Abstract: Filaments characterized by enhanced tensile strength, which are composed of starch acetate or a blend of starch acetate and cellulose acetate and metal chelates, are provided. Also provided are methods for varying the viscosity of a starch acetate solution or starch acetate and cellulose acetate solutions in the production of fibers and cigarette tow.
Abstract: A copolyester composition comprising poly(ethylene naphthalate bibenzoate) ("PENBB") and 0.001 to 5% by weight of fine silica particles having an average diameter of 0.01 to 3.0 .mu.m. Further, films are made from this copolyester composition.
Type:
Grant
Filed:
June 2, 1995
Date of Patent:
October 7, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Cynthia Bennett, E-Won Choe, John Anthony Flint, Bodo Kuhmann
Abstract: The invention provides a novel process to oxidize 1,4-dihydroxy aromatic compounds into the corresponding quinones using sulfuryl chloride as the oxidant. The process is simple and cost effective and provides an efficient way to synthesize hindered quinones.
Abstract: A process for making a transparent film comprising a liquid crystalline polymer, and a transparent film made thereby having high barrier properties. In this process, the LCP is dissolved in an appropriate solvent, then cast into a film at ambient or near-ambient temperatures. The film optionally may be dried at elevated temperatures and/or reduced pressures to remove the solvent. The film is then annealed at a temperature between the glass transition temperature (T.sub.g) and the melting point temperature (T.sub.m) of the polymer. The result is a highly transparent film having liquid crystalline morphology and high barrier properties.
Type:
Grant
Filed:
December 21, 1995
Date of Patent:
September 30, 1997
Assignee:
Hoechst Celanese Corp
Inventors:
Subhash Makhija, M. Ishaq Haider, Edward C. Chenevey, Michael Jaffe
Abstract: This invention provides novel liquid crystalline polymers which, when mixed with a suitable dye and extruded, yields polarizer films with superior polarizing efficiency, transmittance, dichroic ratio, and thermal and humidity stability. The invention further provides a process to prepare such polymers and polarizer films therefrom.
Type:
Grant
Filed:
June 2, 1995
Date of Patent:
September 30, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Sunny S. Shen, Hyun Nam Yoon, Mohammad Mortazavi
Abstract: This invention provides all organic high extinction polarizers based on blends of novel liquid crystalline polymers and suitable dichroic dyes. The invention further provides a process to prepare such polarizer films.
Type:
Grant
Filed:
June 2, 1995
Date of Patent:
September 16, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Mohammad Mortazavi, Hyun Nam Yoon, Chia-Chi Teng
Abstract: An aromatic polyester having recurring monomer units derived from terephthalic acid, 6-hydroxy-2-naphthoic acid, p-hydroxybenzoic acid, 4,4'-biphenol, and resorcinol. This polyester is melt processible and may be amorphous or semi-crystalline.
Abstract: A melt consolidated, multiaxially oriented liquid crystal polymer ("LCP") sheet or other article formed from LCP particles. One embodiment includes a multi-component LCP sheet in which particles of a higher melting LCP are imbedded in a matrix of a lower melting LCP. These LCP components are formed into sheet at a temperature between the melting point of the lower melting matrix LCP and the higher melting reinforcing LCP, so that the imbedded LCP particles may maintain their shape, orientation, and mechanical characteristics while the matrix LCP component flows around the particles and forms a solid sheet. In another embodiment, LCP particles are melt consolidated to form a single article in which a significant amount of LCP orientation is retained. A sheet of this invention may be formed by a variety of processes, and may be made from recycled scrap LCP.
Abstract: Bilayer filaments and fused cords thereof are described. The product is particularly useful for tire cord and filaments include a core of a partially crystalline, oriented polymer and a shell or sheath formed of a blend of robber and a relatively low melting polymer. A particularly preferred embodiment includes a poly(ethylene terephalate) core as well as a sheath of copolyester blended with poly(styrene-elastomer-styrene) elastomer.
Type:
Grant
Filed:
October 26, 1995
Date of Patent:
August 5, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Eui Won Choe, Charles Edward Forbes, Jennifer Ann Filbey, Stephan Fredrick Sherriff
Abstract: A process for the production of N-acylaminophenols by the concurrent hydrogenation of a nitrophenol to an aminophenol and the acylation of the aminophenol with acyl anhydride takes place on a continuous basis in a stirred tank reactor in which liquid product is continuously withdrawn from the reactor. Of particular interest is the manufacture of acetaminophen, N-acetyl-p-aminophenol by continuous reaction of p-ntirophenol, hydrogen and acetic anhydride.
Type:
Grant
Filed:
May 26, 1995
Date of Patent:
July 15, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
James A. Foster, Werner H. Mueller, Debra A. Ryan, Hartmut Wiezer
Abstract: The present invention relates to a water insoluble, aqueous alkali soluble novolak resin blend, wherein the resin blend comprises two novolaks having dissimilar relative molecular weights and similar dissolution rates, a process for producing such a resin blend, a photoresist containing such a resin blend and a method for producing a semi-conductor device utilizing such a photoresist.
Type:
Grant
Filed:
August 5, 1996
Date of Patent:
July 8, 1997
Assignee:
Hoechst-Celanese Corp.
Inventors:
Thomas J. Lynch, Chester J. Sobodacha, Dana L. Durham
Abstract: The present invention is generally directed to multi-component rubber-polyester composites including a sidechain containing copolyester as a compatibilizing component.
Type:
Grant
Filed:
October 26, 1995
Date of Patent:
April 29, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Eui W. Choe, Charles E. Forbes, Jennifer A. Filbey, Stephan F. Sherriff
Abstract: The present invention pertains to polymers comprising poly(4-hydroxystyrene) or substituted poly(4-hydroxystyrene) or both. The polymers have low optical density (absorbance) over a wavelength range from about 240 to about 260 nm, as well as low optical density over the near UV and visible spectrum (310 to 800 nm). Such polymers are produced by polymerizing 4-acetoxystyrene and/or substituted 4-acetoxystyrene monomers, with or without other comonomers, and subsequently performing transesterification. In the most preferred embodiment of the present invention, the polymers are produced using at least one alcohol as a reaction medium, a chain transfer agent and a transesterification reactant, providing an unusually economic process. These polymers are particularly useful as photoresist components for use in combination with deep UV, X-ray, and E-Beam imaging systems.
Abstract: A process for the production of N-alkyl anilines by the concurrent hydrogenation of a nitrobenzene to an aniline and the acylation of the aniline with acyl anhydride takes place on a continuous basis in a stirred tank reactor in which liquid product is continuously withdrawn from the reactor.
Type:
Grant
Filed:
May 16, 1995
Date of Patent:
April 1, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
James A. Foster, Werner H. Mueller, Debra A. Ryan
Abstract: A polypropylene or polyethylene film or fiber coated with a maleic-acid grafted polypropylene or polyethylene copolymer layer over which is coated a layer of selective polymer. The copolymer securely bonds the selective polymer to the film or fiber. These fibers and films can be used in fluid separation membranes.
Type:
Grant
Filed:
May 19, 1992
Date of Patent:
March 25, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Tai-Shung Chung, Edward R. Kafchinski, Rachel S. Kohn, Frank J. Onorato, Jr.
Abstract: The invention relates to multiple fiber connectors for thermoplastic optical couplers and fibers. The multiple-fiber connectors facilitate the connection of optical fibers to a star coupler and provide low levels of light loss between input/output ports of a coupler. The invention further relates to a terminator hot plate apparatus for the semiautomatic termination of optical fiber ends, and a new cladding material for thermoplastic optical couplers and fibers.
Type:
Grant
Filed:
December 22, 1994
Date of Patent:
February 18, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
James E. Kuder, Kevin F. Manning, Pascal J. B. Landi, Elizabeth E. Fernekess, Matthew Cardone
Abstract: Substituted phenethanol ethers are prepared in useful yields by the etherification of corresponding substituted phenethyl alcohols with aliphatic primary alcohols. The etherification is carried out by reacting a substituted phenethyl alcohol with an aliphatic primary alcohol in the presence of an acid catalyst at a temperature of at least about 75.degree. C.
Type:
Grant
Filed:
December 23, 1994
Date of Patent:
February 11, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
John R. Durrwachter, Humberto Ramos, Jr., Mohammad Aslam
Abstract: Composite yarns having exceptional cut resistance are made by combining at least two different kinds of fiber, as follows: (a) a high modulus fiber having a modulus greater than about 200 gpd as measured by ASTM Test Method D-3822; and (b) a particle-filled fiber, which is made from a semi-crystalline polymer, such as poly(ethylene terephthalate), and hard particles having a Mohs Hardness Value greater than about 3.
Type:
Grant
Filed:
November 16, 1995
Date of Patent:
January 28, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Robert B. Sandor, Herman L. LaNieve, III, Robert E. Roschen
Abstract: Multi-component composites containing a linear polyester of an alkyl glycol and an aromatic diacid as one component, rubber as a second component, and a third component which is a compatibilizing polyester (polystyrene copolymer).
Type:
Grant
Filed:
October 26, 1995
Date of Patent:
January 28, 1997
Assignee:
Hoechst Celanese Corp.
Inventors:
Eui W. Choe, Charles E. Forbes, Jennifer A. Filbey, Stephan F. Sherriff
Abstract: PVP-coated asymmetric hollow fibers made from SIXEFT.TM.-Durene, a polyimide made from 2,2-bis[3,4-dicarboxyphenyl] hexafluoropropane dianhydride and 2,3,5,6-tetramethylphenylene diamine monomers, and a process for making such fibers. These coated fibers have a separation factor that exceeds 6 for oxygen and nitrogen and a permeance of at least about 10 ppm cc(STP)/(sec cm.sup.2 cm-Hg). A polymer dope comprising SIXEF.TM.-Durene in a solvent system containing N-methyl-2-pyrrolidone ("NMP") and an organic acid such as propionic acid ("PA") is prepared by polymerizing the polyimide monomers in NMP to form a polyamic acid polymer and imidizing this polymer using the acid anhydride. Water released from the polymer in the imidization reaction converts the anhydride to acid. The dope is wet-spun into hollow fibers; the fibers are coagulated in water. The fibers are then evenly coated with PVP, preferably by dipping the fibers in a dilute PVP solution.