is a raw material monomer for aromatic polyimides, by dimerizing an o-phthalic acid diester and subjecting the resultant reaction product mixture with a specific content or below of the unreacted o-phthalic acid diester available from the dimerization reaction solution to crystallization operation under specific condition. CONSTITUTION:A mixture of products obtained by dimerizing an o-phthalic acid diester is introduced into a thin-film evaporator 12 to distill off the unreacted o-phthalic acid diester from a line 13 and adjust the unreacted raw material in the residual solution to <=1.0wt.%, preferably <=0.5wt.%. The resultant reaction product mixture is then fed from a line 14 to a thin-film evaporator 15 to reduce the content of high-boiling products in the mixture. The obtained mixture is subsequently introduced from a line 16 into a mixer 17 for a crystallizing solvent and mixed with the crystallizing solvent fed from a line 19. The mixed solution is subsequently transferred to a crystallizer 20, selectively crystallized and then centrifuged in a centrifugal separator 21 to afford crystals of the aimed compound from a line 22. The crystallizing operation is preferably carried out at 25-50 deg.C. |
| priorityDate | 1987-09-09-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 23.