The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 25, 2003
Filed:
Jun. 22, 2000
Masahiro Iwahara, Tokuyama, JP;
Idemitsu Petrochemical Co., Ltd., Tokyo, JP;
Abstract
Provided is a process for producing bisphenol A having a stable color tone at a high temperature and free from coloration, which comprises reacting phenol with acetone in the presence of an acid ion-exchange resin as a catalyst and an alkyl mercaptan as a cocatalyst, wherein a concentration of an organosulfur compound in a crystallization starting material obtained by conducting the reaction under conditions that a reaction temperature is between 60 and 100° C., a phenol to acetone molar ratio is between 6 and 13 and an acetone to alkyl mercaptan molar ratio is between 13 and 25, distilling off unreacted acetone, by-product water and the alkyl mercaptan as the cocatalyst and further distilling off excess phenol is measured, and maintained at 200 weight ppm or less.