The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 02, 2008
Filed:
Feb. 12, 2004
Kazushige Kojima, Aichi, JP;
Kojiro Tachi, Aichi, JP;
Hisayoshi Fujikawa, Aichi, JP;
Koji Noda, Aichi, JP;
Masahiko Ishii, Aichi, JP;
Yasunori Taga, Aichi, JP;
Makoto Satsuki, Okayama, JP;
Makoto Fujiwara, Okayama, JP;
Natsuko Ishida, Okayama, JP;
Sadaharu Suga, Okayama, JP;
Kazushige Kojima, Aichi, JP;
Kojiro Tachi, Aichi, JP;
Hisayoshi Fujikawa, Aichi, JP;
Koji Noda, Aichi, JP;
Masahiko Ishii, Aichi, JP;
Yasunori Taga, Aichi, JP;
Makoto Satsuki, Okayama, JP;
Makoto Fujiwara, Okayama, JP;
Natsuko Ishida, Okayama, JP;
Sadaharu Suga, Okayama, JP;
Kabushiki Kaisha Hayashibara Seibutsu Kagaku Kenkyujo, Okayama, JP;
Abstract
This invention has an objective to improve durability at elevated temperature in organic electroluminescent devices using coumarin derivatives as dopant in a luminescent layer. This invention attains the above objective by providing in the organic electroluminescent devices formed by laminating an anode, a hole injection layer, a hole transportation layer, a luminescent layer, an electron transportation layer and a cathode in this order, the luminescent layer which comprises as dopant the green light-emitting coumarin derivative and hole- and electron-transporting substances as host; said coumarin derivative consisting of a plurality of coumarin groups bound to an aromatic ring, heterocycle, or any combination thereof, and exhibiting a glass transition point of 150° C. or higher or a melting point of 297° C. or higher.