JP2020158741A - Flame-retardant resin composition, electric wire and cable - Google Patents

Abstract

To provide a flame-retardant resin composition that is excellent in moldability and mechanical property, and is also excellent in heat resistance.SOLUTION: A flame-retardant resin composition, which is a flame-retardant resin composition containing a resin component and a metal hydrate, and in which, in the total amount of 100 mass% of the resin component, an ethylene-vinyl acetate copolymer and a compatibilizer containing a polyolefin-based resin modified with a polar group-containing compound and a polar group-containing ternary copolymer are contained by 90 mass% or more in total, and, for the total of 100 pts.mass of the ethylene-vinyl acetate copolymer and the compatibilizer, the metal hydrate is contained by 150 to 250 pts.mass.SELECTED DRAWING: None

Description

The present invention relates to a flame-retardant resin composition, and electric wires and cables using the same. The present invention specifically relates to a flame-retardant resin composition having excellent molding processability and mechanical properties and also having excellent heat resistance, and an electric wire and a cable using the composition.

Conventionally, a polyvinyl chloride resin composition has been used as a flame-retardant material such as an electric wire or a cable covering material. However, the polyvinyl chloride resin composition has a drawback that it produces a toxic halogen-containing gas when burned in the event of a fire or waste incineration. In order to overcome such drawbacks of polyvinyl chloride, a resin composition (non-halogen flame-retardant material) in which a metal hydrate such as magnesium hydroxide is mixed with a polyolefin resin has been proposed.

In recent years, non-halogen flame-retardant polyethylene resins for electric wires or cables are particularly required to have low smoke emission (LSZH: Low Smoke Zero Halogen). In order to achieve this LSZH, it is generally necessary to add a high amount of filler such as metal hydrate. However, if a high amount of filler is added, the fluidity during extrusion molding becomes insufficient and it becomes difficult to secure molding processability, and it becomes difficult to secure mechanical properties such as tensile breaking strength. On the other hand, if a resin having high fluidity is selected as the base raw material resin in order to suppress the decrease in fluidity, there is a problem that the heat resistance is deteriorated and the resin is easily deformed by heating.

Under such circumstances, for example, Patent Document 1 contains maleic anhydride grafted polyethylene having a melting point of more than 115 ° C. (° C) as a coupling agent (copolymerizer) for a flame-retardant thermoplastic composition. Further, a coupling agent containing an ethylene-acrylic acid ester-maleic anhydride ternary copolymer in a proportion of 33% by mass to 99.5% by mass, and a halogen-free flame-retardant thermoplastic composition containing the coupling agent. The thing is disclosed.

Further, Patent Document 2 describes a halogen-free flame-retardant thermoplastic composition having a flame-retardant filler of 50 to 70% by weight and an ethylenic property having a polar functional group of 0.1 to 45% by weight. Monomeric and ethylene copolymer, 10-25% by weight non-functional ultra-low density polyethylene (VLDPE), optionally up to 10% additive, and 0.1 to 10% by weight linear low density Characterized by being made of polyethylene (LLDPE), the density of ultra-low density polyethylene (VLDPE) is 0.85 to 0.91, the density of linear low density polyethylene is higher than 0.91 and the direct A composition in which linear low density polyethylene (LLDPE) is grafted with a maleic anhydride graft present in the main chain has been proposed.

Further, Patent Document 3 describes 30 to 50 parts by mass of a high-density polyethylene, an ethylene-acrylic acid ester-maleic anhydride ternary copolymer, and 5 to 20 parts of an ethylene-α-olefin copolymer modified with maleic anhydride. A non-halogen crosslinkable resin composition in which 120 to 200 parts by mass of metal hydroxide is mixed with 100 parts by mass of a polymer blend composed of 10 to 30 parts by mass of an ethylene-vinyl acetate copolymer. Proposed.

International Publication No. 2013/107971 Special Table 2016-531982 Special Table 2016-108391

However, the compositions described in Patent Documents 1 to 3 are not always sufficient as a material that secures fluidity and mechanical properties during molding and is also excellent in heat resistance.
Under these circumstances, there is a demand for a non-halogen flame-retardant material that solves the problems of conventional flame-retardant resin compositions for electric wires or cables, has excellent molding processability and mechanical properties, and also has excellent heat resistance. ..

In the present invention, in view of the above-mentioned problems of the prior art, a flame-retardant resin composition having excellent molding processability and mechanical properties and excellent heat resistance, and an electric wire and a cable using the flame-retardant resin composition are provided. The challenge is to provide.

As a result of diligent studies to solve the above problems, the present inventors have obtained 90% by mass or more of the resin component in a flame-retardant resin composition in which a metal hydrate is mixed with the resin component in ethylene-acetic acid. A vinyl copolymer and a compatibilizer containing a polyolefin resin modified with a polar group-containing compound and a polar group-containing ternary copolymer are used, and the ratio of the metal hydrate is set to the ethylene-vinyl acetate copolymer weight. When the total amount is 150 to 250 parts by mass with respect to 100 parts by mass of the coalescing and compatibilizer, the molding processability, mechanical properties and flame retardancy as a coating material for electric wires and cables are excellent, and particularly excellent heat resistance. The present invention has been completed based on the findings and these findings.

That is, according to the first invention of the present invention, it is a flame-retardant resin composition containing a resin component and a metal hydrate.
A total of 90 ethylene-vinyl acetate copolymers and a compatibilizer containing a polyolefin resin modified with a polar group-containing compound and a polar group-containing ternary copolymer in 100% by mass of the above resin components. Including mass% or more
A flame-retardant resin composition containing 150 to 250 parts by mass of the metal hydrate with respect to a total of 100 parts by mass of the ethylene-vinyl acetate copolymer and the compatibilizer is provided.

According to the second invention of the present invention, in the first invention, a flame-retardant resin containing 10 to 60% by mass of the polar group-containing ternary copolymer in 100% by mass of the total amount of the compatibilizer. The composition is provided.

According to the third invention of the present invention, in the first or second invention, the polyolefin-based resin modified with the polar group-containing compound contains a linear low-density polyethylene modified with maleic anhydride. A flame-retardant resin composition is provided.

According to the fourth invention of the present invention, in any one of the first to third inventions, the polar group-containing ternary copolymer contains an ethylene-acrylic acid ester-maleic anhydride ternary copolymer. A flame-retardant resin composition is provided.

According to the fifth invention of the present invention, in any one of the first to fourth inventions, a flame-retardant resin composition in which the metal hydrate is aluminum hydroxide is provided.

According to the sixth invention of the present invention, an electric wire or a cable using the flame-retardant resin composition of any one of the first to fifth inventions is provided.

According to the present invention, a flame-retardant resin composition having excellent molding processability, mechanical properties, resistance to heat deformation and excellent heat resistance, and electric wires and cables using the flame-retardant resin composition. Can be provided.

The flame-retardant resin composition of the present invention is a flame-retardant resin composition containing a resin component and a metal hydrate.
A total of 90 ethylene-vinyl acetate copolymers and a compatibilizer containing a polyolefin resin modified with a polar group-containing compound and a polar group-containing ternary copolymer in 100% by mass of the above resin components. Including mass% or more
The metal hydrate is contained in an amount of 150 to 250 parts by mass with respect to a total of 100 parts by mass of the ethylene-vinyl acetate copolymer and the compatibilizer.

The role of each of the above components contained in the flame-retardant resin composition of the present invention is that the ethylene-vinyl acetate copolymer, which is the base resin, secures durability and strength such as abrasion resistance, and is a flame retardant. The metal hydrate imparts flame retardancy, and the compatibilizer improves the compatibility between the base resin and the metal hydrate to ensure the fluidity and flexibility of the resin composition.
The flame-retardant resin composition of the present invention contains, as a compatibilizer, a polyolefin-based resin modified with a polar group-containing compound and a polar group-containing ternary copolymer in combination, and is contained in the resin component. When the total content of the ethylene-vinyl acetate copolymer and the compatibilizer and the content of the metal hydrate are the above-mentioned specific amounts, mechanical properties such as molding processability, tensile breaking strength and tensile breaking elongation are obtained. , And has an excellent balance of heat resistance.
The polyolefin-based resin modified with a polar group-containing compound as a compatibilizer and the polar group-containing ternary copolymer have compatibility with the base resin ethylene-vinyl acetate copolymer and metal hydrate, respectively. Although it improves, it is presumed that the compatibility mechanism is different. The polyolefin-based resin modified with the polar group-containing compound has a polyolefin-based main chain, and a polar group is bonded to the side chain. Therefore, the polyolefin-based resin modified with the polar group-containing compound has an anchor effect in which the polar group of the side chain faces the metal hydrate side and the main chain enters the base resin, the ethylene-vinyl acetate copolymer. By having it, it is presumed that the compatibility between the ethylene-vinyl acetate copolymer and the metal hydrate is improved. On the other hand, in the polar group-containing ternary copolymer, the polar groups randomly present in the molecular chain face the metal hydrate side, and the polar group-containing ternary copolymer covers the metal hydrate. As a result of the arrangement, it is presumed that the wettability with respect to the ethylene-vinyl acetate copolymer as the base resin is improved, and the compatibility between the ethylene-vinyl acetate copolymer and the metal hydrate is improved. In the flame-retardant resin composition of the present invention, these compatibilizers are used in combination, and different compatibilization mechanisms of each compatibilizer are combined to balance mechanical properties such as heat resistance and tensile elongation at break. It is estimated that it will be possible to take.
Further, the molded product obtained by extrusion molding the flame-retardant resin composition of the present invention has excellent strength and durability as a material for coating electric wires and cables. Further, since the flame-retardant resin composition of the present invention is halogen-free, it is economically advantageous to provide an excellent molded product that does not generate toxic halogen-containing gas even when burned in the event of a fire or waste incineration. It is possible.
The present invention will be described in detail below.
Unless otherwise specified, the notation indicating the range "x to y" shall include x and y in the range.

1. 1. Resin component The resin component used in the present invention is a matrix component for forming a molded product of the flame-retardant resin composition of the present invention, and is typically a thermoplastic thermoplastic resin, which is a thermoplastic elastomer. Including.
The flame-retardant resin composition of the present invention contains an ethylene-vinyl acetate copolymer and a compatibilizer as resin components, and is an ethylene-vinyl acetate copolymer and a phase as long as the characteristics of the present invention are not impaired. It may further contain other resin components different from the solubilizer.

1-1. Ethylene-vinyl acetate copolymer The ethylene-vinyl acetate copolymer used in the present invention preferably satisfies the following conditions (1) and (2).

<Condition (1): MFR>
The ethylene-vinyl acetate copolymer used in the present invention preferably has a melt flow rate (MFR) of more than 0.1 g / 10 minutes and 15 g / 10 minutes or less, more preferably 0.1 g / 10 minutes. More than minutes, 5.0 g / 10 minutes or less, more preferably more than 0.1 g / 10 minutes, 3.0 g / 10 minutes or less.
When the MFR of the ethylene-vinyl acetate copolymer is within this range, the flame-retardant resin composition of the present invention is preferable because it is excellent in processing characteristics when manufacturing an electric wire or a cable. On the other hand, if the MFR of the ethylene-vinyl acetate copolymer is 0.1 g / 10 minutes or less, the fluidity is insufficient during high-speed extrusion molding, and there is a risk that the molded product may have problems such as poor appearance. If the MFR of the ethylene-vinyl acetate copolymer is larger than 15 g / 10 minutes, it is difficult to improve the mechanical strength such as tear strength and tensile strength, and the melt tension during molding is insufficient, which causes resin breakage and poor appearance. May be.

In the present invention, the MFR of the thermoplastic resin is JIS K7210-1 (2014) "Plastic-How to obtain melt mass flow rate (MFR) and melt volume flow rate (MVR) of thermoplastic plastic-Part 1: Standard". The value when MFR is measured under the condition of 190 ° C. and 21.18N (2.16kg) load according to the "Test method".
The MFR of the thermoplastic resin can be controlled, for example, by adjusting the temperature and pressure during polymerization.

<Condition (2): Vinyl acetate content>
The ethylene-vinyl acetate copolymer used in the present invention preferably contains 5 to 30% by mass of vinyl acetate comonomer units in 100% by mass of all the constituent units of the copolymer, and preferably contains 15 to 30% by mass. More preferred. When the content of the vinyl acetate comonomer unit is within the above range, it is easy to secure flame retardancy as an electric wire or a cable.
In the present invention, the content of each structural unit in the copolymer may be an amount obtained from the amount of raw materials charged when synthesizing the copolymer.

The content of the ethylene-vinyl acetate copolymer is preferably 60 to 95% by mass, more preferably 70 to 90% by mass, based on 100% by mass of the resin component.

The ethylene-vinyl acetate copolymer can be produced, for example, by a known high-pressure radical polymerization method, and may be produced by either a tubular method or an autoclave method.

1-2. Compatibility agent In the present invention, the compatibility agent is a thermoplastic resin that improves the compatibility between the ethylene-vinyl acetate copolymer as the base resin and the metal hydrate described later, and has a polar group. It is preferably a plastic resin.
The polar group contained in the compatibilizer is at least one polar group selected from a carboxyl group, a carboxylic acid anhydride group, a hydroxyl group, an alkoxy group, a glycidyl group, a carbonyl group, an amino group and a trichlorosilyl group. However, it is preferable because the compatibility effect between the base resin ethylene-vinyl acetate copolymer and the metal hydrate is high. Above all, it is more preferable that it is at least one polar group selected from a carboxyl group and a carboxylic acid anhydride group.

The compatibilizer used in the present invention contains at least a polyolefin resin modified with a polar group-containing compound and a polar group-containing ternary copolymer (polar group-containing terpolymer).
The polyolefin-based resin modified with the polar group-containing compound and the polar group-containing ternary copolymer are both ethylene-vinyl acetate copolymer as a base resin and thermoplastic elastomer contained as necessary. It has good compatibility with other resin components of the above, and is excellent in the compatibility effect of improving the compatibility between these resin components and metal hydrate. Further, as described above, it is presumed that the polyolefin resin modified with the polar group-containing compound and the polar group-containing ternary copolymer have different compatibility mechanisms between the resin component and the metal hydrate. In the flame-retardant resin composition of the present invention, these compatibilizers are used in combination, and by combining different compatibility mechanisms of each compatibilizer, mechanical properties such as moldability, tensile elongation at break, and mechanical properties such as tensile elongation at break and It is estimated that it will be possible to balance heat resistance.

<Polyolefin resin modified with polar group-containing compound>
Examples of the polyolefin-based resin modified with the polar group-containing compound include (i) unsaturated carboxylic acid or a derivative thereof, (ii) epoxy group-containing compound, (iii) hydroxyl group-containing compound, and (iv) amino group-containing compound. , (V) Organic silane compound, (vi) A polyolefin-based resin modified with a polar group-containing compound such as an organic titanate compound.
The polyolefin-based resin modified with the polar group-containing compound is typically a resin obtained by modifying a polyolefin-based resin, which is a homopolymer or an ethylene-α-olefin copolymer, with the polar group-containing compound. ..

(I) Examples of the unsaturated carboxylic acid or a derivative thereof include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, furanoic acid, crotonic acid, vinylacetic acid and penthenic acid, maleic acid, fumaric acid, citraconic acid and itaconic acid. Examples thereof include α, β-unsaturated dicarboxylic acids such as acids or acid anhydrides, and metal salts thereof, and maleic anhydride is particularly preferable.
Examples of the epoxy group-containing compound include glycidyl acrylate, glycidyl methacrylate, monoglycidyl ester of itaconic acid, monoglycidyl ester of butentricarboxylic acid, diglycidyl ester of butentricarboxylic acid, triglycidyl ester of butentricarboxylic acid and α-chloroallyl. , Maleic acid, crotonic acid, fumaric acid and other glycidyl esters or vinyl glycidyl ether, allyl glycidyl ether, glycidyl oxyethyl vinyl ether, styrene-p-glycidyl ether and other glycidyl ethers, p-glycidyl styrene and the like. Particularly preferable ones include glycidyl methacrylate and allyl glycidyl ether.
Examples of the (iii) hydroxyl group-containing compound include 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and hydroxyethyl (meth) acrylate.
Examples of the (iv) amino group-containing compound include tertiary amino group-containing compounds such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, and dibutylaminoethyl (meth) acrylate.
Examples of the (v) organic silane compound include vinyltrimethoxylane, vinyltriethoxysilane, vinyltriacetylsilane, vinyltrichlorosilane and the like.
Examples of the (vi) organic titanate compound include tetraisopropyl titanate, tetra-n-butyl titanate, tetrakis (2-ethylhexoxy) titanate, and titanium lactate ammonium.
Among these, (i) unsaturated carboxylic acid or a derivative thereof is preferable, and maleic anhydride is particularly preferable.

In the polyolefin-based resin modified with the polar group-containing compound, as the polyolefin-based resin used for modification, for example, an ethylene homopolymer, an ethylene-α-olefin copolymer, a mixture thereof, or the like can be used. Among them, ethylene homopolymers having a density of 0.87 g / cm ³ or more and 0.97 g / cm ³ or less and ethylene homopolymers having a density of 0.87 g / cm ³ or more and 0.97 g / cm ³ or less are excellent in that they have an excellent compatibility effect between the base resin ethylene-vinyl acetate copolymer and metal hydrate. At least one selected from ethylene-α-olefin copolymers is preferable, and ethylene-α-olefin copolymers having a density of 0.87 g / cm ³ or more and 0.97 g / cm ³ or less are more preferable.

Among the polyolefin resins modified with the polar group-containing compound, the linear low-density polyethylene modified with the polar group-containing compound has excellent compatibility between the polyolefin resin and the metal hydrate. It is preferable because it maintains heat resistance without impairing the flexibility of the soft resin, promotes the formation of a carbide layer during combustion, improves flame retardancy, and can be expected to improve mechanical strength. Further, (i) linear low-density polyethylene modified with unsaturated carboxylic acid or a derivative thereof is more preferable, and linear low-density polyethylene modified with maleic anhydride is particularly preferable.

The content of the structural unit derived from the polar group-containing compound in the polyolefin resin modified with the polar group-containing compound is preferably 0.05 to 10% by mass, more preferably 0.1 to 8.0% by mass. It is selected in the range of. If the content is less than 0.05% by mass, the compatibility effect between the ethylene-vinyl acetate copolymer as the base resin and the metal hydrate may be insufficient. If it exceeds 10% by mass, decomposition or cross-linking reaction may occur at the same time when the polyolefin resin is modified.

The melt flow rate (MFR) of the polyolefin-based resin modified with the polar group-containing compound is appropriately adjusted according to the molding method, and is not particularly limited, but the molding processability of the flame-retardant resin composition of the present invention and From the viewpoint of achieving both durability, it is preferably 0.01 to 20 g / 10 minutes, more preferably 0.02 to 10 g / 10 minutes, and more preferably 0.05 to 5 g / 10 minutes. More preferred.

The content of the polyolefin resin modified with the polar group-containing compound is not particularly limited, but from the viewpoint of heat resistance and molding processability, the content of the polar group-containing compound is contained in 100% by mass of the total amount of the compatibilizer. The modified polyolefin resin is preferably contained in a proportion of 40 to 90% by mass, more preferably in a proportion of 50 to 80% by mass.

The content of the polyolefin resin modified with the polar group-containing compound is preferably 1 to 30 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer and the compatibilizer. It is preferably 3 to 20 parts by mass, more preferably 5 to 18 parts by mass. By containing the polyolefin resin modified with the polar group-containing compound, the compatibility effect between the ethylene-vinyl acetate copolymer and the metal hydrate is improved, and the flame-retardant resin composition stretches at tensile strength. Mechanical properties such as are improved. If the content of the polyolefin resin modified with the polar group-containing compound is less than 1 part by mass, the compatibility effect may not be sufficiently exhibited, and if it exceeds 30 parts by mass, the flame-retardant tree composition. May become stiff and lose flexibility and flexibility, which may cause adverse effects such as reduced workability when winding wires or cables around the drum, and may reduce the long-term sustainability of physical properties. There is.

The polyolefin-based resin modified with the polar group-containing compound can be obtained, for example, by heating and mixing the polyolefin-based resin in the presence of the polar group-containing compound and the organic peroxide, and graft-modifying the resin. Further, those obtained by modifying the polyolefin resin so that the content of the structural unit derived from the polar group-containing compound is within the above range are preferably used.

<Polar group-containing ternary copolymer (polar group-containing terpolymer)>
The polar group-containing ternary copolymer used as a compatibilizer in the present invention is a ternary copolymer containing a polar group-containing structural unit.
In the above-mentioned polar group-containing ternary copolymer, the polar group contained in the polar group-containing structural unit is preferably an acidic group, and more preferably at least one selected from a carboxyl group and a carboxylic acid anhydride group.

As the polar group-containing ternary copolymer, a ternary copolymer of an acidic group-containing comonomer, an acid ester group-containing comonomer, and ethylene is particularly preferable. More specifically, for example, a ternary copolymer of ethylene, a radically polymerizable acid comonomer, one comonomer selected from an acrylic acid ester comonomer, a methacrylic acid ester comonomer, and a carboxylic acid vinyl ester comonomer is preferably used. be able to.

Specific examples of the radically polymerizable acid comonomer include α, β-unsaturated dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, and itaconic acid, and their acid anhydrides, acrylic acid, methacrylic acid, and crotonic acid. Examples thereof include unsaturated monocarboxylic acids such as acid, vinylacetic acid and penthenic acid, and maleic anhydride is preferable.
Specific examples of the acrylic acid ester comonomer include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate and the like, with methyl acrylate being preferred.
Specific examples of the methacrylic acid ester comonomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate and the like, with methyl methacrylate and ethyl methacrylate being preferred.
Specific examples of the carboxylic acid vinyl ester comonomer include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, and the like, with vinyl acetate being preferred.

Specific examples of the polar group-containing ternary copolymer include, for example, an ethylene-acrylate-methyl acrylate copolymer, an ethylene-acrylate-ethyl acrylate copolymer, and an ethylene-acrylate-vinyl acetate copolymer. Combined, ethylene-methacrylic acid-methyl methacrylate copolymer, ethylene-methacrylic acid-ethyl methacrylate copolymer, ethylene-methacrylic acid-vinyl acetate copolymer, ethylene-maleic anhydride-methyl acrylate copolymer, Ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, ethylene-maleic anhydride-ethyl methacrylate copolymer, ethylene-maleic anhydride-vinyl acetate copolymer Can be mentioned. Among them, ethylene-maleic anhydride-methyl acrylate copolymer, ethylene-maleic anhydride-ethyl acrylate copolymer, ethylene-maleic anhydride-methyl methacrylate copolymer, ethylene-maleic anhydride-ethyl methacrylate Ethylene- (meth) acrylic acid ester such as a copolymer-maleic anhydride ternary copolymer is preferable, ethylene-acrylic acid ester-maleic anhydride ternary copolymer is more preferable, and ethylene-acrylic anhydride alkyl ester- A ternary maleic anhydride copolymer is even more preferable, and a methyl ethylene-methyl acrylate-maleic anhydride ternary copolymer is particularly preferable.

In the polar group-containing ternary copolymer, the content of the comonomer is such that the content of the polar group-containing structural unit in the ternary copolymer, that is, the structural unit derived from the polar group-containing comonomer is 5 to 40% by mass. It is preferable to adjust so as to be. If the content of the polar group-containing structural unit is less than 5% by mass, the adhesiveness to the metal hydrate may be insufficient, and if it exceeds 40% by mass, the durability tends to decrease.
Further, in the polar group-containing ternary copolymer, the content of the structural unit derived from the acidic group-containing comonomer is preferably 0.05 to 10% by mass, preferably 0.1 to 8% by mass. Is more preferable.

The melt flow rate (MFR) of the polar group-containing ternary copolymer is appropriately adjusted according to the molding method and is not particularly limited, but is preferably 0.01 to 100 g / 10 minutes, preferably 0.02. It is more preferably ~ 80 g / 10 minutes, and even more preferably 0.05 to 50 g / 10 minutes. If the MFR of the polar group-containing ternary copolymer is less than 0.01 g / 10 minutes, the fluidity may be low and molding may be difficult, and if it exceeds 100 g / 10 minutes, impact resistance or durability may be deteriorated. It may decrease.

The content of the polar group-containing ternary copolymer is not particularly limited, but from the viewpoint of heat resistance and molding processability, 10 to 10 of the ternary copolymer is contained in 100% by mass of the total amount of the compatibilizer. It is preferably contained in a proportion of 60% by mass, more preferably in a proportion of 20 to 50% by mass.

The content of the polar group-containing ternary copolymer is preferably 1 to 30 parts by mass, more preferably 2 with respect to 100 parts by mass of the total of the ethylene-vinyl acetate copolymer and the compatibilizer. It is ~ 20 parts by mass, more preferably 3 to 10 parts by mass. If the content of the polar group-containing ternary copolymer is less than 1 part by mass, the compatibility effect may not be sufficiently exhibited, and mechanical properties such as tensile elongation at break may deteriorate, and 30 parts by mass. If it exceeds the above, the compatibility effect may be excessive, the material may become stiff, flexibility and flexibility may be lost, and adverse effects such as reduced workability when winding the electric wire or cable around the drum may occur. ..

The polar group-containing ternary copolymer can be produced by, for example, a tubular reactor, an autoclave reactor or the like by a high-pressure radical polymerization method or the like, but is produced by ionic polymerization. You may. Specifically, it can be produced according to the method for producing a copolymer described in Examples of JP-A-60-240705 and JP-A-8-113680.

<Other compatibilizers>
The compatibilizer further contains a polyolefin resin modified with the polar group-containing compound and other compatibilizers other than the polar group-containing ternary copolymer as long as the characteristics of the present invention are not impaired. You may be. Examples of other compatibilizers include ethylene such as ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, and ethylene-ethyl acrylate copolymer. A copolymer with (meth) acrylic acid or (meth) acrylic acid ester is preferably used.
When the compatibilizer contains the other compatibilizer, the content of the other compatibilizer is 20% by mass out of 100% by mass of the total amount of the compatibilizer from the viewpoint of suppressing a decrease in heat resistance. It is preferably less than or equal to, and more preferably 10% by mass or less.

In the flame-retardant resin composition of the present invention, the total amount of the compatibilizer is 100% by mass of the resin component.
It is preferably 5 to 30% by mass, more preferably 7 to 20% by mass.

1-3. Other Resin Components The resin components used in the present invention are 10% by mass or less of the total amount of the resin components, and other resin components other than the above ethylene-vinyl acetate copolymer and the above compatibilizer. May be further contained. For example, in the flame-retardant resin composition of the present invention, in order to maintain flexibility while containing a large amount of metal hydrate, as other resin components, non-modified other than the above ethylene-vinyl acetate copolymer It can contain at least one selected from polyolefin resins and thermoplastic elastomers.
Examples of the non-modified polyolefin-based resin include various polyethylene-based resins such as high-density polyethylene, low-density polyethylene, and ultra-low-density polyethylene.
Examples of the thermoplastic elastomer include ethylene propylene rubber (EPR) and ethylene propylene diene rubber (EPDM).
The content of the other resin components contained in the resin components is preferably 8% by mass or less, more preferably 5% by mass or less, and 3% by mass or less, based on 100% by mass of the total amount of the resin components. Is even more preferable.

2. 2. Metal Hydrate The metal hydrate used in the present invention is a compound having at least one of a metal element and a hydroxyl group or crystalline water, and is, for example, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, or basic carbonic acid. Examples thereof include metal hydroxides such as magnesium and hydrotalcite, and hydrates of silicates such as hydrated aluminum silicate and hydrated magnesium silicate. Among them, a metal hydroxide containing at least one selected from aluminum and magnesium and a hydrate thereof are preferable, aluminum hydroxide and magnesium hydroxide are more preferable, and aluminum hydroxide is most preferable. These metal hydrates can be used alone or in combination of two or more.
The metal hydrate used in the present invention is usually in the form of particles, and may further contain a small amount of surface treatment agent or impurities in addition to the above metal hydrate.

The aluminum hydroxide is not particularly limited, but the average particle size (D50) determined from the volume-based cumulative particle size distribution measured by the laser diffraction / scattering method is preferably 0.3 to 30 μm, which is more preferable. Is 0.5 to 15 μm, more preferably 0.5 to 5 μm. Further, in the total amount of aluminum hydroxide of 100% by mass, the content of particles having a particle size of 45 μm or more is preferably 0.5% by mass or less, and more preferably 0.4% by mass or less.

As the magnesium hydroxide, for example, magnesium hydroxide generally used as a flame retardant in a resin composition can be used. That is, magnesium hydroxide obtained by reacting magnesium chloride in seawater with a hydroxide as a raw material and performing steps such as sedimentation, washing, and concentration can be used. Specific examples of magnesium hydroxide include "Kisuma 5", "Kisuma 5A", "Kisuma 5B", and "Kisuma 5J" (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.).
Further, as the magnesium hydroxide, a known product such as a crushed product of a natural mineral (brucite) containing magnesium hydroxide as a main component can also be used.

The metal hydrate is preferably surface-treated with a surface treatment agent in order to improve dispersibility in the resin component, suppression of moisture absorption, deactivation of metal active sites, and the like. Examples of the surface treatment agent include fatty acids, fatty acid metal salts, and mixtures thereof, as well as fatty acid esters, fatty acid amides, waxes or modified products thereof, curable resins, organic silanes, organic titanates, and organic boranes.
In addition, polycarboxylic acid-based dispersants and polys as disclosed in JP-A-2002-167219, JP-A-2002-173682, JP-A-2003-003167, JP-A-2004-337698, and the like. Magnesium hydroxide surface-treated with a glycerin derivative, an N-acylbasic amino acid, an erythritol dibasic acid ester, a phosphoric acid ester, a phosphite ester, an alcohol phosphate ester, a phosphorus compound, or the like can also be used.
The surface treatment agent used for the surface treatment of the metal hydrate is not particularly limited, but is inexpensive and can effectively improve various properties. Therefore, fatty acids, fatty acid metal salts, fatty acids and fatty acid metals A mixture of salts, as well as fatty acid esters are preferred.

As the fatty acid, a saturated acid or unsaturated acid having 8 or more carbon atoms is desirable, and for example, octanoic acid, decanoic acid, myristic acid, behenic acid, palmitic acid, stearic acid, oleic acid, araquinic acid, palm oil, and beef tallow. , Soybean oil, palm oil, hydrogenated oil and the like.
Examples of the fatty acid metal salt include metal salts such as stearic acid, oleic acid, palmitic acid, linoleic acid, lauric acid, caprylic acid, behenic acid, and montanic acid. Examples of the metal used for the metal salt include Na, K, Al, Ca, Mg, Zn, Ba, Co, Sn, Ti, Fe and the like.
Examples of the fatty acid ester include methyl laurate, methyl mistylate, methyl palmitate, methyl stearate, methyl oleate, methyl erucate, methyl behenate, butyl laurate, butyl stearate, isopropyl mistylate, and palmitic acid. Examples include monoesters such as isopropyl, octyl palmitate, octyl coconut fatty acid, octyl stearate, octyl stearate, lauryl laurate, stearyl stearate, higher alcohol ester of long-chain fatty acid, behenyl behenate, and cetyl mistylate. , Neopentyl polyol long chain fatty acid ester and its partial esterified product, neopentyl polyol fatty acid ester, neopentyl polyol medium chain fatty acid ester, neopentyl polyol C9 chain fatty acid ester, dipentaerythritol long chain fatty acid ester, complex medium chain fatty acid Special fatty acid esters such as esters can also be mentioned.
These surface treatment agents can be used in any treatment method such as a wet method and a dry method. The amount of the surface treatment agent used is preferably in the range in which the amount of the surface treatment agent in 100% by mass of the metal hydrate is 1 to 10% by mass.

In the flame-retardant resin composition of the present invention, the content of the metal oxide may be 150 to 250 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer and the compatibilizer. It is preferably 170 to 230 parts by mass, more preferably 180 to 220 parts by mass, and further preferably 190 to 210 parts by mass. If the content of the metal hydrate is less than 150 parts by mass, the flame retardancy becomes insufficient, and if it exceeds 250 parts by mass, the material becomes brittle and hard, and the flexibility and mechanical strength of the product decrease. there is a possibility. The content of the metal hydrate may be an amount obtained from the amount of the metal hydrate charged.

3. 3. Other Components The flame-retardant resin composition of the present invention may further contain the above resin component and other components other than the above metal hydrate, if necessary, as long as the characteristics of the present invention are not impaired. ..
Examples of the other components include flame retardant aids, stabilizers, antioxidants, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, processability improvers, fillers, and copper damage inhibitors. Examples include various additives and auxiliary materials such as neutralizers, foaming agents, anti-whitening agents, anti-bubble agents, nucleating agents, coloring agents, lubricants, process oils, silicone oils, and carbon black.

Examples of flame-retardant aids include red phosphorus, antimony trioxide, antimony pentoxide, calcium phosphate, zircon oxide, titanium oxide, zinc oxide, magnesium oxide, calcium carbonate, magnesium carbonate, barium sulfate, barium borate, and barium borate. , Zinc oxide, zinc metaborate, molybdenum disulfide, clay, caustic soil, kaolinite, montmorillonite, hydrotalcite, talc, silica, white carbon, zeolite, hydromagnesite, organic bentonite and the like. The flame retardant aid may be used alone or in combination of two or more.
The content of the flame retardant aid is preferably 50 parts by mass or less with respect to 100 parts by mass of the metal hydrate.

The flame-retardant resin composition of the present invention may further contain a silicone oil. By containing silicone oil, screw squeal (high-pitched abnormal noise due to screw rotation) generated under high torque when kneading the flame-retardant resin composition is suppressed, thereby suppressing the flame-retardant resin composition and the flame-retardant resin composition. Damage to the kneader can be suppressed, and since it also serves as a flame retardant aid, deterioration of flame retardancy can be suppressed.
As the silicone oil, for example, dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, and modified silicone oil in which an organic group is introduced into these silicone oils are suitable.
When the flame-retardant resin composition of the present invention contains silicone oil, the content of the silicone oil is 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the ethylene-vinyl acetate copolymer and the compatibilizer. Is preferable. If the content of the silicone oil is less than 0.1 parts by mass, it is difficult to obtain the effect of the silicone oil, and if it exceeds 5 parts by mass, a problem may occur in workability.

Further, the flame-retardant resin composition of the present invention can be crosslinked by adding a cross-linking agent such as an organic peroxide, sulfur or a silane-based cross-linking agent, or a cross-linking aid. Further, the flame-retardant resin composition of the present invention can be crosslinked by irradiating with ionizing radiation or the like.

4. Characteristics of Flame Retardant Resin Composition The flame retardant resin composition of the present invention preferably has a high load melt flow rate (HLMFR) of 5 to 25 g / 10 minutes, preferably 5 to 20 g / 10 minutes. Is more preferable.
When the HLMFR of the flame-retardant resin composition is within the above range, it is preferable from the viewpoint of excellent processing characteristics when manufacturing an electric wire or a cable. On the other hand, if the HLMFR of the flame-retardant resin composition is less than 5 g / 10 minutes, the fluidity may be insufficient during high-speed extrusion molding, which may cause problems such as poor appearance of the molded product. If the HLMFR of the flame-retardant resin composition is larger than 25 g / 10 minutes, the mechanical properties may be insufficient, and the melt tension during molding may be insufficient, which may cause resin breakage or poor appearance.
In the present invention, the HLMFR of the resin composition is defined as JIS K7210-1 (2014) "Plastic-Thermal Plastic Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) -Part 1: Standard. It means the value when MFR is measured under the condition of 190 ° C. and 211.8N (21.6kg) load according to "Test method".
The HLMFR of the resin composition can be adjusted, for example, by the MFR and the content of each polymer contained in the resin composition.

5. Method for Producing Flame-Resistant Resin Composition The flame-retardant resin composition of the present invention is, for example, in addition to the above-mentioned ethylene-vinyl acetate copolymer, compatibilizer and metal hydrate, and if necessary, the above-mentioned other Ingredients are blended in any order in the above blending ratio, and ordinary single-screw extruder, twin-screw extruder, super mixer, Henschel mixer, Banbury mixer, roll mixer, brabender plastic, conider, kneader-ruder, etc. It can be produced by kneading and granulating using a kneader. In this case, it is preferable to select a kneading and granulating method capable of improving the dispersion of each component, and in particular, kneading and granulating using a Banbury mixer, a conider, a kneader ruder, and a twin-screw extruder. Is preferable from the viewpoint of economy and the like.

6. Applications The flame-retardant resin composition of the present invention can be used for, for example, electric wires, or cables such as electric power cables and optical fiber cables. The electric wire or cable using the flame-retardant resin composition of the present invention comprises, for example, a layer containing the flame-retardant resin composition of the present invention, typically the flame-retardant resin composition of the present invention. Examples include electric wires or cables having layers. Specifically, for example, an electric wire or a cable in which the insulating layer or the sheath layer contains the flame-retardant resin composition of the present invention can be mentioned. Further, it is provided in a usual electric wire or cable such as an inner semi-conductive layer or an outer semi-conductive layer coating layer, or, if desired, an outer metal shielding layer such as copper, aluminum, or lead, or a water-impervious layer wound with aluminum tape. An electric wire or cable whose coating layer contains the flame-retardant resin composition of the present invention can also be mentioned.
The method for producing an electric wire or cable using the flame-retardant resin composition of the present invention may be a general method, and the flame-retardant resin composition of the present invention is crosslinked by organic peroxide, silane crosslinking, or the like. However, it may be used in a non-crosslinked state or foamed, or may be used by laminating it with another base material such as a thermoplastic resin, a metal foil, a non-woven fabric, or a woven cloth, and is not particularly limited. ..

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples to demonstrate the excellence of the present invention and the superiority in the configuration of the present invention, but the present invention is limited by these examples. is not.
The measurement methods used in the examples and comparative examples are as follows.

(1) HLMFR
For the flame-retardant resin composition obtained by kneading, JIS K7210-1 (2014) "Plastic-Thermal Plastics Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) -Part 1: Standard HLMFR (High Road Melt Flow Rate) was measured under the condition of 190 ° C. and 211.8 N (21.6 kg) load according to the "Test Method".

(2) Tensile strength and tensile elongation at break JIS C3667 (2008) "Extrusion insulated power cables and their accessories for rated voltage 1KV～30kV - cables of rated voltage 0.6 / 1 kV" ST ₈ compound sheath defined by The tensile strength and elongation of (halogen-free) before and after aging were measured. Table 1 shows the minimum measured values measured before and after aging. From the viewpoint of mechanical properties, the minimum value of tensile breaking strength is preferably 9 MPa or more, and the minimum value of tensile breaking elongation is preferably 100% or more.
The test piece used for measuring the tensile breaking strength and the tensile breaking elongation was obtained by press-molding the flame-retardant resin composition obtained by kneading into a sheet having a thickness of 1 mm, and then JIS K6251 from the obtained sheet. It was obtained by punching out the No. 3 test piece.

(3) Heat Deformation Rate The measurement was carried out at 80 ° C. and 3 kg according to the measurement method specified in JIS C3005 (2014) “Rubber / Plastic Insulated Wire Test Method”. The smaller the heat deformation rate, the better the heat resistance. It is desirable that the heating deformation rate is 10% or less.
The test piece used for measuring the heat deformation rate was obtained by press-molding the flame-retardant resin composition obtained by kneading into a sheet having a thickness of 2 mm, and then pressing the obtained sheet into a sheet having a thickness of 2 mm × 15 mm width × 30 mm. Obtained by punching a plate-shaped test piece of length.

(4) Flame retardancy The oxygen index was measured according to JIS K7201-1 (1999). The larger the oxygen index, the better the flame retardancy. It is desirable that the oxygen index is 40% (volume fraction) or more.
The test piece used for measuring the oxygen index was obtained by press-molding the flame-retardant resin composition obtained by kneading into a sheet having a thickness of 3 mm, and then using the obtained sheet to obtain a thickness of 3 mm × a width of 6.5 mm ×. It was obtained by punching a rod-shaped test piece having a length of 150 mm.

(5) Comprehensive evaluation The flame-retardant resin composition was comprehensively judged according to the following numerical criteria.
As the moldability, the HLMFR is 5 to 20 g / 10 minutes, and as mechanical properties, the minimum value of the tensile strength is 9 MPa or more, and the minimum value of the tensile elongation at break is 100% or more, and heat resistance. As a flame retardant, the one having the above-mentioned heating deformation rate of 10% or less and the above-mentioned oxygen index of 40% or more was designated as “◯”.
As the moldability, the HLMFR is 5 to 25 g / 10 minutes, and as mechanical properties, the minimum value of the tensile strength is 9 MPa or more, and the minimum value of the tensile elongation at break is 100% or more, and heat resistance. As a flame retardant, the one having the above-mentioned heating deformation rate of 11% or less and the above-mentioned oxygen index of 40% or more was designated as “Δ”.
Those that do not correspond to the above "○" or "△" are designated as "×".

(Example 1)
Ethylene-vinyl acetate copolymer resin (manufactured by Nippon Polyethylene Co., Ltd., product name: Novatec EVA, grade: LV640) (MFR: 2 g / 10 minutes, vinyl acetate content: 25% by mass), 85.0 parts by mass, maleic anhydride 12.0 parts by mass of modified linear low-density polyethylene (MFR: 1.1 g / 10 minutes, maleic anhydride content: 1.0% by mass), ethylene-methyl acrylate-maleic anhydride ternary copolymer (Made by Nippon Polyethylene Co., Ltd., Product name: Lexpearl ET, Grade: 230X) (MFR: 8 g / 10 minutes, maleic anhydride content: 1.0% by mass, methyl acrylate content: 12% by mass). Flame retardant by mixing 0 parts by mass, 200 parts by mass of aluminum hydroxide (manufactured by HUBER, product name: MARTINAL OL-107LEO), and 2.0 parts by mass of silicone oil (manufactured by Shinetsu Chemical Industry Co., Ltd., product name: KF4917). A sex resin composition was produced, and the evaluation results of the resin composition are shown in Table 1.

(Examples 2 to 7, Comparative Examples 1 to 5)
A flame-retardant resin composition having the formulation shown in Table 1 was produced in the same manner as in Example 1, and the evaluation results of the resin composition are shown in Table 1.
In Example 5, magnesium hydroxide (manufactured by Konoshima Chemical Co., Ltd., product name: Magsees LN-6) was used as the metal hydrate.

Since the flame-retardant resin compositions of Examples 1 to 7 satisfy the requirements of the present invention, the HLMFR value is within a preferable range, the molding processability is excellent, and the strand appearance of the extruded product is good. Met. The flame-retardant resin compositions of Examples 1 to 7 were further excellent in mechanical properties, with values of tensile breaking strength and tensile breaking elongation being within preferable ranges. Further, the flame-retardant resin compositions of Examples 1 to 7 had a small heat deformation rate and were excellent in heat resistance, and had a large oxygen index and were also excellent in flame retardancy. Among them, Examples 1 to 6 in which a polyolefin-based resin modified with a polar group-containing compound and a polar group-containing ternary copolymer having a ratio of 10 to 60% by mass are used in combination as a compatibilizer have molding processability. And the heat resistance was further excellent. Further, the flame-retardant resin compositions of Examples 1 to 5 containing silicone oil are superior in flame retardancy to the flame-retardant resin compositions of Example 6 not containing silicone oil, and the resin is also contained. The screw squeal when kneading the composition was suppressed.
On the other hand, since the flame-retardant resin composition of Comparative Example 1 does not contain a compatibilizer, the tensile breaking strength is small and the mechanical properties are inferior, and the heat deformation rate is large and the heat resistance is inferior. It was.
The flame-retardant resin composition of Comparative Example 2 is inferior in flame retardancy because the amount of the metal hydrate compounded is small, and further, the tensile breaking strength is small and the mechanical properties are inferior. Was large and the heat resistance was also inferior.
The flame-retardant resin composition of Comparative Example 3 was inferior in mechanical properties due to the large amount of the metal hydrate compounded.
Since the flame-retardant resin composition of Comparative Example 4 did not contain a polar group-containing ternary copolymer as a compatibilizer, the tensile elongation at break was small and the mechanical properties were inferior.
The flame-retardant resin composition of Comparative Example 5 was inferior in molding processability because it did not contain a polyolefin-based resin modified with a polar group-containing compound as a compatibilizer.

As described above, the flame-retardant resin composition of the present invention is a molded product for electric wires or cables, which is excellent in molding processability, mechanical properties such as tensile breaking strength, and heat resistance. It has been clarified that it is a flame-retardant resin composition capable of providing economically advantageous. The flame-retardant resin composition of the present invention capable of economically and economically providing a molded product having such desirable properties, and the industrial value of electric wires and cables using the flame-retardant resin composition are extremely high. large.

Claims (6)

A flame-retardant resin composition containing a resin component and a metal hydrate.
A total of 90 ethanol-vinyl acetate copolymers, a polyolefin resin modified with a polar group-containing compound, and a compatibilizer containing a polar group-containing ternary copolymer in 100% by mass of the resin components. Including mass% or more
A flame-retardant resin composition containing 150 to 250 parts by mass of the metal hydrate with respect to 100 parts by mass of the total of the ethylene-vinyl acetate copolymer and the compatibilizer. The flame-retardant resin composition according to claim 1, wherein the polar group-containing ternary copolymer is contained in an amount of 100% by mass of 100% by mass of the compatibilizer. The flame-retardant resin composition according to claim 1 or 2, wherein the polyolefin-based resin modified with the polar group-containing compound contains a linear low-density polyethylene modified with maleic anhydride. The flame-retardant resin composition according to any one of claims 1 to 3, wherein the polar group-containing ternary copolymer contains an ethylene-acrylic acid ester-maleic anhydride ternary copolymer. The flame-retardant resin composition according to any one of claims 1 to 4, wherein the metal hydrate is aluminum hydroxide. An electric wire or cable using the flame-retardant resin composition according to any one of claims 1 to 5.