JP5993264B2 - Method for producing flame retardant resin composition, flame retardant resin composition and cable using the same - Google Patents

Description

  The present invention relates to a method for producing a flame retardant resin composition, a flame retardant resin composition, and a cable using the same.

  Flame retardant resin compositions are widely used in wire coatings, tubes, tapes, packaging materials, building materials, and the like.

  As a method for producing such a flame retardant resin composition, the following Patent Document 1 discloses that a polyolefin-based resin, a metal hydroxide surface-treated with ammonium molybdate, and a magnesium hydroxide surface-treated with a hydrophobic compound are disclosed. And the manufacturing method of the flame retardant resin composition including the process of mix | blending a silicone type compound is disclosed, By this manufacturing method, the flame retardant resin composition which has the outstanding flame retardance and mechanical characteristics is disclosed. It is disclosed that it can be obtained.

JP 2001-110236 A

  By the way, since the molded article using the flame retardant resin composition is often used in an environment that comes into contact with water, such as outdoors, the flame retardant resin composition has flame resistance and mechanical properties. In addition to being excellent, it is required to be further excellent in water resistance.

  However, the flame-retardant resin composition produced by the production method described in Patent Document 1 has room for further improvement in terms of water resistance.

  For this reason, the manufacturing method of the flame-retardant resin composition which has the outstanding water resistance, ensuring the outstanding mechanical characteristic and the outstanding flame retardance was calculated | required.

  The present invention has been made in view of the above circumstances, and a method for producing a flame retardant resin composition having excellent water resistance while ensuring excellent mechanical properties and excellent flame retardancy, and flame retardant An object of the present invention is to provide a conductive resin composition and a cable using the same.

  In order to solve the above-mentioned problems, the present inventors have studied paying attention to the type and blending method of the molybdate compound blended in the polyolefin-based resin. As a result, when the powder of the divalent metal salt of molybdic acid is directly blended with the polyolefin resin, the water resistance of the resin composition is higher than when ammonium molybdate supported on the metal hydroxide is blended with the polyolefin resin. It became clear that the property was remarkably improved. Therefore, as a result of further diligent research, the present inventors have conducted studies on magnesium hydroxide particles that have been surface-treated with a silicone compound and a hydrophobic compound at a specific ratio with respect to the polyolefin resin, and the divalent molybdenum oxide. By directly blending a metal salt, it was found that a flame-retardant resin composition having excellent water resistance can be produced while ensuring excellent mechanical properties and excellent flame retardancy, and the present invention It came to be completed.

  That is, the present invention includes a step of blending the silicone compound (B) at a ratio of 3 to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin (A), and 100 parts by mass of the polyolefin resin (A). The step of blending the surface-treated magnesium hydroxide particles (C) obtained by surface-treating the magnesium hydroxide particles with a hydrophobic compound at a ratio of 50 to 150 parts by mass, and 100 parts by mass of the polyolefin resin (A) In contrast, a flame retardant resin composition comprising at least a step of blending the molybdate compound (D) at a ratio of 5 to 20 parts by mass, wherein the molybdate compound (D) is a divalent metal salt of molybdate. It is a manufacturing method.

  According to the method for producing a flame retardant resin composition of the present invention, it is possible to produce a flame retardant resin composition having excellent water resistance while ensuring excellent mechanical properties and excellent flame resistance. it can.

  In addition, the present inventors speculate as follows why the flame retardant resin composition having excellent flame retardancy is produced by the method for producing a flame retardant resin composition of the present invention. .

That is, by including the step of blending the silicone compound (B) with the polyolefin resin (A), when the flame retardant resin composition burns, the silicone compound changes to silica (SiO ₂ ) and burns. Covering the surface of the object, it forms a hard shell (char) and blocks oxygen, preventing the expansion of combustion. Moreover, by including the step of blending the surface-treated magnesium hydroxide particles (C), when the flame retardant resin composition burns, an endothermic reaction occurs in which magnesium hydroxide is decomposed into an oxide and water vapor during combustion. The temperature is lowered, the supply of oxygen to the burning part is hindered by the generated water vapor, the generated oxide adheres to the burning part, and the spread of fire to a new part is hindered. Furthermore, by including the step of blending the molybdate compound (D), when the flame retardant resin composition burns, the molybdate compound (D) carbonizes the polyolefin-based resin at the time of combustion and hard shell (char) This char acts as a heat insulating layer during combustion and inhibits the expansion of combustion. The present inventors speculate that a flame retardant resin composition having excellent flame retardancy is produced by the above-described method by the method for producing a flame retardant resin composition of the present invention.

  Moreover, the present inventors speculate as follows about the reason why the flame-retardant resin composition having excellent water resistance is produced by the method for producing a flame-retardant resin composition of the present invention.

  That is, since the divalent metal salt of molybdic acid has lower solubility in water than the ammonium salt, and also has good dispersion in a polyolefin resin, the method for producing the flame-retardant resin composition of the present invention. Therefore, it is presumed that a flame-retardant resin composition having excellent water resistance is produced.

  In the method for producing the flame retardant resin composition, the hydrophobic compound is preferably a fatty acid-containing compound.

  In this case, a flame retardant resin composition having more excellent water resistance can be produced.

  In the method for producing the flame retardant resin composition, the divalent metal salt of molybdic acid is preferably at least one divalent metal salt selected from the group consisting of calcium zinc molybdate and zinc molybdate.

  In this case, a flame retardant resin composition that is particularly excellent in water resistance can be produced.

  In the manufacturing method of the said flame-retardant resin composition, the process of mix | blending antioxidant (E) in the ratio of 0.01-10 mass parts is further provided with respect to 100 mass parts of said polyolefin resin (A). It is preferable.

  In this case, since the thermal deterioration of the polyolefin resin (A) is sufficiently suppressed, a flame retardant resin composition having excellent heat aging resistance can be produced.

  Moreover, this invention is a flame retardant resin composition manufactured with the manufacturing method of the flame retardant resin composition mentioned above.

  According to the flame-retardant resin composition of the present invention, it is possible to have excellent water resistance while ensuring excellent mechanical properties and excellent flame retardancy.

  Moreover, this invention is equipped with the insulated wire which has a conductor and the insulating layer which coat | covers the said conductor, and the said insulating layer is a cable comprised with the flame-retardant resin composition mentioned above.

  According to the cable of the present invention, since the insulating layer is composed of the above-described flame retardant resin composition, it has excellent water resistance while ensuring excellent mechanical properties and excellent flame resistance. Can do.

  Furthermore, the present invention is a cable having a conductor, an insulating layer covering the conductor, and a sheath covering the insulating layer, wherein at least one of the insulating layer and the sheath is the flame retardant resin composition described above. It is a configured cable.

  According to the cable of the present invention, since at least one of the insulating layer and the sheath is composed of the above-mentioned flame retardant resin composition, it has excellent water resistance while ensuring excellent mechanical properties and excellent flame resistance. Can also have sex.

  According to the present invention, a method for producing a flame retardant resin composition having excellent water resistance while ensuring excellent mechanical properties and excellent flame retardancy, a flame retardant resin composition, and the same are used. A cable is 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, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

[cable]
FIG. 1 is a partial side view showing an embodiment of a cable according to the present invention, and shows a flat cable. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. As shown in FIGS. 1 and 2, the flat cable 10 includes two insulated wires 4 and a sheath 3 that covers the two insulated wires 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 and the sheath 3 are composed of a flame retardant resin composition, and the flame retardant resin composition is composed of a silicone compound (B) with respect to 100 parts by mass of the polyolefin resin (A). 3 to 15 parts by weight, 50 to 150 parts by weight of surface-treated magnesium hydroxide particles (C) obtained by surface-treating magnesium hydroxide particles with a hydrophobic compound, and 5 molybdate compound (D) by itself. It is obtained by blending at a ratio of ˜20 parts by mass. Here, the molybdate compound (D) is a divalent metal salt of molybdate.

  The insulating layer 2 and the sheath 3 made of the flame retardant resin composition have excellent water resistance while ensuring excellent mechanical properties and excellent flame retardancy. For this reason, the flat cable 10 also has excellent water resistance while ensuring excellent mechanical properties and excellent flame retardancy.

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

(conductor)
First, the inner conductor 1 is prepared. The inner conductor 1 may be composed of 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.

(Flame retardant resin composition)
On the other hand, a flame retardant resin composition is prepared. As described above, the flame retardant resin composition has a surface area of 3 to 15 parts by mass of the silicone compound (B) and magnesium hydroxide particles with a hydrophobic compound with respect to 100 parts by mass of the polyolefin resin (A). It is obtained by blending 50 to 150 parts by mass of the surface-treated magnesium hydroxide particles (C) obtained by treatment and 5 to 20 parts by mass of the molybdate compound (D) by itself. Hereinafter, each of the polyolefin resin (A), the silicone compound (B), the surface-treated magnesium hydroxide particles (C), and the molybdate compound (D) will be described in detail.

(A) Polyolefin resin Examples of the polyolefin resin include polyethylene (PE), polypropylene, ethylene-propylene rubber, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl methacrylate copolymer. Examples thereof include a copolymer, an ethylene-ethyl methacrylate copolymer, and an ethylene-vinyl acetate copolymer (EVA). These can be used alone or in combination of two or more. In these, the mixed resin which mixed EEA and EVA is preferable. When a mixed resin of EEA and EVA is used, it is preferable that EVA is contained in a ratio of 5 to 40 parts by mass with respect to 100 parts by mass in total of EEA and EVA.

(B) Silicone compound The silicone compound is not particularly limited, and examples of the silicone compound include polyorganosiloxane. Here, 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. Specific examples of the polyorganosiloxane include dimethylpolysiloxane, methylethylpolysiloxane, methyloctylpolysiloxane, methylvinylpolysiloxane, methylphenylpolysiloxane, and methyl (3,3,3-trifluoropropyl) polysiloxane. Can be mentioned. These can be used alone or in combination of two or more. Examples of the polyorganosiloxane include silicone powder, silicone gum, and silicone resin. Among these, silicone gum is preferable. In this case, bloom is less likely to occur.

  As described above, the silicone compound (B) is blended at a ratio of 3 to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). When the compounding ratio of the silicone compound (B) is less than 3 parts by mass, the flame retardant resin composition cannot have sufficient flame retardancy. On the other hand, when the blending ratio is larger than 15 parts by mass, the mechanical properties are lowered and bloom is likely to occur. The blending ratio of the silicone compound (B) is preferably 3 to 10 parts by mass, more preferably 3 to 7 parts by mass, and particularly preferably 3 to 5 parts by mass.

(C) Surface-treated magnesium hydroxide particles The surface-treated magnesium hydroxide particles (C) are obtained by surface-treating magnesium hydroxide particles with a hydrophobic compound. In the present invention, the hydrophobic compound is a compound having an unsubstituted or fluorine-substituted saturated or unsaturated aliphatic hydrocarbon group and a portion having a binding property to the surface of magnesium hydroxide particles. When the magnesium hydroxide particles are surface-treated with the hydrophobic compound, the surface of the magnesium hydroxide particles becomes hydrophobic, and further, the compatibility of the magnesium hydroxide particles with the polyolefin resin becomes excellent. . Here, as the site having a binding property to the surface of the magnesium hydroxide particle, that is, the site having reactivity with the hydroxyl group of magnesium hydroxide, for example, carboxyl group, carboxylate group, ester group, silane coupling site, titanate A coupling site | part etc. are mentioned. The said hydrophobic compound can be used individually or in combination of 2 or more types. Among these hydrophobic compounds, fatty acid-containing compounds such as unsubstituted saturated or unsaturated fatty acids, alkali metal salts of the fatty acids or esters of the fatty acids impart sufficient water resistance to the flame retardant resin composition. Since it is a compound that can be easily obtained industrially, it is particularly preferably used. The fatty acid contained in the fatty acid-containing compound is preferably a saturated or unsaturated higher fatty acid having 12 or more carbon atoms. Examples of such higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, behenic acid, and montanic acid. The content rate (surface treatment amount) of the hydrophobic compound in the said surface treatment magnesium hydroxide particle (C) should just be 0.1-5 mass%, for example. The BET specific surface area of the magnesium hydroxide particles may be, for example, 1 to ²⁰ m ² / g, and the average particle size is preferably 0.5 to 2.0 μm, more preferably 0.7 to 1.5 μm. .

  As described above, the surface-treated magnesium hydroxide particles (C) are blended at a ratio of 50 to 150 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). When the compounding ratio of the surface-treated magnesium hydroxide particles (C) is less than 50 parts by mass, the flame retardant resin composition cannot have sufficient flame retardancy. On the other hand, when the blending ratio is larger than 150 parts by mass, the mechanical properties are lowered and bloom is likely to occur. The blending ratio of the surface-treated magnesium hydroxide particles (C) is preferably 50 to 120 parts by mass, and more preferably 50 to 100 parts by mass.

(D) Molybdate Compound A divalent metal salt of molybdate is used as the molybdate compound (D). Examples of the divalent metal salt of molybdic acid include zinc molybdate, calcium molybdate, barium molybdate, and calcium zinc molybdate. These can be used alone or in combination of two or more. Ammonium salts such as ammonium molybdate and monovalent metal salts such as sodium molybdate and potassium molybdate are soluble in water, whereas the divalent metal salt of molybdic acid is insoluble in water. By using the divalent metal salt of molybdic acid as the compound (D), excellent water resistance can be imparted to the flame retardant resin composition. Among the divalent metal salts of molybdic acid, calcium zinc molybdate and zinc molybdate are particularly preferably used because they can impart particularly excellent water resistance to the flame-retardant resin composition. The average particle diameter of the molybdate compound is preferably 0.5 to 10 μm, more preferably 0.7 to 5.0 μm.

  As described above, the molybdate compound (D) is blended at a ratio of 5 to 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). When the blending ratio of the molybdate compound (D) is less than 5 parts by mass, the flame retardant resin composition cannot have sufficient flame retardancy. On the other hand, when the blending ratio is larger than 20 parts by mass, bloom tends to occur. The blending ratio of the molybdate compound (D) is preferably 5 to 15 parts by mass.

  When manufacturing the said flame-retardant resin composition, you may mix | blend antioxidant (E) further. In this case, the flame retardant resin composition is excellent in heat aging resistance.

  The antioxidant (E) is not particularly limited as long as it imparts excellent heat aging resistance to the flame retardant resin composition. Examples of the antioxidant (E) include tetrakis [methylene- 3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] methane, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-tert-butyl Phenyl) propionate, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 3,9-bis [2- {3- (3-tert-butyl-4 Hindered phenolic antioxidants such as -hydroxy-5-methylphenyl) propionyloxy} -1, dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] -undecane, 4,4 ′ -Thiobis (6 Alkylated thiobisphenol antioxidants such as tert-butyl-3-methylphenol) and bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, tris (2,4-di-tert. Phosphorous antioxidants such as 3-butylphenyl) phosphite and tris (nonylphenyl) phosphite, dilauryl thiodipropionate, distearyl thiodipropionate, ditridecyl-3,3′-thiodipropionate, etc. Sulfur-containing ester antioxidants, 1,1′-thiobis- (2-naphthol), 2-mercaptobenzimidazole, hydrazine derivatives and the like can be mentioned. These can be used alone or in combination of two or more. Among the antioxidants, pentaerythrityl tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is particularly preferably used.

  It is preferable that antioxidant (E) is mix | blended in the ratio of 0.05-5 mass parts with respect to 100 mass parts of said polyolefin resin (A). In this case, the flame retardant resin composition is more excellent in heat aging resistance than when the blending ratio is less than 0.05 parts by mass. Moreover, compared with the case where a mixture ratio is larger than 5 mass parts, bloom becomes difficult to occur. The blending ratio of the antioxidant (E) is more preferably 0.05 to 3 parts by mass.

  When manufacturing the said flame-retardant resin composition, additives, such as a UV degradation inhibitor, a processing aid, a color pigment, a lubricant, and carbon black, may be further blended as necessary.

  The flame retardant resin composition comprises a polyolefin resin (A), a silicone compound (B), surface-treated magnesium hydroxide particles (C) and a molybdate compound (D), and an antioxidant (E ) And the like. The kneading can be performed with a kneading machine such as a Banbury mixer, a tumbler, a pressure kneader, a kneading extruder, a twin screw extruder, a mixing roll, and the like. At this time, from the viewpoint of improving the dispersibility of the silicone compound (B), a part of the polyolefin resin (A) and the silicone compound (B) are kneaded, and the obtained master batch (silicone MB) is obtained. The remaining polyolefin resin (A), surface-treated magnesium hydroxide particles (C), molybdate compound (D), antioxidant (E) and the like may be kneaded.

  In addition, in the production of the flame retardant resin composition, the step of blending the silicone compound (B) with the polyolefin resin (A) and the surface-treated magnesium hydroxide particles (C) are blended with the polyolefin resin (A). The order of carrying out the step and the step of blending the molybdate compound (D) into the polyolefin resin (A) is not particularly limited. For example, each process may be performed step by step, or all processes may be performed simultaneously.

  Next, the inner conductor 1 is covered with the flame retardant resin composition obtained as described above. 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, the insulated wire 4 is obtained.

(sheath)
Finally, two insulated wires 4 obtained as described above are prepared, and these insulated wires 4 are covered with a sheath 3 produced using the above-mentioned flame-retardant resin composition. The sheath 3 protects the insulating layer 2 from physical or chemical damage.

  The flat cable 10 is obtained as described above.

  The present invention is not limited to the above embodiment. For example, although the flat cable 10 has two insulated wires 4 in the above embodiment, the cable of the present invention is not limited to the flat cable, and only one insulated wire 4 is provided inside the sheath 3. You may have, and you may have three or more. A resin portion made of polypropylene or the like may be provided between the sheath 3 and the insulated wire 4.

  Moreover, in the said embodiment, although the insulating layer 2 and the sheath 3 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 said above. You may be comprised with a flame-retardant resin composition.

  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 1-15 and Comparative Examples 1-11)
Table 1 shows a polyolefin resin (A), a masterbatch (silicone MB) containing a silicone compound (B), surface-treated magnesium hydroxide particles (C), a molybdate compound (D) and an antioxidant (E). Were blended in the blending amounts shown in ˜3, and kneaded at 160 ° C. for 15 minutes with a Banbury mixer to obtain a flame-retardant resin composition. In addition, in Tables 1-3, the unit of the compounding quantity of each compounding component is a mass part. Moreover, in Tables 1-3, although the compounding quantity of polyolefin resin (A) is not 100 mass parts, ethylene-vinyl acetate copolymer (EVA) which is polyolefin resin is also contained in silicone MB. The total amount of the polyolefin-based resin (A) and the amount of EVA contained in the silicone MB is 100 parts by mass.

  Specific examples of the polyolefin resin (A), silicone compound (B), surface-treated magnesium hydroxide particles (C), molybdate compound (D) and antioxidant (E) are as follows. .

(A) Polyolefin resin:
(A-1) Ethylene-ethyl acrylate copolymer (EEA), manufactured by Nippon Polyethylene Co., Ltd., trade name “RESQUEPEARL EEA A1150”
(A-2) Ethylene-vinyl acetate copolymer (EVA), manufactured by Mitsui DuPont Polychemical Co., Ltd., “Evaflex EV460”
(A-3) Polyethylene (PE), manufactured by Sumitomo Chemical Co., Ltd., Excellen GMH GH030

(B) Silicone compound:
Silicone MB based on EVA as a base resin and containing 40% by mass of silicone gum, X-22-2138B manufactured by Shin-Etsu Chemical Co., Ltd.

(C) Surface-treated magnesium hydroxide particles:
(C-1) Magnesium hydroxide surface-treated with a higher fatty acid, manufactured by Kamishima Chemical Co., Ltd., trade name “Magsees N6”, higher fatty acid content 2.5% by mass, BET specific surface area 4.7 m ² / g, Average particle size 1.1μm
(C-2) Silane coupling treatment Magnesium hydroxide, manufactured by Kamishima Chemical Co., Ltd., Magseeds S6 surface treatment amount 0.3 mass%, BET specific surface area 5.2 m ² / g, average particle size 1.0 μm
(C-3) Inorganic surface-treated magnesium hydroxide, manufactured by Kamishima Chemical Co., Ltd., Magseeds EP, surface treatment amount 0.8% by mass, BET specific surface area 3.3 m ² / g, average particle size 2.9 μm

(D) Molybdate compound:
(D-1) Calcium zinc molybdate, manufactured by Hoover Engineered Materials, Inc., trade name “Chemguard 911A”, average particle diameter of 2.7 μm
(D-2) Zinc molybdate, manufactured by Hoover Engineered Materials, Inc., trade name “Chemguard 911B”, average particle size 2.3 μm
(D-3) Calcium molybdate, manufactured by Hoover Engineered Materials, trade name “Chemguard 501”, average particle size 4.1 μm
(D-4) Ammonium molybdate, manufactured by Wako Pure Chemical Industries

(E) Antioxidant:
Pentaerythrityl tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], manufactured by BASF, Irganox 1010

Next, this flame retardant resin composition was kneaded at 160 ° C. for 15 minutes by a Banbury mixer. Thereafter, the flame retardant resin composition is put into a single screw extruder (L / D = 20, screw shape: full flight screw, manufactured by Mars Seiki Co., Ltd.), and a tubular extrudate is extruded from the extruder. A conductor (number of strands / cross-sectional area of 2 mm ² ) was coated to a thickness of 0.7 mm. Thus, an insulated wire was obtained.

  The insulated wires of Examples 1 to 15 and Comparative Examples 1 to 11 obtained as described above were evaluated for mechanical properties, flame retardancy and water resistance as follows.

<Mechanical properties>
The mechanical properties were evaluated based on the measured tensile strength of the insulated wires of Examples 1 to 15 and Comparative Examples 1 to 11 by performing a tensile test according to JIS C3005. The results are shown in Tables 1-3. In Tables 1 to 3, the unit of tensile strength was MPa, and the pass / fail criteria for tensile strength were as follows. In the tensile test, the tensile speed was 200 mm / min, and the distance between the marked lines was 20 mm.

10 MPa or more: pass less than 10 MPa: fail

<Flame retardance>
About the insulated wire of Examples 1-15 and Comparative Examples 1-11, the vertical combustion test was done based on JISC3665, and the flame retardance was evaluated. The results are shown in Tables 1-3. Here, specifically, if the length from the lower end of the upper support material that supports the insulated wire at the upper portion to the end point of carbonization is within 50 mm to 540 mm, “O” is displayed as a pass, and less than 50 mm or 540 mm In the case of exceeding, “x” was indicated as a failure.

<Water resistance>
Every 7 days after the insulated wires of Examples 1 to 15 and Comparative Examples 1 to 11 were immersed in 75 ° C. warm water, the insulated wires were taken out from the warm water and measured for insulation resistance at 500 V in 30 ° C. water. Volume resistivity was calculated. The water resistance was evaluated by continuing this for 35 days. The results are shown in Tables 1-3. Here, the volume resistivity of the test piece is displayed as "○" as a pass if 1 × 10 ¹² Ω · cm or more, and a failure is when it becomes less than 1 × 10 ¹² Ω · cm, "× ”And the number of days on which the decrease in volume resistivity was confirmed.

  From the results shown in Tables 1 to 3, the insulated wires of Examples 1 to 15 reached the acceptance criteria for all of the mechanical properties, flame retardancy, and water resistance. On the other hand, the insulated wires of Comparative Examples 1 to 11 did not reach the acceptance standard for one of mechanical properties, flame retardancy, and water resistance.

  From this, according to the method for producing a flame retardant resin composition of the present invention, a flame retardant resin composition having excellent water resistance while ensuring excellent mechanical properties and excellent flame resistance. It was confirmed that it could be manufactured.

DESCRIPTION OF SYMBOLS 1 ... Inner conductor 2 ... Insulating layer 3 ... Sheath 4 ... Insulated electric wire 10 ... Flat cable

Claims (7)

Including a flame retardant blending step of blending a flame retardant into the polyolefin resin (A),
The flame retardant blending step,
With respect to the polyolefin resin (A) 100 parts by mass of a step of compounding a silicone compound (B) in a proportion of 3 to 15 parts by weight,
A step of blending 50 to 150 parts by mass of surface-treated magnesium hydroxide particles (C) obtained by surface-treating magnesium hydroxide particles with a hydrophobic compound with respect to 100 parts by mass of the polyolefin resin (A); ,
It consists only of the step of blending the molybdate compound (D) at a ratio of 5 to 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (A) .
The molybdate compound (D) is a divalent metal salt of molybdate.
A method for producing a flame retardant resin composition.   The method for producing a flame retardant resin composition according to claim 1, wherein the hydrophobic compound is a fatty acid-containing compound.   The flame-retardant resin composition according to claim 1 or 2, wherein the divalent metal salt of molybdic acid is at least one divalent metal salt selected from the group consisting of calcium zinc molybdate and zinc molybdate. Method.   Furthermore, it comprises the process of mix | blending antioxidant (E) in the ratio of 0.01-10 mass parts with respect to 100 mass parts of said polyolefin resin (A). A method for producing a flame retardant resin composition. Including a polyolefin resin (A) and a flame retardant,
The flame retardant comprises only a silicone compound (B), surface-treated magnesium hydroxide particles (C) obtained by surface-treating magnesium hydroxide particles with a hydrophobic compound, and molybdate compound (D),
The silicone compound (B) is blended at a ratio of 3 to 15 parts by mass with respect to 100 parts by mass of the polyolefin resin (A),
The surface-treated magnesium hydroxide particles (C) are blended at a ratio of 50 to 150 parts by mass with respect to 100 parts by mass of the polyolefin resin (A).
The molybdate compound (D) is blended at a ratio of 5 to 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (A).
A flame retardant resin composition , wherein the molybdate compound (D) is a divalent metal salt of molybdate . Conductors,
An insulated wire having an insulating layer covering the conductor;
The cable in which the said insulating layer is comprised with the flame-retardant resin composition of Claim 5. Conductors,
An insulating layer covering the conductor;
A cable having a sheath covering the insulating layer;
A cable in which at least one of the insulating layer and the sheath is composed of the flame retardant resin composition according to claim 5.

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