Abstract: A method of measuring inductance or inductive reactance of a sample is provided. The method comprises the steps of: (a) providing an instrument for measuring the inductance or the inductive reactance of the sample; (b) subjecting a portion of the instrument to different temperatures and recording data corresponding to the performance of the instrument portion at each temperature; (c) measuring the inductance or the inductive reactance of the sample using the instrument; and (d) correcting the measurement of inductance or inductive reactance for temperature based on the performance data.

Abstract: A method for measuring the level of stress in a polymeric or pre-polymeric composition within a given volume that includes combining the polymeric or pre-polymeric composition with a plurality of microparticles having a non-ferromagnetic or non-ferrimagnetic core provided with a coating that is ferromagnetic or ferrimagnetic to form an admixture in which the microparticles are substantially uniformly dispersed throughout the composition. The microparticles have a detectable magnetic characteristic which correlates with level of stress in the composition within a given volume. The change in the magnetic characteristic of the microparticles is then measured to determine the level of stress in the composition within a given volume.

Abstract: Disclosed is a composite material comprising a matrix material comprising a microwave transmissive polymer; and from about 1 to 65 volume percent of a particulate filler dispersed in the matrix. This particulate filler is characterized by an electrically conductive coating on the filler particles, particles selected from spheroids and ellipsoids having a major dimension below about 0.5 mm and particles having an aspect ratio greater than about 2 to 1 having a minor dimension below 100 &mgr;m, and a combination of particle size and coating thickness sufficient to yield a combination of a composite material dielectric constant between about 1.2 to 100, and a composite material microwave loss tangent no greater than about 0.10 at 1 GHz.

Abstract: Multilayered film and film based assembly which are environmentally-compatible, and which exhibit one or more desirable characteristics of polyvinyl chloride (PVC) film and film based assemblies, such as clarity, flexibility and toughness, but without the environmental and health hazards associated with PVC materials, are provided. Also provided is a method of preparing such film and film based assembly.

Abstract: A method for measuring the quantity of a polymeric or pre-polymeric composition within a given volume that includes combining the polymeric or pre-polymeric composition with a plurality of microparticles having a non-ferromagnetic or non-ferrimagnetic core provided with a coating that is ferromagnetic, ferrimagnetic, or conductive, to form an admixture in which the microparticles are substantially uniformly dispersed throughout the composition. The microparticles have a detectable electromagnetic characteristic which correlates with the amount of the composition within a given volume. The electromagnetic characteristic of the microparticles is then measured to determine the quantity of the composition within a given volume.

Abstract: A method for measuring the level of stress in a polymeric or pre-polymeric composition within a given volume that includes combining the polymeric or pre-polymeric composition with a plurality of microparticles having a non-ferromagnetic or non-ferrimagnetic core provided with a coating that is ferromagnetic or ferrimagnetic to form an admixture in which the microparticles are substantially uniformly dispersed throughout the composition. The microparticles have a detectable magnetic characteristic which correlates with level of stress in the composition within a given volume. The change in the magnetic characteristic of the microparticles is then measured to determine the level of stress in the composition within a given volume.

Abstract: A composition comprising: (1) a susceptor of magnetically coupled radio frequency energy comprising a non-magnetic particulate substrate, e.g., an electrically insulative material in particulate form, bearing a thin magnetic coating, e.g., a magnetic inorganic film, and (2) a matrix that is substantially non-reflective of radio frequency energy, e.g., silicone rubber, which matrix can be heated upon the composition's being subjected to magnetically coupled radio frequency energy. It has been discovered that thin magnetic coatings on non-magnetic particles provide energy transfer with induction heaters equal to or better than many commonly used solid susceptor particles. It has also been discovered that the temperature of the composition of this invention can be regulated so as not to exceed a predetermined temperature.

Abstract: Multilayered film and film based assembly which are environmentally-compatible, and which exhibit one or more desirable characteristics of polyvinyl chloride (PVC) film and film based assemblies, such as clarity, flexibility and toughness, but without the environmental and health hazards associated with PVC materials, are provided. Also provided is a method of preparing such film and film based assembly.

Abstract: A composition comprising: (1) a susceptor of magnetically coupled radio frequency energy comprising a non-magnetic particulate substrate, e.g., an electrically insulative material in particulate form, bearing a thin magnetic coating, e.g., a magnetic inorganic film, and (2) a matrix that is substantially non-reflective of radio frequency energy, e.g., silicone rubber, which matrix can be heated upon the composition's being subjected to magnetically coupled radio frequency energy. It has been discovered that thin magnetic coatings on non-magnetic particles provide energy transfer with induction heaters equal to or better than many commonly used solid susceptor particles. It has also been discovered that the temperature of the composition of this invention can be regulated so as not to exceed a predetermined temperature.

Abstract: Composition comprising (a) susceptors having the capability of absorbing microwave energy, said susceptors comprising a particulate substrate substantially non-reflective of microwave energy and a coating capable of absorbing microwave energy, and (b) a matrix substantially non-reflective of microwave energy. Susceptors are typically particles having a thin-film coating thereon. The matrix typically comprises polymeric or ceramic materials that are stable at temperatures conventionally used in microwave cooking. The composition allows reuse of the susceptors, eliminates decline in heating rate, eliminates arcing, allows the heating rate to be controlled, allows overheating to be controlled, and allows formation of microwave heatable composite materials having very low metal content.

Abstract: The invention provides semi-conductive, static dissipative polymeric composites comprising:a) an insulative polymeric resin, andb) from about 5 to about 35 volume percent of at least one high aspect ratio filler having a thin-film inorganic layer of from about 10 .ANG. to about 1000 .ANG. of a highly conductive metal and an overlayer of an insulative metal oxide, said layer having an average coating thickness of from about 2 .ANG. to about 200 .ANG.,the composites having volume resistivities of from about 1.times.10.sup.4 ohm-cm to about 1.times.10.sup.11 ohm-cm.

Abstract: An electromagnetic radiation absorbing material comprises doubly layered core particles dispersed in a dielectric binder material. The first layer dissipates radiation; the second layer is an insulating material which helps prevent the particles from conductively contacting each other, and prevents degradation of the first layer. The absorber may be applied to an electrically conductive material, and an impedance matching material may be used.

Abstract: Composition comprising (a) susceptors having the capability of absorbing microwave energy, and (b) a matrix substantially non-reflective of microwave energy. The susceptors comprise a particulate substrate having a thin-film coating thereon. The particulate substrate is substantially non-reflective of microwave energy and the coating is capable of absorbing microwave energy. The matrix typically comprises polymeric or ceramic materials that are stable at temperatures conventionally used in microwave cooking. The composition allows reuse of the susceptors, eliminates decline in heating rate, eliminates arcing, allows the heating rate to be controlled, allows overheating to be controlled, and allows formation of microwave heatable composite materials having very low metal content.

Abstract: A method and article for microwave bonding of thermoplastic pipe such as that used in the distribution of natural gas. The article is a composite bonding material (CBM) having a thermoplastic matrix (preferably polyethylene) which is miscible with the thermoplastic material of the pipe, and a plurality of microwave susceptor particles dispersed throughout the matrix. The preferred susceptors have improved heating properties whereby the total amount of metal oxide material in the CBM is about 1/10 of 1% by weight. A strip or sleeve is fashioned from the CBM and may be used, with or without a coupling, to join two pipes or repair ruptures. The method includes positioning of the article at the pipe joint or rupture, and application of microwave energy in an amount sufficient to heat the susceptors and cause both the CBM matrix and the adjacent portion of the pipe to melt and flow together, thereby producing a fusion bond.

Abstract: A method and article for microwave bonding of thermoplastic closures such as that used in splicing telecommunications wires. The article is a composite bonding material (CBM) having a thermoplastic matrix (preferably polyethylene) which is miscible with the thermoplastic material of the closure, and a plurality of microwave susceptor particles dispersed throughout the matrix. A strip is fashioned from the CBM and may be applied to the sealing edges of the closure. Upon application of microwave energy in an amount sufficient to heat the susceptors and cause both the CBM matrix and the adjacent portion of the closure to melt and flow together, a fusion bond is produced which seals the closure. If the closure is being used with a cable having an inner conductive layer or sheath, a second CBM may be used at this seal, having magnetically reactive susceptors.

Abstract: A semi-conductive, static-dissipative polymeric composite comprising an insulative polymeric resin, and from about 5 to about 60 volume percent of a particulate filler having thin-film, inorganic coatings of semi-conducting material, such composites having volume resistivities of from about 1.times.10.sup.4 --to about 1.times.10.sup.14 ohm-cm. In preferred semi-conductive, static-dissipative polymeric composites, the particulate filler has a thin-film coating of a semi-conducting material selected from the group consisting of transition metal oxides, carbides and nitrides.

Abstract: The invention concerns glass microbubbles having an inorganic thin-film coating not exceeding about 10 nm in thickness, especially a coating of a metal, a metalloid, or an alloy thereof. When dispersed throughout a matrix such as a polymer, the coated glass microbubbles can afford surprisingly good hiding power while also imparting esthetically pleasing colors to otherwise transparent articles.

Abstract: The invention primarily concerns a pressure-sensitive adhesive tape, the adhesive layer of which is filled with glass microbubbles and has a dark appearance by virtue of the microbubbles having a thin-film coating having an average thickness from 0.05 to 30 nm. A preferred thin-film coating is silver which can be applied by sputtering or by vapor deposition, preferably to an average thickness of between 1 and 10 nm.