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:
Mar. 26, 2024
Filed:
Dec. 25, 2018
Wanhua Chemical Group Co., Ltd., Shandong, CN;
Yong Yu, Shandong, CN;
Yonghua Shang, Shandong, CN;
Lei Zhao, Shandong, CN;
Wenbin Li, Shandong, CN;
Ye Sun, Shandong, CN;
Wei He, Shandong, CN;
Xuelei Cui, Shandong, CN;
Jingxu Wang, Shandong, CN;
Degang Liu, Shandong, CN;
Yuan Li, Shandong, CN;
WANHUA CHEMICAL GROUP CO., LTD., Shandong, CN;
Abstract
A method for preparing isophorone diisocyanate by (1) reacting isophorone with hydrogen cyanide in the presence of a catalyst to obtain isophorone nitrile; (2) reacting the isophorone nitrile obtained in step (1) with ammonia gas and hydrogen in the presence of a catalyst to obtain isophorone diamine; and (3) subjecting the isophorone diamine to a phosgenation reaction to obtain the isophorone diisocyanate, wherein the content of impurities containing a secondary amine group in the isophorone diamine that undergoes the phosgenation reaction in step (3) is ≤0.5 wt. The method reduces the content of hydrolyzed chlorine in the isophorone diisocyanate product, improves the yellowing resistance of the product, and the harm due to presence of hydrolyzed chlorine in the product is reduced.