JP2000178386A - Nonhalogen flame-retarded resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonhalogen flame-retarded resin composition which has a flame retardance similar to that of a polyvinyl chloride composition and does not generate a toxic gas when incinerated by compounding a polyolefin resin with magnesium hydroxide, a silicone powder, and melamine cyanurate. SOLUTION: This composition comprises 100 pts.wt. polyolefin resin, 10-250 pts.wt. surface-treated magnesium hydroxide as a flame retardant, 3-50 pts.wt. silicone powder as a flame retardant aid, and 5-30 pts.wt. melamine cyanurate also as a flame retardant aid, The composition may further contain suitable amounts of an ultraviolet absorber, an antioxidant, a crosslinker, a fine inorganic powder, etc. The composition has a content of harmful heavy metals lower than 0.1 wt.%, a volume resistivity of 1×1013 Ω.cm or higher, and an oxygen index of 24 or higher, exhibiting a flame retardance similar to that of polyvinyl chloride and generating smoke little when incinerated, An ethylene- vinyl acetate copolymer, an ethylene-propylene rubber, polypropylene, a linear low-density polyethylene, etc., are used as the polyolefin resins.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition having the same flame retardancy as a polyvinyl chloride (PVC) composition and containing no halogen and capable of being incinerated.

[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 was a problem that when products became waste, they could not 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.
There was a defect that the flame retardancy was inferior to that of For example, comparing the oxygen index (OI), which is one of the evaluation criteria for the flame retardancy of the resin composition, the OI of PVC is 23 to 40, whereas the OI of PE and PP is about 17 to 19. It turns out that it is inferior. Therefore, 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 usually added to the resin composition. However, the desired high flame retardancy cannot be obtained with metal hydrate alone, or when a large amount of metal hydrate is added to obtain the desired high flame retardancy, properties such as mechanical properties are significantly deteriorated. is there.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin composition having the same level of flame retardancy as PVC and generating no harmful gas during incineration.

[0005]

The above object can be attained by a non-halogen flame-retardant resin composition obtained by adding magnesium hydroxide, silicone powder, and melamine cyanurate to a polyolefin resin. With respect to 100 parts by weight of the polyolefin resin, the addition amount of magnesium hydroxide is 10 parts by weight or more and 250 parts by weight or less, the addition amount of silicone powder is 3 parts by weight or more and 50 parts by weight or less,
And the addition amount of melamine cyanurate is not less than 5 parts by weight 3
It is preferably 0 parts by weight or less. The polyolefin resin is ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene rubber, polypropylene, linear low-density polyethylene, ultra-low-density polyethylene, low-density polyethylene, medium-density polyethylene, and It is preferable that it is composed of one or more selected from the group consisting of high-density polyethylene. And the non-halogen flame-retardant resin composition of the present invention is an electric wire,
When used as a covering material for cables or similar products, the Electrical Appliance and Material Control Law, UL Standard, IEEE Standard 383,
And one or more of the combustion tests specified in IEC Standard 332-1.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The halogen-free flame-retardant resin composition of the present invention (herein referred to as non-halogen flame-retardant resin composition) comprises:
A preferred high flame retardancy can be achieved by adding a metal hydrate as a flame retardant to a polyolefin resin containing no halogen and using a flame retardant auxiliary in combination.

The polyolefin resin used in the present invention includes ethylene-vinyl acetate copolymer (EVA),
Ethylene-ethyl acrylate copolymer (EEA), ethylene-propylene rubber (EPR), polypropylene (PP), linear low density polyethylene (LLDPE),
Very low density polyethylene (VLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE),
And high-density polyethylene (HDPE). These resins may be used alone or in a combination of two or more. In particular, EVA has a higher flame retardancy than the other resins described above, and therefore can be used alone or in combination with other resins to achieve higher flame retardancy. preferable.

[0008] The metal hydrate used in the present invention decomposes into oxides and water vapor during combustion to exhibit flame retardancy.
Magnesium hydroxide is preferably used. When magnesium hydroxide (Mg (OH) ₂ ) is added to a polyolefin resin, magnesium hydroxide is decomposed into an oxide and water vapor during combustion, thereby lowering the temperature and generating oxygen by the generated steam. Control supply. 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, magnesium hydroxide surface-treated with a coupling agent or the like is particularly preferably used for the purpose of improving the adhesion between the resin and the surface of the metal hydrate and securing mechanical properties. In the present invention, the amount of magnesium hydroxide to be added is 10 parts by weight or more and 250 parts by weight or less, more preferably 40 parts by weight or more and 150 parts by weight or less based on 100 parts by weight of the polyolefin resin. If the added amount of magnesium hydroxide is too small, favorable flame retardancy cannot be obtained, and if it is too large, the resulting non-halogen flame-retardant resin composition will have significantly reduced mechanical properties and insulation resistance.

In the present invention, silicone powder and melamine cyanurate are used as a flame retardant auxiliary used in combination with magnesium hydroxide. The addition amount of the silicone powder is 3 parts by weight or more and 50 parts by weight or less, more preferably 5 parts by weight or more and 3 parts by weight or more with respect to 100 parts by weight of the polyolefin resin.
0 parts by weight or less. The amount of silicone powder added is 3
If the amount is less than 10 parts by weight, favorable flame retardancy cannot be obtained, and if the amount is more than 50 parts by weight, the cost of raw materials increases but the improvement in flame retardancy cannot be expected much. If the amount of melamine cyanurate is too small, the effect of addition to flame retardancy cannot be obtained, and if it is too large, the mechanical properties such as tensile strength and tensile elongation are significantly reduced. 5 to 30 parts by weight, more preferably 5 to 30 parts by weight
Not less than 20 parts by weight.

As described above, preferable high flame retardancy is achieved by adding magnesium hydroxide, silicone powder and melamine cyanurate as essential components to the above-mentioned polyolefin resin, and coating of electric wires, cables or similar products is achieved. When used as a material, the Electrical Appliance and Material Control Law, UL Standard, IEEE Standard 383, and IE
It is possible to obtain a halogen-free flame-retardant resin composition that passes at least one of the combustion tests specified in the C standard 332-1.

In addition to the above compounding agents, ultraviolet absorbers, anti-aging agents, cross-linking agents, copper damage inhibitors, pigments, dyes and other coloring agents, small amounts of inorganic fine powder such as talc, etc. Any suitable additives can be blended, but those which 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. Further, the non-halogen flame-retardant resin composition of the present invention may have a degree of foaming of less than 10%. Furthermore, when the non-halogen flame-retardant resin composition of the present invention is used as an insulating material, the volume resistivity is preferably set to 1 × 10 ¹³ (Ω · cm) or more.

Such a non-halogen flame-retardant resin composition has an oxygen index (OI) of 24 or more, has a self-extinguishing flame retardancy equivalent to that of PVC, is difficult to burn in a fire, and has a small amount of smoke. . Also, because it does not contain halogen and does not generate toxic gases such as dioxin and halogen gas during combustion,
Can be incinerated and does not emit toxic gases in the event of fire. Furthermore, there is no elution of lead, and landfill disposal is possible.

The non-halogen flame-retardant resin composition of the present invention includes, for example, insulated wires, electronic device wiring wires, automobile wires, device wires, power cords, insulated wires for outdoor distribution, power cables, control cables, Insulation materials, sheath materials, tapes, and inclusions for various cables and cables such as communication cables, instrumentation cables, signal cables, transfer cables, and ship cables, as well as wires and cables for cases, plugs, and tapes. Cable accessories (specifically, shrink tubing, rubber stress relief cones, etc.), electrical materials such as conduits, wiring ducts, and bus ducts, as well as agricultural seats, water hoses, gas pipe coverings, and building interiors It is suitable for materials and floor materials.

[0014]

EXAMPLES Hereinafter, the effects of the present invention will be clarified by showing specific examples. As examples and comparative examples of the present invention,
Various components were blended in the blending ratios (unit: parts by weight) shown in Tables 1 and 2 below, and kneaded with a kneader to obtain a resin composition.
In order to conduct a combustion test, the kneaded resin composition was coated on a 2 mm ² conductor with a thickness of 0.8 mm using an extruder to produce an electric wire. The combustion test uses this electric wire to establish a 60 ° tilt combustion test specified in the Electricity Control Law combustion test, UL standard V
W-1 vertical combustion test, IEC standard 332-
1 and a vertical tray combustion test defined in IEEE Standard 383, respectively. The results are shown in the table below. In the table, ○ indicates pass, and × indicates reject.
Further, the oxygen index (OI) according to the test method of JIS K7201, the tensile strength and the tensile elongation according to the method described in JIS K7113 were measured. The results are shown in the table. The evaluation of tensile strength was 1 kgf / mm ² or more, ○, and less than 1 kgf / mm ^2, and the evaluation of tensile elongation was 2
を for 50% or more, Δ for 200% or more and less than 250%, 20
Less than 0% was indicated as x. In addition, the tensile strength and tensile elongation were not measured for any of the four combustion tests that failed.

[0015]

[Table 1]

[0016]

[Table 2]

In the above Examples and Comparative Examples, the following resins and compounding agents were used, respectively. EVA: Melt flow rate (hereinafter referred to as MFR)
2.5, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 19% EEA: MFR = 0.5, an ethyl acrylate content of 1
4% ethylene-ethyl acrylate copolymer EPR: Mooney viscosity ML _{1 + 4} (100 ° C.) 40, ethylene content 70 mol%, propylene content 30 mol% ethylene propylene rubber PP: MFR = 4, density 0.91 g / cm ³ polypropylene LLDPE: MFR = 0.7, density 0.92 g / cm ³
Linear low density polyethylene VLDPE: Ultra low density polyethylene having MFR = 4, density 0.91 g / cm ³ Silicone powder: DC4-7081, manufactured by Dow Corning Toray Silicone Co., Ltd. Magnesium hydroxide: Stearic acid surface treated hydroxylated Magnesium melamine cyanurate: manufactured by Mitsubishi Chemical Corporation, melamine cyanurate Antioxidant deterioration inhibitor (antiaging agent): manufactured by Nippon Ciba Geigy, Irganox 1010

[0018]

As described above, according to the present invention, P
A non-halogen flame-retardant resin composition having the same flame retardancy as VC and containing no halogen can be incinerated. Further, according to the present invention, when used as a covering material for electric wires, cables or the like, the combustion test of the Electric Appliance and Material Control Law, UL standard, IEEE standard 383, and IEC standard 332-1, respectively. One or more of these tests can be passed, and thus a highly practical non-halogen flame-retardant resin composition can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/16 C08L 23/16 // (C08L 23/02 83:04) (C08K 13/02 3:22 5: 3477) (72) Inventor Takashi Edo 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Hirotaka Sawada 1-1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Jun Suzuki 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Hiroshi Matsui 1-5-1, Kiba, Koto-ku, Tokyo F-term in Fujikura Co., Ltd. 4J002 BB03W BB06W BB07W BB12W BB15W BF03W BG04W CP03X CQ01 DE076 EU197 FA08X FD13X FD136 FD137

Claims (4)

[Claims] 1. A halogen-free flame-retardant resin composition characterized by adding magnesium hydroxide, silicone powder, and melamine cyanurate to a polyolefin resin. 2. The amount of magnesium hydroxide added is at least 10 parts by weight based on 100 parts by weight of the polyolefin resin.
2. The halogen-free composition according to claim 1, wherein the amount of the silicone powder is 3 parts by weight or more and 50 parts by weight or less, and the amount of the melamine cyanurate is 5 parts by weight or more and 30 parts by weight or less. Flammable resin composition. 3. The polyolefin resin is an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-propylene rubber, a polypropylene, a linear low-density polyethylene, an ultra-low-density polyethylene, a low-density polyethylene, The non-halogen flame-retardant resin composition according to any one of claims 1 and 2, comprising one or more selected from the group consisting of medium-density polyethylene and high-density polyethylene. 4. When used as a coating material for an electric wire, a cable or the like, the electric appliance control law, UL standard,
The non-halogen flame-retardant resin composition according to any one of claims 1 to 3, wherein the resin composition passes at least one of the combustion tests specified in IEEE Standard 383 and IEC Standard 332-1. object.