JPH11339563A - Flame retardant wire and cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame retardant wire and cable having excellent characteristics by providing flame resistance suitable for an insulating material of the wire and cable without degrading mechanical characteristics and workability of a polyolefin resin. SOLUTION: These flame retardant wire and cable are composed by using a flame retardant resin composition prepared by compounding 20-150 pts.wt. of a metal hydroxide flame retarder and 1-2 pts.wt. of phosphorous ester selected from pentaerythritol diphosphite and 2-methylene bisaryl phosphite per 100 pts.wt. of a polyolefin resin for an inclusion material on a sheath material, an insulation material, sheath and insulating materials, or a stranded core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant electric wire and a flame-retardant cable using a novel flame-retardant resin composition for a sheath and an insulator.

[0002]

2. Description of the Related Art In general, polyolefin resins are frequently used as insulating materials for electric wires and cables. When flame-retarding this polyolefin resin, a halogen-based flame retardant containing bromine, chlorine and the like is added. Or a method of adding a metal hydroxide as a halogen-free flame retardant.

[0003]

However, when a halogen-based flame retardant is used, there is a problem that a toxic or corrosive gas may be generated when burned. On the other hand, when non-halogen metal hydroxide is used, no toxic or corrosive gas is generated during combustion, but in order to satisfy the flame retardancy required for electric wires and cables, a large amount of metal is used for polyolefin resin. It is necessary to add hydroxide. Then, by adding a large amount of metal hydroxide, there is a problem in that the mechanical properties inherent to the polyolefin-based resin are reduced, and the extrusion processability is also reduced.

[0004] The present invention has been made in view of the above-mentioned circumstances, and it is possible to obtain a preferable flame retardancy as an insulating material for electric wires and cables without impairing the mechanical properties and workability of the polyolefin resin. An object is to provide excellent flame-retardant electric wires and cables.

[0005]

The object of the present invention is to provide a metal hydroxide flame retardant of 20 to 150 parts by weight, pentaerythritol diphosphite and 2,2-methylenebisaryl based on 100 parts by weight of a polyolefin resin. The problem can be solved by using a flame-retardant resin composition containing 1 to 20 parts by weight of a phosphite selected from phosphites. The flame-retardant resin composition can be preferably used as a sheath material, an insulator material, a sheath material and an insulator material of an electric wire / cable, or an inclusion material on a stranded core wire.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The flame-retardant electric wire and the flame-retardant cable of the present invention are obtained by mixing a flame-retardant resin composition obtained by blending a metal hydroxide flame retardant and a specific phosphite into a polyolefin-based resin. Used for the sheath material, the insulator material, the sheath material and the insulator material, or the inclusion material on the twisted core wire.

As the polyolefin resin, for example,
Polyethylene (PE) such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), and polypropylene (PP) , Ethylene-propylene copolymer (EPM), particularly ethylene-ethyl acrylate copolymer (EEA), ethylene-vinyl acetate copolymer (EV)
A), an ethylene- (meth) acrylate copolymer,
Olefin copolymers and the like can be preferably used.

As the metal hydroxide flame retardant, magnesium hydroxide (Mg (OH) ₂ ), aluminum hydroxide, hydrotalcite and the like are used, and magnesium hydroxide (Mg (OH) ₂ ) is particularly preferably used. . These flame retardants decompose into oxides and water vapor by an endothermic reaction during combustion to exhibit flame retardancy. For example, when magnesium hydroxide (Mg (OH) ₂ ) is added to a polyolefin-based resin, water is lost during combustion. Magnesium oxide decomposes into oxides and water vapor, thereby lowering the temperature and suppressing the supply of oxygen to the burning part with the generated water vapor. Further, it is possible to prevent the flame from spreading to a new resin surface due to the attachment of the oxide to the burned portion.

In the present invention, a specific phosphite, that is, pentaerythritol diphosphite or 2,2-methylenebisaryl phosphite is used together with the metal hydroxide flame retardant. Pentaerythritol diphosphite is represented by the following general formula (I).

Embedded image Here, R ₁ and R ₂ are the same or different hydrocarbon groups, such as an alkyl group such as methyl, ethyl, butyl and octyl, a cycloalkyl group such as cyclohexyl and 4-methylcyclohexyl, phenyl and 2-tert-butyl. Phenyl, 2,4-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2-tert-butyl-4-methylphenyl, 2,4-di-tert-butyl-6-methylphenyl, 2,
6-ditert-butyl-4-methylphenyl, 2,4,6-
An aryl group such as tridi-tert-butylphenyl and 2-tert-amyl-4-methylphenyl can be exemplified. Of these, those in which R ₁ and R ₂ are both aryl groups, and particularly those having one or more tertiary alkyl group-substituted phenyl groups are preferred.

As pentaerythritol diphosphite, more specifically, diphenylpentaerythritol diphosphite, di-p-tolylpentaerythritol diphosphite, dioleyl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, Di-2,4-xylenylpentaerythritol diphosphite, di- (2-tert-butylphenyl) pentaerythritol diphosphite, di- (4-tert-butylphenyl) pentaerythritol diphosphite,
Di- (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, di- (2-tert-butyl-4-)
Methylphenyl) pentaerythritol diphosphite, di- (2-tert-amyl-4-methylphenyl) pentaerythritol diphosphite, di- (2-tert-butyl-5-methylphenyl) pentaerythritol diphosphite, di- -(2-tert-amyl-5-methylphenyl) pentaerythritol diphosphite, di- (2-
Tert-butyl-4-diphenyl) pentaerythritol diphosphite, di- (2,4-di-tert-amylphenyl) pentaerythritol diphosphite, di- (2
4-dimethyl-6-tert-butylphenyl) pentaerythritol diphosphite, di- (2-methyl-4,6-
Di-tert-butylphenyl) pentaerythritol diphosphite, di- (2-tert-butyl-4-cyclohexylphenyl) pentaerythritol diphosphite, and the like.

The 2,2-methylenebisaryl phosphite is represented by the following general formula (II).

Embedded image Here, R ₃ is an alkyl group such as methyl, ethyl, propyl, butyl, octyl, decyl, myristyl, palmityl, and stearyl, a cycloalkyl group such as cyclohexyl, and an aryl group such as phenyl and tolyl. R ₄ and R _{5 each} represent one or more alkyl groups, for example, 4-methyl, 6-methyl, 4-tert-butyl, 6-tert-butyl, 4-methyl-6-tert-butyl,
4,6-di-tert-butyl, 4,6-di-tert-amyl and the like. Of these, R ₄ and R ₅ are preferably those of a 4,6-ditertiary alkyl group.

More specifically, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, 2,2-methylene bis (4-methyl-6-tert-butylphenyl) octyl phosphite 2,2-methylenebis (6-methyl-4-tert-butylphenyl) octyl phosphite, 2,2-methylenebis (4,6-di-
Tert-butylphenyl) decyl phosphite, 2,2-methylenebis (4-methyl-6-tert-butylphenyl) dodecyl phosphite, 2,2-methylenebis (6-methyl-4-tert-butylphenyl) hexyl phosphite ,
2,2-methylenebis (4,6-di-tert-amylphenyl) decyl phosphite and the like can be exemplified.

In the present invention, the amounts of the metal hydroxide flame retardant and the phosphite are slightly different depending on the kind of the polyolefin resin used. 20 to 150 parts by weight of a substance flame retardant and 1 to 2 phosphites
A range of 0 parts by weight is preferred. If the amount of the metal hydroxide flame retardant is too small, favorable flame retardancy cannot be obtained. If the amount is too large, the mechanical strength of the flame retardant resin composition is significantly deteriorated, which is not preferable for electric wires and cables. If the amount of the phosphite is too small, favorable flame retardancy cannot be obtained. If the amount is too large, the mechanical strength of the flame-retardant resin composition is poor.

In addition to the above-mentioned compounding agents, various additives such as ultraviolet absorbers, antioxidants, antioxidants, copper damage inhibitors, pigments, dyes and other coloring agents, and small amounts of inorganic fine powder such as talc. Additives can be appropriately compounded. In particular, when an antioxidant, particularly a phenolic antioxidant is added, the flame retardant effect may be improved. In selecting the additives, those containing no halogen and especially lead (Pb) are preferable for the incineration treatment and landfill treatment of electric wires and cables. Further, it is preferable that the harmful heavy metal such as cadmium (Cd) is not contained as much as possible, and it is preferable that the content of the harmful heavy metal in the flame retardant resin composition is suppressed to less than 0.1% by weight.

The flame-retardant electric wire / cable of the present invention uses the above-mentioned flame-retardant resin composition as a sheath material, an insulator material, a sheath material and an insulator material, or an interposer material on a stranded core wire. The structure is appropriately designed according to the application. Generally, in the case of a cable, only the sheath is often formed of a flame-retardant resin composition. If necessary, the flame-retardant resin composition may be mixed with a pigment or the like to be colored. Using this, the insulator or the sheath may be formed of a colored resin layer.

In the present invention, depending on the use of the electric wire or cable, an appropriate foaming agent may be added in advance to the flame-retardant resin composition, and foamed at the time of producing the electric wire or cable. In this case, the degree of foaming is preferably in the range of less than 10%. Further, when an insulator is formed from the above flame-retardant resin composition, the volume resistivity is set to 1 × 10 ¹³ (Ω ·
cm) or more. Further, in the present invention, the specific gravity of the flame-retardant resin composition is more preferably 1.14 or less. In particular, in the present invention, by adding a phosphite, the amount of the metal hydroxide flame retardant having a relatively large specific gravity can be reduced, so that a flame-retardant resin composition having a low specific gravity is realized. Is possible. If the specific gravity of the flame-retardant resin composition used in the present invention is 1.14 or less, the plastic can be separated from polyvinyl chloride (PVC) by specific gravity separation of the plastic using running water.
It is preferable from the viewpoint of treating unnecessary electric wires and cables.

In the flame-retardant electric wire / cable of the present invention using the above-mentioned flame-retardant resin composition, by adding a small amount of the above-mentioned phosphite, the flame-retardant resin composition can be used. Flammability can be greatly improved. Therefore, the compounding amount of the metal hydroxide flame retardant can be reduced as compared with the conventional one, and the preferable flame retardancy as a material for electric wires and cables can be achieved without impairing the mechanical properties and extrusion processability of the polyolefin resin. Is possible. Therefore, according to the present invention, it is possible to obtain a flame-retardant electric wire / cable having an insulator and / or a sheath or an inclusion having excellent self-extinguishing flame retardancy and excellent mechanical properties. Further, since the extrudability of the flame-retardant resin composition used is good, the workability and the yield are good, and the product quality is also excellent. The flame-retardant electric wires and cables obtained in this way are hardly flammable in the event of a fire and emit little smoke. Further, since the insulator material and the sheath material do not contain halogen, they do not generate toxic gas such as dioxin or halogen gas during combustion, can be incinerated, and do not generate toxic gas even at fire.

The flame-retardant electric wires and cables of the present invention include, for example, insulated electric wires, electric equipment wiring electric wires, automobile electric wires, equipment electric wires, power cords, insulated electric wires for outdoor power distribution, electric power cables, and control electric wires. It can be suitably used as a cable, a communication cable, an instrumentation cable, a signal cable, a movement cable, a ship cable, and the like.

[0019]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples. As examples and comparative examples of the present invention,
At a rate shown in Table 1 below, a polyolefin-based resin, a metal hydroxide flame retardant, a phosphite, and an antioxidant were blended to form a mixture. Examples of the polyolefin resin include an ethylene-ethyl acrylate copolymer (ethyl acrylate content 10%; EEA1) and an ethylene-ethyl acrylate copolymer (ethyl acrylate content 20%; EEA)
2), ethylene-vinyl acetate copolymer (vinyl acetate content 10%; EVA1), and polyethylene (PE) were used. Each of these resins has a melt index of 5
Met. Magnesium hydroxide and aluminum hydroxide were used as metal hydroxide flame retardants. As the phosphite, PEP- represented by the following chemical formula (III)
36 (trade name; manufactured by Asahi Denka Co., Ltd.). Further, Irganox # 1010 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was used as an anti-aging agent.

[0020]

Embedded image

The obtained mixture was formed into a sheet having a thickness of 3.0 mm to obtain a sample. The obtained sample was examined for flame retardancy, tensile strength, and elongation at break. Flame retardancy is JIS K
It was evaluated by the oxygen index (OI) according to the test method of 7201. The results are shown in Table 1 below.

[0022]

[Table 1]

[0023]

As described above, the flame-retardant electric wire / cable of the present invention comprises a polyolefin resin having a metal hydroxide and a phosphite ester selected from pentaerythritol diphosphite and 2,2-methylenebisaryl. Is used as a sheath material, an insulator material, a sheath material and an insulator material, or an inclusion material on a stranded core wire. Since this flame-retardant resin composition is provided with excellent flame retardancy without impairing the processability and mechanical properties of the polyolefin resin, electric wires and cables having excellent flame retardancy and mechanical properties Is obtained. Further, since the flame-retardant resin composition of the present invention has good extrusion processability, it has good manufacturing workability, good yield, and good product quality. Furthermore, in addition to the above-mentioned applications, as wire / cable related items, there are also wire / cable accessories such as conduits, pipes, connection parts, sheets, tapes, heat-shrinkable tubes, etc., or components such as connection parts and terminal parts. Applicable.

Claims (4)

[Claims] 1. A metal hydroxide flame retardant of 20 to 150 parts by weight, and a phosphorous acid selected from pentaerythritol diphosphite and 2,2-methylenebisaryl phosphite, based on 100 parts by weight of a polyolefin resin. A flame-retardant electric wire or cable using a flame-retardant resin composition comprising 1 to 20 parts by weight of an ester as a sheath material. 2. A metal hydroxide flame retardant of 20 to 150 parts by weight, and phosphorous acid selected from pentaerythritol diphosphite and 2,2-methylenebisaryl phosphite, based on 100 parts by weight of polyolefin resin. Flame-retardant electric wires and cables using a flame-retardant resin composition comprising 1 to 20 parts by weight of an ester as an insulating material. 3. A metal hydroxide flame retardant in an amount of 20 to 150 parts by weight based on 100 parts by weight of a polyolefin resin, and phosphorous acid selected from pentaerythritol diphosphite and 2,2-methylenebisaryl phosphite. A flame-retardant electric wire or cable using a flame-retardant resin composition comprising 1 to 20 parts by weight of an ester as a sheath material and an insulator material. 4. A phosphoric acid selected from the group consisting of 20 to 150 parts by weight of a metal hydroxide flame retardant and pentaerythritol diphosphite and 2,2-methylenebisaryl phosphite based on 100 parts by weight of a polyolefin resin. A flame-retardant electric wire / cable using a flame-retardant resin composition comprising 1 to 20 parts by weight of an ester as an inclusion material on a twisted core wire of the electric wire / cable.