Patents by Inventor Wandee THUAMTHONG

Wandee THUAMTHONG 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: 10975189
    Abstract: The present invention is to provide a process for producing an oxymethylene copolymer, in which deteriorate due to oxidation hardly occurs, an amount of formaldehyde generated from the product when stored for a long time under environment of high temperature and high humidity is reduced, and occurrence of mold deposit during molding is small. A process for producing an oxymethylene copolymer includes Step 1 of polymerizing polymer raw materials containing trioxane and a comonomer in the presence of a specific amount of an acid catalyst, Step 2 of adding a hydroxylamine compound represented by the following general formula (1): to a product obtained in the Step 1 in an amount of 1 to 20-fold mol based on an amount of the acid catalyst and mixing these, and Step 3 of further melting and kneading a mixture of the product and the hydroxylamine compound obtained in the Step 2.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: April 13, 2021
    Assignees: MITSUBISHI GAS CHEMICAL COMPANY, INC., THAI POLYACETAL CO., LTD.
    Inventors: Yuuta Yamamoto, Daisuke Sunaga, Akira Ito, Wandee Thuamthong, Yupin Pattamamongkolchai
  • Publication number: 20200216598
    Abstract: The present invention is to provide a process for producing an oxymethylene copolymer, in which deteriorate due to oxidation hardly occurs, an amount of formaldehyde generated from the product when stored for a long time under environment of high temperature and high humidity is reduced, and occurrence of mold deposit during molding is small. A process for producing an oxymethylene copolymer includes Step 1 of polymerizing polymer raw materials containing trioxane and a comonomer in the presence of a specific amount of an acid catalyst, Step 2 of adding a hydroxylamine compound represented by the following general formula (1): to a product obtained in the Step 1 in an amount of 1 to 20-fold mol based on an amount of the acid catalyst and mixing these, and Step 3 of further melting and kneading a mixture of the product and the hydroxylamine compound obtained in the Step 2.
    Type: Application
    Filed: March 13, 2017
    Publication date: July 9, 2020
    Applicants: MITSUBISHI GAS CHEMICAL COMPANY, INC., THAI POLYACETAL CO., LTD.
    Inventors: Yuuta YAMAMOTO, Daisuke SUNAGA, Akira ITO, Wandee THUAMTHONG, Yupin PATTAMAMONGKOLCHAI