Abstract: Crude diphenyl phthalates, including isomeric mixtures thereof which are prepared by reacting mixtures of isophthalic and terephthalic acids with phenol, preferably in the presence of an organotitanate, organozirconate, or organostannate catalyst, are purified by dissolving the crude phthalate in an organic solvent, contacting the resulting solution with dilute aqueous alkali to neutralize the ester, separating the resulting oil and aqueous phases, and thereafter recovering from the oil phase a purified diaryl phthalate of reduced color and low acidity.
Type:
Grant
Filed:
May 24, 1988
Date of Patent:
September 19, 1989
Assignee:
Celanese Engineering Resins, Inc.
Inventors:
A. Lee Stautzenberger, Ellen A. Langford, Edward E. Quick
Abstract: In one embodiment this invention provides a frequency doubling optical waveguide consisting of a substrate-supported polymeric thin film which exhibits second order nonlinear optical response, and which has a periodic structure for quasi-phase matching of propagating laser wave energy.In a preferred embodiment the waveguide has a two-dimensional channel structure for intensified single mode wave transmission.
Abstract: Ceramic fibers are prepared from improved preceramic fibers having a core comprising an organosilicon preceramic polymer and at least one co-spun sheath layer comprising a synthetic film-forming polymer.
Abstract: A method is described for increasing the brightness of reductively bleached high yield pulps, comprising bleaching the pulps with a reductive bleaching solution under anaerobic conditions and maintaining the bleached pulps under anaerobic conditions during all handling steps subsequent to bleaching, including paper formation, wet pressing, and drying of the paper formed therefrom. The bleached paper has higher brightness than the same paper produced under aerobic conditions, and the bleaching and handling-derived portion of this higher brightness is retained after storage of the finished paper.
Type:
Grant
Filed:
December 23, 1987
Date of Patent:
September 5, 1989
Assignee:
Virginia Chemicals Inc.
Inventors:
S. Allen Grimsley, James C. Robinson, Mark A. Schroeder
Abstract: This invention provides an optical medium which consists of an inorganic glass monolith with a microporous structure containing an organic component which exhibits nonlinear optical response.In one embodiment this invention provides a sol-gel process for producing a composite of a transparent homogeneous microporous inorganic oxide glass monolith and an organic compound which exhibits nonliner optical response.
Type:
Grant
Filed:
October 24, 1988
Date of Patent:
August 29, 1989
Assignee:
Hoechst Celanese Corp.
Inventors:
Tessie M. Che, Dagobert E. Stuetz, Alan Buckley, Donald R. Ulrich
Abstract: In one embodiment this invention provides novel thiazolidine compounds, such as 3-[R-(-)-3-benzyloxycarbonylthiazolidine-4-carbonyl]thiazolidine corresponding to the formula: ##STR1## An invention thiazolidine compound exhibits prolyl endopeplidase inhibitory activity, and has utility as a therapeutic agent for the treatment of dementia and amnesia disorders.
Abstract: Boron-containing ceramics are formed from organoboron precermaic polymers which are carboralated acetylenic poolymers. The polymers can be formed by carboralating acetylenic or diacetylenic diols and condensing the diols to form carboralated polyesters. In an alternative process, polydiacetylene formed by the polymerization of diacetylene monomers having conjugated triple bonds are carboralated subsequent to polymerization. A process for obtaining readily soluble polydiacetylenes comprises heating a diacetylene diol in a high boiling solvent.
Abstract: In one embodiment this invention provides a bistable optical device comprising a Fabry-Perot etalon which has an optical cavity containing a naphthalocyanine dye medium as a nonlinear optical component.
Type:
Grant
Filed:
April 19, 1988
Date of Patent:
August 8, 1989
Assignee:
Hoechst Celanese Corp.
Inventors:
Palaiyur S. Kalyanaraman, Anthony F. Garito
Abstract: In a preferred embodiment this invention provides novel organopolysiloxanes which exhibit nonlinear optical response.Illustrative of an invention organopolysiloxane is a polymer corresponding to the formula: ##STR1## where n is an integer of at least 5.
Abstract: This invention provides novel sidechain liquid crystalline polymers which exhibit nonlinear response, and which have utility as a transparent nonlinear optical component in optical light switch and light modulator devices.
Type:
Grant
Filed:
November 21, 1986
Date of Patent:
August 8, 1989
Assignee:
Hoechst Celanese Corp.
Inventors:
Ronald N. De Martino, Hyun-Nam Yoon, James B. Stamatoff
Abstract: This invention provides an optical medium which consists of an inorganic glass monolith with a microporous structure containing an organic component which exhibits nonlinear optical response.In one embodiment this invention provides a sol-gel process for producing a composite of a transparent homogeneous microporous inorganic oxide glass monolith and an organic compound which exhibits nonlinear optical response.
Type:
Grant
Filed:
April 17, 1987
Date of Patent:
July 25, 1989
Assignee:
Hoechst Celanese Corporation
Inventors:
Tessie M. Che, Dagobert E. Stuetz, Alan Buckley, Donald R. Ulrich
Abstract: This invention provides novel side chain liquid crystalline polymers with a polyester or polyamide main chain structure. An invention polymer exhibits nonlinear optical response, and has utility as a transparent nonlinear optical component in optical light switch and light modulator devices.
Abstract: An oxymethylene polymer composition which exhibits a reduced tendency to form mold deposits upon molding, reduced tendency to discolor under thermal stress and low extractable formaldehyde levels is provided by utilizing as a stabilizer a major amount of superpolyamide and a minor amount of a cyclic amidine compound of the formula: ##STR1## wherein R is phenyl, polynuclear aromatic, heterocyclic, cycloaliphatic and aliphatic containing at least 6 carbon atoms, as well as substituted derivatives of the listed substituents.
Type:
Grant
Filed:
February 9, 1988
Date of Patent:
June 27, 1989
Assignee:
Hoechst Celanese Corporation
Inventors:
Andrew B. Auerbach, James L. Paul, K. M. Natarajan
Abstract: This invention provides novel polyvinyl polymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in electrooptic light modulator devices.
Type:
Grant
Filed:
January 24, 1986
Date of Patent:
May 30, 1989
Assignee:
Hoechst Celanese Corporation
Inventors:
Ronald N. DeMartino, Hyun-Nam Yoon, James B. Stamatoff, Alan Buckley
Abstract: In one embodiment this invention provides a nonlinear optical medium whcih is a transparent film of a thermoplastic polymer composed of recurring monomeric units corresponding to the formula: ##STR1##
Abstract: A continuous process is disclosed for separating components of a hydrocarbon gas stream which are selected from the group consisting of hydrogen, nitrogen, methane, ethylene, ethane, higher saturated and unsaturated hydrocarbons, and mixtures thereof by countercurrently contacting the hydrocarbon gas stream with a physical solvent selected from the group consisting of: (1) paraffinic solvents having molecular weights ranging from 75 to 140 and UOP characterization factors ranging from 12.0 to 13.5, these factors being independent of the aromatic content of the paraffinic solvents, (2) naphthenic solvents having molecular weights ranging from 75 to 130 and UOP characterization factors ranging from 10.5 to 12.
Abstract: A process for producing boron-containing ceramics such as boron carbide and boron nitride comprises pyrolyzing a blend of a precarbonaceous polymer such as polyacrylonitrile and a boron-containing polymer such as that formed by the reaction of a borane with a Lewis base. Pyrolyzation in an inert atmosphere yields boron carbide while pyrolyzation in a reactive gas burns away the precarbonaceous polymer and yiels a ceramic comprising the reaction product of boron and the pyrolyzation gas. Boron nitride ceramics are formed by pyrolyzing the preceramic blend in ammonia.
Abstract: Stripper compositions for coatings comprise an aromatic hydrocarbon, an aliphatic alcohol, and trioxane. Xylene and methanol are the preferred solvents. A useful composition for use at room temperature is 33% xylene, 33% methanol, and 33% trioxane. Trioxane slurries at ambient temperature are also useful for hot dip stripping when heated to a temperature which causes the trioxane to be dissolved.
Abstract: An electrically conductive polyacetal molding resin composition having improved flexibility and impact strength is provided by formulating an oxymethylene polymer, an electrically conductive carbon black having a surface area, BET N.sub.2 of greater than 1,200 m.sup.2 /g and a pore volume, DBP absorption of greater than 500 cc/100 g, and an elastomeric polyurethane.
Abstract: Novel aromatic carboxylic amides of the general formula: ##STR1## wherein each of R.sub.1 and R.sub.2 is a hydrogen atom or an alkyl group having 1-4 carbon atoms, R.sub.3 and R.sub.4 are hydrogen atoms or together form another chemical bond, each X is a hydroxyl group, a halogen atom, an alkyl group having 1-4 carbon atoms and an alkoxy group containing 1-4 carbon atoms, and n is an integer of 1-3 with the proviso that when .[.Xs.]. .Iadd.X's .Iaddend.are alkyl or alkoxy groups, they may be connected together to form a ring, as well as pharmaceutically acceptable salts thereof.These compounds possess a strong antiallergenic action and are thus useful for treatment of asthma, hay fever, .[.anticaria.]. .Iadd.urticaria .Iaddend.and atopic dermatitis.The above aromatic carboxylic amides can be prepared by reacting a reactive functional derivative of the general formula: ##STR2## where R.sub.1, R.sub.2, R.sub.3, R.sub.