An insulated wire having an electrical wire structure capable of reducing an outer diameter while an insulating property and a flame-retardant property are highly kept is provided. In the insulated wire including: a conductor; and a coating layer arranged on an outer periphery of the conductor, the insulated wire has a flame-retardant property that allows the insulated wire to pass a vertical tray flame test (VTFT) on the basis of EN 50266-2-4, has a direct-current stability that allows the insulated wire to pass a direct-current stability test in conformity to EN 50305.6.7, has a diameter of the conductor that is equal to or smaller than 1.25 mm, and has a thickness of the coating layer that is smaller than 0.6 mm.

The present disclosure relates to insulation. Teachings thereof may be embodied in a solid insulation material, especially in tape form, the use thereof in a vacuum impregnation process and to an insulation system produced therewith, and also an electrical machine comprising the insulation system, especially for the medium- and high-voltage sector, namely for medium- and high-voltage machines, especially rotating electrical machines in the medium- and high-voltage sector, and to semifinished products for electrical switchgear. For example a solid insulation material with an anhydride-free impregnating agent may include: a carrier; a barrier material; a curing catalyst; and a tape adhesive. The curing catalyst and the tape adhesive are inert toward one another but react under the conditions of a vacuum impregnation process if combined with an anhydride-free impregnating agent having gelation times of 1 h to 15 h at impregnation temperature. The tape adhesive is free of oxirane groups and includes at least two free hydroxyl groups.

Provided are a core electric wire for multi-core cable that is superior in flex resistance at low temperature, and a multi-core cable employing the same. A core electric wire for multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer that covers an outer periphery of the conductor, in which, in a transverse cross section of the conductor, a percentage of an area occupied by void regions among the element wires is from 5% to 20%. An average area of the conductor in the transverse cross section is preferably from 1.0 mm.sup.2 to 3.0 mm.sup.2. An average diameter of the element wires in the conductor is preferably from 40 m to 100 m, and the number of the element wires is preferably from 196 to 2,450. The conductor is preferably obtained by twisting stranded element wires obtained by twisting subsets of element wires. The insulating layer preferably comprises as a principal component a copolymer of ethylene and an -olefin having a carbonyl group.

An insulated wire, having an electrical wire structure capable of reducing an outer diameter while maintaining an insulating property and a flame-retardant property, includes a conductor and a coating layer arranged on an outer periphery of the conductor. The coating layer includes a plurality of flame-retardant layers, each made of a flame-retardant resin composition, and an insulating layer interposed between the plurality of flame-retardant layers. A ratio of a thickness of the insulating layer to a thickness of the coating layer is equal to or larger than 10% and equal to or smaller than 35%.

A multilayer insulated wire includes a conductor, an inner insulation layer, and an outer insulation layer. A gel fraction of the inner insulation layer defined below is not less than 80%. A gel fraction of the outer insulation layer defined below is less than the gel fraction of the inner insulation layer and not less than 75%. An insulation covering layer including the inner and outer insulation layers is cross-linked and has a tensile modulus of not less than 500 MPa in a tensile test conducted at a tensile rate of 200 mm/min. Gel fraction (%)=(mass of inner or outer insulation layer after being immersed in xylene at 110 C. for 24 hours, then left at 20 C. and atmospheric pressure for 3 hours and vacuum-dried at 80 C. for 4 hours/mass of inner or outer insulation layer before immersion in xylene)100

An electrical steel sheet has an insulation coating on a steel sheet surface. The insulation coating includes: a binder consisting of 100 parts by mass of a metal phosphate and 1 to 50 parts by mass of an organic resin having an average particle size of 0.05 to 0.50 m; and a carboxylic acid-containing compound with a carbon number of 2 to 50 in an amount of 0.1 to 10.0 parts by mass based on 100 parts by mass of solids content of the binder. The organic resin is at least one selected from the group consisting of acrylic resins, epoxy resins, and polyester resins. The insulation coating of this electrical steel sheet shows good edge corrosion resistance after blanking.

Crosslinkable interpolymer blends comprising ethylene monomer residues, residues of comonomers having carboxylic acid and/or carboxylic acid anhydride functionality, and residues of comonomers having epoxide functionality, a peroxide initiator, and optionally a crosslinking catalyst, which, in embodiments, cure to a gel content of greater than (>) 50 wt % within less than 1.5 minutes at 200C, and require little or no degassing after crosslinking.

An insulated electric wire includes a conductor and an insulating layer covering an outer periphery of the conductor. The insulating layer is formed of a crosslinked polymer of an insulating resin composition that contains a resin component containing a first copolymer which is a copolymer of ethylene and an unsaturated hydrocarbon having 4 or more carbon atoms and which has a density of less than 0.88 g/cm.sup.3, a second copolymer which is a copolymer of ethylene and an unsaturated hydrocarbon having 4 or more carbon atoms and which has a density of 0.88 g/cm.sup.3 or more and less than 0.91 g/cm.sup.3, and a third copolymer which is a copolymer of ethylene and an acrylic acid ester or a copolymer of ethylene and a methacrylic acid ester, or containing the second copolymer and the third copolymer, in which a content of the second copolymer is 40% by mass or more of a total content of the first copolymer and the second copolymer and 60% by mass or less of a total content of the first copolymer, the second copolymer, and the third copolymer, and a ratio represented by the total content of the first copolymer and the second copolymer: a content of the third copolymer (mass ratio) is 80:20 to 40:60, and 30 to 100 parts by mass of a flame retardant and 1 to 5 parts by mass of a crosslinking assistant relative to 100 parts by mass of the resin component.

The present invention relates to a wire or cable comprising a conductor coated with an insulation composition, wherein said insulation composition comprises: i) a polyethylene copolymer having a melting point of 105 C. or less; and ii) a hindered amine light stabiliser (HALS) comprising at least one 2,2,6,6-tetramethyl-piperidinyl group present in an amount of 0.5 to 1.5 wt %.

The resin composition contains: a resin component containing an ethylene-(meth)acrylate ester copolymer and at least one of an ethylene-propylene-diene terpolymer or ethylene-acrylate rubber; and a flame retardant, and the resin component is crosslinked. The tensile stress at 19% strain of the resin composition is 2.0 MPa or less, and the resin composition has heat resistance at 150 C. prescribed in JASO D624.