Abstract: A polyacetal binder is removed from an extruded or injection molded ceramic green body in less than 25 hours by a variable heating rate schedule in which the heating rate is reduced when the temperature of the green body reaches the point at which isothermal degradation of the polyacetal binder can take place and wherein at least 80 wt. % of the binder can be removed. In air, the isothermal removal of the binder can take place within the range of 160.degree.-220.degree. C. while in nitrogen the range is from about 300.degree.-360.degree. C.
Abstract: A filler-containing polyolefin resin composition comprising a resin composition composed of a polyolefin resin and an inorganic filler exhibits an excellent thermal stability despite the presence of the inorganic filler by adding thereto a particular phenolic antioxidant, an amide or monoglyceride compound of a higher fatty acid and a particular metal inactivating agent.
Abstract: The present invention relates to an impact resistant polymeric composition comprising a polyarylene sulfide, a thermally stable modified selectively hydrogenated high 1,2 content block copolymer wherein at least one graftable functional molecule is grafted to the block copolymer in the vinylarene block and a silane.
Abstract: This invention provides process embodiments for fabrication of organic optical waveguides. A preferred invention optical waveguide consists of a thin film matrix of three electrodes, one of which has a spatial periodic structure, and a side chain polymeric waveguiding medium positioned between two side chain polymeric cladding layers. The electrodes are adapted to apply electric fields of opposite polarity and to pole the polymer side chains bidirectionally in a noncentrosymmetric orientation of periodic reverse polarity. The waveguiding medium and cladding thin films exhibit second order nonlinear optical susceptibility .chi..sup.(2), and are adapted to phase-match propagating radiation waves.
Type:
Grant
Filed:
October 23, 1990
Date of Patent:
October 29, 1991
Assignee:
Hoechst Celanese Corporation
Inventors:
Garo Khanarian, Pascal Landi, David Haas, Robert Norwood
Abstract: In one embodiment this invention provides vinylidene cyanide copolymers with alternating monomeric units as illustrated by the following structure: ##STR1## An invention vinylidene cyanide copolymer in the form of an electret film exhibits a high level of longitudinal piezoelectric effect, and has excellent processability properties. An electret film which has an external electric field-induced noncentrosymmetric dipolar molecular orientation exhibits second order nonlinear optical susceptibility under light propagation conditions.
Abstract: The polyester comopsition is improved in properties at low and high temperatures and is prepared by mixing 100 parts by weight of a mixture comprising (A) 60 to 99 parts by weight of a crystalline thermoplastic polyester resin and (B) 1 to 40 parts by weight of a polyester elastomer with (C) 0.01 to 5 parts by weight of a bisoxazoline compound, (D) 0.01 to 5 parts by weight of a phosphorus compound represented by the general formula: ##STR1## wherein R.sub.1 and R.sub.2 may be the same or different from each other and are each a group selected from among alkyl, substituted alkyl, aryl, substituted aryl and alkoxy groups, and (E) 0.01 to 5 parts by weight of one or more antioxidants selected from among thio ether compounds and hindered phenol compounds.
Abstract: A novel method is disclosed for the preparation of 2,3-pyridine-dicarboxylates by the reaction of a ketoester such as dimethyl oxalacetate with an .alpha.,.beta.-unsaturated aldehyde or ketone such as 2-ethylacrolein and at least 1 molar equivalent of ammonium salt in suitable solvent.
Type:
Grant
Filed:
July 1, 1988
Date of Patent:
September 10, 1991
Assignee:
Hoechst Celanese Corporation
Inventors:
B. Franklin Gupton, James H. Rea, Werner H. Mueller, John Saukaitis
Abstract: The present invention relates to an impact resistant polymeric composition comprising a polyarylene sulfide and a thermally stable modified selectively hydrogenated high 1,2 content block copolymer wherein at least one graftable functional molecule is grafted to the block copolymer in the vinylarene block.
Abstract: An injection moldable ceramic composition is prepared by mixing a sinterable powder, a polyacetal binding agent and silicon carbide whiskers which have been coated with a polyacetal resin.
Type:
Grant
Filed:
December 18, 1989
Date of Patent:
August 27, 1991
Assignee:
Hoechst Celanese Corp.
Inventors:
Hongkyu Kim, George L. Collins, O. Richard Hughes
Abstract: A process for rapidly removing the binder from a greenbody composed of a sinterable powder dispersed within a polyacetal binder is achieved by contacting the molded ceramic greenbody with an acid which depolymerizes the polyacetal binder.
Abstract: A PET-polymer composite of 0-3 connectivity further includes a third phase particulate additive of conductive or semiconductive material to increase the electrical conductivity of the polymer matrix.
Type:
Grant
Filed:
June 1, 1990
Date of Patent:
August 27, 1991
Assignee:
Hoechst Celanese Corp.
Inventors:
Geon Sagong, Ahmad Safari, Sei-Joo Jang
Abstract: This invention provides novel side chain copolymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in all-optical and electrooptical light switch and light modulator devices.
Type:
Grant
Filed:
February 7, 1990
Date of Patent:
August 20, 1991
Assignee:
Hoechst Celanese Corp.
Inventors:
Diane Allen, Cherylyn Lee, Ronald N. DeMartino
Abstract: A process for the preparation of anthraquinone compounds comprises reaction of phthalic anhydride with a benzene derivative in a reaction mixture containing HF and BF.sub.3 as catalyst at a first temperature up to about 30.degree. C. and, subsequently, at an elevated temperature.
Abstract: Vent gas from the condenser-scrubber system of a reactor, in which dithionites are made by reacting a formate, sulfur dioxide, and an alkali in aqueous methanol, is reduced in its ethylene oxide content to less than 10 ppm maintaining the ratio of sulfur dioxide to ethylene oxide entering the scrubber to greater than 1.0, preferably greater than 2.5, and most preferably greater than 3.0 and at a temperature of -20.degree. C. to 0.degree. C.
Type:
Grant
Filed:
May 18, 1990
Date of Patent:
July 23, 1991
Assignee:
Hoechst Celanese Corporation
Inventors:
Charles E. Winslow, Jr., Joseph L. Bush
Abstract: Normal aldehydes are produced in high selectivity by the vapor phase reaction of lower olefins with hydrogen and carbon monoxide in the presence of supported liquid phase catalysts at temperatures of 80.degree. C. to 100.degree. C. under pressures of 1 to 5 atmospheres.
Type:
Grant
Filed:
January 8, 1990
Date of Patent:
April 30, 1991
Inventors:
Russell S. Drago, Mark J. Barnes, Michael J. Naughton
Abstract: Polyarylene sulfide molding compositions are provided with improved mold release properties by the inclusion of an internal lubricant comprising stearyl erucamide.
Abstract: A polyarylate is formed by reacting a mixture of a diester of a dihydric phenol, at least one aromatic dicarboxylic acid and an inert diluent comprising a poly(fluorinated alkylene oxide). Polyarylates of improvided color can be formed and the diluent can be easily separated from the polyarylate and reaction byproducts.
Type:
Grant
Filed:
January 12, 1990
Date of Patent:
April 2, 1991
Assignee:
Hoechst Celanese Corporation
Inventors:
Richard Vicari, John R. Costanza, Ronald R. Lamonte, Ralph M. Miano
Abstract: A novel process for the preparation of 3-chloro-4-hydroxyacetanilide in high yields is disclosed which involves reacting N-acetyl-para-aminophenol (APAP) with sulfuryl chloride (SO.sub.2 Cl.sub.2) as the chlorine source and liquid SO.sub.2 as the reaction medium.
Abstract: Preceramic fibers are produced by dissolving a solid organosilicon preceramic polymer in a solvent to form a spinning solution containing at least seventy percent polymer solids, dry spinning and extracting solvent in the presence of a non-oxidizing gas at a temperature and pressure sufficient to vaporize solvent from the fiber, and at least one curing agent being added to the non-oxidizing gas or spinning solution, or both, to induce on-line curing of the fiber or to aid in subsequent curing of the fiber or both. The preceramic fibers are thereafter pyrolyzed to ceramic form.
Type:
Grant
Filed:
May 17, 1989
Date of Patent:
March 5, 1991
Assignee:
Hoechst Celanese Corp.
Inventors:
Robert M. Mininni, M. Ishaq Haider, Stuart M. French, John L. Wesley
Abstract: The carbonylation of an alcohol to produce a carboxylic acid, especially methanol to produce acetic acid, in a low water reaction medium containing a rhodium catalyst stabilized with an iodide salt, especially lithium iodide, along with alkyl iodide such as methyl iodide and alkyl acetate such as methyl acetate in specified proportions is improved by the addition of hydrogen in the feed gas to the low water reaction medium to obtain a reactor hydrogen partial pressure of at least about 4 psi. The presence of hydrogen in the reaction medium increases significantly the carbonylation reaction rate and reduces formation of byproduct carbon dioxide. The present reaction system not only provides an acid product of unusually low water content at unexpectedly favorable reaction rates but also, whether the water content is low or, as in the case of prior-art acetic acid technology, relatively high, is characterized by unexpectedly high catalyst stability; i.e.
Type:
Grant
Filed:
August 5, 1987
Date of Patent:
February 19, 1991
Assignee:
Hoechst Celanese Corporation
Inventors:
G. Paull Torrence, Joel D. Hendricks, Dennis D. Dickinson, Adolfo Aguilo