JP5700530B2 - Flame retardant resin composition for optical drop cable jacket and optical drop cable - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a flame retardant resin composition for an optical drop cable jacket, and more specifically, has physical properties, processability and flame retardancy for coating an optical drop cable jacket, and furthermore, an oviposition tube for egg laying of a blackfish The present invention relates to a flame retardant resin composition having excellent resistance to penetration.

An optical drop cable is a cable drawn into the home from an access point (closure) provided on a trunk optical cable. It is also called a low-core optical fiber cable, and is usually supported by a support line with a main tension member. An optical fiber core wire (or a plurality of optical fiber cores) positioned between the secondary tension members is covered with a jacket having a rectangular or flat elliptical cross section with two grooves.
Perhaps because of the recent global warming, the northern limit of Kuma-Zemi moved to the north and became inhabited in Western Japan. The egg-laying tube was inserted into the outer cover of the optical drop cable laid by Kuma-Zemi, and the optical fiber core inside The damage caused by the damage has become frequent. If the optical fiber core is damaged, the signal transmission reliability is reduced and the optical drop cable cannot be used.

In conventional optical drop cables, it is difficult to use magnesium hydroxide as a flame retardant rather than a halogen flame retardant from the viewpoint of safety, mainly made of resin such as ethylene-vinyl acetate copolymer as the material of the jacket. It is common to use a flame retardant polyolefin.
In this case, it is also common to improve the compatibility between the resin and the flame retardant by blending a polyolefin resin modified with a functional group-containing compound such as an unsaturated carboxylic acid (for example, see Patent Documents 1 and 2).

  However, when a flame-retardant polyolefin mainly composed of ethylene-vinyl acetate copolymer is used as a jacket material, a material that satisfies physical properties, processability, and flame retardancy can be obtained, but a relatively soft material. However, there was a problem that it was not resistant to the oviposition puncture of the bearfish, and it was not possible to prevent damage to the internal optical fiber.

  For this reason, it is desired that the optical drop cable has resistance to puncture of the oat laying tube (hereinafter, also simply referred to as “kumazemi resistance”), and eliminates the problem of signal transmission due to piercing.

Japanese Patent Laid-Open No. 2001-166188 JP 2008-286940 A

  An object of the present invention is to provide a flame retardant resin composition for an optical drop cable for an optical drop cable, which maintains excellent physical properties, processability and flame retardancy of the resin composition required for the jacket material, and has excellent bearsemi resistance Is to provide.

  The present inventors adopted high-density polyethylene as a resin modified with an unsaturated carboxylic acid or a derivative thereof, and modified high-density polyethylene, an ethylene-α-olefin copolymer, and ethylene-vinyl acetate copolymer. By using a resin component containing a specific amount of coalesce, a resin composition that satisfies all of the physical properties, workability, flame retardancy, and kumazemi resistance required for the jacket material can be obtained. As a result of the discovery, it was confirmed that accurate evaluation could be made only by measuring the stress after entering the needle in the evaluation of the resistance against coumazemi in the resin composition, and the present invention was completed based on this finding.

That is, according to the first invention of the present invention, (A) (a-1) ethylene-hexene-1 copolymer 44 to 75% by mass, (a-2) ethylene-vinyl acetate copolymer 18 to 35% by mass. And (a-3) high-density polyethylene modified with an unsaturated carboxylic acid or a derivative thereof (hereinafter, also simply referred to as “acid-modified high-density polyethylene”) with respect to 100 parts by mass of a resin, B) 65 to 80 parts by mass of magnesium hydroxide and (C) 5 to 15 parts by mass of red phosphorus.

A second invention of the present invention is the flame retardant for an optical drop cable jacket according to the first invention, further comprising (D) 10 parts by mass or less, preferably 5 parts by mass or less of melamine cyanurate. It is an adhesive resin composition.
According to a third aspect of the present invention, there is provided the flame retardant resin composition for an optical drop cable jacket according to the first or second aspect, further comprising (E) 1 part by mass or less of silicone.
4th invention of this invention is an optical drop cable which provided the flame retardant resin composition for optical drop cable jackets of any one of 1st-3rd invention in the jacket.

The flame retardant resin composition for an optical drop cable jacket according to the present invention has excellent bearsemi resistance while maintaining good physical properties, processability and flame retardancy.
The optical drop cable of the present invention has good physical properties, workability and flame retardancy of the outer sheath constituting it, and has excellent bear resistance.

In the Example of this invention, it is explanatory drawing which shows the apparatus for evaluating the resistance to Coomasemi of a resin composition.

Hereinafter, the present invention will be described in detail.
The resin composition of the present invention contains (A) a resin, (B) magnesium hydroxide, and (C) red phosphorus as essential components.

(A) Resin:
The resin (A) constituting the resin composition of the present invention includes (a-1) an ethylene-α-olefin copolymer, (a-2) an ethylene-vinyl acetate copolymer, and (a-3) acid-modified. Made of high density polyethylene.

(A-1) Ethylene-α-olefin copolymer:
The ethylene-α-olefin copolymer used in the present invention is also called a linear ethylene-α-olefin copolymer, and is a copolymer of ethylene and an α-olefin having 3 to 12 carbon atoms. Specific examples of the α-olefin include propylene, butene-1, hexene-1, 4-methyl-pentene-1, octene-1, decene-1, dodecene-1, and the like. Examples of the ethylene-α-olefin copolymer that can be preferably used include an ethylene-butene-1 copolymer, an ethylene-hexene-1 copolymer, and an ethylene-octene-1 copolymer.
In this invention, an ethylene-alpha-olefin copolymer can be used individually by 1 type or in mixture of 2 or more types.

In addition, in order to satisfy the physical properties / processability, flame retardancy, and resistance to kumazemi of the resin composition obtained in a well-balanced manner, the melt mass flow rate of the ethylene-α-olefin copolymer used (JIS K7210 (load 2.16 kg)). ) Is preferably 0.1 to 50 g / 10 min, more preferably 0.5 to 10 g / 10 min. Further, the density of the ethylene-α-olefin copolymer (measured according to JIS K7112) is preferably 0.91 to 0.96 g / cm ³ , more preferably 0.92 to 0.95 g / cm 3. ³
A commercially available ethylene-α-olefin copolymer can be used, and can be obtained from Prime Polymer Co., Ltd., Dow Chemical Japan Co., Ltd., Nippon Polychem Co., Ltd. and the like.

(A) The proportion of the (a-1) ethylene-α-olefin copolymer in the resin is 44 to 75% by mass, preferably 50 to 70% by mass, more preferably 50 to 64% by mass. .
(A) When the proportion of the component (a-1) in the resin is less than 44% by mass, the resulting resin composition does not exhibit sufficient hardness and the resistance to coumazemi is not satisfied (Comparative Example described later) 4). On the other hand, when this ratio exceeds 75 mass%, the flame retardance of the resin composition obtained and the flexibility of the cable are affected, which is not desirable (see Comparative Example 7 described later).

(A-2) Ethylene-vinyl acetate copolymer:
As the ethylene-vinyl acetate copolymer used in the present invention, conventionally known copolymers that have been used as cable jacket materials can be used, and these can be used alone or in admixture of two or more. can do.
In addition, in order to sufficiently satisfy the physical properties, processability and flame retardancy of the obtained resin composition, the melt mass flow rate of the ethylene-vinyl acetate copolymer used (measured in accordance with JIS K7210 (load 2.16 kg)) Is preferably 0.1 to 50 g / 10 min, and more preferably 0.5 to 10 g / 10 min. Moreover, what has a vinyl acetate monomer content of 5-45 mass%, Preferably it is 10-35 mass% is used suitably.
A commercially available ethylene-vinyl acetate copolymer can be used, and can be obtained from Mitsui DuPont Polychemical Co., Ltd., Tosoh Corp., Dow Chemical Japan Co., Ltd. and the like.

(A) The ratio of the (a-2) ethylene-vinyl acetate copolymer in the resin is 18 to 35% by mass, preferably 20 to 30% by mass, and more preferably 21 to 30% by mass.
(A) If the proportion of the component (a-2) in the resin is less than 18% by mass, it affects the flame retardancy of the resulting resin composition and the filling properties of other compounds, while 35% by mass If it exceeds, the resulting resin composition will not exhibit sufficient hardness, and the resistance to coumazemi will not be satisfied (see Comparative Example 4 described later).

(A-3) Acid-modified high-density polyethylene:
The acid-modified high-density polyethylene used in the present invention is obtained by modifying high-density polyethylene with an unsaturated carboxylic acid or a derivative thereof.
In the present invention, the high density polyethylene means one having a density of 0.935 to 0.975 g / cm ³ . Since the density of the high-density polyethylene hardly changes due to acid modification, the density of the acid-modified high-density polyethylene is preferably 0.935 to 0.975 g / cm ³ .

Examples of unsaturated carboxylic acids used to obtain acid-modified high-density polyethylene include fumaric acid, acrylic acid, maleic acid, itaconic acid, methacrylic acid, sorbic acid, crotonic acid, and citraconic acid, and acid anhydrides such as anhydrous Maleic acid, itaconic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, 4-methylcyclohexene-1,2-dicarboxylic anhydride or 4-cyclohexene-1,2-dicarboxylic acid An anhydride etc. can be illustrated. Of these, maleic anhydride is desirable.
The amount of the unsaturated carboxylic acid or derivative thereof used for addition modification to the high density polyethylene is preferably in the range of 0.05 to 10% by mass with respect to the high density polyethylene.
As this addition modification method, a known method such as a solution method, a suspension method, or a melting method can be employed.

In the case of adding by the solution method among the above methods, high-density polyethylene and unsaturated carboxylic acid or a derivative thereof are added to a nonpolar organic solvent, and a radical initiator is further added and heated to a high temperature of 100 to 160 ° C. . Thereby, acid-modified high-density polyethylene can be obtained.
Examples of the nonpolar solvent used in this case include hexane, heptane, benzene, toluene, xylene, chlorobenzene, and tetrachloroethane. As radical initiators, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 and benzoyl are used. Organic peroxides such as peroxides may be mentioned.

In addition, in the case of addition modification by a suspension method, high-density polyethylene and unsaturated carboxylic acid or a derivative thereof are introduced into a polar solvent such as water, and the radical initiator is further added, and 100 ° C. or higher under high pressure. The acid-modified high-density polyethylene can be obtained by heating to a high temperature.
Further, in the case of addition modification by a melting method, a high-density polyethylene, an unsaturated carboxylic acid or a derivative thereof, and a radical initiator are used using a melt kneader commonly used in the field of synthetic resins, such as an extruder, a Banbury mixer, a kneader, and the like. An acid-modified high-density polyethylene can be obtained by melt kneading.

  In addition, in order to sufficiently satisfy the physical properties / workability and resistance to kuma-zemi of the obtained resin composition, the melt mass flow rate (measured in accordance with JISK7210 (load 2.16 kg)) of the high density polyethylene is 0.1 to 50 g. / 10 minutes, more preferably 0.5 to 10 g / 10 minutes.

Commercially available high-density polyethylene for obtaining acid-modified high-density polyethylene can be used, and can be obtained from Nippon Polyethylene Co., Ltd., Dow Chemical Japan Co., Ltd., Asahi Kasei Chemicals Co., Ltd. and the like.
Acid-modified high-density polyethylene is available from Dow Chemical Japan Co., Ltd., Mitsui Chemicals, Inc.
In the present invention, the acid-modified high-density polyethylene can be used alone or in combination of two or more.

(A) The ratio of the (a-3) acid-modified high-density polyethylene in the resin is 7 to 21% by mass, preferably 10 to 20% by mass, and more preferably 15 to 20% by mass.
(A) If the proportion of the component (a-3) in the resin is less than 7% by mass, it is not possible to obtain a resin composition that satisfies the kuma-zemi resistance and flame retardancy (see Comparative Example 5 described later). . On the other hand, if this ratio exceeds 21% by mass, the tensile fracture strain of the resulting resin composition becomes too low, causing problems in physical properties (see Comparative Example 6 described later).

(B) Magnesium hydroxide:
As the magnesium hydroxide used in the present invention, any of synthetic magnesium hydroxide produced from seawater or the like and natural ore mainly composed of magnesium hydroxide produced by pulverizing natural brucite ore is suitable. The average particle size is preferably 40 μm or less, particularly preferably 0.2 to 6 μm, from the viewpoint of dispersibility and flame retardancy.
Since the (A) resin in the resin composition of the present invention includes a nonpolar resin, the surface of the magnesium hydroxide is preferably subjected to a surface treatment.

Examples of the surface treatment agent include higher fatty acids (stearic acid, oleic acid, palmitic acid, linoleic acid, lauric acid, capric acid, behenic acid, montanic acid, etc.), higher fatty acid metal salts (sodium salt and potassium of the above higher fatty acids). Salts, aluminum salts, calcium salts, magnesium salts, zinc salts, barium salts, cobalt salts, tin salts, titanium salts, iron salts, etc.), higher fatty acid amides (amides of the above higher fatty acids), titanate coupling agents (isopropyl-tri (Dioctyl phosphate) titanate, titanium (octyl phosphate) oxyacetate, etc.), silane coupling agents (vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane Emissions, methacryloxypropyl methyl dimethoxy silane) can be exemplified.
Preferred surface treatment agents include stearic acid, calcium stearate, methacryloxypropyltrimethoxysilane and the like.
The treatment amount of the surface treatment agent with respect to magnesium hydroxide is preferably 0.5 to 5.0% by mass, more preferably 1.0 to 4.0% by mass, particularly preferably 1.5 to 3.5% by mass. is there.
When the surface treatment amount is less than 0.5% by mass, it becomes difficult to cover the entire surface of magnesium hydroxide, and the effect as a compatibilizer is reduced. On the other hand, when the surface treatment amount exceeds 5.0 mass%, the effect is saturated and the cost is increased.
The surface-treated magnesium hydroxide can use a commercially available thing, and can obtain it from Kyowa Chemical Industry Co., Ltd., Kamishima Chemical Industry Co., Ltd., etc.
In this invention, magnesium hydroxide can be used individually by 1 type or in combination of 2 or more types.

  The content of (B) magnesium hydroxide in the resin composition of the present invention is 40 to 100 parts by mass, preferably 45 to 80 parts by mass, more preferably 50 to 100 parts by mass of (A) resin. 70 parts by mass. When the content of magnesium hydroxide is less than 40 parts by mass, the resulting resin composition has an effect on flame retardancy and resistance to kuma-zemi, and when this content exceeds 100 parts by mass, the resulting resin composition becomes brittle. The physical properties, workability and flexibility will be affected.

(C) Red phosphorus:
In the present invention, red phosphorus acts as a flame retardant aid. Red phosphorus is a relatively unstable compound, and is easily ignited. Especially, it is easy to cause dust explosion, and it is easy to deteriorate the resin over time. Therefore, red phosphorus whose surface is coated with a stabilizer is suitable. Can be used for
As stabilizers, metals, metal oxides, thermosetting resins, etc. are used. Examples of metals include aluminum, iron, chromium, nickel, zinc, manganese, antimony, zirconium, titanium, etc. Examples of the oxide include zinc oxide, aluminum oxide, and titanium oxide. Furthermore, examples of the thermosetting resin include phenol resin, epoxy resin, melamine resin, urea resin, polyester resin, silicon resin, polyamide resin, and acrylic resin. As the stabilizer, one or more kinds may be used to coat the surface of the red phosphorus particles.
The surface coating amount of the stabilizer is in the range of 0.5 to 15% by mass as a metal for metal and metal oxide, and 5 to 30% by mass as a solid content as a thermosetting resin with respect to red phosphorus particles. It is desirable to design.
The average particle size of red phosphorus is preferably 50 μm or less, more preferably 1 to 40 μm, from the viewpoint of dispersibility in the resin and the effect as a flame retardant aid.
Commercially available red phosphorus can be used from Phosphorus Chemical Industry Co., Ltd., Nippon Chemical Industry Co., Ltd., etc.
In the present invention, red phosphorus may be used alone or in combination.

  The content of (C) red phosphorus in the resin composition of the present invention is 5 to 15 parts by mass, preferably 6 to 12 parts by mass, and more preferably 6 to 10 parts by mass with respect to 100 parts by mass of (A) resin. The mass part. When the content of red phosphorus is less than 5 parts by mass, the flame retardancy of the obtained resin composition is lowered, and when this content exceeds 15 parts by mass, the physical properties and processability of the obtained resin composition are affected. Out.

  The resin composition of the present invention may contain (D) melamine cyanurate and / or (E) silicone in a specific ratio together with the above essential components.

(D) Melamine cyanurate:
In order to further enhance the flame retardancy while maintaining the physical properties, processability and coomasemi resistance of the resin composition of the present invention, (A) 100 parts by mass of melamine cyanurate is blended with 100 parts by mass of the resin. can do. In order to exhibit a synergistic effect with other flame retardants, and to maintain physical properties, processability and resistance to coomasemi, the blending amount is preferably 1 to 5 parts by mass.
A commercially available melamine cyanurate can be used and can be obtained from Sakai Chemical Industry Co., Ltd.

(E) Silicone The present inventors think that if the friction of the optical drop cable jacket is lowered, it will be difficult to stop the bear jizz, and it is also convenient for wear resistance and laying work. The composition of silicone as a lubricant was examined, and as a result, it was confirmed that the composition of silicone yielded good results.
The silicone used in the present invention may have any molecular structure such as linear, branched, cyclic, network, and solid network, but a linear structure is preferred. Specific examples include silicone oil, silicone oligomer, silicone rubber, and silicone gum stock.
A commercially available silicone can be used, and can be obtained from Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Co., Ltd., and the like.
In the present invention, silicones may be used alone or in combination of two or more.
The compounding quantity of (E) silicone in the resin composition of this invention shall be 1 mass part or less with respect to 100 mass parts of (A) resin, Preferably it is 0.1-0.9 mass part.

(F) Other ingredients:
In the resin composition of the present invention, it is desirable to blend carbon black with a conventional amount for imparting weather resistance.
Examples of carbon black include graphitized carbon, furnace black, acetylene black, ketjen black, and the like, which can be obtained from Mitsubishi Chemical Corporation, Cabot Japan Co., Ltd. and the like.
It is preferable that the compounding quantity of the carbon black in the resin composition of this invention is 3-15 mass parts with respect to 100 mass parts of (A) resin, More preferably, it is 4-10 mass parts, Most preferably, it is 5-8. The mass part.

Moreover, various additives and auxiliary materials can be mix | blended with the resin composition of this invention according to the intended purpose in the range which does not impair the characteristic of this invention. These various additives and auxiliary materials include stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants other than silicone, processability improvers, fillers, dispersants, neutralizers, coloring agents. An agent etc. can be mentioned. Further, in the resin composition of the present invention, a small amount of other olefinic resins can be blended with the resin component in a range not impairing the characteristics of the present invention depending on the purpose of use.
In addition, each component which comprises the resin composition of this invention can also prepare a masterbatch and can mix | blend it.

The resin composition of the present invention contains the above essential components (A) to (C) and optional components (D) to (F) in a predetermined ratio, and the various additives and auxiliary materials as necessary. Etc. can be blended in an appropriate amount, uniformly mixed using a general method such as a kneader, a Banbury mixer, a continuous mixer or an extruder, and melt-kneaded.
Next, the optical drop cable of the present invention can be produced by extruding and coating the resin composition of the present invention to a thickness of about 1 mm on the core wire of the optical cable as a jacket layer. .

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples. In addition, the physical property value used in this specification and the evaluation physical property value evaluated in the Examples are respectively the following using the prepared resin composition or a sample obtained by press (compression) molding. This is based on the combined measurement and evaluation methods.

(1) Workability:
The melt mass flow rate was measured according to JIS K 7210 (load 21.6 kg).
From the viewpoint of processability as an outer cover material of the optical drop cable, the melt mass flow rate is preferably 15 to 50 g / 10 min.

(2) Physical properties:
A tensile test was conducted in accordance with JIS K7113, and tensile fracture stress (tensile strength) and tensile fracture strain (elongation at break) were measured.
As the jacket material of the optical drop cable, it is preferable that the tensile fracture stress is 15 MPa or more and the tensile fracture strain is 300% or more.

(3) Flame retardancy:
Conforms to JIS K6911. Samples having a thickness of 2.5 mm were prepared and evaluated according to V-0, V-1, and nonstandard (NG). The V-0 class is required for the use of the optical drop cable.

(4) Friction (only Example 1 and Examples 8-9 ):
The dynamic friction coefficient was measured according to JIS K7125.

(5) Coomasemi resistance:
The durometer hardness was measured according to JIS K-7215. It is considered that 60 or more is preferable for the use of the optical drop cable.

(6) Resistance to bear seminar (simulated evaluation):
The present inventor considers that durometer hardness does not allow sufficiently accurate evaluation of resistance to bearsemi, and confirms that stress after needle entry is important as an evaluation method. Devised.
That is, when the bear occlusion pierces the oviposition tube and observes the optical drop cable damaged by damage to the internal optical fiber, the oat occludes the oviposition tube at an angle of 20 to 40 degrees with respect to the tangent to the outer surface of the optical drop cable. The depth of the stab wound on the outer jacket was 1 mm on average. Therefore, it is considered that the stress when reaching the depth of 1 mm is the boundary stress of Coomassemi resistance. For this purpose, a 1 mm diameter Meriken needle (JIS S 3008) 1 simulating an egg laying tube of a bearfish is used from a 3 mm thick sheet obtained by press molding the resin composition using an apparatus as shown in FIG. The sample 2 was pressed at a right angle and the stress when the penetration depth of the Meriken needle 1 was 0.5 mm was measured using a load cell 3 “Shimadzu Autograph AGS-G” (manufactured by Shimadzu Corporation). It was measured. In FIG. 1, 4 is a fixing jig, and 5 is a sample table.
When the stress was measured by this method using the outer cover of the drop cable damaged by the kuma-zemi as a test piece, it was less than 2N at the point where the needle penetration depth was 0.5 mm. Taking this result into consideration, 5.5N or more was considered acceptable.

In the examples and comparative examples, the following were used as each component.
(A) Resin:
(A-1) Ethylene-hexene-1 copolymer [trade name: DHDA-1184NTJ, density = 0.935 g / cm ³ , distributor: Dow Chemical Japan Co., Ltd.]
・ (A-2) Ethylene-vinyl acetate copolymer [Brand name: NUC-3195, vinyl acetate content = 25 mass%, distributor: Dow Chemical Japan Co., Ltd.]
(A-3) Acid-modified high-density polyethylene (maleic anhydride-modified high-density polyethylene)
[Product name: AMPLIFY GR205, maleic acid modified (modified amount: 1.0 mass%), density = 0.96 g / cm ³ , distributor: Dow Chemical Japan]

(B) Magnesium hydroxide:
・ (B-1) Kisuma 5A [Stearic acid surface-treated product, distributor: Kyowa Chemical Industry Co., Ltd.]
・ (B-2) Magseeds S-4 [Silane coupling agent surface-treated product, distributor: Kamijima Chemical Co., Ltd.]

(C) Red phosphorus:
・ (C-1) Nova Excel 140F [Distributor: Phosphorus Chemical Industries, Ltd.]
・ (C-2) Hishiguard LP-F [Distributor: Nippon Chemical Industry Co., Ltd.]

(D) Melamine cyanurate:
[Product name: Stabiac MC-5S, distributor: Sakai Chemical Industry Co., Ltd.]

(E) Silicone:
[Product name: NER-1, distributor: Shin-Etsu Chemical Co., Ltd.]

(F) Other ingredients:
・ (F-1) Carbon Black [Product name: CSX-709, distributor: Cabot Specialty Chemicals]
-(F-2) Antioxidant [Pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]

(G) Resin component used in Comparative Example:
・ (G-1) High-density polyethylene [Brand name: HY430, Density = 0.956 g / cm ³ , Distributor: Nippon Polyethylene Co., Ltd.]
(G-2) Maleic anhydride-modified ethylene-hexene-1 copolymer [trade name: AMPLIFY GR213, maleic acid-modified (modified amount: 0.25% by mass), density = 0.922 g / cm ³ , distributor: Dow Chemical Japan Co., Ltd.]

< Examples 1-6 >
According to the formulation shown in Table 1 below, (a-1) ethylene-hexene-1 copolymer, (a-2) ethylene-vinyl acetate copolymer and (a-3) acid-modified high-density polyethylene (B) Magseeds S-4, (C-1) Nova Excel 140F, (F-1) Carbon Black, and (F-2) Antioxidant with respect to 100 parts by mass of the resin (A) Were added and mixed in parts by mass shown in Table 1 below, and kneaded at 180 ° C. for 10 minutes using a kneader, and granulated to an average particle size of 4 mm to obtain a resin composition of the present invention. .
In Table 1, the unit of the blending amount is “part by mass”.

< Examples 7 to 9 >
A resin composition of the present invention was obtained in the same manner as in Example 1 except that (D) melamine cyanurate and / or (E) silicone was blended according to the blending formulation shown in Table 1 below.

< Example 10 >
According to the formulation shown in Table 1 below, the type of (B) magnesium hydroxide was changed to (B-1) Kisuma 5A, and the type of (C) red phosphorus was changed to (C-2) Hishiguard LP-F. Except for this, the resin composition of the present invention was obtained in the same manner as in Example 1.

<Comparative Examples 1-7>
A comparative resin composition was obtained in the same manner as in Example 1 except that the resin component was constituted according to the formulation shown in Table 2 below. In Table 2, the unit of the blending amount is “part by mass”.
In the resin component according to Comparative Example 1, the proportion of the component (a-1) is excessively small, the proportion of the component (a-2) is excessively large, and does not contain the component (a-3).
In the resin component according to Comparative Example 2, the ratio of the component (a-1) is too small and does not contain the component (a-3).
In the resin component according to Comparative Example 3, the proportion of the component (a-1) is excessive, the proportion of the component (a-2) is excessively small, and the proportion of the component (a-3) is excessively small.
In the resin component according to Comparative Example 4, the proportion of the component (a-1) is excessively small, and the proportion of the component (a-2) is excessive.
In the resin component according to Comparative Example 5, the proportion of the component (a-3) is too small.
In the resin component according to Comparative Example 6, the proportion of the component (a-3) is excessive.
In the resin component according to Comparative Example 7, the proportion of the component (a-1) is excessive, and the proportion of the component (a-2) is excessive.

Samples for evaluation were prepared from each of the resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 7, and the processability, physical properties, flame retardancy, and coomasemi resistance were evaluated. Further, the frictional properties of Example 1 and Examples 9 to 10 were evaluated. The results are shown in Table 1 and Table 2 below.

As shown in Table 1 above, the resin compositions of the present invention obtained in Examples 1 to 10 were excellent in all of processability, physical properties, flame retardancy, and coomasemi resistance.
Moreover, the resin composition which concerns on Examples 8-9 which mix | blended (E) silicone was a thing with low friction property compared with the resin composition which concerns on Example 1 (Kumazemi is hard to stop).

On the other hand, as shown in Table 2 above, the resin composition obtained in Comparative Example 1 had low tensile fracture stress, lacked hardness, and did not have kumazemi resistance.
Moreover, the resin composition obtained in Comparative Example 2 had low tensile fracture stress, poor flame retardancy, lack of hardness, and did not have kuma-semi resistance.
Moreover, the resin composition obtained in Comparative Example 3 was inferior in flame retardancy, lacked hardness, and did not have kumazemi resistance.
Moreover, the resin composition obtained in Comparative Example 4 was inferior in flame retardancy, lacked hardness, and did not have kumazemi resistance.
In addition, the resin composition obtained in Comparative Example 5 in which the proportion of the component (a-3) was too small was insufficient in flame retardancy, and lacked hardness and did not have kumazemi resistance.
Moreover, the resin composition obtained in Comparative Example 6 in which the proportion of the component (a-3) was excessive was insufficient in physical properties (tensile fracture strain) and was brittle.
Moreover, the resin composition obtained in Comparative Example 7 in which the proportion of the component (a-1) was excessive was inferior in flame retardancy.

1 Meriken Needle 2 Sample 3 Load Cell 4 Fixing Jig 5 Sample Stand

Claims (4)

(A) (a-1) 44 to 75% by mass of an ethylene-hexene-1 copolymer , (a-2) 18 to 35% by mass of an ethylene-vinyl acetate copolymer and (a-3) an unsaturated carboxylic acid or It contains (B) 65 to 80 parts by mass of magnesium hydroxide and (C) 5 to 15 parts by mass of red phosphorus with respect to 100 parts by mass of a resin composed of 7 to 21% by mass of high-density polyethylene modified with the derivative. A flame retardant resin composition for an optical drop cable jacket.   The flame retardant resin composition for an optical drop cable jacket according to claim 1, further comprising (D) 10 parts by mass or less of melamine cyanurate.   Furthermore, (E) 1 mass part or less of silicone is contained, The flame-retardant resin composition for optical drop cable jackets of Claim 1 or 2 characterized by the above-mentioned.   The optical drop cable which provided the flame retardant resin composition for optical drop cable jackets in any one of Claims 1-3 in the jacket.

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