Hitachi Metals, Ltd.

Hitachi Cable, Inc.

Shuta Nabeshima

Hideyuki Kikuchi

Yuki Honda

Takami Ushiwata

Tomiya Abe

Yasuhiro Funayama

Hidehito Hanawa

An insulated wire includes a conductor and an insulating layer formed on an outer periphery of the conductor, and the insulating layer is composed essentially of a polyimide resin having a repeating unit A represented by Formula (1) as a part of a molecular structure, in which a water absorption coefficient is not greater than 2.8% after 24 hours under condition at temperature of 40&#xb0; C. and humidity of 95%. 

Insulated wire and coil using same

An insulated wire includes a conductor, and a polyimide insulation layer formed on an outer periphery of the conductor. The insulation layer includes a polyimide including a repeating unit represented by formula (1) and a repeating unit represented by formula (2). A first acid component in the repeating unit represented by the formula (1) and a second acid component in the repeating unit represented by the formula (2) are mixed in a molar ratio range of 85:15 to 40:60 as expressed by a molar ratio (the first acid component:the second acid component). R as a residue of a diamine component in the formulas (1) and (2) includes a residue of 4,4'-diaminodiphenyl ether and a residue of one selected from a group of diamines represented by the formulas (3) to (8). A storage elastic modulus of the polyimide at 325&#xb0; C. is not less than 50 MPa.

Insulated wire and coil using the same

An insulated electric wire includes a rectangular conductor and an insulation film disposed on the periphery of the rectangular conductor. The insulation film is characterized by: the provision of a resin containing an imide structure within a molecule; and a peak value of less than 1.0 for the loss tangent tan &#x3b4;, which is represented by the ratio between the loss elastic modulus and the storage elastic modulus, as measured in the 50 DEG C. to 400 DEG C. range.

Insulated electric wire and coil

An insulated electric wire includes a conductor and an insulating coating provided around a perimeter of the conductor. The insulating coating includes a first insulating coating film around the perimeter of the conductor, the first insulating coating film being formed of a resin containing an imide structure in its molecule, and a second insulating coating film around a perimeter of the first insulating coating film, the second insulating coating film being formed of a polyimide resin comprising a repeat unit represented by Formula 1, and having an imide concentration of not less than 15% and not more than 36%, 

Insulated electric wire and coil using same

An insulated wire includes a conductor, and an insulating covering layer including a first insulation layer formed around the conductor and a second insulation layer formed around the first insulation layer. An elastic modulus of the second insulation layer at 300&#xb0; C. is not less than 300 MPa, and a relative permittivity of the insulating covering layer is not more than 3.0.

Insulated wire and coil

A insulated wire includes a conductor, and an insulating coating on a periphery of the conductor. The insulating coating includes an insulating film formed by applying and baking a polyester imide resin insulating coating material, and the insulating film has a relative permittivity of less than 3.5 both in a dried state and in a moisture-absorbed state. The insulating film is formed by applying and baking a polyester imide resin insulating coating material including an imide dicarboxylic acid and an alcohol component, the imide dicarboxylic acid being obtained by synthesizing a diamine component including aromatic diamine having not less than three aromatic rings and an acid component including aromatic tricarboxylic acid anhydride.

Polyester imide resin insulating coating material, insulated wire using same, and coil

An insulating varnish includes a polyamide-imide resin including a repeat unit represented by Formula (1) below derived from a synthesis reaction between a resin component (X) and a diisocyanate component (Y). The resin component (X) is derived from a synthesis reaction between a diamine component including aromatic diamines including g a divalent aromatic group (R) including three or more aromatic rings, and an acid component in the presence of an azeotrope solvent. The diisocyanate component (Y) includes a 2,4'-diphenylmethane diisocyanate (Y) and a 4,4&#x2032;-diphenylmethane diisocyanate (Y). In Formula (1), R denotes the divalent aromatic group including three or more aromatic rings, and m and n denote an integer of from 1 to 99.

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Hitachi, Japan

Shuta Nabeshima