Patents by Inventor Yeon Tak Choi

Yeon Tak 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).

  • Patent number: 10227442
    Abstract: The present invention provides an optical polymerizable composition, an optical composition, a large-area window, a polyisocyanate composition, and eyeglass lens and producing method thereof. The optical polymerizable composition is composed of a polythiol compound and a polyisocyanate compound, and a urethane-based optical lens obtained by reacting the compounds has a low specific gravity and thus is lightweight, and has excellent heat resistance, and particularly, problems of degradation in impact resistance which appear after hard-multi coating are solved. The lens produced using the composition has various excellent optical characteristics including workability such as formability and dyeability, transparency and the like.
    Type: Grant
    Filed: July 14, 2015
    Date of Patent: March 12, 2019
    Assignee: KS LABORATORIES CO., LTD.
    Inventors: Keun Sik Kim, Yeon Tak Choi
  • Publication number: 20180201718
    Abstract: The present invention relates to an optical composition for blocking near-infrared rays, comprising a mixture of a polyurethane-based thermosetting resin composition and a near-infrared absorbent, wherein the optical composition for blocking near-infrared rays comprises (1) at least one of polyisocyanate compounds in a liquid phase (I); (2) at least one of polyol or polythiol compounds in a liquid phase (II); and (3) a near-infrared absorbent having a high near-infrared absorbing ability of less than 5% in the range of 800-1000 nm, and to a method for manufacturing near-infrared blocking spectacle lens using the same. The spectacle lens obtained from the optical composition of the present invention can effectively prevent damage to the retina by effectively blocking near-infrared rays.
    Type: Application
    Filed: July 12, 2016
    Publication date: July 19, 2018
    Inventors: Keun Sik KIM, Yeon Tak CHOI
  • Publication number: 20170198083
    Abstract: The present invention provides an optical polymerizable composition, an optical composition, a large-area window, a polyisocyanate composition, and eyeglass lens and producing method thereof. The optical polymerizable composition is composed of a polythiol compound and a polyisocyanate compound, and a urethane-based optical lens obtained by reacting the compounds has a low specific gravity and thus is lightweight, and has excellent heat resistance, and particularly, problems of degradation in impact resistance which appear after hard-multi coating are solved. The lens produced using the composition has various excellent optical characteristics including workability such as formability and dyeability, transparency and the like.
    Type: Application
    Filed: July 14, 2015
    Publication date: July 13, 2017
    Inventors: Keun Sik KIM, Yeon Tak CHOI
  • Patent number: 9332762
    Abstract: The present invention relates to a method for preparing amicarbazone by using amino-triazolinone, which is an intermediate compound, and relates to a method for preparing amicarbazone, comprising the steps of: obtaining hydrazine carboxylic acid represented by 5 chemical formula (V) by reacting acylhydrazide represented by chemical formula (II) and a carbamating agent represented by chemical formula (III) or (IV); reacting the obtained hydrazine carboxylic acid represented by chemical formula (V) and hydrazine hydrate in the presence of a base catalyst; and reacting the obtained compound represented by chemical formula (I) 10 and an alkyl isocyanate represented by chemical formula (IV) in the presence of a base catalyst. Amino-triazolinone and amicarbazone would be stably produced by the present invention without safety gear and safety facilities for the leakage of phosgene, which has been conventionally used as a reactant.
    Type: Grant
    Filed: January 22, 2014
    Date of Patent: May 10, 2016
    Assignee: KS LABORATORIES CO., LTD.
    Inventors: Keun Sik Kim, Yeon Tak Choi
  • Publication number: 20150336906
    Abstract: The present invention relates to a method for preparing amicarbazone by using amino-triazolinone, which is an intermediate compound, and relates to a method for preparing amicarbazone, comprising the steps of: obtaining hydrazine carboxylic acid represented by 5 chemical formula (V) by reacting acylhydrazide represented by chemical formula (II) and a carbamating agent represented by chemical formula (III) or (IV); reacting the obtained hydrazine carboxylic acid represented by chemical formula (V) and hydrazine hydrate in the presence of a base catalyst; and reacting the obtained compound represented by chemical formula (I) 10 and an alkyl isocyanate represented by chemical formula (IV) in the presence of a base catalyst. Amino-triazolinone and amicarbazone would be stably produced by the present invention without safety gear and safety facilities for the leakage of phosgene, which has been conventionally used as a reactant.
    Type: Application
    Filed: January 22, 2014
    Publication date: November 26, 2015
    Inventors: Keun Sik KIM, Yeon Tak CHOI
  • Patent number: 8957221
    Abstract: The present invention relates to a method for preparing an amino-triazolinone which can be used as a raw material for amicarbazone and has chemical formula (I). The method for preparing the amino-triazolinone includes the steps of: reacting an acyl hydrazide of chemical formula (II) with a carbamating agent of chemical formula (III) or (IV) so as to obtain a hydrazine carboxylic acid of chemical formula (V); and reacting the thus-obtained hydrazine carboxylic acid of chemical formula (V) with a hydrazine hydrate under the presence of a base catalyst. According to the present invention, the amino-triazolinone may be stably prepared without using safety equipment or safety facilities for a possible leakage of phosgene, which has been used as a conventional reactant.
    Type: Grant
    Filed: July 27, 2012
    Date of Patent: February 17, 2015
    Assignee: KS Laboratories Co., Ltd.
    Inventors: Keun Sik Kim, Yeon Tak Choi
  • Publication number: 20140163239
    Abstract: The present invention relates to a method for preparing an amino-triazolinone which can be used as a raw material for amicarbazone and has chemical formula (I). The method for preparing the amino-triazolinone includes the steps of: reacting an acyl hydrazide of chemical formula (II) with a carbamating agent of chemical formula (III) or (IV) so as to obtain a hydrazine carboxylic acid of chemical formula (V); and reacting the thus-obtained hydrazine carboxylic acid of chemical formula (V) with a hydrazine hydrate under the presence of a base catalyst. According to the present invention, the amino-triazolinone may be stably prepared without using safety equipment or safety facilities for a possible leakage of phosgene, which has been used as a conventional reactant.
    Type: Application
    Filed: July 27, 2012
    Publication date: June 12, 2014
    Applicant: KS LABORATORIES CO., LTD.
    Inventors: Keun Sik Kim, Yeon Tak Choi