JP5769099B2 - Non-halogen multilayer insulated wire - Google Patents

Description

  The present invention is excellent in wear resistance, hydrolysis resistance, flame retardancy, heat resistance, low smoke generation, electrical characteristics (DC stability), low toxicity, and especially non-halogen multilayer insulation conforming to EN standards (European standards) It relates to electric wires.

  Chloroprene rubber blends, chlorosulfone, which balances oil and fuel resistance, low-temperature properties, flame resistance, flexibility, and cost, are used for moving wires and cables used in railway vehicles and cables and cranes. Halogenated rubber blends such as chlorinated polyethylene blends, chlorinated polyethylene blends, and fluororubber blends are used.

  However, these halogen-containing substances generate a large amount of toxic and harmful gases during combustion, and generate extremely toxic dioxins depending on the incineration conditions. For this reason, from the viewpoint of safety at the time of fire and reduction of environmental burden, electric wires and cables using a halogen-free material (non-halogen material) that does not contain a halogen substance as a covering material have become widespread.

  On the other hand, in Europe where the railway vehicle network is developed, the adoption of the regional standard called EN standard (European standard) is spreading.

  In such EN standards, there is a risk of a major accident if there is a defect in a railway vehicle wire or cable. Therefore, wear resistance, hydrolysis resistance, flame resistance, heat resistance, low smoke generation, electrical characteristics ( Non-halogen materials with direct current stability) are required to be used for railway vehicle wires and cables.

  There exists an electric wire of patent document 1 as what responds to these requirements.

  In Patent Document 1, an inner layer made of a polyester resin composition containing a polyester resin (polybutylene terephthalate, polybutylene naphthalate, etc.), a polyester block copolymer, a hydrolysis inhibitor, and a calcined clay on the outer periphery of a conductor; A multilayer insulated wire comprising a polyester resin (polybutylene terephthalate, polybutylene naphthalate, etc.), a polyester block copolymer, a hydrolysis inhibitor, a calcined clay, and an outer layer made of a polyester resin composition containing magnesium hydroxide The polyester block copolymer comprises 20 to 70% by mass of a hard segment (a) containing terephthalic acid as a main component of polybutylene terephthalate having 60 mol% or more per dicarboxylic acid component, and an acid component constituting the polyester. Is an aromatic dicarboxylic acid Soft segment (a) 80 to 9 comprising 90 to 90 mol%, 6 to 12 carbon straight chain aliphatic dicarboxylic acid 1 to 10 mol%, and the diol component is a straight chain diol having 6 to 12 carbon atoms Polyester block copolymer having a melting point (T) in the range of the formula TO-5> T> TO-60 (TO: melting point of polymer comprising components constituting a hard segment) A multilayer insulated wire that is a coalesced is disclosed.

JP2011-228189A

  In addition to the above characteristics, the EN standard is also required to be excellent in low toxicity. However, in the prior art such as the above-mentioned Patent Document 1, it is a fact that an electric wire / cable having all these required characteristics including low toxicity cannot be obtained.

  Therefore, the object of the present invention is excellent in abrasion resistance, hydrolysis resistance, flame retardancy, heat resistance, low smoke generation, electrical characteristics (DC stability), low toxicity, and especially conforms to EN standard (European standard) An object of the present invention is to provide a non-halogen multilayer insulated wire.

In order to achieve the above object, the present invention provides the following halogen-free multilayer insulated wires [1] to [6].
[1] a conductor;
An inner layer coated with a polyolefin-based resin composition containing 60 to 95 parts by mass of high-density polyethylene, 5 to 40 parts by mass of an ethylene copolymer, and 0.1 to 1 part by mass of a metal harm preventing agent on the conductor;
A base polymer mainly composed of a polyester resin is included outside the inner layer, and the polyester block copolymer is 50 to 150 parts by mass and the hydrolysis inhibitor is 0.5 to 5 parts by mass with respect to 100 parts by mass of the base polymer. Part, an inorganic porous filler 0.5 to 5 parts by mass, and a non-halogen multilayer insulated wire comprising an outer layer coated with a polyester-based resin composition containing 10 to 30 parts by mass of magnesium hydroxide, the inner layer and the A non-halogen multi-layer insulated wire characterized in that the insulation thickness of two outer layers is 0.1 to 0.5 mm.
[2] The ethylene copolymer is an ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 9 to 35% by mass, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 45% by mass, and an ethylene-glycidyl methacrylate copolymer. The non-halogen multilayer insulated wire according to the above [1], which is at least one selected from polymers.
[3] The above [1] or [2], wherein the metal damage inhibitor is a copper damage inhibitor, and the copper damage inhibitor comprises at least one selected from a hydrazine derivative and a salicylic acid derivative. Non-halogen multilayer insulated wire described in 1.
[4] The non-halogen multilayer insulated wire according to any one of [1] to [3], wherein the polyester resin as a main component of the base polymer is polybutylene naphthalate or polybutylene terephthalate. .
[5] The non-halogen multilayer insulated wire according to any one of [1] to [4], wherein the hydrolysis inhibitor is an additive having a carbodiimide skeleton.
[6] The non-halogen multilayer insulated wire according to any one of [1] to [5], wherein the inorganic porous filler is fired clay.

  According to the present invention, non-halogen excellent in wear resistance, hydrolysis resistance, flame retardancy, heat resistance, low smoke generation, electrical characteristics (DC stability), low toxicity, and particularly compliant with EN standards (European standards) A multilayer insulated wire can be provided.

It is sectional drawing of the non-halogen multilayer insulated wire which concerns on embodiment of this invention. It is a figure for demonstrating the abrasion-resistance test method which tests the abrasion resistance of the electric wire in an Example. (A) is a side view, (b) is a front view. It is a figure for demonstrating the IEC combustion test method which tests the flame retardance of the electric wire in an Example.

(Configuration of non-halogen multilayer insulated wire)
FIG. 1 is a cross-sectional view of a non-halogen multilayer insulated wire according to an embodiment of the present invention.

  As shown in FIG. 1, the non-halogen multilayer insulated wire 1 according to the embodiment of the present invention has a conductor 10 and 60 to 95 parts by mass of high-density polyethylene, 5 to 40 parts by mass of ethylene copolymer, and metal damage prevention on the conductor 10. An inner layer 20 coated with a polyolefin-based resin composition containing 0.1 to 1 part by weight of an agent, and a base polymer containing a polyester resin as a main component on the outside of the inner layer 20, and 100 parts by weight of the base polymer Polyester containing 50 to 150 parts by mass of a polyester block copolymer, 0.5 to 5 parts by mass of a hydrolysis inhibitor, 0.5 to 5 parts by mass of an inorganic porous filler, and 10 to 30 parts by mass of magnesium hydroxide And an outer layer 30 coated with a resin-based resin composition, and an insulator thickness corresponding to two layers of the inner layer and the outer layer is 0.1 to 0.5 mm.

  As the conductor 10, the conductor generally used in the insulated wire can be used.

  The inner layer 20 will be described below.

The polyolefin resin composition used for the inner layer 20 contains 60 to 95 parts by mass of high-density polyethylene, 5 to 40 parts by mass of an ethylene copolymer, and 0.1 to 1 part by mass of a metal harm preventing agent.
<High density polyethylene>
The high-density polyethylene in the embodiment of the present invention is not particularly limited, but, for example, one having a density of 0.942 g / cm ³ or more is preferable. The high density polyethylene needs to be contained in the range of 60 to 95 parts by mass. The preferable content of the high-density polyethylene is 60 to 90 parts by mass, the more preferable content is 60 to 80 parts by mass, and the more preferable content is 60 to 70 parts by mass.
<Ethylene copolymer>
Examples of the ethylene copolymer in the embodiment of the present invention include ethylene-ethyl acrylate copolymer (EEA), ethylene-vinyl acetate copolymer (EVA), ethylene-styrene copolymer, ethylene-glycidyl methacrylate copolymer, ethylene- Butene-1 copolymer, ethylene-butene-hexene terpolymer, ethylene-propylene-diene terpolymer (EPDM), ethylene-octene copolymer (EOR), ethylene copolymer polypropylene, ethylene-propylene Copolymer (EPR), poly-4-methyl-pentene-1, maleic acid grafted low density polyethylene, hydrogenated styrene-butadiene copolymer (H-SBR), maleic acid grafted linear low density polyethylene, ethylene and Copolymer with α-olefin having 4 to 20 carbon atoms, Mainly composed of inic acid grafted ethylene-methyl acrylate copolymer, maleic acid grafted ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, butene-1. An ethylene-propylene-butene-1 terpolymer as a component can be used. Preferred are EEA, EVA and ethylene-glycidyl methacrylate copolymers. More preferred are EEA and EVA. These may be used alone or in combination of two or more. The ethylene copolymer needs to be contained in the range of 5 to 40 parts by mass. The preferable content of the ethylene copolymer is 10 to 40 parts by mass, and the more preferable content is 10 to 30 parts by mass.

The ethyl acrylate content (EA amount) of the ethylene ethyl acrylate copolymer is preferably 9 to 35% by mass, particularly in terms of flame retardancy and mechanical properties. In addition, the vinyl acetate content (VA amount) of the ethylene vinyl acetate copolymer is preferably 15 to 45% by mass particularly in terms of flame retardancy and mechanical properties.
<Metal harm prevention agent>
The metal harm preventing agent has an effect of stabilizing metal ions by chelate formation and suppressing oxidative degradation. Although the metal harm prevention agent in embodiment of this invention is not specifically limited, It is preferable that it is a copper harm prevention agent. It is preferable that a copper damage inhibitor consists of 1 or more types chosen from a hydrazine derivative and a salicylic acid derivative. 1,2-bis [3- (4-hydroxy-3,5-di-tert-butylphenyl) propionyl)] hydrazine (trade name: Irganox MD1024, IRGANOX is a registered trademark) is more preferable. It is necessary to contain a metal harm preventing agent in the range of 0.1 to 1 part by mass. The preferable content of the metal harm preventing agent is 0.3 to 1 part by mass, and the more preferable content is 0.5 to 1 part by mass. When the addition amount of the metal damage inhibitor is less than 0.1 parts by mass, the effect of suppressing metal damage is small, and when it exceeds 1 part by mass, dispersion failure occurs and mechanical properties are deteriorated.

  Next, the outer layer 30 will be described below.

  The polyester-based resin composition used for the outer layer 30 includes a base polymer mainly composed of a polyester resin, and 50 to 150 parts by mass of a polyester block copolymer with respect to 100 parts by mass of the base polymer. 0.5-5 parts by mass of the agent, 0.5-5 parts by mass of the inorganic porous filler, and 10-30 parts by mass of magnesium hydroxide.

The “base polymer mainly composed of a polyester resin” means that the polyester resin is the most abundant component in the base polymer. That is, it means that the content of the polyester resin in the base polymer is 50% by mass or more. Preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more. The reason for using the polyester resin is that it is excellent in heat resistance and wear resistance.
<Polyester resin>
Examples of the polyester resin include polybutylene naphthalate resin (PBN), polybutylene terephthalate resin (PBT), polytrimethylene terephthalate resin, polyethylene naphthalate resin, and polyethylene terephthalate resin. In the range which does not impair the effect of this invention, these can be used in combination and can be mixed and used for polypropylene resin, polyethylene resin, etc. A specific description will be given below using PBN and PBT as examples.

  The polybutylene naphthalate resin in the embodiment of the present invention is a polyester having naphthalene dicarboxylic acid, preferably naphthalene-2,6-dicarboxylic acid as a main acid component and 1,4-butanediol as a main glycol component, The polyester is such that all or most of the repeating units (usually 90 mol% or more, preferably 95 mol% or more) are butylene naphthalene dicarboxylate.

  The polybutylene naphthalate resin can copolymerize the following components as long as the physical properties are not impaired.

  Examples of the acid component include aromatic dicarboxylic acids other than naphthalenedicarboxylic acid, such as phthalic acid, isophthalic acid, terephthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylketonedicarboxylic acid, diphenylsulfide Examples include dicarboxylic acid, diphenylsulfone dicarboxylic acid, aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, and alicyclic dicarboxylic acid such as cyclohexane dicarboxylic acid, tetralin dicarboxylic acid, decalin dicarboxylic acid and the like.

  As glycol components, ethylene glycol, propylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, neopentyl glycol, cyclohexanedimethanol, xylylene glycol, diethylene glycol, polyethylene glycol, bisphenol A, catechol, resorcinol Examples include quinol, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, hydroquinone, dihydroxydiphenyl, dihydroxydiphenyl ether, dihydroxydiphenylmethane, dihydroxydiphenyl ketone, dihydroxydiphenyl sulfide, and dihydroxydiphenyl sulfone.

  Examples of the oxycarboxylic acid component include oxybenzoic acid, hydroxynaphthoic acid, hydroxydiphenylcarboxylic acid, and ω-hydroxycaproic acid.

  It should be noted that trifunctional or higher functional compounds such as glycerin, trimethylpropane, pentaerythritol, trimellitic acid, pyromellitic acid and the like may be copolymerized as long as the polyester does not substantially lose molding performance.

  Although there is no restriction | limiting in particular in the terminal carboxyl group density | concentration of the polybutylene naphthalate resin in this Embodiment, The smaller one is desirable.

  The polybutylene naphthalate resin is obtained by polycondensation of naphthalene dicarboxylic acid and / or a functional derivative thereof and butylene glycol and / or a functional derivative thereof using a conventionally known aromatic polyester production method.

  The polybutylene terephthalate resin in the embodiment of the present invention is a polyester having a repeating unit of butylene terephthalate as a main component, and 1,4-butanediol as a polyhydric alcohol component, terephthalic acid as a polyvalent carboxylic acid component or its It is a polyester having a main repeating unit of a butylene terephthalate unit obtained by using an ester-forming derivative. A main repeating unit means that a butylene terephthalate unit is 70 mol% or more in all the polyhydric carboxylic acid-polyhydric alcohol units. Further, the butylene terephthalate unit is preferably 80 mol% or more, more preferably 90 mol%, and still more preferably 95 mol% or more.

  Examples of polyvalent carboxylic acid components other than terephthalic acid used in polybutylene terephthalate resin include 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, isophthalic acid, phthalic acid, trimesic acid, trimellitic acid, etc. Aromatic polycarboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclics Examples thereof include dicarboxylic acids or ester-forming derivatives of the above polyvalent carboxylic acids (for example, lower alkyl esters of polyvalent carboxylic acids such as dimethyl terephthalate). These polyvalent carboxylic acid components may be used alone or in combination as a polyvalent carboxylic acid component other than terephthalic acid.

  Examples of polyhydric alcohol components other than 1,4-butanediol used in polybutylene terephthalate resin include ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, pentanediol, hexanediol, glycerin, trimethylolpropane, penta Aliphatic polyhydric alcohols such as erythritol, alicyclic polyhydric alcohols such as 1,4-cyclohexanedimethanol, aromatic polyhydric alcohols such as bisphenol A and bisphenol Z, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly And polyalkylene glycols such as tetramethylene oxide glycol. These polyhydric alcohol components may be used alone or as a polyhydric alcohol component other than 1,4-butanediol.

  The polybutylene terephthalate resin used in the present embodiment preferably has a terminal carboxyl group equivalent of 50 (equivalent / ton, hereinafter referred to as eq / t) or less, more preferably 40 from the viewpoint of hydrolysis resistance. (Eq / t) or less, more preferably 30 (eq / t) or less. When the terminal carboxyl group equivalent exceeds 50 (eq / t), it is not preferable from the viewpoint of hydrolyzability.

The polybutylene terephthalate resin in the embodiment of the present invention may be used singly as long as the effects of the present invention are exhibited, or may be used in a plurality of mixtures having different terminal carboxyl group concentrations, melting points, catalyst amounts, etc. Good.
<Polyester block copolymer>
The polyester resin composition used for the outer layer 30 includes a polyester block copolymer. The reason for adding the polyester block copolymer is to further increase the heat resistance and to provide flexibility.

  The polyester block copolymer needs to be added in the range of 50 to 150 parts by mass with respect to 100 parts by mass of the base polymer. More preferably, it is 60-100 mass parts. When the addition amount is less than 50 parts by mass, the heat resistance is lowered. On the other hand, when the addition amount exceeds 150 parts by mass, the elastic modulus of the material is lowered, and the mechanical properties, particularly the wear resistance, are markedly lowered.

  The polyester block copolymer used in the embodiment of the present invention has a hard segment of 60 mol% or more (preferably 70 mol% or more) containing polybutylene terephthalate as a main constituent, but in addition to benzene other than terephthalic acid. Or a diol such as an aromatic dicarboxylic acid containing a naphthalene ring, an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, an aliphatic diol having 2 to 12 carbon atoms other than tetramethylene glycol, and an alicyclic diol such as cyclohexanedimethanol. It may be polymerized, and the copolymerization ratio is less than 30 mol%, preferably less than 10 mol%, based on the total dicarboxylic acid. The smaller the copolymerization ratio, the higher the melting point and the better. However, copolymerization is also performed to increase flexibility. However, when the copolymerization ratio is increased, the compatibility between the polyester block copolymer and the polybutylene naphthalate resin is lowered, and the wear resistance may be impaired.

  On the other hand, the soft segment of the polyester block copolymer is 99 to 90 mol% aromatic dicarboxylic acid, 1 to 10 mol% linear aliphatic dicarboxylic acid having 6 to 12 carbon atoms, and the diol component is 6 to 6 carbon atoms. Polyester which is 12 linear diols. Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid. Examples of the linear aliphatic dicarboxylic acid having 6 to 12 carbon atoms include adipic acid and sebacic acid. The amount of the linear aliphatic dicarboxylic acid is preferably 1 to 10 mol%, more preferably 2 to 5 mol%, based on the total acid component of the polyester constituting the soft segment. If it is 10 mol% or more, the compatibility with the polybutylene naphthalate resin is lowered. Moreover, since the softness | flexibility of a soft segment will be impaired at 1 mol% or less, the softness | flexibility of this polyester-type resin composition is impaired as a result. Since the polyester constituting the soft segment needs to be amorphous or low crystalline, it is preferable to use isophthalic acid for 20 mol% or more of the total acid component constituting the soft segment. In addition, the soft segment can be copolymerized with some other components in the same manner as the hard segment. However, since the compatibility with the polybutylene naphthalate resin is lowered, the amount of the copolymer component is preferably 10 mol% or less, more preferably 5 mol% or less.

  In the polyester block copolymer used in the present embodiment, the mass ratio of the hard segment to the soft segment is preferably 20 to 50:80 to 50, more preferably 25 to 40:75 to 60. When the mass ratio of the hard segment is larger than the above range, it is not preferable because it becomes hard and difficult to use, and when the mass ratio of the soft segment is larger than the above range, the crystallinity is reduced and handling is difficult. This is not preferable.

  Moreover, the segment length of the soft segment and hard segment of the polyester block copolymer is preferably about 500 to 7000, more preferably 800 to 5000 when expressed in terms of molecular weight, but is not particularly limited. . Although it is difficult to directly measure the segment length, for example, the composition of the polyester constituting the soft segment and the hard segment, the melting point of the polyester comprising the components constituting the hard segment, and the obtained polyester block copolymer From the melting point, it can be estimated using the Flory equation.

  The melting point (T) of the polyester block copolymer is preferably in the range of “TO-5> T> TO-60” (TO: melting point of polymer composed of components constituting the hard segment). That is, the melting point (T) is preferably between TO-5 and TO-60, more preferably between TO-10 and TO-50, and even more preferably between TO-15 and TO-40. It is better to do so.

  Further, the melting point (T) is preferably 10 ° C. or more, preferably 20 ° C. or more higher than the melting point of the random copolymer. When the melting point of the random copolymer is not determined, the melting point (T) should be 150 ° C. or higher, preferably 160 ° C. or higher.

  When a random copolymer is used instead of the above polyester block copolymer, this polymer is generally amorphous and has a low glass transition temperature, so it is in a water tank shape, and the moldability is significantly reduced. The surface is not sticky and cannot be used as a real problem.

  The polyester block copolymer used in the present embodiment preferably has an intrinsic viscosity of 0.6 or more, more preferably 0.8 to 1.5, measured in 35 ° C. orthochlorophenol. If the intrinsic viscosity is lower than this, the strength is lowered, which is not preferable.

The production method of the polyester block copolymer used in the present embodiment is to produce a polymer constituting the soft segment and the hard segment, respectively, and melt-mix them so that the melting point is lower than that of the polyester constituting the hard segment. A method is mentioned. Since this melting point varies depending on the mixing temperature and time, it is preferable to deactivate the catalyst by adding a catalyst deactivator such as phosphoric acid when the target melting point is reached.
<Hydrolysis inhibitor>
The polyester resin composition used for the outer layer 30 contains a hydrolysis inhibitor.

  Suitable hydrolysis inhibitors used in the embodiments of the present invention include compounds having a carbodiimide skeleton such as dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride. However, it is not particularly limited.

The addition amount of the hydrolysis inhibitor is 0.5 to 5 parts by mass, preferably 0.5 to 4 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the base polymer. More preferably, it is 0.5-2 mass parts. This is because when the amount is less than 0.5 parts by mass, the hydrolysis resistance cannot be sufficiently exhibited, and when the amount added is more than 5 parts by mass, low toxicity cannot be achieved.
<Inorganic porous filler>
The polyester-based resin composition used for the outer layer 30 includes an inorganic porous filler. The reason for adding the inorganic porous filler is to further improve the electrical characteristics of the outer layer 30.

  The addition amount of the inorganic porous filler is 0.5 to 5 parts by mass, preferably 0.5 to 3 parts by mass, more preferably 0.5 to 2 parts by mass with respect to 100 parts by mass of the base polymer. More preferably, it is 0.5 to 1 part by mass. If the content is too small, ions cannot be trapped sufficiently, the insulation resistance becomes small, and the electrical characteristics are inferior. On the other hand, if the content is too large, the wear resistance is undesirably lowered.

The inorganic porous filler used in the embodiment of the present invention preferably has a specific surface area of 5 m ² / g or more.

The inorganic porous filler is preferably calcined clay, but is not limited thereto, and may be zeolite, mesalite, anthracite, pearlite foam, activated carbon, or may be surface treated with silane, fatty acid, or the like.
<Magnesium hydroxide>
The polyester resin composition used for the outer layer 30 includes magnesium hydroxide. The reason for adding magnesium hydroxide is to improve flame retardancy and to provide low smoke generation.

  The addition amount of magnesium hydroxide needs to be added in the range of 10 to 30 parts by mass with respect to 100 parts by mass of the base polymer. When the addition amount is less than 10 parts by mass, low smoke generation cannot be sufficiently exhibited, and when the addition amount is more than 30 parts by mass, flexibility and wear resistance are reduced when the wire is processed.

  Magnesium hydroxide used in the embodiment of the present invention is not particularly limited, and fatty acid, fatty acid metal salt, vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxy. Surface treatment may be performed with silane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, or the like, or an untreated product may be used.

  As a method of blending the above-mentioned various components into the resin composition used for the inner layer 20 and the outer layer 30, it can be performed by a known means at an arbitrary stage up to immediately before the coating step. The simplest method is a method of pelletizing high density polyethylene, ethylene copolymer, metal damage inhibitor, etc. by melt mixing extrusion, polyester resin and polyester block copolymer, hydrolyzable inhibitor, inorganic porous material A method in which a filler, magnesium hydroxide, and the like are pelletized by melt mixing extrusion is employed.

  As long as the effects of the present invention are exhibited, the resin composition used for the inner layer 20 and the outer layer 30 includes a pigment, a dye, a filler, a nucleating agent, a release agent, an antioxidant, a stabilizer, an antistatic agent, a lubricant, Other known additives can be blended and kneaded.

  In addition, as a manufacturing method of the multilayer insulated wire 1 which concerns on embodiment of this invention, the resin composition of the inner layer 20 and the resin composition of the outer layer 30 may be extrusion-coated by a separate process, and two layers are extrusion-coated simultaneously. May be. If necessary, the extrusion-coated multilayer insulated wire 1 may be irradiated and crosslinked.

  Insulators having a two-layer structure (inner layer 20 and outer layer 30) have an insulator thickness of two layers of 0.1 to 0.5 mm. The thickness of the inner layer 20 is preferably 0.05 to 0.2 mm, and the thickness of the outer layer 30 is preferably 0.05 to 0.3 mm.

  The multilayer insulated wire 1 according to the embodiment of the present invention is not limited to two layers as long as the inner layer 20 and the outer layer 30 are provided. The conductor 10 and the inner layer 20 are not limited as long as the effects of the present invention are achieved. An insulating layer may be interposed between them, and an intermediate layer may be provided between the inner layer 20 and the outer layer 30.

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

The multilayer insulated wire which concerns on Examples 1-12 and Comparative Examples 1-9 was produced as follows. Table 1 shows the composition of the inner layer resin composition and the outer layer resin composition of the multilayer insulated wire, and Table 2 shows the evaluation results for each.
[Materials used]
HDPE (High Density Polyethylene): Prime Polymer Co., Ltd., Hi-Zex 550P (Hi-Zex is a registered trademark)
-EEA (ethylene ethyl acrylate copolymer): manufactured by Nippon Polyethylene Corporation, Lexpearl EEA A1150 (Lexpearl is a registered trademark) (ethyl acrylate content: 15% by mass)
-EVA (ethylene-vinyl acetate copolymer): Mitsui-Dupont Polychemical Co., Ltd., Evaflex EV260 (Evaflex is a registered trademark) (vinyl acetate content: 28% by mass)
-EGMA (ethylene glycidyl methacrylate): manufactured by Sumitomo Chemical Co., Ltd., Bond Fast 2C (Bond Fast is a registered trademark)
* TMPTMA (trimethylolpropane trimethacrylate): Shin Nakamura Chemical Co., Ltd., NK Ester TMPT (H-200)
Metal damage inhibitor (copper damage inhibitor, 1,2-bis [3- (4-hydroxy-3,5-di-tert-butylphenyl) propionyl)] hydrazine): Ciba Japan Co., Ltd., IRGANOX MD1024 (IRGANOX is a registered trademark)
-Antioxidant: ADEKA Co., Ltd., ADK STAB AO-18 (ADK STAB is a registered trademark)
・ PBN (polybutylene naphthalate resin): TQB-OT, manufactured by Teijin Chemicals Limited
・ PBT (polybutylene terephthalate resin): Mitsubishi Engineering Plastics, Nova Duran 5026 (Nova Duran is a registered trademark)
-PEBC (polyester block copolymer): manufactured by Teijin Chemicals Ltd., Nouvelan TRB-EL2 (Nouvelan is a registered trademark)
・ Hydrolysis inhibitor: (Polycarbodiimide) Nisshinbo Co., Ltd., Carbodilite HMV-8CA (Carbodilite is a registered trademark)
・ Sintered clay: (Sintered calcined kaolin) manufactured by Engelhard, SATINTONE SP-33 (SATINTONE is a registered trademark)
Magnesium hydroxide: manufactured by Kyowa Chemical Industry Co., Ltd., Kisuma 5L (Kisuma is a registered trademark)

[Manufacture of multilayer insulated wires]
Regarding the obtained resin composition A and resin composition B, the resin composition A was dried at 80 ° C. for 8 hours or longer, the resin composition B was dried at 120 ° C. for 8 hours or longer in a hot air thermostatic bath, and then the diameter was about 0.00. Examples and comparative examples were obtained by directly extruding resin composition A with a coating thickness of 0.10 mm onto a 9 mm tin-plated annealed copper wire and further extruding resin composition B with a coating thickness of 0.15 mm on the outer periphery thereof. And the multilayer insulated wire of the prior art example was produced. For extrusion molding, dies and nipples each having a diameter of 4.2 mm and 2.0 mm were used. The extrusion temperature of the resin composition A was 150 ° C. to 170 ° C. for the cylinder portion and 170 ° C. for the head portion. The extrusion temperature of B was 250 ° C. to 280 ° C. for the cylinder part and 270 ° C. for the head part. The take-up speed was 10 m / min. Furthermore, the multilayer insulated wire was irradiated and crosslinked to obtain a finished product.

Abrasion resistance, hydrolysis resistance, flame retardancy, heat resistance, low smoke generation, electrical characteristics (DC stability), and low toxicity were evaluated as follows.
[Abrasion resistance test]
A short circuit is caused by reciprocating the manufactured multilayer insulated wire 1 (mounted on the gantry 43) in a room temperature atmosphere while applying a load 7N with the wear needle 42 of the wear tester 40 shown in FIGS. 2 (a) and 2 (b). The number of round trips was measured. The load was adjusted with the weight 41. The number of reciprocations of 150 times or more was accepted and less than 150 times was rejected.
[Hydrolysis resistance test]
The sample from which the conductor 10 of the produced multilayer insulated wire 1 was removed was allowed to stand for 30 days in a constant temperature and humidity chamber at 85 ° C./85% RH. Then, the winding test by a self-diameter was implemented, and the thing in which a crack does not generate | occur | produce was set as the pass ((circle)), and the thing in which a crack generate | occur | produced was set as the disqualified (x).
[Flame retardance test]
The produced multilayer insulated wire 1 was tested for flame retardancy in accordance with the IEC combustion test method (IEC603332-1). As shown in FIG. 3, the multilayer insulated wire 1 is vertically held by the upper support portion 1 a and the lower support portion 1 b, and the flame of the burner 50 is located at 475 ± 5 mm from the upper support portion 1 a with respect to the multilayer insulated wire 1. And after applying the flame for a specified burning time at an angle of 45 °, the burner 50 was removed, the flame was extinguished, and the carbonized portion 1c was examined.

Among the distances from the upper support part 1a to the carbonized part 1c, the distance to the upper part of the electric wire (α in FIG. 3) is 50 mm or more and the distance to the lower part of the electric wire (β in FIG. 3) is 540 mm or less. Anything other than the above range was regarded as rejected (x).
[Heat resistance test]
In the heat resistance test, the following heat aging test was performed.

Thermal aging test: In accordance with EN50305.7.7, the produced electric wire was heat-treated at 175 ° C./168 h in a thermostatic bath in a state of being wound around a mandrel. After that, it was left at room temperature, wound around a mandrel having a diameter about twice the outer diameter of the wire, and the insulator that did not crack was passed (○), and the cracked one was rejected (×). .
[Fume concentration test]
According to EN61034-2 (EN50268-2), the prepared electric wire was adjusted to 1 m, and 10 bundles of 7 twists were prepared and burned with alcohol fuel. The transmittance was measured by smoke generated at that time, and those with 70% or more were judged as acceptable (◯) and those with less than 70% were judged as unacceptable (x).
[Electrical characteristics (DC stability) test]
In accordance with EN 50305.6.7, DC 300 V is applied in 85 ° C., 3% NaCl aqueous solution. Electricity was continuously applied for 10 days, and those that did not break down were accepted (O), and those that failed were rejected (X).
[Toxicity test]
In accordance with EN50305.9.2, the conductor 10 of the multi-layer insulated wire 1 is extracted, the remaining inner layer 20 and outer layer 30 are cut into pieces, 1 g of the sample taken out is burned at 800 ° C., and five types of gases (CO, CO ₂ , HCN) are generated. , SO ₂ , NO _x ) were quantitatively analyzed, and converted into toxicity index (ITC value) by a predetermined weighting and evaluated. An ITC value of 6 or less was accepted (◯), and an ITC value greater than 6 was rejected (x).
[Comprehensive judgment]
Abrasion resistance, hydrolysis resistance, flame retardancy, heat resistance, low smoke generation, electrical properties (DC stability), and low toxicity evaluation results were all passed (○). One or more rejected (x) was regarded as rejected.

From Table 2, all of Examples 1 to 12 within the specified range of the present invention are wear resistance, hydrolysis resistance, flame resistance, heat resistance, low smoke generation, electrical characteristics (DC stability), In addition, it can be seen that it is excellent in low toxicity.

  On the other hand, in Comparative Example 1, since no ethylene copolymer is added to the inner layer formulation, the flame retardancy is insufficient and the required characteristics are not satisfied.

  In Comparative Example 2, since the addition amount of the ethylene copolymer blended in the inner layer is larger than the addition amount of the present invention, the wear resistance and DC stability do not satisfy the required characteristics.

  In Comparative Example 3, the polyester block copolymer blended in the outer layer is larger than the amount added according to the present invention, so that the required characteristics are not satisfied in terms of wear resistance.

  In Comparative Example 4, the polyester block copolymer blended in the outer layer is less than the amount added according to the present invention, so that the required characteristics are not satisfied in terms of heat resistance.

  Comparative Example 5 does not satisfy the required characteristics in the toxicity test because the hydrolysis inhibitor contained in the outer layer is larger than the amount added according to the present invention.

  Comparative Example 6 does not satisfy the required characteristics in terms of wear resistance and heat resistance because the amount of the outer layer-blended baked clay is larger than the amount added of the present invention.

  Comparative Example 7 does not satisfy the required characteristics in terms of toxicity, flame retardancy, and low smoke generation since the amount of magnesium hydroxide blended in the outer layer is less than that of the present invention.

  In Comparative Example 8, the amount of magnesium hydroxide blended in the outer layer is larger than the addition amount of the present invention, the surface of the electric wire is rough, and the required properties of wear resistance and heat resistance are not satisfied.

  In Comparative Example 9, since no metal damage inhibitor is added to the inner layer formulation, the heat resistance is insufficient and the required characteristics are not satisfied.

1: multilayer insulated wire, 10: conductor, 20: inner layer, 30: outer layer 40: wear tester, 41: weight, 42: wear needle, 43: mount 50: burner, 1a: upper support, 1b: lower support 1c: carbonization part

Claims (6)

Conductors,
An inner layer coated with a polyolefin-based resin composition containing 60 to 95 parts by mass of high-density polyethylene, 5 to 40 parts by mass of an ethylene copolymer, and 0.1 to 1 part by mass of a metal harm preventing agent on the conductor;
A base polymer mainly composed of a polyester resin is included outside the inner layer, and the polyester block copolymer is 50 to 150 parts by mass and the hydrolysis inhibitor is 0.5 to 5 parts by mass with respect to 100 parts by mass of the base polymer. Part, an inorganic porous filler 0.5 to 5 parts by mass, and a non-halogen multilayer insulated wire comprising an outer layer coated with a polyester-based resin composition containing 10 to 30 parts by mass of magnesium hydroxide, the inner layer and the A non-halogen multi-layer insulated wire characterized in that the insulation thickness of two outer layers is 0.1 to 0.5 mm.   The ethylene copolymer is an ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 9 to 35% by mass, an ethylene-vinyl acetate copolymer having a vinyl acetate content of 15 to 45% by mass, and an ethylene-glycidyl methacrylate copolymer. The non-halogen multilayer insulated wire according to claim 1, which is one or more selected.   The non-halogen multilayer according to claim 1 or 2, wherein the metal damage inhibitor is a copper damage inhibitor, and the copper damage inhibitor comprises at least one selected from a hydrazine derivative and a salicylic acid derivative. Insulated wire.   The non-halogen multilayer insulated wire according to any one of claims 1 to 3, wherein the polyester resin as a main component of the base polymer is polybutylene naphthalate or polybutylene terephthalate.   The non-halogen multilayer insulated wire according to any one of claims 1 to 4, wherein the hydrolysis inhibitor is an additive having a carbodiimide skeleton.   The non-halogen multilayer insulated wire according to any one of claims 1 to 5, wherein the inorganic porous filler is a fired clay.