JP2010157413A - Non-halogen flame retardant electric wire/cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high strength non-halogen flame-retardant electric wire capable of enhancing elastic modulus and strength. <P>SOLUTION: In the non-halogen flame-retardant electric wire covered with a non-halogen resin composition in which a flame-retardant agent such as magnesium hydroxide, aluminum hydroxide or the like with a surface treated with a silane coupling agent is added to an olefin based polymer, the resin composition in which the flame-retardant agent with the surface treated with the silane coupling agent having a molecular weight of 200 or more, preferably 240 or more and having a straight-chain molecular structure is mixed into the olefin based polymer is used for an insulating layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a non-halogen wire / cable having high strength.

  Conventionally, polyvinyl chloride (hereinafter referred to as PVC), which is inexpensive and highly flame retardant, has been widely used as an electric wire / cable coating material. However, since PVC contains a halogen element, generation of dioxins has been pointed out during incineration of waste electric wires, and non-halogenation has been strongly desired.

  Non-halogen flame retardant wires (including cables) include olefin polymers that do not contain halogen elements, flame retardants containing either or both of magnesium hydroxide and aluminum hydroxide, and melanin cyanurate, zinc borate and metal borate. Those containing a flame retardant aid such as salt are known.

  As an olefin polymer that does not contain a halogen element by the above-mentioned technology, in addition to polyethylene (hereinafter referred to as PE), an ethylene / ethyl acrylate copolymer (hereinafter referred to as PE) that forms a carbonized film having an oxygen barrier effect that is advantageous for flame retardancy during combustion. EEA) or ethylene vinyl acetate copolymer (hereinafter referred to as EVA) alone or blends are mainly used. Furthermore, it is known that the flame retardant and the flame retardant aid are used in combination in order to enhance the flame retardancy.

  For electric wires for equipment, a connector is attached to an electric wire end made of these resin compositions, but the above composition is easily deformed and easily broken because of its low elastic modulus and strength compared to conventional PVC. . When deformation or breakage occurs, the electric wires are likely to come out of the connector secondarily, the conductor is corroded, and electrical conduction failure occurs, which is a problem to be improved.

JP 2003-34793 A JP-A-7-176219

  In order to improve the strength of the non-halogen resin composition, a flame retardant surface-treated with a silane coupling agent is used.

  That is, magnesium hydroxide, aluminum hydroxide, etc. are hydrophilic and have poor binding to PE, EEA, EVA, etc., so that magnesium hydroxide, aluminum hydroxide, etc. are surface treated with a silane coupling agent to be hydrophobic. As a result, the bonding strength with PE, EEA, EVA, etc. is improved to increase the strength.

  However, even if a flame retardant surface-treated with a silane coupling agent is used, sufficient elastic modulus and strength are not obtained at present. Further, by making the average particle size of magnesium hydroxide or the like to be subjected to silane coupling treatment be 1.0 μm or less, particularly 0.5 μm or less, the dispersibility of the flame retardant is increased to increase the elastic modulus and strength. However, there is still a problem that sufficient strength cannot be obtained.

  An object of the present invention is to provide a non-halogen flame retardant electric wire / cable that can increase the elastic modulus and strength.

  In order to achieve the above object, the invention of claim 1 is coated with a non-halogen resin composition in which a flame retardant such as magnesium hydroxide or aluminum hydroxide, which has been surface-treated with a silane coupling agent, is added to an olefin polymer. In a non-halogen flame retardant electric wire, a resin composition in which a flame retardant having a molecular weight of 200 or more, preferably 240 or more, and surface-treated with a silane coupling agent having a linear molecular structure is mixed with an olefin polymer is used as an insulating layer. It is a non-halogen flame retardant electric wire / cable designed to be used.

  In the invention of claim 2, the silane coupling agent is selected from the group consisting of γ-methacryloxypropyltrimethoxysilane, n-hexadecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-ureidopropyltri 2. The non-halogen flame-retardant electric wire / cable according to claim 1, comprising ethoxysilane, γ-dibutylaminopropyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, or the like.

  Invention of Claim 3 mixed 40-300 weight part of magnesium hydroxide or aluminum hydroxide surface-treated with the silane coupling agent individually or in combination with 100 weight part of olefin polymer. Non-halogen flame retardant wire / cable.

  The invention of claim 4 is the non-halogen flame-retardant electric wire / cable according to any one of claims 1 to 3, wherein the particle size of magnesium hydroxide or aluminum hydroxide is 1.5 μm or less, preferably 1.0 μm or less.

  The invention according to claim 5 is the non-halogen flame retardant electric wire / cable according to any one of claims 1 to 4, wherein 1 to 30 parts by weight of a maleic acid copolymer is used in combination with the olefin polymer.

  In the present invention, when a flame retardant is treated with a silane coupling agent, a silane coupling agent having a molecular weight of 200 or more, preferably 240 or more and having a linear molecular structure is used as the silane coupling agent. The bond between the polyolefin-based copolymer and the flame retardant becomes good, and the elastic modulus and strength can be increased.

  Embodiments of the present invention will be described below.

  The present invention blends 100 parts by weight of an olefin polymer containing no halogen and 40 to 300 parts by weight of magnesium hydroxide or aluminum hydroxide surface-treated with a silane coupling agent, thereby providing high strength with excellent terminal processability. Non-halogen flame retardant wire / cable.

  Here, the surface roughness of the electric wire coated with the resin composition is 0.5 μm or less, the adhesion between the insulating layer and the conductor is 5 N / 25 mm or more, the elastic modulus of the conductor is 10 GPa or more, and the resin composition is ionized by radiation. It is preferable that it is subjected to crosslinking treatment.

  Examples of the olefin polymer used in the present invention include high, medium and low density polyethylene, polypropylene, ethylene / propylene / copolymer, ethylene / propylene / diene terpolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, linear low Examples include high-density polyethylene, ultra-low-density polyethylene, ethylene / vinyl acetate copolymer, ethylene / butene copolymer, ethylene / hexene copolymer, ethylene / methyl methacrylate copolymer, ethylene / octene copolymer, and styrene / ethylene / butylene / styrene copolymer. It is done.

  As the silane coupling agent for surface treatment of magnesium hydroxide and aluminum hydroxide, a silane coupling agent having a molecular weight of 200, preferably 240 or more, and having a linear molecular structure is used.

  As this linear silane coupling agent,

γ-methacryloxypropyltrimethoxysilane (molecular weight 248.4),

n-hexadecyltrimethoxysilane (molecular weight 346.7),

γ-glycidoxypropyltrimethoxysilane (molecular weight 236.3),

Vinyltriacetoxysilane (molecular weight 232.3),

γ-ureidopropyltriethoxysilane (molecular weight 264.5),

γ-dibutylaminopropyltrimethoxysilane (molecular weight 291.1),

n-decyltrimethoxysilane (molecular weight 262.5),

γ-diallylaminopropyltrimethoxysilane (molecular weight 259.5)

n-octadecyltrimethoxysilane and the like, and after spraying or impregnating magnesium hydroxide or aluminum hydroxide with a solution of these silane coupling agents, the surface of magnesium hydroxide or aluminum hydroxide is dried. A silane coupling agent can be attached to the substrate.

  In the present invention, the flame retardant is surface-treated with a silane coupling agent having a molecular weight of 200, preferably a molecular weight of 240 or more, and having a linear molecular structure, and this is mixed with an olefin polymer to form a linear chain. It is possible to increase the probability that the silane coupling agent and polyolefin are bonded to each other, thereby improving the elastic modulus and strength.

  The average particle diameter of flame retardants such as magnesium hydroxide and aluminum hydroxide is 1.5 μm or less, preferably 1.0 μm or less, and more preferably 0.5 μm or less.

  The amount of the flame retardant added is defined as 40 to 300 parts by weight. If the amount is less than 40 parts by weight, the flame retardancy is insufficient. If the amount exceeds 300 parts by weight, the flame retardant effect is small. This is because the elongation decreases.

  By subjecting the resin composition to a crosslinking treatment with ionizing radiation, the bonding force between the polymers increases, and the end workability can be further improved by improving the elastic modulus.

  In addition, a flame retardant aid, a colorant, carbon black, a crosslinking aid, a filler, a lubricant, and the like may be appropriately added to the above formulation.

  Next, examples of the present invention will be described together with comparative examples.

  First, the characteristics in the table were measured by the following method.

  The blended composition was prepared by kneading with a pressure kneader set at 150 ° C. (75 L pressure kneader manufactured by Moriyama). Using a 40 mm extruder maintained at 220 ° C., these blended compositions were extrusion coated to an outer diameter of 0.88 mm on seven strands having an outer diameter of 0.48 mm to prepare electric wire samples.

  Ionizing radiation crosslinking was performed with an electron beam crosslinking facility at an irradiation dose of 1 Mrad.

  Tensile strength, elongation, and elastic modulus are measured at a tensile speed of 200 mm / min using a tube with the core wire removed from the wire in accordance with JIS C-3005. The tensile strength is 10.5 MPa or more and the elongation is 150% or more. It was.

  The 50% modulus indicates a stress value (MPa) when an elongation of 50% is given.

  As for the scratch resistance, the scrape test and the cut-through test were evaluated as ◯ if they were equivalent, double circle if they were better than PVC, and x if they were inferior to PCV.

  For flame retardancy, a vertical flame test (VW-1) based on ULsubject 785 was conducted and the flame extinguished within 60 seconds was regarded as acceptable (O).

  Samples used in Examples and Comparative Examples are shown below.

The ultra-low density PE has a density of 0.9 g / cm ³ , MI: 0.8 g / 10 min, EVA has a VA content of 42%, MI: 0.2 g / 10 min, and EEA has an EA content. 15%, MI: 0.8 g / 10 min. Bondin LX4110 (trade name) was used as the maleic anhydride copolymer.

  As shown in Table 3, magnesium hydroxides A to E were obtained by changing the particle diameter and the silane coupling agent. Magnesium hydroxide A was γ-methacryloxypropyltrimethoxysilane (average molecular weight 248.4). Surface treated average particle size 0.8 μm, magnesium hydroxide B is n-hexadecyltrimethoxysilane (average molecular weight 346.7) surface treated average particle size 0.8 μm, magnesium hydroxide C, D is an average particle size of 1.5 μm and 2.0 μm surface-treated with γ-methacryloxypropyltrimethoxysilane (average molecular weight 248.4). Magnesium hydroxide E is vinyltrimethoxysilane (average molecular weight 148. 2) surface treated with an average particle size of 1.2 μm, and aluminum hydroxide is γ-methacryloxypropyltrimethoxysilane The average particle size is 0.8 μm which is surface-treated with (average molecular weight 248.4).

  Melamine cyanurate was used as the flame retardant aid, and tetrakis- (methylene-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate) methane) was used as the antioxidant.

  While Examples 1 to 13 (Table 1) all have good trauma resistance, Comparative Examples 1 to 3 (Table 2) were surface-treated with vinyltrimethoxysilane having an average molecular weight of 148.2. Since magnesium hydroxide E is used, the flame resistance is good, but the damage resistance is poor.

  In Comparative Example 4, magnesium hydroxide D surface-treated with γ-methacryloxypropyltrimethoxysilane having an average molecular weight of 248.4 is used. However, since the particle size is as large as 2.0 μm, the damage resistance is inferior.

  In the case of Comparative Examples 5 and 6 using magnesium hydroxide A, Comparative Example 5 with a small addition amount of 30 parts by weight is inferior in trauma resistance and flame retardancy, and Comparative Example 6 with a large amount of 350 parts by weight is Although it has good trauma resistance and flame retardancy, it can be seen that the elongation is low at 138%, so that the amount of magnesium hydroxide added to the olefin polymer is in the range of 40 to 300 parts by weight.

Claims (5)

  In a non-halogen flame retardant wire coated with a non-halogen resin composition obtained by adding a flame retardant such as magnesium hydroxide or aluminum hydroxide surface-treated with a silane coupling agent to an olefin polymer, the molecular weight is 200 or more, preferably 240 or more, A non-halogen flame-retardant electric wire / cable characterized by using, as an insulating layer, a resin composition in which a flame retardant surface-treated with a silane coupling agent having a linear molecular structure is mixed with an olefin polymer.   Silane coupling agents are γ-methacryloxypropyltrimethoxysilane, n-hexadecyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-ureidopropyltriethoxysilane, γ-dibutylamino. The non-halogen flame-retardant electric wire / cable according to claim 1, comprising propyltrimethoxysilane, γ-diallylaminopropyltrimethoxysilane, or the like.   The non-halogen flame-retardant electric wire / cable according to claim 1 or 2, wherein 40 to 300 parts by weight of magnesium hydroxide or aluminum hydroxide surface-treated with a silane coupling agent is mixed alone or in combination with 100 parts by weight of an olefin polymer.   The halogen-free flame retardant electric wire / cable according to any one of claims 1 to 3, wherein the particle size of magnesium hydroxide or aluminum hydroxide is 1.5 µm or less, preferably 1.0 µm or less.   The non-halogen flame-retardant electric wire / cable according to any one of claims 1 to 4, wherein 1 to 30 parts by weight of a maleic acid copolymer is used in combination with the olefin polymer.