Abstract: A simplified process for converting bis-phenols to dianilines is disclosed. Selected catalytic complexes are used to cause a nucleophilic displacement reaction between a bis-phenol and a quinazoline to occur thereby yielding a bis-quinazoline that may be subsequently converted into a bis-quinazolinone and hydrolyzed to form the desired dianiline.
Abstract: Improved multicomponent fluorozirconate glasses, doped with chlorine, and a process for making them are disclosed that are continuously transmissive in the infrared spectrum.
Type:
Grant
Filed:
August 26, 1981
Date of Patent:
July 27, 1982
Assignee:
Hughes Aircraft Company
Inventors:
Morton Robinson, Ricardo C. Pastor, Morris Braunstein
Abstract: Improved diimide and polyimide oligomers containing phenylacetylene terminal groups have been produced which melt at low temperatures and are curable into useful laminating resins, molding compounds and matrix resins. These oligomers are analogous to diimides and polyimides made from conventional dianhydrides, such as benzophenonetetracarboxylic dianhydride or pyromellitic dianhydride.
Abstract: Disclosed is a method of producing metal halide and metal chalcogenide crystals for infrared window application which exhibits a high conversion ratio.
Abstract: Chemically stable polymers in aqueous alkaline solutions are dissolved in a strongly polar solvent, thoroughly dispersed from this solvent into and throughout the interstices of porous inorganic fabrics and subsequently separated from said solvent by precipitation to provide a homogeneous reinforcement of the structural properties of said fabrics.
Type:
Grant
Filed:
October 2, 1978
Date of Patent:
November 11, 1980
Assignee:
Hughes Aircraft Company
Inventors:
Hong S. Lim, Howard H. Rogers, Scott A. Verzwyvelt
Abstract: We have prepared a new class of polymeric fibers and masses which are produced by precipitation from solutions of the polymer. The fibers and fiber masses have novel and useful characteristics. A fiber mass of this invention is a coherent, three-dimensional network of interconnected crystalline polymeric fibers and fiber bundles randomly arrayed in all directions. The fibers are smaller in diameter than can be consistently produced by conventional fiber drawing and spinning techniques.The novel fiber masses are produced from solutions of fiber-forming linear organic polymers having regularly repeated chain structures. The polymers are precipitated from these solutions by simultaneously cooling and agitating the polymer solution at vibrations in the sonic frequency range. The fiber masses may then be removed from the solvent or, in the case of a polymerizable solvent, a composite may be formed.
Abstract: An improved process for generating nascent bromine through the pyrolytic dissociation of CBr.sub.4 is shown to be applicable to the growth of large single crystals of metal bromides from the melt.
Abstract: An apparatus and method for epitaxial film formation is disclosed. Planar reactive evaporation techniques suitable for scaling are employed to produce high purity compound semiconducting films at relatively low temperatures.
Abstract: Reflective mode dynamic scattering displays are disclosed which operate under dc excitation for extremely long hours with excellent contrast. These displays are the results of a combination of a high reflectivity cathode, obtained by the use of silver mirror electrodes, with a redox doped ester liquid crystal in an otherwise conventional liquid crystal cell arrangement.
Abstract: A tetrafluoromethane (CF.sub.4) generator and process is disclosed that facilitates the relatively low temperature production of CF.sub.4 gas via controlled decomposition of polytetrafluoroethylene (Teflon) and tetrafluoroethylene (C.sub.2 F.sub.4). CF.sub.4 produced via this process proves to be an excellent OH.sup.- scavenger in the processing and growth of metal fluoride single crystals.
Abstract: Infrared (IR) holograms are fabricated from holograms recorded with visible light in photographic silver halide emulsions. The process facilitates image reconstruction at longer IR wavelength than presently considered possible with conventional IR holographic materials.
Abstract: A new class of copolymers obtained via the copolymerization of diethynylbenzene with an ethynyl-substituted polyimide oligomer has been used to prepare composite materials exhibiting zero void content. The copolymers are thermosetting in character and are particularly useful for the fabrication of composite structures such as glass fiber reinforced laminates and molding compounds and graphite fiber reinforced laminates and molding compounds.
Abstract: Alkali metal halide crystals exhibiting substantially improved physical and optical transmission characteristics are grown from starting powders by a one step Reactive Atmospheric Processing (RAP) method.
Abstract: Self-lubricating composites of high thermal stability, excellent frictional characteristics and wear resistance are formulated from molybdenum disulfide, tungsten disulfide, molybdenum diselenide and thermosetting acetylene-substituted polyimide oligomers.
Abstract: Metallocenes when mixed with conjugated cyano-organic compounds such as 7,7'8,8'-tetracyanoquinodimethane (TCNQ) and (2,4,7,-trinitro-9-fluorenylidene)-malononitrile (TFM) function as excellent dopants for liquid crystals.
Abstract: An apparatus and method for epitaxial film formation is disclosed. Planar reactive evaporation techniques suitable for scaling are employed to produce high purity compound semiconducting films at relatively low temperatures.
Abstract: A process is disclosed whereby infrared holograms can be recorded in photographic silver halide emulsions as positive images. High resolution holograms have been produced with 1.06 .mu.m radiation in photographic plates by utilizing the Herschel reversal effect.
Abstract: A new insulation system, useful for the fabrication of high voltage transformers, capacitors and power supply encapsulation and insulation for high voltage leads, has been developed which substantially eliminates corona and improves reliability of these devices.
Type:
Grant
Filed:
April 15, 1974
Date of Patent:
September 7, 1976
Assignee:
Hughes Aircraft Company
Inventors:
Alfred W. Schwider, John Burnham, Robert S. Buritz
Abstract: Single crystals, useful as laser emission compounds, having the formula ARF.sub.4 wherein A is potassium, sodium, or lithium, and R is holmium, yttrium, erbium, or dysprosium are prepared by a direct congruent melt crystal growth process that yields crystals exhibiting substantially superior physical and chemical characteristics compared to those grown by conventional methods.