JP2001226536A - Olefinic resin composition and covered electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a halogen-free olefinic resin composition which satisfies well balanced properties between the wear resistance, flame retardancy, tensile characteristics and flexibility which are required for a covering material on automobile electric wires. SOLUTION: The olefinic resin composition comprises 20-70 pts.wt. of (a) a polyolefin resin; 5-60 pts.wt. of (b) an olefinic copolymer resin of an olefin and 0.1-20 wt.% of an epoxy group-containing comonomer; 5-60 pts.wt. of (c) a polymer component of at least one kind selected from the group consisting of (c1) a styrenic elastomer, (c2) a styrenic elastomer modified with 0.1-20 wt.% of an acid anhydride and (c3) a polyolefin modified with 0.1-20 wt.% of an acid anhydride (wherein, the sum total of components (a), (b) and (c) is 100 pts.wt.); and (d) 30-200 pts.wt. of a metal hydroxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin resin composition and a coated electric wire, and more particularly, to a material such as abrasion resistance, flame retardancy, tensile properties and flexibility required for a coating material of an electric wire for an automobile. The present invention relates to a halogen-free olefin-based resin composition that satisfies the characteristics, and an electric wire coated with such a halogen-free olefin-based resin composition.

[0002]

2. Description of the Related Art Polyvinyl chloride has been mainly used as a material for covering electric wires for automobiles. that is,
This is because polyvinyl chloride was excellent in mechanical strength, wire extrusion processability, flexibility, coloring properties, and economic efficiency. However, in consideration of recent global environmental measures, halogen-free resin materials have been used instead of polyvinyl chloride in the manufacture of automotive parts, including the coating of automotive electric wires.

[0003] As an abrasion-resistant resin composition having the advantage that no toxic gas such as halogen gas is generated during combustion, a halogen-free resin composition comprising a polyolefin base polymer and a metal hydroxide as a flame retardant is known. (JP-A-7-176219, JP-A-7-176219)
No. 78518). However, in order to make the disclosed resin composition flame-retardant to the extent that it has self-extinguishing properties, it is necessary to add a large amount of metal hydroxide. This causes a problem that the mechanical strength such as abrasion resistance and tensile strength is extremely reduced.
In order to avoid a decrease in mechanical strength, it is conceivable to increase the amount of relatively hard polypropylene or high-density polyethylene, but doing so impairs the flexibility of the insulated wire,
Workability also worsens.

[0004]

SUMMARY OF THE INVENTION The present invention provides a halogen-free olefin resin which satisfies well-balanced properties such as abrasion resistance, flame retardancy, tensile properties and flexibility required for a coating material of an electric wire for an automobile. It is intended to provide a composition.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides (a) 20 to 70 parts by weight of a polyolefin resin, and (b) 0.1 to 20% by weight of an epoxy group-containing comonomer and an olefin. Olefin copolymer resin 5-6
0 parts by weight, and (c) (c1) a styrene-based elastomer, (c2) a styrene-based elastomer modified with 0.1 to 20% by weight of an acid anhydride, and (c3) 0.1 to
5 to 60 parts by weight of at least one polymer component selected from the group consisting of polyolefins modified with 20% by weight of acid anhydride (provided that the total of components (a), (b) and (c) is 100 parts by weight) and (c)
An olefin-based resin composition comprising 30 to 200 parts by weight of a metal hydroxide is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each component contained in the composition of the present invention will be described. The type of the polyolefin resin (a) contained in the composition of the present invention is not particularly limited, and may be an olefin homopolymer (eg, polyethylene, polypropylene, polybutene, etc.), an olefin copolymer (eg, ethylene-propylene copolymer, ethylene-butene copolymer). Olefins and other monomers (eg, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA)) , Ethylene-
Methyl methacrylate copolymer) can be used. These can be used alone or as a mixture (blend) of two or more. Among them, polypropylene, polypropylene / EVA blend, polypropylene / EEA blend, polypropylene / ethylene-propylene rubber blend and the like are preferable.

The proportion of the polyolefin resin (a) is from 20 to 7 in 100 parts by weight of the total of the polymer components (a) to (c).
0 parts by weight, preferably 30 to 60 parts by weight. When the proportion of the polyolefin resin (a) is less than the above lower limit, the abrasion resistance of the composition decreases.

[0008] The olefin copolymer resin (b) contains 0.1%
It is a copolymer of 1 to 20% by weight of an epoxy group-containing comonomer and an olefin. As the epoxy group-containing comonomer, a known unsaturated compound having a glycidyl group, for example, glycidyl methacrylate can be used. Examples of the olefin include an olefin having 1 to 6 carbon atoms, specifically, ethylene, propylene, butene, and the like. Along with these olefins, other polymerizable monomers such as vinyl acetate, acrylate or methacrylate (eg, ethyl acrylate, methyl acrylate copolymer, methyl methacrylate, etc.) may be copolymerized.

The proportion of the epoxy group-containing comonomer in the copolymer resin (b) is 0.1 to 2 with respect to the total weight of the copolymer.
0% by weight, preferably 5 to 20% by weight. If the proportion of the epoxy group-containing comonomer in the copolymer is less than the above lower limit, the abrasion resistance of the resin composition will not be improved.

The proportion of the olefin copolymer resin (b) in the composition is 10% in total of the polymer components (a) to (c).
5 to 60 parts by weight, preferably 10 to 50 parts by weight in 0 parts by weight
Parts by weight. When the proportion of the olefin copolymer resin (b) exceeds the above upper limit, the abrasion resistance of the composition decreases. On the other hand, when the proportion of the olefin copolymer resin (b) is less than the above lower limit, the composition becomes Flexibility is impaired and processing becomes difficult.

The styrene elastomer (c1) is preferably a polymer obtained by block copolymerizing styrene and butadiene, or styrene, ethylene and propylene, and saturating the double bond of the obtained block copolymer by hydrogenation.

[0012] Acid anhydride modified styrene elastomer (c
2) is a styrene-based elastomer as described above,
Modified with 10 to 10% by weight of a carboxylic anhydride (for example, maleic anhydride or the like).

The polyolefin (c3) modified with an acid anhydride is a polyolefin modified with 0.1 to 10% by weight of a carboxylic anhydride (for example, maleic anhydride, etc.), for example, polyethylene, polypropylene, polybutene, ethylene. -Vinyl acetate copolymer (EVA),
Ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer, ethylene-propylene rubber, ethylene-butene copolymer and the like. Among them,
Polypropylene modified with maleic anhydride is preferred.

The proportion of the polymer component (c) is 5 to 60 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the total of the polymer components (a) to (c). When the proportion of the polymer component (c) exceeds the above upper limit, the abrasion characteristics are impaired. On the other hand, when the proportion of the polymer component (c) is less than the above lower limit, flexibility is impaired and processability is deteriorated.

Examples of the metal hydroxide (d) include magnesium hydroxide and aluminum hydroxide. Particles of the metal hydroxide are usually a coupling agent, especially a silane coupling agent (for example, an aminosilane coupling agent,
It is preferable that the surface is treated with a surface treating agent such as a vinyl silane coupling agent, an epoxy silane coupling agent, or a higher fatty acid (eg, stearic acid, oleic acid, etc.). Among them, magnesium hydroxide surface-treated with an aminosilane coupling agent is particularly preferable.

The ratio of the metal hydroxide to the total amount (100 parts by weight) of the polymers (a) and (b) in the composition is usually 30 to 200 parts by weight, preferably 50 to 150 parts by weight.
Parts by weight. If the proportion of the metal hydroxide is too large, the elongation of the composition is deteriorated, and the wear resistance, flexibility and workability are also impaired. On the other hand, if the proportion of the metal hydroxide is too small, the flame retardancy of the composition becomes poor.

To the olefin resin composition of the present invention, a compounding agent usually added to the olefin resin, for example, an antioxidant, a copper damage inhibitor, a lubricant or the like is added in an amount which does not deteriorate the above-mentioned properties. You may. Further, as a flame retardant aid, zinc borate, a phosphorus-based flame retardant, calcium carbonate, and the like can be appropriately added. The olefin-based resin composition of the present invention can be prepared by mixing and kneading the above-mentioned components by a usual method. Further, the composition of the present invention may be crosslinked by a conventional crosslinking method, for example, electron beam crosslinking, chemical crosslinking, water crosslinking and the like. The method of coating an electric wire, particularly an electric wire for automobiles, with the resin composition of the present invention,
It is the same as the conventional method.

When the olefin resin composition of the present invention is used as a coating material for automobile electric wires, the olefin resin composition satisfies characteristics such as abrasion resistance, flame retardancy, tensile properties and flexibility required for the coating material. And an excellent halogen-free resin composition. In particular, when a metal hydroxide surface-treated with a silane coupling agent, particularly an aminosilane coupling agent, is used, the coupling agent has a functional group reactive with an inorganic substance and a functional group reactive with an organic substance in the molecule. Since it has a metal hydroxide and an acid anhydride, it binds firmly.
Therefore, the mechanical strength, particularly the wear resistance, can be significantly improved without impairing the flexibility of the resin composition. Further, when an amino group or an epoxy group is present on the lipophilic group side of the silane coupling agent, the polyolefin and the olefin-based polymer modified with an acid anhydride react with such a group to form such a group. Hydrophilicity can be suppressed.

[0019]

The present invention will now be described more specifically with reference to examples and comparative examples. Examples 1 to 3 and Comparative Examples 1 to 4 The components shown in Tables 1 and 2 were mixed in the indicated amounts and kneaded at 250 ° C by a twin-screw extruder. The resulting composition was extruded around a 0.5 sq stranded conductor (7 / 0.32 annealed copper wire) with a coating thickness of 0.3 mm. Dies and nipples having diameters of 1.6 mm and 1.0 mm, respectively, were used for the extrusion molding. The extrusion temperature was set at a die of 210 to 230 ° C. and a cylinder of 200 to 240 ° C., and extrusion was performed at a linear speed of 100 m / min.

The meanings of the abbreviations in the table are as follows. Propylene BP: Propylene-ethylene block copolymer (MFR0.5) (RB610 manufactured by Tokuyama Corporation)
A). GMA-EVA: glycidyl methacrylate-ethylene-vinyl acetate copolymer (Bond Fast 7B manufactured by Sumitomo Chemical Co., Ltd .; glycidyl methacrylate content 12% by weight, VA content 5% by weight). SEBS: a styrene-based elastomer in which the double bond of a block copolymer with polybutadiene is saturated by hydrogenation (ToughTech H1041 manufactured by Asahi Kasei Corporation). Kisuma 5NH: magnesium hydroxide (Kyowa Chemical Co., Ltd.) surface-treated with an aminosilane coupling agent. As the anti-aging agent, a hindered phenol-based anti-aging agent (trade name "Tominox TT" (manufactured by Yoshitomi Pharmaceutical Co., Ltd.)) was used.

The insulated wires obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were measured for flame retardancy, tensile strength / elongation, and wear resistance according to JASO (Japan Automobile Engineering Association) D 611. did. The abrasion resistance is an average of 3 samples, and 5
Pass 00 or more times. Flexibility when bending the wire
It was evaluated by hand feeling. The workability was evaluated based on the presence or absence of mustache when peeling the end of the electric wire. The results are shown in Tables 1 and 2.

[0022]

[Table 1]

[0023]

[Table 2]

As can be seen from the results of Comparative Example 1, if no styrene elastomer is added, the flexibility of the resin composition decreases. On the other hand, as can be seen from the results of Comparative Example 3, when the added amount of the styrene-based elastomer is too large, the wear resistance of the resin composition decreases. As can be seen from the results of Comparative Example 2, the abrasion resistance of the resin composition is not improved unless an olefin copolymer resin of an epoxy group-containing comonomer and an olefin is added. On the other hand, as can be seen from the results of Comparative Example 4, even when the addition amount of the olefin copolymer resin of the epoxy group-containing comonomer and the olefin is too large,
The wear resistance of the resin composition decreases.

Examples 4 to 6 and Comparative Examples 5 to 8 Coated wires were produced in the same manner as in Examples 1 to 3, except that the components shown in Tables 3 and 4 were used, and their characteristics were evaluated. The results are shown in Tables 3 and 4. In the table, MAH-SEBS
Means a styrene-based elastomer modified by maleic anhydride and having a double bond of a block copolymer with polybutadiene saturated by hydrogenation (Tuftec M1913 manufactured by Asahi Kasei Corporation), and other abbreviations are shown in Tables 1-2. Is the same as

[0026]

[Table 3]

[0027]

[Table 4]

As can be seen from the results of Comparative Example 5, the flexibility of the resin composition is reduced unless the acid anhydride-modified styrene elastomer is added. On the other hand, as can be seen from the results of Comparative Example 7, when the added amount of the styrene-based elastomer is too large, the wear resistance of the resin composition decreases. As can be seen from the results of Comparative Example 6, unless the olefin copolymer resin of the epoxy group-containing comonomer and the olefin is added, the abrasion resistance of the resin composition is not improved. On the other hand, as can be seen from the results of Comparative Example 8, even if the addition amount of the olefin copolymer resin of the epoxy group-containing comonomer and the olefin is too large, the wear resistance of the resin composition decreases.

Examples 7 to 9 and Comparative Examples 9 to 13 Coated electric wires were produced in the same manner as in Examples 1 to 3 except that the components shown in Tables 5 to 6 were used, and their characteristics were evaluated. The results are shown in Tables 5-6. In the table, MAH-PP is 1
MAH-EVA: Ethylene-vinyl acetate copolymer (manufactured by Mitsui DuPont Chemical Co., Ltd.) modified with maleic anhydride of 1% by weight. HPR VR103), and other abbreviations are the same as in Tables 1 and 2.

[0030]

[Table 5]

[0031]

[Table 6]

As can be seen from the results of Comparative Examples 9 and 12, when the amount of the acid anhydride-modified polyolefin is too large, the flexibility of the resin composition decreases. Also, as can be seen from the results of Comparative Examples 10 and 11, the acid anhydride-modified polyolefin was not contained or the content was too small, and the amount of the olefin copolymer resin of the epoxy group-containing comonomer and the olefin was too large. Then, the abrasion resistance of the resin composition decreases.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/44 H01B 3/44 GMP 7/29 7/34 A (72) Inventor Koji Fujimoto Mie 1-14 Nishisuehirocho, Yokkaichi City Sumitomo Wiring Systems Co., Ltd. F-term (reference) 4J002 AC08Y BB03W BB05W BB06W BB07W BB08W BB10X BB12W BB14X BB15W BB15Y BB17W BB17X FD21 FB17 FB FB FB FB FB EB FB FB FB FB FB FB FB FB FB FB FB FB EB FB FB FB FB FB EB FB FB FB FB EB FB FB FB FB EB FB FB FB FB FB FB FB FB FB 140 GQ01 5G305 AA02 AB15 AB25 BA13 CA01 CA15 CA47 CA51 CC03 CD06 5G315 CA04 CD02 CD03 CD14

Claims (5)

[Claims] 1. (a) 20 to 70 parts by weight of a polyolefin resin, (b) 5 to 60 parts by weight of an olefin copolymer resin of an olefin with an epoxy group-containing comonomer of 0.1 to 20% by weight, and (c) (C1) a styrene-based elastomer, (c2) 0.
At least one polymer component selected from the group consisting of a styrenic elastomer modified with 1 to 20% by weight of an acid anhydride and (c3) a polyolefin modified with 0.1 to 20% by weight of an acid anhydride 5 to 60 parts by weight (provided that the total of components (a), (b) and (c) is
100 parts by weight. And (c) an olefin resin composition comprising 30 to 200 parts by weight of a metal hydroxide. 2. The olefin resin composition according to claim 1, wherein the proportion of the polymer component (c) is 40 to 10 parts by weight, and the proportion of the metal oxide is 50 to 150 parts by weight. 3. The olefin resin composition according to claim 1, wherein the metal hydroxide is magnesium hydroxide surface-treated with a coupling agent. 4. The olefin resin composition according to claim 3, wherein the metal hydroxide is magnesium hydroxide surface-treated with a silane coupling agent. 5. An electric wire coated with the olefin-based resin composition according to claim 1.