JP4717347B2 - Weather resistant flame retardant resin composition and electric wire - Google Patents

Description

  The present invention has no generation of harmful gases such as halogen-based gas at the time of combustion, and has a good balance of mechanical strength, heat resistance, electrical properties (withstand voltage, insulation resistance), flame retardancy and weather resistance, for example, The present invention relates to a flame retardant resin composition suitable as an insulating coating material or sheath material for lead wires of lighting equipment installed indoors and outdoors, and an electric wire provided with a coating made of the resin composition.

PVC (polyvinyl chloride) is often used as an insulator used in electric wires for lighting equipment, but when PVC is used, problems such as generation of hydrogen chloride gas and dioxin during incineration, Since there is a problem that heavy metals and plasticizers flow out at the time of landfilling, as a substitute for PVC, a technical study for blending a metal hydrate as a flame retardant into an olefin polymer has been conducted. However, in order to impart flame retardancy equivalent to that of polyvinyl chloride (PVC), a large amount of metal hydrate must be mixed in the olefin polymer, which causes a disadvantage that the weather resistance is lowered. there were. If the weather resistance is insufficient, when used as an insulation coating material or sheath material for electric wires used in lighting equipment, etc., cracks occur due to light or heat, resulting in poor insulation. It was difficult to use for etc. Therefore, conventionally, countermeasures such as imparting weather resistance by blending a light stabilizer or an ultraviolet absorber with a resin composition obtained by blending a metal hydrate with an olefin polymer have been taken. (See Patent Document 1 to Patent Document 5.)

  As a technique related to the present invention, Patent Document 6 has been filed by the applicant.

JP 2000-143883 A JP 2001-126547 A JP 2001-312925 A JP 2003-82172 A JP 2003-192846 A Japanese Patent Application No. 2002-233107

However, when the resin composition obtained by Patent Document 1 to Patent Document 5 is used as an insulating coating material or sheath material for electric wires used in lighting equipment or the like for a long period of time, the light stabilizer blended in the resin composition In addition, since the ultraviolet absorber gradually moves to the surface and volatilizes, there is a problem that the weather resistance does not last for a long time. These documents also describe the use of a light stabilizer that does not easily migrate to the surface, but in this case, the effect of preventing deterioration at the initial stage cannot be expected, and as a result, the life of the resin composition There was a problem that became short. In addition, as described above, in order to impart flame retardancy, it is essential to blend metal hydrates with olefin polymers, but blending a large amount of metal hydrates is only a decrease in weather resistance. Therefore, the mechanical strength and the insulation resistance are reduced. Therefore, it has been very difficult to obtain a resin composition having a good balance of mechanical strength, heat resistance, electrical characteristics (voltage resistance, insulation resistance), flame retardancy, and weather resistance.

  As a result of various studies to solve such problems of the prior art, the present inventors have used a combination of two types of light stabilizers and UV absorbers having different molecular weights with respect to a specific base polymer. Furthermore, it has been found that a resin composition having a good balance of mechanical strength, heat resistance, electrical properties (voltage resistance, insulation resistance), flame retardancy and weather resistance can be obtained by blending them in specific amounts. Invented.

That is, the weather-resistant flame retardant resin composition according to claim 1 of the present invention comprises 90 to 97% by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 41% and 3 to 10% by weight of an polyolefin modified with an acid. % Based on 100 % by weight of base polymer, 80 to 150 parts by weight of metal hydrate, 0.2 to 10 parts by weight of high molecular weight hindered amine light stabilizer having a molecular weight of more than 1000, and low molecular weight of 1000 or less. It is characterized by blending 0.2 to 10 parts by weight of a hindered amine light stabilizer and 0.1 to 1 part by weight of an ultraviolet absorber.
The weather-resistant flame retardant resin composition according to claim 2 is further characterized by further blending 1 to 5 parts by weight of an antioxidant .
The weather-resistant flame retardant resin composition according to claim 3 is further characterized by further blending 0.2 to 1.5 parts by weight of a hydrazine-based metal deactivator.
An electric wire according to claim 4 is provided with a coating made of the resin composition according to any one of claims 1 to 3, and the resin composition is crosslinked. It is.

  The weather resistant flame retardant resin composition according to the present invention is a combination of two types of light stabilizers and UV absorbers having different molecular weights, in which a metal hydrate is blended with a base polymer mainly composed of an ethylene-vinyl acetate copolymer. Further, by blending them in a specific amount, a resin composition having a good balance of mechanical strength, heat resistance, electrical characteristics (voltage resistance, insulation resistance), flame retardancy and weather resistance can be obtained. This composition is suitable as an insulating coating material or sheath material for lead wires of lighting equipment installed indoors or outdoors.

  Hereinafter, each component which comprises the weather-resistant flame-retardant resin composition of this invention is demonstrated.

The base polymer in the present invention is mainly composed of an ethylene-vinyl acetate copolymer, and a polyolefin modified with an acid can be appropriately blended as required to improve mechanical strength.
(A) Ethylene-vinyl acetate copolymer
The ethylene-vinyl acetate copolymer used in the present invention has a vinyl acetate content of 15 to 41% by weight, preferably 28 to 33% by weight. If the vinyl acetate content is less than 15% by weight, the desired flame retardancy and heat resistance cannot be balanced. If the vinyl acetate content exceeds 41% by weight, the workability and mechanical properties during molding are reduced, and the tackiness is increased. Will cause blocking. Moreover, regarding a melt mass flow rate (MFR), the range of 0.5-10 g / 10min is preferable, More preferably, 0.5-5g / 10min is used. When the value of the melt mass flow rate is larger than 0.5 g / 10 min, a good appearance can be obtained at the time of extrusion molding, and the mechanical properties of the weather-resistant flame retardant resin composition obtained when it is smaller than 10 g / 10 min. And a decrease in heat resistance can be prevented. In addition, ethylene-vinyl acetate copolymer may be used individually by 1 type, and may mix and use 2 or more types.

(B) Polyolefin modified with acid The acid-modified polyolefin used in the present invention is polyethylene such as low density polyethylene (LDPE), high density polyethylene (HDPE), linear polyethylene (LLDPE), or ethylene acrylic. Unsaturated carboxylic acids as acids such as acid ester copolymers (EMA), ethylene ethyl acrylate copolymers (EEA), ethylene butyl acrylate copolymers (EBA), ethylene vinyl acetate copolymers, etc. What modified | denatured by reacting an acid or its derivative (s) can be used. Examples of the unsaturated carboxylic acid include maleic acid, itaconic acid, fumaric acid and the like. Examples of unsaturated carboxylic acid derivatives include maleic acid monoester, maleic acid diester, maleic anhydride, itaconic acid monoester, itaconic acid diester, itaconic anhydride, fumaric acid monoester, fumaric acid diester, fumaric anhydride, etc. Is mentioned. Among these, a polyolefin modified with maleic anhydride is preferable, and a terpolymer of ethylene-ethyl acrylate-maleic anhydride is more preferable. When blending an acid-modified polyolefin, it is preferable that 3 wt% or more and 10 wt% or less is blended in the base polymer. If it is less than 3% by weight, the effect of improving the mechanical strength of the composition is not sufficient, and if it exceeds 10% by weight, the balance of various properties tends to be poor.

(C) Metal hydrate As metal hydrate, use magnesium hydroxide, aluminum hydroxide, calcium hydroxide, hydrotalcite, dosonite, calcium aluminate, zinc borate, borax, zinc hydroxytinate, etc. Can do. These can be used alone or in combination of two or more. Of these, magnesium hydroxide and aluminum hydroxide which release crystal water near the decomposition temperature of the polymer and have a large endothermic amount are preferable. The particle size of the metal hydrate is preferably 0.1 to 30 μm, more preferably 0.3 to 3 μm in terms of flame retardancy, kneadability, extrudability, mechanical strength and elongation. used. If the particle size of the metal hydrate is 30 μm or more, the mechanical strength tends to be lowered, and if it is 0.3 μm or less, the viscosity at the time of melting increases and the extrudability may be deteriorated.

  These metal hydrates are blended in an amount of 80 to 150 parts by weight with respect to 100 parts by weight of the base polymer. If the blending amount of the metal hydrate is less than 80 parts by weight, it is difficult to obtain the desired sufficient flame retardancy (for example, a level that passes the 60-degree tilt test specified in JIS C 3005). On the other hand, if it exceeds 150 parts by weight, the mechanical strength, insulation resistance and weather resistance of the composition will be lowered.

  These metal hydrates include, for example, higher fatty acids such as lauric acid, stearic acid and oleic acid, or higher fatty acid metal salts such as aluminum, magnesium and calcium salts, silane coupling agents and titanate surface treatment agents, etc. The surface treatment agent can be used for surface treatment. These surface treatment agents are preferably used for improving the affinity and dispersibility of the base polymer and the metal hydrate and improving the insulation resistance. Among these, a silane coupling agent can be preferably used in that it provides excellent mechanical strength to the flame retardant composition and more excellent flame retardancy than higher fatty acids and higher fatty acid salts. These surface treatment agents may be used alone or in combination of two or more. In addition, in the case of surface treatment, a metal hydrate that has been surface-treated in advance may be used, or a surface treatment agent may be blended together with an untreated or surface-treated metal hydrate to perform surface treatment. Also good.

  In the present invention, a light stabilizer is blended for the purpose of imparting weather resistance. At this time, two kinds of light stabilizers having different molecular weights (a high molecular weight hindered amine light stabilizer and a low molecular weight hindered amine light stabilizer) are used. Agent). When each is used alone, sufficient weather resistance cannot be imparted. This is due to the following reasons. That is, when the insulation coating material or sheath material of the electric wire is deteriorated by sunlight or ultraviolet rays emitted from lighting equipment, the process proceeds from the surface. For this reason, it can be said that a light stabilizer that is easily transferred from the inside to the surface is effective. Low molecular weight hindered amine light stabilizers are small in size and easy to migrate, so they can effectively prevent deterioration at the initial stage, but these gradually bleed out and dissipate to the outside. Therefore, the effect of the light stabilizer is impaired and the weather resistance is not sustained for a long time. On the other hand, high-molecular-weight hindered amine light stabilizers have a slow migration rate, so the deterioration prevention effect due to migration from the inside against surface degradation cannot be expected in the short term, but it has the property of being difficult to dissipate. Therefore, the effect of preventing deterioration is sustained and the weather resistance is maintained for a long time. Therefore, by blending each of these two types of hindered amine light stabilizers in a certain amount or more, the low molecular weight light stabilizer in the initial stage, and the high molecular weight light stabilizer in the long term each exerts an effect of preventing deterioration. Long-term weather resistance can be imparted with a small amount.

(D) High molecular weight hindered amine light stabilizer The high molecular weight hindered amine light stabilizer has a molecular weight of more than 1000, preferably about 1200 to 5000. For example, poly [6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino] and dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine heavy succinate Examples include condensates. More specifically, commercially available products such as Kimasorb 944LD and Tinuvin 622LD can be used.

  These high molecular weight hindered amine light stabilizers are blended in an amount of 0.2 to 10 parts by weight with respect to 100 parts by weight of the base polymer. If the blending amount of the high molecular weight hindered amine light stabilizer is less than 0.2 parts by weight, the desired sufficient weather resistance cannot be obtained, and if it exceeds 10 parts by weight, an effect of improving weather resistance by increasing the amount is expected. Not only is it impossible, but the mechanical strength is lowered due to the problem of dispersibility, and further blooming occurs.

(E) Low molecular weight hindered amine light stabilizer
The low molecular weight hindered amine light stabilizer has a molecular weight of 1000 or less, preferably 600 or more and 900 or less. This is because when the molecular weight is 600 or less, the transfer rate is too high, and when the molecular weight is 900 or more, the transfer rate is too slow and the effect at the initial stage is weak. Examples of the low molecular hindered amine light stabilizer include tris (2,2,6,6-tetramethyl-4-piperidyl) benzene-1,3,5-tricarboxylate, tris (2,2,6,6). -Tetramethyl-4-piperidyl) -2-acetoxypropane-1,2,3-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -2-hydroxypropane-1,2 , 3-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) triazine-2,4,6-tricarboxylate, tris (2,2,6,6-tetramethyl-4 -Piperidyl) butane-1,2,3-tricarboxylate, tetraxy (2,2,6,6-tetramethyl-4-piperidyl) propane-1,1,2,3-tetracar Xylates, tetraxy (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetraxy (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate -Pentamethyl-4-piperidyl) and the like. More specifically, commercially available products such as ADK STAB LA-57, ADK STAB LA52, and Tinuvin 144 can be used.

  These low molecular weight hindered amine light stabilizers are blended in an amount of 0.2 to 10 parts by weight with respect to 100 parts by weight of the base polymer. If the blending amount of the low molecular weight hindered amine light stabilizer is less than 0.2 parts by weight, the desired sufficient weather resistance cannot be obtained, and if it exceeds 10 parts by weight, an effect of improving weather resistance by increasing the amount is expected. Not only is it impossible, but the mechanical strength is lowered due to the problem of dispersibility, and further blooming occurs.

(F) Ultraviolet absorber Examples of the ultraviolet absorber include 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) benzotriazole and 2- (3,5-di-t-amyl). 2-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy-5′-methyl-phenyl) benzotriazole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2- (2 '-Hydroxy-3', 5'-di-t-amylphenyl) benzotriazole, 2- [2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydro- Phthalimidomethyl) -5′-methylphenyl] benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] 2- [2-hydroxy -3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (2-hydroxy-4-octyloxyphenyl) -2H-benzotriazole, 2- (2H-benzotriazole-2 -Yl) -4-methyl-6- (3,4,5,6-tetrahydrophthalimidylmethyl) phenol and other benzotriazoles, 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2, 2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone 4-dodecyloxy-2-hydroxybenzophenone, 3,5-di-t-butyl- Benzophenone series such as 4-hydroxybenzoyl acid, n-hexadecyl ester, 1,4-bis (4-benzoyl-3-hydroxyphenoxy) butane, 1,6-bis (4-benzoyl-3-hydroxyphenoxy) hexane, Examples include cyanoacrylates represented by ethyl-2-cyano-3,3-diphenylacrylate. More specifically, those commercially available under trade names such as Tinuvin 320, Tinuvin 328, Tinuvin 234, Adeka Stub LA31, SEESORB102, SEESORB103, and SEESORB501 can be used.

  These ultraviolet absorbers are blended in an amount of 0.1 to 1 part by weight with respect to 100 parts by weight of the base polymer. If the blending amount of the UV absorber is less than 0.1 parts by weight, the desired sufficient weather resistance cannot be obtained, and if it exceeds 1 part by weight, the composition is colored yellow due to the hue of the UV absorber itself. In addition, the mechanical strength and heat resistance are lowered, and further blooming occurs.

(G) Hydrazine-based metal deactivator In the present invention, in addition to the above components, a hydrazine-based metal deactivator may be further blended. By blending a hydrazine-based metal deactivator, copper damage can be prevented while maintaining the weather resistance of the resulting resin composition. Examples of the hydrazine-based metal deactivator include decamethylene dicarboxylic acid disalicyloyl hydrazide. These metal deactivators are preferably blended in an amount of 0.2 to 1.5 parts by weight based on 100 parts by weight of the base polymer. When the compounding amount of the metal deactivator is less than 0.2 parts by weight, the effect of preventing copper damage is not sufficient, and the effect of improving heat resistance cannot be obtained. On the other hand, when the amount exceeds 1.5 parts by weight, the weather resistance is lowered and the cost is further increased.

  In the present invention, in addition to the above components, various additives that are conventionally used in electric wires and cables may be blended within a range that does not impair the object of the present invention. Examples of such additives include antioxidants, flame retardant aids, crosslinking agents, crosslinking aids, lubricants, softeners, dispersants, colorants and the like.

  Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, etc. Among them, phenolic antioxidants are preferable, and hindered phenolic antioxidants are particularly preferable. If it exists, even if it receives light and heat for a long time, a weather resistance and heat resistance can be improved, without coloring a resin composition. Examples of the hindered phenol antioxidant include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propinate], octadecyl-3- (3,5-t- Butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis [1 , 1-Di-methyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] Undecane etc. can be used.

  These antioxidants are preferably blended in an amount of 1 to 5 parts by weight with respect to 100 parts by weight of the base polymer. If the blending amount of the antioxidant is less than 1 part by weight, the effect of improving the heat resistance and weather resistance is not sufficient, and if it exceeds 5 parts by weight, the mechanical strength may be lowered. There is also a risk that the weather resistance will be lowered.

  The resin composition of the present invention is obtained by kneading the above-described constituent materials appropriately with a known kneader such as an internal mixer, a uniaxial kneader, or a biaxial kneader. be able to.

  The resin composition of the present invention thus obtained is extrusion coated on the circumference of the conductor by a known method, and then subjected to appropriate crosslinking to improve the heat resistance of the composition. The electric wire according to the aspect can be obtained. Under the present circumstances, when the composition of this invention is applied to the electric wire etc. whose coating thickness is 0.3 mm or more, the outstanding characteristic which the composition of this invention has especially expresses notably. When the thickness of the coating is less than 0.3 mm, the amount of the light stabilizer present inside the insulator is insufficient, which may cause a problem in weather resistance.

  The crosslinking method is not particularly limited. For example, 1,3-bis (t-butylperoxyisopropyl) benzene, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, dicumyl peroxide, etc. Chemical crosslinking method using organic peroxide as a crosslinking agent, irradiation crosslinking method using ionizing radiation such as X-ray, γ-ray, electron beam, proton beam, deuteron beam, α-ray, β-ray, etc. It is done.

  Examples of the present invention will be described below together with comparative examples. The details of each compounding material used in this example are as shown in Table 4.

  The compounding materials shown in Table 4 were sufficiently kneaded with a twin-screw kneader, and the resulting composition was pelletized and then supplied to a 25 mmφ extruder with L / D = 24. Under a temperature condition of 0 ° C., extrusion coating was performed with a thickness of 0.8 mm on a conductor circumference made of a tin-plated annealed copper wire of 0.8φ. Thereafter, an electron beam was irradiated under the conditions of an acceleration voltage of 650 kV and an irradiation dose of 100 kGy to produce a bridged electric wire having a finished outer diameter of 2.4 mmφ.

  Here, with a total of 23 types of cross-linked electric wires thus obtained as samples, mechanical strength (tensile strength, elongation), heat resistance, flame retardancy, electrical characteristics (voltage resistance, insulation resistance) and weather resistance Each was evaluated. In addition, the presence / absence of blooming and blocking was also confirmed. The results are shown in Tables 1 and 2 together with the amount of each compounding material.

The evaluation method is as follows.
(Mechanical strength)
Tensile strength and elongation were measured according to JIS C 3005 (2000). Each required characteristic is cited from the required characteristic of an insulator in the Electrical Appliance and Material Safety Law, and the tensile strength is 10 MPa or more and the elongation is 200% or more.
(Heat-resistant)
The sample was left for 96 hours in a thermostat kept at 120 ° C. and then taken out, and the tensile strength residual ratio and the residual elongation ratio were measured in accordance with JIS C 3005 (2000). Each required characteristic was quoted from the required insulator characteristics of the Electrical Appliance and Material Safety Law, and the residual tensile strength rate was 80% or more and the residual elongation rate was 80% or more.
(Electrical characteristics)
The withstand voltage was measured by conducting an underwater withstand voltage test in accordance with JIS C 3005 (2000). The test criteria are quoted from the required electrical properties of the Electrical Appliance and Material Safety Law. Passed (○) when the insulation breakdown did not occur after holding for 1 minute at AC 1.5 kV, and rejected when the breakdown occurred. (X). Moreover, the measurement of the insulation resistance performed the insulation resistance test in 20 degreeC water based on JISC3005 (2000). The test criterion was quoted from the required electrical properties of the Electrical Appliance and Material Safety Law, and was set to 50 MΩ · km or more.
(Flame retardance)
In accordance with JIS C 3005 (2000), a 60 degree flame retardancy test was performed. The judgment criteria of the test were determined to be acceptable (O) for those that self-extinguished within 60 seconds, and unacceptable (x) for those that did not extinguish.
(Weatherability)
A sample was set at a position 240 mm away from a 400 W transparent high-pressure mercury lamp light source located in the center of the rotary gear oven, left at 120 ° C. for 1500 hours, taken out, and measured for elongation. With respect to the required characteristics, those having 50% or more were judged as acceptable (◯), and those with less than that were regarded as unacceptable (x). Among the passes, those having an elongation of 100% or more were marked as excellent (A).
(Blooming)
The sample was sealed in an airtight bag and allowed to stand at an atmospheric temperature of 30 ° C. for 30 days, and then it was visually confirmed whether blooming had occurred on the sample surface. Those in which blooming was not confirmed by visual inspection were accepted (◯), and those in which blooming was confirmed by visual observation were rejected (×).
(blocking)
When the electric wire was bundled in a length of 500 m, the case where blocking did not occur was judged as acceptable (O), and the case where blocking was caused was regarded as unacceptable (X).

Examples 1 to 4 and Comparative Examples 1 and 2
It was confirmed that Examples 1-4 in which the vinyl acetate content of the ethylene-vinyl acetate copolymer is within the scope of the present invention satisfy various characteristics. Among them, Examples 2 and 3 are in the range of 28 to 33% of vinyl acetate content, which is a preferred range of the present invention. Compared with Example 1, the mechanical strength (elongation) and weather resistance are excellent. It was confirmed that the resin composition was excellent in mechanical strength (tensile strength, elongation) and insulation resistance, and was the most balanced resin composition. On the other hand, in Comparative Example 1, since the vinyl acetate content of the ethylene-vinyl acetate copolymer is less than 5% by weight and 15% by weight which is the lower limit of the present invention, the mechanical strength (elongation) and flame retardancy are reduced. It was confirmed that the weather resistance was rejected. In Comparative Example 2, since the vinyl acetate content of the ethylene-vinyl acetate copolymer exceeds 45 parts by weight and the upper limit of 41% by weight of the present invention, the mechanical strength (tensile strength) fails. It was confirmed that blocking occurred.

Examples 6 and 7 and Comparative Examples 11 and 12
It was confirmed that Examples 6 and 7 in which the addition amount of the acid-modified polyolefin is within the range of 3 to 10% by weight, which is the preferred range of the present invention, satisfy various characteristics. Since Comparative Example 11 did not contain an acid-modified polyolefin, the mechanical strength (tensile strength) was slightly inferior to Examples 6 and 7, although there was no problem in practical use. . Further, in Comparative Example 12 , since the blending amount of the acid-modified polyolefin exceeds 15% by weight and 10% by weight which is the preferred range of the present invention, there is no problem in practical use. Compared with 6 and 7, mechanical strength (elongation) and weather resistance were slightly inferior.

Examples 9 and 10 and Comparative Examples 3 and 4
It was confirmed that Examples 9 and 10 in which the compounding amount of the metal hydrate was within the scope of the present invention satisfied various characteristics. On the other hand, since the compounding quantity of the metal hydrate was less than 60 weight part and 80 weight part which is the lower limit of this invention in the comparative example 3, it was confirmed that a flame retardance becomes disqualified. Moreover, since the compounding quantity of the metal hydrate exceeds 150 weight part which is the upper limit of the present invention in Comparative Example 4, mechanical strength (elongation) and insulation resistance are rejected. Was confirmed.

Examples 11 and 12 and Comparative Examples 5 and 6
It was confirmed that Examples 11 and 12 in which the blending amount of the high molecular weight hindered amine light stabilizer was within the scope of the present invention satisfied various characteristics. On the other hand, since the comparative example 5 did not mix | blend the high molecular weight hindered amine type light stabilizer, it was confirmed that a weather resistance is disqualified. In Comparative Example 6, since the blending amount of the high molecular weight hindered amine light stabilizer exceeds 20 parts by weight and 10 parts by weight which is the upper limit of the present invention, the mechanical strength (tensile strength, elongation) is rejected. It was confirmed that blooming occurred.

Example 13 and Comparative Examples 7 and 8
It was confirmed that Example 13 in which the blending amount of the low molecular weight hindered amine light stabilizer is within the scope of the present invention satisfies the various characteristics. On the other hand, since the comparative example 7 did not mix | blend the low molecular weight hindered amine light stabilizer, it was confirmed that a weather resistance becomes disqualified. In Comparative Example 8, the blending amount of the low molecular weight hindered amine light stabilizer exceeds 20 parts by weight and 10 parts by weight, which is the upper limit of the present invention. Has also been confirmed.

Example 14 and Comparative Examples 9, 10
It was confirmed that Example 14 in which the blending amount of the ultraviolet absorber was within the scope of the present invention satisfied various properties. On the other hand, since the comparative example 9 did not mix | blend an ultraviolet absorber, it was confirmed that a weather resistance is disqualified. Further, in Comparative Example 10, the blending amount of the ultraviolet absorber exceeds 5 parts by weight and 1 part by weight which is the upper limit of the present invention, so that the mechanical strength (elongation) and the heat resistance (elongation residual ratio) are unsatisfactory. It was confirmed that blooming was occurring.

Examples 15-18
It was confirmed that Examples 15 and 16 in which the blending amount of the antioxidant was within the preferable range of the present invention satisfied various characteristics. On the other hand, in Example 17 , the blending amount of the antioxidant is 0.2 parts by weight, which is less than the preferred range of the present invention. Therefore, although various characteristics are satisfied, heat resistance (elongation residual ratio), weather resistance As for the property, only a value slightly exceeding the required characteristics was obtained. In Example 18, the amount of the antioxidant was 10 parts by weight, which exceeded the preferred range of the present invention, so that various characteristics were satisfied, but the weather resistance was slightly higher than the required characteristics. Only the value was obtained.

  Next, as a compounding material, a total of seven types of cross-linked electric wires obtained by adding a metal deactivator were used as samples, mechanical strength (tensile strength, elongation), heat resistance, flame resistance, electrical characteristics (voltage resistance, In addition to insulation resistance and weather resistance, copper damage resistance was evaluated. The results are shown in Table 3.

The copper damage resistance evaluation method is as follows.
(Copper damage resistance)
With the copper powder coated on the surface of the tubular sample from which the conductor was taken out, it was left in a constant temperature bath at 180 ° C. for 168 hours and then taken out to measure elongation. The test criteria were determined to be acceptable (◯) when the elongation was 100% or more, and unacceptable (X) when the elongation was 100% or more.

Examples 2, 19, 20 and Reference Examples 1-4
In Examples 19 and 20 in which a hydrazine-based metal deactivator was blended within the preferred range of the present invention, it was confirmed that various properties were satisfied and that copper damage resistance was increased as compared with Example 2. It was done. On the other hand, in Reference Example 1 , since the blending amount of the hydrazine-based metal deactivator exceeds 5 parts by weight and 1.5 parts by weight which is the upper limit of the present invention, the weather resistance is rejected. Was confirmed. Further, in Reference Examples 2 to 4 , since a metal deactivator other than hydrazine was used, it was confirmed that the weather resistance was rejected and the copper damage resistance was insufficient.

  As described above in detail, according to the present invention, two types of light stabilizers having different molecular weights are added to a flame retardant resin composition in which a metal hydrate is blended with an ethylene vinyl acetate copolymer having a specific vinyl acetate content. In combination with a UV absorber and a specific amount thereof, a resin composition having a good balance of mechanical strength, heat resistance, electrical properties, flame retardancy and weather resistance could be obtained. Therefore, this composition is suitable as an insulating coating material or sheath material for lead wires of lighting equipment installed indoors or outdoors. Further, the usage is not limited to these, and for example, it can be used as an insulating coating material for a cord-shaped heater, a constituent material for a tube, and the like.

Claims (4)

Metal hydrates 80-150 with respect to 100 parts by weight of base polymer comprising 90-97% by weight of ethylene-vinyl acetate copolymer 15-41% vinyl acetate and 3-10% by weight of polyolefin modified with acid 0.2 parts by weight of a high molecular weight hindered amine light stabilizer having a molecular weight exceeding 1000, 0.2 to 10 parts by weight of a low molecular weight hindered amine light stabilizer having a molecular weight of 1000 or less, and an ultraviolet absorber 0 weather, fire-retardant resin composition characterized by blending .1～1 and weight unit. The weather resistant flame retardant resin composition according to claim 1 , further comprising 1 to 5 parts by weight of an antioxidant. The weather resistant flame retardant resin composition according to claim 1 or 2 , further comprising 0.2 to 1.5 parts by weight of a hydrazine-based metal deactivator. An electric wire comprising a coating made of the resin composition according to any one of claims 1 to 3, and the resin composition being cross-linked.