JP2002140939A - Insulated wire - Google Patents

Abstract

(57) [Abstract] [Problem] No harmful halogen gas is generated during combustion, and flame retardancy, wear resistance, flexibility, tensile properties, heat deformability, wire extrudability, processing required for automotive wires Provided is a covered electric wire that can maintain its shape even in a high-temperature atmosphere while maintaining various properties such as properties. An insulated wire covered with an inner layer made of a polyolefin resin composition and an outer layer made of a polyamide resin, wherein the polyolefin resin composition comprises:
Propylene polymer, polyolefin thermoplastic elastomer having a melting point of 130 ° C. or more and a Shore A hardness of 90 or less, optionally a polyolefin modified with 0.1 to 10% by mass of an unsaturated carboxylic acid or a derivative thereof, and a metal hydroxide A covered electric wire comprising:

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]

According to a first aspect of the present invention, there is provided 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 comprises: (a) a propylene polymer 30 to 90;
Parts by mass, (b) 10 to 70 parts by mass of a polyolefin thermoplastic elastomer having a melting point of 130 ° C. or more and a Shore A hardness of 90 or less (however, the total of (a) and (b) is 100 parts by mass) and (C) A coated electric wire comprising 30 to 300 parts by mass of a metal hydroxide based on 100 parts by mass of the total of the components (a) and (b), and as a second invention, a polyolefin resin composition. An insulated wire covered with an inner layer and an outer layer made of a polyamide resin, wherein the polyolefin resin composition comprises (a)
20 to 95 parts by mass of propylene polymer, (b) 130 ° C
4 to 80 parts by mass of a polyolefin thermoplastic elastomer having the above melting point and a Shore A hardness of 90 or less,
(E) 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 (the total of (a), (b) and (e) is 10
0 parts by mass. ) And (c) component (a),
30 to 30 parts by mass in total of (b) and (e)
Provide a coated electric wire comprising 250 parts by mass of a metal hydroxide.

[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> Examples of the propylene polymer (a) include a propylene homopolymer and a propylene copolymer containing propylene as a main component (50% by mass or more) (for example, propylene-ethylene block or random copolymer, propylene-ethylene-propylene block polymer, propylene). -Butene copolymer). Among propylene polymers, 0.1 to 5 g / 10
Those having a melt flow rate of min are preferred. In particular, in the first invention, it is desirable to use a propylene polymer having a melt flow rate of 0.1 to 5 g / 10 min.

[0008] The amount of the propylene polymer (a) is 30 parts by weight in the first invention, based on 100 parts by mass of the components (a) and (b) (the first invention) or those and the component (e) (the second invention) in total. To 90 parts by mass, preferably 40 to 90 parts by mass, and 20 to 95 parts by mass, preferably 20 to 90 parts by mass in the second invention.
85 parts by mass. If the amount of the propylene polymer is less than the above lower limit, the abrasion resistance of the composition will be poor. On the other hand, if it exceeds the above upper limit, the flexibility of the composition is poor.

The polyolefin thermoplastic elastomer (b) can be selected from known polyolefin thermoplastic elastomers as long as it has 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 ethylene-
Propylene copolymer rubber and the like can be mentioned.

[0010] The blending amount of the polyolefin thermoplastic elastomer (b) is such that the total amount of the components (a) and (b) (first invention) or those and component (e) (second invention) is 100 parts by mass. 10 to 70 parts by mass, preferably 10
In the second invention, the amount is 4 to 80 parts by mass, preferably 10 to 60 parts by mass. If the amount of the polyolefin thermoplastic elastomer is less than the above lower limit, the flexibility and processability of the composition are reduced. On the other hand, when the compounding amount exceeds the above upper limit, 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, causing problems in practical use. If the Shore A hardness exceeds 90, flexibility is impaired.

The polyolefin in the component (e) of the second invention includes polypropylene, polybutene, polyethylene (for example, high density polyethylene, low density polyethylene, linear low density polyethylene, etc.), ethylene-α-
Examples thereof include olefin copolymers (eg, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer), ethylene-propylene rubber, ethylene-butene copolymer, and the like.

The amount of the unsaturated carboxylic acid or its derivative used for modifying the polyolefin is from 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 acid diester and the like. Among them, maleic anhydride is particularly preferred.

In the second invention, the compounding amount of the polyolefin (e) modified with the unsaturated carboxylic acid or its derivative is 10% in total of the components (a), (b) and (e).
It is 1 to 30 parts by mass in 0 parts by mass. If the amount of the modified polyolefin (e) 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 mass, the flexibility is impaired.

The metal hydroxide (c) is blended for imparting flame retardancy to the resin composition. Examples of metal oxides include magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like. The particles of these metal oxides are preferably coated with (d) a silane coupling agent (eg, vinyl silane, amino silane, vinyl silane, epoxy silane, methacryl silane, mercapto silane, etc.), a titanate coupling agent, a higher fatty acid, etc. Is being processed. The above-mentioned surface treatment agent can be added by performing an integral blend (added as a compounding agent at the time of mixing). In the first invention, it is preferable that the silane coupling agent is not coated on the metal oxide in advance, but is directly added to the composition. The amount of the metal hydroxide to be added is 3 parts per 100 parts by mass of the components (a) and (b) (the first invention) or the total of the components (e) (the second invention).
0 to 250 parts by mass, preferably 50 to 150 parts by mass. In the case where the silane coupling agent is blended as it is in the first invention, the amount thereof is 1 in total of the components (a) and (b)
Desirably, the amount is at least 0.1 part by weight based on 00 parts by weight.

In the resin composition for the inner layer of the present invention, any additive which is conventionally added to olefin resins for covering electric wires can be added. 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 formed 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.

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.

[0019]

Examples 1 to 5 and Comparative Examples 1 to 4 Resins and additives shown in Table 1 or Table 2 were blended, and an inner layer and an outer layer having a thickness shown in the table (total thickness) were extruded 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 mass”.

[0021]

[Table 1]

[0022]

[Table 2] Note: 1) Propylene block polymer (manufactured by Tokuyama Corporation). 2) Ethylene-propylene rubber copolymer (PER manufactured by Tokuyama Corporation; melting point: 150 ° C. Shore A hardness: 9)
0). 3) Polyamide resin 1: Nylon 6; 2: Nylon 6 with impact-resistant material; 3: Nylon 12 (all UBE nylon manufactured by Ube Industries, Ltd.). 4) Kisuma (manufactured by Kyowa Corporation). 5) Melamine cyanurate (manufactured by Nissan Chemical Industries, Ltd.). 6) 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.). 7) Amino coupling agent (manufactured by Shin-Etsu 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. If no polyolefin thermoplastic elastomer is used as in Comparative Example 2, the flexibility is poor. If no propylene polymer is used as in Comparative Example 3, the abrasion resistance is poor. When the amount of magnesium hydroxide is small as in Comparative Example 4, the flame retardancy is poor.

Examples 6 to 10 and Comparative Examples 5 to 9 The resins and additives shown in Table 3 or Table 4 were blended, and the inner layer and the outer layer (total 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.

[0025]

[Table 3]

[0026]

[Table 4] Notes: 1) to 7) See notes in Tables 1 and 2. 8) Maleic anhydride-modified polypropylene (Adtex manufactured by Nippon Polyolefin Co., Ltd.).

The following can be seen from the results in Table 4. As in Comparative Example 5, only the coating (inner layer) of the olefin-based resin composition is inferior in heat deformability. As in Comparative Example 6, when the modified polyolefin is not used, the abrasion resistance is poor. If no polyolefin thermoplastic elastomer is used as in Comparative Example 7, flexibility and processability are poor. Comparative Example 8
When the polyolefin thermoplastic elastomer is excessively contained, the abrasion resistance is poor. As in Comparative Example 9, if the amount of magnesium hydroxide is small, the flame retardancy is poor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 7/18 H01B 7/18 B 7/17 Z 7/29 7/34 A (72) Inventor Shinichi Matsumoto 1-14 Nishi-Suehiro-cho, Yokkaichi-shi, Mie F-term in Sumitomo Wiring Systems Co., Ltd. (Reference) 4J002 BB12W BB14W BB15W BB15X BB213 BP02W DE076 DE086 DE146 EX017 EX067 EX077 EX087 FB096 FB136 FB146 FB156 G0201 AD03 AE07 5G315 CA02 CA03 CA04 CB02 CC09 CD02 CD09 CD14

Claims (5)

[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, wherein the polyolefin resin composition comprises: (a) 30 to 90 parts by mass of a propylene polymer; Polyolefin thermoplastic elastomer having a melting point of 130 ° C. or more and a Shore A hardness of 90 or less
70 parts by mass (however, the total of (a) and (b) is 100 parts by mass) and (c) 30 to 300 parts by mass based on 100 parts by mass of the components (a) and (b). A coated electric wire comprising a metal hydroxide. 2. The coated electric wire according to claim 1, further comprising (d) at least 0.1 part by mass of a silane coupling agent with respect to 100 parts by mass in total of the components (a) and (b). 3. 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 or 2, wherein the ratio is from 9 to 1. 4. An insulated wire covered with an inner layer made of a polyolefin resin composition and an outer layer made of a polyamide resin, wherein the polyolefin resin composition comprises: (a) 20 to 95 parts by mass of a propylene polymer; Polyolefin thermoplastic elastomer having a melting point of 130 ° C. or more and a Shore A hardness of 90 or less 4 to 8
0 parts by mass, (e) 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 (the total of (a), (b) and (e) is 10
0 parts by mass. And (c) a total of 10 of the above components (a), (b) and (e).
A covered electric wire comprising 30 to 250 parts by mass of a metal hydroxide with respect to 0 parts by mass. 5. The ratio of the thickness of the inner layer to the thickness of the outer layer is 1: 9.
The insulated wire according to claim 4, wherein the ratio is up to 9: 1.