JP2011046786A - Flame-retardant resin composition, insulation wire and cable using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant resin composition or the like having both of excellent mechanical characteristics and flame retardancy. <P>SOLUTION: The flame-retardant resin composition contains a base resin comprising two or more kinds of polyolefin-based resins, metal hydroxide particles, inorganic oxide particles containing silicon atoms, and gummy silicone compound, regulated so that the proportion of the metal hydroxide particles may be ≤150 pts.mass based on 100 pts.mass of the base resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a flame retardant resin composition, an insulated wire and a cable using the same.

  Polyvinyl chloride compositions are widely used in wire coatings, tubes, tapes, packaging materials, building materials, etc. because of their good electrical insulation and excellent flame retardancy and mechanical properties. Lead-free polyvinyl chloride resin that does not use lead as a stabilizer is becoming mainstream because of concerns about the effects on the human body.

  The lead-free polyvinyl chloride resin contains chlorine atoms in its molecular structure, and generates toxic and harmful chlorine gas during combustion. Therefore, a vinyl chloride electric wire replacement using a so-called eco-material with higher safety is being studied.

  As such an eco-material, a flame retardant composed of metal hydroxide particles such as magnesium hydroxide and aluminum hydroxide, and a flame retardant assistant composed of silicone compounds such as gum silicone oil, based on polyolefin resin. Additives are known (see Patent Document 1 below).

JP 2000-248126 A

  However, the flame retardant resin composition described in Patent Document 1 still has room for improvement, particularly in terms of flame retardancy.

  The present invention has been made in view of the above circumstances, and provides a flame retardant resin composition capable of achieving both excellent mechanical properties and flame retardancy, and an insulated wire and cable using the same. Objective.

  The present inventor thought that the cause of the above problems may be that the affinity between the polyolefin resin and the gum-like silicone compound is not good and the dispersibility is insufficient. Here, in order to improve the dispersibility of the gum silicone compound, a master batch is prepared by kneading the gum silicone compound with the same resin as the base resin. It is considered that kneading with the oxide particles is sufficient. However, even in this case, if the base resin is composed of a blend of two or more resins, the dispersibility of the gum-like silicone compound cannot be sufficiently improved, and there is still room for improvement in terms of flame retardancy. It was. Therefore, as a result of intensive research to further improve the flame retardancy, the present inventor has used not only gum-like silicone compounds in the flame retardant resin composition but generally imparts slipperiness. It was found that the flame retardancy was sufficiently improved by including inorganic oxide particles containing silicon atoms such as silica, and the present invention was completed.

  That is, the present invention includes a base resin composed of two or more polyolefin-based resins, metal hydroxide particles, inorganic oxide particles containing silicon atoms, and a gum-like silicone compound, wherein the metal hydroxide particles are The flame retardant resin composition is blended at a ratio of 150 parts by mass or less with respect to 100 parts by mass of the base resin.

  According to the flame retardant resin composition of the present invention, both excellent mechanical properties and flame retardancy can be achieved.

  In addition, this inventor has guessed as follows about the reason why the flame retardance more excellent in the flame-retardant resin composition of this invention is acquired.

  That is, it is presumed that excellent flame retardancy was obtained by the char formation promoting action starting from the inorganic oxide and the high dispersion of the silicone compound.

  Moreover, this invention is an insulated wire provided with the conductor and the insulating layer which coat | covers the said conductor, and the said insulating layer is comprised with the said flame-retardant resin composition. The insulating layer may be formed by crosslinking the flame retardant resin composition.

  The present invention further includes an insulated wire having a conductor and an insulating layer covering the conductor, and a sheath covering the insulated wire, wherein at least one of the insulating layer and the sheath is composed of the flame retardant resin composition. Cable may be used. In addition, at least one of the insulating layer and the sheath may be formed by crosslinking the flame retardant resin composition.

  Furthermore, the present invention includes a kneading step of kneading a base resin composed of two or more polyolefin-based resins, metal oxide particles, inorganic oxide particles containing silicon atoms, and a gum-like silicone compound, The method for producing a flame retardant resin composition, wherein the oxide particles are blended at a ratio of 150 parts by mass or less with respect to 100 parts by mass of the base resin.

  According to this method for producing a flame-retardant resin composition, the gum-like silicone compound and the inorganic oxide particles containing silicon atoms are kneaded together with the base resin, so that the dispersibility of the gum-like silicone compound is sufficient. Thus, it is possible to improve the flame retardancy. For this reason, the flame-retardant resin composition which can make the outstanding mechanical characteristic and flame retardance compatible can be obtained.

  The present invention also provides a flame retardant resin composition preparing step for preparing a flame retardant resin composition, and forming an insulating layer by covering a conductor with the flame retardant resin composition to obtain an insulated wire. A method for producing an insulated wire, comprising the steps of: producing the flame retardant resin composition by the method for producing a flame retardant resin composition described above.

  According to this method for producing an insulated wire, since the flame retardant resin composition is produced by the method described above, an insulated wire capable of achieving both excellent mechanical properties and flame retardancy can be obtained.

  The present invention also provides a method for producing a sheath, comprising: a flame retardant resin composition preparing step for preparing a flame retardant resin composition; and a sheath forming step for obtaining a sheath by extruding the flame retardant resin composition. And it is the manufacturing method of the sheath characterized by manufacturing the said flame-retardant resin composition with the manufacturing method of the flame-retardant resin composition mentioned above.

  According to this sheath manufacturing method, since the flame retardant resin composition is manufactured by the above-described method, a sheath capable of achieving both excellent mechanical properties and flame retardancy can be obtained.

  Furthermore, the present invention includes an electric wire manufacturing process for manufacturing an insulated wire by covering an inner conductor with an insulating layer, and a sheath covering step for covering the insulated wire with a sheath to obtain a cable. It is a manufacturing method of the cable characterized by manufacturing with the manufacturing method of an insulated wire. The present invention also relates to a cable manufacturing method comprising: an electric wire manufacturing process for manufacturing an insulated wire by covering an inner conductor with an insulating layer; and a sheath coating process for obtaining a cable by covering a sheath surrounding the insulated wire with a sheath. The cable manufacturing method is characterized in that the sheath is manufactured by the above-described sheath manufacturing method.

  According to these cable manufacturing methods, since the flame-retardant resin composition or the sheath is manufactured by the above-described method, a cable capable of achieving both excellent mechanical properties and flame retardancy can be obtained.

  The metal hydroxide particles are preferably blended at a ratio of 5 parts by mass or more with respect to 100 parts by mass of the base resin. In this case, the flame retardancy of the flame retardant resin composition can be further improved.

  The inorganic oxide particles and the gum-like silicone compound are preferably blended in a ratio of 1 to 30 parts by mass with respect to 100 parts by mass of the base resin. In this case, more excellent flame retardancy is easily obtained as compared with the case where the blending ratio of the inorganic oxide particles and the gum-like silicone compound is out of the above range.

  The blending ratio of the inorganic oxide particles in the inorganic oxide particles and the gum-like silicone compound is preferably 20 to 45% by mass. In this case, the flame retardance more excellent than the case where the compounding rate of the said inorganic oxide particle and the said inorganic oxide particle in a gum-like silicone type compound remove | deviates from the said range becomes easy to be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the flame retardant resin composition which can make the outstanding mechanical characteristic and flame retardance compatible, and an insulated wire and a cable using the same are provided.

It is a partial side view which shows one Embodiment of the cable of this invention. It is sectional drawing along the II-II line of FIG.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

[cable]
FIG. 1 is a partial side view showing an embodiment of a cable according to the present invention, and shows a flat cable for indoor wiring. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. As shown in FIG. 1, the flat cable 10 includes an insulated wire 4 and a sheath 3 that covers the insulated wire 4. The insulated wire 4 includes an inner conductor 1 and an insulating layer 2 that covers the inner conductor 1.

  Here, the insulating layer 2 is made of a flame retardant resin composition, and the flame retardant resin composition is an inorganic material containing a base resin made of two or more polyolefin resins, metal hydroxide particles, and silicon atoms. It contains oxide particles and a gummy silicone compound. Here, the metal oxide particles are blended at a ratio of 150 parts by mass or less with respect to 100 parts by mass of the base resin.

  According to the cable 10 having such a configuration, it is possible to achieve both excellent mechanical properties and flame retardancy.

  In the flame-retardant resin composition, it is preferable that at least a part of the inorganic oxide particles are embedded in the gum-like silicone compound. In this case, char formation tends to be promoted.

[Cable manufacturing method]
Next, the manufacturing method of the flat cable 10 mentioned above is demonstrated.

<Preparation process of flame retardant resin composition>
First, the flame retardant resin composition is prepared. The flame-retardant resin composition comprises a base resin composed of two or more polyolefin resins, metal oxide particles, and composite particles in which inorganic oxide particles containing silicon atoms are embedded in a gum-like silicone compound. It can be obtained by kneading. Hereinafter, each of the base resin, the metal oxide particles, and the composite particles will be described in detail.

(Base resin)
As described above, the base resin contains two or more polyolefin resins. Examples of such two or more polyolefin resins include polyethylene such as high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and low-density polyethylene (LDPE); ethylene-α olefin copolymer; ethylene Ethylene-acrylate copolymers such as ethyl acrylate (EEA), ethylene butyl acrylate (EBA), ethylene methyl acrylate (EMA), ethylene methyl methacrylate (EMMA); ethylene-vinyl acetate copolymer (EVA); ethylene propylene rubber (EPR), ethylene diene rubber (EPDM); acid-modified polyolefin; use two or more polyolefin resins selected from polypropylene such as isotactic polypropylene and atactic polypropylene. It can be. Among them, it is preferable to use two or more polyolefin resins selected from EEA, EMA, EMMA, EVA since they can exhibit excellent flame retardancy together with a gum-like silicone compound, and more preferably from EVA and EEA. It is more preferable to use a mixed resin. Here, the blending ratio of EVA in the mixed resin is preferably 50% by mass or less from the viewpoint of improving flame retardancy. Moreover, as EEA used with EVA, that whose MFR measured by 190 degreeC and load 2.16kg is 0.5 (g / 10min) or less is preferable from the point of a flame retardance improvement.

(Metal hydroxide particles)
The metal hydroxide particles are composed of metal hydroxide. Examples of the metal hydroxide include magnesium hydroxide, calcium hydroxide, and aluminum hydroxide. Among these, magnesium hydroxide is preferable. This is because the extrudability and flame retardancy when coating the inner conductor 1 can be improved.

  The metal hydroxide particles are included at a ratio of 150 parts by mass or less with respect to 100 parts by mass of the base resin, and preferably included at a ratio of 5 to 100 parts by mass, and a ratio of 5 to 80 parts by mass. It is more preferable that it is contained. When the ratio of the metal hydroxide particles exceeds 150 parts by mass, the mechanical properties are deteriorated. When the ratio of the metal hydroxide particles is less than 5 parts by mass, the flame retardancy is reduced as compared with the case of 5 parts by mass or more. From the viewpoint of recyclability, the amount of metal hydroxide added is preferably about 50 parts by mass or less. By making the addition amount of the metal hydroxide about 50 parts by mass or less, the specific gravity of the resin composition becomes about 1.15 or less, cross-linked polyethylene (specific gravity 0.9), polyvinyl chloride (specific gravity about 1.4) It becomes possible to separate the specific gravity from the conventional ecomaterial (specific gravity about 1.4).

(Composite particles)
The composite particles are obtained by embedding inorganic oxide particles containing silicon atoms in a gum-like silicone compound. By kneading such composite particles together with the base resin and metal hydroxide particles, the dispersibility of the gum-like silicone compound in the base resin can be sufficiently improved.

  The gum-like silicone compound refers to a polyorganosiloxane that functions as a flame retardant aid, has a particularly high viscosity among silicone oils, and has a number average molecular weight of about 100,000 to 1,000,000. The polyorganosiloxane has a siloxane bond as a main chain and an organic group in a side chain. Examples of the organic group include a methyl group, a vinyl group, an ethyl group, a propyl group, and a phenyl group. Specifically, as the polyorganosiloxane, for example, dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, methyl (3,3,3-trifluoropropyl) polysiloxane, etc. Is mentioned.

The inorganic oxide particles need only be inorganic oxide particles containing silicon (Si) atoms, and are inorganic composite oxide particles containing aluminum (Al) atoms and magnesium (Mg) atoms in addition to Si atoms. Also good. Examples of such inorganic oxide particles include SiO ₂ , SiO, aluminosilicate, MgSiO ₃ , and the like. Among these, SiO ₂ is preferable from the viewpoint of compatibility with silicone gum.

  In the flame-retardant resin composition, the composite particles are preferably kneaded together with the base resin and the metal hydroxide particles in a total ratio of 1 to 30 parts by mass with respect to 100 parts by mass of the base resin. In this case, more excellent flame retardancy is easily obtained as compared with the case where the compounding ratio of the composite particles is out of the above range.

  The compounding ratio of the inorganic oxide particles in the composite particles is preferably 20 to 45% by mass, more preferably 30 to 40% by mass. In this case, more excellent flame retardancy is easily obtained as compared with the case where the compounding ratio of the inorganic oxide particles in the composite particles is out of the above range.

  The flame retardant resin composition may contain a filler such as an antioxidant, an ultraviolet degradation inhibitor, a processing aid, a color pigment, a lubricant, carbon black, and a crosslinking aid as necessary.

  The base resin, metal hydroxide particles, composite particles, and the like can be kneaded with a kneader such as a Banbury mixer, tumbler, pressure kneader, kneading extruder, twin screw extruder, or mixing roll.

  During kneading, the metal hydroxide particles may be previously surface treated with a gum-like silicone compound or fatty acid similar to the gum-like silicone compound constituting the composite particles. In this case, it is preferable that the entire metal hydroxide particles contained in the flame-retardant resin composition are coated with a gum-like silicone compound or a fatty acid.

As a method for attaching the gum-like silicone compound or fatty acid to the surface of the metal hydroxide particles, for example, the gum-like silicone compound or fatty acid is added to the metal hydroxide particles and mixed to obtain a mixture. The mixture can be obtained by drying at 40 to 75 ° C. for 10 to 40 minutes, and pulverizing the dried mixture with a Henschel mixer, an atomizer or the like.
The silicone compound may be added at the time of kneading without adhering to the surface of the metal hydroxide particles in advance.

<Insulating layer formation process>
Next, the inner conductor 1 is covered with the flame retardant resin composition. Specifically, the flame retardant resin composition is melt kneaded using an extruder to form a tubular extrudate. Then, the tubular extrudate is continuously coated on the inner conductor 1. Thus, an insulated wire 4 in which the inner conductor 1 is covered with the insulating layer 2 is obtained. Note that the inner conductor 1 may be configured by only one strand or may be configured by bundling a plurality of strands. Further, the inner conductor 1 is not particularly limited with respect to the conductor diameter, the material of the conductor, and the like, and can be appropriately determined according to the application.

<Sheath coating process>
Finally, two insulated wires 4 obtained as described above are prepared, and these insulated wires 4 are covered with the flame retardant resin composition to form a sheath 3 (sheath forming step). The sheath 3 protects the insulating layer from physical or chemical damage. The flat cable 10 which coat | covered the insulated wire 4 with the sheath 3 as mentioned above is obtained.

  According to the manufacturing method of the flat cable 10 described above, excellent mechanical characteristics and flame retardancy can be achieved in the flat cable 10 to be obtained.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the flat cable 10 has two insulated wires 4, but the flat cable 10 may have only one insulated wire 4, or may have three or more wires. Good.

  Moreover, in the said embodiment, although the insulating layer 2 and the sheath 4 of the insulated wire 4 are comprised with said flame-retardant resin composition, the insulating layer 2 is comprised with normal insulating resin, and only the sheath 3 is an insulating layer. 2 may be comprised of a flame retardant resin composition.

  Furthermore, in the above embodiment, during kneading, the inorganic oxide particles and the gum-like silicone compound are added in the state of composite particles, that is, the inorganic oxide particles are embedded in the gum-like silicone compound. The oxide particles and gum-like silicone compound do not necessarily need to be added in the form of composite particles. That is, the inorganic oxide particles and the gum silicone compound may be added separately during kneading.

  Hereinafter, the content of the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples.

(Examples 1-11 and Comparative Examples 1-5)
EVA, EEA1, EEA2, EEA3, surface-treated magnesium hydroxide (hereinafter referred to as “magnesium hydroxide” is referred to as “Mg hydroxide”) 1, surface-treated magnesium hydroxide 2, silicone gum master batch, silica-containing silicone gum 1, silica The contained silicone gum 2 and the silica-containing silicone gum 3 were blended at the blending ratios shown in Tables 1 to 3, and kneaded with a Banbury mixer to obtain a flame retardant resin composition. In Tables 1 to 3, the unit of the blending amount of each blending component is part by mass.

Specific examples of the EVA, EEA1, EEA2, EEA3, surface-treated hydroxide Mg1, surface-treated hydroxide Mg2, silicone gum masterbatch, silica-containing silicone gum 1, silica-containing silicone gum 2, and silica-containing silicone gum 3 are as follows. (1) to (10) were used.
(1) EVA
EV460 (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.)
(2) EEA1
Elvalloy 2116AC (trade name, MFR: 0.3 g / 10 min, manufactured by DuPont)
(3) EEA2
ZE708 (trade name, MFR: 0.5 g / 10 min, manufactured by Ube Maruzen Polyethylene)
(4) EEA3
Elvalloy 2116AC (trade name, MFR: 0.9 g / 10 min, manufactured by DuPont)
(5) Surface-treated hydroxide Mg1
X-22-1894A (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
(6) Surface-treated hydroxide hydroxide Mg2
Kisuma 5A (trade name, manufactured by Kyowa Chemical Co., Ltd.)
(7) Silicone gum masterbatch X-22-2138B (trade name, EVA460 and polyorganosiloxane (X-21-3043) kneaded at 60:40 (mass ratio) to form a masterbatch, Shin-Etsu Chemical Co., Ltd. (Made by company)
(8) Silica-containing silicone gum 1
GENIOPLAST PELLET S (trade name, silica: 35% by mass, polyorganosiloxane content: 65%, manufactured by Wacker Chemie Co., Ltd.)
(9) Silica-containing silicone gum 2
Composite particles in which silica is embedded in polyorganosiloxane (silica: 20% by mass, polyorganosiloxane content: 80% content)
(10) Silica-containing silicone gum 3
Composite particles in which silica is embedded in polyorganosiloxane (silica: 45% by mass, polyorganosiloxane content: 55%)

  Kisuma 5A is obtained by surface-treating about 3% of Mg hydroxide with fatty acid. Here, 3% surface treatment means that the content of fatty acid in the surface-treated hydroxide Mg2 is 3%. X-22-1894A is a surface treated MgO2 surface treated with polyorganosiloxane (X-21-3043) for about 6%. Here, 6% surface treatment means that the content of polyorganosiloxane in the surface-treated hydroxide Mg1 is 6%.

Next, this flame retardant resin composition was kneaded at 160 ° C. for 15 minutes by a Banbury mixer. Thereafter, the flame retardant resin composition was put into a single screw extruder (L / D = 20, screw shape: full flight screw, manufactured by Mars Seiki Co., Ltd.), and the cylinder in the crosshead was discharged from the discharge port of the extruder. A flame-retardant resin composition is injected into the cylindrical space, and a tube-shaped extrudate is extruded from the cylindrical space to a thickness of 0.8 mm on the conductor (number of strands 7 / strand diameter 0.6 mm). Was coated as follows. Thus, an insulated wire having an outer diameter of 3.4 mm was obtained.

  About the insulated wires of Examples 1 to 11 and Comparative Examples 1 to 5 obtained as described above, mechanical properties and flame retardancy were evaluated as follows.

(Mechanical properties)
The mechanical properties were evaluated by performing a tensile test on the insulated wires of Examples 1 to 11 and Comparative Examples 1 to 5 according to JIS standard C3005. At this time, the tensile speed was 200 mm / min, and the distance between the marked lines was 20 mm. And those having a tensile strength of 10 MPa or more were accepted and those less than 10 MPa were rejected. The results are shown in Tables 1 to 3. In Tables 1 to 3, the acceptable insulated wires are indicated by “◯”, and the rejected insulated wires are indicated by “x”.

(Flame retardance)
About the insulated wire of Examples 1-11 and Comparative Examples 1-5, the oxygen index was measured according to the test method of JISK7201. The results are shown in Tables 1-3.

  From the results shown in Tables 1 to 3, it can be seen that the insulated wires of Examples 1 to 11 can achieve both excellent mechanical properties and flame retardancy as compared with the insulated wires of Comparative Examples 1 to 5. It was.

  From this, it was confirmed that according to the flame-retardant resin composition of the present invention, both excellent mechanical properties and flame retardancy can be achieved.

DESCRIPTION OF SYMBOLS 1 ... Internal conductor, 2 ... Insulating layer, 3 ... Outer conductor, 4 ... Sheath, 5 ... Insulated electric wire, 10 ... Flat cable.

Claims (7)

A base resin composed of two or more polyolefin resins;
Metal hydroxide particles,
Inorganic oxide particles containing silicon atoms;
A gummy silicone compound;
Including
The flame retardant resin composition, wherein the metal hydroxide particles are blended at a ratio of 150 parts by mass or less with respect to 100 parts by mass of the base resin.   The flame-retardant resin composition according to claim 1, wherein the metal hydroxide particles are blended at a ratio of 5 parts by mass or more with respect to 100 parts by mass of the base resin.   The flame-retardant resin composition according to claim 1 or 2, wherein the inorganic oxide particles and the gum-like silicone compound are blended in a proportion of 1 to 30 parts by mass in total with respect to 100 parts by mass of the base resin. object.   The flame-retardant resin composition according to any one of claims 1 to 3, wherein a blending ratio of the inorganic oxide particles and the inorganic oxide particles in the gum-like silicone compound is 20 to 45 mass%. Conductors,
An insulating layer covering the conductor;
With
The insulating layer is composed of the flame retardant resin composition according to any one of claims 1 to 4,
Insulated wire characterized by Conductors,
An insulating layer covering the conductor;
With
The insulating layer is formed by crosslinking the flame retardant resin composition according to any one of claims 1 to 4.
Insulated wire characterized by An insulated wire having an inner conductor and an insulating layer covering the inner conductor;
A sheath for covering the insulated wire,
At least one of the insulating layer and the sheath is composed of the flame retardant resin composition according to any one of claims 1 to 4, or the flame retardancy according to any one of claims 1 to 4. A cable obtained by crosslinking a resin composition.

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