JP2991696B1 - Halogen-free flame-retardant resin composition and flame-retardant electric wire / cable using the same - Google Patents

Abstract

The present invention has the same level of flame retardancy as PVC, and can be used as a coating material for flame-retardant electric wires, cables, and the like, and does not generate harmful gases during incineration. P
Provided is a resin composition capable of being separated from VC by specific gravity. SOLUTION: A metal hydroxide and a flame retardant auxiliary are added to a polyolefin resin, and the specific gravity is 1.14.
Below, when the oxygen index is 24 or more and 34 or less, and it is used as a coating material for electric wires, cables or similar products, the JIS
A non-halogen flame-retardant resin composition, which passes a 60 ° inclined combustion test defined in C3005.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention has a flame retardancy equivalent to that of a polyvinyl chloride (PVC) composition and can be used as a coating material for electric wires, cables and the like having flame retardancy. The present invention relates to a flame-retardant resin composition which has a specific gravity lower than that of a PVC composition, can be separated by specific gravity, does not contain halogen, and can be incinerated, and a flame-retardant electric wire / cable using the same.

[0002]

2. Description of the Related Art PVC compositions are widely used in wire coatings, tubes, tapes, packaging materials, building materials, etc. because of their good electrical insulation and self-extinguishing flame retardancy. Incidentally, since the PVC composition contains chlorine (Cl) which is a halogen, a corrosive gas such as HCl or a toxic gas such as dioxin is generated during combustion. Therefore, various PVC
There is a problem that when products become waste, they cannot be incinerated. Therefore, at present, landfill disposal is performed. However, since a Pb-based stabilizer is used as an additive in the PVC composition, there is also a problem that this is eluted into soil and the like, and it is difficult to dispose of it as industrial waste. It has become to.

[0003]

On the other hand, PVC
If a halogen-free polyethylene (PE) or polypropylene (PP) is used as a resin composition instead of
Since no harmful gas is generated during combustion, incineration is possible. However, these halogen-free resin compositions are made of PVC.
However, there is a drawback that the flame retardancy is inferior to the above. For example, the oxygen index (O) which is one of the evaluation scales of the flame retardancy of the resin composition is used.
Comparison of I) shows that the OI of PVC is 23 to 40, while the OI of PE and PP is inferior to about 17 to 19.

While the oxygen index method described above is an effective method for comparing and evaluating the flame retardancy of resin compositions as materials, especially in the field of electric wires and cables, the resin compositions are used for electric wires, As a method for evaluating the flame retardancy of a cable or a similar product in a state of being formed as a coating layer, JI
A 60 ° tilt combustion test has been established in SC3005. Actually, in order to put into practical use a flame-retardant wire or cable using a resin composition having flame retardancy as the outermost coating material, it is required to pass this 60 ° inclined combustion test.

[0005] Usually, in order to impart flame retardancy to a halogen-free resin composition such as PE or PP, a metal hydrate such as Mg (OH) ₂ is added to these. However, in addition to the high specific gravity of metal hydrate, it is necessary to add 80 parts by weight or more of metal hydrate in order to obtain the same flame retardancy as PVC. The resulting flame-retardant resin composition containing no halogen has a specific gravity similar to that of PVC. For this reason,
There was a problem that the specific gravity of a plastic using water as a specific gravity liquid as described below could not be separated. That is, in order to recycle the recovered plastic or to remove PVC that generates dioxin during combustion, the plastic is put into uniformly flowing water, and separated according to the difference in specific gravity of the plastic.
For example, as shown in FIG. 1, olefin-based plastics 1 such as PP and PE have a specific gravity smaller than that of water (specific gravity of about 0.1%).
9) PVC that floats on the water surface and has a higher specific gravity than water
2 (specific gravity: about 1.3) sinks in water. Styrene plastic 3 (specific gravity: about 1.1) has a specific gravity greater than water,
Since it is smaller than PVC2, it follows a sedimentation trajectory different from that of PVC2. As a result, two types of accumulation distribution of styrene plastic 3 and PVC2 are formed at the bottom of the sorting tank. Therefore, by utilizing this characteristic, it is possible to separate the above three types of plastics, but the above-described flame-retardant resin composition containing no halogen and P
Since the specific gravity is almost the same as that of VC, there is an inconvenience that they cannot be separated.

The present invention has been made in view of the above circumstances, and has the same level of flame retardance as PVC, and can be used as a coating material for flame-retardant electric wires, cables, and the like, and can be incinerated. No harmful gas is generated during processing and P
It is an object of the present invention to provide a resin composition capable of being separated from VC by specific gravity and a flame-retardant electric wire / cable using the same.

[0007]

The object of the present invention is to provide a polyolefin resin having a weight ratio of 20 parts by weight to 100 parts by weight of a polyolefin resin.
Or more and less than 50 parts by weight , and 2 parts by weight or less of the flame retardant auxiliary
It has a specific gravity of 1.14 or less, an oxygen index of 24 or more and 34 or less, and is JIS when used as a coating material for electric wires, cables or similar products.
The problem is solved by a non-halogen flame-retardant resin composition characterized by passing a 60 ° inclined combustion test defined in C3005. Alternatively, polyolefin resin 100
20 parts by weight or more and less than 50 parts by weight of metal hydroxide , 0.5 parts by weight or more and less than 2.5 parts by weight of red phosphorus , and
Adding less than 6 parts by weight or more and 1 part by weight of carbon black and
The specific gravity is 1.14 or less, and the oxygen index is 24 or more 3
4 or less, covering material for electric wires, cables or the like
Established in JIS C3005 when used as
Non-halo, characterized by passing the 0 ° inclined combustion test
The problem is solved by a non-flammable resin composition. The flame-retardant electric wire / cable of the present invention uses such a resin composition for electric wire / cable.
It is used as a covering material of a cable or an inclusion material on a stranded core wire.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The present invention makes it possible to simultaneously achieve preferable flame retardancy and low specific gravity by adding a metal hydroxide as a flame retardant to a polyolefin resin containing no halogen and using a flame retardant auxiliary in combination. Things. The flame-retardant resin composition containing no halogen of the present invention (hereinafter referred to as non-halogen flame-retardant resin composition) has a specific gravity of 1.14.
When the non-halogen flame-retardant resin composition is coated on a conductor so that the oxygen index (OI) is 24 or more and 34 or less, the non-halogen flame-retardant resin composition is coated on the outer periphery of the insulated wire core. When coated as a sheath material,
Alternatively, when used as a coating material for similar products of electric wires and cables such as electric conduits, pipes, tubes, tapes, etc., it is prepared so as to pass the 60 ° inclined combustion test established by JIS C3005. When the specific gravity of the non-halogen flame-retardant resin composition is larger than 1.14, it is not preferable because it is difficult to separate the specific gravity from the PVC.
When the OI of the non-halogen flame-retardant resin composition is 24 or more, flame retardancy equivalent to PVC can be obtained. On the other hand, in order to achieve a specific gravity of 1.14 or less, the amount of the flame retardant and the flame retardant auxiliary agent cannot be increased. Therefore, the upper limit of OI of the non-halogen flame-retardant resin composition of the present invention is about 34. .

In the present invention, various polyolefin resins can be used and can be appropriately selected according to the application. For example, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HD
PE), polyethylene (PE) such as linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), polypropylene (PP), ethylene-vinyl acetate copolymer, ethylene- (meth) acrylate copolymer A coalescence, an olefin copolymer or the like can be preferably used.

[0010] The metal hydroxide used in the present invention may be any as long as it decomposes into oxide and water vapor during combustion to exhibit flame retardancy. For example, magnesium hydroxide (Mg (OH)
₂ ) and aluminum hydroxide are preferably used. For example, magnesium hydroxide (Mg
When (OH) ₂ ) is added, magnesium hydroxide is decomposed into an oxide and water vapor during combustion to lower the temperature and suppress the supply of oxygen to the burning part by 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. The addition amount of the metal hydroxide is in the range of 20 parts by weight or more and less than 50 parts by weight based on 100 parts by weight of the polyolefin resin. If the added amount of the metal hydroxide is too small, favorable flame retardancy cannot be obtained, and if it is too large, the specific gravity of the obtained non-halogen flame-retardant resin composition becomes too large, and the specific gravity cannot be separated from PVC. .

As the flame retardant auxiliary, red phosphorus and carbon black are suitable, and these are preferably used in combination. When used together with the metal hydroxide, these flame retardant aids contribute to the improvement of flame retardancy with a small amount of addition. Alternatively, when magnesium hydroxide is used as the metal hydroxide, N, N'-m-phenylenedimaleimide can be preferably used as the flame retardant auxiliary. It has a relatively low density and acts as a cross-linking aid when used in combination with magnesium hydroxide.
(° C. or more) forms a shell-like heat-insulating layer, so that addition of a small amount contributes to improvement in flame retardancy. In the present invention, the flame retardant aid preferably does not contain heavy metals such as Pb.

If the amount of the flame-retardant auxiliary agent is too small, good flame retardancy cannot be achieved, and if it is too large, the specific gravity of the resulting halogen-free flame-retardant resin composition becomes too large, and PVC and PVC are added. Because it becomes impossible to separate the specific gravity of
It is determined so that the target specific gravity and flame retardancy conditions can be simultaneously satisfied. Therefore, the addition amount of the flame retardant auxiliary varies depending on the type of the flame retardant auxiliary and the combination of the flame retardant and the flame retardant auxiliary used together. A range of less than parts by weight is preferred. Specifically, for example, red phosphorus and carbon black can be preferably used in combination as a flame retardant auxiliary. In this case, the addition amount of red phosphorus is 0.5 part by weight based on 100 parts by weight of the polyolefin resin. It is preferable that the amount is not less than 2.5 parts by weight and the amount of carbon black added is not less than 1 part by weight and less than 6 parts by weight. When magnesium hydroxide is used as a flame retardant and N, N'-m-phenylenedimaleimide is used as a flame retardant aid, the amount of N, N'-m-phenylenedimaleimide added is 100 parts by weight of the polyolefin resin. The range is preferably 1 part by weight or more and 5 parts by weight or less based on parts by weight.

In addition to the above-mentioned compounding agents, UV absorbers, antioxidants, copper damage inhibitors, pigments, dyes and other coloring agents, a small amount of inorganic fine powder such as talc, etc. Additives can be included, but those that do not contain halogen and especially lead (Pb) are selected. Further, it is preferable that harmful heavy metals such as cadmium (Cd) are not contained as much as possible, and it is preferable that the content of harmful heavy metals in the non-halogen flame-retardant resin composition of the present invention is suppressed to less than 0.1% by weight.

According to the non-halogen flame-retardant resin composition of the present invention, a resin composition having the same self-extinguishing flame retardancy as PVC can be obtained. This non-halogen flame-retardant resin composition hardly burns in a fire and emits a small amount of smoke. Also, because it does not contain halogen, it does not generate toxic gases such as dioxin and halogen gas during combustion, so it can be incinerated.
No toxic gas is emitted in case of fire. Further, since the specific gravity is smaller than that of PVC, it can be easily separated from PVC by specific gravity separation using water as a specific gravity liquid. Therefore, it is possible to recycle by separating and collecting, and it is possible to recover heat as fuel or reuse as material. Furthermore, there is no elution of lead, and landfill disposal is possible.

Since the non-halogen flame-retardant resin composition of the present invention passes the 60 ° inclined combustion test defined in JIS C3005, for example, insulated wires, wires for electronic equipment, wires for automobiles, and wires for equipment Insulation and sheathing materials for various electric wires and cables such as electric wires, power cords, insulated electric wires for outdoor distribution, electric power cables, control cables, communication cables, instrumentation cables, signal cables, transfer cables, and ship cables It is suitable as an adhesive, tapes, and inclusions, and provides a flame-retardant electric wire / cable. In addition to these, accessories for electric wires and cables such as cases, plugs, and tapes, electrical products such as conduits, wiring ducts, and bus ducts; agricultural sheets; water hoses; It is also suitable for interior materials and floor materials.

The flame-retardant electric wire / cable of the present invention uses the above-described 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. Further, depending on the use of the electric wire or cable, a suitable 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.

Thus, according to the present invention, a flame-retardant electric wire or cable having an insulator and / or a sheath or an inclusion having excellent self-extinguishing flame retardancy can be obtained. The flame-retardant wires and cables obtained in this way are JIS C30
It passes the 60 ° tilt combustion test established in 2005, is hard to burn in a fire and emits a small amount of 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. Such flame-retardant wires and cables of the present invention include, for example, insulated wires, wires for wiring electronic devices, wires for vehicles, wires for devices, power cords, insulated wires for outdoor power distribution, power cables, control cables, and communication cables. Cable, instrumentation cable, signal cable, transfer cable, ship cable, and the like.

[0018]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples. As examples and comparative examples of the present invention,
A mixture of a polyolefin-based resin, a metal hydroxide, and a flame retardant auxiliary in the proportions shown in Table 1 below was formed into a sheet having a thickness of 3.0 mm to obtain a sample. As the polyolefin resin, an ethylene-ethyl acrylate copolymer (EEA) and an olefin copolymer are used.
As the metal hydroxide, magnesium hydroxide (Mg (O
H) ₂ ) was used, and red phosphorus, carbon black, and N, N'-m-phenylenedimaleimide (HVA-2: manufactured by du pont) were used as flame retardants. The specific gravity and flame retardancy of the obtained sample were examined. For evaluation of flame retardancy, JIS
Oxygen index (O) according to the test method established in K7201
I) and pass / fail in the 60 ° tilt combustion test established in JIS C3005 were used. The results are shown in Table 1 below.
Shown in

[0019]

[Table 1]

[0020]

As described above, according to the present invention, since the specific gravity is 1.14 or less, it can be separated and recovered from PVC by specific gravity separation, and has the same flame retardancy as PVC. A non-halogen flame-retardant resin composition which can be used as a coating material for flame-retardant electric wires and cables and similar products and which does not contain halogen and which can be incinerated can be obtained. Furthermore, since it hardly contains heavy metals, landfill disposal is possible, and the burden on the environment during treatment is small. Further, the electric wire / cable of the present invention uses such a non-halogen flame-retardant resin composition for a sheath material, an insulator material, a sheath material and an insulator material, or an inclusion material on a stranded core wire. Has excellent flame retardancy.
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.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a sedimentation trajectory of plastic in a water flow.

[Explanation of symbols]

1: olefin plastic, 2: polyvinyl chloride,
3: Styrene-based plastic

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 23/00 C08L 23/00 H01B 7/34 H01B 7/34 B (56) References JP-A-7-276366 (JP, A) JP-A-4-110340 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01B 3/44 C08K 3/00-3 / 32 C08L 23/00-23/30 H01B 7/34 B29B 17/00

Claims (3)

(57) [Claims] (1) 100 parts by weight of a polyolefin resin
And 20 to less than 50 parts by weight of a metal hydroxide, and 2 to less than 10 parts by weight of a flame retardant auxiliary, having a specific gravity of 1.14 or less and an oxygen index of 24 or more and 34 or less. A non-halogen flame-retardant resin composition characterized by passing a 60 ° inclined combustion test defined in JIS C3005 when used as a coating material for electric wires, cables or similar products. 2. For the polyolefin resin 100 parts by weight, metal hydroxide 20 parts by weight or more than 50 parts by weight, Akari
Emissions less than 0.5 part by weight to 2.5 parts by weight, and carbon
Black is added in an amount of 1 part by weight or more and less than 6 parts by weight.
Weight is 1.14 or less, oxygen index is 24 or more and 34 or less,
Used as a coating material for wires, cables or similar products
Sometimes JIS C3005 enacted 60 ° tilt combustion
A non-halogen flame-retardant resin composition which passes a test . 3. A flame-retardant electric wire or cable, wherein the resin composition according to claim 1 or 2 is used as a covering material for an electric wire or cable or an inclusion material on a stranded core wire.