JP2002042555A - Ethylene resin composition and electric wire/cable coated with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene based resin composition which coats a communication electric wire/cable where a dielectric loss tangent is less than before while stability in heat-resistance is improved, and to provide a communication electric wire/cable, suitable for high-frequency transmission coated with the resin composition where the attenuation amount and dielectric loss are improved for stability in heat-resistance. SOLUTION: The ethylene resin composition, comprising an ethylene resin and antioxidant, is provided which comprises a hindered phenol type antioxidant and aryl amine type antioxidant where the antioxidant contains no ion, for coating the communication electric wire/cable. A foaming ethylene resin composition which contains a chemical foaming agent is provided for coating a foam communication electric wire/cable. Further, the communication electric wire/ cable is provided which is coated with the ethylene resin compositions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ethylene-based resin composition for covering electric wires and cables and electric wires and cables coated with the same. Ethylene resin composition for covering electric wires and cables with improved heat resistance and electric wires and cables with improved attenuation and dielectric loss suitable for high frequency signal transmission coated with the resin composition About.

[0002]

2. Description of the Related Art In recent years, coaxial cables used for insulated wires and signal transmission, LANs (Local Area Networks)
In cables (hereinafter collectively referred to simply as "wires / cables"), dielectric loss, decrease in dielectric constant and dielectric loss tangent, etc., are reduced, thereby reducing attenuation from the wires / cables and reducing image and audio transmission. Sharpening and reducing the number of repeaters are attempted. For such wires and cables,
The periphery of the core wire is covered with the coating resin composition, but the coating resin composition has a hindered phenol structure in order to ensure heat resistance during processing and use of the resin. Stabilizers such as thiobis-type antioxidants are blended. In addition, since the dielectric loss tangent of electric wires and cables is determined by the manufacturing method and structure depending on the attributes of the resin used for the coating resin composition, the coating resin composition has a small dielectric loss tangent. Ethylene-based resins are preferably employed. Further, in such electric wires and cables, a foamed resin composition is preferably used in order to reduce the amount of signal attenuation from itself.

[0003] The foaming method of the resin composition is roughly divided into
There are two methods, chemical foaming and gas foaming. In the former method, a chemical foaming agent is blended in a resin made of an ethylene resin such as a high-pressure low-density polyethylene at a temperature not higher than its decomposition temperature, and it is supplied to an extruder. This is a method in which a metal conductor is extrusion-coated, then foamed in the air, and then cooled and solidified with water or the like. The latter method is a method in which an inert gas (carbon dioxide gas, nitrogen, chlorofluorocarbon gas) is used as a foaming agent instead of a chemical foaming agent. According to this method, a high foam having a foaming ratio of about 80% can be easily obtained. Not only that, but also high-density polyethylene having high mechanical strength can be used, so that it is suitable for manufacturing high-quality cables. In the latter method, a method of using the former chemical foaming agent as a foaming aid is also known. By the way, in recent years, with the innovation of communication technology, in communication wires and cables such as the above-mentioned coaxial cable, in order to transmit more information, the frequency to be used is changed from several hundred megahertz of conventional VHF or UHF. B
It is necessary to replace S, CS, etc. with high-frequency ones or higher, such as 1 GHz or more. As a countermeasure, there is a need for durable wires and cables that have low attenuation at such high frequencies and that can withstand long-term use. Is now available. Under these circumstances, various attempts have been made to improve the problems of conventional electric wires and cables, but none of them has been sufficiently satisfactory.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is not only to suppress the increase in dielectric loss tangent of a resin composition, but also to reduce the dielectric loss while maintaining the same mechanical properties as a conventional resin composition. As a result, the amount of attenuation is 1.77 GHz, specified at 20 ° C. at 20 ° C. (JCS423 Annex 2), which is defined by the JCS (Japan Cable Manufacturers Association). For example, while passing the S-5C-FB cable standard, 377 dB / km or less), the ethylene resin composition for covering electric wires and cables having excellent heat resistance stability, and further coating the ethylene resin composition with the ethylene resin composition It is an object of the present invention to provide an electric wire / cable.

[0005]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies in order to improve the problems of conventional wires and cables, and as a result, the electricity and signals from the wires and cables have been obtained. The amount of attenuation is directly related to the dielectric loss tangent of the resin used, and at least two kinds of compounds having a specific structure are selected from among the antioxidants to be blended to produce the resin composition, and those antioxidants are selected. By combining at a specific ratio, the dielectric loss tangent of the resin composition is suppressed, and as a result, not only the attenuation can be reduced, but also the heat stability has a synergistic effect. Also,
By adding a chemical foaming agent to such a resin composition in addition to the at least two kinds of antioxidants, even if the amount of the chemical foaming agent is reduced, the same foaming ratio as that of the prior art can be achieved. The electric wire / cable coated with this resin composition is defined as a coaxial cable for receiving satellite broadcasting television of JCS (Appendix 2 of JCS423) 1.77.
It has been found that it satisfies the standard of attenuation at 20 ° C. of gigahertz and has excellent heat stability. The present invention has been completed based on these findings.

That is, the first invention of the present invention relates to an ethylene resin composition containing an ethylene resin (A) and an antioxidant (B), wherein the antioxidant (B) contains at least one kind of sulfur. Provided is an ethylene-based resin composition for covering electric wires and cables, comprising a hindered phenol-type antioxidant (B ₁ ) containing no hindered phenol and at least one arylamine-type antioxidant (B ₂ ). I do.

[0007] The second invention of the present invention provides the ethylene resin composition for covering electric wires and cables according to the first invention, which further comprises a chemical foaming agent (C).

[0008] The third invention of the present invention relates to a hindered phenol type antioxidant (B ₁ ) containing no sulfur based on 100 parts by weight of the ethylene resin.
The electric wire / cable according to the first invention, wherein the amount is 0.003 to 1.0 part by weight and the arylamine-type antioxidant (B ₂ ) is 0.003 to 1.0 part by weight. Provided is an ethylene resin composition for coating.

According to a fourth aspect of the present invention, the ratio of the antioxidant (B) to the chemical blowing agent (C) is based on 100 parts by weight of the ethylene resin, and the sulfur-free hindered phenol type antioxidant ( B ₁₎ and 0.003 parts by weight to 1.0 parts by weight, arylamine type antioxidant _(B 2) 0.003 to
2. The ethylene resin composition for covering electric wires and cables according to the second invention, wherein 1.0 part by weight and 0.03 to 3.0 parts by weight of the chemical foaming agent (C) are provided.

The fifth invention of the present invention relates to an antioxidant (B)
Is a hindered phenol type antioxidant containing no sulfur _(B 1) with respect to 20% to 80% by weight, arylamine type antioxidant _(B 2) consists 80% to 20% by weight, and, The total amount of the antioxidant (B) is 0.01 parts by weight to 1.3 parts by weight based on 100 parts by weight of the ethylene-based resin, any one of the first to fourth inventions. Provided is an ethylene resin composition for covering electric wires and cables.

According to a sixth aspect of the present invention, there is provided a sulfur-free hindered phenol-type antioxidant (B ₁ ) comprising tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-
4'-hydroxyphenyl) propionate] methane,
N, N'-bis [3- (3,5-di-t-butyl-4-
Hydroxyphenyl) propionyl] hydrazine, 1,
3,5-tris (4-t-butyl-3-hydroxy-
2,6-dimethylbenzel) isocyanuric acid and 1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene, which is at least one compound selected from the group consisting of: an arylamine type antioxidant (B ₂ )
Any one of the first to fifth inventions, which is at least one compound selected from 4,4'-bis (α, α'dimethylbenzyl) diphenylamine and 4,4'-dioctyldiphenylamine. To provide an ethylene resin composition for covering electric wires and cables.

According to a seventh aspect of the present invention, there is provided an electric wire / cable coated with the ethylene resin composition for coating an electric wire / cable according to any one of the first to sixth aspects.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

1) Ethylene resin (A) In the present invention, the ethylene resin (A) is a high-pressure low-density ethylene homopolymer, a high-density ethylene copolymer,
Examples include a medium-density ethylene copolymer, a linear low-density copolymer, and a linear ultra-low-density copolymer. These ethylene resins (A) can be prepared by known polymerization methods, respectively. In the case of a high-pressure method, the polymerization catalyst may be a radical-generating catalyst such as an organic peroxide, an azo compound, or oxygen. Examples of other polymerization methods include a Phillips catalyst, a Ziegler catalyst, a standard catalyst, and a metallocene catalyst. Α- to be copolymerized with ethylene
Examples of the olefin include propylene, butene-1, hexene-1, 4-methylpentene-1, octene-1, decene-1, dodecene-1, and the like. Ethylene resin (A) may be used alone or in combination of two or more (for example,
High-pressure method containing two or more of low-density ethylene homopolymers).

In the present invention, the density is 0.910
0.930 g / cm ³ , preferably 0.915 to 0.9
25 g / cm ³ , melt mass flow rate is 0.01
A high-pressure low-density ethylene polymer of from 10 to 10 g / 10 min, preferably from 1 to 5 g / 10 min, and a mixture of this with another ethylene-based resin, having an apparent melting point of 125 ° C., preferably less than 120 ° C. Are preferably used. These ethylene resins (A) have a foaming temperature range of 130 to 2
At 00 ° C., the melt tension is large, and there is an effect of reducing the escape of the foaming gas from the cells, and the decomposition temperature of the preferable chemical foaming agent described later is also in the range of 130 to 160 ° C.
It does not decompose at a temperature of 120 to 130 ° C. when the foamable resin composition is produced using the ethylene-based resin (A), and has an appropriate temperature of 13 when foaming the conductor with the foamable resin composition.
It is for decomposing | disassembling at 0-200 degreeC. The ethylene resin (A) used is 1 MHz (megahertz),
The dielectric loss tangent at 3 ° C. is 80 × 10 ⁻⁶ or less, preferably 65 × 10 ⁻⁶ or less, more preferably 50 × 10 ^−6.
The following can be suitably used. From the dielectric loss tangent, the amount of attenuation can be predicted, and the dielectric loss tangent is determined by the method of producing the ethylene-based resin (A) and the type of catalyst or chain transfer agent used in the production. The preferred ethylene-based resin (A) is specifically a high-pressure low-density ethylene homopolymer having a dielectric loss tangent of 44 × 10 4
^-6 NUC-766 (manufactured by Nippon Unicar), dielectric loss tangent 42 × ^{10 -6} of NUC-2460MD (manufactured by Nippon Unicar), and L-2340 of dielectric loss tangent 36 × ^{10 -6}
(Made by Asahi Kasei) and the like.

2) Sulfur-free hindered phenol type antioxidant (B ₁ ) The sulfur-free hindered phenol type antioxidant (B ₁ ) is an antioxidant having a hindered phenol structure. What is necessary is just to contain no sulfur atom in the structure, and specifically, tetrakis [methylene-3-
(3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (Irganox 1010 manufactured by Ciba Specialty Chemicals), N, N′-bis [3- (3,5-di-t) -Butyl-4-hydroxyphenyl) propionyl] hydrazine (Irganox 1024 manufactured by Ciba Specialty Chemical), 1,3
5-tris (4-t-butyl-3-hydroxy-2,6
-Dimethylbenzyl) isocyanuric acid (Cyanox 1790, Cytec), 1,3,5-trimethyl-2,4-6-tris (3,5-di-t-butyl-4-)
Hydroxybenzyl) benzene (Ethanox 330 manufactured by Albert Corporation), triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-)
Hydroxyphenyl) propionate] (Irganox 245 manufactured by Ciba Specialty Chemicals), 1,6
-Hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (Irganox 25 manufactured by Ciba Specialty Chemical Co., Ltd.)
9), octadecyl-3- (3,5-di-t-butyl-)
4-hydroxyphenyl) propionate (Irganox 1076 manufactured by Ciba Specialty Chemicals),
N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide) (Irganox 1098 manufactured by Ciba Specialty Chemicals),
1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene (Irganox 1 manufactured by Ciba Specialty Chemical Co., Ltd.)
330), tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate (Irganox 3114 manufactured by Ciba Specialty Chemicals), isooctyl-3- (3,5-di-t-butyl-) 4-hydroxyphenyl) propionate (Irganox 1135 manufactured by Ciba Specialty Chemicals), 1,1,3-
Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane (Adeka Stub AO- manufactured by Asahi Denka Co., Ltd.)
30), 4,4'-butylidenebis- (3-methyl-6
-T-butylphenol (Adeka Stub AO-40 manufactured by Asahi Denka Co., Ltd.) and the like.

Although the mechanism by which the hindered phenolic antioxidant (B ₁ ) containing no sulfur increases the dielectric loss tangent significantly less than that containing sulfur is not clear, test results clearly show the latter. Showed that the increase was large. In the present invention, one or more hindered phenol type antioxidants (B ₁ ) containing no sulfur are blended. The compounding amount of the antioxidant is 0.003 to 1.0 part by weight, preferably 0.01 to 0.5 part by weight, more preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the ethylene resin.
It is 02 parts by weight to 0.3 parts by weight. If the compounding amount of the antioxidant is smaller than the above lower limit, there is no problem in increasing the dielectric loss tangent, but the arylamine type antioxidant (B ₂ )
And the heat resistance stability becomes insufficient.
On the other hand, when the ratio exceeds the above upper limit, there is no problem in heat resistance stability, but the dielectric loss tangent is significantly increased, and the antioxidant is expensive.

[0018] 3) arylamine type antioxidant (B ₂₎ arylamine type antioxidant used in the present invention (B ₂₎ may be any one known in the secondary amine having an aryl group, specifically For example, 4,4′-bis (α, α′-dimethylbenzyl) diphenylamine (Nonflex DCD manufactured by Seiko Chemical Co., Ltd.), 4,4′-dioctyldiphenylamine (Nonflex OD manufactured by Seiko Chemical Co., Ltd.), phenyl- 1-naphthylamine (Knok rack PA manufactured by Ouchi Shinko Co., Ltd.), N, N'-di-2-naphthyl-p-phenylenediamine (Knoc rack white manufactured by Ouchi Shinko Co., Ltd.), N, N'-diphenyl-p-phenylene Diamine (Knok Luck DP manufactured by Ouchi Shinko), N-phenyl-N'-isopropyl-p-phenylenediamine (Knok Luck 810- manufactured by Ouchi Shinko) A), N-phenyl--N '- (1,3-dimethylbutyl)-p-phenylenediamine (Ouchi Shinko Co. knock rack 6C),
N-phenyl-N '-(3-methacryloyloxy-2
-Hydroxypropyl) -p-phenylenediamine (Knok rack G-1 manufactured by Ouchi Shinko Co., Ltd.) and the like.

In the present invention, one or more kinds of arylamine type antioxidants (B ₂ ) are blended. The amount of this antioxidant is 0.00 0.00 parts by weight of the ethylene resin.
3 parts by weight to 1.0 part by weight, preferably 0.01 parts by weight
0.5 parts by weight, more preferably 0.02 parts by weight to 0.1 part by weight.
3 parts by weight. If the compounding amount of this antioxidant is smaller than the above lower limit, there is no problem in increasing the dielectric loss tangent,
The synergistic effect with the hindered phenol type antioxidant is lost, and the heat resistance becomes insufficient. On the other hand, when the ratio exceeds the above upper limit, there is no problem in heat resistance stability, but the dielectric loss tangent is increased, and the antioxidant is expensive, so that the economic efficiency is lowered, which is not preferable. The mixing ratio of the sulfur-free hindered phenol type antioxidant (B ₁ ) and the arylamine type antioxidant (B ₂ ) may be arbitrary, but the former 2
The range of 80 to 20% by weight is desirable for the range of 0 to 80% by weight. If one of them is less than 20% by weight, synergistic effects such as a decrease in dielectric loss tangent and an increase in oxidation induction period due to the combination of both become insignificant. The mixing ratio of both is 50:50
Is preferable because the synergistic effect is more likely to appear.
The total amount of the hindered phenol type antioxidant (B ₁ ) containing no sulfur and the arylamine type antioxidant (B ₂ ) is based on 100 parts by weight of the ethylene resin.
0.01 to 1.3 parts by weight, preferably 0.02 to 1.0
Parts by weight. If the amount is less than 0.01 part by weight, the heat resistance becomes insufficient, and if it exceeds 1.3 parts by weight, the dielectric loss tangent value increases, and the characteristics of electric wires and cables deteriorate, which is not desirable.

4) Chemical blowing agent (C) The chemical blowing agent (C) used in the present invention is thermally decomposed to give N
It generates an inert gas such as H ₃ , N ₂ , CO _2, etc., and foams the ethylene resin. For example, p, p′-oxy-bis-benzenesulfonylhydrazide, azodicarbonamide, N, N′- Examples thereof include dinitrosopentamethylenetetramine and azobisisobutyronitrile. The chemical foaming agent (C) may be used alone or in combination.
A mixture of more than one species may be used. In the present invention, p, p'-oxy-bis-benzenesulfonylhydrazide (hereinafter referred to as O
Called BSH. ) Or a mixture of azodicarbonamide (hereinafter referred to as ADCA) treated with OBSH and a foaming aid (0.3 parts by weight or less of ADCA per 1 part by weight of OBSH) is preferably used. Since these have a lower decomposition temperature than other chemical foaming agents, the appropriate foaming temperature of the foamable resin composition of the present invention is 130.
This is because it can be sufficiently decomposed at ~ 200 ° C to generate a foaming gas.

The foaming aid treatment refers to salicylic acid, stearic acid, their zinc salts, magnesium salts and the like.
It means that 0.0003 to 0.6 parts by weight are mixed with 1 part by weight of CA and mixed at 30 to 80 ° C. by a mixer such as a ribbon mixer. The compounding amount of the chemical foaming agent is 0.03 to 3.0 parts by weight, preferably 0.5 to 2.0 parts by weight, based on 100 parts by weight of the ethylene resin. When the compounding amount of the chemical blowing agent is smaller than the above lower limit, the foaming ratio becomes small and non-uniform, and the effect of compounding the chemical blowing agent is reduced. Since the dielectric loss tangent of the composition is greatly increased, the amount of attenuation is rather increased, and the effect of foaming may not be seen. In addition, it is not preferable in terms of overfoaming and economy.

5) Other Ingredients The ethylene resin composition of the present invention may contain various additives and auxiliary materials according to the purpose of use as long as the properties of the present invention are not impaired. These various additives and auxiliary materials include stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, lubricants, processability improvers, fillers, dispersants, copper damage inhibitors, neutralizing agents, and chemical foaming agents. Examples of the agent include an impurity trapping agent, a bubble inhibitor, and a coloring agent. Further, the ethylene-based resin composition of the present invention may contain a small amount of another olefin-based resin in the base ethylene-based resin within a range that does not impair the properties of the present invention, depending on the purpose of use.

6) Ethylene resin composition The ethylene resin composition of the present invention comprises a predetermined amount of the above components,
That is, an appropriate amount of the ethylene resin (A), the antioxidant (B), the chemical foaming agent (C) if necessary, and the various additives and auxiliary materials as needed are mixed in a general method. For example, it can be prepared by uniformly mixing and kneading using a kneader, a Banbury mixer, a continuous mixer or an extruder. If the preparation method is specifically illustrated, using a Banbury mixer, kneading is performed at a temperature equal to or higher than the melting point of the ethylene-based resin, and when a chemical blowing agent is used, a predetermined amount of the chemical blowing agent is then added. Then, it can be kneaded at a temperature lower than the decomposition temperature of the chemical foaming agent, cooled to form a sheet, and the sheet can be cut into pellets. Alternatively, the mixture may be similarly kneaded using an extruder, extruded, formed into a columnar material, and cut into pellets. The ethylene-based resin composition of the present invention can be used without foaming (solid) by foaming by a chemical foaming method, a gas foaming method, or a combined foaming method. The ethylene-based resin composition of the present invention can be coated as an insulating coating layer on a metal conductor such as copper or aluminum by a known cable coating method. Specifically, the pellets prepared as described above are supplied to an extruder, and a molten ethylene-based resin composition obtained by heating to a predetermined temperature is coaxially extruded onto a preheated metal conductor, and the ethylene-based resin composition is extruded. A film of the resin composition can be formed. When a pellet containing a chemical foaming agent is used, the pellet is heated to a temperature not lower than the decomposition temperature of the chemical foaming agent and extruded to form a foamed insulating ethylene film. In the case of the gas foaming method, foaming can be performed by a known method using an inert gas to form a foamed insulating film. These various parameters in the cable (electric wire) coating method can be easily determined by those skilled in the art.

[0024]

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples of the present invention, but the present invention is not limited to these examples. The physical property values used in the present specification and the evaluated physical property values evaluated in Examples and the like are based on the measurement methods summarized below.

[Measurement method] Melt mass flow rate Performed in accordance with JIS K 6922-2.
The measurement was performed at 6 kg and a measurement temperature of 190 ° C. 2. Density was performed in accordance with JIS K 6922-2. 3. The dielectric loss tangent was measured in accordance with JIS K 6922-2, and a voltage rise ratio method (Q meter method) was employed. 150 kg / cm ² , 14
1mm obtained by compression molding for 5 minutes after preheating at 0 ° C for 3 minutes
Two 100 mm × 68 mm square samples were prepared from the thick sheet and measured at 1 MHz and 23 ° C.

4. Heat Stability Oxidation Induction Time (OIT) The heat stability was evaluated by the oxidation induction time (OIT) according to ASTM-D150. 5 mg of a sample was weighed from a 1 mm-thick sheet prepared in the same manner as in the measurement of dielectric loss tangent, and both a reference and a sample were subjected to differential scanning calorimetry using an aluminum pan under a nitrogen atmosphere at a flow rate of 100 ml / min.
The temperature was raised to 210 ° C. at 50 ° C. per minute, and after the temperature was maintained for 5 minutes, the air flow rate was introduced at 100 ml / min. OIT indicates the resistance of the resin composition to oxidation and serves as an index of heat resistance. The larger the value, the better the thermal stability. 5. Relative dielectric constant The dielectric constant was measured in accordance with JIS K 6922-2 in the same manner as the dielectric loss tangent. 6. For the non-foamed resin composition, based on JIS C 3051 high-frequency coaxial cable (polyethylene insulation braided type), the obtained resin composition is coated on an inner conductor made of a copper wire, a core is formed, and a core is formed. A 5D-2V cable in which a braid of a soft copper wire was applied as a conductor and a sheath made of a vinyl chloride resin was further coated on the outside thereof was prepared and evaluated. Regarding the foamed resin composition, JIS C 3502
Performed in accordance with, coated on the inner conductor made of a copper wire with the foamable resin composition comprising the resin composition of the present invention, and further applied a double-sided aluminum foil-clad plastic tape and a tin-plated soft copper wire braid as an outer conductor, An S-5C-FB cable 100 m coated with a sheath material made of a vinyl chloride resin was formed thereon and evaluated. The attenuation was measured using a network analyzer 8753E manufactured by Hewlett-Packard Co., and the attenuation was in dB /
Expressed in km. A large amount of attenuation means that the attenuation at that frequency is large, and that the transmitted signal is greatly attenuated and its quality is greatly degraded.

7. Antioxidant The antioxidant (B) used is as follows.
In the examples and comparative examples, the names are given.
You.Sulfur-free hindered phenolic antioxidant
(B ₁ )  (1) A-1 tetrakis [methylene-3- (3 ',
5'-di-t-butyl-4'-hydroxyphenyl) p
Lopionate] Methane (Ciba Specialty Chemical Co., Ltd.)
Manufactured by Irganox 1010 (Irganox 101
0)) (2) A-2 N, N'-bis [3- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionyl] hydrido
Razine (Irganok, Ciba Specialty Chemical Co., Ltd.)
1024 (Irganox 1024)) (3) A-3 1,3,5-tris (4-t-butyl-
3-hydroxy-2,6-dimethylbenzel) isocyan
Nullic acid (Cyanec Cyanox 1790 (C
yanox1790)) (4) A-4 1,3,5-trimethyl-2,4,6-
Tris (3,5-di-t-butyl-4-hydroxyben
Sil) benzene (Ethano manufactured by Albert Corporation)
Box 330 (Ethanox 330)Arylamine type antioxidant (B ₂ )  (1) B-1 4,4'-bis (α, α 'dimethylben
Jill) diphenylamine (Non-fleck manufactured by Seiko Chemical Co., Ltd.)
DCD (NonflexDCD)) (2) B-2 4,4'-dioctyldiphenylamine
(Nonflex OD manufactured by Seiko Chemical Co., Ltd.
OD)) Antioxidants used in Comparative Examples (hinder containing sulfur
(1) C-14,4'-thiobis- (6-t-butyl)
-3-methylphenol) (Sino, manufactured by Cipro Kasei Co., Ltd.)
(Senox BSC)) (2) C-2 2,2'-thio-diethylenebis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] (manufactured by Ciba Specialty Chemical Co., Ltd.)
 Irganox 1035 (Irganox103
5))

Examples 1 to 5 High pressure method low density ethylene homopolymer (Nippon Unicar N
UC-766, melt mass flow rate 2.0 g / 10
Min, density 0.922 g / cm ³ , dielectric loss tangent 44 × 10
^-6 , a dielectric constant of 2.2823), sulfur-free hindered phenol-type antioxidant A-1 and arylamine-type antioxidant B-1 in a weight ratio of 1: 1.
Blended as shown in Table 1 and mixed using a Brabender mixer.
The mixture was melt-kneaded at 40 ° C. for 10 minutes to obtain an ethylene-based resin composition of the present invention. A sheet having a thickness of 1 mm was prepared from the obtained resin composition, and the electrostatic tangent and the oxidation induction time (OIT) of the obtained sheet were measured. The results are shown in Table 1.

[0029]

[Table 1] As is evident from Table 1, the ethylene-based resin composition of the present invention contains a sulfur-free hindered phenol-type antioxidant and an arylamine-type antioxidant in an amount of 0.02 respectively.
Even when 75 parts by weight and a total of 0.15 parts by weight are mixed, the increase from the ethylene resin used as the base resin of the dielectric loss tangent is about 24 × 10 ⁻⁶ , which is smaller than the comparative example described later. There were few. On the other hand, the oxidation induction time (O
IT) is 51.2 minutes even when 0.025 parts by weight of the antioxidant is added and 0.05 parts by weight in total, which is remarkably longer than that of a comparative example described later, and has excellent heat stability. Was what it was.

Comparative Examples 1 to 3 The antioxidants were used alone, and the amounts were 0.07 parts by weight (Comparative Example 1), 0.1 parts by weight (Comparative Example 2) and 0.15 parts by weight (Comparative Example). A test similar to that of Example 1 was performed except that 3) was performed, and a dielectric loss tangent and an oxidation induction time (OIT) were measured in the same manner. The results are shown in Tables 2 to 4. As is clear from Tables 2 to 4, the ethylene-based resin composition containing C-1 and C-2, which are thiobis-type antioxidants having a hindered phenol structure, is more oxidized than the ethylene-based composition of the present invention. The induction time was 50 minutes with 0.07 parts by weight and was usable, but the increase in dielectric loss tangent was large. A-1, A-2, A-3, A-, a sulfur-free hindered phenolic antioxidant
4, the increase in dielectric loss tangent was almost the same as that of the ethylene resin composition of the present invention, but the oxidation induction time (OIT) was lower than that of the same amount. It was small and inferior in heat stability. this is,
This is because an arylamine-type antioxidant (B-1, B-2, etc.) is not used in combination. Although the dielectric loss tangent value of the ethylene resin composition containing each of the arylamine-type antioxidants B-1 and B-2 alone was small and good, the oxidation induction time (OIT) was very low. And was inferior in heat resistance stability and was not practical. this is,
This is because a hindered phenol-type antioxidant containing no sulfur (A-1, A-2, A-3, A-4, etc.) is not used in combination.

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

Examples 6 to 10 The same tests as in Example 1 were carried out, and as shown in Table 5, the hindered phenol type antioxidant A-
The evaluation was performed in the same manner as in Example 1 by combining 1, A-2, A-4 and the arylamine-type antioxidants B-1 and B-2 while changing the blending amount. In this test, the relative permittivity was also measured. The results are shown in Table 5. As is clear from Table 5, 0.018 parts by weight of the antioxidant A-1 was used,
Example 6, A-1 containing 0.053 parts by weight of B-1
Of the ethylene-based resin composition of Example 7 in which 0.053 parts by weight of B-1 and 0.018 parts by weight of B-1 were blended, the increase in dielectric loss tangent was small, and the oxidation induction time (OIT) was low.
-1 and B-1 were longer than plain and excellent in heat stability. Further, each of A-1 and B-2 is 0.0
The ethylene of the present invention of Examples 8 to 10 in which 5 parts by weight of the composition, 0.05 parts by weight of each of A-2 and B-1 and 0.05 parts by weight of each of A-4 and B-1 were used. The resin composition also had good dielectric loss tangent and oxidation induction time (OIT). The relative permittivity of the ethylene-based resin composition obtained in these examples is 2.28 of the base resin.
It was almost equivalent to 23, and it was confirmed that it was good.

[0035]

[Table 5]

Examples 11 to 13 and Comparative Example 4 The ethylene resin used in Example 1 was mixed with calcium stearate as an antioxidant and a lubricant as shown in Table 6 and then mixed with a Banbury mixer.
Kneading was performed at rpm until the temperature rose to 116 ° C. The obtained molten resin composition is extruded at 126 ° C. using an extruder, and the columnar material is cut in water to have a diameter of 3 mm and a length of about 3 mm.
mm pellets were obtained. Example 1
A sheet was prepared in the same manner as described above, and the dielectric loss tangent was measured.
In addition, this pellet was extruded into a 50 mmφ extruder (L / D = 2).
4), a cylinder temperature of 130 ° C. in the supply area, a cylinder temperature of 140 ° C. in the compression area, and a cylinder temperature of 147 ° C. in the metering area. And extruded to obtain a foam insulated coaxial cable core having an outer diameter of 5.1 mm. For the obtained core, only the resin composition portion was sampled, the weight was measured, the weight was further measured in water, and the volume was calculated.
From this, the foaming rate was evaluated. As shown in Table 6, the ethylene resin composition of the present invention showed a significantly smaller value than the dielectric loss tangent of 211 × 10 ⁻⁶ of the resin composition using C-1 of Comparative Example 4, as shown in Table 6. Was. Further, as is clear from the test results, the chemical foaming agent was found to greatly increase the dielectric loss tangent, but the ethylene resin composition of the present invention has a larger chemical foaming agent than the comparative example. 10 amount
It was shown that the same level of foaming ratio could be achieved even when the percentage was reduced, and thus a favorable effect on foaming and an effect of further reducing the dielectric loss tangent were confirmed.

[0037]

[Table 6]

Examples 14 to 15 and Comparative Example 5 NUC-76 used in Examples as an ethylene resin was used.
6 and L-2340 (manufactured by Asahi Kasei, high pressure method low density ethylene homopolymer, melt mass flow rate 3.8 g / 10 min,
Density 0.923 g / cm ³ , dielectric loss tangent 36 × 10 ⁻⁶ ,
Using a dielectric constant of 2.2829), calcium stearate was blended as an antioxidant and a lubricant in the formulations shown in Table 7, and pellets were obtained in the same manner as in the examples.
A sheet was prepared from the pellet in the same manner as in Example 1, and the dielectric loss tangent was measured. In addition, this pellet
It is supplied to an extruder (L / D = 24) of 0 mmφ, extruded and coated on a copper core wire at a wire winding speed of 25 m / min, and has an outer diameter of 4.8.
mm insulated coaxial cable core was obtained. Using the obtained core, a 5D-2V cable was prepared, and the attenuation at 10 wavelengths was measured. As shown in Table 7, the results show that the resin composition using C-1 of Comparative Example 5 had a dielectric loss tangent of 119 × 10
Compared with ^-6 , the ethylene-based resin composition of the present invention showed a significantly smaller value. In addition, the oxidation induction time (OIT)
It was better than the comparative example. Further, as is clear from the test results, the attenuation was superior to that of the comparative example, and the coaxial cable was of high quality.

[0039]

[Table 7]

Example 16 and Comparative Examples 6 and 7 As shown in Example 16 and Comparative Examples 6 and 7 in Table 8, ethylene resin, antioxidant lubricant (calcium stearate)
Were blended, and kneaded in the same manner as in Example 11, and OBSH was blended in the blended amount shown in each of the resultant kneaded materials,
As in Example 11, pellets having a pre-expansion degree of 4% were obtained.
A sheet was similarly prepared using the pellets, and the dielectric loss tangent and the oxidation induction time (OIT) were measured. Separately, the pellets are fed to a 50 mmφ extruder (L / D = 24), the cylinder temperature in the supply area is set to 130 ° C., the cylinder temperature in the compression area is set to 140 ° C., and the cylinder temperature in the measurement area is set to 147 ° C. It was extrusion-coated at a winding speed on a copper core wire preheated to 70 ° C. to obtain a foamed insulated coaxial cable core having an outer diameter of 5.1 mm. The foaming rate of this coaxial cable core was measured. Around this coaxial cable core,
The S-5C-FB cable 100m was prepared and evaluated by the method described in the attenuation evaluation method. As shown in Table 8, the ethylene-based resin composition of the present invention showed Comparative Example 6,
Compared with No. 7, the increase in dielectric loss tangent was small, the oxidation induction time was long, and excellent electrical characteristics and heat resistance stability were obtained. The foaming rate was 52.0% in Example 16 in which 1.0 part by weight of the chemical foaming agent OBSH was blended, and Comparative Example 6 (44.6% in foaming rate) with 1.13% in which the same amount was blended. As apparent from Comparative Example 7 (foaming rate: 49.8%), the foamable ethylene-based resin composition had little hindrance to foaming, and thus showed that the increase in dielectric loss tangent could be further reduced. From the obtained coaxial cable, in the measurement of the amount of attenuation, the expandable ethylene-based resin composition and the coaxial cable of the present invention show smaller attenuation as compared with the comparative example, and are particularly excellent in high-frequency transmission. there were.

[0041]

[Table 8]

[0042]

The ethylene resin composition of the present invention has a small increase in dielectric loss tangent, that is, a small amount of attenuation, and furthermore has a higher heat stability than conventional ones. Even if the amount of the foaming agent is reduced, the same foaming rate can be obtained, so it is an excellent material for the insulation layer of insulated wires, communication wires and cables, and the sheath layer. The obtained wires and cables have a small amount of attenuation, and therefore have a small dielectric loss, can efficiently transmit electricity and signals, can reduce the number of repeaters, and can transmit high-quality signals. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08K 5/18 C08K 5/18 C08L 23/04 C08L 23/04 H01B 7/29 H01B 11/00 J 11 / 00 7/34 A F-term (reference) 4F074 AA17A AA25A AD12 AD13 BA13 BA14 BA17 CA22 CC22X DA24 DA48 4J002 BB031 BB051 BB151 EJ016 EJ036 EN077 EQ018 EQ026 ES008 ET008 EU196 EV268 FD076 FD077 BA1411 305 CD09 CD20 5G315 CA02 CB02 CB06 CC08 CD02 CD17

Claims (7)

[Claims] 1. An ethylene-based resin composition containing an ethylene-based resin (A) and an antioxidant (B), wherein the antioxidant (B) is a hindered phenol-type antioxidant not containing at least one kind of sulfur. An ethylene resin composition for covering electric wires and cables, comprising an agent (B ₁ ) and at least one kind of arylamine type antioxidant (B ₂ ). 2. The ethylene resin composition for covering electric wires and cables according to claim 1, further comprising a chemical foaming agent (C). 3. The ratio of the antioxidant (B) is from 0.003 parts by weight of the sulfur-free hindered phenol type antioxidant (B ₁ ) to 100 parts by weight of the ethylene resin.
1.0 part by weight, and an arylamine type antioxidant (B ₂ )
The ethylene-based resin composition for covering electric wires and cables according to claim 1, wherein the amount is 0.003 parts by weight to 1.0 part by weight. 4. The ratio of the antioxidant (B) and the chemical blowing agent (C) is based on 100 parts by weight of the ethylene-based resin, and is a hindered phenol-type antioxidant (B ₁ ) containing no sulfur.
And 0.003 parts by weight to 1.0 parts by weight, arylamine type antioxidant _(B 2) and 0.003 to 1.0 parts by weight, the chemical foaming agent (C) in 0.03 to 3.0 parts by weight The ethylene-based resin composition for covering electric wires and cables according to claim 2, wherein: 5. An antioxidant (B) comprising 20% by weight of a sulfur-free hindered phenol type antioxidant (B ₁ )
Relative to 80% by weight, arylamine type antioxidant _(B 2) consists 80 wt% to 20 wt%, and the total amount of the antioxidant (B), per 100 parts by weight of ethylene-based resin The ethylene-based resin composition for covering electric wires and cables according to any one of claims 1 to 4, wherein the amount is 0.01 part by weight to 1.3 parts by weight. 6. A sulfur-free hindered phenolic antioxidant (B ₁ ) is tetrakis [methylene-3-
(3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, N, N′-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,3,5-tris (4-t
-Butyl-3-hydroxy-2,6-dimethylbenzene) isocyanuric acid and 1,3,5-trimethyl-
At least one compound selected from the group consisting of 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, and an arylamine-type antioxidant (B ₂ ) Is at least one compound selected from 4,4′-bis (α, α′dimethylbenzyl) diphenylamine and 4,4′-dioctyldiphenylamine.
Item 10. The ethylene resin composition for covering electric wires and cables according to item 9. 7. An electric wire or cable coated with the ethylene resin composition for coating an electric wire or cable according to any one of claims 1 to 6.