JP3267327B2 - Solderable insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solderable insulated wire, and more particularly to a solderable insulated wire using a UV-crosslinked resin composition as a material for insulating coating.

[0002]

2. Description of the Related Art As a means for obtaining a thin-film electric wire, a method of applying and curing a liquid material is well known, and a typical example thereof is an enameled wire.

As the liquid material, there are a thermosetting type, an ultraviolet curing type, an electron beam curing type, and the like. Most of the enamel wires are made of a thermosetting material (thermosetting varnish). The thermosetting varnish includes epoxy, silicone, polyurethane, polyester, polyamidimide, polyimide, polyesterimide, and formal. Among these, it is known that an enameled wire using a urethane-based thermosetting varnish can be soldered as it is without peeling off a coating and without using a flux, as a feature not found in other enamels.

In recent years, with the miniaturization and weight reduction of computers, audios, automobiles, aircraft, artificial satellites, and the like, wires and cables used for them have been further reduced in diameter and thickness. One method is to reduce the thickness of the coating. In the thinning by the extrusion method, the thinner the coating, the more easily the strain caused by the temperature difference between the coating material and the conductor is apt to affect, and it is likely to cause a decrease in elongation. For this reason, the conductor is preheated. However, if the conductor becomes thinner, the strength decreases due to the heat of preheating, and furthermore, the wire may be disconnected due to the material pressure at the time of extrusion, which is not preferable.

Therefore, it would be very effective if a thermosetting material capable of reducing the film thickness could be used as a covering material for electric wires.
Need to be repeated more than once, many are 5
Excessive safety equipment is required due to the material occupied by 0% or more of the organic solvent, and coating is not as easy as polyethylene and polyvinyl chloride due to baking.
It is not preferable for coating of wiring wires or cables of electronic equipment and the like because of poor peelability.

[0006] At present, attention has been paid to a solvent-free, liquid ultraviolet-crosslinking resin composition which is used as a coating material for optical fibers, and is used as a coating material for an optical fiber, such as urethane acrylate, silicone acrylate, and fluorine acrylate. Such materials are used. These UV-crosslinkable resin compositions are used for radical polymerization, ionic polymerization, cationic polymerization, etc. utilizing ultraviolet rays (mainly radical polymerization).
It has the advantage that it is easy to thin coat because it is liquid and the curing speed is high and the productivity is high. In addition, it is higher in safety than thermosetting varnish, and can be obtained by one or several coatings to obtain an arbitrary film thickness. It also has the advantage that coloring is easier.

[0007]

However, according to the conventional insulated wire, since the soldering temperature of the ultraviolet-crosslinking resin composition as the coating material is extremely high, a thin conductor may be broken by heat. In addition, there is a disadvantage that the high temperature causes heat to be exerted on the substrate. In addition, there is a problem that resin residue (carbide) is easily left on the conductor, so that proper solderability is not obtained or no solder is attached.

It is therefore an object of the present invention together with the attained low temperature of soldering temperature is to provide a soldering insulated wire never carbides of the resin remains on the conductor.

[0009]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a functionalized photopolymerizable monomer to reduce the soldering temperature and to prevent the resin carbide from remaining on the conductor. Only a monomer whose group is a methacroyl group is used, and the monomer is contained in the resin composition in an amount of 15 wt% to 7 wt%.
An object of the present invention is to provide a solderable insulated wire in which a UV-crosslinked resin composition containing 0 wt% is applied as an insulating coating on the outer periphery of a conductor.

[0010] The ultraviolet crosslinked resin composition basically comprises a photopolymerizable oligomer, a photopolymerizable monomer, a photoinitiator and the like. Photopolymerizable oligomers include epoxy acrylates, epoxidized oil acrylates, urethane acrylates, polyester urethane acrylates, polyether urethane acrylates, unsaturated polyesters,
Polyester acrylates, polyether acrylates, vinyl / acrylates, polyenes / thiols, silicone acrylates, polybutadiene acrylates, polystilethyl acrylates, polycarbonate diacrylates, etc. An acryloyl group having a heavy bond (CH
₂ ＣＨCHCOO-) or a methacryloyl group (CH ₂ ＣC (C
H ₃₎ CO-), an allyl group _{(CH 2 = CHCH 2 -)} ,
A compound having two or more functional groups such as a vinyl group (CH ₂ ＣＨCH—), and a combination of a plurality of such compounds are preferable. Most preferred are urethane-based acrylate oligomers, particularly those whose functional groups are methacryloyl groups.

As the photopolymerizable monomer, it is necessary to use only a monomer whose functional group is a methacryloyl group. The content ratio of the monomer having a functional group of a methacryloyl group in the ultraviolet crosslinked resin composition is in a range of 15 wt% to 70 wt% . If the amount is less than 15% by weight, the solderability is remarkably reduced. If the amount is more than 70% by weight, the properties of the oligomer are impaired, and it is difficult to balance properties such as curability, mechanical properties and material viscosity. Further, it is better that the number of functional groups of the monomer per molecule is small, and if it is monofunctional, extremely excellent solderability can be provided.

The photoinitiator is not particularly limited. For example, known photoinitiators such as acetophenone, benzoin, benzophenone, and thioxanthone can be used. As acetophenones, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2
-Methyl-1- [4- (methylthio) phenyl] -2-
Morphopropane and the like, and benzophenones include benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether,
2,2-dimethoxy-2-phenylacetophenone and the like. Benzophenones include benzophenone, methyl benzoylbenzoate, 3,3'-dimethyl-
4-methoxybenzophenone and the like, and thioxanthone-based compounds such as 2.4-diethylthioxanthone and 2.4-
And dichlorothioxanthone.

Such an ultraviolet-crosslinkable resin composition may further contain, if necessary, a photoinitiator, an antiadhesive, a thixotrope, a filler, a plasticizer, a non-reactive polymer, a colorant, a flame retardant, Flame retardant aid, softening inhibitor, release agent, desiccant, dispersant,
Lubricants, anti-settling agents, thickeners, anti-static agents, anti-static agents, fungicides, rodents, termites, matting agents, anti-blocking agents, anti-skinning agents, etc. Compound,
Organic compounds can be used in combination.

[0014]

1 to 4 show a cross-sectional structure of an insulated wire to which the present invention is applied. The insulated wire in FIG. 1 is composed of a conductor 1 and an insulating coating 2 provided on the outer periphery thereof, and the insulated wire in FIG. 2 is constituted by a plurality of twisted conductors 1 and an insulating coating 2 provided on the outer periphery thereof. The insulated wire in FIG. 3 is composed of a plurality of conductors 1, an insulating coating 2 that individually covers the plurality of conductors 1, and a sheath 3 that covers them. The insulated wire in FIG. It comprises a plurality of twisted cores formed by twisting conductors 1, an insulating coating 2 for individually covering the twisted cores, and a sheath 3 for coating these.

In such an insulated wire, the present invention uses, as the insulating coating 2, an ultraviolet-crosslinked resin composition comprising a photopolymerizable oligomer , a photopolymerizable monomer , and a photoinitiator.
As the photopolymerizable monomer, <br/> monomer functional group is at methacryloyl group is used.

Hereinafter, embodiments of the insulated wire of the present invention will be described in detail. Using the compositions having the formulations shown in Table 1, nine types of insulated wires (Examples 1 to 7 and Comparative Examples 1 and 2) shown below were obtained.

[Table 1]

[0017]

Example 1 Urethane acrylate oligomer U-122
A (manufactured by Shin-Nakamura Chemical), 100 parts by weight of dicyclopentanyl methacrylate, and 2,2-photoinitiator
An ultraviolet-crosslinkable resin composition comprising 12.5 parts by weight of dimethoxy-2-phenylacetophenone was coated with a bare soft copper wire conductor 0.1.
3 (1 / 0.13) and cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 15 μm.

[0018]

Example 2 Urethane acrylate oligomer U-122
A100 parts by weight, dicyclopentanyl methacrylate 2
00 parts by weight and the photoinitiator 2,2-dimethoxy-2-
An ultraviolet-curable resin composition comprising 15 parts by weight of phenylacetophenone was coated with bare soft copper wire conductor 0.13 (1 / 0.13).
After coating on the top, it was cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 16 μm.

[0019]

Example 3 Urethane acrylate oligomer U-122
A (manufactured by Shin-Nakamura Chemical), 100 parts by weight of dicyclopentanyl methacrylate, and 2,2-photoinitiator
An ultraviolet-crosslinkable resin composition comprising 12.5 parts by weight of dimethoxy-2-phenylacetophenone was coated with a bare soft copper wire conductor 0.1.
3 (1 / 0.13), and then cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 16 μm.

[0020]

Example 4 Urethane methacrylate oligomer U-12
100 parts by weight of 2M (manufactured by Shin-Nakamura Chemical Co., Ltd.), 25 parts by weight of dicyclopentatyl methacrylate, and 2,2-
An ultraviolet-crosslinked resin composition comprising 5 parts by weight of dimethoxy-2-phenylacetophenone was added to a bare soft copper wire conductor 0.13 (1
/0.13), and then cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 16 μm.

[0021]

Example 5 Urethane acrylate oligomer U-122
A100 parts by weight, dicyclopentanyl methacrylate 8
0 parts by weight, 20 parts by weight of 1,6-hexadiol dimethacrylate (manufactured by Shin-Nakamura Chemical), and 2,2-
An ultraviolet-crosslinkable resin composition comprising 12.5 parts by weight of dimethoxy-2-phenylacetophenone was coated with a bare soft copper wire conductor 0.1.
3 (1 / 0.13) and cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 15 μm.

[0022]

Example 6 Urethane acrylate oligomer U-122
A100 parts by weight, dicyclopentanyl methacrylate 8
0 parts by weight, 20 parts by weight of trimethylolpropane trimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2,2-
An ultraviolet-crosslinkable resin composition comprising 12.5 parts by weight of dimethoxy-2-phenylacetophenone was coated with a bare soft copper wire conductor 0.1.
3 (1 / 0.13) and cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 15 μm.

[0023]

Example 7 Urethane acrylate oligomer U-122
A 100 parts by weight of A, 100 parts by weight of polyethylene glycol 90 methacrylate, and 12.5 parts by weight of a photoinitiator 2,2-dimethoxy-2-phenylacetophenone were mixed with a bare soft copper wire conductor 0.13 (1/1).
0.13) After coating on the top, it was cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 15 μm.

[0024]

Comparative Example 1 Urethane acrylate oligomer U-122
A 100 parts by weight of A, 50 parts by weight of dicyclopentanyl acrylate (manufactured by Hitachi Chemical), and 7.5 parts by weight of 2,2-dimethoxy-2-phenylacetophenone as a photoinitiator were exposed to a bare soft copper wire conductor. 0.13 (1 /
0.13) After coating on the top, it was cured through an ultraviolet irradiation furnace to obtain an insulated wire having an insulation thickness of 15 μm.

[0025]

Comparative Example 2 Urethane acrylate oligomer U-122
A100 parts by weight, dicyclopentanyl methacrylate 5
0 parts by weight, 50 parts by weight of dicyclopentanyl acrylate, and 10 parts by weight of 2,2-dimethoxy-2-phenylacetophenone as a photoinitiator were mixed with a bare soft copper wire conductor 0.13 (1/0). .13) After coating on top, it was cured by passing through an ultraviolet irradiation furnace, and the insulation thickness was 14 μm.
Insulated wire was obtained.

Next, the insulated wires of Examples 1 to 7 and the insulated wires of Comparative Examples 1 and 2 were evaluated for wire characteristics such as solderability, 20% elongation, and breakdown voltage.

As is clear from Table 1, the insulated wires of Examples 1 to 7 containing 15% or more of the methacryloyl group have good solderability, 20% elongation, and good values of breakdown voltage. ing. Moreover, in Example 1 and Example 3, Example 3 has better solderability at 360 ° C.
It can be seen that better solderability can be obtained when the functional group of the oligomer is a methacryloyl group. Further, Examples 1, 5,
6, it can be seen that the monofunctional monomer alone has better solderability at low temperature than the polyfunctional monomer. On the other hand, the insulated wires of Comparative Examples 1 and 2 use a monomer of an acryloyl group as a functional group, so that no solder is attached.
The solderability was low.

[0028]

As described in the foregoing, according to the solderability <br/> insulated wire of the present invention, an ultraviolet crosslinked resin composition a functional group containing more than 15 wt% of the monomer is methacryloyl group,
Since the insulating coating is provided on the outer periphery of the conductor, the soldering temperature can be reduced, and the resin carbide can be prevented from remaining on the conductor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an insulated wire.

FIG. 2 is a sectional view showing a configuration of an insulated wire.

FIG. 3 is a sectional view showing a configuration of an insulated wire.

FIG. 4 is a sectional view showing a configuration of an insulated wire.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Conductor 2 Insulation coating 3 Sheath

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Norio Takahata 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Power System Research Laboratories, Hitachi, Ltd. (56) References JP-A-1-97306 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 7/02 C09D 5/25 H01B 3/22

Claims (2)

(57) [Claims] 1. An insulated wire in which an insulating coating is applied to the outer periphery of a conductor, wherein the insulating coating is made of a UV-crosslinked resin composition containing a photopolymerizable oligomer, a photopolymerizable monomer, and a photoinitiator. As the polymerizable monomer, only a monomer whose functional group is a methacryloyl group is used, and the content ratio of the monomer in the ultraviolet-crosslinked resin composition is 15 wt%.
A solderable insulated wire characterized in that the content is up to 70 wt% . 2. The solderable insulated wire according to claim 1, wherein the monomer is monofunctional.