JPH11273464A - Insulated electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulated electric wire which is chiefly used in wirings of an electric/electronic apparatus, has a very high heat resistance, excellent low-temp. characteristic and a high degree of fire retardancy, and does not involve elution of heavy metal compound or emission of a large quantity of smoke or corrosive gas when it is disposed of. SOLUTION: An insulated electric wire with fire retardancy has a primary covering layer 3 provided on a conductor 2 and a secondary covering layer 4 provided at the periphery of the primary covering layer 3, wherein the primary layer 3 consists of a resin compound containing a specific polyolefin series resin in an amount 100 pts.wt. as major component, 90-135 pts.wt. metal hydrate, 7-14 pts.wt. red phosphorus, and 1-10 pts.wt. phenol series anti-oxidant, while the secondary layer 4 consists of a fire retardant resin compound containing a specific polyolefin series resin in an amount 100 pts.wt. as major component, 25-80 pts.wt. fire retarding material of polyammonium phosphate type, and 1-10 pts.wt. phenol series anti-oxidant, and therein the condition that primary layer volume/secondary layer volume >=2.8 should be met, and the two covering layers are of bridged structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated wire mainly used for wiring of electric and electronic equipment, and has an extremely high heat resistance, excellent low temperature characteristics, high flame retardancy, and excellent flexibility. The present invention relates to an insulated wire having characteristics such that a coating layer is hardly whitened when the wire is bent.

[0002]

2. Description of the Related Art A coating material for insulated wires used for internal and external wiring of electric and electronic equipment contains a polyvinyl chloride compound or a halogen-based flame retardant containing a bromine atom or a chlorine atom in a molecule. It is well known to use a resin composition containing an ethylene copolymer as a main component. In recent years, appropriate disposal treatment of these electric and electronic devices has been studied. In other words, when electrical equipment and electronic equipment are landfilled and disposed of, plasticizers and heavy metal stabilizers contained in the coating material are eluted, and when incinerated, a large amount of corrosive gas is generated. It is. Therefore, studies on coating non-halogen flame-retardant materials that do not generate harmful heavy metals or halogen-based gases have begun to be actively made.

[0003] Non-halogen flame-retardant materials exhibit flame retardancy by blending a flame retardant containing no halogen into a resin. Examples of the flame retardant include metal hydrates such as magnesium hydroxide and aluminum hydroxide. The product, as the resin, ethylene / 1-butene copolymer, ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, ethylene
For example, a propylene / diene terpolymer is used. When imparting high flame retardancy to such a halogen-free flame retardant material, a large amount of metal hydrate (for example, resin 100
(120 parts by weight or more of metal hydrate with respect to parts by weight), and as a result, there is a problem that the mechanical properties of the flame retardant material deteriorate. To solve this problem, the amount of the metal hydrate is reduced to a small amount (for example, 120 parts by weight or less of the metal hydrate with respect to 100 parts by weight of the resin).
A method of blending red phosphorus has been adopted, and non-halogen flame-retardant materials having both high flame retardancy and mechanical properties have been proposed. Insulated wires for electric and electronic devices that require a high degree of flame retardancy include, for example, UL1581 (Reference).
e Standard for Electrical
Wires, Cables, and Flexible
Cords) vertical flame retardant test VW-1
Vertical flame retardancy that passes the test is required.

[0004]

By the way, the coating material of the insulated wire used for electric and electronic equipment is printed on the surface of the insulated wire for the purpose of distinguishing the kind of the insulated wire and the connection part. And several colors (for example, white,
Black, rat, brown, red, orange, yellow, green, blue, etc.) are used. White or easy to understand print content,
An insulated wire colored in an arbitrary color that is easy to distinguish is manufactured by extrusion-coating a resin composition colored in a target color on a conductor. However, non-halogen flame-retardant materials containing a metal hydrate and red phosphorus in order to achieve both high flame retardancy and mechanical properties cannot be colored white or any color due to the color development of red phosphorus. However, there is a problem that an insulated wire that can easily distinguish the type and the connection portion of the insulated wire cannot be provided.

[0005] As a method for solving this problem, a method in which the coating layer of the insulated wire has a two-layer structure is considered. An example of the insulated wire having the two-layer structure is disclosed in JP-A-62-12006.
And Japanese Patent Application Laid-Open No. 1-258310, however, have problems in extrudability and flame retardancy as described below. That is, the insulated wire disclosed in Japanese Patent Application Laid-Open No. 62-12006 has a two-layered coating, and the inner layer is made of an olefin-based resin composition (specifically, PE, PP, PS,
EPM, EPDM, SBR, IIR, NBR, EEA,
EVA is exemplified), and the outer layer is formed of a high-performance polymer composition (specifically, TPEE, PA, PEEK, PS
E, PC, PESF, etc. are exemplified). However, the high-performance polymer used in the outer layer has drawbacks such as difficulty in extrusion molding, higher cost, and poor flexibility as compared with the olefin-based resin composition. Further, this electric wire has a disadvantage that a whitening phenomenon occurs in which the coating layer portion becomes white when bent, and the inner layer and the outer layer are separated because the resins used for the inner layer and the outer layer are different.

Further, the electric wire / cable disclosed in JP-A-1-258310 has a two-layer coating.
The inner layer is made of a flame retardant composition containing a polyolefin resin and an inorganic hydrate and red phosphorus, and the outer layer is made of a polyolefin resin and an inorganic hydrate that does not contain red phosphorus. It is composed of things. However, in such electric wires and cables, since the resin of the outer layer does not contain red phosphorus, the flame retardancy of the electric wires and cables is limited. In order to improve the flame retardancy, the amount of the inorganic hydrate must be reduced. If the number increases, the mechanical properties deteriorate, and a defect occurs that the surface of the electric wire / cable is easily damaged. Furthermore, this wire / cable has a disadvantage that a whitening phenomenon occurs in which the coating layer portion becomes white when bent, and the wire / cable is melted when exposed to an environment of 130 ° C. or higher. The present invention solves these problems, and in use, while having high flame retardancy and excellent mechanical properties, has extremely high heat resistance and low temperature properties, has excellent flexibility, Provide an insulated wire that is hard to whiten when folded and can be colored in any color, and that does not elute heavy metal compounds, generate large amounts of smoke or corrosive gas during disposal, such as landfilling or burning. It is the purpose.

[0007]

In order to achieve the above object, the present invention provides a primary coating layer made of a flame-retardant resin composition provided around a conductor, and a primary coating layer provided around the primary coating layer. In an insulated wire having a secondary coating layer made of a flame-retardant resin composition, the primary coating layer is composed of 75 to 100% by weight of ethylene / vinyl acetate copolymer and / or ethylene / ethyl acrylate copolymer and 0 to 25% by weight of polyethylene. Base resin 1 consisting of a modified polyethylene resin modified with an unsaturated carboxylic acid or a derivative thereof and 0 to 25 wt%
90 to 135 parts by weight of metal hydrate, based on 00 parts by weight,
7 to 14 parts by weight of red phosphorus, 1 to 10 phenolic antioxidants
The secondary coating layer comprises an ethylene / vinyl acetate copolymer and / or MFR having an MFR of 3 to 28 g / 10 min and a vinyl acetate content of 14 to 30 wt%. Is 3 ~ 28g / 10min
Ethylene acrylate copolymer 75 to 100 wt% with an ethyl acrylate content of 14 to 30 wt%
And modified polyethylene resin 0 to 25 modified with 0 to 25 wt% of polyethylene and unsaturated carboxylic acid or derivative thereof
a flame-retardant resin composition in which 25 to 80 parts by weight of an ammonium polyphosphate-based flame retardant and 1 to 10 parts by weight of a phenolic antioxidant are blended with respect to 100 parts by weight of a second base resin consisting of wt. When the volumes occupied by the primary coating layer and the secondary coating layer are Va and Vb, respectively, the insulated wire is constituted by a volume ratio of Va / Vb ≧ 2.8, and each coating layer is cross-linked. , To provide.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a schematic cross-sectional view showing one embodiment of an insulated wire 1 of the present invention. Reference numeral 2 denotes a single wire or a stranded wire conductor, on which a first base resin has a predetermined amount of metal hydrate and red phosphorus. And a primary coating layer 3 made of a flame-retardant resin composition containing a phenolic antioxidant, and further, a predetermined amount of an ammonium polyphosphate-based flame retardant and a phenolic antioxidant on a second base resin. Is provided with a secondary coating layer 4 made of a flame-retardant resin composition containing The primary coating layer 3 and the secondary coating layer 4 may be successively extrusion-coated on the conductor 2 or may be extrusion-coated simultaneously.

The flame-retardant resin composition constituting the primary coating layer and the secondary coating layer in the insulated wire of the present invention is as follows. (1) The ethylene / vinyl acetate copolymer and the ethylene / ethyl acrylate copolymer used in the first base resin of the primary coating layer of the ethylene / vinyl acetate copolymer and the ethylene / ethyl acrylate copolymer are not particularly limited. The content of vinyl acetate (VA) in the ethylene-vinyl acetate copolymer and the content of ethyl acrylate (EA) in the ethylene-ethyl acrylate copolymer are preferably about 14 to 30% by weight. If the content is less than 14 wt%, there is a problem in flame retardancy, and the whitening characteristics when the above-described electric wire is bent may be deteriorated. If the content exceeds 30 wt%, the flexibility of the coating layer itself becomes too large. It is. The ethylene / vinyl acetate copolymer and the ethylene / ethyl acrylate copolymer used for the second base resin of the secondary coating layer have a VA or EA content of 14 to 30% by weight, similarly to the first base resin.
And one having an MFR specified by ASTM D1238 of 3 to 28 g / 10 min. VA or E
When the content of A is 14 wt% or less, a problem occurs in flame retardancy,
This is because the whitening characteristics are deteriorated, and if it exceeds 30 wt%, the surface of the insulating layer is easily damaged and the strength is also lowered. When the MFR is less than 3 g / 10 min, not only the appearance of the electric wire is remarkably deteriorated, but also the surface is easily damaged, and the low-temperature characteristics are also deteriorated. MFR is 28g / 1
When the time exceeds 0 min, not only the low temperature characteristics are lowered but also the mechanical strength is lowered. In the present invention, an ethylene / vinyl acetate copolymer and / or an ethylene / ethyl acrylate copolymer may be used alone or in combination of two or more. Means that you may. Ethylene-vinyl acetate copolymer and / or ethylene-ethyl acrylate copolymer alone (1
(00%) may be used as a base resin, and the following resin may be blended in an amount of 25% by weight or less in total. That is, the blending amount of the ethylene / vinyl acetate copolymer and / or the ethylene / ethyl acrylate copolymer is 75 wt% or more in order to secure the flame retardancy. This is because it is not possible to obtain the vertical flame retardancy that passes.

(2) Polyethylene The polyethylene used in the present invention includes low density (LD), linear low density (LLD), and ultra low density (VL).
D), medium density (MD), high density (HD) polyethylene (PE) and the like. These polyethylenes may be used singly or as a mixture of two or more. The amount of this polyethylene to be mixed with the above-mentioned ethylene / vinyl acetate copolymer and / or ethylene / ethyl acrylate copolymer is 0 to 25% by weight. The reason for blending polyethylene is to improve the strength of the coating layer. However, blending 25 wt% or more is not preferable because flame retardancy is reduced. (3) Polyolefin resin modified with unsaturated carboxylic acid or derivative thereof As the polyolefin resin modified with unsaturated carboxylic acid or derivative thereof used in the present invention, LLDPE or LDPE modified with maleic acid is preferable. is there. The amount of the polyolefin resin modified with the unsaturated carboxylic acid or derivative thereof to be mixed with the above-mentioned ethylene / vinyl acetate copolymer and / or ethylene / ethyl acrylate copolymer is 0 to 25%. The reason for blending this kind of polyolefin resin is to alleviate a decrease in mechanical strength of the coating layer when a metal hydrate or an ammonium polyphosphate flame retardant described later is blended, and to improve the strength of the coating layer. However, if more than 25 wt% is blended,
It is not preferable because it reduces the flame retardancy.

(4) Metal Hydrate The metal hydrate used in the present invention is not particularly limited. Examples thereof include aluminum hydroxide, magnesium hydroxide, aluminum silicate hydrate, magnesium silicate hydrate, and basic hydrate. Compounds having a hydroxyl group or water of crystallization such as magnesium carbonate and hydrotalcite can be used alone or in combination of two or more. The blending amount of the metal hydrate in the primary coating layer is as follows:
The amount is 90 to 135 parts by weight, preferably 95 to 125 parts by weight based on 00 parts by weight. If the amount of the metal hydrate is less than 90 parts by weight, it is not possible to impart sufficient flame retardancy as a coating material for an insulated wire used in electric / electronic equipment. Exceeding this is undesirable because mechanical properties such as tensile strength and tensile elongation decrease. The reason why the metal hydrate is blended in a larger amount than in the conventional example is to leave the mechanical strength to the secondary coating layer and to emphasize the flame retardancy. These metal hydrates are obtained by subjecting magnesium hydroxide to a surface treatment, for example, “Kisma 5”.
(Manufactured by Kyowa Chemical Industry Co., Ltd.), and particularly “Kisma 5
Grades such as A, Kisuma 5B, Kisuma 5E, and Kisuma 5J are preferred.

(5) Red phosphorus In the present invention, red phosphorus is blended in the primary coating layer for the purpose of improving the flame retardancy of the insulated wire. Red phosphorus is added only to the primary coating layer, and the amount is 7 to 14 parts by weight, preferably 9 to 13 parts by weight based on 100 parts by weight of the first base resin. If the amount of red phosphorus is less than 7 parts by weight, the coating material does not have sufficient vertical flame retardancy as an insulated wire used for electric and electronic equipment,
When the amount exceeds 14 parts by weight, mechanical properties such as tensile strength and tensile elongation are deteriorated. Further, with respect to red phosphorus, heat- and moisture-resistant and dispersibility in the resin composition are preferably subjected to a surface treatment, and furthermore, suppression of deterioration in physical properties of the resin composition and improvement of flame retardancy are performed. In view of this, the average particle size is preferably 10 μm or less, particularly preferably 7 μm or less, and the shape is preferably spherical. Commercial products of such products include "NOVA Red", "NOVA EXCEL", and "NOVA QUEL" (manufactured by Rin Kagaku Kogyo KK).

(6) Ammonium polyphosphate-based flame retardant In the present invention, polyphosphoric acid is added to the secondary coating layer of the insulated wire so that the secondary coating layer is colored to an arbitrary color while imparting flame retardancy. An ammonium-based flame retardant is blended. Examples of the ammonium polyphosphate-based flame retardant include those containing ammonium polyphosphate alone, those containing isocyanuric acid or a derivative thereof, and those coated with a melamine / formaldehyde resin. Ammonium polyphosphate containing isocyanuric acid or a derivative thereof is a material suitable for improving the flame retardancy of an insulated wire. Among them, tris (2-hydroxyethyl) isocyanurate has an affinity with a polyolefin resin and flame retardancy. It is preferable from the viewpoint of improving the properties. Ammonium polyphosphate coated with a melamine / formaldehyde resin or the like can improve the flame retardancy and improve the water resistance of the insulated wire. As such, "Hostafram AP42
2) “Hostafram AP423” “Hostafram AP4”
62, "Hostafram AP745" (manufactured by Hoechst), "Sumisafe P", "Sumisafe PM" (manufactured by Sumitomo Chemical), "Terage" (manufactured by Chisso), and the like. The compounding amount of the ammonium polyphosphate-based flame retardant is 25 to 80 parts by weight, preferably 40 to 75 parts by weight based on 100 parts by weight of the second base resin. If the amount of the ammonium polyphosphate-based flame retardant is less than 25 parts by weight, the insulating material does not have sufficient vertical flame retardancy as an insulated wire used for electric and electronic equipment. This is not preferable because mechanical properties such as tensile elongation and abrasion resistance decrease.

(7) Phenolic antioxidant In the present invention, a phenolic antioxidant is added to improve heat resistance and flame retardancy. As phenolic antioxidants, pentaerythrityl-tetrakis (3- (3,
5-di-t-butyl-4-hydroxyphenyl) propionate), octadecyl (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate),
1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene and the like. The phenolic antioxidant content is the first
The amount is 1 to 10 parts by weight based on 100 parts by weight of each of the base resin and the second base resin. If the compounding amount is less than 1 part by weight, the heat resistance and flame retardancy of the coating layer cannot be sufficiently improved, and if it exceeds 10 parts by weight, the flame retardancy decreases, causing bleeding on the surface of the electric wire and crosslinking of the base resin. It is not preferable because it lowers the efficiency. The flame retardant resin composition for forming the secondary coating layer of the insulated wire of the present invention does not contain red phosphorus, but contains an ammonium polyphosphate-based flame retardant and a phenolic antioxidant. The layer is white, and therefore, can be easily colored to any color by blending the resin composition with a colorant or a color batch containing a polyolefin-based resin as a base resin.

In the present invention, the resin composition for forming the primary coating layer and the secondary coating layer of the insulated wire includes various additives generally used in wires and cables, for example, an antioxidant. In addition, a metal deactivator, a flame retardant (auxiliary) agent, a filler, a lubricant and the like can be appropriately compounded within a range that does not impair the object of the present invention. As an antioxidant, 4,4′-dioctyl diphenylamine, N, N′-diphenyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline can be used in combination with a phenolic antioxidant. Amine-based antioxidants such as polymers of bis (2-methyl-4- (3-n-alkylthiopropionyloxy) -5-t-butylphenyl) sulfide, 2-mercaptobenzimidazole and zinc salts thereof, pentane And sulfur-based antioxidants such as erythritol-tetrakis (3-lauryl-thiopropionate). As the metal deactivator, N, N'-bis (3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionyl) hydrazine, 3- (N-salicyloyl)
Amino-1,2,4-triazole, 2,2′-oxamidobis- (ethyl 3- (3,5-di-tert-butyl-4)
-Hydroxyphenyl) propionate) and the like.

As the 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 , Zinc borate, white carbon, and the like. Particularly, "SFR-100" (General El
ectric), "Trefill E", "Trefill F", "Trefill R" (Dow Corning Toray)
Silicone compounds such as these are effective in improving the flame retardant effect of metal hydrate, red phosphorus, and ammonium polyphosphate flame retardants. As lubricants, hydrocarbons, fatty acids,
Fatty acid amide type, ester type, alcohol type, metal soap type and the like can be mentioned. Among them, ester type lubricants such as "wax E" and "wax OP" (manufactured by Hoechst) which simultaneously exhibit internal lubrication and external lubrication are exemplified. preferable.

In the insulated wire of the present invention, the coating layer is crosslinked for the purpose of improving heat resistance. As a crosslinking method, an electron beam crosslinking method or a chemical crosslinking method can be adopted.
In the case of the electron beam crosslinking method, crosslinking is performed by irradiating an electron beam after coating the flame-retardant resin composition constituting the primary coating layer and the secondary coating layer by extrusion molding. The dose of electron beam is 1-30
Mrad is appropriate, and in order to carry out crosslinking efficiently, the flame retardant resin composition constituting the primary coating layer and the secondary coating layer is added to a methacrylate compound such as trimethylolpropane triacrylate or an allyl such as triallyl cyanurate. It is preferable to blend a polyfunctional compound such as a compound, a maleimide compound or a divinyl compound as a crosslinking aid. In the case of the chemical crosslinking method, an organic peroxide such as a hydroperoxide, a dialkyl peroxide, a diacyl peroxide, a peroxyester, a ketone peroxyester, and a ketone peroxide is added to the flame-retardant resin composition constituting the primary coating layer and the secondary coating layer. It is compounded as a cross-linking agent and cross-linked by heat treatment after extrusion molding coating.

In the insulated wire according to the present invention, assuming that the volume occupied by the primary coating layer is Va and the volume occupied by the secondary coating layer is Vb, the primary coating layer has a ratio satisfying a volume ratio of Va / Vb ≧ 2.8. And a secondary coating layer. If Va / Vb is smaller than 2.8, the flame retardancy is reduced, and the desired vertical flame retardancy cannot be obtained. The thickness of the secondary coating layer is not particularly limited.
When the thickness is less than m, coloring becomes extremely difficult.
Preferably, the thickness is at least m. In some cases, the primary coating layer is made of highly insulated wires by blending metal hydrate, red phosphorus and a phenolic antioxidant with the first base resin, even if the mechanical strength of the primary coating layer is slightly sacrificed. The flame retardancy is imparted, and the secondary coating layer supplements the mechanical weakness of the primary coating layer and burns the insulated wires by blending the ammonium polyphosphate flame retardant and the phenolic antioxidant in the second base resin. Occasionally a strong shell (the surface is carbonized at the initial stage of combustion to block oxygen to the inside and burn out but does not fall) enables coloring and printing without reducing the flame retardancy of the insulated wire Things. In addition,
An intermediate layer may be provided between the primary coating layer and the secondary coating layer as long as the characteristics of the present invention are not impaired.

[0019]

EXAMPLES The components of Examples 1 to 14 shown in Tables 1 to 3 were dry-blended at room temperature and melted and kneaded using a Banbury mixer to obtain a flame-retardant resin composition for a primary coating layer and a secondary coating. Each of the flame-retardant resin compositions was prepared. Next, a conductor (conductor diameter: 0.95 m) was used using an extrusion coating apparatus for manufacturing an electric wire.
mφ tinned soft copper stranded wire Composition: 21 wires / 0.18mm
φ) On the above, the above-mentioned resin composition for the primary coating and the resin composition for the secondary coating layer, which were previously melt-kneaded, were coated to the respective thicknesses shown in Tables 1 to 3 by simultaneous extrusion, corresponding to each Example. Insulated wires were manufactured. For each insulated wire obtained,
The appearance, elongation, tensile strength, heat deformability, flame retardancy, low temperature properties, whitening properties, flexibility, and color appearance were evaluated, and the results are shown in Tables 1 to 3.

[0020]

COMPARATIVE EXAMPLE The components of Comparative Examples 1 to 13 shown in Tables 4 to 6 were melt-kneaded in the same manner as in the Examples, and were extruded and coated on conductors to produce insulated wires corresponding to the Comparative Examples. The same evaluation as in the example was performed for each insulated wire, and the results are shown in Tables 4 to 6. The evaluation test was performed and evaluated as follows. The appearance was evaluated by observing the appearance of the completed insulated wire, and evaluated as ○ when satisfied, × when scratched or rough on the surface, and Δ when judged to be slightly defective. The elongation (%) and tensile strength (MPa) were measured under the conditions of a mark length of 25 mm and a tensile speed of 500 mm / min. As for the heat deformability, a heat deformation test specified in UL1581 was performed at 180 ° C., and the deformation rate was evaluated in%. Flame retardancy was measured for each insulated wire by the vertical combustion test method specified in UL1581. The low-temperature property was wound at its own diameter at −30 ° C., and it was confirmed whether or not cracks occurred in the insulating portion. Whitening is the same part of the wire 3
It was folded twice and the degree of whitening was judged as ○, Δ, ×. The flexibility was evaluated by wrapping it around a mandrel having a diameter of 50 mm 10 times and evaluating the easiness of wrapping. The color appearance was evaluated by observing the color of the surface of the insulated wire, and was evaluated as ○ when sufficient coloring or printing was possible, and x when insufficient.

The components shown in Tables 1 to 6 were as follows. (01) Ethylene / vinyl acetate copolymer (EVA) manufactured by DuPont-Mitsui Polychemicals Co., Ltd. Product name: V-527-
4 VA content 17 wt%, MFR = 0.8 g / 10 min (02) Ethylene-vinyl acetate copolymer (EVA) manufactured by Du Pont-Mitsui Polychemicals Co., Ltd. Product name: EV-450 VA content 19 wt%, MFR = 15 g / 10 min (03) Ethylene / ethyl acrylate (EEA) Product name: NUC6510 EA content 25%, manufactured by Nippon Unicar (04) Ethylene / vinyl acetate copolymer (EVA) Product name: EV-460 VA manufactured by DuPont Mitsui Polychemicals Content: 19 wt%, MFR = 2.5 g / 10 min (05) Medium-density polyethylene / ethylene copolymer manufactured by Ube Industries, Ltd. Product name UBEC-180 (06) Modified polyethylene manufactured by Nippon Petrochemical Company N-polymer L6100M (07) Magnesium hydroxide Kyowa Chemical Co., Ltd. Product name: Kisuma 5J

(08) Red phosphorus, manufactured by Rin Kagaku Kogyo Co., Ltd .: Nova Excel F5 (average particle size: 5 μm) (09) Red Rin Rin Kagaku Co., Ltd., product name: Nova Red 120UF (average particle size: 10 μm) (10) Ammonium polyphosphate flame retardant manufactured by Chisso Co., Ltd. Trade name: Terage C-60 (11) Phenol antioxidant manufactured by Ciba-Geigy Co., Ltd. Trade name: Irganox M
D1024 (12) Phenol antioxidant Ciba-Geigy, Inc. Trade name: Irganox M
D1010 (13) Lubricant Product name: Wax OP (14) Color masterbatch for coloring Product name: PEM521 (15) Cross-linking aid Product name: Ogmont-200 (16) ) Antioxidant Product name: Nouchikku MBZ manufactured by Ouchi Shiko Chemical Co., Ltd. (17) Titanium oxide Product name: CR-60 manufactured by Dainichi Seika Kogyo Co., Ltd.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

From the results shown in Tables 1 to 3, the primary coating layer is composed of only the ethylene / vinyl acetate copolymer, and the ethylene / vinyl acetate copolymer is mixed with polyethylene or modified polyethylene within the scope of the present invention (hereinafter referred to as an appropriate amount). Flame-retardant resin composition obtained by blending an appropriate amount of modified polyethylene with an ethylene / ethyl acrylate copolymer as a first base resin and blending an appropriate amount of a metal hydrate, red phosphorus, and a phenolic antioxidant therewith. The secondary coating layer is composed of a flame retardant resin composition in which an ethylene-vinyl acetate copolymer having an appropriate MFR, vinyl acetate content, and an appropriate amount of an ammonium polyphosphate-based flame retardant and a phenolic antioxidant are blended. Each insulated wire obtained by adjusting the volume occupied by the primary coating layer and the secondary coating layer, that is, the volume ratio of Va / Vb, has the appearance, elongation, tensile strength, Deformation resistance, flame retardance, low temperature characteristics, whitening resistance, was intended to satisfy flexibility, all color appearance. On the other hand, Comparative Examples 1 and 2, in which the amount of metal hydrate was not appropriate, and Comparative Examples 3, 4, in which the amount of red phosphorus was not appropriate, had poor flame retardancy or whitening properties, and had an antioxidant. (Comparative Examples 5 and 6), the flame retardancy is poor. MFR and VA of base resin for secondary coating layer
Comparative Examples 7, 8, and 9 in which the content is out of the appropriate values have difficulty in appearance, low-temperature characteristics, and whitening properties, and Comparative Examples 10 and 11 in which the amount of ammonium polyphosphate is not an appropriate amount have poor flame retardancy and whitening properties. However, Comparative Example 12 in which the composition of the base resin of the primary coating layer is not appropriate has difficulty in flame retardancy, and Comparative Example 13 in which the volume ratio of Va / Vb is not appropriate has a problem in flame retardancy.

As can be seen from the above Examples and Comparative Examples, the composition of the first base resin constituting the primary coating layer and the amounts of the metal hydrate, red phosphorus and phenolic antioxidant to be added thereto are properly adjusted. The composition of the second base resin constituting the secondary coating layer, the amount of ammonium polyphosphate and the amount of the phenolic antioxidant to be added thereto are appropriately selected, and Va / Vb is selected.
By adjusting the volume ratio of the insulated wire, the appearance, elongation,
A flame-retardant insulated wire satisfying all of tensile strength, heat deformability, flame retardancy, low-temperature characteristics, whitening property, flexibility, and color appearance can be obtained.

[0031]

According to the insulated wire of the present invention, the primary coating layer is composed of a highly flame-retardant material composed of metal hydrate, red phosphorus and a phenolic antioxidant, and the secondary coating layer is blended with red phosphorus. It has high flame retardancy and excellent low-temperature properties and heat resistance because it is composed of a white flame retardant material composed of ammonium polyphosphate flame retardant and a phenolic antioxidant. Excellent in mechanical properties such as flexibility and whitening property,
By performing arbitrary printing or coloring on the secondary coating layer, an excellent identification function can be imparted. In addition, by properly selecting the volume ratio between the primary coating layer and the secondary coating layer, the insulated wire of the present invention can further improve the flame retardancy. Furthermore, the insulated wire according to the present invention has a primary coating layer and a secondary coating layer formed of a non-halogen flame-retardant material and does not contain heavy metals. No smoke, no corrosive gas,
It is very effective as a wiring material for electric and electronic devices in consideration of environmental issues, and has excellent industrial effects.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the insulated wire of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulated wire 2 Conductor 3 Primary coating layer 4 Secondary coating layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C08L 23/08 C08L 23/08 31/04 31/04 S 33/06 33/06

Claims (1)

[Claims] An insulated wire having a primary coating layer made of a flame-retardant resin composition provided around a conductor and a secondary coating layer made of a flame-retardant resin composition provided around the primary coating layer. In the above, the primary coating layer is a modified polyethylene resin modified with 75 to 100% by weight of an ethylene / vinyl acetate copolymer and / or an ethylene / ethyl acrylate copolymer, 0 to 25% by weight of polyethylene, and an unsaturated carboxylic acid or a derivative thereof. 90 to 135 parts by weight of a metal hydrate, 7 to 14 parts by weight of red phosphorus, and phenolic antioxidant 1 to 100 parts by weight of a first base resin consisting of
The secondary coating layer is composed of an ethylene / vinyl acetate copolymer having an MFR of 3 to 28 g / 10 min and a vinyl acetate content of 14 to 30 wt% and / or 10 parts by weight of the flame retardant resin composition. MFR is 3-28g / 10m
ethylene-ethyl acrylate copolymer 75-100 w in which the content of ethyl acrylate is 14-30 wt%
t%, 0-25 wt% of polyethylene and a modified polyethylene resin 0 modified with an unsaturated carboxylic acid or a derivative thereof.
A flame-retardant resin composition comprising 25 to 80 parts by weight of an ammonium polyphosphate-based flame retardant and 1 to 10 parts by weight of a phenolic antioxidant with respect to 100 parts by weight of a second base resin comprising 25 wt%; When the volumes occupied by the primary coating layer and the secondary coating layer are Va and Vb, respectively, the insulated wire is constituted by a volume ratio of Va / Vb ≧ 2.8, and each coating layer is cross-linked. .