JP2002124133A - Insulated electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a covered wire with thin wall thickness which does not generate poisonous halogen gas when burned, keeping various properties required for an electric wire of a vehicle, and able to maintain the shape even in the atmosphere of high temperature. SOLUTION: For the insulated electric wire covered with an inner layer made of polyolefin resin component, and an outer layer made of polyamide resin, the polyolefin resin component contains a polyolefin thermoplastic elastomer with a melting point of 130 deg.C or more and a Shore hardness of 90 or less by 5-80 mass part, a polyolefin denatured by 0.1-10 weight % of unsaturated carbonic acid or the derivative of the same by 1-30 mass part, a styrene group elastomer denatured by styrene group elastomer, or 0.1-10 weight % of unsaturated carbonic acid or the derivative of the same by 5-50 mass part, a propylene polymer by 0-80 mass part, and 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 improved coated electric wire coated with an inner layer of a polyolefin resin composition and an outer layer of a polyamide resin.

[0002]

2. Description of the Related Art Mechanical strength,
Polyvinyl chloride (PVC) has been mainly used from the viewpoints of wire extrusion processability, flexibility, coloring properties, economy, and the like. However, since PVC is a chlorine-containing polymer,
It is regarded as a problem because it emits harmful chlorine gas during combustion and pollutes the global environment. From such a background, a halogen-free material has been used instead of PVC as an electric wire coating material. Conventional halogen-free materials emphasize heat resistance and abrasion resistance, and add metal hydroxide as a flame retardant to an olefin-based elastomer, for example, a propylene-ethylene-propylene copolymer, and further use a fatty acid salt or the like as a lubricant. The added composition is used.

[0003] In particular, increasingly high flame retardancy is required for automotive wire covering materials, and a flame-retardant resin composition obtained by blending a metal hydroxide with an olefin resin is used as the wire covering. (For example, Japanese Patent Application Laid-Open Nos. 5-194799 and 10-340636).
JP-A-10-340637 and the like. However, in order to satisfy the required flame retardancy, it is necessary to mix a large amount of metal hydroxide. However, in such a resin composition, mechanical strength such as abrasion resistance and tensile strength may be extremely reduced. Therefore, it is conceivable to increase the blending amount of polypropylene or high-density polyethylene having relatively high hardness, but the flexibility of the coated electric wire is impaired, and the processability of the resin composition is also deteriorated.

On the other hand, the electric wire coating has a multi-layer structure, the outer layer is made of an olefin resin containing little or no flame retardant, and the inner layer is made of a flame retarded olefin resin containing a large amount of flame retardant. Also, there has been proposed a coated electric wire having both abrasion resistance and flexibility (JP-A-6-17663).
No. 1). However, such a multi-layer coated electric wire is not sufficiently deformable at high temperatures.

[0005]

DISCLOSURE OF THE INVENTION The present invention does not generate harmful halogen gas during combustion, and provides flame retardancy, abrasion resistance, flexibility, tensile properties, heat deformability and electric wire required for electric wires for automobiles. An object of the present invention is to provide a coated electric wire capable of maintaining its shape even at a high temperature, for example, a high-temperature atmosphere of 180 ° C. while maintaining various properties such as extrudability and workability.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an insulated wire covered with an inner layer made of a polyolefin resin composition and an outer layer made of a polyamide resin. Is
(A) Polyolefin thermoplastic elastomers 5 to 8 having a melting point of 130 ° C. or more and a Shore A hardness of 90 or less.
0 parts by mass, (b) polyolefin 1 modified with 0.1 to 10% by mass of unsaturated carboxylic acid or derivative thereof
To 30 parts by mass, (c) 5 to 50 parts by mass of a styrene-based elastomer or a styrene-based elastomer modified with 0.1 to 10% by mass of an unsaturated carboxylic acid or a derivative thereof, and (d) 0 to 80 parts by mass of a propylene polymer Parts (provided that the total of (a) to (d) is 100 parts by weight) and (e) 30 to 250 parts by weight of metal water based on 100 parts by weight of the components (a) to (d). Provided is a coated electric wire comprising an oxide.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, each component contained in the resin composition of the inner layer and the outer layer of the coated electric wire of the present invention will be described. <Inner layer> Polyolefin thermoplastic elastomer (a)
Can be selected from known polyolefin thermoplastic elastomers as long as they have a melting point of 130 ° C. or more and a Shore A hardness of 90 or less. Preferred examples of the polyolefin thermoplastic elastomer include an ethylene-propylene copolymer rubber.

[0008] The blending amount of the polyolefin thermoplastic elastomer is 5 parts per 100 parts by mass of the total of components (a) to (d).
８０80 parts by weight, preferably 10-60 parts by weight. When the blending amount of the polyolefin thermoplastic elastomer is less than 5 parts by mass, the flexibility and processability of the composition decrease. On the other hand, when the compounding amount exceeds 80 parts by weight, the abrasion resistance of the composition decreases. When an elastomer having a melting point of less than 130 ° C. is used, heat resistance (heat deformability) deteriorates, and a problem occurs in practical use. When the Shore A hardness exceeds 90,
Flexibility is impaired.

Polyolefins modified with unsaturated carboxylic acids or derivatives thereof include polypropylene,
Polybutene, high-density polyethylene, linear low-density polyethylene, low-density polyethylene, ethylene copolymer (for example, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, etc.), ethylene-propylene copolymer, Preferred examples include an ethylene-butene copolymer. The amount of the unsaturated carboxylic acid or derivative thereof used for modifying the polyolefin is 0.1 to 10% by mass based on the mass of the polyolefin. Any unsaturated carboxylic acid or derivative thereof can be used as long as it is conventionally used for modifying a polyolefin resin. Examples of preferred unsaturated carboxylic acids are maleic acid, fumaric acid and the like, and examples of preferred derivatives are maleic anhydride, maleic acid monoester, maleic diester and the like. Among them, maleic anhydride is particularly preferred. The compounding amount of the polyolefin (b) modified with the unsaturated carboxylic acid or its derivative is 10% in total of the components (a) to (d).
It is 1 to 30 parts by mass in 0 parts by mass. If the amount of the modified polyolefin (b) is less than 1 part by mass, the abrasion resistance of the composition is reduced. On the other hand, if the amount exceeds 30 parts by weight, flexibility is impaired.

The styrene elastomer (c) includes:
Conventionally used styrene-based elastomers can be used, for example, styrene-butadiene block copolymer,
A polymer in which a double bond is saturated by hydrogenation, such as a styrene-ethylene-propylene block copolymer, can be preferably used. As the unsaturated carboxylic acid or derivative thereof used for the modification, those used for the modification of the above-mentioned polyolefin can be used. The blending amount of the styrene-based elastomer or the modified styrene-based elastomer (c) depends on the amount of the component (a)
It is 5 to 50 parts by mass in the total of 100 parts by mass of (d). If the amount of the styrene-based elastomer or modified styrene-based elastomer (c) is less than 5 parts by mass, the flexibility and processability of the composition will be reduced. On the other hand, when the compounding amount exceeds 50 parts by mass, the abrasion resistance decreases.

As the propylene polymer (d), propylene homopolymer and propylene as main components (50
Propylene copolymer (e.g., propylene-ethylene block or random copolymer). The blending amount of the propylene polymer (d) is 0 to 80 parts by mass in the total of 100 parts by mass of the components (a) to (d). That is, the propylene polymer (d) is an optional component.

[0012] The metal hydroxide (e) is blended for imparting flame retardancy to the resin composition. Examples of metal oxides include magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like. These metal oxide particles are preferably surface-treated with a silane coupling agent (for example, aminosilane, vinylsilane, epoxysilane, etc.), a titanate coupling agent, a higher fatty acid, or the like. The above-mentioned surface treatment agent can be added by performing an integral blend (added as a compounding agent at the time of mixing). The mixing amount of the metal hydroxide is 30 to 25 with respect to the total of 100 parts by mass of the components (a) to (d).
0 parts by mass, preferably 50 to 150 parts by mass.

The resin composition for the inner layer according to the present invention may contain any additive which is conventionally added to an olefin resin for covering electric wires. Examples of such additives include antioxidants, metal deactivators (eg, copper harm inhibitors), processing aids (eg, lubricants, waxes, etc.), colorants, flame retardant aids (eg, ho Zinc oxide, silicon-based flame retardants, etc.), antistatic agents and the like. The amount of the additive may be appropriately selected according to the type of the additive.

<Outer Layer> The outer layer of the coated electric wire of the present invention is made of a polyamide resin. Any polyamide resin may be used as long as it is used for conventional electric wire coating.
Examples of preferred polyamide resins are nylon 6, nylon 66, nylon 11, nylon 12, nylon 610,
Nylon 612, polyamide elastomer and the like.
These may be used as a blend of two or more.

In the polyamide resin, an ionomer resin, an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, as an impact-resistant agent (or softening agent),
An acrylic rubber, an NBR rubber, a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, a plasticizer (for example, a polyester plasticizer or the like), or a mixture thereof may be blended. In addition, polyamide resins include nitrogen-based flame retardants (eg, melamine cyanurate), flame retardant aids (eg, zinc borate, silicon-based flame retardants, etc.), clay, calcium carbonate, talc, antioxidants, metals Deactivators, processing aids (eg, lubricants, etc.),
An additive such as a coloring agent may be blended.

[0016] The coated electric wire of the present invention comprises an inner layer and an outer layer,
It can be manufactured by extrusion coating on a wire conductor by tandem or common extrusion known in the art. The thickness ratio of the inner layer and the outer layer can be arbitrarily selected from the range of 9: 1 to 1: 9, but is preferably in the range of 5: 5 to 9: 1.

[0017]

Examples 1 to 5 and Comparative Examples 1 to 5 The resins and additives shown in Table 1 or Table 2 were blended, and an inner layer and an outer layer (total thickness) having the thickness shown in the table were mixed using an extruder. 0.2 mm) was covered with a compressed conductor ISO 0.5 sq (7 / SB soft copper wire) to prepare a covered electric wire.

The following characteristics were evaluated for the obtained coated electric wire. Flame retardancy, tensile strength / elongation, and wear resistance were measured in accordance with JASO D 611, respectively. The abrasion resistance is 150 times or more at a load of 7N. The judgment was made based on the hand feeling when the flexible electric wire was bent. When stripping the coating from the workability wire end, as judged by the presence or absence of formation of whiskers. After leaving the heat-deformable coated wire in an atmosphere of 180 ° C. for 10 minutes, 3
When a load of 00 gf was applied for 1 minute, it was determined whether or not the coating was melted and the conductor was exposed. The case where the coating could not maintain the shape and the conductor was exposed was rejected. The results are shown in Tables 1 and 2. Note that “parts” in the table is “parts by weight”.

[0019]

[Table 1]

[0020]

[Table 2] Note: 1) Propylene-ethylene block polymer (manufactured by Tokuyama Corporation; melting point: 150 ° C; Shore A hardness: 9)
0). 2) Maleic anhydride-modified polypropylene (J-LEX manufactured by Japan Polyolefin Co., Ltd.). 3) Styrene-based elastomer in which the double bond of the styrene-butadiene block copolymer is saturated by hydrogenation (ToughTech, manufactured by Asahi Kasei Corporation). 4) Propylene-ethylene block polymer (manufactured by Tokuyama Corporation). 5) Polyamide resin 1: Nylon 6; 2: Nylon 6 with impact resistant material; 3: Nylon 12 (all UBE nylon manufactured by Ube Industries, Ltd.). 6) Kisuma (manufactured by Kyowa Co., Ltd.). 7) Melamine cyanurate (manufactured by Nissan Chemical Industries, Ltd.). 8) Anti-aging agent 1: hindered phenol-based anti-aging agent (manufactured by Yoshitomi Pharmaceutical Co., Ltd.); 2: amine-based anti-aging agent (manufactured by Seiko Chemical Co., Ltd.).

The following can be seen from the results in Table 2. As in Comparative Example 1, only the coating (inner layer) of the olefin-based resin composition is inferior in heat deformability. When the modified polyolefin is not used as in Comparative Example 2, the abrasion resistance is poor. If no styrene elastomer is used as in Comparative Example 3, the flexibility and processability are poor. When no polyolefin thermoplastic elastomer is contained as in Comparative Example 4, flexibility and processability are poor. When the amount of magnesium hydroxide is small as in Comparative Example 5, the flame retardancy is poor.

Examples 6 to 10 and Comparative Examples 6 to 10 The resins and additives shown in Table 3 or Table 4 were blended, and an inner layer and an outer layer (total thickness) having the thickness shown in the table were mixed using an extruder. 0.2 mm) was covered with a compressed conductor ISO 0.5 sq (7 / SB soft copper wire) to prepare a covered electric wire. About the obtained covered electric wire, each characteristic was evaluated like Example 1-5. The results are shown in Tables 3 and 4.

[0023]

[Table 3]

[0024]

[Table 4] Notes: 1), 2), 4) to 8) See notes in Tables 1 and 2. 3) A styrene-based elastomer in which double bonds of a styrene-butadiene block copolymer have been saturated by hydrogenation and modified with maleic anhydride (ToughTech, manufactured by Asahi Kasei Corporation).

From the results in Table 4, the following can be understood. As in Comparative Example 1, only the coating (inner layer) of the olefin-based resin composition is inferior in heat deformability. When the modified polyolefin is not used as in Comparative Example 2, the abrasion resistance is poor. If no modified styrene elastomer is used as in Comparative Example 3, the flexibility and processability are poor. When no polyolefin thermoplastic elastomer is contained as in Comparative Example 4, flexibility and processability are poor. When the amount of magnesium hydroxide is small as in Comparative Example 5, the flame retardancy is poor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 25/04 C08L 25/04 H01B 7/18 H01B 7/18 B 7/295 7/34 B F term ( Reference) 4J002 BB12Z BB14Z BB15W BB15Z BB21X BP01Y BP02Z DE076 DE086 DE146 GQ01 5G309 RA03 RA04 5G313 AA10 AB03 AC03 AD03 AE05 5G315 CA04 CB02 CC08 CD02 CD14

Claims (2)

[Claims] 1. An insulated wire covered with an inner layer made of a polyolefin resin composition and an outer layer made of a polyamide resin, the polyolefin resin composition comprising: (a) a melting point of 130 ° C. or more and a Shore A of 90 or less. Hard polyolefin thermoplastic elastomer 5-8
0 parts by mass; (b) 1 to 30 parts by mass of a polyolefin modified with 0.1 to 10% by mass of an unsaturated carboxylic acid or a derivative thereof; (c) styrene-based elastomer or 0.1 to 10% by mass of 5 to 50 parts by mass of a styrene elastomer modified with a saturated carboxylic acid or a derivative thereof, (d) 0 to 80 parts by mass of a propylene polymer (however,
The total of (a) to (d) is 100 parts by weight. And (e) a coated electric wire comprising 30 to 250 parts by weight of metal hydroxide based on 100 parts by weight of the total of the components (a) to (d). 2. The ratio of the thickness of the inner layer to the thickness of the outer layer is 1: 9.
The coated electric wire according to claim 1, wherein the ratio is ９9: 1.