JPH10324783A - Flame retardant insulating cover composition - Google Patents

Abstract

(57) [Summary] [Problem] A flame-retardant insulating cover (insulator cover, high-voltage wire protection cover, etc.) that improves the flow characteristics during molding and is excellent in flame retardancy, mechanical properties, electrical properties, and surface properties. And b) providing a composition suitable as a molding material. The melt index is 0.1 to 10 g / 10.
, 100 parts by weight of an ethylene-α-olefin copolymer produced with a single-site catalyst having a density of 0.870 to 0.930 g / cm ³ , a metal hydroxide [Mg (OH) ₂ etc.]
10 to 50 parts by weight, 10 to 50 parts by weight of an organic halogen-based flame retardant [1,2-bis (pentabromophenyl) ethane or the like], 1 to 20 parts by weight of an antimony-based flame retardant (Sb ₂ O ₃ or the like), phosphorus-based Plasticizer (such as trioctyl phosphate)
A flame-retardant insulating cover composition comprising 5 to 5 parts by weight and 0.01 to 1 part by weight of a fluororesin (such as polytetrafluoroethylene). The above composition to which a weathering agent or a lubricant is added.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a flame-retardant insulating cover, and more particularly to a composition comprising an ethylene-.alpha.-olefin copolymer produced by a single-site catalyst as a main component and having excellent flame retardancy. It has excellent mechanical properties and insulation properties, and has good molding workability during production. It is suitable for use as a molding material for insulation covers such as insulator covers and high-voltage wire protection covers. It is about things.

[0002]

2. Description of the Related Art Conventionally, insulating covers, such as insulator covers for power transmission and distribution lines and high-voltage wire protective covers, require insulation, weather resistance, arc resistance, tracking resistance, impact resistance, low-temperature characteristics, mechanical strength, and the like. Therefore, polyethylene resins having these various properties have been used. However, since various insulating covers made of polyethylene resin are flammable, there are problems such as continued burning due to electric sparks and fires from other places, and the drip of sparks, etc. Has been requested. In particular, since the above-mentioned insulating cover is mounted on a pole for the purpose of protecting the live parts,
Because it is susceptible to lightning strikes and earth leakage, and once ignited, it may affect the suspension of distribution lines,
Various flame retardants such as metal hydroxide or organic halogen flame retardants have been added to polyethylene resins to achieve flame retardancy.

When a metal hydroxide such as aluminum hydroxide or magnesium hydroxide is used as a flame retardant, in order to obtain a predetermined flame retardancy, a large amount of a metal hydroxide is added to a polyethylene-based resin, for example, with the resin. It is necessary to mix the same amount or more. Therefore, there have been problems such as a decrease in mechanical strength of the insulating cover as a molded article from such a composition and a tendency of the surface to be damaged. On the other hand, when an organic halogen-based flame retardant is used, it is not necessary to mix as much as a metal hydroxide, but it is still an order of magnitude greater than the amount of an additive in an ordinary resin composition. Must be mixed. In the case of an insulating cover usually manufactured by injection molding, the raw resin composition must have good fluidity in a nozzle, a spool, a runner, a gate, and a cavity, but a polyethylene resin composition containing an organic halogen-based flame retardant. The product has much poorer fluidity because it has more additives than the ordinary resin composition, so it cannot be molded in a fast injection molding cycle, and the productivity is poor.
There have been problems such as roughening of the surface of the molded article, impairing the appearance, and deteriorating the electrical and mechanical properties.

[0004]

SUMMARY OF THE INVENTION The present invention overcomes the above-mentioned drawbacks of the conventional flame-retardant insulating cover composition. More specifically, the present invention improves the fluidity during molding and improves the electrical An object of the present invention is to provide a composition for a flame-retardant insulating cover which has improved properties, mechanical properties, surface properties, and flame-retardant properties and has not been proposed before.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, an ethylene-α-olefin copolymer produced using a single-site catalyst has excellent mechanical strength, Combining an organic halogen-based flame retardant with an antimony-based flame retardant significantly improves the flame-retardant effect, the fluororesin exhibits the effect of preventing the drooling phenomenon, and the metal hydroxide improves the tracking resistance and flame retardancy. ,
Furthermore, they found that a phosphorus-based plasticizer was effective in improving flow characteristics and flame retardancy during injection molding, and that when the above components were combined in a specific mixing ratio, all of the above problems could be solved. The present invention has been completed through experiments and further studies.

That is, the present invention provides a melt index of 0.1 to 10 g / 10 minutes and a density of 0.870 to 0.930.
g / cm ³ , 100 parts by weight of an ethylene-α-olefin copolymer produced using a single-site catalyst, 10 to 50 parts by weight of a metal hydroxide, 10 to 50 parts by weight of an organic halogen-based flame retardant, The present invention relates to a composition for a flame-retardant insulating cover, comprising 1 to 20 parts by weight of an antimony-based flame retardant, 0.5 to 5 parts by weight of a phosphorus-based plasticizer, and 0.01 to 1 part by weight of a fluororesin. The present invention also relates to a composition further comprising one or both of a weathering agent and a lubricant in the composition for a flame-retardant insulating cover of the present invention.

[0007] The ethylene-α-olefin copolymer produced using the single-site catalyst used in the present invention can be treated with ethylene and α-olefin, for example, a carbon atom having a single-site catalyst described in detail below. It is a copolymer with 3 to 12 α-olefins. Specific examples of the α-olefin include propylene, butene-1,
Hexene-1,4-methylpentene-1, octene-
1, decene-1 and dodecene-1.

The ethylene-α-olefin copolymer used in the present invention has the following physical properties: a melt index of 0.1 to 10 g / 10 minutes, and a density of 0.870 to 0.1.
It has 930 g / cm ³ . Here, the melt index is measured in accordance with JIS K7210.
If it exceeds g / 10 minutes, the mechanical properties will be poor, which is not desirable. The density is measured in accordance with JIS K7112. If it is less than 0.870 g / cm ³ , heat resistance and oil resistance are inferior. If it exceeds 0.930 g / cm ³ , flexibility, elongation, workability, Properties, mold release properties, etc., and the flame retardant cannot be uniformly dispersed and held in the resin component,
Not desirable.

In the present invention, the single-site catalyst used in the production of the ethylene-α-olefin copolymer has the same active site (single-site) and has a high polymerization activity with respect to ethylene. It is. The ethylene-α-olefin copolymer produced with this catalyst has a narrower composition distribution and molecular weight distribution than those produced with conventional Ziegler-based catalysts or Phillips-based catalysts, and therefore has excellent mechanical properties. This single-site catalyst is also referred to as a metallocene catalyst or, as the inventor's name, a Kaminsky catalyst. Examples of the catalyst component include those represented by the following formulas (1) to (3).

The following formula (1): (Cp) _m MR _n R ′ _p (1) wherein Cp is an unsubstituted or substituted cyclopentadienyl group, and M is a transition of groups 4 to 10 of the periodic table. Metal
R and R 'are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms or a hydrocarboxyl group, m is 1-3, n is 0-3, and p is 0-3. Wherein m + n + p is equal to the oxidation state (valence) of M].

[0011] the following equation (2) or _{(2 '): (C 5} R' m) p R "s (C 5 R 'm) MQ 3-ps (2) R" 3 (C 5 R' m) 2 MQ ′ (2 ′) (wherein C ₅ R ′ _m is an unsubstituted or substituted cyclopentadienyl group, wherein R ′s are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. , An alkenyl group, an aryl group, an alkylaryl group, an arylalkyl group, or two carbon atoms linked together to form part of a C ₄ -C ₆ ring, wherein R ″ is one or more carbon atoms. , Germanium, silicon, phosphorus or nitrogen atoms, or combinations thereof, which contain two C ₅
R by substituting 'by substituting the above _m ring group or one C ₅ R bridging them' _m ring above contain groups that bridges to M, when p is 0 x is 1 And in other cases x is always 0 and each Q is independently of each other an alkyl, alkenyl, aryl, alkylaryl, arylalkyl or halogen atom having 1 to 20 carbon atoms, Q ′ is an alkylidene group having 1 to 20 carbon atoms, s is 0 or 1, when s is 0, m is 5, and p is 0, 1 or 2, and s is When it is 1, m is 4 and p is 1
Is a transition metal compound represented by the formula: The transition metal compounds represented by the above formulas (1), (2) and (2 ′) are disclosed in JP-A-8-134121 and JP-A-8-134121.
JP-A-509773, JP-A-8-510290, and the like. The disclosure content of the above-mentioned patent publication is incorporated herein by this reference.

The following equation (3): Wherein M is a metal atom of Groups 3 to 10 of the periodic table or a lanthanoid, Cp is an unsubstituted or substituted cyclopentadienyl group bonded to M in an η ⁵ bonding mode,
Is an atomic group containing boron or an element of group 14 of the periodic table, and optionally a sulfur atom or an oxygen atom,
The radical may have atoms other than up to 20 hydrogen atoms, or Cp and Z together form a fused ring system, and X is independently of each other an anionic ligand or up to 30 hydrogen atoms. A neutral Lewis base ligand having an atom other than an atom, n is 0, 1, 2, 3, or 4, and
Is two less than the valency of M, and Y is an anionic or non-anionic ligand that binds Z and M, including a nitrogen, phosphorus, oxygen, or sulfur atom; Up to a number of atoms other than hydrogen or, if necessary, Y and Z together form a fused ring system). The transition metal compound represented by the above formula (3) is disclosed in
No. 306121, JP-A-7-500622 and the like. The disclosure content of the above-mentioned patent publication is incorporated herein by this reference.

The above catalyst further contains an activating cocatalyst. As the cocatalyst, aluminoxane having a high or low degree of polymerization, particularly methylaluminoxane, is suitable. So-called modified aluminoxanes are also suitable for use as the cocatalyst.

For the polymerization of the ethylene-α-olefin copolymer, a method such as a solution polymerization method, a suspension polymerization method, and a gas phase polymerization method can be preferably used. Generally, the temperature during the polymerization is 0 to 250 ° C. and the pressure is high (50 MPa
a or more), medium pressure (10 to 50 MPa) or low pressure (normal pressure to 10 MPa).

The metal hydroxide used in the present invention includes aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, basic magnesium carbonate, hydrotalcite, zirconium hydroxide and hydration of tin oxide. Products, borax, kaolin, clay, zinc borate, barium borate, alumite and the like. The average particle size is desirably 0.1 to 20 μm from the viewpoint of dispersibility, mechanical properties, and flame retardancy. The metal hydroxide was subjected to a surface treatment such as coating with a fatty acid such as stearic acid, oleic acid, or palmitic acid or a metal salt thereof, paraffin, wax or a modified product thereof, an organic silane, or a compound such as an organic titanate. It is possible to use a material which has been subjected to a surface treatment for improving the flame retardancy.

The mixing amount of the metal hydroxide is 10 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer.
５０50 parts by weight. If the amount is less than 10 parts by weight, the tracking resistance and the flame retardancy deteriorate, and if it exceeds 50 parts by weight, the moldability and the mechanical properties of the molded article (insulating cover) deteriorate, which is not desirable.

Examples of the organic halogen-based flame retardant used in the present invention include the following: hexabromobenzene, decabromodiphenyl oxide, polydibromophenylene oxide, bis (tribromophenoxy) ethane, ethylenebis. Pentabromobenzene, ethylenebisdibromonorbornanedicarboximide, ethylenebistetrabromophthalimide, dibromoethyldibromocyclohexane, dibromoneopentyl glycol, tribromophenol, tribromophenol allyl ether, tetrabromobisphenol A derivative, tetrabromobisphenol S, tetradecabromo diphenoxybenzene, tris (2,
3-dibromopropyl-1) isocyanurate, 2,2
-Bis (4-hydroxy-3,5-dibromophenyl)
Propane, 2,2-bis (4-hydroxyethoxy-
3,5-dibromophenyl) propane, 1,2-bis (pentabromophenyl) ethane, pentabromophenol, pentabromotoluene, pentabromodiphenyl oxide, hexabromocyclododecane, hexabromodiphenyl ether, octabromophenol ether, octabromo Diphenyl ether, octabromodiphenyl oxide, dibromoneopentyl glycol tetracarbonate, bis (tribromophenyl) fumaramido, N-methylhexabromophenylamine, brominated epoxy resin, chlorinated paraffin, chlorinated polyolefin, chlorinated polyethylene, perchloro Cyclopentadecane and the like.

The compounding amount of the organic halogen-based flame retardant is 10 to 50 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer. If the amount is less than 10 parts by weight, the flame retardancy deteriorates. If the amount exceeds 50 parts by weight, the moldability and the mechanical properties of the molded article (insulating cover) deteriorate.
Not desirable.

The antimony flame retardants used in the present invention include antimony trioxide, antimony pentoxide,
Sodium antimonate and the like can be mentioned. The compounding amount of the antimony-based flame retardant is 1 to 20 parts by weight based on 100 parts by weight of the ethylene-α-olefin copolymer. If the amount is less than 1 part by weight, the flame retardancy deteriorates, and if it exceeds 20 parts by weight, the moldability and the mechanical properties of the molded article (insulating cover) deteriorate, which is not desirable.

The phosphorus-based plasticizer used in the present invention includes tricresyl phosphate, cresyl diphenyl phosphate, trioctyl phosphate, tributyl phosphate, triphenyl phosphate, trixylenyl phosphate, triethyl phosphate, tributoxyethyl phosphate, Phenyl monoorthoxenyl phosphate, 2-ethylhexyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl isopropyl phenyl phosphate, tris (α-dichloropropyl) phosphate, tris (β-chloroethyl) phosphate, tris (β-bromoethyl) phosphate, tris ( 2,3-dibromopropyl) phosphate, bis (2,3-dibromopropyl) 2,3-dichloropropylphosphate Over, tri-butyl phosphite,
Trioctyl phosphite, isooctyl diphenyl phosphite and the like can be mentioned.

The amount of the phosphorus-based plasticizer is 0.5 to 100 parts by weight of the ethylene-α-olefin copolymer.
-5 parts by weight. If the compounding amount is less than 0.5 part by weight, the flow characteristics and flame retardancy during molding are deteriorated, and if it exceeds 5 parts by weight, the moldability and the mechanical properties of the molded product (insulating cover) are deteriorated. , Undesirable.

The fluororesin used in the present invention includes polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene-ethylene copolymer Polychlorotrifluoroethylene, chlorotrifluoroethylene-ethylene copolymer, polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-hexafluoropropylene copolymer, tetrafluoroethylene-propylene copolymer, and the like. it can.

The mixing amount of the above fluororesin is
0.01 to 100 parts by weight of the α-olefin copolymer
１1 part by weight. If the amount is less than 0.01 part by weight, the sagging phenomenon during combustion cannot be prevented, and if it exceeds 1 part by weight, the mechanical properties of the molded article (insulating cover) deteriorate, which is not desirable.

The composition for a flame-retardant insulating cover of the present invention includes:
If necessary, it is desirable to add 0.1 to 3 parts by weight of a weathering agent to 100 parts by weight of the ethylene-α-olefin copolymer in order to impart weatherability. Examples of the weather resistance imparting agent include carbon black, an ultraviolet absorber, and a light stabilizer. The ultraviolet absorber, for example, a salicylate-based ultraviolet absorber, for example, phenyl salicylate, para-tert-butylphenyl salicylate, etc.
Benzophenone type ultraviolet absorbers, for example, 2,4-dihydroxy benzophenone, 2-hydroxy-4-methoxy benzophenone, etc., benzotriazole type ultraviolet absorbers, for example, 2- (2′-hydroxy-5′-methylphenyl) Benzotriazole, 2- (2′-hydroxy-3 ′, 5′-ditertbutylphenyl) benzotriazole and the like. Light stabilizers include, for example, bis (2,
2,6,6-tetramethyl-4-piperidyl) sebacate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl} And hindered amine light stabilizers such as (2,2,6,6-tetramethyl-4-piperidyl) imino {hexamethylene} (2,2,6,6-tetramethyl-4-piperidyl) imino}. .

The composition for a flame-retardant insulating cover of the present invention may optionally contain a lubricant with respect to 100 parts by weight of an ethylene-α-olefin copolymer in order to enhance the releasability during injection molding. 0.1 to 2 parts by weight.
As the lubricant, wax, for example, paraffin wax,
Fatty acid amides such as polyethylene wax and the like, fatty acid amides such as stearic acid amide, oleic acid amide, erucamide and the like, fatty acid esters such as citric acid diester, 2
Aliphatic alcohols such as ethylhexanoate, palmityl alcohol, stearyl alcohol, etc.
Examples include metal soaps such as calcium stearate and zinc stearate, and silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane.

The composition for a flame-retardant insulating cover of the present invention comprises:
Various additives and auxiliary materials can be blended according to the purpose of use as long as the properties of the present invention are not impaired. These various additives and auxiliary materials include stabilizers, antioxidants, antistatic agents, processability improvers, fillers, dispersants, copper damage inhibitors, neutralizing agents, foaming agents, foam inhibitors, coloring agents. And the like. Further, the flame-retardant resin composition of the present invention, depending on the intended use, ethylene-based resins other than ethylene-based resins and other polyolefin-based resins used in the present invention, as long as the properties of the present invention are not impaired. A small amount can also be blended. These resins include ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and high-pressure low-density polyethylene (LDP).
E), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear low-density ethylene-α-olefin copolymer (LLDPE) produced with a catalyst other than single-site catalyst, catalyst other than single-site catalyst And a low-density linear ethylene-α-olefin copolymer (VLDPE) and polypropylene (PP). Further, the composition for a flame-retardant insulating cover of the present invention can be cross-linked by adding a cross-linking agent or a cross-linking aid, or can be cross-linked by irradiation with ionizing radiation.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The composition for a flame-retardant insulating cover of the present invention comprises a predetermined amount of an ethylene-α-olefin copolymer, a metal hydroxide, and an organic halogen produced using a single-site catalyst. -Based flame retardants, antimony-based flame retardants, phosphorus-based plasticizers and fluororesins, if necessary, the above-mentioned weathering agents, lubricants, various additives and auxiliary materials, crosslinking agents and other resins, etc. Premix the components individually or several components in order, or compound all components at once, homogenize using common methods such as kneaders, Banbury mixers, continuous mixers or extruders. And can be manufactured by mixing and kneading.

[0028]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Using the following raw materials, the compositions shown in Table 1 were kneaded with a Banbury mixer at 180 ° C. for 10 minutes, and then granulated to obtain pellets. Using the pellets prepared in this way, a hot press molding machine was used at 160 ° C and 150 kg / c.
Various properties were evaluated under the following conditions using the sheet obtained by molding for m ² for 3 minutes. The evaluation results are also shown in Table 1.

Raw Materials (1) Ethylene-α-olefin copolymer produced using a single-site catalyst: density 0.900 g / cm
³ , an ethylene-octene-1 copolymer (manufactured by The Dow Chemical Company) having a melt index of 7 g / 10 minutes (hereinafter referred to as component A). (2) Ethylene-α-olefin copolymer produced using a multi-site catalyst (Ziegler catalyst): density 0.910 g / cm ³ , melt index 5 g / 10
-Ethylene-butene-1 copolymer (manufactured by Nippon Unicar Co., Ltd.) (hereinafter referred to as component A ′). (3) Metal hydroxide: magnesium hydroxide surface-treated with stearic acid (hereinafter referred to as component B). (4) Organic halogen-based flame retardant: 1,2-bis (pentabromophenyl) ethane (hereinafter, referred to as component C). (5) Antimony flame retardant: antimony trioxide (hereinafter, referred to as “antimony trioxide”)
Component D). (6) Phosphorus plasticizer: trioctyl phosphate (hereinafter referred to as component E). (7) Fluororesin: polytetrafluoroethylene (hereinafter referred to as component F). (8) Weather resistance imparting agent: carbon black (hereinafter referred to as component G)
Described). (9) Lubricants: oleic acid amide (hereinafter referred to as component H).

Evaluation method (1) Melt index Measured according to JIS K7210 under the conditions of a load of 2.16 kg and a measurement temperature of 190 ° C. In Table 1, it is indicated by "MI". (2) Flow ratio This value is a measure of the molecular weight distribution, and the higher the value, the better the processability. In Table 1, it is indicated by "FR". (Flow ratio) = (Flow index) ÷ (Melt index) The evaluation of the flow index was performed in accordance with JIS K7210, and the measurement conditions were a load of 21.6 kg and a measurement temperature of 1.
90 ° C. (3) Tensile strength and elongation A sheet having a thickness of 1 mm is used.
Perform according to 0. In Table 1, they are indicated by "TS" and "EL", respectively. (4) Flame retardancy test (4) -1 Oxygen index: A sheet having a thickness of 3 mm is used in accordance with JIS K7201. The results are expressed as oxygen indices, the higher the value, the better the flame retardancy. In Table 1, it is indicated by "OI". (4) -2 Fire sag: Use a sheet having a thickness of 2.5 mm according to the flammability B method of JIS K6911. In Table 1, it is indicated by "FS". (5) Volume resistivity Performed in accordance with JIS K6723. A test piece having a width and a length of 120 mm or more is punched from a sheet having a thickness of 1 mm,
Using this, a DC voltage of 500 V is applied, and the volume resistivity after charging for 1 minute is measured. The larger the value, the better the insulation. In Table 1, it is indicated by "VR". (6) Tracking resistance A sheet having a thickness of 3 mm is used.
Perform in accordance with 5. A test is performed when the leakage current is 0.5 A or more or the fuel does not burn after spraying 101 times or more. Table 1
Is indicated by “TR”.

Examples 2 to 4 and Comparative Examples 1 to 6 The same operation as in Example 1 was repeated using the compositions having the compositions shown in Table 1. Table 1 also shows the evaluation results.
Are shown together.

[0033]

[Table 1] (Footnotes) ^{* 1} Components A to H of the raw materials are as described in Example 1. ^{* 2} Items and units of the evaluation result are as follows. MI: melt index (unit: g / 10 minutes) FR: flow ratio (no unit) TS: tensile strength (unit: MPa) EL: elongation (unit:%) OI: oxygen index (no unit), next FS: FS) together with a measure of flame retardancy, FS: dripping (no unit), dr means occurrence of dripping. VR: Volume resistivity (unit × 10 ¹⁵ Ω · cm) TR: Tracking resistance, 〇 indicates pass, × indicates reject.

The following is clear from the results shown in Table 1. First, the examples of the present invention are excellent in all evaluation results. In contrast, Comparative Examples 1 to 6 are all inferior to Examples 1 to 4 in one or more evaluation items. Comparative Example 1 was a multi-site catalyst (Ziegler-based catalyst) instead of the ethylene-α-olefin copolymer (component A) produced with a single-site catalyst as the main resin component.
Using the ethylene-α-olefin copolymer (component A ′) produced in the above, but has poor mechanical strength and flame retardancy. In Comparative Example 2, the metal hydroxide (component B) was not blended, but the flame retardancy and tracking resistance were poor. In particular, it is inferior in flame retardancy and causes dripping. Comparative Example 3, in which the organic halogen-based flame retardant (component C) was not blended, was inferior in flame retardancy and caused dripping. Comparative Example 4 does not contain an antimony-based flame retardant (component D), but has poor flame retardancy,
Has caused a dripping. In Comparative Example 5, the phosphorus-based plasticizer (component E) was not blended, but the moldability and flame retardancy were poor. Comparative Example 6, in which the fluororesin (component F) was not blended, had poor flame retardancy and caused dripping.

[0035]

As described in detail above, the composition for a flame-retardant insulating cover of the present invention comprises an ethylene-α-olefin copolymer produced using a single-site catalyst as a main component, and other components. It contains a specific amount of a metal hydroxide, an organic halogen-based flame retardant, an antimony-based flame retardant, a phosphorus-based plasticizer, and a fluororesin, each of which has excellent flame retardancy and workability, that is, a high oxygen index and a high fire index. It is less likely to cause a dripping phenomenon, has improved flow characteristics during molding, and has good mechanical properties, insulation properties, tracking resistance, surface properties, and the like. Further, by adding a weather resistance imparting agent or a lubricant to the composition of the present invention, the weather resistance or the releasability at the time of molding can be further improved. Furthermore, since the composition for a flame-retardant insulating cover of the present invention has such excellent properties, it is suitable as a molding material for an insulating cover such as an insulator cover or a high-voltage electric wire protective cover.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23/16 C08L 23/16 23/18 23/18 H01B 3/44 H01B 3/44 P 17/60 17/60 G // (C08L 23/08 27:12)

Claims (3)

[Claims] 1. Melt index 0.1 to 10 g / 1
0 min, density 0.870-0.930 g / cm ³ ,
Ethylene-α produced using a single-site catalyst
-100 parts by weight of olefin copolymer, metal hydroxide 10
To 50 parts by weight, 10 to 50 parts by weight of an organic halogen-based flame retardant, 1 to 20 parts by weight of an antimony-based flame retardant, 0.5 to 5 parts by weight of a phosphorus-based plasticizer, and 0.01 to 1 part by weight of a fluororesin. A composition for a flame-retardant insulating cover, comprising: 2. The method according to claim 1, further comprising a weathering agent.
The composition for a flame-retardant insulating cover according to the above. 3. The method according to claim 1, further comprising a lubricant.
The composition for a flame-retardant insulating cover according to the above.