Patent ID: 6165382
Filing Date: 2000-12-26
Classification: C08G,C09K

Abstract:
A process for obtaining cholesteric liquid crystals, the process comprising the steps ofpreparing a mixture by adding 4,4'-dioxyterephtaloyl dibenzoic acid dichloride and Dl-treo-1,2-butadiol to Cl-naphthalene and passing a nitrogen stream through the mixture, at room temperature for more than 35 minutes;heating the mixture above 100.degree. C. in a nitrogen stream for more than 3 hours;settling the mixture in toluene, filtering, drying with a vacuum pump and washing with ethanol in order to remove the Cl-naphthalene; whereby PTOBEE (C.sub.26 H.sub.20 O.sub.8).sub.n polymer is obtained;keeping the toluene dissolution resulting from settling the PTOBEE polymer in an airtight space; andobtaining (-) PTOBEE from the dissolution by precipitation, filtering and drying.