Patents by Inventor Sang-Doo Ahn

Sang-Doo Ahn 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: 7989571
    Abstract: Disclosed is a method for producing a norbornene monomer composition, a norbornene polymer produced using the norbornene monomer composition, an optical film including the norbornene polymer, and a method for producing the norbornene polymer. The method includes reacting a reaction solution that contains cyclopentadiene, dicyclopentadiene, or a mixture of cyclopentadiene and dicyclopentadiene, an acetate compound, and a solvent so that a content of an exo isomer is 50 mol % or more. Variables such as a reaction temperature, a reaction time, a molar ratio between reactants, and addition of a solvent are controlled so that the exo isomer is contained in content of 50 mol % or more. Accordingly, it is possible to industrially produce an acetate norbornene addition polymer by using the acetate norbornene monomer composition containing the exo isomer in content of 50 mol % or more.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: August 2, 2011
    Assignee: LG Chem, Ltd.
    Inventors: Sung-Ho Chun, Won-Kook Kim, Sung-Cheol Yoon, Tae-Sun Lim, Heon Kim, Kyoung-Hoon Kim, Jung-Min Lee, Kyung-Lim Paik, Sang-Doo Ahn
  • Publication number: 20080319157
    Abstract: Disclosed is a method for producing a norbornene monomer composition, a norbornene polymer produced using the norbornene monomer composition, an optical film including the norbornene polymer, and a method for producing the norbornene polymer. The method includes reacting a reaction solution that contains cyclopentadiene, dicyclopentadiene, or a mixture of cyclopentadiene and dicyclopentadiene, an acetate compound, and a solvent so that a content of an exo isomer is 50 mol % or more. Variables such as a reaction temperature, a reaction time, a molar ratio between reactants, and addition of a solvent are controlled so that the exo isomer is contained in content of 50 mol % or more. Accordingly, it is possible to industrially produce an acetate norbornene addition polymer by using the acetate norbornene monomer composition containing the exo isomer in content of 50 mol % or more.
    Type: Application
    Filed: April 4, 2008
    Publication date: December 25, 2008
    Applicant: LG CHEM, LTD.
    Inventors: Sung-Ho CHUN, Won-Kook KIM, Sung-Cheol YOON, Tae-Sun LIM, Heon KIM, Kyoung-Hoon KIM, Jung-Min LEE, Kyung-Lim PAIK, Sang-Doo AHN
  • Patent number: 7442752
    Abstract: The present invention relates to a norbornene based addition polymer, and more particularly to an addition polymer of norbornene based monomers containing an ester group. The present invention provides a norbornene-ester based addition polymer having a molecular weight (Mn) larger than 20,000 and comprising a norbornene-ester based monomer comprising more than 50 mol % of exo norbornene-ester monomer as a repeating unit, a method for preparing the same, and an optically anisotropic film comprising the same. The norbornene-ester based addition polymer of the present invention is transparent, has a low dielectric constant, has good thermal stability and strength, leaves no unwanted materials when attached to metals or other polymers, and has good adhesivity, so that it can be used for optical films, retardation films, plastic substrate materials, transparent polymers such as POF or PCB, insulating materials, or insulating electronic devices such as PCB or insulating materials.
    Type: Grant
    Filed: July 7, 2003
    Date of Patent: October 28, 2008
    Assignee: LG Chem, Ltd.
    Inventors: Sung-Ho Chun, Won-Kook Kim, Sung-Cheol Yoon, Tae-Sun Lim, Heon Kim, Kyoung-Hoon Kim, Jung-Min Lee, Kyung-Lim Paik, Sang-Doo Ahn
  • Publication number: 20050010006
    Abstract: The present invention relates to a norbornene based addition polymer, and more particularly to an addition polymer of norbornene based monomers containing an ester group. The present invention provides a norbornene-ester based addition polymer having a molecular weight (Mn) larger than 20,000 and comprising a norbornene-ester based monomer comprising more than 50 mol % of exo norbornene-ester monomer as a repeating unit, a method for preparing the same, and an optically anisotropic film comprising the same. The norbornene-ester based addition polymer of the present invention is transparent, has a low dielectric constant, has good thermal stability and strength, leaves no unwanted materials when attached to metals or other polymers, and has good adhesivity, so that it can be used for optical films, retardation films, plastic substrate materials, transparent polymers such as POF or PCB, insulating materials, or insulating electronic devices such as PCB or insulating materials.
    Type: Application
    Filed: July 7, 2003
    Publication date: January 13, 2005
    Inventors: Sung-Ho Chun, Won-Kook Kim, Sung-Cheol Yoon, Tae-Sun Lim, Heon Kim, Kyung-Hoon Kim, Jung-Min Lee, Kyung-Lim Paik, Sang-Doo Ahn