JP2005200574A - Non-halogen flame-retardant resin composition and electric wire/cable using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-halogen flame-retardant resin composition having high flame retardance without impairing mechanical properties such as elongation and tensile strength by using a high-molecular weight ethylene-vinyl acetate copolymer (EVA) having a high VA content and newly synthesized by multi-step polymerization and an electric wire/cable using the resin composition. <P>SOLUTION: The non-halogen flame-retardant resin composition comprises 100 pts. wt. base polymer composed of an ethylene-vinyl acetate copolymer (EVA) having ≥40 wt% vinyl acetate content and 0.1-1.0 g/10 min MFR or base polymer obtained by mixing the EVA with the other polyolefin-based resin, 150-300 pts. wt. metal hydroxide and 20-50 pts. wt. 1,3,5-triazine derivative. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a halogen-free flame retardant resin composition and an electric wire / cable using the same, and in particular, a halogen-free flame retardant resin composition that does not generate toxic gases such as a halogen-based gas and a phosphine gas during combustion, and a conductor thereof It is related with the electric wire and cable used for the insulator of this.

  Conventionally, as a flame retardant resin composition not containing a halogen compound, a composition obtained by adding a metal hydroxide such as magnesium hydroxide or aluminum hydroxide to a polyolefin-based resin has been used. Since these compositions do not generate toxic gases such as hydrogen chloride or dioxin during combustion, they can prevent the generation of toxic gases in the event of a fire or secondary disasters, and can be incinerated at the time of disposal. It doesn't matter.

  However, there are many cases where the target flame retardancy cannot be obtained simply by adding a metal hydroxide alone. Therefore, a phosphorus-containing flame retardant such as red phosphorus is used as a flame retardant aid for improving flame retardancy. Addition is performed (patent documents 1 to 3).

JP 2002-42574 A JP 2002-42575 A JP 2003-113276 A

  However, when the amount of the metal hydroxide added is increased, there is a problem that mechanical properties such as elongation and tensile strength are remarkably lowered.

  In addition, for the purpose of improving mechanical properties, the base polymer ethylene-vinyl acetate copolymer (EVA) having a high molecular weight has been synthesized so far with only a low amount of vinyl acetate (VA) in the polymer. It was not possible and the flame retardancy was insufficient.

  Accordingly, the object of the present invention is to use a high molecular weight, high VA amount EVA newly synthesized by multi-stage polymerization, without impairing mechanical properties such as elongation and tensile strength, and having high flame resistance. It is providing a flame retardant resin composition and an electric wire and cable using the same.

  In the present invention, an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 40 wt% or more and a melt flow rate (MFR) of 0.1 to 1.0 g / 10 min is used alone or other polyolefin-based resin. A halogen-free flame retardant resin composition comprising 150 to 300 parts by weight of a metal hydroxide and 20 to 50 parts by weight of a 1,3,5-triazine derivative is provided with respect to 100 parts by weight of a base polymer mixed with.

  The base polymer preferably contains 1 to 20 parts by weight of an ethylene copolymer modified with maleic acid or a derivative thereof in the base polymer.

  The metal hydroxide is preferably at least one selected from the group consisting of these metal hydroxides in which magnesium hydroxide, aluminum hydroxide, calcium hydroxide and nickel are dissolved.

  The present invention provides an electric wire / cable using the above halogen-free flame retardant resin composition as a conductor insulator or sheath.

  The non-halogen flame retardant resin composition according to the present invention does not generate harmful gas during combustion, and has high flame retardancy and excellent mechanical strength. Further, by using the resin composition for an insulator or a sheath, it is possible to obtain an electric wire / cable that does not generate harmful gas during use and has high flame retardancy and excellent mechanical strength.

  The non-halogen flame retardant resin composition of the present invention and the electric wire / cable using the non-halogen flame retardant resin composition as a conductor insulator or sheath will be described.

  The ethylene-vinyl acetate copolymer (EVA) used in the present invention has a high molecular weight and a high VA amount newly synthesized by multistage polymerization, has a vinyl acetate content of 40 wt% or more, and has a melt flow rate (MFR). A 0.1-1.0 g / 10min thing is used, and this is used individually or in mixture with other polyolefin resin.

  Here, EVA is used to improve flame retardancy. The EVA has a vinyl acetate content of 40 wt% or more and an MFR of 0.1 to 1.0 g / 10 min because a sufficient flame retardant effect cannot be obtained with a content of less than 40 wt%. In addition, when the polymer has an MFR greater than 1.0 g / 10 min, the characteristics such as the tensile strength are significantly deteriorated. In addition, the measurement of MFR is a value at the time of measuring by 190 degreeC and the load of 2.16 kg based on JISK6924.

  The amount of the ethylene-vinyl acetate copolymer added to the base polymer is preferably 80 parts by weight or more. Other ethylene copolymers and polyolefin resins to be mixed with the ethylene-vinyl acetate copolymer include low density, medium density, and high density polyethylene, linear low density polyethylene, linear ultra-low density polyethylene, Ethylene-methyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-styrene copolymer, ethylene-maleic anhydride copolymer, maleic acid grafted linear low density polyethylene, etc. Is mentioned. These can be used alone or in combination of two or more.

  Examples of the metal hydroxide to be added to the base polymer include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and these metal hydroxides in which nickel is dissolved. These may be used alone or in combination of two or more. These metal hydroxides may be silane coupling agents, titanate coupling agents, fatty acids such as stearates and calcium stearates, or those surface-treated with fatty acid metal salts. Further, an appropriate amount of other metal hydroxide may be added.

  In the present invention, the addition amount of the metal hydroxide is 150 to 300 parts by weight with respect to 100 parts by weight of the base polymer. If the addition amount is less than 150 parts by weight, sufficient flame retardancy cannot be obtained. If the amount is more than part by weight, the mechanical properties are significantly deteriorated.

  Examples of the 1,3,5-triazine derivative added to the base polymer include melamine, cyanuric acid, isocyanuric acid, melamine cyanurate, and melamine sulfate. More preferred is melamine cyanurate. These may be surface-treated with a nonionic surfactant or various coupling agents.

  In the present invention, the 1,3,5-triazine derivative is 20 to 50 parts by weight with respect to 100 parts by weight of the base polymer, and if the addition amount is less than 20 parts by weight, a sufficient flame retardant effect cannot be obtained, If it exceeds 50 parts by weight, the mechanical strength is remarkably lowered.

  Since the 1,3,5-triazine derivative decomposes and sublimates at 300 ° C. or higher during combustion and generates nonflammable gas, it is considered to contribute to flame retardancy.

  Examples of the ethylene copolymer modified with maleic acid or a derivative thereof include maleic acid-modified EEA, maleic acid-modified EVA, maleic acid-modified SEBS, and the like. If the amount added is less than 1 part by weight, the tensile strength characteristics will not be improved, and if it is used more than 20 parts by weight, the elongation characteristics of the entire resin composition will deteriorate.

  In addition to the above ingredients, additives such as antioxidants, lubricants, softeners, plasticizers, inorganic fillers, compatibilizers, stabilizers, carbon black, and colorants can be added as necessary. It is.

  Furthermore, chemical crosslinking with an organic peroxide or irradiation crosslinking with radiation such as an electron beam may be performed.

  Examples of electric wires and cables using the non-halogen resin composition of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram showing an electric wire / cable 12 in which a copper conductor 1 is covered with an insulator 2 and a three-wire core electric wire 11 is twisted together with an intervening 4, a press-wrapping tape 5 is applied, and the outermost layer is extruded and covered. The sheath 3 is made of the non-halogen flame retardant resin composition of the present invention.

  FIG. 2 shows an electric wire 11 in which an insulator 2 is coated on a copper conductor 1, and the insulator 2 is made from the non-halogen flame retardant resin composition of the present invention.

  FIG. 3 shows an insulation core 6 in which a copper conductor 1 is coated with an insulator 2, and an outer layer of a core 8 in which four pairs of twisted wires 7 obtained by twisting the insulation core 6 are twisted together is formed as a sheath inner layer. 9 and the sheath / outer layer 10 are extrusion-coated electric wires / cables 13.

  The sheath inner layer 9 and the sheath outer layer 10 are produced from the non-halogen flame retardant resin composition of the present invention.

  The resin molded product and the electric wire / cable were produced as follows.

  Various components are blended at the blending ratios shown in Table 1, and after kneading with a pressure kneader at a start temperature of 40 ° C. and an end temperature of 190 ° C., the kneaded product is pelletized, and this is used as the insulator 2 of the electric wire 11 shown in FIG. The material was extruded at a set temperature of 230 ° C. with a thickness of 0.41 mm.

  The evaluation of the electric wire was determined by the following method.

(1) Tensile test Tensile test is performed on the prepared electric wire in accordance with JIS C 3005. Elongation is less than 150% x (fail), 150-300% is o (pass), and more Double circle (passed with tolerance).

(2) Flame retardance test The produced electric wire was subjected to a vertical combustion test (VW-1) based on ULsubject758. Judgment made the thing of combustion time less than 1 minute (circle) (pass), and the thing more than 1 minute made x (fail).

  Examples produced using the resin composition of the present invention are shown in Table 1, and Comparative Examples produced in the same manner as described above are shown in Table 2.

  In Examples 1 to 10, the elongation / tensile strength satisfied the target, all the vertical combustion tests passed, and good characteristics were exhibited.

  On the other hand, as shown in Table 2, in Comparative Examples 1 and 4 where the MFR is larger than specified and Comparative Example 6 where the amount of metal hydroxide added is smaller than specified, the tensile strength is insufficient.

  Further, Comparative Example 5 in which the vinyl acetate content of the ethylene-vinyl acetate copolymer is less than specified and Comparative Example 7 in which the amount of 1,3,5-triazine derivative added is less than specified are insufficient in flame retardancy. . In Comparative Example 6 in which the addition amount of the metal hydroxide was more than specified and Comparative Example 8 in which the addition amount of the 1,3,5-triazine derivative was more than specified, the elongation characteristics were insufficient.

It is a figure which shows the cable which coat | covered the outer periphery of three insulated wire cores with a press-wound tape and a sheath to which this invention is applied. It is a figure which shows the electric wire which coat | covered with the insulator on the copper conductor to which this invention is applied. It is a figure which shows the cable which coat | covered the outer periphery of the core of four pairs of twisted wires with a double sheath layer to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copper conductor 2 Insulator 3 Sheath 4 Interposition 5 Pressing winding tape 6 Insulated wire core 7 Paired twisted wire 8 Core 9 Sheath inner layer 10 Sheath outer layer 11 Electric wire 12, 13 Electric wire and cable

Claims (4)

  A base in which an ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 40 wt% or more and a melt flow rate (MFR) of 0.1 to 1.0 g / 10 min is used alone or mixed with other polyolefin resins. A non-halogen flame retardant resin composition comprising 150 to 300 parts by weight of a metal hydroxide and 20 to 50 parts by weight of a 1,3,5-triazine derivative with respect to 100 parts by weight of a polymer.   The non-halogen flame retardant resin composition according to claim 1, comprising 1 to 20 parts by weight of an ethylene copolymer modified with maleic acid or a derivative thereof in the base polymer.   3. The non-halogen according to claim 1, wherein the metal hydroxide is at least one selected from the group consisting of these metal hydroxides in which magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and nickel are dissolved. Flame retardant resin composition. An electric wire / cable comprising the non-halogen flame retardant resin composition according to any one of claims 1 to 3 used as a conductor insulator or sheath.

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