JP2000195336A - Electric wire coating resin composition and insulated electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nonhalogen electric wire coating resin composition and an insulated electric wire superior in flame resistance, mechanical characteristics, and electrical insulation, with no elution of a heavy metal compound or a phosphide, and without generating a large amount of smoke and a corrosive gas. SOLUTION: This composition for an insulation coated electric wire contains 100-250 pts.wt. metal hydrate, surface-treated with both a fatty acid, such as stearic acid, oleic acid, and/or the like, and a silane-coupling agent having an epoxy group and/or a vinyl group as a terminal group, to 100 pts.wt. polyolefin-based resin, while the conductor of this insulated electric wire is coated with a crosslinked material of this composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for covering an insulated wire used for internal and external wiring of electric and electronic equipment, and an insulated wire covered with the composition. At the time of disposal such as combustion,
The present invention relates to a resin composition for covering electric wires, which does not elute heavy metal compounds and does not generate a large amount of smoke or corrosive gas, and an insulated wire coated with the same.

[0002]

2. Description of the Related Art Polyvinyl chloride (PVC) compounds and halogen-based flame retardants containing bromine atoms and chlorine atoms in the molecule are used as covering materials for insulated wires used for internal and external wiring of electric / electronic devices. It is well known to use a resin composition containing a blended ethylene copolymer as a main component. However, if these materials are disposed of without proper treatment, the plasticizers and heavy metal stabilizers contained in the coating materials will elute, and if they are burned, corrosive gases will be generated from the halogen compounds contained in the coating materials. And dioxins may be generated, and in recent years, this problem has been discussed. For this reason, a technique for coating an electric wire with a non-halogen flame-retardant material that is not likely to elute harmful heavy metals or generate a halogen-based gas has begun to be studied. Non-halogen flame-retardant materials exhibit flame retardancy by blending a flame retardant containing no halogen into the resin. Examples of the flame retardant include metal hydrates such as magnesium hydroxide and aluminum hydroxide. Examples of the resin include polyethylene, ethylene / 1-butene copolymer, ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, and ethylene / propylene / diene terpolymer. Copolymers and the like are used.

On the other hand, electronic wire harnesses and other insulated wires for electric / electronic devices used in electronic devices have very strict flame-retardant standards from the viewpoint of safety, for example, UL15.
81 (Reference Standard for Wires, Cables and Flexible Cords)
for Electrical Wires, Cabl
es, and Flexible Cords) and the like.
(Flame Test), the VW-1 standard, the horizontal flame retardant standard, and the 60-degree inclined flame retardant characteristics specified in JIS C3005. Further, such a resin composition for covering electric wires is required to have high mechanical properties such as a breaking elongation of 100% and a breaking tensile strength of 10 MPa or more in accordance with UL, electric appliance control standards, and the like.

[0004] A flame retardant resin composition comprising a thermoplastic resin such as polyolefin as a base resin and a large amount of a metal hydrate as a non-halogen flame retardant is blended with the resin to provide good flame retardancy. However, there is a problem that the mechanical properties are significantly reduced. In order to solve this problem, the surface of magnesium hydroxide is subjected to various surface treatments to improve the elongation at break and the tensile strength at break of the resin composition for covering electric wires. For example, it is known that the elongation at break of a resin composition for covering electric wires is improved by using magnesium hydroxide treated with stearic acid as a surface treatment material. It has also been proposed to add a silane coupling agent to untreated magnesium hydroxide at the time of kneading to perform a surface treatment to maintain the breaking tensile strength (Japanese Patent No. 2525982). As a necessary property of an insulated wire, it is required to maintain electrical insulation properties that can withstand long-term use, and for that purpose, it is required to maintain a high volume resistivity of the resin composition for wire coating after a heat aging test. However, as described above, non-halogen resin compositions containing a large amount of magnesium hydroxide did not provide satisfactory mechanical properties or had a significant decrease in volume resistivity after a heat aging test. It has been found that it is difficult with conventional techniques to achieve both mechanical properties and volume resistivity after a heat aging test.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention has a high level of flame retardancy and excellent mechanical properties, and can be used for disposal of heavy metal compounds and phosphorus compounds at the time of disposal, such as landfilling and combustion. It is an object of the present invention to provide an electric wire coating resin composition and an insulated electric wire which can maintain high electrical insulation properties for a long period of time without elution of water or generation of a large amount of corrosive gas.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the type of the metal hydrate surface treatment agent to be added to the base resin is determined by the volume after the heat aging test. The inventors have found that the specific resistance value is affected, and have completed the present invention based on the findings.

That is, the present invention relates to (1) 100 to 25 parts by weight of a polyolefin resin, 100 to 25 metal hydrates surface-treated with a fatty acid and a silane coupling agent.
(2) The resin composition for covering electric wires according to (1), wherein the fatty acid is stearic acid and / or oleic acid. (3) The resin composition for covering an electric wire according to (1) or (2), wherein the terminal group of the silane coupling agent is an epoxy group and / or a vinyl group, and (4) (1) ), (2) or (3), wherein the conductor is covered with a crosslinked body of the resin composition described in (2) or (3).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the resin composition of the present invention will be described. The resin composition of the present invention comprises a polyolefin-based resin and a metal hydrate surface-treated with a fatty acid and a silane coupling agent. Examples of the polyolefin resin in the resin composition of the present invention include ethylene-based copolymers such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and ethylene-acrylic acid copolymer. Coalescence can be mentioned. In addition, ultra low density polyethylene (VLDP)
E), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (M
DPE), high-density polyethylene (HDPE), ultra-low-density polyethylene (VLDPE), and linear polyethylene polymerized using a single-site catalyst. Further, polypropylene resins such as an ethylene-propylene random copolymer (R-PP) and an ethylene-propylene block copolymer (B-PP) can be exemplified.

In view of flame retardancy, ethylene-vinyl acetate copolymer is particularly preferred. These polyolefin resins may be used alone or in combination of two or more. Further, polyethylene and / or polypropylene modified with an unsaturated carboxylic acid may be used in combination. Here, the main component in the present invention is
The ratio of polyolefin resin in the whole resin component is 8
0% by weight or more.

[0010] The polyethylene and / or polypropylene modified with an unsaturated carboxylic acid is a resin obtained by modifying polyethylene and / or polypropylene with an unsaturated carboxylic acid or a derivative thereof. As, for example, maleic acid, itaconic acid, fumaric acid and the like, as the unsaturated carboxylic acid derivative, maleic acid monoester, maleic acid diester, maleic anhydride, itaconic acid monoester, itaconic acid diester, anhydride Examples include itaconic acid, fumaric acid monoester, fumaric acid diester, fumaric anhydride and the like. The modification of the polyolefin can be performed, for example, by melting and kneading the polyolefin and an unsaturated carboxylic acid in the presence of an organic peroxide.

Examples of the metal hydrate in the resin composition of the present invention include aluminum hydroxide and magnesium hydroxide. The fatty acid used for the surface treatment of the metal hydrate is not particularly limited. Oleic acid and the like can be mentioned. The blending amount of this fatty acid is 100
Fatty acids of 0.2 to 5% by weight, preferably 0.2 to 2% by weight, based on% by weight are suitably used. The silane coupling agent in the present invention has a vinyl group, a glycidyl group, or an amino group at the terminal, and among them, a compound having a vinyl group or a glycidyl group is preferable. As a silane coupling agent, vinyltrimethoxysilane,
Vinyltriethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, glycidoxypropylmethyldimethoxysilane,
Methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropylmethyldimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane, N- (β- Aminoethyl)-
γ-aminopropyltripropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltripropyltrimethoxysilane and the like. Among these silane coupling agents, it is preferable to use a silane coupling agent having an epoxy group and / or a vinyl group as a terminal group in view of breaking tensile strength and flame retardancy.

[0012] The metal hydrate may be treated with both stearic acid and a silane coupling agent at the time of production, or both may be treated by adding stearic acid and a silane coupling agent to untreated magnesium hydroxide and blending them. It may be processed. Alternatively, a surface treatment may be performed by adding a silane coupling agent to a metal hydrate surface-treated with a fatty acid in advance. Substantially, the case where a silane coupling agent is added to a metal hydrate whose surface is treated with a fatty acid and the surface of the metal hydrate is subjected to a surface treatment is more effective from the viewpoint of cost and production. Magnesium hydroxide surface treated with stearic acid is already on the market. Kisuma 5A (Kyowa Chemical Co., Ltd.), Magsheath N-3 (Kamishima Chemical Co., Ltd.) and other products (Kyowa Chemical Co., Ltd.) can be used. Magnesium hydroxide surface-treated with oleic acid is already on the market, and those commercially available under Kisuma 5B or other trade names (Kyowa Chemical Co., Ltd.) can be used. The processing ratio of fatty acids can be changed by manufacturers such as Kyowa Chemical Co., Ltd. and Kamishima Chemical Co., Ltd.

When the surface of the metal hydrate is treated with a fatty acid by adding a silane coupling agent to the metal hydrate, the surface of the metal hydrate is partially treated with a fatty acid in advance. Add a silane coupling agent to the hydrate,
Stirring with a blender, and adding heat-treated after stirring at the time of kneading, or adding a crosslinkable silane coupling agent to the metal hydrate whose surface has been treated with a fatty acid during kneading. Performs the surface treatment.
The amount of the silane coupling agent to be added is preferably about 0.2 to 2% by weight, more preferably about 0.4 to 1.2% by weight, based on 100% by weight of the metal hydrate.

The composition of the present invention preferably further contains zinc stannate, zinc hydroxystannate and zinc borate in order to enhance the flame retardant effect. As zinc borate, those having an average particle diameter of 5 microns or less, particularly preferably about 3 microns are preferable. Commercially available products can be used as zinc borate. For example, Alkanex FRC-500
_{(2ZnO / 3B 2 O 3 ·} 3.5H 2 O), FRC-60
0 (trade name, distributor Mizusawa Chemical), and the like. As zinc stannate, zinc stannate (ZnSn
O ₃ ), zinc hydroxystannate with hydrate (ZnS
n (OH) ₆ ) is preferred, and the trade name is Alkanex Z.
Commercial products such as S, Alcanex ZHS (sold by Mizusawa Chemical) can be used. Zinc hydroxystannate,
Zinc stannate preferably has an average particle size of 5 microns or less, particularly preferably about 3 microns.

Melamine cyanurate may be added as a method for enhancing the flame retardant effect. Melamine cyanurate compounds that can be used in the present invention include, for example, M
There are CA-0 and MCA-1 (both trade names, manufactured by Mitsubishi Chemical Corporation) and those marketed by Chemie Linz GmbH. Examples of the melamine cyanurate compound surface-treated with a fatty acid and the melamine cyanurate compound surface-treated with silane include MC610 and MC640 (both are trade names, manufactured by Nissan Chemical Industries, Ltd.).

In the resin composition for covering electric wires of the present invention, various additives generally used for covering materials of electric wires and cables, for example, antioxidants, metal deactivators, flame retardants ( Auxiliary agents, fillers, lubricants and the like can be appropriately compounded within a range that does not impair the purpose of the present invention.

Examples of the antioxidant include amines such as 4,4'-dioctyl diphenylamine, N, N'-diphenyl-p-phenylenediamine, and a polymer of 2,2,4-trimethyl-1,2-dihydroquinoline. -Based antioxidant, pentaerythrityl-tetrakis (3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-
A phenolic antioxidant such as 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, bis (2-methyl-4- (3-n-alkylthiopropionyloxy)- 5-t-butylphenyl) sulfide, 2-mercaptobenzimidazole and its zinc salt, and sulfur-based antioxidants such as pentaerythritol-tetrakis (3-lauryl-thiopropionate).

Examples of the metal deactivator include N, N'-bis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl) hydrazine, 3- (N-salicyloyl) amino-1, 2,4-triazole, 2,2′-oxamidobis- (ethyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) and the like. Further, as a flame retardant (auxiliary) agent and filler, carbon, clay, zinc oxide, tin oxide, titanium oxide, magnesium oxide, molybdenum oxide, antimony trioxide, silicone compound, quartz, talc, calcium carbonate, magnesium carbonate, boric acid Zinc, white carbon and the like. Examples of the lubricant include hydrocarbon-based, fatty acid-based, fatty acid amide-based, ester-based, alcohol-based, and metallic soap-based lubricants.
An ester-based lubricant exhibiting both internal lubrication and external lubrication simultaneously, such as "P" (trade name, manufactured by Hoechst) is preferable.

Next, the insulated wire of the present invention will be described. The insulated wire of the present invention has a coating layer made of the resin composition of the present invention on a conductor (for example, a single wire or stranded conductor made of soft copper or the like), and the coating layer is a crosslinked body of the resin composition. It is composed. In the insulated wire of the present invention, by forming the coating layer by crosslinking the resin composition, not only the heat resistance can be improved, but also the flame retardancy can be improved. As a crosslinking method, an electron beam crosslinking method or a chemical crosslinking method by a conventional method can be adopted. In the case of the electron beam crosslinking method, crosslinking is performed by irradiating an electron beam after extruding a resin composition constituting the coated wire to form a coating layer. The dose of the electron beam is appropriately 1 to 30 Mrad, and in order to efficiently perform crosslinking, the resin composition constituting the coating layer is formed by adding a methacrylate-based compound such as trimethylolpropane triacrylate or an allyl-based compound such as triallyl cyanurate. A polyfunctional compound such as a compound, a maleimide compound or a divinyl compound may be blended as a crosslinking aid. In the case of the chemical crosslinking method, for example, dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-
(T-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,
An organic peroxide such as 1,3-bis (tert-butylperoxyisopropyl) benzene or t-butylcumyl peroxide is compounded as a cross-linking agent, extruded to form a coating layer, and then subjected to heat treatment by a conventional method. Perform cross-linking. In the insulated wire of the present invention, the thickness of the insulating coating layer formed around the conductor is not particularly limited, but is usually 0.15 mm to 1 mm.
mm.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In addition, numerals show a weight part unless there is particular description. (Examples 1 to 10 and Comparative Examples 1 to 6) First, the components shown in Tables 1 to 3 were dry-blended at room temperature and melt-kneaded using a Banbury mixer to obtain a resin composition for each insulating coating layer. Prepared. Next, a conductor (conductor diameter: 0.95 mmφ tinned soft copper stranded wire)
(Structure: 21 pieces / 0.18 mmφ) is coated with a resin composition for insulating coating previously melt-kneaded by extrusion.
Insulated wires corresponding to each example and comparative example were manufactured. The outer diameter was set to 2.63 mm. After coating, crosslinking was performed by irradiating with an electron beam at 10 Mrad.

For each of the obtained insulated wires, tensile properties,
The flame retardancy was evaluated, and the results are shown in Tables 1 to 3.
Test methods and evaluation conditions are shown below. -Tensile properties (tensile strength, elongation at break) The covering layer of each insulated wire is made into a tubular piece, and its tensile strength (tensile strength) (MPa) and elongation (%) are measured using a tensile tester to a tensile strength of 25 mm between the marked lines. Speed 500 mm / min. It measured on condition of. The required properties of tensile strength and elongation are 1
0 MPa or more and 100% or more. -Flame retardancy For each insulated wire, a horizontal flame test (Vertical Flame Test) specified in UL1581 was performed on 5 samples, and the ratio of those that passed was shown. -Volume resistivity The insulation resistance specified in JIS C3005 was measured for the initial and each insulated wire heated at 158 ° C for 168 hours, and the volume resistivity was calculated by the following conversion formula. The required characteristics of the volume resistivity are 1 × 10 13 Ωcm or more at the initial stage and after aging by heating at 158 ° C. for 7 days. ρ = (L / 3.665) · (1 / (log ₁₀ (D /
d))). 10 ⁷

The components shown in Tables 1 to 3 were as follows. (01) Ethylene-vinyl acetate copolymer (EVA) Vinyl acetate (VA) component content 33% by weight (02) Ethylene-ethyl acrylate copolymer (EEA) Ethyl acrylate (EA) component content 25% by weight (03) ) Polyethylene EG8003 (trade name, manufactured by Dow Chemical Co., Ltd.) Density 0.86 (04) Maleic anhydride-modified LLDPE Adtech L6100M (trade name, manufactured by Nippon Polyolefin Co., Ltd.) (05) Untreated magnesium hydroxide Kisuma 5 (trade name, Kyowa) (06) Magnesium hydroxide stearic acid surface treated Kisuma 5A (trade name, manufactured by Kyowa Chemical Co., Ltd.) (07) Stearic acid surface treated magnesium hydroxide NO. 1 0.5% by weight stearic acid-treated product (08) Stearic acid surface-treated magnesium hydroxide low-treated product NO. 2 1.8% by weight stearic acid-treated product (09) Stearic acid surface-treated magnesium hydroxide low-treated product NO. 3 0.3% by weight stearic acid treated product (10) Stearic acid surface-treated magnesium hydroxide low-treated product NO. 4 2.5% by weight stearic acid-treated product (11) Oleic acid surface-treated magnesium hydroxide low-treated product NO. 5 Treated with 0.5% by weight of oleic acid (12) Silane coupling agent having a vinyl group at the end TSL8311 (trade name, manufactured by Toshiba Silicone Co.) Vinyl ethoxysilane (13) Silane coupling agent having an epoxy group at the end TSL8350 (Trade name, manufactured by Toshiba Silicone Co., Ltd.) (14) Hindered phenolic anti-aging agent Irganox 1010 (trade name, manufactured by Ciba Geigy) (15) Zinc salt of 2-mercaptobenzimidazole Nocrack MBZ (trade name, Ouchi Shinko) (16) TMPTM (trimethylolpropane trimethacrylate) Ogmont T-200 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) (17) Magnesium hydroxide Kisuma surface-treated with a silane coupling agent having a vinyl group at the terminal 5LH (trade name, manufactured by Kyowa Chemical Co., Ltd.)

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

As is clear from the results in Tables 1 to 3, insulated wires (Examples 1 to 10) using the resin composition of the present invention
It can be seen that mechanical properties such as elongation and tensile strength, flame retardancy, and electrical properties such as volume resistivity after thermal aging are all excellent. On the other hand, when magnesium hydroxide not surface-treated with a fatty acid was used and a silane coupling agent was not used, both tensile strength and volume resistivity after heat aging were low (Comparative Example 3), and a silane coupling agent was used. Sometimes, the tensile strength shows a high value, but the volume resistivity after heat aging decreases (Comparative Example 2). Moreover, when the magnesium hydroxide treated with the fatty acid is used and the silane coupling agent is not used, the tensile strength decreases (Comparative Example 1). The amount of the metal hydrate is 10 parts by weight based on 100 parts by weight of the resin component containing the ethylene copolymer as a main component.
If the amount is less than 0 parts by weight, the test does not pass the horizontal flame retardant test (Comparative Example 4), and if it exceeds 250 parts by weight, the elongation and tensile strength are low (Comparative Example 5). Further, even when magnesium hydroxide treated with a fatty acid and magnesium hydroxide treated with a silane coupling are blended, the tensile strength decreases (Comparative Example 6).

[0027]

The resin composition for covering electric wires of the present invention has a high level of flame retardancy even when the metal hydrate is highly filled by using a fatty acid and a silane coupling agent in combination as a surface treatment of the metal hydrate. It has properties and mechanical properties and can maintain electrical insulation for a long period of time, and is suitable as a composition for a coating layer of an insulated wire. Further, the insulated wire of the present invention,
Its coating layer is made of non-halogen flame-retardant material, and does not elute heavy metal compounds, generate large amounts of smoke or corrosive gas during disposal and disposal such as landfilling and burning, and is a wiring material for electrical and electronic equipment. Useful as

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Koji Iwata, Inventor F-term (reference) 4F002 BB031 BB061 BB071 BB081 BB151 BB211 BP021 DE076 DE146 FB096 FB106 FB136 FB236 FD070 FD130 GQ01 5G303 AA06 AB12 AB14 AB20 BA04 CA11 CB01 CB17 CD01 5G305 AA02 AB15 AB25 AB35 BA12 BA13 CA01 CA04 CA07 CA51 CA54 CC03 CD13

Claims (4)

[Claims] 1. A resin composition for covering electric wires, wherein 100 to 250 parts by weight of a metal hydrate surface-treated with a fatty acid and a silane coupling agent is blended with 100 parts by weight of a polyolefin resin. object. 2. The resin composition according to claim 1, wherein the fatty acid is stearic acid and / or oleic acid. 3. The resin composition according to claim 1, wherein the terminal group of the silane coupling agent is an epoxy group and / or a vinyl group. 4. An insulated wire having a conductor coated with a crosslinked body of the resin composition for wire coating according to claim 1, 2 or 3.