Patents Assigned to Hoechst Celanese Corp.
  • Patent number: 5994560
    Abstract: Described herein is a novel process to resolve a racemic compound into its optically active isomers without need for chemical transformation such as salt formation. The process advantageously utilizes polymers containing chiral moieties in their repeat units as well as exhibiting critical solution temperature behavior in a suitable solvent. An embodiment describes the resolution of tryptophan.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: November 30, 1999
    Assignee: Hoechst Celanese Corp.
    Inventors: Hyun Nam Yoon, Mengshi Lu, Naoya Ogata
  • Patent number: 5922828
    Abstract: A novel process to produce polyethylene terephthalate (PET) using a specific catalyst stabilizer system is described. The catalyst stabilizer system is specific for producing PET wherein the polycondensation catalyst is a titanium and the stabilizer possesses an irreversible oxidation potential of at least +2.0 volts versus SCE. The novel process results in PET having acceptable color and low acetaldehyde content.
    Type: Grant
    Filed: August 13, 1997
    Date of Patent: July 13, 1999
    Assignee: Hoechst Celanese Corp.
    Inventor: David Anthony Schiraldi
  • Patent number: 5916506
    Abstract: An antistatic bicomponent fiber includes a nonconductive first component made of a first polymer and a conductive second component made of a second polymer containing a conductive material, where the second polymer has a lower melting point than the first polymer. The bicomponent fiber is made by co-extruding the two polymers at a temperature above their melting points, stretching the extruded fiber to increase the tensile strength, and heat treating the fiber at a temperature between the melting point of the first polymer and the melting point of the second polymer to improve the conductivity of the conductive second component. The bicomponent fiber is preferably a sheath/core fiber.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: June 29, 1999
    Assignee: Hoechst Celanese Corp
    Inventors: Robert Anthony Breznak, Joseph Andrew Foldhazy, Robert Allen Ritchie, Herman Leslie LaNieve, III, Wolfgang Alfred Piesczek
  • Patent number: 5869026
    Abstract: Novel ligands for use in MRI contrast agents and which have the formula ##STR1## wherein R.sub.1 -R.sub.14, M", l, m, and n are defined herein.
    Type: Grant
    Filed: August 21, 1997
    Date of Patent: February 9, 1999
    Assignee: Hoechst Celanese Corp.
    Inventors: Wei-Jen Peng, David E. Reichert
  • Patent number: 5861140
    Abstract: A composition of matter having the formula ##STR1## wherein R.sub.1 -R.sub.14, M, l, m, and n are defined herein and which have application as MRI contrasting agents.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: January 19, 1999
    Assignee: Hoechst Celanese Corp.
    Inventors: Wei-Jun Peng, Daniel A. Aguilar
  • Patent number: 5861138
    Abstract: Novel ligands for use in MRI contrast agents and which have the formula ##STR1## wherein R.sub.1 -R.sub.14, M", l, m, and n are defined herein.
    Type: Grant
    Filed: November 20, 1996
    Date of Patent: January 19, 1999
    Assignee: Hoechst Celanese Corp.
    Inventors: Wei-Jun Peng, Daniel A. Aguilar
  • Patent number: 5851930
    Abstract: A rigid three-dimensionally shaped fiber network structure having improved post-yield dimensional recovery is composed of a deformed textile fabric network structure containing: (A) at least one oriented, semi-crystalline monofilament yarn containing a thermoplastic polymer and disposed in the deformed fabric so as to provide a plurality of monofilament cross-over points therein; and (B) a cured crosslinkable resin impregnating the deformed network structure so as to effect bonding of all or substantially all of the monofilament cross-over points.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: December 22, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: William E. Bessey, Gerald Peter Rumierz, Clinton Dale Felton
  • Patent number: 5851668
    Abstract: A fiber having increased cut resistance is made from a fiber-forming polymer and a hard filler having a Mohs Hardness Value greater than about 3. The filler is included in an amount of about 0.05% to about 20% by weight. In preferred embodiments, the fiber-forming polymer is poly(ethylene terephthalate) or a liquid crystalline polyester comprising monomer units derived from 6-hydroxy-2-naphthoic acid and 4-hydroxybenzoic acid. Preferred fillers include tungsten and alumina.
    Type: Grant
    Filed: November 19, 1996
    Date of Patent: December 22, 1998
    Assignee: Hoechst Celanese Corp
    Inventors: Robert Bruce Sandor, Michele C. Carter, Gunilla E. Gillberg-LaForce, William F. Clear, John A. Flint, Herman Leslie Lanieve, Scott W. Thompson, Etheridge Odell Oakley, Jr., Edward Ronald Kafchinski, Mohammed Ishaq Haider
  • Patent number: 5843609
    Abstract: This invention provides a free-flowing polyester dye microspheric powder which has superior stability and transparency for application in electrophotographic imaging systems. In another embodiment this invention provides a non-aqueous dispersion polymerization process for producing the invention polyester dye microspheric powder. A present invention toner composition comprises polyester dye microspheric powder, and one or more optional ingredients such as a charge control agent or a surfactant.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: December 1, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Marie Borzo, Kophu Chiang, Eui-Won Choe, Rao D. Mikkilineni, Hyun-Nam Yoon
  • Patent number: 5844036
    Abstract: Injection moldable, highly filled polymer composites are provided which exhibit high dimensional stability at temperatures above the glass transition temperature of the matrix polymer. The heat distortion temperature of the composites approaches that of the crystal melting temperature of the matrix polymer. The composite includes a polyaryletherketone matrix and at least two types of fillers each providing unique properties. The first filler is a reinforcing fiber filler which provides high strength and stiffness. The second filler is an non-thermoplastic immobilizing filler to immobilize the amorphous portion of the partially crystalline polyaryletherketone polymer and provide resistance to high temperature distortion. Notwithstanding its improved mechanical and heat resistant properties, the composite remains injection moldable and thus capable of low cost manufacturing.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: December 1, 1998
    Assignee: Hoechst Celanese Corp.
    Inventor: O. Richard Hughes
  • Patent number: 5833321
    Abstract: Automobile seats having improved comfort have a spacer layer included within the layers of cushioning materials. The spacer layer has a large void volume and nearly unrestricted flow of air. Heated, cooled or ambient air can be forced into the spacer layer of the seat, making the seat more comfortable with respect to temperature and removal of perspiration.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: November 10, 1998
    Assignee: Hoechst Celanese Corp
    Inventors: Dai W. Kim, Gregory M. Clark
  • Patent number: 5834122
    Abstract: Disclosed in this invention is an optical filter to enhance the contrast and brightness of images from a color display. The filter comprises suitable dyes and a polymer matrix, applied in a suitable form on the display unit. Such filters have utility in devices based on CRTs, plasmas and the like.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: November 10, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Chia-Chi Teng, Suk Youn Suh, Hyun-Nam Yoon
  • Patent number: 5831087
    Abstract: Macrocycle compounds of precise molecular geometry are disclosed and claimed, useful for a variety of purposes including membranes, molecular recognition and any other purpose where specific molecular macrogeometry is important. Most preferably, the macrocycles are of the imide class, formed by way of reactions of diamines with .alpha.-anhydride, .omega.-nitro compounds, followed by cyclization with an acid chloride.
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: November 3, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Michael Haubs, Marie Borzo
  • Patent number: 5827611
    Abstract: Thermoplastic multicomponent articles are shown wherein the components comprise a polymer matrix wherein one component contains at least one uniformly distributed substantially unreactive low molecular weight, guest molecule or compound which imparts different properties to the component.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: October 27, 1998
    Assignee: Hoechst Celanese Corp
    Inventor: Charles E. Forbes
  • Patent number: 5814711
    Abstract: This invention discloses a novel process to prepare multi-block copolymers with high molecular weights from two immiscible polymer segments. In one embodiment, the two polymer segments are reacted in a solvent mixture which comprises N-methyl-2-pyrrolidinone and diglyme. Such polymers are useful for alignment layer applications in display devices.
    Type: Grant
    Filed: December 5, 1996
    Date of Patent: September 29, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Eui Won Choe, Masayuki Arai, Marie Borzo
  • Patent number: 5801269
    Abstract: Processes for recovering 4,4'-dimethyl bibenzoate (DMBB) from byproduct streams of dimethyl terephthalate (DMT) production are disclosed. The byproduct streams are treated to produce an overhead stream which includes DMBB. In one aspect of the invention, the overhead product stream is added to an organic solvent under conditions sufficient to rapidly form a suspension of crystallized DMBB. In another aspect of the invention, the overhead is dissolved in an appropriate organic solvent and cooled to form a suspension of DMBB crystals in the solvent. A portion of the suspension is removed, and the remaining portion of the suspension centrifuged to recover DMBB crystals. In still another aspect of the invention, the overhead stream is treated with an organic solvent to form a slurry of DMBB crystals, and the resultant slurry thermally treated to increase the concentration of DMBB crystals therein while also solubilizing any organic contaminants.
    Type: Grant
    Filed: April 30, 1997
    Date of Patent: September 1, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Carrie A. Feeney, Ida L. Jones, Bennett C. Ward, Thomas M. Kenesson, Charles B. Hilton, Michael R. Ahern, Gregory M. Adams, Edward M. de la Garza, B. Frank Wood, Jr., Thomas L. Grantland, Kan J. Tsai, James L. Ragan
  • Patent number: 5798432
    Abstract: Liquid crystalline polymers that are made from 4-hydroxybenzoic acid, 2,6-naphthalenedicarboxylic acid, terephthalic acid, hydroquinone, and N-acetyl-4-aminophenol by heating the monomers in the presence of acetic anhydride are more easily synthesized in high molecular weight if isophthalic acid is also included as a monomer at a level of about 0.5 mole % to about 10 mole %.
    Type: Grant
    Filed: March 22, 1996
    Date of Patent: August 25, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Cherylyn Lee, Vincent J. Provino, H. Clay Linstid, III
  • Patent number: 5777129
    Abstract: The present invention provides novel highly branched macromolecule polymers that have highly controlled molecular architectures, and having the formula: ##STR1## wherein R.sub.4, R.sub.5, and R.sub.6 are defined herein.
    Type: Grant
    Filed: August 18, 1995
    Date of Patent: July 7, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Kathleen Nelson Juneau, Richard Vicari, Carl David Murphy
  • Patent number: 5772949
    Abstract: A thermally expandable wax composition and its use in polymer-based actuators is disclosed and claimed. The compositions are wax-based and include conductive filler as well as a viscosity modifier to stabilize the composition against segregation. Optionally included are thermoxidative stabilizers.
    Type: Grant
    Filed: August 7, 1997
    Date of Patent: June 30, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: M. Ishaq Haider, James E. Kuder, Barbara J. Long, Joseph D. Menczel, James B. Stamatoff, Michael Bayer
  • Patent number: 5773591
    Abstract: A novel process for preparing sulfonic acid esters and amides of benzo-heterocyclic diazo diketo compounds, such as substituted diazo-4-oxo-3,4-dihydrocoumarins, which are useful synthetic intermediates in a wide variety of applications including photoresists, opto-electronics, agricultural, and pharmaceutical applications is disclosed and claimed. The process comprises the steps of (a) subjecting a substituted benzo-heterocyclic .beta.-keto-enol compound to suitable diazo transfer conditions in the presence of a diazo transfer agent; (b) subjecting the so formed diazo diketo compound to suitable halosulfonation conditions in the presence of a halosulfonation agent; and (c) subjecting the so formed halosulfonyl aromatic compound to suitable substitution reaction in the presence of an alcohol or an amine to form the corresponding sulfonic acid ester or amide of benzo-heterocyclic diazo diketo compound.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: June 30, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Mohammad Aslam, Michael T. Sheehan, George Kvakovszky