Patents by Inventor Hefu Li

Hefu Li has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11059772
    Abstract: Disclosed is an imine-type quaternary ammonium salt catalyst, wherein the catalyst has a general structure formula shown by formula I below; in the formula, R1 and R2, respectively, are independently selected from a C1-C20 linear alkyl or a branched C3-C20 alkyl, and a C1-C20 hydroxylalkyl, a C3-C8 cycloalkyl, and arylated alkyl; R3 is a linear or branched alkyl, cycloalkyl or aryl; and R4 is hydrogen, aryl, a linear C1-C15 alkyl or branched C3-C15 alkyl. Also disclosed are a method for preparing the catalyst and a polyisocyanate composition prepared therefrom. The catalyst, by introducing an imine structure, on the basis of ensuring high catalytic activity thereof, is allowed to have properties of high temperature decomposition and inactivation, and when applied to the synthesis of polyisocyanate, can effectively prevent the risk of explosive polymerization caused by an uncontrolled reaction.
    Type: Grant
    Filed: February 13, 2018
    Date of Patent: July 13, 2021
    Inventors: Nuancheng Wang, Yonghua Shang, Yuqi Wang, Bin Shi, Zhicheng Zhu, Hefu Li, Yuan Li, Weiqi Hua
  • Publication number: 20200377445
    Abstract: Disclosed is an imine-type quaternary ammonium salt catalyst, wherein the catalyst has a general structure formula shown by formula I below; in the formula, R1 and R2, respectively, are independently selected from a C1-C20 linear alkyl or a branched C3-C20 alkyl, and a C1-C20 hydroxylalkyl, a C3-C8 cycloalkyl, and arylated alkyl; R3 is a linear or branched alkyl, cycloalkyl or aryl; and R4 is hydrogen, aryl, a linear C1-C15 alkyl or branched C3-C15 alkyl. Also disclosed are a method for preparing the catalyst and a polyisocyanate composition prepared therefrom. The catalyst, by introducing an imine structure, on the basis of ensuring high catalytic activity thereof, is allowed to have properties of high temperature decomposition and inactivation, and when applied to the synthesis of polyisocyanate, can effectively prevent the risk of explosive polymerization caused by an uncontrolled reaction.
    Type: Application
    Filed: February 13, 2018
    Publication date: December 3, 2020
    Applicant: Wanhua Chemical Group Co., Ltd.
    Inventors: Nuancheng Wang, Yonghua Shang, Yuqi Wang, Bin Shi, Zhicheng Zhu, Hefu Li, Yuan Li, Weiqi Hua