Patents by Inventor Seung Dai Choi

Seung Dai Choi 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).

  • Method for producing dinuclear transition metal complexes as olefin polymerization catalyst
    Patent number: 6730801
    Abstract: The object of the present invention is to provide a method for producing a dinuclear transition metal complex of formula (1) by reacting cyclopentadienyl ligand compound of formula (2) and substituted transition metal of formula (3). Cp-Si(R)2HNANHSi(R)2-Cp  (Formula 2) wherein, A represents C2-30 alkylene, substituted alkylene, arylene, substituted arylene, cycloalkylene, substituted cycloalkylene, biarylene or substituted biarylene; Cp represents a ligand compound having cyclopentadienyl skeleton selected from the group consisting of cyclopentadienyl, substituted cyclopentadienyl, indenyl, substituted indenyl, fluorenyl and substituted fluorenyl; R represents C1-20 alkyl or substituted alkyl; H represents hydrogen atom; Si represents silicon atom; and N represents nitrogen atom. M(NR2′)4  (Formula 3) M represents transition metal of Periodic Table IV selected from titanium, zirconium and hafnium; R′ represents C1-6 alkyl.
    Type: Grant
    Filed: December 11, 2002
    Date of Patent: May 4, 2004
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Eun-Il Kim, Seung Dai Choi
  • METHOD FOR PRODUCING DINUCLEAR TRANSITION METAL COMPLEXES AS OLEFIN POLYMERIZATION CATALYST
    Publication number: 20040054207
    Abstract: The object of the present invention is to provide a method for producing a dinuclear transition metal complex of formula (1) by reacting cyclopentadienyl ligand compound of formula (2) and substituted transition metal of formula (3).
    Type: Application
    Filed: December 11, 2002
    Publication date: March 18, 2004
    Applicant: KOREA KUMHO PETRO-CHEMICAL CO., LTD.
    Inventors: Eun-Il Kim, Seung Dai Choi