JP2000030537A - Electric wires and cables - Google Patents

Abstract

[PROBLEMS] To provide an electric wire / cable having an outermost coating layer having excellent adhesiveness to a resin having a high polarity for insert injection molding and having excellent light weight, low cost, and excellent low temperature bending resistance. A wire / cable having an outermost coating layer, the outermost coating layer includes 40 to 95 parts by weight of a polyolefin having a crystal having a thermal softening point of 150 ° C. or more, and Shore D.
A crosslinking agent is used in an amount of 0.1 to 100 parts by weight of a blended polymer of 60 to 5 parts by weight of a soft polyolefin having a hardness of 65 or less.
One or both of a polyolefin having a crystal having a thermal softening point of 150 ° C. or higher and a soft polyolefin having a Shore D hardness of 65 or lower are formed of maleic anhydride. It is characterized by being denatured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric wires and cables. More specifically, the present invention relates to an electric wire or cable having an outermost coating layer having excellent adhesion to an injection molding resin.

[0002]

2. Description of the Related Art In general, materials for covering electric wires and cables are selected in consideration of electrical characteristics, mechanical characteristics, chemical characteristics, heat resistance, weather resistance, and the like.

On the other hand, in recent years, in addition to these characteristics, workability of electric wires and cables has been required.

For example, in the case of electric wires and cables used for applications such as resin injection molding at the terminal portion or the intermediate portion by insert injection molding or the like, it is required that the outermost coating layer has good adhesion to the injection molded resin. Is done. For example, terminals of electric wires and cables incorporated in precision electronic components such as rotation sensors of small vehicles and various types of vehicles such as automobiles and various vehicles are required to have sufficient airtightness so that moisture and the like do not enter from the outside. In the manufacture of such precision electronic components, a sensor outer or a cap for fixing a camera housing is molded directly by insert injection molding on a terminal portion or an outer periphery of an intermediate portion of the electric wire / cable.

[0005] By the way, as the resin for insert injection molding, a resin having a large polarity, for example, a polyamide resin, a polyester resin, a polycarbonate resin, an acrylic resin or the like is used. For this reason, the outermost coating material of the electric wire / cable is made of a resin having high polarity in consideration of adhesiveness, for example, a vinyl chloride resin admixture, a thermoplastic polyurethane elastomer (hereinafter, referred to as TPU), and a thermoplastic polyester elastomer (hereinafter, referred to as TPEE). Is used.

[0006]

[Problems to be solved by the invention]
The outermost coating material of the cable is vinyl chloride resin admixture, T
PU and TPEE have the following difficulties.

(1) Vinyl chloride resin admixture The vinyl chloride resin admixture has a high density. As a result, electric wires and cables formed by coating the vinyl chloride resin admixture are heavy and have a drawback that weight reduction is difficult. Further, the vinyl chloride resin mixture also has a disadvantage that the low-temperature bending resistance is poor. (2) TPU TPU is inferior in extrusion processability and high in price as compared with a vinyl chloride resin admixture.

(3) TPEE TPEE is also inferior in extrusion workability and expensive in comparison with a vinyl chloride resin admixture.

For these (1) to (3), lightness,
Examples of coating materials having low cost, low temperature bending resistance, and the like include polyolefin-based materials, such as polyethylene and polypropylene. However, polyolefin-based materials such as polyethylene and polypropylene are non-polar because they are essentially hydrocarbon-based polymers, and therefore have a problem in that they have poor adhesion to the resin for insert injection molding.

The present invention has been made in view of such a point, and an object of the present invention is to solve the above-mentioned drawbacks of the prior art, to have excellent adhesiveness to a resin having a large polarity for insert injection molding, and An object of the present invention is to provide an electric wire or cable having an outermost coating layer that is excellent in lightness, low cost, and low-temperature bending resistance.

[0011]

The gist of the present invention is to provide an electric wire or cable having an outermost coating layer.
The outermost coating layer is a crosslinking agent based on 40 to 95 parts by weight of a polyolefin having a crystal having a thermal softening point of 150 ° C. or more and 100 to 5 parts by weight of a blended polymer of 60 to 5 parts by weight of a soft polyolefin having a Shore D hardness of 65 or less. 0.1 to 1.1
Consisting of a composition in which the heat softening point is 1 part by weight.
One or both of a polyolefin having a crystal of 50 ° C. or higher and a soft polyolefin having a Shore D hardness of 65 or lower are modified with maleic anhydride.

Here, a polyolefin having a crystal having a heat softening point of 150 ° C. or higher improves the low-temperature bending resistance. Further, the polyolefin having a crystal having a thermal softening point of 150 ° C. or higher is partially decomposed by melt-kneading with a small amount of a compounded organic peroxide as a crosslinking agent, and the low-temperature bending resistance is further improved.

Further, one or both of a polyolefin having a crystal having a softening point of 150 ° C. or more and a soft polyolefin having a Shore D hardness of 65 or less are modified with maleic anhydride to obtain an insert injection molded resin. Improves adhesion with.

In the present invention, 100 to 100 parts by weight of a blended polymer of 40 to 95 parts by weight of a polyolefin having a crystal having a thermal softening point of 150 ° C. or more and 60 to 5 parts by weight of a soft polyolefin having a Shore D hardness of 65 or less is used. If the polyolefin having a crystal having a thermal softening point of 150 ° C. or higher is 95 or more, the low-temperature bending resistance is poor, and if it is 40 or less, the heat resistance is poor.

Further, the organic peroxide as a cross-linking agent is added in an amount of 0.1 to
The reason for using 1.1 parts by weight is that if it is 0.1 parts by weight or less, there is no effect of improving the low-temperature bending resistance, and if it is 1.1 parts by weight or more, excessive decomposition occurs.

In the present invention, the sheath layer is composed of the outermost coating layer and the inner sheath layer because the outermost coating layer contains a large amount of maleic anhydride-modified polyolefin, which is slightly more expensive than polyolefin. This is to prevent the cable from becoming expensive. That is, the inner sheath layer is a combination of inexpensive general polyolefin.

In this case, the inner sheath layer is formed of a polyolefin having a thermal softening point of 150 ° C. or higher.
Parts by weight and a blend polymer of 85 to 30 parts by weight of a soft polyolefin having a Shore D hardness of 65 or less is a polyolefin 70 having a crystal having a thermal softening point of 150 ° C. or more.
Above, the low-temperature bending resistance is inferior, and conversely, if it is less than 15, the heat resistance is inferior. Further, the amount of the organic peroxide as a crosslinking agent is set to 0.1.
The reason why the amount is set to 1 to 1.1 parts by weight is that when the amount is 0.1 parts by weight or less, there is no effect of improving the low-temperature bending resistance, and when the amount is 1.1 parts by weight or more, excessive decomposition occurs.

[0018]

Next, an embodiment of an electric wire / cable according to the present invention will be described.

In the present invention, the polyolefin having a crystal having a heat softening point of 150 ° C. or higher includes polypropylene, ethylene copolymerized polypropylene, poly-4-methyl-pentene-1 and the like.

In the present invention, the soft polyolefin having a Shore D hardness of 65 or less includes low density polyethylene,
Linear low-density polyethylene, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-anhydride Maleic acid copolymer,
Ethylene-butene 1 copolymer, ethylene-butene-hexene terpolymer, ethylene-propylene-diene terpolymer, styrene-ethylenebutylene-styrene terpolymer, styrene-ethylenebutylene binary copolymer Coalescing,
Styrene-ethylene propylene-styrene terpolymer, styrene-ethylene propylene binary copolymer, styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer, chlorinated polyethylene, chlorosulfonated polyethylene, liquid polyolefin rubber Etc. These may be used alone or as a blend of two or more.

In the present invention, the maleic acid-modified polyolefin having a crystal having a heat softening point of 150 ° C. or higher includes maleic acid-modified polypropylene, maleic acid-modified ethylene copolymerized polypropylene and the like.

Here, the maleic acid-modified polyolefin having a crystal having a heat softening point of 150 ° C. or higher is:
The polyolefin having a crystal having a thermal softening point of 150 ° C. or higher can be obtained by melt-kneading a small amount of maleic anhydride and an organic peroxide in polypropylene, ethylene copolymerized polypropylene, or the like.

In the present invention, the Shore A hardness is 20 to 9
As the maleic acid-modified polyolefin of 5, maleic acid-grafted low-density polyethylene, maleic acid-grafted linear low-density polyethylene, maleic acid-grafted ethylene-methyl acrylate copolymer, maleic acid-grafted ethylene-methyl methacrylate copolymer, Maleic acid-grafted ethylene-ethyl acrylate copolymer,
There are maleic acid-grafted ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer and the like.

Here, the Shore A hardness is 20 to 95.
The maleic acid-modified polyolefin is an ethylene-maleic anhydride copolymer to be copolymerized, excluding an ethylene-ethyl acrylate-maleic anhydride terpolymer.
It is obtained by melt-kneading a small amount of maleic anhydride and an organic peroxide into a soft polyolefin having a Shore D hardness of 65 or less.

In the present invention, examples of the peroxide crosslinking agent include hydroperoxide, diallyl peroxide, and diacyl peroxide. Specifically, dicrumyl peroxide, 1,3-bis- (tert-butylperoxyisopropyl) benzene, 2,5-di (ter
t-butylperoxy) hexane, 2,5-dimethyl-
2,5 (tert-butylperoxy) hexyne-3,
There are isopropyl cumyl and t-butyl peroxide. These can be used alone or in combination of two or more.

In the present invention, a flame retardant can be added to improve the flame retardancy.

The flame retardant includes a phosphorus compound, a hydrated metal compound, a metal oxide compound, a brominated flame retardant and a chlorine flame retardant. These flame retardants can be used alone or in combination of two or more.

Here, the phosphorus compound is red phosphorus,
Examples include phosphate esters, phosphonates, and phosphorinene.

Examples of the hydrated metal compound include magnesium hydroxide, aluminum hydroxide, hydrotalcite, calcium aluminate hydrate, calcium hydroxide, barium hydroxide, and hard clay.

As the metal oxide compound, antimony oxide;
Examples include aluminum oxide and magnesium oxide.

As the chlorine-based flame retardant, there is chlorinated paraffin and the like.

As the brominated flame retardant, there are ethylene tetrabromide, ethylene-bispentabromobenzene and the like.

The above-mentioned various compounding agents may be surface-treated with a fatty acid metal salt, an alkoxysilane, a titanate coupling agent, an acrylic resin or the like in accordance with a conventional method to improve water resistance.

In the resin composition of the present invention, an antioxidant, a lubricant, a surfactant, a coloring agent, a plasticizer,
Inorganic fillers, compatibilizers and the like can be blended.

In the present invention, the outermost layer of the electric wire / cable may be coated with an adhesion improver, for example, an adhesion primer or an adhesive, immediately before insert injection molding, or may be made of a maleic anhydride-modified polyolefin of about 100 μm. An extremely thin film may be formed in advance.

[0036]

Next, examples of the electric wires and cables according to the present invention will be described together with comparative examples.

The fluorine-containing elastomer wires and cables of the examples and the comparative examples were prepared as follows.

[Weighting and Sampling of Base Material]
The materials of Examples 1 to 8 and Comparative Examples 1 to 8 were weighed and collected according to the composition table of No. 3.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[Preparation of Pellet] Next, the base materials of Examples 1 to 8 and Comparative Examples 1 to 8 which were weighed and collected were kneaded at 190 ° C. by a 90 mm twin screw extruder to prepare a compound.

Next, these compounds were roll-kneaded at 50 to 60 ° C. with an open roll, and then pulled out into a sheet.

Next, these sheets were pelletized using a pelletizer to obtain pellets of Examples 1 to 8 and Comparative Examples 1 to 8.

[Preparation of Wire for Cable Core] A crosslinked polyethylene insulated wire having an outer diameter of 1.7 mm was prepared by coating a crosslinked polyethylene on a copper stranded conductor having an outer diameter of 0.35 mm to make a cable core.

[Preparation of Cable Core] First, a two-core cable core was prepared by twisting the above-prepared crosslinked polyethylene insulated wires with a two-stranding machine.

FIG. 5 is a sectional view of a <2-core cable core.

In FIG. 5, 1 is a copper stranded conductor, 2 is a cross-linked polyethylene insulating layer, and 4 is a cross-linked polyethylene insulated wire.

Next, a three-core cable core was prepared by twisting the three crosslinked polyethylene insulated wires prepared above, an inclusion, and a holding tape with a twisting machine.

FIG. 6 is a sectional view of a three-core cable core.

In FIG. 6, 1 is a copper stranded conductor, 2 is a cross-linked polyethylene insulating layer, 3 is an inclusion, 4 is a cross-linked polyethylene insulated wire, and 5 is a holding tape.

[Extrusion coating of cable] The extrusion coating of the cable is performed by extruding and coating the pelletized products of Examples 1 to 8 and Comparative examples 1 to 8 with an extruder. 8 single-layer sheathed cables were manufactured.

Further, by extruding and coating the inner sheath layer and then extruding and coating the pelletized product of Example 2 or Example 7, a double-layered sheath cable of Examples 9-1 is obtained.
6 cables were produced.

FIG. 1 shows a sectional head of the cable of the first embodiment.

FIG. 2 shows a sectional head of the cable of the seventh embodiment.

FIG. 3 shows a sectional head of the cable of the ninth embodiment.

1 to 3, 1 is a copper stranded conductor, 2 is a cross-linked polyethylene insulating layer, 3 is an inclusion, 4 is a cross-linked polyethylene insulated wire, 5 is a holding tape, 6 is an inner sheath layer,
7 is an outermost sheath layer.

[Cable Characteristics Test Method] Next, the cables of Examples 1 to 16 and Comparative Examples 1 to 8 obtained above were subjected to characteristic tests.

A. Heat welding, thermal deformation resistance First, wound densely cable 1m to metal rod having an outer diameter of 5 mm in diameter, it was degraded 10 days heat at 0.99 ° C..

After 10 days of thermal degradation, the cable was taken out to room temperature, then the cable was rewound, and then inspected for thermal welding between the cables and thermal deformation of the cables.

As a result, those having no thermal welding and thermal deformation were evaluated as “No”, and those having thermal welding and thermal deformation were evaluated as “Yes”.

B. Low temperature flexibility First, put the cable in a test chamber at -30 ° C., 3 kgf
Was applied.

Next, bending was repeated at a rate of 40 times / minute at 90 ° on each of the right and left sides (total 180 °) with a radius r = 15 mm, and the number of times until the wire was disconnected was obtained.

The results were displayed as follows.

；: 50,000 times or more Δ: 10,000 to 50,000 times ×; 10,000 times or less c. Hermeticity (with high polarity insert injection molding resin
Hermetic adhesion) First, a polyamide 66 was prepared 30 present what is insert injection molded into a cylindrical shape in the cable terminal portion.

FIG. 4 is an explanatory perspective view of an insert injection molded product.

In FIG. 4, 1 is a copper stranded conductor, 2 is a crosslinked polyethylene insulated layer, 4 is a crosslinked polyethylene insulated wire, 7
Is an outermost sheath layer, and 8 is an insert injection molded resin.

Next, these were subjected to [120 ° C. × 1 hour → −4
[0 ° C. × 1 hour] as one cycle, and 500 heat cycle tests were performed.

After 500 cycles, one end was immersed in water, and 3 kgf of high-pressure air was added from the other end.

As a result, a sample having no air bubbles was passed.
A sample in which even one bubble was generated was rejected.

[0071] d. Material costs were compared relatively.

○: low cost △: medium cost ×: high cost
e. The appearance was judged by visual observation of the cable appearance .

Good; good one bad; one with graininess, lack of smoothness, large variation in outer diameter, etc. f. Specific gravity (light weight) Measured by a standard method.

[Cable Characteristic Test Results] Cable characteristic test results are as shown in Tables 1 to 3 above.

As can be seen from Table 3, the cable of Comparative Example 1 suffers from heat fusion and thermal deformation, poor resistance to low-temperature bending, poor airtightness, and the highest specific gravity.

The cable of Comparative Example 2 has a disadvantage that the material cost is high.

The cable of Comparative Example 3 is disadvantageous in that it has heat fusion and thermal deformation and has a poor cable appearance.

The cable of Comparative Example 4 has a disadvantage that it has heat fusion and thermal deformation.

The cable of Comparative Example 5 is inferior in low-temperature bending resistance and high in material cost.

The cables of Comparative Examples 6 and 7 have a disadvantage that the low-temperature bending resistance is inferior.

The cable of Comparative Example 8 has a disadvantage that airtightness is poor.

On the other hand, as can be seen from Tables 1 and 2, the cables of Examples 1 to 16 are free from heat fusion and thermal deformation, have excellent low-temperature bending resistance, good airtightness, low material cost, It has a low specific gravity and is lightweight.

Although the cables have been described in these embodiments, the same results can be obtained with electric wires.

[0084]

The electric wires and cables of the present invention have an outermost coating layer which has excellent adhesiveness to a resin for insert injection molding having a large polarity, and is excellent in light weight, low cost and low temperature bending resistance. It is industrially useful as a wire for precision electronic parts of insert injection molding.

[Brief description of the drawings]

FIG. 1 shows a sectional head of a cable according to a first embodiment of the present invention.

FIG. 2 shows a sectional head of a cable according to a seventh embodiment of the present invention.

FIG. 3 shows a sectional head of a cable according to a ninth embodiment of the present invention.

FIG. 4 is an explanatory perspective view of an insert injection molded product.

FIG. 5 is a cross-sectional view of a two-core cable core.

FIG. 6 is a cross-sectional view of a three-core cable core.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper stranded wire conductor 2 Crosslinked polyethylene insulating layer 3 Inclusion 4 Crosslinked polyethylene insulated wire 5 Holding tape 6 Inner sheath layer 7 Outermost sheath layer 8 Insert injection molding resin

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 4J002 BB03X BB05X BB08X BB09X BB12W BB15W BB15X BB17W BB21W BB21X EK016 EK026 EK036 EK046 FD130 FD146 GQ01 5G305 AA02 AB34 BA12 BA05 CA07 CA07 CA02

Claims (4)

[Claims] 1. An electric wire or cable having an outermost coating layer, the outermost coating layer comprising 40 to 95 parts by weight of a polyolefin having a crystal having a thermal softening point of 150 ° C. or higher, and Shore D
0.1 to 100 parts by weight of a blending polymer of 60 to 5 parts by weight of a soft polyolefin having a hardness of 65 or less
One or both of a polyolefin having a crystal having a thermal softening point of 150 ° C. or more and a soft polyolefin having a Shore D hardness of 65 or less, comprising maleic anhydride. An electric wire or cable characterized by being modified with: 2. The polyolefin having a crystal having a thermal softening point of 150 ° C. or higher is one selected from polypropylene, ethylene copolymerized polypropylene and poly-4-methyl-pentene-1. The electric wire / cable according to claim 1. 3. A soft polyolefin having a Shore D hardness of 65 or less is low-density polyethylene, linear low-density polyethylene, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer. , Ethylene-vinyl acetate copolymer,
Selected from ethylene-glycidyl methacrylate copolymer, ethylene-maleic anhydride copolymer, ethylene-butene 1 copolymer, ethylene-butene-hexene terpolymer, and ethylene-propylene-diene terpolymer. The electric wire / cable according to claim 1, wherein the electric wire / cable is a selected one. 4. An electric wire or cable in which a sheath layer comprises an outermost coating layer and an inner sheath layer, wherein the outermost coating layer has a polyolefin having a thermal softening point of 150 ° C. or more.
A composition comprising 0 to 95 parts by weight and 0.1 to 1.1 parts by weight of a crosslinking agent with respect to 100 parts by weight of a blended polymer of 60 to 5 parts by weight of a soft polyolefin having a Shore D hardness of 65 or less; The thermal softening point is a polyolefin having a crystal of 150 ° C. or more, and the Shore D hardness is one or both of soft polyolefins having a hardness of 65 or less modified with maleic anhydride, and the inner sheath layer is A crosslinking agent is used in an amount of 0.1 to 1 part by weight based on 15 to 70 parts by weight of a polyolefin having a crystal having a thermal softening point of 150 ° C. or higher and 85 to 30 parts by weight of a blended polymer of 85 to 30 parts by weight of a soft polyolefin having a Shore D hardness of 65 or less. 1. An electric wire or cable comprising a composition in which 1 part by weight is blended.