JP2018139192A - LAN cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a LAN cable that has high flame retardancy and well elongates at a low temperature.SOLUTION: A LAN cable has a sheath, and a wire being accommodated in the sheath and coated with an insulator. The LAN cable further has, between the sheath and the wire, an intermediate layer with a rate of mass decrease at 500°C of 10 mass% or less and a rate of mass decrease at 600°C of 50 mass% or less. The insulator contains polyethylene with a dielectric constant of 2.5 or less. The sheath contains a flame retardant of 150 pts.mass or more relative to a polyolefin-based polymer 100 pts.mass.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to LAN cables.

  The LAN cable is used for constructing a LAN (Local Area Network). The LAN cable includes a sheath and an electric wire housed in the sheath and covered with an insulator (see Patent Document 1). As the material for the sheath, EVA (ethylene-vinyl acetate copolymer) having a VA (vinyl acetate) amount of 20% or more is generally used.

Japanese Patent Laying-Open No. 2015-4025

  The LAN cable is required to have flame retardancy. In particular, high flame resistance is required in order to comply with overseas standards. In order to increase the flame retardancy of the LAN cable, the sheath is filled with a flame retardant. However, when a sheath containing EVA as a main component is filled with an amount of a flame retardant sufficient to impart sufficient flame retardancy, the elongation of the sheath at low temperatures is reduced.

  An object of one aspect of the present disclosure is to provide a LAN cable having high flame retardancy and large elongation at low temperatures.

  One aspect of the present disclosure is a LAN cable including a sheath and an electric wire housed in the sheath and covered with an insulator, and a mass decrease at 500 ° C. between the sheath and the electric wire. The intermediate layer having a rate of 10% by mass or less and a mass decrease rate at 600 ° C. of 50% by mass or less, wherein the insulator includes polyethylene having a dielectric constant of 2.5 or less, and the sheath includes The LAN cable contains 150 parts by mass or more of a flame retardant with respect to 100 parts by mass of the polyolefin polymer.

2 is a cross-sectional view illustrating a configuration of a LAN cable 1. FIG.

An embodiment of the present disclosure will be described.
1. Configuration of LAN Cable A LAN cable according to the present disclosure includes a sheath and an electric wire housed in the sheath and covered with an insulator. An intermediate layer having a mass reduction rate at 500 ° C. of 10% by mass or less and a mass reduction rate at 600 ° C. of 50% by mass or less is further provided between the sheath and the electric wire. The insulator includes polyethylene having a dielectric constant of 2.5 or less. The sheath contains 150 parts by mass or more of a flame retardant with respect to 100 parts by mass of the polyolefin-based polymer. The LAN cable of the present disclosure has high flame retardancy and high elongation at low temperatures by having the above configuration.

2. Sheath The sheath includes 100 parts by mass of a polyolefin-based polymer and 150 parts by mass or more of a flame retardant. The polyolefin-based polymer is a base polymer of the sheath. Examples of polyolefin polymers include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), linear very low density polyethylene (VLDPE), high density polyethylene (HDPE), polypropylene (PP), and ethylene-acrylic. Ethyl acid copolymer (EEA), ethylene-vinyl acetate copolymer (EVA), ethylene-styrene copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-butene-1 copolymer, ethylene-butene-hexene Copolymer, ethylene-propylene-diene terpolymer (EPDM), ethylene-octene copolymer (EOR), ethylene copolymer polypropylene, ethylene-propylene copolymer (EPR), poly-4-methyl- Pentene-1, maleic acid grafted low density polyethylene, hydrogenated styrene-butadiene copolymer (H-SBR), maleic acid group Straight chain low density polyethylene, copolymer of ethylene and α-olefin having 4 to 20 carbon atoms, ethylene-styrene copolymer, maleic acid grafted ethylene-methyl acrylate copolymer, maleic acid grafted ethylene-vinyl acetate Copolymers, ethylene-maleic anhydride copolymers, ethylene-ethyl acrylate-maleic anhydride terpolymers, ethylene-propylene-butene-1 terpolymers based on butene-1 It is done. As the polyolefin-based polymer, EVA is preferable, and EVA having a VA amount of 20% to 50% is particularly preferable. As the polyolefin polymer, any one kind of EVA may be used alone, or two or more kinds of EVA may be blended and used.

  As flame retardants, metal hydroxides such as magnesium hydroxide, aluminum hydroxide and calcium hydroxide, amorphous silica, zinc compounds such as zinc stannate, zinc hydroxystannate, zinc borate, zinc oxide, etc., boric acid Intimate difficulties consisting of a mixture of boric acid compounds such as calcium, barium borate, barium metaborate, etc., phosphorus flame retardants, nitrogen flame retardants such as melamine cyanurate, and components that foam and solidify during combustion A flame retardant etc. are mentioned. The flame retardant is preferably a metal hydroxide, and particularly preferably magnesium hydroxide. When magnesium hydroxide and / or aluminum hydroxide is included as a flame retardant, the flame resistance of the LAN cable is further improved.

  Any one of the above flame retardants may be used alone, or two or more may be blended. For example, magnesium hydroxide and aluminum hydroxide may be blended and used. The flame retardant may be surface-treated with a silane coupling agent, a titanate coupling agent, a fatty acid such as stearic acid or calcium stearate, a fatty acid metal salt, or the like.

  The addition amount of the flame retardant is 150 parts by mass or more with respect to 100 parts by mass of the polyolefin-based polymer. By being 150 mass parts or more, the flame retardance of a LAN cable improves. Although the upper limit in the addition amount of a flame retardant is not specifically limited, 250 mass parts or less are preferable. By suppressing the amount of flame retardant added, the elongation of the sheath at a low temperature can be further increased.

  The sheath further contains additives such as an antioxidant, a metal deactivator, a cross-linking agent, a cross-linking aid, a lubricant, an inorganic filler, a compatibilizing agent, a stabilizer, carbon black, and a colorant as necessary. You may go out. Further, the sheath may be cross-linked by an organic peroxide or by a radiation such as an electron beam.

  Although it does not specifically limit as antioxidant, For example, a phenol type, sulfur type, amine type, phosphorus type antioxidant, etc. are mentioned. The phenolic antioxidant is not particularly limited. For example, dibutylhydroxytoluene (BHT), pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3, 5-tris (3,5-di-t-butyl-4-hydroxy-benzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, thiodiethylenebis [3- (3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate] and the like, more preferably pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate]. .

  The sulfur-based antioxidant is not particularly limited. [Methylene-3- (dodecylthio) propionate] methane and the like, and tetrakis [methylene-3- (dodecylthio) propionate] methane is more preferable. Any one of these antioxidants may be used alone, or two or more thereof may be blended and used.

  The metal deactivator has the effect of stabilizing metal ions by chelate formation and suppressing oxidative degradation. The structure of the metal deactivator is not particularly limited. For example, N- (2H-1,2,4-triazol-5-yl) salicylamide, dodecanedioic acid bis [N2- (2-hydroxybenzoyl) hydrazide], 2 ′, 3-bis [[3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionyl]] propionohydrazide and the like, more preferably 2 ′, 3-bis [[ 3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionyl]] propionohydrazide.

Although it does not specifically limit as a crosslinking adjuvant, For example, a trimethylol propane trimethacrylate (TMPT), triallyl isocyanurate (TAIC), etc. are mentioned.
Although it does not specifically limit as a lubricant, For example, a fatty acid, a fatty acid metal salt, a fatty acid amide etc. are mentioned, Specifically, a zinc stearate is mentioned. Any one of these lubricants may be used alone, or two or more thereof may be blended and used.

  Although it does not specifically limit as carbon black, For example, carbon black for rubber | gum (N900-N100: ASTM D 1765-01) etc. are mentioned. Although it does not specifically limit as a coloring agent, For example, the color masterbatch for non-halogen etc. are mentioned.

3. Electric wires Electric wires are housed in sheaths. The electric wire is covered with an insulator. The insulator includes polyethylene having a dielectric constant of 2.5 or less. When the dielectric constant of polyethylene is 2.5 or less, the capacitance of the insulator is reduced. This further improves the transmission characteristics of the LAN cable. The dielectric constant of the entire insulator is preferably 2.5 or less. In this case, the transmission characteristics of the LAN cable are further improved.

  Polyethylene is not particularly limited as long as the dielectric constant is 2.5 or less. For example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), linear very low density polyethylene (VLDPE), high Density polyethylene (HDPE) etc. are mentioned, Low density polyethylene is more preferred, and low density polyethylene having a density of 0.930 or less and MFR of 0.30 or less is particularly preferred. Any one of the above polyethylenes may be used alone, or two or more thereof may be blended and used.

  The insulator may further contain an antioxidant, a copper damage inhibitor, a colorant and the like. The addition amount of the antioxidant, the copper damage inhibitor, the colorant and the like is not particularly limited, but an addition amount that makes the dielectric constant of the whole insulator 2.5 or less is preferable. The amount of the colorant added is preferably 5% by mass or less, and more preferably 2% by mass or less.

  Polyethylene may be foamed using a known technique. For example, polyethylene can be foamed by using an inert gas such as nitrogen or a chemical foaming agent such as ADCA. When polyethylene is foamed, the flame resistance of the LAN cable is further improved. The foaming degree of polyethylene is preferably 15% or more. When the foaming degree of polyethylene is 15% or more, the flame retardancy of the LAN cable is further improved.

4). Intermediate layer The intermediate layer is provided between the sheath and the electric wire. The intermediate layer has a mass reduction rate at 500 ° C. of 10% by mass or less and a mass reduction rate at 600 ° C. of 50% by mass or less. The mass reduction rate of the intermediate layer is a value measured using a differential scanning calorimeter (DSC) in a dry air atmosphere at a temperature rising rate of 10 ° C./min. By providing the intermediate layer having the above characteristics, the flame resistance of the LAN cable is further improved.

  Examples of the material for the intermediate layer include metals and organic substances. If an organic material is used as the material of the intermediate layer, the flexibility of the LAN cable can be further improved. Examples of the organic substance include polyimide and mica, but polyimide is preferable. When the intermediate layer includes polyimide, the flexibility of the LAN cable is further improved.

The position of the intermediate layer in the LAN cable can be selected as appropriate, but the position immediately below the sheath is preferable. When it is directly under the sheath, the intermediate layer hardly affects the dielectric characteristics.
As a form of an intermediate | middle layer, the form comprised by winding a film is mentioned, for example. A plurality of films may be wound around a plurality of places to form the intermediate layer. Although how to wind a film is not specifically limited, For example, a horizontal winding, vertical attachment, etc. are mentioned. By making the film wound sideways, the flexibility of the LAN cable can be further improved. In the case of horizontal winding, for example, the film can be wound while wrapping a part having a specified width. The amount of wrap is preferably ¼ wrap or more.
<Example>
(1) Manufacture of LAN cable 1 The LAN cable 1 having the configuration shown in FIG. 1 was manufactured. The LAN cable 1 includes a sheath 3, an electric wire 5, an intermediate layer 7, an aluminum laminated PET tape 9, and a copper braid 11. The electric wire 5 is accommodated in the sheath 3. The electric wire 5 includes a tin-plated copper conductor 13 located at the center thereof, and an insulator 15 located on the outer periphery of the tin-plated copper conductor 13. That is, the electric wire 5 is covered with the insulator 15. The intermediate layer 7 is located between the sheath 3 and the electric wire 5. The aluminum laminated PET tape 9 and the copper braid 11 are located between the electric wire 5 and the intermediate layer 7.

  The manufacturing method of the LAN cable 1 is as follows. First, an insulator and a sheath material were prepared. The composition of the insulator material and the sheath material is shown in Tables 1 to 3, respectively. The unit of the compounding amount in Tables 1 to 3 is parts by mass.

In these blends, pellets formed by kneading with a pressure kneader at a start temperature of 40 ° C. and an end temperature of 190 ° C. were used as insulator and sheath materials.
Next, the tin-plated copper conductor 13 having an outer diameter of 0.78 mm was coated with the above-described insulator material at a thickness of 0.4 mm and cross-linked with an irradiation amount of 7 MRad to manufacture the electric wire 5.

  Next, the aluminum laminated PET tape 9 was wound with 1/4 wrap around the wire 5 that was combined from four pairs. Next, the copper braid 11 was covered. Next, the intermediate layer 7 was formed by horizontally winding a polyimide tape with 1/4 wrap. Next, the above-mentioned sheath material was coated with a thickness of 1.1 mm, and was subjected to irradiation crosslinking with an irradiation amount of 13 MRad to manufacture a LAN cable 1.

  However, in R2 shown in Table 3, the intermediate layer 7 was not formed. In R4, a PET film was used instead of the polyimide tape.

  The manufactured LAN cable 1 includes S1 to S10 and R1 to R4 shown in Tables 1 to 3 above. Tables 1 to 3 show the composition of the insulator 15, the composition of the sheath 3, the type of film, and the number of films in each LAN cable 1. The mass reduction rate at 500 ° C. of the polyimide films shown in Tables 1 to 3 is 1% by mass, and the mass reduction rate at 600 ° C. is 26% by mass. Moreover, the mass reduction rate in 500 degreeC of the PET film shown in Table 3 is 100 mass%, and the mass reduction rate in 600 degreeC is 100 mass%.

  The polyimide films in Tables 1 to 3 are Kapton 200H (manufactured by Toray DuPont). The maleic acid-modified polyolefin A in Tables 1 to 3 is Toughma MH7020 (manufactured by Mitsui Chemicals). Magnesium hydroxide (part 1) in Tables 1 to 3 is Magnifine H10A (manufactured by Albemarle). Magnesium hydroxide (No. 2) in Tables 1 to 3 is Magnifine H10C (manufactured by Albemarle).

(2) Test of sheath characteristics The following tests were performed for each of S1 to S10 and R1 to R4.
(2-1) Sheath tensile test Only the sheath was peeled from the LAN cable and punched into a No. 6 dumbbell test piece. Next, using the test piece, a tensile test was performed in accordance with JIS C 3005 under the condition of a tensile speed of 200 mm / min. About elongation, when elongation was less than 125%, it was set as x (failure), and when elongation was 125% or more, it was set as o (pass).

Moreover, about tensile strength, when tensile strength was less than 10 MPa, it was set as x (failed), and when it was 10 MPa or more, it was set as (good) with a tolerance. The test results are shown in Tables 1 to 3.
(2-2) Low temperature test of sheath The test piece was the same as in the tensile test. Using the test piece, a tensile test was performed at −55 ° C. under the condition of a tensile speed of 25 mm / min in accordance with EN60811-1-4. When the elongation characteristic was 30% or more, it was evaluated as “good” (accepted), and when it was less than 30%, it was evaluated as “x” (failed). The test results are shown in Tables 1 to 3.

(3) Test of LAN cable characteristics The following tests were performed for each of S1 to S10 and R1 to R4.
(3-1) LAN cable low temperature test
In accordance with EN60811-1-4 8.1, the LAN cable was subjected to a bending test at −55 ° C. When the crack did not occur after winding, it was evaluated as “◯” (accepted), and when the crack occurred, it was determined as “x” (failed). The test results are shown in Tables 1 to 3.

(3-2) Flame resistance test of LAN cable
A VTFT test was performed in accordance with IEEE standard 1202. If the damage distance of the LAN cable is 1.5 m or less and is greater than 1.0 m, it is judged as ◯ (passed), if it is 1.0 m or less, ◎ (passed with a margin), and larger than 1.5 m X (failed). The test results are shown in Tables 1 to 3.

(3-3) LAN cable transmission characteristics test
The capacitance was measured in accordance with JIS X5150 and TIA-568-C, 2. When the capacitance was 5.6 nF / 100 m or less, it was evaluated as ◯ (passed), and when it was larger than 5.6 nF / 100 m, it was evaluated as x (failed). The test results are shown in Tables 1 to 3.

(4) About a test result The test result of S1-S10 was favorable also in any test item. In particular, in S2 and S3, the flame retardancy was higher due to the foaming of the insulator. Moreover, in S4, the flame retardance was higher because the number of polyimide films was two. In S5 to S7, as the amount of the flame retardant added in the sheath 3 was increased, the flame retardancy tended to be further improved.

In R1, the capacitance was large, and the test result of the transmission characteristics was x. This reason is considered to be because the dielectric constant of the insulator 15 is large. In R2, the flame retardancy test result was x. The reason is considered to be because the intermediate layer 7 is not provided. In R3, the flame retardancy test result was x. The reason for this is considered to be because the amount of flame retardant added is small. In R4, the flame retardancy test result was x. This reason is considered to be because the mass reduction rate of the PET film used for forming the intermediate layer 7 is large.
<Other embodiments>
As mentioned above, although embodiment of this indication was described, this indication is not limited to the above-mentioned embodiment, and can carry out various modifications.

(1) The form of the LAN cable may be, for example, a two-core insulator structure or another structure.
(2) A function of one component in each of the above embodiments may be shared by a plurality of components, or a function of a plurality of components may be exhibited by one component. Moreover, you may abbreviate | omit a part of structure of each said embodiment. In addition, at least a part of the configuration of each of the above embodiments may be added to or replaced with the configuration of the other above embodiments. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure.

  (3) In addition to the LAN cable described above, the present disclosure can be realized in various forms such as a method for manufacturing the LAN cable.

DESCRIPTION OF SYMBOLS 1 ... LAN cable, 3 ... Sheath, 5 ... Electric wire, 7 ... Intermediate layer, 9 ... Aluminum laminated PET tape, 11 ... Copper braid, 13 ... Tin plating copper conductor, 15 ... Insulator

Claims (3)

Sheath,
An electric wire housed in the sheath and covered with an insulator;
A LAN cable comprising:
Between the sheath and the electric wire, further comprising an intermediate layer having a mass reduction rate at 500 ° C. of 10% by mass or less and a mass reduction rate at 600 ° C. of 50% by mass or less,
The insulator includes polyethylene having a dielectric constant of 2.5 or less,
The sheath is a LAN cable containing 150 parts by mass or more of a flame retardant with respect to 100 parts by mass of a polyolefin-based polymer. The LAN cable according to claim 1,
The foaming degree of the polyethylene contained in the insulator is 15% or more,
The flame retardant is a LAN cable containing magnesium hydroxide and / or aluminum hydroxide. The LAN cable according to claim 1 or 2,
The intermediate layer is a LAN cable containing polyimide.

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