Abstract: Curable compositions which are useful for encapsulating electrical connections and for joining metals to metals, and which comprise a mixture of high and low molecular weight fluorocarbon elastomers. Preferred compositions comprise a mixture of three fluorocarbon elastomers, the first having a Mooney viscosity at 121.degree. C. of at least 120, the second a Mooney viscosity at 121.degree. C. of 80 to 110, and the third a Brookfield viscosity at 100.degree. C. of 1,000 to 4,000 centipoises, in amounts 5 to 50%, 25 to 70% and 5 to 50% respectively, based on the weight of the polymeric component. The compositions can be easily molded under heat and pressure, and after they have been cured, they have remarkable resistance to degradation by hot liquids, even under pressure. Consequently, the compositions are very useful in the manufacture of self-regulating heaters for use in heating the production tubes of oil wells.

Abstract: A cable and method for making such cable is disclosed. The cable is especially suited for high frequency applications in which electrical attenuation and dissipation factor are of critical importance. The cable comprises a tubular outer conductor, and at least one inner conductor for transmission of electrical signals. Between the inner and outer conductor is a foamed dielectric material. This dielectric is formed from the extrusion of an olefin polymer or a fluoropolymer with a blowing agent gas. Sulfurhexafluoride (SF.sub.6), rather than environmentally unsafe chlorofluorocarbons, is used as a blowing agent to foam the dielectric.

Abstract: A sensor cable for detecting and locating liquid chemicals, especially hydrocarbons, and/or water leaks without interruption of the system, wherein two or three conductors and appropriate insulation are arranged in a configuration that provides circuits for detecting and locating liquid chemicals and for detecting and locating liquid water.

Abstract: A reinforced coaxial electric cable having low dielectric constant and a layer of convoluted dielectric insulation placed between either center conductor and conductive shield, optional porous dielectric and shield, or shield and jacket. FEP convoluted dielectric and expanded polytetrafluoroethylene insulation.

Abstract: The present invention relates to improved elements for use in fuel cell stacks, and more particularly, to a stack having a corrosion-resistant, electrally conductive, fluid-impervious interface member therein.

Abstract: A method for extruding, stretching and sintering polytetrafluoroethylene in a single pass operation to form tubular articles of low density, low matrix tensile strength, sintered polytetrafluoroethylene and articles such as electric cable having low density, low matrix tensile strength sintered polytetrafluoroethylene insulation applied about a conductor by such method. A high reduction ratio rating polytetrafluoroethylene powder with a lubricant is extruded by an extruder having a low reduction ratio, and the extrudate is heated to remove the lubricant and is stretched prior to sintering of the polytetrafluoroethylene tube which is held in its previously stretched state during sintering.

Abstract: A heat and oil-resistant electric insulated wire comprises a conductor coated with an insulating layer which is formed of a vinylidene fluoride-based fluororubber and a silicone rubber added thereto. The amount of silicone rubber added is in a range of 2 to 30 parts by weight, preferably 5 to 20 parts by weight per 100 parts of said fluororubber, said fluororubber being a vinylidene fluoride-propylene hexafluoride copolymer and/or a vinylidene fluoride-propylene hexafluoride-ethylene tetrafluoride terpolymer.

Abstract: The invention relates to a robot arm with a work arm connected to it, a connector moved by motors for tools, workpieces, workpiece grippers or gripper change systems, whereby the motors are located at the end of the work arm opposite the connector, and are connected by output connections with gear wheels mounted in a swiveling axis of a swiveling head of the connector. To make such a robot arm flexible, and moreover to guarantee that the work arm is rigid, it is proposed that the axes (D,E,P) of rotation of the elements (work arm 2, swiveling head 23, connector 3) intersect at a common intersection point (A).

Abstract: A ribbon, preferably made of polytetrafluoroethylene and preferably in an unsintered configuration but having lens or trapezoidal cross section is used for wrapping elongated stock such as electrical conductors, tubes, or a removable mandrel, the wrapping to be made with overlapping edges followed by fusion to obtain a coherent tubular configuration.

Abstract: This application discloses cables insulated with a flexible homogenous and smooth composition which consists essentially of an interdispersion of low density polyethylene and polychloroprene ingredients and at least an effective amount of fibrous polytetrafluoroethylene interdispersing agent effective to homogenously blend said ingredients.

Abstract: A fluorine-containing elastomeric electric insulating material is disclosed. The material is a vulcanized product of a composition comprising 100 parts by weight of a fluorine-containing elastomeric copolymer having a number average molecular weight of from 20,000 to 60,000, containing as major components a unit based on tetrafluoroethylene and a unit based on an .alpha.-olefin having 2 to 4 carbon atoms and exhibiting rubber elasticity at room temperature, 0.1 to 5 parts by weight of an organic peroxide and 0.1 to 20 parts by weight of a polyallyl compound.

Abstract: An electric cable having at least one conductor and at least one covering therefor obtained from the polymerization of a silanic monomer of a compound comprising a non-cross-linked base-polymer and a polymerizable silanic monomer present prior to polymerization in a quantity not less than 5 parts by weight with respect to 100 parts by weight of the base-polymer. Thepolymerization of the silanic monomer units forms a polymeric mesh which is closely interconnected and thoroughly compenetrated into the non-cross-linked base-polymer. In one embodiment the polymeric mesh may be grafted onto the base-polymer through the addition of an organic peroxide. Thus, there is provided an electric cable for use as building wires wherein the conductor covering is not cross-linked but is heat resistant to temperatures above the deformation temperature of the base-polymer.

Abstract: This invention provides a method of increasing the cut-through resistance of a PTFE insulated conductor. Unsintered PTFE is expanded and compressed and then applied to a conductor. The insulated conductor is then heated to a temperature above 345.degree. C. The compressed, expanded PTFE has one crystalline melt point above 375.degree. C.

Abstract: Curable compositions which are useful for encapsulating electrical connections and for joining metals to metals, and which comprise a mixture of high and low molecular weight fluorocarbon elastomers. Preferred compositions comprise a mixture of three fluorocarbon elastomers, the first having a Mooney viscosity at 121.degree. C. of at least 120, the second a Mooney viscosity at 121.degree. C. of 80 to 110, and the third a Brookfield viscosity at 100.degree. C. of 1,000 to 4,000 centipoises, in amounts 5 to 50%, 25 to 70% and 5 to 50% respectively, based on the weight of the polymeric component. The compositions can be easily molded under heat and pressure, and after they have been cured, they have remarkable resistance to degradation by hot liquids, even under pressure. Consequently, the compositions are very useful in the manufacture of self-regulating heaters for use in heating the production tubes of oil wells.

Abstract: In an excellent windability magnet wire wherein an insulating layer of a synthetic resin film is formed on a conductor directly or with another insulation in between and a lubricant layer is formed on the insulating layer, the lubricant layer is made of an intimate mixture of natural wax as a major constituent and thermosetting and fluorocarbon resins compounded therewith.

Abstract: This invention relates to the use of ethylene/tetrafluoroethylene (ETFE) or ethylene/chlorotrifluoroethylene (ECTFE) polymers to produce a foamed coating of insulation over wire and used as wire pairs for transmitting electronic signals, in which the foamed coating is surrounded by a protective jacket or skin made of one of the two polymers.

Abstract: An electrical transmission line of the twisted pair of coaxial cable type is provided. One line has a center conductor, a porous plastic dielectric disposed around the outer periphery of the conductor, the dielectric having specific gravity of 0.5 or less, and having a plastic dielectric sheath disposed around the outer periphery of the porous dielectric, the outer sheath having a melting temperature which is 60% or less than the melting temperature of the porous plastic dielectric. The porous plastic dielectric may be in tape form helically wrapped around the conductor, preferably at a wrap angle of 20 degrees or less. The preferred porous dielectric is expanded polytetrafluoroethylene.

Abstract: Electrical insulation comprises (1) an inner layer of a cross-linked polymer, e.g. polyethylene, an ethylene/tetrafluoroethylene copolymer, an ethylene/chlorotrifluoroethylene polymer or a vinylidene fluoride polymer, and (2) an outer layer of an aromatic polymer having a glass transition temperature of at least 100.degree. C., e.g. a polyether ether ketone, a polyether ketone or a polyether sulfone. Such insulation combines excellent properties under normal service conditions with low smoke evolution on burning, and is therefore particularly useful for aircraft wire and cable.

Abstract: The invention concerns a method for producing a coaxial cable intended for the transmission of very high frequency signals. This coaxial cable comprises a dielectric insulating layer composed of foamed polytetrafluoroethylene or a composition comprising at least 80% of this product named hereinafter COMPOUND. The layer of insulating material is directly obtained by cold extrusion of a COMPOUND powder, the intimate mixing of a pore-forming agent and a foaming agent and a lubricating oil. The mixing of the COMPOUND powder, the pore-forming and foaming agents is effected dry or in aqueous dispersion. Principal application: Fields of use of ultra-high frequencies such as radars and transmissions.

Abstract: For use as a heat sealable, high temperature, insulative wrapping, a laminar structure of a polyimide inner layer and two fluoropolymer outer layers wherein the outer layers are pigmented for a combination of color, increased heat aged bond retention, and reduced heat seal energy requirements.

Abstract: A low attenuation high frequency coaxial cable is provided for carrying microwave energy in the gigaHertz range. A center conductor is wrapped with a plurality of layers of low density PTFE dielectric material. At least one layer of high density unsintered PTFE dielectric material is tightly wrapped around the low density tape with overlapping edges and then is sintered for forming an envelope strong enough to hold the low density material in position during the remainder of the cable preparation and during an attaching of terminating connectors. An outer conductor of longitudinally extending, parallel, adjacent electrically conductive wire strands is applied with a slight helical lay around the dielectric of the cable along its axis thereof surrounding the high density tape. A serving may be applied over the longitudinal wire strands and a jacket applied around the cable over the serving. The cable so formed provides an improvement in performance.

Abstract: An electrical conductor is coated with a cured, lubricating polyester type wire enamel, where the polyester type wire enamel, before heat reaction, contains acid, and hydroxyl components containing fluorinated alcohol and non-fluorinated polyol, and where a fluorinated aliphatic alcohol having a perfluoroalkyl group from 4 carbon atoms to 12 carbon atoms constitutes from 8 wt. % to 30 wt. % of the total fluorinated alcohol plus non-fluorinated polyol content of the unreacted wire enamel.

Abstract: A method of making an electrical cable in which an inner electrical conductor is loosely carried within the interior of an outer sheath. The inner conductor has a length in excess of the length of the sheath such that the cable is better able to withstand stretching and bending without damage to the inner electrical conductor.

Abstract: An improved power cable for a heating system that utilizes the skin effect of alternating current, and a method and apparatus for joining lengths of the improved cable. In one embodiment, the cable includes a stranded copper conductor (20) surrounded by a semiconductive layer (22) formed by carbonized tetrafluoroethylene (TFE) tape which is surrounded by a primary insulation layer (24) formed by pressure extruded, perfluoroalkoxy resin (PFA), the thickness of which is determined by an equation that considers the eccentric positioning the power cable in a heat tube (14). In a second embodiment, the cable comprises a central conductor (30) surrounded by a semiconductive layer (32), followed by a primary insulation layer (34) formed by pressure extruded PFA. A shield layer (36) formed by a layer of semiconductor material (38) and several helically wrapped drain wires (40) surrounds the primary insulation layer. A protective PFA jacket (42) is pressure extruded over the shield layer.

Abstract: A method for extruding, stretching and sintering polytetrafluoroethylene in a single pass operation to form articles of low density sintered polytetrafluoroethylene and articles such as electric cable (C) having low density, sintered polytetrafluoroethylene insulation (F) applied about a conductor (W) by such method.

Abstract: Electrical insulation comprises (1) an inner layer of a cross-linked polymer, e.g. polyethylene, an ethylene/tetrafluoroethylene copolymer, an ethylene/chlorotrifluoroethylene polymer or a vinylidene fluoride polymer, and (2) an outer layer of an aromatic polymer having a glass transition temperature of at least 100.degree. C., e.g. a polyether ether ketone, a polyether ketone or a polyether sulfone. Such insulation combines excellent properties under normal service conditions with low smoke evolution on burning, and is therefore particularly useful for aircraft wire and cable.

Abstract: An improved multiconductor ribbon cable the conductors having at least two layers of polytetrafluoroethylene (PTFE) insulation, a porous unsintered inner layer, that is, the one closest to the conductors, and an impermeable sintered outer layer. Webs of impermeable sintered PTFE connect the insulated conductors. The process for manufacturing the cable includes embedding the conductors between inner sheets of expanded unsintered PTFE and outer sheets of extruded unsintered PTFE, then compressing the sheets only in the web region to high density, and sintering the webs plus the outer insulation layer.

Abstract: An improved flat cable in which parallel, spaced conductors are embedded in an expanded, porous polytetrafluoroethylene insulation and then placed between layers of polytetrafluoroethylene having a higher dielectric constant than the porous insulation. The dielectric constant between conductors can be varied.

Abstract: A jacketed electrical cable construction has low smoke and flame spread characteristics so that it is suitable for use in plenum air spaces in buildings with drop ceilings without the need for metal conduits. The cable includes a bundle of conductors which are insulated with poly(vinylidene fluoride), a wrapping of poly(tetrafluoroethylene) impregnated glass tape surrounding the bundle of conductors and a jacket of poly(vinylidene fluoride).

Abstract: A method of making a cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes enclosing a multiconductor core (22) in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape. The tapes are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.

Abstract: A cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes a multiconductor core (22) which is enclosed in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape which are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.

Abstract: An insulated electrical conductor is provided that exhibits excellent physical, electrical and chemical protection for wire and cable and is particularly suitable for use in aircraft applications. The electrical conductor is insulated with (A) a film selected from ethylene tetrafluoroethylene copolymer film and fluorinated ethylene-propylene (FEP) copolymer coated polyimide film and (B) a topcoat insulation system comprising (a) a first layer of polyimide, (b) a second layer of polyvinylidene fluoride, and (c) a third layer of crosslinked acrylic polymer.

Abstract: The electrical contact is described which incorporates a fluorocarbon polymer film as the lubricant. A process for applying the lubricant is also described. Such contacts are advantageous because of reduced wear behavior and reduced thickness requirements for noble metals used on contact surfaces.

Abstract: Mixtures of (a) copolymers of ethylene and tetrafluoroethylene, which in addition optionally contain up to 10 mole % of units of at least one ethylenically mono-unsaturated monomer copolymerizable with tetrafluoroethylene, with (b) phosphorus acids which in one of their tautomeric forms contain 2 or 3 oxygen atoms and 1 or 2 hydrogen atoms directly bonded to each phosphorus atom, or with salts of such acids, are described. These mixtures possess improved heat stability and can, where appropriate with interpolation of a melt granulation process, be used, in particular, for the coating of metals. Component (b) is added to the copolymer (a) in the dry form or preferably in the form of a solution during working up, and in particular is added either to the pulverulent copolymer or, more especially, to a moist product, isolated from dispersions, after the last washing process.

Abstract: Two coaxial metal pipes, whose confronting extremities are each provided with a plurality of peripheral ribs of staggered height separated by two or more peripheral grooves, are interconnected by a coupling sleeve of fiber-reinforced thermosetting resin subdivided into several coaxially interleaved and independently deformable cylindrical shells each terminating in a pair of internal beads engaged in a respective peripheral pipe groove. The shells, increasing in axial tensile strength from the innermost to the outermost one, are preferably separated from one another by interposed antibonding layers of thermoplastic resin. A resinous filler can be inserted between the pipe extremities for electrically insulating them from each other. The shells of the coupling sleeve can be formed by coiling resin-coated filaments around the pipe axis, advantageously with application of an antifriction layer on each inner shell before the thermosetting material thereof has been fully hardened.

Abstract: An electrical insulating material having anti-tracking properties has incorporated therein an erosion inhibiting fluorine-substituted compound. The electrical insulating material comprises a polymeric material having an anti-tracking filler and the fluorine-substituted compound is a hydrophobic, non-ionic compound having a fluorine-substituted aliphatic carbon chain linked to a group having an affinity for the polymeric material and/or the anti-tracking filler. The electrical insulating material may be used in high voltage applications where it is necessary to resist erosion and/or control leakage currents.

Abstract: The utility of a coaxial electret cable transducer as a hydrophone at shallow depths (low hydrostatic pressure) is extended for operation at substantially greater depths (high hydrostatic pressure) by the combination of the electret with a polymer material having piezoelectric properties, i.e., a piezoid. The electret and piezoid are separate flexible materials radially stacked within the cable or alternatively and preferably constitute a single material formed to have both electret and piezoelectric properties. One substance useful as the piezoid or as the electret-piezoid combination is polyvinylidene fluoride (PVF.sub.2).The invention also comprehends the method of measuring underwater soundings at either low or high hydrostatic pressures with the aforementioned coaxial cable as an electrostatic transducer by measuring electrical signals generated across the cable conductors when the ambient pressure is low and as a piezoelectric transducer across the conductors when such pressure is high.

Abstract: A heating tube adapted to electrically heat a fluid carried therethrough includes an inner tubular layer of polytetrafluoroethylene, a second tubular layer surrounding the inner layer and being formed of a homogeneous mixture of polytetrafluoroethylene and electrically conductive carbon, and a third layer surrounding the second layer and being formed of polytetrafluoroethylene. The three layers are coextruded together. The third layer is cut away at at least two circumferential points and the exposed second layer is there provided with a sintered coating for finely divided silver and finely divided polytetrafluoroethylene. The sintered coating is then wrapped with a silicone resin tape containing dispersed silver particles and a metal ring is then fitted over the silicone resin tape thereby forming an electrical terminal for the heating tube.

Abstract: A composition comprising a polymer having a processing temperature of at least 200.degree. and from about 0.1 wt % up to about 30 wt % of crosslinking agent said crosslinking agent comprising a compound of the formula ##STR1## wherein X is hydrogen and Y is ##STR2## and X and Y are substituents on adjacent carbon atoms of A or wherein X and Y together form the imide ring system ##STR3## which is joined to A on adjacent carbons atoms, thereof, wherein A is an aromatic, heteroaromatic, alicyclic, or heterocyclic system or an open chain aliphatic moiety, where R is vinyl, allyl, methallyl or propargyl and wherein R' is hydrogen, C.sub.1 to C.sub.12 alkyl or R and mixtures thereof.Compounds per se and articles manufactured from the above-indicated polymer compositon are also taught.

Abstract: Electrical wire and cable suitable for use in nuclear generating stations, having at least one electrical conductor, a micaceous insulating layer surrounding the conductor and a layer of fluoropolymer insulation surrounding the micaceous layer.

Abstract: Stabilized fluoropolymer compositions comprising a polymer from about 40 to 60 mol percent ethylene, about 60 to 40 mol percent chlorotrifluoroethylene and optionally about 0.1 to 10 mol percent of a fluorinated termonomer selected from the group consisting of 3,3,3-trifluoro-2-trifluoromethyl propene, a vinyl monomer which is free of telogenic activity and which provides a side chain having at least two carbon atoms, the side chain being aromatic or having its elements bonded by a single bond only, and mixtures thereof, and as a stabilizing agent, a member selected from the group consisting of epoxy resins, mixtures of tribasic lead sulfate and bisphenol A, and mixtures of the epoxy resin, tribasic lead sulfate and bisphenol A.

Abstract: An electrically heatable floor covering comprising a carpet of woven fibers, wherein an electrical heating element is enclosed in the carpet body, which is made of a straight thin copper wire having a reinforcing coating of polytetrafluoroethylene which causes the wire to withstand impressions produced by footsteps and by heavy furniture without being broken.

Abstract: An electrically insulated conductor adapted to be used at high temperatures in power plants, refineries and chemical process plants for connecting instruments has at least one pair of electrical conductors insulated with an irradiation cured ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer or polyvinyl chloride polymer and a drain wire enclosed in a metallic shield and an irradiation cured halosulfonated polyethylene, polychloroprene or chlorinated polyethylene jacket.

Abstract: A cable for detecting, in a stable and waterproof way, any leak of petroleum, petroleum product, or other fluid from an underground pipeline by means of a change in the electrostatic capacity between inner and outer conductors of the cable due to permeation by the leaking fluid. The cable offers constant, uninterrupted monitoring of such a pipeline with no limit to the watching range, and can accurately locate even a minor leak. The invention also involves a method of installing a detection system using such a detector cable, and a detection method which depends on electric pulses as means for detecting such a leak.

Abstract: Lamination of thermoplastic fluorocarbon resins with unsintered, extruded PTFE is accomplished in order to insulate products, such as conductors in the manufacture of multiconductor cable, by drawing the unsintered PTFE containing the product embedded in it pressed against the thermoplastic fluorocarbon resin through a sintering zone to melt the thermoplastic resin and snter the PTFE, thereby laminating the two together. In the preferred arrangement a second PTFE tape, which can be sintered or unsintered tape, is also laminated at the same time to the thermoplastic resin, such that the final product essentially presents PTFE outer surfaces with thermoplastic fluorocarbon resin bonding the layers of PTFE.

Abstract: A composition comprising a polymer having a processing temperature of at least 200.degree. and from about 0.1 wt % up to about 30 wt % of crosslinking agent said crosslinking agent comprising a compound of the formula ##STR1## wherein X is hydrogen and Y is ##STR2## and X and Y are substituents on adjacent carbon atoms of A or wherein X and Y together form the imide ring system ##STR3## which is joined to A on adjacent carbons atoms, thereof, wherein A is an aromatic, heteroaromatic, alicyclic, or heterocyclic system or an open chain aliphatic moiety, where R is vinyl, allyl, methallyl or propargyl and wherein R' is hydrogen, C.sub.1 to C.sub.12 alkyl or R and mixtures thereof.Compounds per se and articles manufactured from the above-indicated polymer composition are also taught.