JPH0959441A - Frame-retardant ethylenic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame-retardant ethylenic resin compsn. which is excellent in flame retardance, heat resistance, and mechanical characteristics and has good low-temp. characteristics, insulating properties, and processibility by compounding an ethylenic resin, a linear ethylene-α-olefin copolymer, and a flame retardant. SOLUTION: This compsn. is prepd. by compounding 100 pts.wt. resin component comprising 60-95wt.% at least one ethylenic resin selected from among an ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and a linear ultralow-density ethylene-α-olefin copolymer and 40-5wt.% linear ethylene-α-olefin copolymer produced by using a single-site catalyst and having a melt flow rate of 0.5-50g/10min, a density of 0.86-0.91g/cm<3> . and a ratio (Mw/Mn) of wt. average mol.wt. (Mw) to number average mol.wt. (Mn) of 3.0 or lower with 5-25 pts.wt. flame retardant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant ethylene-based resin composition, and more particularly, it has excellent flame retardancy and heat resistance, more excellent mechanical properties than conventional ones, and low-temperature properties and insulation properties. It has good workability, processability and flexibility,
The present invention relates to an ethylene resin composition that can be suitably used for coating electric wires.

[0002]

2. Description of the Related Art Conventionally, flame-retardant ethylene resin compositions are
As the base material, branched and low-density polyethylene (HPLDPE), ethylene-vinyl acetate copolymer (EVA) and ethylene-ethyl acrylate copolymer (EEA) produced by a high-pressure method are used. It has been used in combination with an organic flame retardant mainly containing a halogen flame retardant or an organic phosphorus flame retardant, or in combination with an inorganic flame retardant mainly containing magnesium hydroxide, for example. However, due to the large amount of flame retardant added to the ethylene resin, the mechanical properties have not been sufficiently satisfied.

[0003]

DISCLOSURE OF THE INVENTION The present invention has improved the above-mentioned drawbacks of the flame-retardant ethylene-based resin composition, is excellent in flame retardancy and heat resistance, and is more excellent in mechanical properties than ever before.
It is also an object of the present invention to provide a flame-retardant ethylene-based resin composition that has good low-temperature characteristics, insulation properties, processability, and flexibility, and can be suitably used for coating electric wires.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventor found the following composition and completed the present invention. That is, the present invention relates to at least one ethylene selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer and a linear / ultra-low density ethylene-α-olefin copolymer. Resin (A) 60 to 95% by weight, melt flow rate 0.5 to 50 g / 10 minutes, density 0.86 to
Substantially straight chain prepared using a single site catalyst having 0.91 g / cm ³ and a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 3.0 or less. Flame-retardant ethylene, characterized by blending 5 to 250 parts by weight of a flame retardant (D) with 100 parts by weight of a resin component consisting of 40 to 5% by weight of an ethylene-α-olefin copolymer (B). A resin composition.

The present invention also provides at least one selected from the group consisting of ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers and linear / ultra-low density ethylene-α-olefin copolymers. Ethylene-based resin (A) of 50 to 93% by weight and a melt flow rate of 0.5
To 50 g / 10 min, a density 0.86~0.91g / cm ³
And weight average molecular weight (Mw) and number average molecular weight (Mn)
40% to 5% by weight of a substantially linear ethylene-α-olefin copolymer (B) produced by using a single-site catalyst having a ratio (Mw / Mn) of 3.0 or less.
And a functional group-containing compound-modified ethylene resin (C) 40-
The present invention relates to a flame-retardant ethylene-based resin composition comprising 100 parts by weight of a resin component consisting of 2% by weight and 5 to 250 parts by weight of a flame retardant (D).

The ethylene resin (A) which is the base material used in the present invention is an ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) or an ethylene-ethyl acrylate copolymer (hereinafter referred to as EEA). ) And a linear / ultra-low density ethylene-α-olefin copolymer (hereinafter,
Described as VLDPE).

EVA and EEA have a reaction temperature of 150 to
Under a condition of 350 ° C. and a reaction pressure of 100 to 300 MPa, ethylene and vinyl acetate or ethylene and ethyl acrylate are polymerized using a radical generating catalyst such as an organic peroxide. The EVA and EEA preferably have the following physical properties: Melt flow rate (measured according to JIS K7210) of 0.5 to 50
g / 10 minutes (processability is less than 0.5 g / 10 minutes, mechanical properties are relatively poor at more than 50 g / 10 minutes); • Comonomer content of vinyl acetate or ethyl acrylate is 5 -40% by weight, especially 10-35% by weight (less than 5% by weight, the workability is relatively poor, it is difficult to uniformly disperse and retain the flame retardant in the resin component, and above 40% by weight. Relatively poor mechanical properties).

VLDPE is a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms. Specific examples of the α-olefin include propylene, butene-1,
Hexene-1,4-methylpentene-1, octene-
1, decene-1 and dodecene-1. The VLDPE preferably has the following physical properties: -The one having a melt flow rate (measured according to JIS K7210) of 0.5 to 50 g / 10 minutes (0.5 g)
If it is less than / 10 minutes, the workability is relatively poor, and if it exceeds 50 g / 10 minutes, the mechanical properties are relatively poor.) ・ Density (measured according to JIS K7112) is 0.8
6 to 0.91 g / cm ³ (0.86 g / cm
Less than ³ is difficult to manufacture, and 0.91 g / c
If it exceeds m ³ , it is difficult to uniformly disperse and retain the flame retardant in the resin component).

The VLDPE is polymerized by using a catalyst which has been generally used in the past, for example, a Ziegler type catalyst, a Phillips type catalyst or a standard type catalyst. The Ziegler type catalyst is a compound such as a titanium compound or a vanadium compound. A catalyst composed of a main catalyst composed of a transition metal compound, a co-catalyst composed of an organometallic compound such as organoaluminum, and a catalyst carrier composed of an oxide such as silicon, titanium or magnesium. What is called a Phillips catalyst is a catalyst composed of a main catalyst made of chromium oxide and a catalyst carrier made of an oxide such as aluminum, and what is called a standard catalyst is a main catalyst made of molybdenum oxide and aluminum. It is a catalyst composed of a catalyst carrier composed of an oxide such as. The polymerization is carried out at a temperature of 0 to 250 ° C., and the pressure is high pressure (50 MPa or more), medium pressure (10 to 50 MPa) or low pressure (normal pressure to 10 MPa).
Done under any of. As the polymerization method, a solution polymerization method, a suspension polymerization method, a slurry polymerization method, a gas phase polymerization method, or another polymerization method can be used.

Another base material used in the present invention, ethylene-α-olefin copolymer (B)
Is a copolymer of ethylene and an α-olefin, for example, an α-olefin having 3 to 12 carbon atoms. Specific examples of the α-olefin include propylene, butene-1,
Hexene-1,4-methylpentene-1, octene-
1, decene-1 and dodecene-1. Among these, octene-1 is particularly preferable from the viewpoint of mechanical properties and processability of the flame-retardant ethylene resin composition.

The ethylene-α-olefin copolymer (B) has the following physical properties: melt flow rate 0.5 to
It has a density of 0.86 to 0.91 g / cm ³ and a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 3.0 or less. Here, the melt flow rate is measured according to JIS K7210. If it is less than 0.5 g / 10 minutes, the workability is poor, and if it exceeds 50 g / 10 minutes, the mechanical properties are poor, which is not desirable. Further, the density is measured according to JIS K7112, and if the density is less than 0.86 g / cm ³ , the production is difficult, and if it exceeds 0.91 g / cm ³ , the ethylene-α-olefin copolymer is difficult to be produced. It is not desirable because it is not possible to uniformly disperse and retain the flame retardant. The above density range of the resin component (B) is generally classified into ultra-low density.
Furthermore, the weight average molecular weight (Mw) and the number average molecular weight (M
The ratio (Mw / Mn) with respect to n) is measured by size exclusion chromatography and needs to be 3.0 or less, preferably 2.5 or less. Mw / Mn is 3.
If it exceeds 0, the mechanical properties are inferior, which is not desirable. This Mw / Mn is a value that serves as an index of the molecular weight distribution, and the smaller the value, the smaller the molecular weight distribution.

In the present invention, the single-site catalyst used in the production of the ethylene-α-olefin copolymer (B) has the same kind of active sites (single-site) and has a high polymerization activity for ethylene. Is to have. This single-site catalyst is a metallocene catalyst,
It is also called Kaminsky catalyst from the inventor's name.
The catalyst used in the present invention is a further improvement thereof, for example, a catalyst having an appropriately constrained geometrical shape.
(Constrained Geometry Catalysts), Periodic Table No. 3 ~ 1
What contains a metal coordination complex containing a group 0 or lanthanoid (lanthanum series) metal atom and an atomic group having a delocalized π (pi) bond substituted with an atomic group that induces binding preferable. A preferred catalyst complex has the formula:

Embedded image (In the formula, M is a metal atom of Group 3 to 10 of the periodic table or a lanthanoid, and Cp * is a cyclopentadienyl group or a substituted cyclopentadienyl group bonded to M in a η ⁵ bond mode, Z 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 atomic group having up to 20 atoms other than hydrogen atom, or Cp * And Z together form a fused ring system, X independently of one another is an anionic ligand or a neutral Lewis base ligand having up to 30 atoms other than hydrogen atoms and n is 0 1, 2, 3 or 4 and 2 less than the valence of M,
And Y is an anionic or non-anionic ligand that binds to Z and M, contains a nitrogen, phosphorus, oxygen or sulfur atom and has up to 20 atoms other than hydrogen. , Or optionally Y and Z together form a fused ring system).

Specific compounds of the above catalyst complex include
(Tertiary butylamide) (tetramethyl-η ⁵ -cyclopentadienyl) -1,2-ethanediyl zirconium dichloride, (tertiary butylamide) (tetramethyl-η
⁵ -cyclopentadienyl) -1,2-ethanediyl titanium dichloride, (methylamide) (tetramethyl-
η ⁵ -Cyclopentadienyl) -1,2-ethanediylzirconium dichloride, (methylamide) (tetramethyl-η ⁵ -cyclopentadienyl) -1,2-ethanediyltitanium dichloride, (ethylamide) (tetramethyl- η ⁵ -cyclopentadienyl) methylene titanium dichloride, (tertiary butylamido) dibenzyl (tetramethyl-η ⁵ -cyclopentadienyl) silane zirconium dibenzyl, (benzylamido) dimethyl (tetramethyl-η ⁵ -cyclopentadiene (Phenyl) silane titanium dichloride, (phenylphosphide) dimethyl (tetramethyl-η ⁵ -cyclopentadienyl) silane zirconium dibenzyl, (tertiary butylamido) dimethyl (tetramethyl-η ⁵ -cyclopentadienyl) silane titanium dimethyl Etc. are examples It is.

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

Polymerization of the ethylene-α-olefin copolymer (B) in the present invention is preferably carried out by a solution polymerization method, and the conditions for a usual solution polymerization method can be directly adopted. That is, the polymerization temperature is 0 to 250 ° C., and the polymerization pressure is from normal pressure to 100 MPa. If necessary, the polymerization can be carried out according to a suspension method, a slurry method, a gas phase method or another method. Although a carrier can be used, preferably the catalyst is used in a homogeneous (eg soluble) state. Of course, when the catalyst component and its cocatalyst component are added directly to the polymerization process and a suitable solvent or diluent (including concentrated monomer) is used in the polymerization process, an active catalyst system is formed in the reactor. Is preferred. However, the active catalyst may be formed in a separate step in a suitable solvent prior to its addition to the polymerization mixture, which method is also preferred. The details of the method for producing the ethylene-α-olefin copolymer (B) are described in JP-A-6-306121 and JP-A-7-500622.

The blending amount of the above resin component (B) is 40 to 5% by weight with respect to 60 to 95% by weight of the above resin component (A) (both are adjusted to 100% by weight in total). . That is, the content of the resin component (B) is 5 to 40% by weight based on 100% by weight of the total resin components including the resin component (A) and the resin component (B). This is the resin component (B)
If the compounding amount is less than 5% by weight, the mechanical properties are not sufficiently improved, while if it exceeds 40% by weight, the flame retardancy is inferior and the cost is increased, which is not preferable.

The functional group-containing compound-modified ethylene resin (C), which is another base material optionally used in the present invention, is obtained by modifying the ethylene resin with a certain functional group-containing compound. is there. Examples of the functional group-containing compound include unsaturated carboxylic acids such as fumaric acid, acrylic acid, maleic acid, itaconic acid, methacrylic acid, sorbic acid, crotonic acid or citraconic acid, and acid anhydrides such as maleic anhydride and itaconic anhydride. , Citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 4-methylcyclohexene-1,2-dicarboxylic anhydride or 4-cyclohexene-1,2-
Dicarboxylic acid anhydrides, epoxy compounds such as glycidyl acrylate, glycidyl methacrylate or allyl glycidyl ether, hydroxy compounds such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate or polyethylene glycol monoacrylate, metal salts, For example, sodium acrylate, sodium methacrylate or zinc acrylate, or a silane compound such as vinyltrichlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane or γ-.
Methacryloxypropyltrimethoxysilane etc. can be illustrated.

The ethylene resin to be modified is not particularly limited, and any ethylene resin can be used. For example, EVA, EEA, high pressure low density polyethylene (LDPE), VLDPE, linear low density resin. Ethylene
α-Olefin Copolymer (LLDPE), High Density Polyethylene (HDPE), Medium Density Polyethylene (MDPE)
And ethylene-α-olefin copolymers produced using the above single-site catalyst.

The amount of the functional group-containing compound to be added and modified to the ethylene resin is 0.05 to 1 with respect to the resin.
A range of 0% by weight is preferred. As this addition modification method, a known method such as a solution method, a suspension method or a melting method can be adopted.

When the functional group-containing compound is added to the ethylene resin by the solution method among the above methods, the ethylene resin and the functional group-containing compound are charged in a nonpolar organic solvent, and a radical initiator is further added. Add 100-1
It can be done by heating to an elevated temperature of 60 ° C. Examples of the nonpolar organic solvent used at this time include hexane, heptane, benzene, toluene, xylene, chlorobenzene, and tetrachloroethane. Further, as the radical initiator, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, 2,5-dimethyl-
Examples include organic peroxides such as 2,5-di (tertiary butylperoxy) hexyne-3 and benzoyl peroxide.

When the suspension method is used for additional denaturation,
Ethylene resin modified by introducing the ethylene resin and the functional group-containing compound into a polar solvent such as water, further adding the radical initiator, and heating to 100 ° C. or higher under high pressure. Can be obtained.

Further, in the case of addition modification by a melting method, the ethylene-based resin, the functional group-containing compound and the radical initiator are melted by using a melt-kneading machine commonly used in the field of synthetic resins, such as an extruder or a Banbury mixer. A modified ethylene resin can be obtained by kneading.

The amount of the resin component (C) blended is 50 to 93% by weight of the resin component (A) and the resin component (B).
It is 40 to 2% by weight with respect to 40 to 5% by weight (all three are adjusted to 100% by weight). That is, the content of the resin component (C) is 2 to 40% by weight in 100% by weight of the total resin component consisting of the resin component (A), the resin component (B) and the resin component (C). This is because when the amount of the resin component (C) is less than 2% by weight, the mechanical properties and heat resistance are insufficiently improved, while when it exceeds 40% by weight, the flexibility, heat aging property and processability are insufficient. Is inferior.

Flame retardant (D) used in the present invention
Are, for example, organic halogen-based flame retardants, organic phosphorus-based flame retardants, and inorganic-based flame retardants.

Examples of organic halogen-based flame retardants include hexabromobenzene, decabromodiphenyl oxide, polydibromophenylene oxide, bis (tribromophenoxy) ethane, ethylene bis pentabromobenzene, ethylene bis. Dibromonorbornane dicarboximide, ethylenebis tetrabromophthalimide, dibromoethyl dibromocyclohexane, dibromoneopentyl glycol, tribromophenol, tribromophenol allyl ether, tetrabromo bisphenol A derivative, tetrabromo bisphenol 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, pentabromophenol, pentabromo Toluene, pentabromodiphenyl oxide, hexabromocyclododecane, hexabromodiphenyl ether, octabromophenol ether, octabromodiphenyl ether, octabromodiphenyl oxide,
Dibromo neopentyl glycol tetracarbonate,
Bis (tribromophenyl) fumaramide, N-methylhexabromophenylamine, brominated epoxy resin, chlorinated paraffin, chlorinated polyolefin, chlorinated polyethylene, perchlorocyclopentadecane and the like.

Examples of the organic phosphorus flame retardant include tris (chloroethyl) phosphate, tris (monochloropropyl) phosphate, tris (dichloropropyl) phosphate, triallyl phosphate, tris (3-hydroxypropyl) phosphine oxide, tris (tribromophenyl). ) Phosphate, tetrakis (2-chloroethyl) ethylene diphosphate, glycidyl-α-methyl-β-di (butoxy) phosphinylpropionate, dibutylhydroxymethylphosphonate, di (butoxy) phosphinylpropylamide, Dimethylmethylphosphonate, ethylene bis tris (2-
Examples thereof include amine phosphates such as cyanoethyl) phosphonium bromide, ammonium polyphosphate, and ethylenediamine phosphate, and amine phosphates.

As the inorganic flame retardant, huntite, hydromagnesite, antimony trioxide, aluminum hydroxide, magnesium hydroxide, potassium hydroxide, calcium hydroxide, calcium phosphate, zircon oxide, titanium oxide, zinc oxide, magnesium oxide, Magnesium carbonate,
Calcium carbonate, barium sulfate, barium borate, barium metaborate, zinc borate, zinc metaborate, anhydrous alumina, molybdenum disulfide, clay, red phosphorus, diatomaceous earth, kaolinite, montmorillonite, hydrotalcite, talc, silica, Examples include white carbon, zeolite, asbestos, lithopone, and the like. When using these inorganic flame retardants, fatty acid such as stearic acid, oleic acid or palmitic acid or a metal salt thereof, paraffin, wax, or modified products thereof, organic silane, organic borane or organic titanate is used on the surface of the flame retardant. It is preferable to carry out a surface treatment such as coating with etc.

The above-mentioned organic halogen-based flame retardants, organic phosphorus-based flame retardants and inorganic flame-retardants may be used alone,
Needless to say, a plurality of combinations may be used.

The flame retardant (D) is blended in an amount of 5 to 250 parts by weight per 100 parts by weight of the resin component [the total amount of the components (A) and (B) and optionally the component (C)]. This is because if the amount of the flame retardant compounded is less than 5 parts by weight, the flame retardancy is insufficient, while if it exceeds 250 parts by weight, not only the moldability deteriorates, but also the mechanical properties and low temperature properties of the molded product. And deterioration of flexibility and the like.

The flame-retardant ethylene resin composition of the present invention is
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. As these various additives and auxiliary materials, stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, processability improvers, fillers, dispersants, copper damage inhibitors, neutralizing agents. , A foaming agent, an air bubble inhibitor, a coloring agent, carbon black and the like. It is also possible to crosslink by adding a crosslinking agent for crosslinking, for example, an organic peroxide, sulfur or a silane-based crosslinking agent or a crosslinking aid, or to perform crosslinking by irradiation with ionizing radiation.

The flame-retardant ethylene resin composition of the present invention is
A predetermined amount of the components (A), (B) and (D) or (A), (B), (C) and (D) may be supplemented with the above-mentioned various additives, auxiliary materials, crosslinking agents, etc. Add an appropriate amount,
Common methods, such as kneaders, Banbury mixers,
It can be produced by uniformly mixing and kneading with a continuous mixer or an extruder.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Some of the ethylene-α-olefin copolymers (B) used in the present invention are sold as Affinity (registered trademark) by The Dow Chemical Company, USA. The resin is produced using a geometrically constrained catalyst, which is a kind of single-site catalyst, and has 0.01 to 100 carbon atoms in the main chain of the ethylene-α-olefin copolymer per 1,000 carbon atoms. It contains long chain branches in a ratio of three. Since it contains this long-chain branch, it has a small Mw / Mn, that is, it has good processability despite its small molecular weight distribution. The small molecular weight distribution means that the mechanical properties are excellent. Conventionally, in an ethylene-α-olefin copolymer, a small molecular weight distribution, that is, excellent mechanical properties and good processability have not been compatible, but the resin component (B) in the present invention has mechanical properties. Even if the flame retardant (D) is contained in a large amount, it can be uniformly dispersed and retained in the ethylene-α-olefin copolymer by selecting one having excellent processability and an ultra-low density. It made it possible. Further, the EV in the present invention
Ethylene resin (A) of A, EEA or VLDPE
Makes the workability even better. Furthermore, the composition of the present invention is further improved in the above mechanical properties and processability by blending the functional group-containing compound-modified ethylene resin (C).

[0033]

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 Ethylene-vinyl acetate copolymer [melt flow rate 1.5 g / 10 minutes, comonomer content 18% by weight, NU
C-EVA copolymer (trade name), manufactured by Nippon Unicar Co., Ltd.
70 parts by weight, ethylene-α-olefin copolymer produced using a single site catalyst [density 0.900 g / c
m ³ , melt flow rate 0.8 g / 10 minutes, Mw / M
30 parts by weight of n-2.4 ethylene-octene-1 copolymer, Affinity (registered trademark), manufactured by The Dow Chemical Co., Ltd. and 120 parts by weight of magnesium hydroxide were kneaded in a Banbury mixer at 160 ° C. for 10 minutes, A sheet (thickness: 1 mm or 3 mm) is obtained by granulating into pellets and molding the pellets by a hot press molding machine at 150 ° C. at 100 kg / cm ² for 3 minutes. Using the sheet, a flame retardancy test, a tensile test and an elongation test are performed under the following conditions. The results are shown in Table 1.

Test Conditions (1) Flame Retardancy Test A sheet having a thickness of 3 mm was used, and JIS K720 was used.
It does based on 1. The results are expressed as oxygen indices, the higher the value, the better the flame retardancy. (2) Tensile test, elongation test A sheet with a thickness of 1 mm is used, and JIS K676 is used.
Perform according to 0.

Examples 2 to 8 and Comparative Examples 1 to 8 Using the compositions shown in Table 1, the same operation as in Example 1 is repeated. The respective results are summarized in Table 1.

From the results shown in Table 1, the following is clear. First, all the examples of the present invention have excellent flame retardancy and mechanical properties. On the other hand, Comparative Examples 1 to 6 lacked any of the resin components used in the present invention or were changed to other resin components, but each had a tensile strength higher than that of the corresponding Examples of the present invention. The strength is inferior. Further, although Comparative Examples 7 and 8 use the resin component used in the present invention, Comparative Example 7 is inferior in flame retardance due to too small amount of the flame retardant compounded, and Comparative Example 8 is conversely Since the amount is too large, mechanical properties and the like are inferior.

[0038]

[Table 1] (Footnote in Table 1) Note 1 Melt flow rate 1.5 g / 10 minutes, ethylene-vinyl acetate copolymer having a comonomer content of 18% by weight [NUC-EVA copolymer (trade name), manufactured by Nippon Unicar] Note 2 Melt Ethylene-ethyl acrylate copolymer having a flow rate of 1.5 g / 10 minutes and a comonomer content of 15% by weight [NUC-EEA copolymer (trade name), manufactured by Nippon Unicar] Note 3 Density 0.900 g / cm ³ , melt Flow rate 0.8 g / 10 min, Mw / Mn 3.3 ethylene-butene-1 copolymer [NACFLEX (registered trademark), manufactured by Nippon Unicar Co., Ltd.] Note 4 Density 0.900 g / cm ³ , melt flow rate 0 0.8 g / 10 min, Mw / Mn 2.4 ethylene-octene-1 copolymer [Affinity (registered trademark), The.
Dow Chemical Co.] Note 5: Density 0.920 g / cm ³ , melt flow rate 1.0 g / 10 min, Mw / Mn 3.3 ethylene-butene-1 copolymer [NUC polyethylene LL (trade name),
Made by Nippon Unicar Co., Ltd.] * 6 Modified copolymer of maleic anhydride 0.5% by weight * 3

[0039]

The flame-retardant ethylene resin composition of the present invention contains EVA, EEA or VL as the main component of the resin component.
An ethylene-α-olefin copolymer produced by using DPE and a single-site catalyst as a subcomponent is blended. Since the ethylene-α-olefin copolymer used here has a narrow molecular weight distribution, it has very excellent mechanical properties, and since it contains a certain amount of long-chain branches in the main chain, it is easy to process. It is excellent, and since the density is extremely low, which is classified into ultra-low density, it is possible to uniformly disperse and retain a large amount of flame retardant. In addition, EVA, which is the main component, has particularly improved workability. further,
By blending an ethylene resin modified with a functional group-containing compound as a subcomponent of the base material, the above various effects are further improved. Therefore, the flame-retardant ethylene-based resin composition of the present invention is excellent in various properties such as flame retardancy, heat resistance, processability, low temperature properties, insulation properties and flexibility,
The mechanical properties are remarkably improved as compared with the conventional flame-retardant ethylene resin composition. The flame-retardant ethylene-based resin composition having such excellent properties, particularly excellent heat resistance and mechanical properties, is an extremely suitable material for coating electric wires.

Claims (3)

[Claims] 1. At least one ethylene-based polymer selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, and a linear / ultra-low density ethylene-α-olefin copolymer. Resin (A) 60-9
5% by weight, melt flow rate 0.5 to 50 g / 10
Min, density 0.86 to 0.91 g / cm ³ and ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw /
Mn) 3.0 or less, 100 parts by weight of a resin component consisting of 40 to 5% by weight of a substantially linear ethylene-α-olefin copolymer (B) produced using a single-site catalyst A flame-retardant ethylene-based resin composition, characterized in that 5 to 250 parts by weight of a flame retardant (D) is blended in parts. 2. At least one ethylene-based copolymer selected from the group consisting of an ethylene-vinyl acetate copolymer, an ethylene-ethyl acrylate copolymer, and a linear / ultra-low density ethylene-α-olefin copolymer. Resin (A) 50-9
3% by weight, melt flow rate 0.5 to 50 g / 10
Min, density 0.86 to 0.91 g / cm ³ and ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw /
Mn) 3.0 or less, 40 to 5% by weight of a substantially linear ethylene-α-olefin copolymer (B) produced using a single-site catalyst, and a functional group-containing compound modified A flame-retardant ethylene resin composition comprising 100 parts by weight of a resin component consisting of 40 to 2% by weight of an ethylene resin (C) and 5 to 250 parts by weight of a flame retardant (D). 3. The α-olefin of the ethylene-α-olefin copolymer (B) is octene-1.
Alternatively, the flame-retardant ethylene-based resin composition described in 2.