JP3164485B2 - Insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant insulated wire.

[0002]

2. Description of the Related Art In recent years, with the sophistication and densification of urban functions, power cables and communication cables, as well as various insulated wires used for wiring between devices and wiring inside devices, have been developed.
As the coating material, non-halogen flame-retardant materials that have high flame retardancy and do not generate harmful halogen-based gas during combustion have come to be used from the viewpoint of disaster prevention at the time of fire. Such non-halogen flame retardant materials exhibit flame retardancy by adding a halogen-free flame retardant to the resin. Examples of such a flame retardant include metal hydrates such as magnesium hydroxide and aluminum hydroxide, and examples of the resin include polyethylene, ethylene copolymers, polyolefin resins such as ethylene propylene rubber, and polypropylene. In addition, crosslinked products of these resins are used.

When it is necessary to impart a high degree of flame retardancy to the above-mentioned non-halogen flame-retardant material, a large amount of metal hydrate is added (for example, an amount exceeding 120 parts by weight with respect to 100 parts by weight of resin). Sometimes. However, when the metal hydrate is added in a large amount, there is a problem that the mechanical properties of the flame retardant material deteriorate. Therefore, by blending red phosphorus as a flame retardant, the blending amount of the metal hydrate is reduced to a small amount (for example, 120 parts by weight or less with respect to 100 parts by weight of the resin), and a high flame retardancy and mechanical properties are obtained. An excellent non-halogen flame retardant material has been used. For wires and cables that require such high flame retardancy, for example,
Flame retardancy that passes the vertical tray combustion test specified in IEEE 383 is required.

[0004]

By the way, several kinds of colors (for example, yellow, white, red, green, and blue) are used for the insulating coating material of the insulated wire for the purpose of distinguishing the type of the insulated wire.
May need to be colored. in this case,
By extrusion coating the colored resin composition on the conductor,
Manufactures colored insulated wires.

When a large amount of red phosphorus is added to a resin composition used for an insulating layer in addition to an inorganic flame retardant such as a metal hydrate in order to obtain an insulated wire having a high flame retardancy, the color of the red phosphorus is developed. As a result, a resin composition that can be colored in any color cannot be obtained, and therefore, there has been a problem that it is difficult to produce an insulated wire colored in any color. Further, when the colored resin composition is exposed to sunlight, a fluorescent lamp, or the like, there is a problem related to so-called weather resistance that the properties of the resin composition are impaired. This problem is due to the fact that carbon having a function of improving weather resistance is not added to the resin composition so that the resin composition can be colored in an arbitrary color.

For example, Japanese Patent Application Laid-Open No. 4-368715 discloses that 100 parts by weight of an ethylene copolymer contains 30 to 20 metal hydrates.
An electric wire coated with a resin composition containing at least one of 0 parts by weight and 3 to 50 parts by weight of red phosphorus (excluding carbon) has excellent flame retardancy and is multicolored because it contains no carbon. It is disclosed that conversion is possible.
However, when it contains 3 parts by weight or more of red phosphorus, it is difficult to achieve multicoloring due to the color development of red phosphorus, and when it does not contain red phosphorus, it is difficult to exhibit high flame retardancy. It is.

Japanese Patent Application Laid-Open No. 1-258310 discloses that electric wires and cables have a two-layer structure of an inner layer and an outer layer, wherein the inner layer is made of a flame-retardant resin composition containing red phosphorus, and the outer layer does not contain red phosphorus. Examples of electric wires and cables composed of a resin composition are disclosed. Here, an example is disclosed in which an electric wire or cable using a resin composition containing no red phosphorus in the outer layer does not crack even when used in a cold region. However, since the resin composition of the outer layer does not contain red phosphorus, the flame retardancy of the electric wire / cable is limited. In addition, when the resin composition of the outer layer does not contain carbon or an ultraviolet protection agent, there is a problem that weather resistance is poor.

Further, Japanese Patent Application Laid-Open No. 62-12006 discloses that the cable has a two-layer structure, and the outer layer is made of a so-called engineering plastic (according to the description of the above patent, a "highly functional flame-retardant polymer"). Discloses a polyester-based elastomer, nylon, PEEK, polycarbonate, etc.), and discloses an example of a cable having an inner layer made of an olefin-based resin composition (in some cases, subjected to a flame retardant treatment). However, engineering plastics have drawbacks in that they are more difficult to extrude and are more expensive than olefin resin compositions. Accordingly, an object of the present invention is to provide an insulated wire having high flame retardancy, excellent mechanical properties, and weather resistance, and which can be easily colored into an arbitrary color in order to solve the above-mentioned problems.

[0009]

Means for Solving the Problems In order to achieve the above object, according to the present invention, in an insulated wire having an insulating layer provided on the outer periphery of a conductor, the inner layer of the insulating layer is formed with respect to 100 parts by weight of an olefin resin. 50 to 120 parts by weight of an inorganic flame retardant,
The insulating layer is formed of a resin composition (A) containing 2.5 to 10 parts by weight of red phosphorus, and the outer layer of the insulating layer is made of an ethylene copolymer 70
Up to 99% by weight of unsaturated carboxylic acid or polyethylene in polyethylene
Is a modified polyether obtained by modifying its derivative by a graft reaction.
Relative to styrene 100 parts, 80 to 150 parts by weight of an inorganic flame retardant, is insulated wire, characterized in that the formation of a resin composition containing red phosphorus 0.5-2 parts by weight (B) is provided.

The polyolefin resin in the resin composition A forming the inner layer of the insulating layer includes ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer and ethylene-methyl methacrylate copolymer. Various types of polyethylene, such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene, as the main component, based on at least one ethylene copolymer selected from the group of coalescence And ethylene propylene rubber, ethylene propylene diene terpolymer, polypropylene,
The modified polyolefin is blended in an appropriate amount. In the present invention, the modified polyolefin is a low-density polyethylene, a high-density polyethylene, a linear low-density polyethylene or the like, and an unsaturated carboxylic acid such as acrylic acid, maleic acid, or fumaric acid or a derivative thereof is grafted to the polyethylene. It is a modified one, and particularly preferably a modified one of linear low density polyethylene (ethylene-α-olefin copolymer).

The olefin resin in the resin composition B forming the outer layer of the insulating layer is composed of 80 to 99% by weight of the above ethylene copolymer and unsaturated carboxylic acid in polyethylene.
Modification of acid or its derivatives by graft reaction
An olefin resin composed of a functional polyethylene is used. In the resin composition for forming the outer layer, the blending of the modified polyolefin is indispensable, and by blending this,
Even when red phosphorus is blended, a resin composition having excellent cold resistance can be obtained. Unsaturated carboxylic acids in polyethylene
Or a modified polymer obtained by modifying the derivative by a graft reaction.
If the ethylene content is less than 1% by weight, the cold resistance will be poor, and if it exceeds 20% by weight, the productivity will decrease.

The inorganic flame retardant used in the resin composition forming the inner and outer layers of the insulating layer includes magnesium hydroxide, aluminum hydroxide, hydrotalcite, zinc borate, calcium carbonate, magnesium oxide, molybdenum oxide and antimony oxide. At least one selected from the group of

The amount of the inorganic flame retardant in the resin composition A is preferably 50 to 120 parts by weight. If the amount is less than 50 parts by weight, high flame retardancy cannot be obtained, and if it exceeds 120 parts by weight, mechanical properties such as tensile strength and tensile elongation deteriorate. Further, the blending amount of red phosphorus in the resin composition A is preferably 2.5 to 10 parts by weight. If it is less than 2.5 parts by weight,
High flame retardancy cannot be obtained, and if it exceeds 10 parts by weight, mechanical properties such as tensile strength and tensile elongation are reduced. A particularly preferred blending amount of red phosphorus is 3 to 5 parts by weight.

The compounding amount of the inorganic flame retardant in the resin composition B is preferably 80 to 150 parts by weight. If the amount is less than 80 parts by weight, high flame retardancy cannot be obtained, and if it exceeds 150 parts by weight, mechanical properties such as tensile strength and tensile elongation deteriorate. The amount of red phosphorus in the resin composition B is preferably 0.5 to 2 parts by weight. If the amount is less than 0.5 parts by weight, high flame retardancy as an insulated wire cannot be obtained,
The weather resistance is also poor. If it exceeds 2 parts by weight, it becomes impossible to produce a resin composition colored in an arbitrary color and an insulated wire. A particularly preferred amount of red phosphorus is 1 to 1.5 parts by weight. As the inorganic flame retardant and red phosphorus used in the present invention, those treated with various surface treatment agents are preferably used. Examples of the surface treatment agent include fatty acids such as stearic acid and oleic acid, phosphate esters and the like, and metal salts thereof.

A coloring agent or a color batch can be added to the resin composition B, if necessary. In particular, when a colored insulated wire is manufactured, it is necessary to mix a colorant or a color batch. The amount of the colorant or the color batch is not particularly limited.
Is preferred so as not to significantly reduce the various properties of the resin composition B, for example, it can be 20% by weight or less of the resin composition B. The resin composition A can be blended with carbon black, a colorant, or a color batch, if necessary.

The resin composition A and the resin composition B may contain, in addition to the above components, an antioxidant, a lubricant, an ultraviolet ray protective agent, a copper harm inhibitor, a dispersant, a crosslinking agent, a foaming agent and the like. An agent may be appropriately added. In this case, the additive to be added to the resin composition B is preferably colorless or white.
Regarding the thickness of the inner layer and the outer layer, it is preferable that the thickness of the inner layer is 80 to 95% of the thickness of the insulating layer, and the thickness of the outer layer is 20 to 5% of the thickness of the insulating layer. 80% inner layer thickness
If the thickness is less than 30, sufficient flame retardancy cannot be obtained, and if the thickness of the inner layer exceeds 95%, the thickness of the outer layer becomes thin, so that stable production of an insulated wire becomes impossible. Similarly, if the thickness of the outer layer exceeds 20%, sufficient flame retardancy cannot be obtained,
When the thickness of the outer layer is less than 5%, stable production of an insulated wire becomes impossible and coloring may be insufficient.

[0017]

The insulated wire of the present invention has high flame retardancy and excellent mechanical properties because the resin composition A used in the inner layer is a composition containing both an inorganic flame retardant and red phosphorus. On the other hand, since the resin composition B used in the outer layer has a proper amount of red phosphorus, it is easily colored, and has excellent flame retardancy and weather resistance.

[0018]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

Examples 1 to 7 and Comparative Examples 1 to 9 First, the components shown in Tables 1 and 2 were dry-blended at room temperature and melt-kneaded using a Banbury mixer.
Each of the resin composition A and the resin composition B was prepared. Next, using an extruder for electric wire production, an insulating layer having a two-layer structure consisting of an inner layer and an outer layer was formed on a 5.5 mm ² copper conductor,
Each of the resin compositions A and B previously melt-kneaded was coated by co-extrusion on each of the thicknesses shown in Tables 1 and 2 and coextruded. 9
Was manufactured. FIG. 1 shows the structure of these insulated wires. 1 is a conductor, 2 is an inner layer of the insulating layer, and 3 is an outer layer of the insulating layer.

Each of the obtained insulated wires was subjected to a tensile test,
The cold resistance test, the flame retardancy test, and the appearance were evaluated, and the results are shown in Tables 1 and 2. Tensile test is based on JIS C 300
The measurement was performed in accordance with No. 5, and the breaking strength and the elongation at break were measured.
The cold resistance test was conducted at 50 ° C. in accordance with JIS C 3005.
The test was performed as follows, and the case where there was no broken sample was evaluated as ○, and the case where there was a broken sample was evaluated as x. In addition, the flame retardancy test was conducted by IEEE
Perform the vertical tray combustion test specified in Estd 383,
The damage length was measured. The appearance was mainly determined by observing the color. An electric wire that was sufficiently colored was evaluated as ○, and an electric wire that was insufficient was evaluated as ×.

A 1 mm-thick press sheet was produced from the resin composition B in each of Examples and Comparative Examples shown in Tables 1 and 2, and the sheet was subjected to a weather resistance test. And Table 2 together. The weather resistance test was performed with a weatherometer. The conditions of the weatherometer were rainfall at 63 ° C. for 12 minutes for 60 minutes. After 500 hours of ultraviolet irradiation time, the sample was taken out, a tensile test was performed, the elongation at break was measured, and the residual elongation was calculated based on the initial elongation value.

[0022]

[Table 1]

[0023]

[Table 2]

The following components were used as the components in the resin composition. Resin a: ethylene / ethyl acrylate copolymer (manufactured by Nippon Petrochemical) MFR = 0.8 g / 10 min, EA content = 15 wt% Resin b: ethylene / vinyl acetate copolymer (manufactured by Mitsui DuPont) MFR = 0.7 g / 10 min, EA content = 17 wt% Resin c: maleic anhydride-modified ethylene-butene-1 copolymer (manufactured by Nippon Petrochemical) Antioxidant: Irganox 1010 (manufactured by Ciba Geigy) Coloring batch for coloring: yellow color batch ( Dainichi Seika)

The following can be seen from the results of Tables 1 and 2. First, as for the thickness of the inner layer and the outer layer of the insulating layer, from the comparison between Examples 1 and 2 and Comparative Example 1, if the thickness of the outer layer is less than 5% of the whole insulating layer, a stable thickness is obtained. In addition, the coloring may be insufficient, and the coloring may be insufficient. Also, from the comparison between Example 3 and Comparative Example 2, it is understood that when the thickness of the outer layer exceeds 20% of the entire insulating layer, the flame retardancy is poor. .

From the comparison between the examples and Comparative Examples 3 and 4, the amount of the inorganic flame retardant in the resin composition A for forming the inner layer is less than the range of the present invention. It can be seen that, if too large, both the breaking strength and the elongation in the tensile test are insufficient. From the comparison of Examples 5 and 7 and Comparative Examples 5 and 6, the blending amount of red phosphorus in the resin composition A is less than the range of the present invention, and the flame retardancy is insufficient. It can be seen that both the breaking strength and the elongation are insufficient.

Further, from the comparison of each of Examples and Comparative Examples 7 and 8, the amount of the inorganic flame retardant in the resin composition B forming the outer layer is less than the range of the present invention. It can be seen that, if too large, both the breaking strength and the elongation in the tensile test are insufficient. In addition, the compounding amount of red phosphorus in the resin composition B was determined according to each Example and Comparative Examples 5, 7, and
From the comparison of 8, 9, it can be seen that if the amount is less than the range of the present invention, the flame retardancy is insufficient, and if the amount is too large, any coloring cannot be performed and a desired appearance cannot be obtained.

[0028]

According to the insulated wire of the present invention, since a specific resin composition is used for the inner layer and the outer layer of the insulating layer, it has high flame retardancy, excellent mechanical properties and weather resistance. It can be arbitrarily colored and is extremely useful as a wiring material.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an insulated wire according to the present invention.

[Explanation of symbols]

 1: conductor 2: inner layer of insulating layer 3: outer layer of insulating layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-609 (JP, A) JP-A-3-226918 (JP, A) JP-A-56-93207 (JP, A) 164113 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01B 7/295 C08K 3/20 C08K 3/32 C08L 23/04 H01B 3/44

Claims (2)

(57) [Claims] 1. An insulated wire having an insulating layer provided on the outer periphery of a conductor, wherein the inner layer of the insulating layer is composed of 50 to 120 parts by weight of an inorganic flame retardant, 100 parts by weight of an olefin resin, and 2.
5 to 10 parts by weight of a resin composition A, wherein the outer layer of the insulating layer is 70 to 99% by weight of an ethylene copolymer.
And polyethylene with unsaturated carboxylic acids or their derivatives
Modified polyethylene by graft reaction
An insulated wire comprising a resin composition B containing 80 to 150 parts by weight of an inorganic flame retardant and 0.5 to 2 parts by weight of red phosphorus with respect to 100 parts by weight of an olefin resin comprising 1% by weight. 2. The thickness of the inner layer is 80 to 9 times the thickness of the entire insulating layer.
5%, and the thickness of the outer layer is 5 to 20% of the thickness of the entire insulating layer.
The insulated wire according to claim 1, wherein