Abstract: A process for reaction injection molding of ceramic articles is disclosed. The process comprises (a) injecting a fluid, non-dilatant mixture comprising a ceramic powder, a metal powder or mixtures thereof, and a curable ceramic precursor that is a liquid below its curing temperature, into a heated mold, (b) curing the ceramic precursor to produce a hardened molded article, (c) heating the hardened molded article under a suitable atmosphere to a temperature sufficient to convert the ceramic precursor to a ceramic, and (d) sintering the ceramic to the desired density.
Abstract: Compositions of ketene dimer and nonreactive hydrophobe compound and method for internally sizing paper therewith are provided, wherein the melting point of said hydrophobe compound is higher than the melting point of the ketene dimer.
Abstract: Disclosed is a method of treating a skin lesion comprising applying to the lesion a dry bandage comprising a gas- and moisture-permeable, flexible, thermoplastic film impregnated with a pharmaceutical.
Abstract: A tackifier resin is prepared by polymerizing a monomer mixture of 10-70% piperylene concentrate and 30-90% of a vinyl aromatic monomer in the presence of a boron trifluoride catalyst and an inert diluent. The resin is water white in color, has a Gardner number of less than one, a softening point of 60.degree. to 120.degree. C. and a polydispersity of 1 to 5. The tackifier is used in formulations based on EVA, block copolymers and polyolefins for hot melt and pressure sensitive adhesive applications.
Type:
Grant
Filed:
June 7, 1991
Date of Patent:
January 5, 1993
Assignee:
Hercules Incorporated
Inventors:
Sung G. Chu, Norman E. Daughenbaugh, Jr., Mark J. Rosner
Abstract: One or more layers of a sheet comprising (1) 60% to 99%, based on the weight of solids, of vermiculite delaminated by mechanical means only, (2) 1% to 40%, based on the weight of solids, of at least one fibrous material and (3) 0.1% to 4%, based on the weight of the vermiculite, of at least one flocculating agent, can be used to protect heat-sensitive substrates such as resin matrix composites from fire or heat.
Type:
Grant
Filed:
May 7, 1991
Date of Patent:
January 5, 1993
Assignee:
Hercules Incorporated
Inventors:
Herbert T. Conner, David H. Dumas, Lawrence L. Nelson
Abstract: A tool for using in aligning, fastening, supporting, and sealing adjacent sections of a mandrel having a curved outer surface is provided. This tool has a T-shaped cross section and includes a leg section that has a composite sheet extending through the middle of it and a top section that is integral with said leg section. The top section has a pair of grooves therein spaced apart from each other along the length of the tool where O-ring means fits in the grooves and seals the adjacent section of the mandrel gas tight.
Type:
Grant
Filed:
October 25, 1990
Date of Patent:
December 22, 1992
Assignee:
Hercules Incorporated
Inventors:
Sandra M. Charlson, Steven J. Kotula, Michael R. McCloy
Abstract: A process for the manufacture of improved water soluble polyaminopolyamide-epichlorohydrin resins is disclosed. The polyaminopolyamide-epichlorohydrin reaction is continued until between 70% to 100% of the total charge of epichlorohydrin has reacted. The polyaminopolyamide-epichlorohydrin mixture is then treated with a specified amount of a halogen-free mineral acid. Preferably the mineral acid is selected from the group consisting of sulphuric acid, phosphoric acid, nitric acid and sodium hydrogen sulphate. Following the completion of the acid addition the reaction is continued to effect at least a 10% reduction in the polymer bound organochlorine concentration, based on the composition of the reaction mixture at the time of the acid addition.
Abstract: A crosslinked polymer composition obtained by the metathesis polymerization of a dicyclopentadiene monomer in which a chlorinated polymer such as a chlorinated elastomer or chlorinated polypropylene is dissolved; a crosslinked dicyclopentadiene polymer composition comprising a ring-opened dicyclopentadiene polymer and a dicyclopentadiene-soluble chlorinated polymer; and a method for preparing a crosslinked polymer composition comprising adding the chlorinated polymer to one of two reactant liquid streams, one of which contains dicyclopentadiene and a ring-opening metathesis catalyst and the other contains a catalyst activator, combining the two streams, and charging them to a mold or similar forming container in which the dicyclopentadiene polymerizes.
Abstract: This invention is directed to a composition comprising (A) a continuous phase of (i) a crosslinked organosilicon polymer or crosslinkable organosilicon prepolymer comprising alternating (a) cyclic polysiloxane or tetrahedral siloxysilane residues and (b) polycyclic hydrocarbon residues derived from polycyclic polyenes having at least two non-aromatic, non-conjugated carbon-carbon double bonds in their rings linked through carbon to silicon bonds, wherein at least one of the cyclic polysiloxanes or tetrahedral siloxysilanes (a) or the polycyclic polyenes (b) used to form the polymer or prepolymer has more than two reactive sites; or (ii) a crosslinked or crosslinkable linear poly(organohydrosiloxane) polymer having at least 30% of its .tbd.
Abstract: Range resolution in an FMCW radar system is achieved by providing a periodic linear frequency sweep. The present invention assures the linearity of this sweep by using a negative feedback circuit which includes means for obtaining 16 sequential instantaneous frequency versus time slope measurements during each sweep cycle, generating a set of 16 sequential error signals and a corresponding set of correction voltages, and applying these correction voltages to the sweep drive voltage used to drive the voltage controlled oscillator that generates the frequency swept output signal.
Abstract: This invention provides shielded and wireless connectors for interconnecting electronic circuit boards that are stacked in metal carriers. Serial interconnectors through the carriers provide transmission line paths through the stacked layers through connector assemblies embedded in and fed through each carrier in collinear alignment with each other. Each of the embedded feed through connector assemblies has upper and lower button connectors interconnected by a metal conductor, all positions within an axial hole formed by a pair of substantially cylindrical dielectric inserts. The upper and lower button connectors protrude from the upper and lower surfaces of the upper and lower adjacent circuit boards, respectively. This invention provides connector assemblies having the ability to withstand very high inertial forces without degradation of the electrical contact with the metal pads of the respective circuit boards.
Type:
Grant
Filed:
September 27, 1991
Date of Patent:
December 8, 1992
Assignee:
Hercules Defense Electronics Systems, Inc.
Inventors:
Franklin S. Burkett, Jr., Allen Fernandez
Abstract: Fillers and pigments, such as clay, titanium dioxide, calcium carbonate, silicas, and silicoaluminates, can be rendered cationic by treating the fillers or pigments with the reaction product of a polyamine or polyamide and epichlorohydrin. The resulting water soluble cationic fillers or pigments are useful in the paper industry as fillers for paper and can also be utilized in coating paper.
Abstract: A container providing controlled atmospheric storage of produce (i.e., fresh fruits, vegetables and flowers) to improve retention of product freshness by adjusting the carbon dioxide to oxygen ratio, for the storage of said produce, can be attained and maintained, thereby retarding premature maturation and spoilage. The environment is controlled by providing a microporous membrane panel of a uniaxially or biaxially oriented microporous polyolefin coated with a cured silicone elastomer, said panel being of limited carbon dioxide and oxygen permeance on an otherwise substantially impermeable container. The size of the area of the panel is a function of its permeance, the amount and respiration rate of the contents, and the ratio of carbon dioxide to oxygen desired.
Abstract: An innerliner for tubeless tires is comprised of at least one non-elastomeric barrier layer such as poly(vinylidene chloride) or ethylene--vinyl alcohol copolymer film with each barrier layer sandwiched between two layers of an elastomeric material adhering to the rubber stock employed in the carcass of the tire. The innerliner has the advantage of imparting equal or better air retention properties to the tire with a substantial reduction in the thickness and weight relative to conventional halobutyl rubber innerliners.
Abstract: A composition that comprises a (thio)amide-modified silazane polymer containing at least one alkenyl or alkynyl group and a free radical generator can be crosslinked by an energy input provided in the form of heat, ultraviolet radiation, or an electron beam. The crosslinked (thio)amide-modified silazane polymer composition can be pyrolyzed to form a silicon nitride-containing ceramic.
Abstract: Biaxially oriented film is post-treated by an annealing process in a limited temperature range of 45.degree. C. to 120.degree. C. for various time periods based on the temperature for annealing in order to produce a film having less than a 0.2% shrinkage in the machine direction as measured at 51.7.degree. C. for 24 hours. This film has a wide range of uses, such as overwrapping film.
Abstract: Crosslinked or crosslinkable organosilicon polymers and prepolymers comprising either (i) alternating (a) cyclic polysiloxane or tetrahedral siloxysilane residues and (b) polycyclic hydrocarbon residues derived from polycyclic polyenes having at least two non-aromatic, non-conjugated carbon-carbon double bonds in their rings linked through carbon to silicon bonds, wherein at least one of the cyclic polysiloxanes or tetrahedral siloxysilanes (a) or the polycyclic polyenes (b) used to form the polymer or prepolymer has three or more reactive sites; or (ii) a linear poly(organohydrosiloxane) polymer having at least 30% of its .dbd.SiH groups reacted to hydrocarbon residues derived from polycyclic polyenes having at least two non-aromatic, non-conjugated carbon-carbon double bonds in their rings; wherein the polymer or prepolymer further comprises a coupling monomer having at least one carbon-carbon double bond which reacts with SiH during hydrosilation.
Type:
Grant
Filed:
December 31, 1990
Date of Patent:
September 15, 1992
Assignee:
Hercules Incorporated
Inventors:
Andrew B. Woodside, Raymond T. Liebfried
Abstract: The invention is directed to a solar thermal propulsion engine which comprises:(a) an ogive solar collection cavity with inner and outer walls having therebetween a heat exchange medium which can pass and heat a propellant fluid, and having its highest temperature deep within the cavity, and (b) a nozzle attached to and communicating with the heat exchange medium through which the heated propellant fluid can be passed to create thrust. In addition, this invention is directed to a solar thermal propulsion engine which comprises. (a) a heat exchanger having a geometry such that it has inner and outer walls having therebetween an open cell foam heat exchange medium through which a propellant can pass with tubulence, wherein solar radiation can heat the inner wall and the open foam heat exchange medium to, in turn, heat the propellant, and (b) a nozzle attached to and communicating with the open cell foam heat exchange medium through which the heated propellant fluid can be passed to creat thrust.
Abstract: Disclosed is a process for making a composite sheet using papermaking techniques. The composite sheet comprises (1) 20% to 99%, based on the weight of solids, of vermiculite delaminated by mechanical shearing only, (2) 1% to 80%, based on the weight of solids, of at least one fibrous material and (3) 0.1% to 10%, based on the weight of the vermiculite, of at least one flocculating agent.
Abstract: A solid propellant rocket motor comprising a motor case, solid propellant and at least one end closure, wherein at least one end closure is connected to the casing by at least one fusible connector which melts at temperatures below those that will cause autoignition of the motor but does not melt during normal propulsion, so that the end closure releases before the antoignition and is retained in place during normal propulsion.
Type:
Grant
Filed:
October 4, 1990
Date of Patent:
March 2, 1993
Assignee:
Hercules Incorporated
Inventors:
Charles C. Cherry, Raymond E. Wiechering