Patents by Inventor Yoshiaki Tsubata

Yoshiaki Tsubata 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).

  • Publication number: 20020122899
    Abstract: A polymeric fluorescent substance exhibiting fluorescence in the solid state, having a polystyrene reduced number-average molecular weight of 1'103 to 1×108, and comprising one or more repeating units of formula (1) and one or more repeating units of formula (8),
    Type: Application
    Filed: November 29, 2001
    Publication date: September 5, 2002
    Applicant: SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Shuji Doi, Yoshiaki Tsubata, Takahiro Ueoka, Shigeru Sasaki, Takanobu Noguchi
  • Patent number: 6444334
    Abstract: A polymeric fluorescent substance exhibiting fluorescence in solid state and having a polystyrene-reduced number-average molecular weight of 103 to 108 wherein the polymeric fluorescent substance contains one or more of segments represented by the following formula (1) and one or more of repeating units represented by the following formula (2): The polymeric fluorescent substance exhibits particularly strong fluorescence, and a high performance polymer LED which can be driven at low voltage and high efficiency is obtained.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: September 3, 2002
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Shuji Doi, Yoshiaki Tsubata, Takahiro Ueoka
  • Publication number: 20020058157
    Abstract: A polymeric fluorescent substance exhibiting fluorescence in solid state and having a polystyrene-reduced number-average molecular weight of 103 to 108 wherein the polymeric fluorescent substance contains one or more of segments represented by the following formula (1) and one or more of repeating units represented by the following formula (2): 1
    Type: Application
    Filed: November 9, 2001
    Publication date: May 16, 2002
    Applicant: SUMITOMO CHEMICAL COMPANY, LIMITED
    Inventors: Shuji Doi, Yoshiaki Tsubata, Takahiro Ueoka
  • Publication number: 20020033910
    Abstract: Provide is a polymeric fluorescent substance or polymeric fluorescent substance solution which can attain higher luminous efficiency as a polymer LED, with using a polymeric fluorescent substance having a specific content of water or poor solvent, or a polymeric fluorescent substance solution containing a specific content of water or poor solvent.
    Type: Application
    Filed: March 15, 2001
    Publication date: March 21, 2002
    Inventors: Toshihiro Ohnishi, Takanobu Noguchi, Yoshiaki Tsubata, Masato Ueda, Shigeru Sasaki
  • Publication number: 20020027623
    Abstract: Provided is a polymeric fluorescent substance containing specific repeating units at a specific ratio in main chain and having a branching polymeric chain. The substance is excellent in film-forming property without losing solubility in a solvent, and preferably used for a polymer LED having high light-emitting efficiency.
    Type: Application
    Filed: March 30, 2001
    Publication date: March 7, 2002
    Inventors: Shuji Doi, Yoshiaki Tsubata
  • Patent number: 5866035
    Abstract: A liquid crystal mixture containing a compound of the formula (1) as an essential component, which has a large birefringence (.DELTA.n), an increased upper limit temperature of nematic phase and a widened temperature range of nematic phase, and a decreased responsiveness parameter.
    Type: Grant
    Filed: December 26, 1996
    Date of Patent: February 2, 1999
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Chizu Sekine, Kyoko Yamamoto, Yoshiaki Tsubata, Koichi Fujisawa
  • Patent number: 5762825
    Abstract: A liquid crystal mixture containing (a) at least one compound of a compound of the formula (1): ##STR1## in which R is a C.sub.1 -C.sub.12 alkyl group, etc.; X.sub.1, X.sub.2, X.sub.3, X.sub.4, Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 represent, independently each other, CH, CF or N; A is a hydrogen atom, a 4-R.sub.1 -(cycloalkyl) group, etc. in which R.sub. is a C.sub.1 -C.sub.12 alkyl group, etc. and p is 0 or 1; and Z is --C.tbd.C-- or a single bond, and (b) at least one compound of the formula (4): ##STR2## wherein rings C, D, E and F represent, independently each other, 1,4-phenylene, etc. which may be substituted by 1, 2 or 3 fluorine atoms; R.sub.2 is a hydrogen atom, a C.sub.1 -C.sub.12 alkyl group, etc.; R.sub.3 is a hydrogen atom, a fluorine atom, a fluoromethyl group, etc.; Z.sub.1, Z.sub.2 and Z.sub.3 represent, independently each other, --COO--, --OCO--, --OCH.sub.2 --, --CH.sub.2 O--, a C.sub.1 -C.sub.5 alkylene group, a C.sub.2 -C.sub.5 alkenylene group, etc.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: June 9, 1998
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Yoshiaki Tsubata, Kyoko Yamamoto, Koichi Fujisawa, Yukari Fujimoto, Tsutomu Matsumoto, Masayoshi Minai, Chizu Sekine
  • Patent number: 5662828
    Abstract: A compound having an unsaturated side chain represented by the formula: ##STR1## in which A and B are the same and different and represent an aromatic or heterocyclic group or either one of A and B represents a single bond; X.sub.1, X.sub.2 and X.sub.3 are the same or different and represent a hydrogen atom or a lower alkyl group; R.sub.1 represents a saturated or unsaturated alkyl group which may be substituted with a halogen atom or an alkoxyalkyl group which may be substituted with a halogen atom; X represents --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C-- or a single bond; n is an integer of 0 to 6; q is an integer of 1 to 15; p and s are each 0 or 1; and the asterisk * indicates an asymmetric carbon atom, which is useful as an intermediate of a liquid crystal or a monomer of a liquid crystalline polymer.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: September 2, 1997
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Yoshiaki Tsubata, Kayoko Ueda, Koichi Fujisawa, Takayuki Higashii, Masayoshi Minai, Naoyuki Takano, Yukari Fujimoto
  • Patent number: 5554317
    Abstract: A compound having an unsaturated side chain represented by the formula: ##STR1## in which A and B are the same and different and represent an aromatic or heterocyclic group or either one of A and B represents a single bond; X.sub.1, X.sub.2 and X.sub.3 are the same or different and represent a hydrogen atom or a lower alkyl group; R.sub.1 represents a saturated or unsaturated alkyl group which may be substituted with a halogen atom or an alkoxyalkyl group which may be substituted with a halogen atom; X represents --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, --C.ident.C-- or a single bond; n is an integer of 0 to 6; q is an integer of 1 to 15; p and s are each 0 or 1; and the asterisk * indicates an asymmetric carbon atom, which is useful as an intermediate of a liquid crystal or a monomer of a liquid crystalline polymer.
    Type: Grant
    Filed: July 13, 1994
    Date of Patent: September 10, 1996
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Yoshiaki Tsubata, Kayoko Ueda, Koichi Fujisawa, Takayuki Higashii, Masayoshi Minai, Naoyuki Takano, Yukari Fujimoto