Abstract: A composition is disclosed of a malonic acid derivative, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the malonic acid derivative in the coating forms particles in the gas stream which are detected by a monitor.

Abstract: A resinous composition, suitable for insulating electrical members, is made from a mixture containing about 100 parts of an epoxy resin, about 55 to 165 parts of an acid anhydride and about 0.04 to 0.5 parts of a quaternary organic arsonium compound acting as a latent catalyst.

Abstract: A composition is disclosed of a diazonium salt, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the diazonium salt in the coating forms particles in the gas stream which are detected by a monitor.

Abstract: A composition is disclosed of a metal acetylacetonate, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a gas stream. The solvent in the composition is evaporated to produce a thermoparticulating coating. When the electrical apparatus overheats the metal acetylacetonate in the coating forms particles in the gas stream which are detected by a monitor.

Abstract: A composition is disclosed of malonic acid, a resinous carrier, and a solvent. The composition is applied to a portion of an electrical apparatus which is exposed to a fluid stream. The solvent in the composition is evaporated to produce a thermo-particulating coating. When the electrical apparatus overheats the malonic acid in the coating forms particles in the fluid stream which are detected by a monitor.

Abstract: A flexible, nontacky prepreg for use in bonding high voltage coils and inner cooling channels which comprises a fibrous mat material containing a high molecular weight epoxy and a sterically hindered anhydride. The resin comprises approximately 25 to 500% by weight of the fibrous mat material.

Abstract: A thermoparticulating tape is disclosed which comprises a flexible fibrous material, a compound which thermoparticulates at a temperature below 200.degree.C dispersed throughout the flexible fibrous material, and a flexible outer coating over the flexible fibrous material through which the products formed when the compound thermoparticulates can pass. The tape is best made by dissolving the thermoparticulating compound in a solvent, immersing the fibrous material in the solution, evaporating the solvent, and applying the outer coating to the fibrous material. An adhesive backing can be applied to the tape if desired. The tape is placed in an electrical apparatus cooled by a gas stream, in a position exposed to the gas stream. When overheating occurs the tape darkens and emits particles into the gas stream which are detected by a monitor.

Abstract: A grease of a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether is used to protect electrical apparatus from overheating. The grease is applied to a portion of an electrical apparatus which is exposed to a gas stream, particularly to portions subjected to operating temperatures of about 100.degree. to about 130.degree.C. When the coated portion of the electrical apparatus overheats the grease forms particles in the gas stream which are detected by a monitor. The apparatus can then be shut down or its load reduced.

Abstract: A binding tape is made by coating a ribbon having glass fibers in the fill direction and a flexible, thermally stable fiber in the warp direction, with a swellable resin composition and removing the excess composition. The tape is lap-wound over an electrical conductor which is then immersed in solventless resin under pressure. The conductor is removed from the solventless resin and the tape prevents the solventless resin from seeping out before it is cured.