Patent ID: 8093434

Claim:
A method of producing a crystal polymorph of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, comprising the steps of reacting fluorenone and 2-phenoxyethanol in the presence of a heteropolyacid, initiating deposition of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene at lower than 50° C. from the resultant mixture to obtain a crude product of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, dissolving the crude product in at least one solvent selected from the group consisting of aromatic hydrocarbon solvents, ketone solvents and ester solvents, and initiating deposition of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene at 50° C. or higher.