| Predicate |
Object |
| assignee |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_d648658dd620f548c24de39659a5e9e3 |
| classificationCPCInventive |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C213-10
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C303-44
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/G03C7-4136
http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C209-84 |
| classificationIPCAdditional |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C311-05
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C215-16
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C211-51 |
| classificationIPCInventive |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C213-10
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C303-44
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C209-84
http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/G03C7-413 |
| filingDate |
2002-06-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor |
http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_469af602ddccebf02cdf3514fe4f571c
http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_1f6596d1436818c091fed8a0346ccc7c |
| publicationDate |
2004-03-24-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber |
EP-1399780-A1 |
| titleOfInvention |
Method for purifying free-base p-phenylenediamine-type photographic color developers |
| abstract |
A process for purifying p-phenylenediamine color developers in their free-base form. The process includes subjecting a solution containing p-phenylenediamine-type free base color developer to short path distillation which includes at least one of falling film evaporator, thin film evaporator, wiped film evaporator, or short-path evaporator. Another aspect is a method for preparing an acid salt from a p-phenylenediamine free base color developer. The method includes the steps of: a) dissolving a purified p-phenylenediamine free base derived from the short path distillation process in an organic solvent; b) contacting the dissolved free base distillate with an appropriate mineral acid; and c) crystallizing the color developer in the acid salt form. |
| priorityDate |
2001-06-28-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type |
http://data.epo.org/linked-data/def/patent/Publication |