Sumitomo Electric Industries, Limited

Yuhei Mayama

Shinya Nishikawa

Takaya Kohori

Shigeyuki Tanaka

Hiroyuki Okawa

Takayuki Hirai

Hiroshi Hayami

Yuji Ochi

Satoshi Hashimoto

Takami Sagisaka

An electric wire for use in an electric vehicle with a large current of 100 A or more and a high voltage of 30 V or more includes a conductor and an electrically insulating layer covering an outer surface of the conductor, wherein the conductor includes first twisted wires in each of which a plurality of element wires are twisted together, and the first twisted wires are twisted together to form one or more second twisted wires, wherein an element-wire diameter of each of the element wires is 0.18 mm to 0.35 mm, and wherein a secant modulus of the electrically insulating layer is 15 MPa to 41 MPa.

Thick electric wire

An object of the present disclosure is to provide a core electric wire for a 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 a multi-core cable according to an aspect of the present disclosure comprises a conductor obtained by twisting element wires, and an insulating layer covering the conductor, wherein a linear expansion coefficient C of the insulating layer at from 25&#xb0; C. to &#x2212;35&#xb0; C. is no less than 1&#xd7;10Kand no greater than 2.5&#xd7;10K.

Core electric wire for multi-core cable and multi-core cable

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 mmto 3.0 mm. An average diameter of the element wires in the conductor is preferably from 40 &#x3bc;m to 100 &#x3bc;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 &#x3b1;-olefin having a carbonyl group.

A cable includes at least one core that has a conductor and an insulating coating layer that covers the conductor; and a sheath layer that covers the at least one core. The sheath layer includes an inner sheath layer and an outer sheath layer that covers the inner sheath layer. The inner sheath layer contains a silane-crosslinked very low density polyethylene. A main component of the outer sheath layer is polyurethane; a content of the very low density polyethylene per 100 parts by mass of a resin component in the inner sheath layer is 20 parts by mass or more and 100 parts by mass or less. A content of silicon atoms constituting silane crosslinks in the very low density polyethylene is 0.05 mass % or more and 1 mass % or less.

Cable

A core electric wire for a multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer covering the conductor, a principal component of the insulating layer being a copolymer of ethylene and an &#x3b1;-olefin having a carbonyl group; the &#x3b1;-olefin content in the copolymer being 14% to 46% by mass; and a mathematical product C*E being 0.01 to 0.9, wherein C is a linear expansion coefficient of the insulating layer at from 25&#xb0; C. to &#x2212;35&#xb0; C., and E is a modulus of elasticity thereof at &#x2212;35&#xb0; C. Average area of the conductor in the transverse cross section is 1.0 to 3.0 mm. Average diameter of the element wires in the conductor is 40 to 100 &#x3bc;m, and number of the element wires is 196 to 2,450.

The electric wire according to one aspect of the present invention is an electric wire comprising an insulated electric wire and one or more coating layers covering the insulated electric wire, wherein at least one layer of the one or more coating layers is formed from a resin composition containing a thermoplastic polyurethane elastomer and an allophanate crosslinking agent. The electric wire having such a characteristic feature is excellent in abrasion resistance and heat resistance and can be produced at low costs.

Electric wire and method for producing the same, and multi-core cable and method for producing the same

A core electric wire for a multi-core cable according to an aspect of the present invention comprises a conductor obtained by twisting element wires, and an insulating layer covering the conductor, a principal component of the insulating layer being a copolymer of ethylene and an &#x3b1;-olefin having a carbonyl group; the &#x3b1;-olefin content in the copolymer being 14% to 46% by mass; and a mathematical product C*E being 0.01 to 0.9, wherein C is a linear expansion coefficient of the insulating layer at from 25&#xb0; C. to &#x2212;35&#xb0; C., and E is a modulus of elasticity thereof at &#x2212;35&#xb0; C. Average area of the conductor in the transverse cross section is 1.0 to 3.0 mm. Average diameter of the element wires in the conductor is 40 to 100 &#x3bc;m, and number of the element wires is 196 and 2,450.

An insulated electrical wire that includes a conductor and an insulating layer covering a circumferential surface of the conductor, in which the insulating layer is composed of a resin composition that contains poly(4-methyl-1-pentene) as a main component and a melt mass flow rate of the poly(4-methyl-1-pentene) measured at a temperature of 300&#xb0; C. and a load of 5 kg according to the 1999 edition of JIS-K 7210 is 50 g/10 min or more and 80 g/10 min or less.

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Kanuma, Japan

Yuhei Mayama