Patents by Inventor Takahiro Kai

Takahiro Kai 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: 8227798
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution. Also disclosed is a compound useful for the fabrication of said organic EL device. The organic electroluminescent device comprises organic layers including a light-emitting layer disposed between an anode and a cathode which are piled one upon another on a substrate and said organic layers comprise a compound represented by general formula (1). A light-emitting layer containing a phosphorescent dopant is suitable for an organic layer comprising a compound represented by general formula (1).
    Type: Grant
    Filed: March 24, 2008
    Date of Patent: July 24, 2012
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Takahiro Kai, Toshihiro Yamamoto, Masanori Hotta, Junya Ogawa
  • Publication number: 20120007070
    Abstract: Provided is an organic electroluminescent device (organic EL device), which has improved luminous efficiency, shows sufficiently ensured driving stability, and has a simple construction. The organic electroluminescent device includes an anode, a cathode, and organic layers including a hole-transporting layer and a light-emitting layer, the organic layers being interposed between the anode and the cathode, in which the light-emitting layer contains a phosphorescent light-emitting material and the hole-transporting layer and the light-emitting layer have an electron- and/or exciton-blocking layer therebetween, the electron- and/or exciton-blocking layer being adjacent to the light-emitting layer and containing an indolocarbazole compound represented by the general formula (2). In the formula, a ring B represents a heterocycle represented by the formula (1c) to be fused with adjacent rings, Z represents an n-valent aromatic hydrocarbon group or an aromatic heterocyclic group, and n represents 1 or 2.
    Type: Application
    Filed: March 25, 2010
    Publication date: January 12, 2012
    Inventors: Takahiro Kai, Toshihiro Yamamoto, Masaki Komori, Kazuaki Yoshimura, Taishi Tsuji, Yasuhiro Takahashi
  • Publication number: 20120001165
    Abstract: Provided is an organic electroluminescent device (organic EL device), which has improved luminous efficiency, has sufficient driving stability, and has a simple construction. The organic EL device of the present invention is an organic electroluminescent device, including a light-emitting layer and a hole-transporting layer between an anode and a cathode laminated on a substrate, in which the light-emitting layer contains a phosphorescent light-emitting dopant and an indolocarbazole compound that serves as a host material, or alternatively, the hole-transporting layer contains an indolocarbazole compound. The indolocarbazole compound is represented by the following formula (1). In the formula: A1's each represent an aromatic hydrocarbon group or an aromatic heterocyclic group, provided that at least one of A1's has a fused ring structure; and R1's each represent a hydrogen atom, an alkyl group, an alkoxy group, or an acyl group.
    Type: Application
    Filed: March 25, 2010
    Publication date: January 5, 2012
    Inventors: Masaki Komori, Takahiro Kai, Toshihiro Yamamoto
  • Publication number: 20110315975
    Abstract: Provided is an organic electroluminescent device (organic EL device), in which the luminous efficiency of the device is improved, driving stability is sufficiently ensured, and the construction of the device is simple. This organic EL device is an organic electroluminescent device, including a light-emitting layer between an anode and a cathode laminated on a substrate, in which the light-emitting layer contains a phosphorescent light-emitting dopant and an indolocarbazole compound as a host material. Examples of the indolocarbazole compound include a compound represented by the following formula (1).
    Type: Application
    Filed: March 24, 2010
    Publication date: December 29, 2011
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto, Megumi Matsumoto
  • Publication number: 20110284828
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of high driving stability, and of a simple structure. The organic EL device is constituted of an anode, organic layers containing a phosphorescent light-emitting layer, and a cathode piled one upon another on a substrate and a phosphine oxide derivative represented by general formula (1) is contained in a phosphorescent light-emitting layer, an electron-transporting layer, a hole-blocking layer, or an exciton-blocking layer. In general formula (1), L1 is a direct bond or an aromatic group with a valence of 1-3 and Ar1 is an aromatic group. The two Ar1 groups linked to the same nitrogen atom may form a nitrogen heterocycle and may further form a fused ring together with the said nitrogen heterocycle.
    Type: Application
    Filed: February 25, 2010
    Publication date: November 24, 2011
    Inventors: Takahiro Kai, Hideki Tanaka, Mitsuru Suda, Toshihiro Yamamoto, Megumi Matsumoto
  • Patent number: 8062769
    Abstract: Provided is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, fully secured of driving stability, and simply constructed. The EL device has a light-emitting layer disposed between an anode and a cathode stacked one upon another on a substrate and the light-emitting layer comprises a phosphorescent dopant and an indolocarbazole derivative as a host material. Examples of the indolocarbazole compounds include a compound represented by the following formula (2) or (3), wherein X is N or CH, at least one of Xs is N, and Ar1 to Ar3 each is a substituted or unsubstituted aromatic group.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: November 22, 2011
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto
  • Publication number: 20110272680
    Abstract: Disclosed is a useful organic EL device which comprises a phosphorescent light-emitting layer and is endowed with improved luminous efficiency and high driving stability. Also disclosed is a hole-transporting material suitable for use in the phosphorescent light-emitting device. The hole-transporting material is a triptycene derivative which has substituents at the 9- and 10-positions and is substituted with an aromatic group containing at least one diarylamino group (—ArNAr2). The organic EL device contains the triptycene derivative in at least one organic layer selected from the group of a phosphorescent light-emitting layer, a hole-transporting layer, an electron-blocking layer, and an exciton-blocking layer. The diarylamino group (—NAr2) may be fused to form an aromatic heterocyclic group such as a carbazolyl group.
    Type: Application
    Filed: January 15, 2010
    Publication date: November 10, 2011
    Applicant: NIPPON STEEL CHEMICAL CO., LTD.
    Inventors: Mitsuru Suda, Takahiro Kai, Toshihiro Yamamoto
  • Publication number: 20110253991
    Abstract: [Problem to be Solved] To provide an organic electroluminescence device with heat resistance capable of being driven by a low voltage. [Solution] An organic electroluminescence device includes a pair of anode and cathode opposed to each other; and a plurality of organic semiconductor layers layered or disposed between the anode and the cathode, the organic semiconductor layers including a light-emitting layer. At least one of the organic semiconductor layers contains a bulky organic semiconductor compound having an aromatic multi-membered ring structure and at least three aromatic substituents bonded thereto. Each of the aromatic substituents is arranged in a manner that a dihedral angle between a ring plane of the aromatic multi-membered ring structure and the ring plane of the aromatic substituent is within 70 to 90° determined by a semiempirical molecular orbital calculation method.
    Type: Application
    Filed: November 25, 2009
    Publication date: October 20, 2011
    Applicants: NIPPON STEEL CHEMICAL CO., LTD., PIONEER CORPORATION
    Inventors: Takahito Oyamada, Taishi Tsuji, Takahiro Kai, Junya Ogawa, Mitsuru Suda
  • Patent number: 8013330
    Abstract: Disclosed are a compound for an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution and an organic EL device using said compound. The compound for an organic EL device has two indolocarbazole skeletons each of which is bonded to an aromatic group or two skeletons similar thereto. The organic EL device comprises a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and said light-emitting layer comprises a phosphorescent dopant and the aforementioned compound for an organic EL device as a host material.
    Type: Grant
    Filed: May 23, 2008
    Date of Patent: September 6, 2011
    Assignee: Nippon Steel Chemical Co., Ltd
    Inventors: Masaki Komori, Toshihiro Yamamoto, Takahiro Kai, Katsuhide Noguchi, Hiroshi Miyazaki
  • Patent number: 8012606
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and simple in structure and also disclosed is a heterocyclic compound useful for the said device. Specifically, the heterocyclic compound is represented by the following general formula (I) and the organic EL device comprises an organic layer containing the said heterocyclic compound. In general formula (I), X1 and X2 respectively denote O, S, or N—R, R denotes a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Ar1, Ar2, Ar3, and Ar4 respectively denote a substituted or unsubstituted aryl group, Ar1, Ar2, and the nitrogen atom bonded thereto or Ar3, Ar4, and the nitrogen atom bonded thereto may form a nitrogen-containing hetero ring, and m and n respectively denote an integer of 1 or 2.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: September 6, 2011
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Takahiro Kai, Toshihiro Yamamoto, Masaki Komori, Masanori Hotta, Yuichi Sawada
  • Patent number: 8008657
    Abstract: Disclosed are an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution and a compound useful for the fabrication of said organic EL device. The compound for the organic EL device has an indolocarbazole structure or a structure similar thereto in the molecule wherein an aromatic group is bonded to the nitrogen atom in the indolocarbazole. The organic EL device has a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and said light-emitting layer comprises a phosphorescent dopant and the aforementioned compound for an organic electroluminescent device as a host material.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: August 30, 2011
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto, Katsuhide Noguchi, Hiroshi Miyazaki
  • Patent number: 7993760
    Abstract: Disclosed are an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and simple in constitution and a compound for use therein. The organic electroluminescent device comprises a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and the light-emitting layer contains a phosphorescent dopant and a compound for use in an organic electroluminescent device having two or more indolocarbazole skeletons as a host material. An example of the compound having indolocarbazole skeletons for use in the device is expressed by the following formula.
    Type: Grant
    Filed: November 22, 2006
    Date of Patent: August 9, 2011
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Masaki Komori, Toshihiro Yamamoto, Takahiro Kai, Masanori Hotta
  • Publication number: 20110062429
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) that is improved in the luminous efficiency, fully secured of the driving stability, and of a simple structure and also disclosed is a compound for organic EL device useful for the said device. The compound for organic EL device is, for example, an indolocarbazole derivative represented by the following general formula (3). The organic EL device comprises a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and the said light-emitting layer comprises a phosphorescent dopant and the aforementioned indolocarbazole derivative as a host material. In general formula (3), L is an aromatic heterocyclic group of a fused-ring structure with a valence of (n+1), Ar1 to Ar3 each is an alkyl group, an aralkyl group, or a substituted or unsubstituted aromatic hydrocarbon or aromatic heterocyclic group, and n is an integer of 0-5.
    Type: Application
    Filed: April 30, 2009
    Publication date: March 17, 2011
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto
  • Publication number: 20110062862
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) that is improved in the luminous efficiency, fully secured of the driving stability, and of a simple structure. The organic EL device comprises a light-emitting layer between an anode and a cathode piled one upon another on a substrate and the said light-emitting layer comprises (A) a phosphorescent dopant whose emission peak wavelength is longer than 600 nm and (B) a host material. The host material contains at least two kinds of compounds selected from two or more kinds of derivatives included in (b1) N-substituted indolocarbazole derivatives, (b2) derivatives of 8-hydroxyquinoline aluminum complex, and (b3) bisindolocarbazole derivatives.
    Type: Application
    Filed: April 30, 2009
    Publication date: March 17, 2011
    Inventors: Toshihiro Yamamoto, Takahiro Kai, Masaki Komori, Taishi Tsuji, Yasuhiro Takahashi, Toshinao Yuki, Yusuke Nakajima, Tomoaki Hoshi, Jiro Asaka
  • Publication number: 20110057184
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) that is improved in the luminous efficiency, fully secured of the driving stability, and of a simple structure and disclosed also is a compound useful therefor. The organic EL device comprises a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and the said light-emitting layer comprises a phosphorescent dopant and an indolocarbazole derivative as a host material. The indolocarbazole derivative is represented by the following formula (3) wherein Ar is an aromatic group and L is a direct bond or an aromatic group.
    Type: Application
    Filed: April 30, 2009
    Publication date: March 10, 2011
    Applicant: NIPPON STEEL CHEMICAL CO., LTD.
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto
  • Publication number: 20110024735
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, fully secured of driving stability, and of simple structure. The organic EL device comprises a light-emitting layer between an anode and a cathode piled one upon another on a substrate and the light-emitting layer comprises a phosphorescent dopant and a compound containing carbazolyl groups at both ends represented by the following formula (1) as a host material. In formula (1), X is independently CH optionally containing a substituent or N and L is a direct bond, an ethylene group, or an acetylene group.
    Type: Application
    Filed: February 2, 2009
    Publication date: February 3, 2011
    Inventors: Yuichi Sawada, Takahiro Kai, Masaki Komori, Toshihiro Yamamoto
  • Publication number: 20100244013
    Abstract: Disclosed is an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution. Also disclosed is a compound useful for the fabrication of said organic electroluminescent device. This compound for organic electroluminescent device is a bipyrimidyl compound which has a basic skeleton of 2,2?-bipyrimidyl and is substituted by an aromatic hydrocarbon group, an aromatic heterocyclic group, or a substituted amino group. The aforementioned organic electroluminescent device has a light-emitting layer between an anode and a cathode which are piled one upon another on a substrate and the light-emitting layer contains a phosphorescent dopant and the aforementioned bipyrimidyl compound as a host material.
    Type: Application
    Filed: December 24, 2008
    Publication date: September 30, 2010
    Inventors: Takahiro Kai, Junya Ogawa, Toshihiro Yamamoto
  • Publication number: 20100187977
    Abstract: Provided is an organic electroluminescent device (organic EL device) that is improved in luminous efficiency, fully secured of driving stability, and simply constructed. The EL device has a light-emitting layer disposed between an anode and a cathode stacked one upon another on a substrate and the light-emitting layer comprises a phosphorescent dopant and an indolocarbazole derivative as a host material. Examples of the indolocarbazole compounds include a compound represented by the following formula (2) or (3), wherein X is N or CH, at least one of Xs is N, and Ar1 to Ar3 each is a substituted or unsubstituted aromatic group.
    Type: Application
    Filed: November 8, 2007
    Publication date: July 29, 2010
    Applicant: NIPPON STEEL CHEMICAL CO., LTD.
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto
  • Publication number: 20100148162
    Abstract: Disclosed are a compound for an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution and an organic EL device using said compound. The compound for an organic EL device has two indolocarbazole skeletons each of which is bonded to an aromatic group or two skeletons similar thereto. The organic EL device comprises a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and said light-emitting layer comprises a phosphorescent dopant and the aforementioned compound for an organic EL device as a host material.
    Type: Application
    Filed: May 23, 2008
    Publication date: June 17, 2010
    Inventors: Masaki Komori, Toshihiro Yamamoto, Takahiro Kai, Katsuhide Noguchi, Hiroshi Miyazaki
  • Publication number: 20100148161
    Abstract: Disclosed are an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of driving stability, and of simple constitution and a compound useful for the fabrication of said organic EL device. The compound for the organic EL device has an indolocarbazole structure or a structure similar thereto in the molecule wherein an aromatic group is bonded to the nitrogen atom in the indolocarbazole. The organic EL device has a light-emitting layer disposed between an anode and a cathode piled one upon another on a substrate and said light-emitting layer comprises a phosphorescent dopant and the aforementioned compound for an organic electroluminescent device as a host material.
    Type: Application
    Filed: May 28, 2008
    Publication date: June 17, 2010
    Inventors: Takahiro Kai, Masaki Komori, Toshihiro Yamamoto, Katsuhide Noguchi, Hiroshi Miyazaki