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.
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.
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
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.
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.
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.
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
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
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.
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
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.
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.
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.
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.
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
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
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
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
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
Abstract: A rubber-polyester composite comprising a rubber and a core-and-sheath heterocomponent fiber wherein the fiber core is formed from a linear polyester derived from an alkyl glycol and an aromatic diacid, and wherein the fiber sheath is formed from a compatibilizing acid-terminated or isocyanate-terminated polyester. The fiber sheath may also be composed of a blend of a thermoplastic elastomer and the compatibilizing polyester.
Type:
Grant
Filed:
October 26, 1995
Date of Patent:
June 30, 1998
Assignee:
Hoechst Celanese Corp.
Inventors:
Eui Won Choe, Charles Edward Forbes, Jennifer Ann Filbey, Stephan Fredrick Sherriff