JP2002285010A - Thermoplastic resin composition for electric wire coating or sheath, and sheath and electric wire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition for electric wire coating or sheath which has excellent flame retardancy especially by shape maintenance in combustion and has excellent mechanical strengths and thermal properties, and is of advantage to separation from polyvinyl chloride resin, and an electric wire using it. SOLUTION: The thermoplastic resin composition used to electric wire coating or sheath contains a thermoplastic resin of 100 pts.wt., a phyllosilicate of 0.1-100 pts.wt., and a flame retardant assistant of 0.1-20 pts.wt. The flame retardant assistant is one selected from a group consisting of a carbon black, a fluororesin, a silicone oil, and a silicone-acrylic composite rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flame-retardant material,
Thermoplastic resin composition for wire coating or sheath, and
The present invention relates to a sheath and an electric wire using them.

[0002]

2. Description of the Related Art A resin for covering an electric wire and a resin for a sheath are required to be flame-retardant in order to prevent the spread of fire due to transmission of the electric wire in the event of a fire (JIS C 3005). For this reason, soft polyvinyl chloride has been conventionally used as a material for covering the electric wire and for the sheath.

[0003] In recent years, polymer materials used for industrial applications include waste plastic processing and environmental hormones.
There is a demand for materials that do not place a burden on the environment, and a switch to environmentally compliant materials is desired. Specifically, for example, conversion from polyvinyl chloride to a polyolefin resin has been studied due to problems such as generation of dioxin during combustion and toxicity of a plasticizer. For this reason, in recent years, in order to convert the electric wire to an environmentally compliant material, an electric wire using a polyolefin resin for the resin for covering the electric wire and a resin for the sheath, that is, a so-called eco electric wire has been developed.

[0004] However, polyolefin resins are
It is one of the most flammable resins, and developing flame retardancy is the most difficult task. At present, in many cases, a large amount of a flame retardant is kneaded into a polyolefin resin and used.

[0005] Among the flame retardants, halogen-containing flame retardants have a high flame retarding effect, and have a relatively small effect of lowering moldability and mechanical strength of molded articles. A large amount of halogen-based gas may be generated during processing or combustion, and the generated gas may corrode equipment or affect the human body. Do not use compounds,
A so-called non-halogen flame retardant treatment method is strongly desired.

As one of the non-halogen flame retardant treatment methods for polyolefin resins, a method of adding a metal compound such as aluminum hydroxide, magnesium hydroxide, or basic magnesium carbonate, which does not generate toxic gas upon combustion,
JP-A-57-165437, JP-A-61-363
No. 43, and the like. However, in order to impart sufficient flame retardancy to a flammable polyolefin resin, it is necessary to add a large amount of a metal compound. There was a problem that it was difficult to provide.

When only a metal hydroxide such as aluminum hydroxide or magnesium hydroxide is added to a polyolefin resin, a film layer cannot be formed during combustion, brittle ash is exposed, and combustion residue However, the material lost its function as a heat insulating layer at an early stage, and furthermore, the material was deformed, so that it was not possible to stop the spread of fire.

On the other hand, there has been proposed a method in which a phosphorus-based flame retardant is added to a polyolefin-based resin, a film is formed on the surface at the time of combustion, and the resulting oxygen barrier effect is used to exhibit flame retardancy. . However, in order to impart sufficient flame retardancy to the flammable polyolefin resin, it is necessary to add a large amount of a phosphorus-based flame retardant, and as a result, the mechanical strength of the obtained molded article is significantly reduced. However, there is a problem that it is difficult to put it to practical use.

When a phosphorus-based flame retardant is added to a polyolefin-based resin, a film is formed locally, but it is difficult to form a strong film layer as a continuous layer. The mechanical strength of the local coating is very weak, brittle ash is exposed during combustion, and combustion residues are dropped off, losing the function as a heat insulating layer early, and furthermore, the material is deformed. I could not stop the spread of fire.

Japanese Patent Application Laid-Open No. 6-15476 discloses a resin composition in which red phosphorus or a phosphorus compound and expandable graphite are added to a polyolefin resin. When this resin composition is viewed from the oxygen index, although it has sufficient flame retardancy, it can actually form a film only locally,
It was impossible to form a strong coating layer as a continuous layer. The mechanical strength of the local coating is very weak,
During combustion, brittle ash is exposed, and combustion residues fall off, so it loses its function as a heat insulating layer early.
The fire could not be stopped due to the deformation of the material.

In recent years, it has not contained halogen or phosphorus,
Silicone-based flame retardants have attracted attention as flame retardants that can be blended in a wide range of plastics and have high safety. It is known that a silicone-based flame retardant migrates to a resin surface during combustion and expresses flame retardancy by utilizing an oxygen barrier effect by forming a non-combustible coating. However, even when a silicone-based flame retardant is added to an olefin-based resin, the oxygen index is greatly improved, but a strong coating layer cannot be formed during actual combustion, and the flammable gas is generated from cracks in the incombustible coating. Can not stop the spread of fire.

[0012] In order to use these flame retardants in the resin for covering the electric wire or the resin for the sheath and to exhibit a predetermined flame retardancy, it is necessary to add a large amount of the flame retardant. It was difficult to secure the physical properties of the material. In addition, the addition of a large amount of a flame retardant increases the density, and the density is close to that of the polyvinyl chloride resin.

[0013]

DISCLOSURE OF THE INVENTION In view of the above situation, the present invention is a thermoplastic resin composition which retains its shape during combustion and exhibits a flame-retardant effect. It is another object of the present invention to provide a thermoplastic resin composition for covering or sheathing an electric wire, which is advantageous in separating from a polyvinyl chloride resin, and a sheath and an electric wire using them.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a thermoplastic resin composition used for coating or sheathing an electric wire, comprising 100 parts by weight of a thermoplastic resin, 0.1 to 100 parts by weight of a layered silicate, and A thermoplastic resin containing 0.1 to 20 parts by weight of a flame retardant, wherein the flame retardant is at least one selected from the group consisting of carbon black, fluororesin, silicone oil, and silicone-acryl composite rubber; A composition.

Furthermore, a thermoplastic resin composition used for covering or sheathing an electric wire, comprising 100 parts by weight of a thermoplastic resin, 1 to 20 parts by weight of a layered silicate, and 5 to 100 parts by weight of a non-halogen flame retardant. Containing, ASTM E 135
According to No.4, under a radiation heating condition of 50 kW / m ² ,
Combustion residue obtained by heating and burning for 0 min.
The yield point stress when compressed at 1 cm / sec is 4.9 × 10
^The present invention also includes a thermoplastic resin composition having a pressure of ³ Pa or more. Hereinafter, the present invention will be described in detail.

The thermoplastic resin used in the present invention is not particularly restricted but includes, for example, polyolefin resins, polystyrene resins, polyester resins, polyamide resins and the like. Among them, a polyolefin resin is preferably used.

Examples of the polyolefin resin include a homopolymer of ethylene or propylene, a random or block copolymer of ethylene and propylene, and a copolymer of ethylene or propylene with another α-olefin copolymerizable therewith. Polymer, copolymer of ethylene and vinyl acetate, copolymer of ethylene and (meth) acrylic acid or (meth) acrylate, copolymer of ethylene and styrene, homopolymer of butene, and isoprene Homopolymers, homopolymers or copolymers of dienes such as butadiene and the like can be mentioned. The (meth) acrylic acid is
Means acrylic acid or methacrylic acid.

Among these, ethylene homopolymer, propylene homopolymer, copolymer of ethylene or propylene with other α-olefin copolymerizable therewith, ethylene-ethyl acrylate copolymer, ethylene -A vinyl acetate copolymer is preferably used. As the other α-olefin, for example, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-
Methyl-1-pentene, butadiene and the like can be mentioned. These thermoplastic resins may be used alone or in combination of two or more.

The molecular weight and molecular weight distribution of the thermoplastic resin are not particularly limited, but the weight average molecular weight is 5,000 to 5
Preferably, it is 100,000, more preferably 20,000 to
The molecular weight distribution (weight average molecular weight / number average molecular weight) is preferably from 1.1 to 80, and more preferably from 1.5 to 40.

The layered silicate used in the present invention means a silicate mineral having exchangeable cations between layers. The layered silicate used in the present invention is not particularly limited, for example, montmorillonite, saponite, hectorite,
Examples include smectite-based clay minerals such as beidellite, stevensite, and nontronite, vermiculite, halloysite, and swellable mica. Above all, montmorillonite and swellable mica are preferred. The layered silicate may be a natural product or a synthetic product. These may be used alone or in combination of two or more.

As the above-mentioned layered silicate, it is more preferable to use smectites and swellable mica having a large shape anisotropy effect defined by the following formula from the viewpoint of improving the mechanical strength and gas barrier properties of the resin composition. . Shape anisotropy effect = Area of crystal surface (A) / Area of crystal end face (B)

The exchangeable cations existing between the layers of the above-mentioned layered silicate are ions such as sodium and calcium on the crystal surface. These ions have an ion-exchange property with a cationic substance. Can be trapped between the layers of the layered silicate.

The cation exchange capacity of the layered silicate is not particularly limited, but may be 50 to 200 milliequivalents / 100.
g is preferable. If the amount is less than 50 milliequivalents / 100 g, the amount of the cationic surfactant that can be trapped between the crystal layers by ion exchange decreases, and the interlayer may not be sufficiently nonpolarized. On the other hand, 200 milliequivalent /
If it exceeds 100 g, the bonding strength between the layers of the layered silicate becomes strong, and the crystal flakes may be difficult to peel off.

In the present invention, when a non-polar resin such as a polyolefin resin is used as the thermoplastic resin, the interlayer of the layered silicate is previously subjected to cation exchange with a cationic surfactant to make it hydrophobic. In addition, the affinity between the layered silicate and the thermoplastic resin can be increased, and the layered silicate can be uniformly finely dispersed in the thermoplastic resin.

The cationic surfactant is not particularly restricted but includes, for example, quaternary ammonium salts and quaternary phosphonium salts. Among them, a quaternary ammonium salt (alkylammonium ion) having an alkyl chain having 6 or more carbon atoms is preferably used because it can sufficiently depolarize the interlayer of the layered silicate.

Examples of the above quaternary ammonium salts include lauryl trimethyl ammonium salt, stearyl trimethyl ammonium salt, trioctyl ammonium salt, distearyl dimethyl ammonium salt, di-hardened tallow dimethyl ammonium salt, distearyl dibenzyl ammonium salt and the like. Can be Examples of the quaternary phosphonium salt include dodecyltriphenylphosphonium salt (DTPB), methyltriphenylphosphonium salt, lauryltrimethylphosphonium salt, stearyltrimethylphosphonium salt, trioctylphosphonium salt, distearyldimethylphosphonium salt, and distearyl. And dibenzylphosphonium salts.

The dispersibility of the layered silicate in a thermoplastic resin is improved by the above-described chemical treatment. The chemical treatment is not limited to (1) a cation exchange method using a cationic surfactant (hereinafter, referred to as a chemical modification (1) method), and may be carried out, for example, by various methods described below. it can. The layered silicate improved in dispersibility by the following chemical treatments, including the cation exchange method using the cationic surfactant, is referred to as an organized layered silicate.

(2) A hydroxyl group present on the crystal surface of the layered silicate which has been cation-exchanged by the above-mentioned cation exchange method is converted into a functional group capable of chemically bonding to the hydroxyl group or a chemical affinity without chemical bonding. (Hereinafter referred to as chemical modification (2) method).

(3) A hydroxyl group present on the crystal surface of the layered silicate that has been cation-exchanged by the above-mentioned cation exchange method is converted into a functional group capable of chemically bonding to the hydroxyl group or a chemical affinity without chemical bonding. (Hereinafter referred to as the chemical modification (3) method).

(4) A method of chemically modifying the crystal surface of the layered silicate that has been cation-exchanged by the above-mentioned cation exchange method with a compound having an anionic surface activity (hereinafter referred to as the chemical modification (4) method).

(5) Chemical Modification In the method (4), a compound having one or more reactive functional groups in addition to an anion site in a molecular chain of a compound having an anionic surfactant (hereinafter referred to as a chemical modification). Modification (5) method).

(6) In each of the above chemical modification methods (1) to (5), a functional group capable of reacting with the layered silicate, such as a maleic anhydride-modified polyolefin, may be added to the organically modified layered silicate. (Hereinafter referred to as a chemical modification (6) method) and the like. Each of the above methods may be used alone, or two or more methods may be used in combination.

In the above chemical modification (2), the functional group capable of chemically bonding to a hydroxyl group or the functional group having high chemical affinity without chemical bonding is not particularly limited, and examples thereof include an alkoxy group and an epoxy group. Group, carboxyl group (including dibasic acid anhydride), hydroxyl group, isocyanate group,
Examples include an aldehyde group and other functional groups having high chemical affinity with a hydroxyl group.

Examples of the compound having a functional group capable of chemically bonding to a hydroxyl group or a compound having a high chemical affinity without chemical bonding include silane compounds and titanate compounds having the functional groups exemplified above. Glycidyl compounds, carboxylic acids, alcohols and the like.

Examples of the silane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyl Dimethylmethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-
Aminopropyldimethylethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, N-β- (aminoethyl) γ-
Aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltriethoxysilane, N-
β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxy Silane, γ-methacryloxypropyltriethoxysilane, and the like.

In the chemical modification methods (4) and (5), a compound having anionic surface activity and / or one reactive functional group other than an anion site in a molecular chain is provided. The compound contained above is not particularly limited as long as it can chemically modify the layered silicate by ionic interaction, and includes, for example, sodium laurate, sodium stearate, sodium oleate,
Higher alcohol sulfates, secondary higher alcohol sulfates, unsaturated alcohol sulfates, and the like.

The above-mentioned layered silicate has an average interlayer distance of the (001) plane measured by a wide-angle X-ray diffraction measurement method of 3 nm or more, and is dispersed including those existing in 5 layers or less. preferable. When the average interlayer distance is 3 nm or more and 5 layers or less, it is advantageous for the development of performance such as flame retardancy, mechanical properties, and heat resistance.

In the present specification, the average interlayer distance of the layered silicate is an average interlayer distance when a fine flaky crystal is used as a layer, and is determined by X-ray diffraction peaks and transmission electron microscopy. Can be calculated by a wide-angle X-ray diffraction measurement method. The state in which the layers are cleaved to 3 nm or more and dispersed including those existing in 5 layers or less means that a part or all of the layered silicate laminate is dispersed, This is because the interaction between the layers is weakened.

Further, the average interlayer distance of the layered silicate is 6 nm.
Above is particularly advantageous for developing functions such as flame retardancy, mechanical properties, heat resistance and the like. When the average interlayer distance is 6 nm or more, the crystal flake layer of the layered silicate separates into layers, and the interaction of the layered silicate is weakened to a negligible level.
The state of dispersion of the crystalline flakes constituting the layered silicate in the resin proceeds in the direction of stabilization of crushing.

The dispersed state of the layered silicate is preferably such that 10% or more of the layered silicate is present in the thermoplastic resin composition in a state of being present in 5 layers or less. % Or more is present in a state of 5 layers or less. If the number of laminations is 5 or less, the above-mentioned effects can be obtained, but if the number is 3 or less, it is more preferable, and it is more preferable that they are dispersed in a single layer.

The layered silicate used in the present invention has an average interlayer distance of 3 nm or more, including those existing in 5 layers or less, and is dispersed. In some cases, it is considered that a sintered body is easily formed by the movement of the crystal flakes of the layered silicate. That is, the resin composition in which the layered silicate crystal flakes are dispersed at an average interlayer distance of 3 nm or more easily forms a sintered body that can be a flame-retardant film. Moreover, since this sintered body is formed at an early stage of combustion, not only the supply of oxygen from the outside but also the combustible gas generated by combustion can be shut off, and the thermoplastic resin composition of the present invention It becomes possible to exhibit flame retardancy.

The amount of the layered silicate is 0.1 to 100 parts by weight based on 100 parts by weight of the thermoplastic resin.
If the amount is less than 0.1 part by weight, it becomes difficult to form a sintered body, and the flame retardant effect becomes small. If the amount exceeds 100 parts by weight, the density of the obtained thermoplastic resin composition becomes high and practicality is lost. Will be More preferably, it is 1 to 20 parts by weight.

The means for dispersing the layered silicate in the thermoplastic resin composition of the present invention is not particularly limited.
A method using the above-mentioned organically modified layered silicate; a method in which a thermoplastic resin and a layered silicate are mixed by a conventional method and then foamed;
Examples include a method using a block copolymer as a dispersant. By using these dispersion methods, more uniform and fine dispersion can be achieved.

The flame retardant aid used in the present invention is carbon black, fluororesin, silicone oil, silicone-acryl composite rubber. These flame retardant aids may be used alone or in combination of two or more. By adding a flame retardant auxiliary to the thermoplastic resin composition,
The oxygen index can be improved and the maximum heat generation rate can be significantly reduced. By using carbon black, fluororesin, silicone oil, and silicone-acryl composite rubber as the flame retardant aid, decomposition of the resin can be prevented and the maximum heat generation can be suppressed. The silicone oil and silicone-acrylic composite rubber used in the present invention react with a polymer having an active group at the time of combustion to promote char formation, or protect when a glassy inorganic compound film is formed. It becomes strong as a material and further suppresses thermal decomposition of the resin.

Further, the fluororesin becomes fibrous in the resin composition by stretching at the time of melt molding, and the melt tension at the time of molding can be greatly improved. Thereby, the production rate of the olefin-based material can be improved. Similarly, even during combustion, by improving the melt viscosity of the fluororesin in the molten thermoplastic resin composition, drip (dropping of the molten resin) can be effectively suppressed, and a fire spread prevention effect can be imparted. . Further, this does not hinder the formation of a sintered film by the layered silicate during combustion, so that the flame retardancy is improved. The larger the fluorine substitution amount of the fluororesin, the more rigid the molecular structure becomes, and the more difficult it is to aggregate. Further, it is known that the fibers have a fibrous structure by stretching and become more rigid. On the other hand, carbon black is
The mechanism of action is unknown, but promotes char formation,
Significantly suppress fire.

The blending amount of the above flame retardant auxiliary is 1
It is 0.1 to 20 parts by weight with respect to 00 parts by weight. 0.1
If the amount is less than 10 parts by weight, it is difficult to exhibit good flame retardancy. If the amount is more than 20 parts by weight, the printability of the surface is deteriorated, and the mechanical strength such as increase in density and tensile strength is decreased. Disadvantages such as lack of flexibility against bending. Preferably, it is 0.5 to 15 parts by weight.

The thermoplastic resin composition of the present invention preferably contains a thermoplastic resin, a layered silicate, and a flame retardant auxiliary, and further contains a non-halogen flame retardant.

The non-halogen flame retardant is not particularly limited as long as it can impart flame retardancy.
For example, magnesium hydroxide, aluminum hydroxide, dawsonite, calcium aluminate, dihydrate gypsum,
Metal hydroxides such as calcium hydroxide. Of these, magnesium hydroxide and aluminum hydroxide are preferred. The metal hydroxide may be one that has been subjected to surface treatment with various surface treatment agents. The surface treatment agent is not particularly limited, and examples thereof include a silane coupling agent, a titanate coupling agent, a PVA surface treatment agent, and an epoxy surface treatment agent. These metal hydroxides may be used alone or in combination of two or more. When two or more metal hydroxides are used in combination, each of them initiates the decomposition and dehydration reaction at a different temperature, so that a higher flame retardant effect can be obtained.

The above-mentioned metal hydroxide has an effect of absorbing heat by causing an endothermic dehydration reaction under high heat during combustion and releasing water molecules, thereby lowering the temperature of the combustion field and extinguishing fire. In the thermoplastic resin composition of the present invention, the flame retardant effect of the metal hydroxide is increased by incorporating the layered silicate. This is considered to be due to the fact that the flame retardant effect due to the formation of a film during the burning of the layered silicate and the flame retardant effect due to the dehydration reaction of the metal hydroxide occur competitively, and each effect is promoted.

The amount of the non-halogen flame retardant is preferably 5 to 100 parts by weight based on 100 parts by weight of the thermoplastic resin. If the amount is less than 5 parts by weight, it is difficult to sufficiently exert the flame-retardant effect, and if it exceeds 100 parts by weight, although the flame-retardant effect is exhibited, disadvantages such as an increase in density and lack of flexibility tend to occur. More preferably, 20 to 6
0 parts by weight.

The method for preparing the thermoplastic resin composition of the present invention is not particularly limited. For example, a predetermined amount of a thermoplastic resin, a layered silicate, a non-halogen flame retardant, and a flame retardant auxiliary are directly blended. Mixing method: After mixing and mixing a layered silicate and a flame-retardant aid in a predetermined amount or more with a thermoplastic resin to prepare a masterbatch, heat the masterbatch so as to have a predetermined amount. A so-called master batch method in which a plastic resin and a non-halogen flame retardant are added and diluted is used.

The method for producing the thermoplastic resin composition of the present invention is not particularly limited, and various methods can be used. For example, a method of melt-kneading a thermoplastic resin and a layered silicate with an extruder, a two-roll, a Banbury mixer, etc .; a method of mixing both a thermoplastic resin and a layered silicate in an organic solvent in which both are dissolved; A method of polymerizing and mixing an olefin monomer using a layered silicate containing a metal complex, and the like, may be mentioned.

The transition metal complex is not particularly limited as long as it has the ability to polymerize olefinic monomers.
For example, metal complexes of groups 4, 5, 10, and 11 can be mentioned.

The thermoplastic resin composition of the present invention further comprises:
If necessary, additives may be appropriately contained. The additives are not particularly limited, and include, for example, antioxidants, weathering agents, ultraviolet absorbers, lubricants, flame retardants, antistatic agents and the like. In addition, the thermoplastic resin composition of the present invention may contain a small amount of a substance that can serve as a crystal nucleating agent as an aid to homogenize the physical properties, and the crystal may be refined.

The thermoplastic resin composition of the present invention has an ASTM
According to E 1354, the maximum heating value when burning by heating for 30 minutes under the radiation heating condition of 50 kW / m ² is 3
It is preferably 50 kW / m ² or less. If the maximum heat generation rate is out of this range, sufficient flame retardancy may not be exhibited. More preferably, it is 300 kW / m ² or less.

The thermoplastic resin composition of the present invention preferably has an oxygen index of 24 or more. In addition to the maximum heat generation rate being within the above range, when the oxygen index is within this range, the effect in the flame retardancy test in various electric wire forms is sufficient flame retardancy that can more reliably exhibit. It can be said. More preferably, it is 26 or more, and still more preferably, 28 or more.

The thermoplastic resin composition of the present invention has a JIS
It passes the 60-degree inclined combustion test specified in C3005. If it fails, it is not practically suitable when the wire is used for covering or sheathing the wire.

The thermoplastic resin composition of the present invention has an ASTM
According to E 1354, the yield point stress when compressing at 0.1 cm / sec a combustion residue obtained by heating and burning for 30 minutes under a radiation heating condition of 50 kW / m ² is 4.9 × 10 It is preferably at least ³ Pa. 4.9
When the pressure is less than × 10 ³ Pa, the combustion residue is easily collapsed by a slight impact, and the conductive portion is exposed at the time of a fire, causing a risk of electric shock or short circuit, and it is difficult to secure conduction in a disaster.

In the present invention, the amount of the layered silicate is 1
In the case of ２０20 parts by weight, even if a non-halogen flame retardant is used instead of the flame retardant aid, the same flame retardancy is exhibited as long as the yield point stress of the combustion residue is within the above range. can do.

The thermoplastic resin composition of the present invention preferably has a modulus at a tensile elongation of 100% of 7 MPa or less. If it exceeds 7 MPa, it is difficult to secure physical properties such as flexibility and elongation required for electric wires and the like.

The thermoplastic resin composition of the present invention preferably has a density of 0.90 to 1.20 g / cm ³ .
If it exceeds 1.20, the density becomes close to that of the polyvinyl chloride resin or the like, so that it is difficult to separate the material from the polyvinyl chloride resin coating material at the time of separation and recovery.

The thermoplastic resin composition of the present invention is used for covering an electric wire or a sheath. By using the thermoplastic resin composition of the present invention for an electric wire coating or sheath, it is possible to obtain an electric wire which has high flame retardancy, does not emit harmful substances at the time of disposal, and does not burden the environment. A sheath and an electric wire using the thermoplastic resin composition of the present invention are also one of the present invention.

[0063]

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

Example 1 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
6 parts by weight, 7.7 parts by weight of maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin Co., Ltd.), swellable fluoromica organically treated with distearyl dimethyl quaternary ammonium salt (“Somasif MAE-100” manufactured by Corp Chemical Co., Ltd.) )) 7.7 parts by weight, 10 parts by weight of carbon black (“Asahi # 70” manufactured by Asahi Carbon Co., Ltd.), and 3.5 parts by weight of silicone-acrylic composite rubber (“METABLEN SX005” manufactured by Mitsubishi Rayon Co., Ltd.) Temperature 180
The mixture was melted and kneaded at ℃, and the extruded strand was pelletized with a pelletizer. 180 ° C.
Was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 1 mm, thereby obtaining a sample for evaluation. The flame retardant electric wire coated with the obtained thermoplastic resin composition was subjected to a 60-degree inclined combustion test specified in JIS C3005.

Example 2 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
6 parts by weight, 7.7 parts by weight of maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin Co., Ltd.), magnesium hydroxide (“Kisma 5” manufactured by Kyowa Chemical Industry Co., Ltd.)
J "), 40 parts by weight, 7.7 parts by weight of swellable fluoromica (" Somasif MAE-100 "manufactured by Corp Chemical) organically treated with distearyl dimethyl quaternary ammonium salt, carbon black (" Asahi # 70 ") 2 parts by weight were filled, melt-kneaded at a set temperature of 180 ° C., and the extruded strand was pelletized by a pelletizer.
The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wire covered with the obtained thermoplastic resin composition is JIS C 300
A 60-degree inclined combustion test specified in No. 5 was performed.

Example 3 In Example 2, polyethylene resin (“HB530” manufactured by Nippon Polychem) was used instead of 84.6 parts by weight of ethylene-ethyl acrylate copolymer (“A4200” manufactured by Nippon Polyolefin). An evaluation sample was prepared in the same manner except that 0.6 parts by weight was used.

Example 4 In Example 2, swellable fluoromica treated organically with distearyl dimethyl quaternary ammonium salt (“Somasif MAE-1” manufactured by Corp Chemical Co., Ltd.)
00 ") instead of 7.7 parts by weight, 7.7 parts by weight of montmorillonite treated with distearyl dimethyl quaternary ammonium salt (" New Esven D "manufactured by Toyshun Mining Co., Ltd.) and a silicone-acryl composite rubber (Mitsubishi Corporation) Rayon “METABLEN SX005”) except that 2 parts by weight were used.
A sample for evaluation was prepared in the same manner.

Example 5 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
15 parts by weight, maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin Co., Ltd.) 3.85
Parts by weight, 40 parts by weight of magnesium hydroxide ("Kisuma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.), swellable fluoromica organically treated with distearyl dimethyl quaternary ammonium salt ("Somasif MAE-100" manufactured by Corp Chemical). 0 parts by weight, carbon black ("Asahi # 70" manufactured by Asahi Carbon Co., Ltd.)
2 parts by weight are filled and melt-kneaded at a set temperature of 180 ° C.
The extruded strand was pelletized with a pelletizer. The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wire covered with the obtained thermoplastic resin composition is described in JIS C
A 60 degree inclined combustion test specified in 3005 was performed.

Example 6 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
15 parts by weight, maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin Co., Ltd.) 3.85
14. parts by weight, 40 parts by weight of magnesium hydroxide (“Kisma 5J” manufactured by Kyowa Chemical Industry Co., Ltd.), swellable fluoromica organically treated with distearyldimethyl quaternary ammonium salt (“Somasif MAE-100” manufactured by Corp Chemical) 0 parts by weight, carbon black ("Asahi # 70" manufactured by Asahi Carbon Co., Ltd.)
2 parts by weight are filled and melt-kneaded at a set temperature of 180 ° C.
The extruded strand was pelletized with a pelletizer. The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wire covered with the obtained thermoplastic resin composition is described in JIS C
A 60 degree inclined combustion test specified in 3005 was performed.

(Comparative Example 1) Ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
Parts by weight, only 40 parts by weight of magnesium hydroxide ("Kisuma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.) and 2 parts by weight of carbon black ("Asahi # 70" manufactured by Asahi Carbon Co., Ltd.) and set at a temperature of 18
After melt-kneading at 0 ° C., a sample for evaluation was prepared in the same manner as in Example 2.

(Comparative Example 2) The swelling property of Example 3 was adjusted to 0.05 parts by weight of carbon black (“Asahi # 70” manufactured by Asahi Carbon Co., Ltd.) and organically treated with distearyl dimethyl quaternary ammonium salt. Instead of 7.7 parts by weight of fluorinated mica (“Somasif MAE-100” manufactured by Corp Chemical), 7.7 parts by weight of an unorganized swellable fluoromica (“Somasif ME-100” manufactured by Corp Chemical) are used. A sample for evaluation was prepared in the same manner as in Example 3 except for the fact that the sample was used.

Example 7 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
3 parts by weight, 40 parts by weight of magnesium hydroxide ("Kisma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.), swellable fluoromica organically treated with distearyl dimethyl quaternary ammonium salt ("Somasif MAE-100" manufactured by Corp Chemical) 7 0.7 parts by weight and 2 parts by weight of a silicone-acrylic composite rubber (“METABLEN SX005” manufactured by Mitsubishi Rayon Co., Ltd.) were filled, melt-kneaded at a set temperature of 180 ° C., and the extruded strands were pelletized by a pelletizer. The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. Also,
The flame-retardant electric wire covered with the obtained thermoplastic resin composition is specified in JIS C 3005 as 60.
A degree-gradient combustion test was performed.

Example 8 An ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
6 parts by weight, 7.7 parts by weight of maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin Co., Ltd.), magnesium hydroxide (“Kisma 5” manufactured by Kyowa Chemical Industry Co., Ltd.)
J ") 40 parts by weight, montmorillonite treated with distearyl dimethyl quaternary ammonium salt (" New Esven D "manufactured by Toyoshun Mining Co., Ltd.) 7.7 parts by weight, silicone-acryl composite rubber (" METABLEN SX005 "manufactured by Mitsubishi Rayon Co., Ltd.) 2
A part by weight was filled, melt-kneaded at a set temperature of 180 ° C., and the extruded strand was pelletized by a pelletizer. The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wires covered with the obtained thermoplastic resin composition are described in JIS C 3
A 60-degree inclined combustion test specified in 005 was performed.

(Example 9) In Example 8, distearyl dimethyl quaternary ammonium salt was treated in place of 7.7 parts by weight of montmorillonite treated with distearyl dimethyl quaternary ammonium salt ("New Esven D" manufactured by Toyshun Mining Co., Ltd.). 7.7 parts by weight of a swellable fluoromica ("Somasif MAE-100" manufactured by Corp Chemical Co., Ltd.) organically treated with a silicone resin, instead of 2 parts by weight of silicone-acrylic composite rubber ("METABLEN SX005" manufactured by Mitsubishi Rayon Co., Ltd.) Oil (“KF96H-1000000” manufactured by Shin-Etsu Chemical Co., Ltd.) 2
An evaluation sample was prepared in the same manner except that parts by weight were used.

Example 10 An evaluation sample was prepared in the same manner as in Example 9 except that the amount of magnesium hydroxide ("Kisma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.) was changed from 40 parts by weight to 20 parts by weight. Was prepared.

Example 11 An evaluation sample was prepared in the same manner as in Example 9 except that the amount of magnesium hydroxide (“Kisma 5J” manufactured by Kyowa Chemical Industry Co., Ltd.) was changed from 40 parts by weight to 60 parts by weight. Was prepared.

Comparative Example 3 In Example 8, an ethylene-ethyl acrylate copolymer ("A" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
4200 ") 100 parts by weight, magnesium hydroxide (" Kisuma 5J "manufactured by Kyowa Chemical Industry Co., Ltd.) 40 parts by weight, silicone-acryl composite rubber (" METABLEN S "manufactured by Mitsubishi Rayon Co., Ltd.)
X005 ") Only 2 parts by weight were charged and melt-kneaded at a set temperature of 180 ° C, and thereafter, evaluation samples were prepared in the same manner.

Comparative Example 4 84.6 parts by weight of a polyethylene resin (“HB530” manufactured by Nippon Polychem), 7.7 parts by weight of a maleic anhydride-modified ethylene oligomer (“ER403A” manufactured by Nippon Polyolefin), magnesium hydroxide ( 40 parts by weight of "Kisma 5J" manufactured by Kyowa Chemical Industry Co., Ltd., 7.7 parts by weight of non-organized swellable fluoromica ("Somasif ME-100" manufactured by Corp Chemical), silicone-acryl composite rubber (manufactured by Mitsubishi Rayon Co., Ltd.) "METABLEN S
X005 ") Fill 0.05 parts by weight, set temperature 180
The sample was melted and kneaded at ℃, and thereafter, samples for evaluation were prepared in the same manner.

Example 12 An ethylene-ethyl acrylate copolymer (“A4200” manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder “TEX30” manufactured by Japan Steel Works, Ltd.
4.6 parts by weight, 7.7 parts by weight of maleic anhydride-modified ethylene oligomer ("ER403A" manufactured by Nippon Polyolefin Co., Ltd.), 40 parts by weight of magnesium hydroxide ("Kisuma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.), distearyl dimethyl quaternary 7.7 parts by weight of swellable fluorine mica organically treated with an ammonium salt (“Somasif MAE-100” manufactured by Corp Chemical),
Fill 2 parts by weight of silicone-acrylic composite rubber ("METABLEN SX005" manufactured by Mitsubishi Rayon Co., Ltd.) and set a temperature of 1
The mixture was melt-kneaded at 80 ° C., and the extruded strand was pelletized by a pelletizer. 18 pellets obtained
3mm thickness or 1m thickness by hot press adjusted to 0 ℃
m to form a sample for evaluation. The flame retardant electric wire coated with the obtained thermoplastic resin composition was subjected to a 60-degree inclined combustion test specified in JIS C3005.

(Example 13) Instead of 84.6 parts by weight of the ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin) in Example 12, a polyethylene resin ("HB530" manufactured by Nippon Polychem) was used. 8
After melt-kneading at 180 ° C. using 4.6 parts by weight, an evaluation sample was prepared in the same manner.

(Example 14) Ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
8.45 parts by weight, 3.85 parts by weight of an acid-modified block polymer (“CB-OM22” manufactured by Kuraray Co., Ltd.), 40 parts by weight of magnesium hydroxide (“Kisma 5J” manufactured by Kyowa Chemical Industry Co., Ltd.),
Montmorillonite treated with distearyl dimethyl quaternary ammonium salt ("New Esven D" manufactured by Toyshun Mining Co., Ltd.) 7.7
A part by weight was filled, melt-kneaded at a set temperature of 180 ° C., and the extruded strand was pelletized by a pelletizer. The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wires covered with the obtained thermoplastic resin composition are described in JIS C 3
A 60-degree inclined combustion test specified in 005 was performed.

Example 15 Ethylene-ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) was placed in a small extruder "TEX30" manufactured by Japan Steel Works, Ltd.
4.6 parts by weight, 7.7 parts by weight of maleic anhydride-modified ethylene oligomer ("ER403A" manufactured by Nippon Polyolefin Co., Ltd.), 40 parts by weight of magnesium hydroxide ("Kisuma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.), distearyl dimethyl quaternary 7.7 parts by weight of ammonium salt-treated montmorillonite ("New Esven D" manufactured by Toyshun Mining Co., Ltd.) and 5 parts by weight of a fluorine-containing resin ("METABLEN S-2000" manufactured by Mitsubishi Rayon Co., Ltd.) are charged, and the temperature is set to 180 ° C. The resulting strand was melt-kneaded, and the extruded strand was pelletized with a pelletizer. The thickness of the obtained pellets was 3
It was molded into a plate having a thickness of 1 mm or 1 mm to obtain a sample for evaluation. The flame-retardant electric wire covered with the obtained thermoplastic resin composition was subjected to a 60-degree inclined combustion test specified in JIS C 3005.

Example 16 In Example 15, the amount of the ethylene-ethyl acrylate copolymer (“A4200” manufactured by Nippon Polyolefin Co., Ltd.) was changed to 88.45 parts by weight, and the maleic anhydride-modified ethylene oligomer (Nippon Polyolefin) was used. ER403A manufactured by Kuraray Co., Ltd. instead of 7.7 parts by weight
22 ") An evaluation sample was prepared in the same manner except that 3.85 parts by weight was used.

(Comparative Example 5) In Example 12, a small extruder “TEX30” manufactured by Nippon Steel Works, Ltd.
Only 100 parts by weight of an ethyl acrylate copolymer ("A4200" manufactured by Nippon Polyolefin Co., Ltd.) and 40 parts by weight of magnesium hydroxide ("Kisma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.) are filled and melt-kneaded at a set temperature of 180C. Thereafter, evaluation samples were prepared in the same manner.

(Comparative Example 6) In a small extruder “TEX30” manufactured by Nippon Steel Works, 84.6 parts by weight of a polyethylene resin (“HB530” manufactured by Nippon Polychem), and a maleic anhydride-modified ethylene oligomer (Nippon Polyolefin) Made "E
R403A)) 7.7 parts by weight, magnesium hydroxide (Kisuma 5J, manufactured by Kyowa Chemical Industry Co., Ltd.) 40 parts by weight, swellable non-organized fluorinated mica (Somasif ME-100, manufactured by Corp Chemical) 7.7. Set weight 1 using parts by weight
The mixture was melt-kneaded at 80 ° C., and the extruded strand was pelletized by a pelletizer. 18 pellets obtained
3mm thickness or 1m thickness by hot press adjusted to 0 ℃
m to form a sample for evaluation. The flame retardant electric wire coated with the obtained thermoplastic resin composition was subjected to a 60-degree inclined combustion test specified in JIS C3005.

Comparative Example 7 In a small extruder “TEX30” manufactured by Nippon Steel Works, 70 parts by weight of an ethylene-ethyl acrylate copolymer (“A4200” manufactured by Nippon Polyolefin Co., Ltd.) and a polypropylene resin (Nippon Polychem Co., Ltd.) were used. "EA"
9)) 10 parts by weight, 20 parts by weight of SEBS elastomer ("Toughtec H1052" manufactured by Asahi Kasei Corporation), and 170 parts by weight of magnesium hydroxide ("Kisuma 5J" manufactured by Kyowa Chemical Industry Co., Ltd.) are melted at a set temperature of 220 ° C. The kneaded and extruded strands were pelletized with a pelletizer.
The obtained pellet was formed into a plate having a thickness of 3 mm or 1 mm by a hot press adjusted to a temperature of 180 ° C. to obtain a sample for evaluation. The flame-retardant electric wire covered with the obtained thermoplastic resin composition is JIS C 300
A 60-degree inclined combustion test specified in No. 5 was performed.

Comparative Example 8 The amount of magnesium hydroxide was 7
An evaluation sample was prepared in the same manner as in Comparative Example 7, except that the amount was changed to 0 parts by weight.

The obtained evaluation sample was evaluated by the following method. (Measurement of average interlayer distance) The 2θ of the diffraction peak obtained from the diffraction of the lamination surface of the layered silicate in the composite was measured by an X-ray diffraction measurement device (“RINT1100” manufactured by Rigaku Corporation).
Using the Bragg diffraction equation below, the (00)
1) The surface spacing was calculated. λ = 2 dsin θ (λ = 1.54 d: interplanar spacing of layered silicate, θ: diffraction angle) d obtained by this equation was defined as the average interlayer distance.

(Layered State of Layer) Transmission Electron Microscope (TE
M JEOL Ltd. “JEM-1200EX II”) Observing the exfoliation state of the layered silicate in the composite by a photograph,
Those which were dispersed including those existing in 5 layers or less were evaluated as ○, and those in which 20% or more of the layered silicate were present in 5 layers or less were evaluated as ◎. Those having more than 5 layers were evaluated as x.

(Measurement of Maximum Heating Rate and Combustion Residue Strength) A test piece (100 mm × 100 mm ×) was measured in accordance with the burning test ASTM E 1354 (Testing method for flammability of building materials).
50 kW with a cone calorimeter
/ M2 and burned. The time from the start of heating to the ignition of the test piece was measured, and after burning, the residue generated was measured using a handy compression tester (KES-G5:
Yield point stress was measured by compression at 0.1 cm / sec by Kato Tech Co., Ltd.).

(Oxygen Index Measurement) Combustion Test ASTM D
Test specimens (70 mm × 6 mm × 3 m) according to 2863 (Standard test method for plastic flammability by oxygen index)
m thickness), and a combustion test was performed. The oxygen index is the minimum oxygen concentration, expressed as a percentage by volume of the gaseous mixture of oxygen and nitrogen required to maintain the combustion of the test piece. Continued, or when burning 50 mm within 3 minutes, it was determined that combustion could be maintained, and the oxygen concentration at that time was taken as the oxygen index of the test piece. That is, self-extinguishing occurs when the oxygen concentration is less than the oxygen index.

(Modulus at 100% tensile elongation) JIS under an atmosphere of temperature 20 ° C. and humidity 50% RH
In accordance with K 6251 "Tensile test method for vulcanized rubber", a dumbbell-shaped No. 4 test piece (thickness 1
mm) at 100% elongation.

(Density) The density of the thermoplastic resin composition for covering electric wires was measured according to a conventional method. The above results are shown in Tables 1 to 3.

[0094]

[Table 1]

[0095]

[Table 2]

[0096]

[Table 3]

When the evaluation of "yield point stress of combustion residue" in the table is "x", no combustion residue was formed, or the residue collapsed by a small force, so that the yield point stress was measured. Means that it was not possible.

[0098]

According to the thermoplastic resin composition for covering or covering an electric wire of the present invention, a sintered body is formed at the time of combustion by the above-mentioned constitution, and the shape of the combustion residue is maintained.
Thereby, shape collapse does not occur even after combustion, and it is possible to prevent fire spread. In addition, since the layered silicate can impart flame retardancy without being added in a large amount like a flame retardant, the mechanical properties before combustion are maintained, and the density of the thermoplastic resin does not increase, and the polyvinyl chloride resin is used. It is advantageous for the separation from the like. Therefore, it is suitably used as a material for preventing the occurrence of a fire using electric wires as a medium with such characteristics, and as a material that can be safely and inexpensively processed after disposal.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 27/12 C08L 27/12 83/04 83/04 H01B 3/00 H01B 3/00 A 3/44 3 / 44 FGMP 7/295 7/34 B (72) Inventor Akihiko Bando 2-1 Momoyama, Shimamotocho, Mishima-gun, Osaka Prefecture Inside Sekisui Chemical Co., Ltd. (72) Inventor Koichiro Iwasa Minami-ku, Kyoto 2-2 Toba-Kamichocho Sekisui Kagaku Kogyo Co., Ltd. F-term (reference) 4J002 AA01W AC14X BB03W BB04W BB06W BB07W BB12W BB14W BB15W BD12X CP03X DA037 DE048 DJ006 FD136 5G303 AA06 AB12 AB20 BA01 BA12 CA01 ACOA CAB1CA04 AB15 AB25 AB35 BA15 BA22 BA26 CA01 CA51 CC03 CC12 CD13 5G315 CA03 CB02 CB06 CC08 CD02 CD03 CD04 CD13 CD14

Claims (15)

[Claims] 1. A thermoplastic resin composition used for covering an electric wire or a sheath, comprising 100 parts by weight of a thermoplastic resin, 0.1 to 100 parts by weight of a layered silicate, and 0.1 of a flame retardant auxiliary.
Wherein the flame-retardant aid is at least one selected from the group consisting of carbon black, fluororesin, silicone oil, and silicone-acryl composite rubber. Composition. 2. The thermoplastic resin composition according to claim 1, further comprising 5 to 100 parts by weight of a non-halogen flame retardant. 3. A thermoplastic resin composition used for covering or sheathing an electric wire, comprising 100 parts by weight of a thermoplastic resin, 1 to 20 parts by weight of a layered silicate, and a non-halogen flame retardant.
0.1 to 100 parts by weight, in accordance with ASTM E 1354, a combustion residue obtained by heating and burning for 30 minutes under a radiant heating condition of 50 kW / m ² was 0.1 cm.
/ Yield stress at the time of compression, in seconds, is 4.9 × 10 ³ Pa
A thermoplastic resin composition as described above. 4. The layered silicate has an average interlayer distance of the (001) plane measured by a wide-angle X-ray diffraction measurement method of 3 nm or more, and is dispersed including five or less layers. The thermoplastic resin composition according to claim 1, 2 or 3, wherein 5. The thermoplastic resin is an ethylene homopolymer,
Propylene homopolymer, a copolymer of ethylene or propylene with another α-olefin copolymerizable therewith, an ethylene-ethyl acrylate copolymer, and ethylene-
5. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is at least one selected from the group consisting of vinyl acetate copolymers. 6. The thermoplastic resin composition according to claim 2, wherein the non-halogen flame retardant is a metal hydroxide. 7. The layered silicate is montmorillonite and / or
Or a swelling mica,
7. The thermoplastic resin composition according to 2, 3, 4, 5, or 6. 8. The thermoplastic resin composition according to claim 1, wherein the layered silicate contains an alkylammonium ion having 6 or more carbon atoms. 9. According to ASTM E 1354, 5
A maximum heating value of 350 kW / m ² or less when heated and burned for 30 minutes under a radiation heating condition of 0 kW / m ² , wherein the maximum heating value is 350 kW / m ² or less. 8
The thermoplastic resin composition according to the above. 10. The thermoplastic resin composition according to claim 9, wherein the oxygen index is 24 or more. 11. According to ASTM E 1354,
The yield point stress when compressing at 0.1 cm / sec the combustion residue obtained by heating and burning for 30 minutes under the radiation heating condition of 50 kW / m ² is 4.9 × 10 ³ Pa or more. Claims 1, 2, 4, 5, 6, 7,
11. The thermoplastic resin composition according to 8, 9, or 10. 12. The method according to claim 1, wherein the modulus at a tensile elongation of 100% is 7 MPa or less.
The thermoplastic resin composition according to 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11. 13. A density of 0.90 to 1.20 g / cm ^3.
Claim 1, 2, 3, 4, 5,
The thermoplastic resin composition according to 6, 7, 8, 9, 10, 11 or 12. 14. The method of claim 1, 2, 3, 4, 5, 6, 7,
A sheath comprising the thermoplastic resin composition described in 8, 9, 10, 11, 12 or 13. 15. The method of claim 1, 2, 3, 4, 5, 6, 7,
An electric wire comprising the thermoplastic resin composition according to 8, 9, 10, 11, 12 or 13.