Patents by Inventor Volker Reiffenrath

Volker Reiffenrath 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).

  • Liquid-crystalline medium
    Patent number: 6171665
    Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, containing at least one compound of the general formula I wherein R1-R4 may each, independently of one another, be an alkyl or alkenyl radical having up to 12 carbon atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, where one or more CH2 groups in these radicals may also, in each case independently of one another, be replaced by —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O atoms are not linked directly to one another, and —A— is 1,4-phenylene, in which, in addition, one or two CH groups may be replaced by N, 2,3-difluoro-1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or a single bond.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: January 9, 2001
    Assignee: Merck Patent Gesellschaft
    Inventors: Michael Heckmeier, Brigitte Schuler, Volker Reiffenrath
  • Benzene derivatives and liquid-crystalline medium
    Patent number: 6159393
    Abstract: A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, characterized in that it contains one or more compounds of the general formula I ##STR1## in which R, Y, A.sup.1, A.sup.2, Z.sup.1, Z.sup.2, L.sup.1 and m are as defined herein.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: December 12, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Kazuaki Tarumi, Ekkehard Bartmann, Volker Reiffenrath, Sabine Schoen, Detlef Pauluth, Brigitte Schuler, Eike Poetsch
  • Electro-optical liquid-crystal display
    Patent number: 6146720
    Abstract: The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid-crystal layer and which contains a liquid-crystalline medium of positive dielectric anisotropy, where the medium comprises at least one mesogenic compound containing a 3,4,5-trifluorophenyl group and/or comprises at least one mesogenic compound [lacuna] a structural unit of the formula 2 ##STR1## in which A is O or CH,Z is --COO-- or a single bondL.sup.1 is F or, if A is O, is alternatively H, andL.sup.2 is H or F.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: November 14, 2000
    Assignee: Merck Patent Gesellschaft mit
    Inventors: Axel Pausch, Eike Poetsch, Kazuaki Tarumi, Anja Huth, Andreas Wachtler, Andreas Beyer, Brigitte Schuler, Volker Reiffenrath, Matthias Bremer, Michael Kompter
  • Liquid-crystalline compounds, and liquid-crystalline medium
    Patent number: 6146719
    Abstract: A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, including one or more compounds of the general formula I: ##STR1## in which, R is H, an alkyl or alkenyl radical having 1 or 2 to 15 carbon atoms respectively which is unsubstituted, monosubstituted by CN or .sub.CF. or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may also, in each case independently of one another, be replaced by --O--, --S--, ##STR2## --CO--, --CO--O--, --O--CO--, or --O--CO--O-- in such a way that O atoms are not linked directly to one another,m is 0 or 1,n is 0, 1 or 2, andm+n is 1, 2 or 3.
    Type: Grant
    Filed: September 25, 1999
    Date of Patent: November 14, 2000
    Assignee: Merck Patent Gesellschatf mit beschrankter Haftung
    Inventors: Eike Poetsch, Brigitte Schuler, Michael Heckmeier, Volker Reiffenrath, Werner Binder, Joachim Krause
  • Liquid-crystal composition, method of adjusting the resistance, and substituted phenols
    Patent number: 6139925
    Abstract: The present invention relates to liquid-crystal mixtures having specific resistance values, comprising acidic compounds. The present invention furthermore relates to liquid-crystal displays containing these liquid-crystal mixtures. The invention furthermore relates to compounds of the formula I, ##STR1## in which the parameters are as defined in the text, to their preparation, and to their use for achieving certain specific resistance values in liquid-crystal mixtures. The application also relates to a method of adjusting the specific resistance of liquid-crystal mixtures using acidic compounds.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: October 31, 2000
    Assignee: Merck Patent Gesellschaft mit
    Inventors: Michael Darius, Volker Reiffenrath, Kazuaki Tarumi, Bernhard Rieger, Michael Heckmeier, Marcus Reuter, Peer Kirsch
  • Bisalkenylbicyclohexanes, and liquid-crystalline medium
    Patent number: 6126857
    Abstract: The invention relates to bisalkenylbicyclohexanes of the formula I ##STR1## in which R.sup.1, R.sup.2 and Z are as defined in claim 1, and to their use in liquid-crystalline media.
    Type: Grant
    Filed: October 1, 1997
    Date of Patent: October 3, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Volker Reiffenrath, Harald Hirschmann
  • Nematic liquid crystal mixtures and a matrix liquid crystal display
    Patent number: 6083423
    Abstract: The invention relates to a nematic liquid crystal mixture having a positive dielectric anisotropy .DELTA..epsilon. of at least +4 and a birefringence .DELTA.n of at least 0.12, characterized in that the mixtures comprises one or more components having the core structure ##STR1## wherein L.sup.1, L.sup.2, Y and Z are each independently of one another H or F, one of Q.sup.1 and Q.sup.2 is 1,4-phenylene, 3-fluoro-1,4-phenylene or 3,5-difluoro-1,4-phenylene and the other residue Q.sup.1 or Q.sup.2 is --CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 -- or -- if at least one of L.sup.1, L.sup.2, Y and Z denotes F-- also a single bond, whereby this core structure can be optionally further fluorinated in the benzene rings.
    Type: Grant
    Filed: March 12, 1997
    Date of Patent: July 4, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Bernhard Rieger, Volker Reiffenrath, Reinhard Hittich
  • STN liquid crystal display
    Patent number: 6080451
    Abstract: Supertwist liquid crystal displays (STN displays) of excellent characteristics are obtained if the nematic liquid crystal mixtures used therein comprise at least one compound of the formula IA ##STR1## and at least one compound of the formula IB ##STR2## in which R.sup.a, R.sup.b, Z, L.sup.a, L.sup.b, L.sup.c, L.sup.d, L.sup.e, L.sup.f, L.sup.g, L.sup.h, R.sup.3, R.sup.4 are as defined below.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: June 27, 2000
    Assignee: Merck Patent Gesellschaft Mit
    Inventors: Harald Hirschmann, Sven Schupfer, Volker Reiffenrath, Sabine Schoen
  • Liquid-crystalline medium
    Patent number: 6066268
    Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy, which contains at least one compound of formula I ##STR1## and at least one compound of formula II ##STR2## wherein R.sup.1 is alkyl or alkoxy with 1 to 8 C atoms or alkenyl with 2 to 7 C atoms,R.sup.2 is alkenyl with 2 to 7 C atoms,R.sup.3 and R.sup.4 are each independently alkyl or alkoxy with 1 to 8 C atoms, ##STR3## m is 0 or 1.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: May 23, 2000
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Hideo Ichinose, Yuka Ikedo, Yasuyoshi Namiki, Shinji Nakajima, Akiko Takashima, Kazuaki Tarumi, Brigitte Schuler, Volker Reiffenrath
  • STN liquid-crystal display
    Patent number: 6063456
    Abstract: Supertwist liquid-crystal displays (SLCDs) with outstanding properties are obtained if the nematic liquid-crystal mixtures used therein comprise at least one compound selected from the formulae 1A and 1B ##STR1## and at least one compound of the formula 1C ##STR2## in which R.sup.a is alkyl, alkoxy, alkenyl or alkenyloxy having 1 to 12 carbon atoms,R.sup.b is alkyl or alkoxy having 1 to 5 carbon atoms,Z is --COO--, --CH.sub.2 CH.sub.2 -- or a single bond, andL.sup.a, L.sup.b, L.sup.c, L.sup.d, L.sup.e, L.sup.f, L.sup.g, and L.sup.h in each case independently of one another are H or F,with the proviso that the 1,4-phenylene rings carry not more than 2 fluorine atoms per ring,R.sup.3 is an alkenyl group having 2 to 7 carbon atoms,R.sup.4 is R.sup.a or R.sup.3 andc is 0 or 1.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: May 16, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Harald Hirschmann, Sven Schupfer, Volker Reiffenrath, Sabine Schoen
  • TN and STN liquid-crystal display
    Patent number: 6056894
    Abstract: TN liquid-crystal displays and supertwist liquid-crystal displays (SLCDs) having very short response times and good steepnesses and angle dependencies are obtained by using nematic liquid-crystal mixtures which comprise at least one compound of formula IA ##STR1## and at least one compound of the formula IB ##STR2## in which R.sup.a, R.sup.b, R.sup.c, L and r are as defined herein.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: May 2, 2000
    Assignee: Merck Patent GmbH
    Inventors: Harald Hirschmann, Clarissa Weller, Volker Reiffenrath
  • Dopants
    Patent number: 6056893
    Abstract: A dopant compound of the formula IR.sup.1 -(A.sup.1 -Z.sup.1).sub.n -A.sup.2 -W Iin which ##STR1## and R.sup.1, A.sup.1, A.sup.2, Z.sup.1 n, X and R.sup.a are as defined in claim 1, and to the use thereof as chiral dopants in liquid-crystalline media for electro-optical displays, and to electro-optical displays containing such media.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: May 2, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Volker Reiffenrath, Georg Weber
  • Supertwist liquid-crystal display
    Patent number: 6054193
    Abstract: Supertwist liquid-crystal displays having excellent properties are obtained if the nematic liquid-crystal mixture comprises at least one compound of the formula I: ##STR1## and at least one compound of the formula I.sup.* : ##STR2## in which R.sup.1 is alkyl, alkoxy, alkenyl or alkenyloxy having 1 to 12 carbon atoms,R.sup.2 is alkyl or alkoxy having 1 to 8 carbon atoms,Z is --COO--, --CH.sub.2 CH.sub.2 or a single bond,one of the radicals L.sup.1 and L.sup.2 is F and the other is H,Alkenyl.sup.* is an alkenyl radical having up to 7 carbon atoms,L.sup.* is H or F, andR.sup.* is F or an alkyl group having 1 to 12 carbon atoms which is unsubstituted or non-substituted.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: April 25, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Harald Hirschmann, Marcus Reuter, Volker Reiffenrath
  • Electro-optical liquid-crystal display
    Patent number: 6045878
    Abstract: The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid-crystal layer and which contains a liquid-crystalline medium of positive dielectric anisotropy, where the medium comprises at least one mesogenic compound and at least one alkenyl compound of formula I*.
    Type: Grant
    Filed: December 4, 1997
    Date of Patent: April 4, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Kazuaki Tarumi, Andreas Beyer, Volker Reiffenrath, Eike Poetsch
  • Liquid-crystalline medium
    Patent number: 6036884
    Abstract: The invention relates to a liquid-crystalline medium based on a mixture of polar compounds having positive dielectric anisotropy, characterized in that it comprises one or more compounds of the general formula I ##STR1## and simultaneously one or more compounds of the general formula I' ##STR2## in which R.sup.1, R.sup.2, R.sup.0', ##STR3## Y.sup.2' and X.sup.0' are as defined herein.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: March 14, 2000
    Assignee: Merck Patent Gesellschaft mit
    Inventors: Kazuaki Tarumi, Brigitte Schuler, Volker Reiffenrath
  • TN and STN liquid-crystal display
    Patent number: 6028655
    Abstract: The invention relates to TN liquid-crystal displays and supertwist liquid-crystal displays (SLCDs) having very short response times and good steepnesses and angle dependences, and to the novel nematic liquid-crystal mixtures used therein, which are distinguished by the fact that they comprise at least one compound o the formula IA ##STR1## and at least one compound of the formula IB ##STR2## in which R.sup.a, R.sup.b, R.sup.c, Ring A*, L, l and r are as defined in claim 1.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: February 22, 2000
    Assignee: Merck Patent Gesellschaft Mit Beschrankter Haftung
    Inventors: Georg Weber, Harald Hirschmann, Volker Reiffenrath, Ursula Patwal, Dagmar Zimmermann
  • Electro-optical liquid-crystal display
    Patent number: 6027665
    Abstract: The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals, where the field thereof has a significant component parallel to the liquid-crystal layer, comprising a liquid-crystalline medium having negative dielectric anisotropy, where the medium comprises at least one mesogenic compound which contains a group of the formula A ##STR1## and at least one compound which contains a group of the formula B ##STR2##
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: February 22, 2000
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Axel Pausch, Kazuaki Tarumi, Volker Reiffenrath
  • Supertwist liquid-crystal display
    Patent number: 6017469
    Abstract: Supertwist liquid crystal displays with outstanding properties are obtained when the nematic liquid crystal mixture contains at least one compound of the formula (I): ##STR1## where the variables are as defined in the disclosure.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: January 25, 2000
    Assignee: Merck Patent Gesellschaft mit Beschrankter Haftung
    Inventors: Volker Reiffenrath, Bernhard Rieger, Michael Junge, Martina Schmidt, Christine Pfister
  • STN liquid-crystal display
    Patent number: 5997767
    Abstract: The invention relates to supertwist liquid-crystal displays (SLCDs) having very short response times and good steepnesses and angle dependences, and to the nematic liquid-crystal mixtures according to the invention used therein, which are distinguished by the fact that they comprise at least one compound of the formula IA and at least one compound of the formula IB ##STR1## in which R, R.sup.3, R.sup.4 and C are as defined herein.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: December 7, 1999
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Harald Hirschmann, Clarissa Weller, Volker Reiffenrath
  • Electro-optical liquid crystal display
    Patent number: 5993691
    Abstract: The invention relates to an electro-optical liquid-crystal display having a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid-crystal layer and which contains a liquid-crystalline medium of positive dielectric anisotropy, where the medium comprises at least one mesogenic compound containing a 3,4,5-trifluorophenyl group and/or comprises at least one mesogenic compound [lacuna] a structural unit of the formula 2 ##STR1## in which A is O or CH,z is --COO-- or a single bondL.sup.1 is F or, if A is O, is alternatively H, andL.sup.2 is H or F.
    Type: Grant
    Filed: August 4, 1997
    Date of Patent: November 30, 1999
    Assignee: Merck Patent Gesellschaft MIT
    Inventors: Axel Pausch, Eike Poetsch, Kazuaki Tarumi, Anja Huth, Andreas Wachtler, Andreas Beyer, Brigitte Schuler, Volker Reiffenrath, Matthias Bremer, Michael Kompter