In an aspect, a dielectric composite comprises a thermoset epoxy resin; a reinforcing layer; greater than or equal 40 volume percent of a hexagonal boron nitride based on the total volume of the dielectric composite minus the reinforcing layer; 3 to 7.5 volume percent of a fused silica based on the total volume of the dielectric composite minus the reinforcing layer; an epoxy silane; an accelerator; and a de-aerator. The hexagonal boron nitride can comprise a plurality of hexagonal boron nitride platelets and a plurality of hexagonal boron nitride agglomerates. A volume ratio of the hexagonal boron nitride agglomerates to the hexagonal boron nitride platelets can be 1:1.5 to 4:1.

In an aspect, a dielectric composite comprises a thermoset epoxy resin; a reinforcing layer; greater than or equal 40 volume percent of a hexagonal boron nitride based on the total volume of the dielectric composite minus the reinforcing layer; 3 to 7.5 volume percent of a fused silica based on the total volume of the dielectric composite minus the reinforcing layer; an epoxy silane; an accelerator; and a de-aerator. The hexagonal boron nitride can comprise a plurality of hexagonal boron nitride platelets and a plurality of hexagonal boron nitride agglomerates. A volume ratio of the hexagonal boron nitride agglomerates to the hexagonal boron nitride platelets can be 1:1.5 to 4:1.

A sealing composition and a sealing method for a coated electric cable have excellent sealing performance even under conditions such as cooling-heating cycles or high temperature and humidity. The coated electric cable sealing composition is for sealing a core wires connection section formed by electrically connecting multiple core wires exposed from multiple coated electric wires, and features having a hardening time of 10 minutes or less at 130° C., and permeating to inside of the coated electric wires at a height of 5 mm or more at the time point of hardening while the exposed parts of the core wires including the core wires connection section and the boundary part between the coated parts and the exposed parts of the core wires are immersed perpendicularly in the coated electric cable sealing composition filled in a resin cap and the sealing composition is heated to be cured.

A sealing composition and a sealing method for a coated electric cable have excellent sealing performance even under conditions such as cooling-heating cycles or high temperature and humidity. The coated electric cable sealing composition is for sealing a core wires connection section formed by electrically connecting multiple core wires exposed from multiple coated electric wires, and features having a hardening time of 10 minutes or less at 130° C., and permeating to inside of the coated electric wires at a height of 5 mm or more at the time point of hardening while the exposed parts of the core wires including the core wires connection section and the boundary part between the coated parts and the exposed parts of the core wires are immersed perpendicularly in the coated electric cable sealing composition filled in a resin cap and the sealing composition is heated to be cured.

An insulating composition having a polymer resin, a nanoclay, and one or more nanofillers. The insulating composition has a thermal conductivity of greater than about 0.8 W/mK, a dielectric constant of less than about 5, a dissipation factor of less than about 3%, and a breakdown strength of greater than about 1,000V/mil. The insulating composition has an endurance life of at least 400 hours at 310 volts per mil.

An electrical insulation sheet comprising a resin composition layer, wherein one surface side has a higher relative permittivity at a frequency of 1 MHz than the relative permittivity of an other surface side, and a circuit pattern is formed on the one surface side, a laminated body comprising the electrical insulation sheet and a metal plate on a metal base plate in that order, wherein a circuit pattern is formed on the metal plate, and a substrate comprising the electrical insulation sheet and a metal plate on a metal base plate in that order, wherein the metal plate has a circuit pattern.

A multiple component anhydride-free, thermosetting epoxy resin composition comprising, (A) at least one epoxy resin, and (B) at least one curing agent selected from the group of (b1) a polyetheramine of the formula (1) (Formula (1)), wherein x is a number of from 2 to 8, and (b2) a polyetheramine with at least one terminal end group of the formula (2) (Formula (2)), and (C) at least one epoxy silane, is, in particular, suitable for the manufacture of instrument transformers and dry-type transformers by casting, potting and encapsulation processes, wherein said articles exhibit good mechanical, electrical and dielectrical properties. ##STR00001##

The present invention provides a powder coating composition capable of forming a uniform coating film being superior in edge cover property and superior in insulation property. In addition, by a method for forming a coating film in which the coating composition according to the present invention is used, heating can be performed at low temperature. The powder coating composition comprises a bisphenol A type epoxy resin (A), a phenolic curing agent (B), and a curing accelerator (C) as coating film forming components.

The present invention provides a powder coating composition capable of forming a uniform coating film being superior in edge cover property and superior in insulation property. In addition, by a method for forming a coating film in which the coating composition according to the present invention is used, heating can be performed at low temperature. The powder coating composition comprises a bisphenol A type epoxy resin (A), a phenolic curing agent (B), and a curing accelerator (C) as coating film forming components.

A resin producing method is a method of producing a resin with which an insulating structure formed on an outer peripheral portion of a conductor is impregnated, the method including: a filler mixing step of mixing a nanofiller at a ratio of 15 wt % or more with an epoxy resin to form a mixture; a shear mixing step of causing the mixture to be subjected to shear mixing; a diluent mixing step of mixing a reactive diluent that reduces a viscosity of the epoxy resin, with the mixture after the shear mixing step; and a curing agent mixing step of mixing an acid anhydride curing agent with the mixture after the diluent mixing step.