Electrical wire, coaxial electrical wire, cable, and method for manufacturing electrical wire

Patent metadata

Field	Value
Publication number	US-2020161018-A1
Application number	US-201916678892-A
Country	US
Kind code	A1
Filing date	Nov 8, 2019
Priority date	Nov 20, 2018
Publication date	May 21, 2020
Grant date	—

Abstract

An electrical wire includes a metal conductor and an insulation layer. A wire diameter of the metal conductor is 0.20 mm or smaller. The insulation layer covers the metal conductor. The insulation layer includes an ultraviolet-crosslinkable resin composition containing 80% by mass or more of a thermoplastic resin. The ultraviolet-crosslinkable resin composition desirably contains, relative to 100 parts by mass of the thermoplastic resin, 0.5 parts by mass or more and 5 parts by mass or less of a photoradical generator, and 1 part by mass or more and 15 parts by mass or less of a reactive monomer.

First claim

1 . An electrical wire comprising:
a metal conductor with a wire diameter of 0.20 mm or smaller; and an insulation layer covering the metal conductor, wherein the insulation layer comprises an ultraviolet (UV)-crosslinkable resin composition containing 80% by mass or more of a thermoplastic resin.

2 . The electrical wire according to claim 1 ,
wherein the UV-crosslinkable resin composition comprises, relative to 100 parts by mass of the thermoplastic resin:
0.5 parts by mass or more and 5 parts by mass or less of a photoradical generator; and
1 part by mass or more and 15 parts by mass or less of a reactive monomer.

3 . A coaxial electrical wire comprising:
an electrical wire according to claim 1 ; external conductors disposed on an outer circumference side of the insulation layer; and a sheath layer disposed on an outer circumference side of the external conductors.

4 . A cable comprising:
at least one electrical wire comprising a metal conductor with a wire diameter of 0.20 mm or smaller; and an insulation layer covering the metal conductor, wherein the insulation layer comprises an ultraviolet (UV)-crosslinkable resin composition containing 80 by mass or more of a thermoplastic resin, and/or at least one coaxial electrical wire according to claim 3 ; and a sheath comprising a thermoplastic resin, a flame retardant, and an additive, the sheath binding the at least one electrical wire and/or the at least one coaxial electrical wire.

5 . A method for manufacturing an electrical wire comprising:
coating, using extrusion coating, a metal conductor having a wire diameter of 0.20 mm or smaller with an ultraviolet (UV)-crosslinkable resin composition comprising 80% by mass or more of a thermoplastic resin; and UV irradiating the UV-crosslinkable resin composition while temperature of the UV-crosslinkable resin composition is at a melting point or higher.

6 . The method for manufacturing an electrical wire according to claim 5 ,
wherein the UV irradiating is performed by a metal halide lamp or an UV light emitting diode (LED).

7 . The method for manufacturing an electrical wire according to claim 6 ,
wherein the UV irradiating is performed by the UV LED comprising various types of UV LEDs with different emission wavelengths.

8 . The method for manufacturing an electrical wire according to claim 5 , the method further comprising:
heating the UV-crosslinkable resin composition is performed before the UV irradiation and/or after the UV irradiation.

9 . The method for manufacturing an electrical wire according to claim 5 ,
wherein a melt flow rate of the UV-crosslinkable resin composition while the extrusion coating is performed at 190° C. is 4 or more.

10 . A method for manufacturing an electrical wire, the method comprising:
feed a metal conductor from a feeder to a molding device; extrude, using the molding device, an insulating layer onto the metal conductor, wherein the extruded insulating layer is an ultraviolet (UV) crosslinkable resin composition including:
a thermoplastic resin,
a reactive monomer, and
a photoradical generator,
heat, in a first heater, the extruded insulating layer; UV irradiate the heated extruded insulating layer, such that the heated extruded insulating layer is partially crosslinked; further heat, in a second heater, the partially crosslinked insulating layer, such that additional crosslinking occurs; and cool the additionally crosslinked insulating layer.

11 . The method of claim 10 , further comprising:
reel the electrical wire, including the cooled additionally crosslinked insulating layer, into a reel device.

12 . The method of claim 11 ,
wherein the molding device includes:
a driving device;
a resin feed aperture;
a cylinder in communication with the resin feed aperture;
a screw located substantially in the cylinder; and
a molding head.

13 . The method of claim 12 ,
wherein a diameter of the metal conductor is not more than 0.2 mm, and wherein the UV crosslinkable resin composition includes:
the thermoplastic resin, in a first proportion of at least 80% by weight, based on a weight of the UV crosslinkable resin composition;
the reactive monomer, in a second proportion of at least 1% and not more than 30% by weight, based on a weight of the thermoplastic resin; and
a photoradical generator, in a third proportion of at least 0.5% and not more than 10% by weight, based on the weight of the thermoplastic resin.

14 . The method of claim 13 ,
wherein the reactive monomer is further in a preferred reactive monomer range of at least 1% and not more than 15% by weight, based on the weight of the thermoplastic resin.

15 . The method of claim 14 ,
wherein the photoradical generator is further in a preferred photoradical generator range at least 0.5% and not more than 5% by weight, based on the weight of the thermoplastic resin.

16 . The method of claim 15 , wherein:
the reactive monomer is triallyl isocyanurate (TAIC); the reactive monomer is approximately 4% by weight, based on the weight of the thermoplastic resin; the photoradical generator is approximately 2% by weight, based on the weight of the thermoplastic resin; and the UV crosslinkable resin composition further includes:
substantially no organic peroxide (DCP),
a phenolic antioxidant of approximately 1% by weight, based on the weight of the thermoplastic resin, and
a phosphorus antioxidant of approximately 1% by weight, based on the weight of the thermoplastic resin.

17 . The method of claim 16 , wherein:
an extrusion temperature in the molding device is approximately 210 degrees Celsius; a melt flow rate (MFR) of the UV crosslinkable resin composition is approximately 9 grams/10 minutes at 190 degrees Celsius; and
a degree of crosslinking based on xylene extraction at 110 degrees Celsius for 24 hours is approximately 82%.

Assignees

• Hitachi Metals Ltd

Inventors

• Suzuki Hideyuki
• Oriuchi Takuya
• Iikai Katsuya

Classifications

• C08K5/56

  Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond · CPC title

• H01B11/18

  Coaxial cables; Analogous cables having more than one inner conductor within a common outer conductor · CPC title

• H01B13/14

  by extrusion {(extrusion in general B29C48/00)} · CPC title

• H01B7/0216

  Two layers · CPC title

• C08J2323/06

  Polyethene · CPC title