Benzene Rings Linked By Direct Bond Patents (Class 252/299.65)
  • Patent number: 6395351
    Abstract: Compounds with the general formula (I): R—S1—A—Z1—B—S2—R, where A and B are independent ring systems with the formulae (a1), (a2) or (b), whereby in the trans-1,4-cyclohexylene ring, one or two non-adjacent CH2 groups may be replaced by oxygen, and whereby, in the 1,4-phenylene ring, one or two non-adjacent CH groups may be replaced by nitrogen; L1, L2, L3 represent, independently, hydrogen, C1-C20-alkyl, C1-C20-alkenyl, C1-C20-alkyloxy, C1-C20-alkyloxy carbonyl, formyl, C1C20-alkyl carbonyl, C1-C20-alkyl carbonyloxy, halogen, cyano or nitro; Z1, Z2, Z3 represent, independently, a single bond, —CH2CH2—, —CH2O—, —OCH2—, —COO—, —OOC—, —(CH2)4—, —O(CH2)3—, —(CH2)3O— or —C≡C—; S1, S2 represent a spacer unit; R represents crosslinkable groups, with the proviso that at least one of the ring systems A or B represents a ring system with the formula (a1
    Type: Grant
    Filed: November 19, 1999
    Date of Patent: May 28, 2002
    Assignee: Rolic AG
    Inventors: Carsten Benecke, Teodor Lukàc, Angela Ohlemacker
  • Publication number: 20020060310
    Abstract: A polymerizable compound represented by formula (I): 1
    Type: Application
    Filed: November 8, 2001
    Publication date: May 23, 2002
    Applicant: Dainippon Ink and Chemicals, Inc.
    Inventors: Hiroshi Hasebe, Sadao Takehara, Kiyofumi Takeuchi
  • Patent number: 6376030
    Abstract: Nematic liquid-crystal compositions of negative dielectric anisotropy comprising compounds of the formula I are useful in plasma-addressed liquid-crystal displays.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: April 23, 2002
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Michael Heckmeier, Marcus Reuter
  • Patent number: 6372308
    Abstract: A liquid crystal composition includes (1) an anti-ferroelectric liquid crystal compound of formula (1) and (2) a ferrielectric liquid crystal compound or racemic compound thereof. The composition ratio of (1) to (2) is in the range extending from a value which extends from within 5 mol % of the boundary compositional ratio on the anti-ferroelectric phase side and to within 25 mol % of the boundary compositional ratio on the ferrielectric phase side. The boundary compositional ratio is obtained on the basis of a liquid crystal phase diagram prepared on the basis of conoscopic image observations obtained by changing the mixing ratio of (1) and (2). The liquid crystal composition has the following properties: (b) an optical response in a positive voltage region and a negative voltage region and free or substantially free of hysteresis; and (c) excellent alignment stability.
    Type: Grant
    Filed: March 9, 2000
    Date of Patent: April 16, 2002
    Assignee: Mitsubishi Gas Chemical Company INC
    Inventors: Yasue Yoshioka, Masahiro Johno, Tomoyuki Yui, Takahiro Matsumoto
  • Publication number: 20020036285
    Abstract: Disclosed are polymerizable liquid-crystalline compounds of the general formula (I) 1
    Type: Application
    Filed: April 3, 2001
    Publication date: March 28, 2002
    Applicant: BASF Aktiengesellschaft
    Inventors: Frank Prechtl, Robert Parker, Peter Schuhmacher, Norbert Schneider, Sylke Haremza, Hans-Werner Schmidt, Gerold Schmitt
  • Publication number: 20020033474
    Abstract: There is disclosed a liquid crystalline polyacetylene having a repeat structure of the formula 1
    Type: Application
    Filed: February 20, 2001
    Publication date: March 21, 2002
    Inventors: Ben Zhong Tang, Wing Yip Lam, Xiangxing Kong, Hoi Sing Kwok
  • Publication number: 20020031621
    Abstract: The present invention relates to liquid-crystalline compositions of matter comprising, as components,
    Type: Application
    Filed: May 25, 2001
    Publication date: March 14, 2002
    Applicant: BASF AKTIENGESELLSCHAFT
    Inventors: Frank Prechtl, Sylke Haremza, Frank Meyer, Robert Parker, Kathrin Kurschner, Peter Schuhmacher, Hans-Werner Schmidt, Gerold Schmitt, Reiner Giesa
  • Publication number: 20020025390
    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 1
    Type: Application
    Filed: December 11, 2000
    Publication date: February 28, 2002
    Inventors: Michael Heckmeier, Peer Kirsch, Brigitte Schuler, Achim Gotz
  • Publication number: 20020018863
    Abstract: An objective of the present invention is to provide a liquid crystal composition whose orientation undergoes a large change upon irradiation with light, and which also has a large birefringence &Dgr;n. The liquid crystal composition contains an aromatic acetylene compound and a chiral compound that undergoes a structural change upon photoreaction, and has such properties that, upon irradiation with light, its helical pitch undergoes a large change in accordance with the level of the light intensity, and that has a large birefringence &Dgr;n. Therefore, the present invention makes it possible to provide a reflection type color filter which utilizes the liquid crystal composition, and which provides a lighter display with high reflectance. Moreover, the present invention also provides an optical film that can be formed as a thinner film using the liquid crystal composition.
    Type: Application
    Filed: June 6, 2001
    Publication date: February 14, 2002
    Applicant: FUJI PHOTO FILM CO., LTD.
    Inventor: Mitsuyoshi Ichihashi
  • Publication number: 20020015132
    Abstract: A liquid crystal display which carries out matrix driving of a chiral nematic liquid crystal composition, which is capable of displaying an image theron continuously after a turn-off of an electric field applied thereto, by applying an electric field to the liquid crystal composition through a plurality of scan electrodes and a plurality of data electrodes which face and cross each other with the liquid crystal composition in-between. The nematic liquid crystal which is the main element of the liquid crystal composition mainly contains a liquid crystalline ester compound, a liquid crystalline stilbene compound, a liquid crystalline tarphenyl compound or a liquid crystalline tolane compound.
    Type: Application
    Filed: May 17, 2001
    Publication date: February 7, 2002
    Applicant: Minolta Co., Ltd.
    Inventors: Nobuyuki Kobayashi, Takeshi Kitahora, Fumie Motoori, Hideaki Ueda
  • Publication number: 20020005505
    Abstract: The invention relates to chiral compounds of formula I 1
    Type: Application
    Filed: October 4, 1999
    Publication date: January 17, 2002
    Inventor: LOUISE FERRAND
  • Patent number: 6337420
    Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
    Type: Grant
    Filed: March 7, 2000
    Date of Patent: January 8, 2002
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland Defence Evaluation Research Agency
    Inventors: Andrew John Slaney, Damien Gerard McDonnell, Amarjit Kaur Samra, Maurice Stanley, Victoria Minter, John William Goodby, Michael Hird, Simon John Cross, Chu Chuan Dong
  • Patent number: 6326065
    Abstract: Liquid crystalline compounds having a comparatively high voltage holding ratio, high &Dgr;n and high &Dgr;&egr;, and excellent miscibility with known liquid crystalline compounds at low temperatures.
    Type: Grant
    Filed: December 1, 1998
    Date of Patent: December 4, 2001
    Assignee: Chisso Corporation
    Inventors: Yasuhiro Haseba, Shuichi Matsui, Kazutoshi Miyazawa, Hiroyuki Takeuchi, Yoshitaka Tomi, Fusayuki Takeshita, Etsuo Nakagawa
  • Patent number: 6326066
    Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2 are independently (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by -O- and/or -S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2O—,—OCH2—, —CH2CH2—, —CH═CH—,—C≡C—or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the provisos that at least one of the radicals A1 and A2 present in the molecule is  and at least one of Z1 or Z2 is —COO—, are suitable as components of liquid-
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: December 4, 2001
    Assignee: Merck Patent Gesellschaft mit Reschankter Haftung
    Inventors: Eike Poetsch, Volker Meyer, Volker Reiffenrath, Andreas Wachtler, Ulrich Finkenzeller, Hans Adolf Kurmeier, Reinhard Hittich, Bernhard Rieger, David Coates, Simon Greenfield, Robert William Clemitson
  • Patent number: 6294109
    Abstract: A new class of mesogenic compounds has the formula: where R1 is an ester (—COO—) group; R2 is H, NO2, CN, F, or Cl; R3 is H, CH2═CH, or (CH3)3Si; k is 1 or 2; q is 0 or 1; m is from 2 to 16; n is from 2 to 12; r is from 0 to n−1 (but not greater than 3 or 4); s=1 when r=0, s=0 when r≠0; x is from 0 to 4; and * denotes the position of a chiral carbon. Compounds within this class will have a smectic A* phase, and in some cases a smectic C* phase. Mixtures including one or more of these mesogenic compounds will be useful for a variety of applications.
    Type: Grant
    Filed: June 13, 1995
    Date of Patent: September 25, 2001
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Banahalli R. Ratna, Ranganathan Shashidhar, Jawad Naciri, Gregory P. Crawford, Joel M. Schnur
  • Publication number: 20010016238
    Abstract: To improve switching times, especially at low temperatures, one or more reactive liquid crystalline compounds is added to a liquid crystal mixture used in an electroptical system.
    Type: Application
    Filed: December 29, 2000
    Publication date: August 23, 2001
    Applicant: Merck Patent GmbH
    Inventors: David Coates, Owain Llyr Parri, Simon Greenfield, Martin David Tillin, Mark John Goulding, Patrick Nolan
  • Patent number: 6278028
    Abstract: An electroclinic device having two spaced cell walls each bearing electrode structures and treated on at least one facing surface with an alignment layer, a layer of a smectic liquid crystal material enclosed between the cell walls, where the liquid crystal material contains one or more of the compounds described by formula I as defined in the specification.
    Type: Grant
    Filed: March 7, 2000
    Date of Patent: August 21, 2001
    Assignee: The Secretary of State for in Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Andrew John Slaney, Damien Gerard McDonnell, Amarjit Kaur Samra, Maurice Stanley, Victoria Minter, John William Goodby, Michael Hird, Simon John Cross, Chu Chuan Dong
  • Patent number: 6267910
    Abstract: An antiferroelectric liquid crystal composition having a chiral smectic CA* phase composed by blending liquid crystal composition-constituting compounds having the same direction of inclination of optic axis produced by application of an electric field and/or comprised of a mixture of two enantiomers of a liquid crystal material; one having the stereosense (+) and the other having the stereosense (−). The stereosense is defined so that, when the molecule is viewed so that the bond between the core group and the asymmetric carbon is behind the asymmetric carbon atom, the stereosense is (+) if the remaining three groups (or atoms) are arranged clockwise in order of length of the groups (or, if the groups are the same length, in order of their volume), and the stereosense is (−) if the groups are arranged counter clockwise.
    Type: Grant
    Filed: January 22, 1996
    Date of Patent: July 31, 2001
    Assignee: Nippon Soken, Inc.
    Inventors: Hitoshi Hayashi, Akira Takeuchi, Katsuhide Kikuchi, Kenji Takigawa
  • Patent number: 6258296
    Abstract: A fluorine-substituted compound of the following general formula (1) or (2), and a ferrielectric liquid crystal composition comprising the above compound and a specific ferrielectric liquid crystal compound, wherein, in the formula (1), each of X1 and X2 is a hydrogen atom, or one of them is a hydrogen atom and the other is a fluorine atom, p is an integer of 0 to 3 and q is an integer of 1 to 3, and in the formula (2), each of X1 and x2 is a hydrogen atom, or one of them is a hydrogen atom and the other is a fluorine atom, p is an integer of 1 to 3 and q is an integer of 1 to 3.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: July 10, 2001
    Assignee: Mitsubishi Gas Chemical Company INC
    Inventors: Masahiro Johno, Yuki Motoyama, Takahiro Matsumoto, Hiroshi Mineta, Tomoyuki Yui
  • Patent number: 6245258
    Abstract: A smectic liquid crystal material which comprises (1) an antiferroelectric liquid crystal material and/or a liquid crystal material ferroelectric phase and (2) a liquid crystal material having a smectic C phase. The smectic liquid crystal material may be used in a liquid crystal optical element having a spontaneous polarization of 0.06 nC/cm2 to 96 nC/cm2. The smectic material has a low spontaneous polarization value and the curve of light transmittance to applied voltage for the smectic material has a V-shaped characteristic.
    Type: Grant
    Filed: April 13, 1998
    Date of Patent: June 12, 2001
    Assignee: NEC Corporation
    Inventors: Ken-Ichi Takatori, Ken Sumiyoshi, Yoriko Hatada, Jin Matsushima
  • Patent number: 6217954
    Abstract: An anti-ferroelectric liquid crystal composition containing a phenyl triester compound of the formula (1), wherein R1 is a linear alkyl group having 6 to 12 carbon atoms, m is an integer of 0 to 3, n is an integer of 1 to 3, and X1 is a hydrogen atom or a fluorine atom, and an anti-ferroelectric liquid crystal compound of the formula (2),  wherein R2 is a linear alkyl group having 6 to 12 carbon atoms, X2 is a hydrogen atom or a fluorine atom, A is —CH3 or —CF3, r is 0 or 1 and C* is an asymmetric carbon, provided that when A is —CH3, r is 0 and p is an integer of 4 to 10, that when A is —CF3 and when r is 0, p is an integer of 6 to 8, and further than when A is —CF3 and when r is 1, q is an integer of 5 to 8 and p is 2 or 4.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: April 17, 2001
    Assignee: Mitsubishi Gas Chemical Co Inc
    Inventors: Yuki Motoyama, Takahiro Matsumoto, Masahiro Johno, Tomoyuki Yui
  • Patent number: 6217793
    Abstract: Provided are novel acetylene compounds which are useful as a component for a liquid crystal composition used for a liquid crystal element, a liquid crystal composition containing said compounds and a liquid crystal element using said liquid crystal composition. The acetylene compound is represented by Formula (1): n-CmH2m+1—C≡C—A—Z1—B—Y1—R1  (1) wherein m represents an integer of 2 to 24; R1 represents a linear or branched alkyl group, a linear or branched alkoxyalkyl group, a linear or branched alkenyl group, or a linear or branched alkenyloxyalkyl group each of which may be substituted with a halogen atom; R1 may have an asymmetric carbon atom, and the asymmetric carbon atom may be optically active; A and B represents a cyclic group such as a phenylene group, a biphenylene group, a naphthylene group and the like each of which may be substituted with a halogen atom.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: April 17, 2001
    Assignee: Mitsui Chemicals, Inc.
    Inventors: Yoshiyuki Totani, Hiroe Kayashima, Tsutomu Ishida, Masakatsu Nakatsuka
  • Patent number: 6200654
    Abstract: 1,4-disubstituted 2,6-difluorobenzene compound of formula I wherein R is an alkyl or alkenyl radical, A1 and A2, in each case independently of one another, are (a) a trans-1,4-cyclohexylene radical in which a CH2 group may be replaced by —O— and/or —S, (b) a 1,4-phenylene radical in which a CH group may be replaced by N, (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl, Z1 and Z2 are —CO—O—, —O—CO—, —CH2—O—, —OCH2—, —CH2CH2—, —CH═CH—, —C≡C— or a single bond m and n are 0, 1, 2 or 3, (m+n) is 1, 2 or 3, X is R or F, Cl, CF3, —OCF3, or —OCHF2, —OCF5, —CN or —NCS with the proviso that at least one of the radicals A1 and A2 present in the molecule is are suitable as components of liquid-c
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: March 13, 2001
    Assignee: Merck Patent Gesellschaft mit beschrankter Haftung
    Inventors: Eike Poetsch, Volker Meyer, Volker Reiffenrath, Andreas Wachtler, Ulrich Finkenzeller, Hans Adolf Kurmeier, Reinhard Hittich, Bernhard Rieger, David Coates, Simon Greenfield, Robert William Clemitson
  • Patent number: 6197216
    Abstract: A novel ferrielectric liquid crystal compound of the formula (1), wherein R is a linear alkyl group having 6 to 12 carbon atoms, X is a hydrogen atom or a fluorine atom, m is an integer of 1 to 3, n is an integer of 1 to 3, and C* is an asymmetric carbon atom. The ferrielectric liquid crystal compound of the invention characteristically has a ferrielectric phase in a broad temperature range and shows a high speed optical response in spite of a small spontaneous polarization.
    Type: Grant
    Filed: September 28, 1999
    Date of Patent: March 6, 2001
    Assignee: Mitsubishi Gas Chemical Co INC
    Inventors: Takakiyo Mine, Masahiro Johno, Tomoyuki Yui
  • Patent number: 6197389
    Abstract: The present invention provides a ferrielectric liquid crystal compound represented by the following general formula (1), wherein R is a linear alkyl group having of 6 to 12 carbon atoms, X is a hydrogen atom or a fluorine atom, m is an integer of 1 to 3, n is an integer of 1 to 3, and C* is an asymmetric carbon atom. The ferrielectric liquid crystal compound of the present invention has a ferrielectric phase in a broad temperature range and shows a high speed response in spite of a small spontaneous polarization, and accordingly, it is very useful as a practical raw material for liquid crystal display device.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: March 6, 2001
    Assignee: Mitsubishi Gas Chemical Company Inc
    Inventors: Takakiyo Mine, Masahiro Johno, Tomoyuki Yui
  • Patent number: 6180024
    Abstract: Methods, based on the Wittig-Horner reaction, are provided for the synthesis of compounds of formula (I) where m is from 5-150, X and Y are independently selected from: CN, H, OH, COCH3, CO2H, CO2H, CO2R1, where R1 is C1-12 alkyl, NCS, SCN, CF3, CH2X where X is F, Cl, Br, OH, CHF2 and formula (IB), where J for each X and Y group is independently selected from: CH2, single covalent bond, OOC, CO2, O, CH2O, OCH2, CH2CO2, CH2OOC; p=1-20; L for each X and Y group is independently selected from: O, CH2OCO, CO2, S, NH; (a) is defined by formula (IC), where rings A, B and C are independently selected from phenyl, cyclohexyl, pyridine and pyrimidine and may be independently of each other substituted with at least one of Cl or F; linking groups A and B may be selected from single bond, CO2, OOC, CH2O, OCH2, CH2CH2, C≡C; Z is selected from CN, F, Cl, NO2, R, OR, CO2R, CF3, OOCR, NCS, SCN, where R=straight chain or branched chain alkyl and may include from 1-16 carbon atoms and incl
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: January 30, 2001
    Assignee: The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
    Inventors: Keith M Blackwood, Michelle Jones, David Lacey, Alan W Hall, Kenneth J Toyne, Steven Pringle
  • Patent number: 6181407
    Abstract: An electro-optic material that is characterized by short reaction times when working with a low drive voltage. For that, the electro-optic material has a lamellar liquid crystal (10), which contains one or more components and into which chiral molecules (20), whose longitudinal axes (m) are longer than the longitudinal axes of the molecules (10) forming the lamellar liquid crystal, are introduced at a predefined concentration, so that the longitudinal axes (m) of the chiral molecules (20) are tilted, without an external electric field, statistically by a predefined angle (&thgr;m) toward the normal (z) of the layer of the lamellar liquid crystal (10).
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: January 30, 2001
    Assignee: Deutsche Telekom AG
    Inventors: Wolfgang Dultz, Leonid Beresnev, Ashok Bizadar, Wolfgang Haase
  • Patent number: 6177154
    Abstract: Disclosed are (a) liquid crystalline compounds which are essential as component of the liquid crystal compositions, are excellent in miscibility with other liquid crystal compositions, particularly in the miscibility at low temperatures, and expressed by the general formula (1) wherein R0 and R1 independently represent an alkyl group having 1 to 10 carbon atoms; ring A0, ring A1, ring A2, and ring A3 represent 1,4-cyclohexylene group, 1,3-dioxane-2,5-diyl group, 1,4-phenylene group in which one or more hydrogen atoms on the ring may be represented by a halogen atom or R2O group, pyridine-2,5-diyl group, or pyrimidine-2,5-diyl group; Z0, Z1, Z2, and Z3 represent —CH2CH2—, —CH═CH—, —C≡C—, —CH2O—, —OCH2—, —CF2O—, —OCF2—, —COO—, —OCO—, —(CH2)4—, or single bond; Q1 and Q2 represent hydrogen atom or a halogen atom; Q3 represents hydrogen atom, a halogen atom, or R2O g
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: January 23, 2001
    Assignee: Chisso Corporation
    Inventors: Shuichi Matsui, Tugumiti Andou, Kazutoshi Miyazawa, Hiroyuki Takeuchi, Yasusuke Hisatsune, Fusayuki Takeshita, Etsuo Nakagawa
  • Patent number: 6171519
    Abstract: A ferroelectric liquid crystal mixture having a negative value of &Dgr;e and allowing a high speed response and a low voltage driving, as well as a liquid crystal display devise using the crystal mixture of the invention. The ferroelectric liquid crystal mixture according to the invention comprises two or more compounds from at least two different of the following classes of compounds: A. thiadiazoles, B. phenanthrenes, C. 2-fluoropyridines, D. difluorobenzenes, E. meta-substituted aromatic compounds.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: January 9, 2001
    Assignee: Hoechst Research & Technology Deutschland GmbH & Co. KG
    Inventors: Toshiaki Nonaka, Ayako Takeichi, Li Ji, Kazuya Nagao, Rainer Wingen, Javier Manero, Barbara Hornung, Wolfgang Schmidt
  • Patent number: 6171518
    Abstract: The invention relates to a method of preparing an oriented cross-linked polymer, which comprises the steps of orienting and polymerizing a liquid-crystal composition. The liquid-crystal composition comprises a monomer which reduces the order during polymerization. This makes it possible to obtain oriented cross-linked polymers having a low degree of optical anisotropy and optical elements having a relatively low degree of scattering.
    Type: Grant
    Filed: April 22, 1998
    Date of Patent: January 9, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Rifat A. M. Hikmet, Johan Lub
  • Patent number: RE37270
    Abstract: Liquid crystal phases containing components of the formulae I and III have an acceptable combination of threshold steepness, viewing angle and temperature dependence at a low threshold voltage.
    Type: Grant
    Filed: December 5, 1991
    Date of Patent: July 10, 2001
    Assignee: Merck Patent Gesellschaft
    Inventors: Ian Charles Sage, Michael Kevin Chambers, Reinhard Hittich, Georg Weber