Patents by Inventor Jae Kyoung Roh

Jae Kyoung Roh 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: 8313881
    Abstract: A toner for an electrophotographic image forming process or an electrostatic printing process, and a polyester resin for the toner are disclosed. The polyester resin comprises: acid components including 70 to 96 mol % of aromatic dibasic acid component, 3 to 20 mol % of cycloaliphatic dibasic acid component, and 1 to 10 mol % of trivalent or higher acid component; alcohol components including 10 to 50 mol % of cycloaliphatic diol component, 2 to 20 mol % of trihydric or higher alcohol component, and 30 to 88 mol % of aliphatic diol component; and a heat stabilizer.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: November 20, 2012
    Assignee: SK Chemicals Co., Ltd.
    Inventors: Young-Man Yoo, Jae-Kyoung Roh, Kye-Yune Lee, Tae-Woong Lee
  • Patent number: 8133650
    Abstract: A polyester resin which includes acid components having aromatic dibasic acid component and trivalent or higher acid component; alcohol components including aliphatic, aromatic or cycloaliphatic diol component, and trihydric or higher alcohol component; polyolefin polyol having 1,800 to 2,500 number average molecular weight and hydroxyl value of 40 to 55 KOHmg/g; and wax having melting point of 80 to 110, wherein the amount of the polyolefin polyol is 0.1 to 2 weight % and the amount of the wax is 0.5 to 15 weight % with respect to the total polyester resin. Also disclosed is a method for preparing polyester resin by (a) carrying out an esterification reaction or an ester exchange reaction with the acid components, the alcohol components, and the polyolefin polyol; and (b) carrying out a polycondensation reaction for reaction product of the esterification or ester exchange reaction in the presence of the wax.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: March 13, 2012
    Assignee: SK Chemicals Co., Ltd.
    Inventors: Young-Man Yoo, Jae-Kyoung Roh, Kye-Yune Lee, Tae-Woong Lee
  • Publication number: 20100261867
    Abstract: A toner for an electrophotographic image forming process or an electrostatic printing process, and a polyester resin for the toner are disclosed. The polyester resin comprises: acid components including aromatic dibasic acid component and trivalent or higher acid component; alcohol components including aliphatic, aromatic or cycloaliphatic diol component, and trihydric or higher alcohol component; poly olefin polyol having number average molecular weight of 1,800 to 2,500 and hydroxyl value of 40 to 55 KOHmg/g; and wax having melting point of 80 to 110° C., wherein the amount of the poly olefin polyol is 0.1 to 2 weight % and the amount of the wax is 0.5 to 15 weight % with respect to the total polyester resin.
    Type: Application
    Filed: July 10, 2008
    Publication date: October 14, 2010
    Inventors: Young-Man Yoo, Jae-Kyoung Roh, Kye-Yune Lee, Tae-Woong Lee
  • Publication number: 20100239970
    Abstract: A toner for an electrophotographic image forming process or an electrostatic printing process, and a polyester resin for the toner are disclosed. The polyester resin comprises: acid components including 70 to 96 mol % of aromatic dibasic acid component, 3 to 20 mol % of cycloaliphatic dibasic acid component, and 1 to 10 mol % of trivalent or higher acid component; alcohol components including 10 to 50 mol % of cycloaliphatic diol component, 2 to 20 mol % of trihydric or higher alcohol component, and 30 to 88 mol % of aliphatic diol component; and a heat stabilizer.
    Type: Application
    Filed: July 10, 2008
    Publication date: September 23, 2010
    Inventors: Young-Man Yoo, Jae-Kyoung Roh, Kye-Yune Lee, Tae-Woong Lee
  • Publication number: 20080113289
    Abstract: A polyester resin for toner, which has superior fixing property, storage stability, and image density in an electrophotographic image forming process or an electrostatic printing process, and a toner including the same are disclosed. The polyester resin for toner is produced by carrying out esterification reaction and polycondensation reaction of reactant comprising aromatic dibasic acid of 80 to 100 mol % with respect to the total dibasic acid, trivalent or higher acid of 0.5 to 30 mol % with respect to the total dibasic acid, aromatic diol of equal to or less than 90 mol % with respect to the total dibasic acid, and aliphatic diol of 10 to 80 mol % with respect to the total dibasic acid, in the presence of a polycondensation catalyst selected from the group consisting of TiO2/SiO2 coprecipitates, TiO2/ZrO2 coprecipitates and the mixture thereof.
    Type: Application
    Filed: December 21, 2005
    Publication date: May 15, 2008
    Inventors: Jae-Kyoung Roh, Young-Man Yoo, Kyoung-Ha Lee, Kye-Yune Lee, Tae-Woong Lee
  • Patent number: 6756171
    Abstract: The present invention relates to polyester resin for toner used for developing an electrostatic latent image such as a statically charged image in the electrostatic printing process and discloses polyester resin for toner comprising aromatic dicarboxylic acid, trivalent or higher carboxylic acid, aliphatic diol, bisphenol A derivative aromatic diol, and trihydric or higher alcohol, characterized in that the amount of the aromatic diol of bisphenol A derivative having the mole number of ethylene oxide and/or propylene oxide of 2mole is equal to or more than 85weight % in the entire aromatic diol of bisphenol A derivative, and the amount of the aromatic diol of bisphenol A derivative having the mole number of ethylene oxide or propylene oxide of 1mole is less than 0.2weight % in the entire aromatic diol of bisphenol A derivative.
    Type: Grant
    Filed: January 15, 2002
    Date of Patent: June 29, 2004
    Assignee: SK Chemicals Co., Ltd.
    Inventors: Jae Kyoung Roh, Kye Yune Lee, Tae Woong Lee