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:
Feb. 03, 2015
Filed:
Nov. 04, 2010
Zhendong Zhao, Jiangsu, CN;
Xingdi LI, Jiangsu, CN;
Liangwu BI, Jiangsu, CN;
Yuxiang Chen, Jiangsu, CN;
Yan Gu, Jiangsu, CN;
Dongmei LI, Jiangsu, CN;
Jing Wang, Jiangsu, CN;
Zhendong Zhao, Jiangsu, CN;
Xingdi Li, Jiangsu, CN;
Liangwu Bi, Jiangsu, CN;
Yuxiang Chen, Jiangsu, CN;
Yan Gu, Jiangsu, CN;
Dongmei Li, Jiangsu, CN;
Jing Wang, Jiangsu, CN;
Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing, Jiangsu, CN;
Abstract
Disclosed is a process for preparing isopimaric acid, comprising the following steps: First step: dissolving thermally isomerized rosin in acetone, adding in drops a solution of isobutanolamine in acetone to form a precipitate, standing, filtering, washing with ethanol, and drying to obtain crude ammonium salt of isopimaric acid; recrystallizing the crude ammonium salt of isopimaric acid according to multi-recrystallization, and drying to obtain purified crystal of ammonium salt of isopimaric acid; Second step: dissolving the purified crystal of ammonium salt of isopimaric acid obtained in the first step in ether, adding hydrochloric acid in portions until the crystal of ammonium salt of isopimaric acid disappears, removing a water layer and washing the ether layer with water to neutral, evaporating the ether, dissolving the residue in acetone, adding water slowly into the solution dropwise until crystals cease to grow, then filtering and drying to obtain purified isopimaric acid.