Patents by Inventor Han Jin Kwag

Han Jin Kwag 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: 8835687
    Abstract: Provided is a method for preparing 4,4?-dinitrodiphenylamine (4,4?-DNDPA) in high yield via the NASH reaction using a mixture of a bis-quaternary ammonium base and a base catalyst for the reaction of urea with nitrobenzene, and a method of preparing 4,4?-bis(alkylamino)diphenylamine (4,4?BAADA) in high yield and purity by hydrogenating the resulting 4,4?-DNDPA with a ketone in the presence of hydrogen and hydrogenation catalyst. The catalyst complex used in the present invention allows easy recovery, provides superior alkaline stability and is capable of reducing production cost.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: September 16, 2014
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Jin-Eok Kim, Seoung-IL Kim, Han Jin Kwag, Sang hee Park
  • Patent number: 8759587
    Abstract: Provided is a method of preparing 4,4?-dinitrodiphenylamine (4,4?-DNDPA) in high yield by reacting 4-nitroaniline with excess nitrobenzene via the NASH reaction, and a method of preparing 4,4?-bis(alkylamino)diphenylamine (4,4?BAADA) in high yield and purity by hydrogenating the resulting 4,4?-DNDPA with a ketone compound in the presence of hydrogen and hydrogenation catalyst. The disclosed process is simple, allows selective preparation of 4,4?-DNDPA without byproducts, and thus allows preparation of 4,4?-BAADA in high yield without a complicated purification procedure.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: June 24, 2014
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Jin-Eok Kim, Seoung-Il Kim, Han Jin Kwag, Sang hee Park
  • Patent number: 8283477
    Abstract: The present invention relates to a method of preparing N-substituted maleimide in high purity and high yield, wherein, unlike a conventional method of preparing N-substituted maleimide after preparing N-substituted maleamic acid, an organic solvent, an acid catalyst, a dehydration co-catalyst and a stabilizer are added into a reactor without separately preparing N-substituted maleamic acid, and then a primary amine is added into the reactor to form an amine salt, maleic anhydride is added into the reactor, and the resulting mixture is subjected to a dehydration-cyclization reaction, wherein water produced during the reaction is azeotropically distilled with the organic solvent so as to effectively suppress formation of a maleimide polymer.
    Type: Grant
    Filed: June 24, 2009
    Date of Patent: October 9, 2012
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Jin-Eok Kim, Seung-il Kim, Han-Jin Kwag
  • Publication number: 20120197044
    Abstract: The present invention relates to a production method for 4,4?-bis(alkylamino)diphenylamine, and more specifically relates to a method in which 4,4?-dinitrodiphenylamine (4,4?-DNDPA) is produced by reacting urea with nitrobenzene in the presence of a polar organic solvent and a base catalyst, and then the 4,4?-bis(alkylamino)diphenylamine (4,4?-BAADA) is produced by subjecting the 4,4?-DNDPA and a ketone to hydrogenation in the presence of a hydrogenation catalyst.
    Type: Application
    Filed: September 30, 2010
    Publication date: August 2, 2012
    Applicant: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Jin Eok Kim, Seung Il Kim, Jung Hee Jang, Han Jin Kwag
  • Publication number: 20120157713
    Abstract: Provided is a method for preparing 4,4?-dinitrodiphenylamine (4,4?-DNDPA) in high yield via the NASH reaction using a mixture of a bis-quaternary ammonium base and a base catalyst for the reaction of urea with nitrobenzene, and a method of preparing 4,4?-bis(alkylamino)diphenylamine (4,4?BAADA) in high yield and purity by hydrogenating the resulting 4,4?-DNDPA with a ketone in the presence of hydrogen and hydrogenation catalyst. The catalyst complex used in the present invention allows easy recovery, provides superior alkaline stability and is capable of reducing production cost.
    Type: Application
    Filed: June 17, 2011
    Publication date: June 21, 2012
    Applicant: KOREA KUMHO PETROCHEMICAL CO., LTD.
    Inventors: Jin-Eok Kim, Seoung-IL Kim, Han Jin Kwag, Sang hee Park
  • Publication number: 20120157714
    Abstract: Provided is a method of preparing 4,4?-dinitrodiphenylamine (4,4?-DNDPA) in high yield by reacting 4-nitroaniline with excess nitrobenzene via the NASH reaction, and a method of preparing 4,4?-bis(alkylamino)diphenylamine (4,4?BAADA) in high yield and purity by hydrogenating the resulting 4,4?-DNDPA with a ketone compound in the presence of hydrogen and hydrogenation catalyst. The disclosed process is simple, allows selective preparation of 4,4?-DNDPA without byproducts, and thus allows preparation of 4,4?-BAADA in high yield without a complicated purification procedure.
    Type: Application
    Filed: June 17, 2011
    Publication date: June 21, 2012
    Applicant: KOREA KUMHO PETROCHEMICAL CO., LTD.
    Inventors: Jin-Eok Kim, Seoung-IL Kim, Han Jin Kwag, Sang hee Park
  • Publication number: 20110124882
    Abstract: The present invention relates to a method of preparing N-substituted maleimide in high purity and high yield, wherein, unlike a conventional method of preparing N-substituted maleimide after preparing N-substituted maleamic acid, an organic solvent, an acid catalyst, a dehydration co-catalyst and a stabilizer are added into a reactor without separately preparing N-substituted maleamic acid, and then a primary amine is added into the reactor to form an amine salt, maleic anhydride is added into the reactor, and the resulting mixture is subjected to a dehydration-cyclization reaction, wherein water produced during the reaction is azeotropically distilled with the organic solvent so as to effectively suppress formation of a maleimide polymer.
    Type: Application
    Filed: June 24, 2009
    Publication date: May 26, 2011
    Applicant: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Jin-Eok Kim, Seung-il Kim, Han-Jin Kwag
  • Patent number: 7468417
    Abstract: The present invention relates to a method of preparing a copolymer having controlled gel content by polymerizing cyclic olefin compound by ROMP (Ring Opening Metathesis Polymerization), and more precisely, a method of preparing cyclic olefin copolymer with high yield, in which a complex prepared by mixing a W salt compound and an organoaluminum halide compound is used as a catalyst in the presence or absence of a molecular weight regulator, and a method of controlling gel formation by regulating the composition of cyclic olefin monomer composing a copolymer as shown in the following Empirical Formula 1 without using a reaction speed regulator or gel formation inhibitor. (Empirical Formula 1) Norbornene=30˜70 weight % Cyclic olefin compound=70˜30 weight % At this time, the cyclic olefin compound presented in the above Empirical Formula 1 is one or more compounds selected from a group consisting of dicyclopentadiene and compounds represented by the following Formula 1.
    Type: Grant
    Filed: August 24, 2006
    Date of Patent: December 23, 2008
    Assignee: Korea Kumho Petrochemical Co., Ltd.
    Inventors: Youngchan Jang, Hyun-Kyung Sung, Han Jin Kwag