JP2002324442A - Halogen-free flame-retardant electric wire/cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a halogen-free flame-retardant electric wire/cable excellent in durability against corrosive gases such as NOX and SOX. SOLUTION: In the halogen-free flame-retardant electric wire/cable, a plurality of conductors 1 each covered with an insulator 2, are assembled under the presence of a medium 4, covered further with a sheath 3, the sheath 3 is composed of a composition obtained by combining not more than 300 pts.wt. of halogen-free flame-retardant agent per rubber or plastics of 100 pts.wt., with addition of a hindered phenolic antioxidant and thioether-based antioxidant of 0.1-10 pts.wt. respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to environmental resistance, particularly to ozone, nitrogen oxides (NO _x ) and sulfur oxides (SO _x ).
The present invention relates to halogen-free flame-retardant wires and cables having excellent durability against corrosive gases such as.

[0002]

2. Description of the Related Art In recent years, non-halogen flame-retardant electric wires and cables which do not use polyvinyl chloride or halogen-based flame retardants and have a small environmental load have rapidly spread as so-called eco-electric wires and cables. These non-halogen flame retardant wires
As the cable, a resin composition in which a polyolefin is mixed with a large amount of a non-halogen flame retardant such as magnesium hydroxide as an insulator of a wire or a sheath of the cable is generally used.

However, according to the conventional halogen-free flame-retardant electric wires and cables using a resin composition containing a large amount of a non-halogen flame-retardant mixed therein, the electric contacts of a switchboard, a substation room, etc. When wired in an existing enclosed space, when used as a lead wire, or when used for automobiles and vehicles, locally high NO
_x, when exposed to a corrosive gas such as SO _x, occurs tackiness on the surface of the humid environment wire and cable, also has a problem that the hot and humid environment condensation occurs. this is,
This is because magnesium hydroxide reacts with corrosive gas such as NO _x and SO _x to generate magnesium nitrate and magnesium sulfate, which absorb sticky water and dew due to absorbing moisture in the air.

Further, when the surface of the electric wire / cable is dried, there is a problem that generated crystals of magnesium nitrate or magnesium sulfate remain on the surface to cause deterioration of the appearance of the electric wire / cable.

Accordingly, an object of the present invention is to provide NO _x , S
And to provide an excellent non-halogen flame retardant wire and cable durability against corrosive gases O _x or the like.

[0005]

According to the present invention, there is provided a non-halogen flame-retardant electric wire or cable in which an insulator or a sheath contains a non-halogen flame retardant. Or a composition in which 300 parts by weight or less of a halogen-free flame retardant is mixed with 100 parts by weight of a plastic, and 0.1 to 10 parts by weight of a hindered phenol-based antioxidant and 0.1 to 10 parts by weight of a thioether-based antioxidant are added. Halogen-free flame-retardant electric wires and cables. Such an insulator or a sheath has excellent durability in continuous use in a special environment where corrosive gas such as NO _x and SO _x is present, and has extremely high reliability.

[0006] Non-halogen flame retardants include metal hydroxides, metal oxide compounds, phosphorus compounds, silicone compounds,
It is characterized in that it is a combination of one or two compounds selected from a boric acid compound, a nitrogen compound, expandable graphite, and an intemescent flame retardant.

[0007]

FIG. 1 is a diagram showing a cable according to an embodiment of the present invention. A plurality of conductors 1 covered with an insulator 2 in the presence of an interposition 6 are covered with a sheath 3.

The sheath is formed by extruding a composition obtained by adding 0.1 to 10 parts by weight of a hindered phenol antioxidant and a thioether antioxidant to a non-halogen flame-retardant material obtained by mixing rubber or plastic with magnesium hydroxide. It is formed by molding.

The rubber and plastic used for the non-halogen flame-retardant electric wire / cable of the present invention include all those containing no halogen substance in the polymer. Examples of the rubber-based material include natural rubber, styrene-butadiene rubber,
Butadiene acrylonitrile copolymer, silicone rubber, acrylic rubber and the like. Examples of the plastic material include polyolefins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and linear ultra-low-density polyethylene (VLD).
PE), high density polyethylene (HDPE), ethylene-
Methyl methacrylate copolymer (EMMA), ethylene-methyl acrylate copolymer (EMA), ethylene-
Ethyl acrylate copolymer (EEA), ethylene-vinyl acetate copolymer (EVA), ethylene-glycidyl methacrylate copolymer, ethylene-butene-1 copolymer, ethylene-butene-hexene terpolymer, ethylene- Propylene-diene terpolymer (EPDM), ethylene-octene copolymer (EOR), ethylene copolymerized polypropylene, ethylene-propylene copolymer (EP
R), poly-4-methyl-pentene-1, maleic acid-grafted low-density polyethylene, hydrogenated styrene-butadiene copolymer (H-SBR), maleic acid-grafted linear low-density polyethylene, ethylene and carbon number 4 Copolymer with α-olefin, maleic acid-grafted ethylene-methyl acrylate copolymer, maleic acid-grafted ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-ethyl acrylate-maleic anhydride Terpolymer, ethylene-propylene-butene-1 terpolymer having butene-1 as a main component, butene-
Ethylene-propylene-butene-1 terpolymer containing 1 as a main component, and further any of polypropylene, for example, isotactic polypropylene or syndiotactic polypropylene, homopolypropylene, or random polypropylene containing an ethylene-based copolymer component. it can.

Further, thermoplastic elastomers, that is, styrene-based, ester-based, urethane-based, amide-based, and olefin-based thermoplastic elastomers can also be used.

The styrene-based thermoplastic elastomer is a styrene-based block copolymer, and SBS (PS (polystyrene) -polybutadiene-PS) or SIS (PS-polyisoprene-P), depending on the type of soft segment.
S), SEBS (PS-polyethylene / butylene-P
S) and the like. Also, blends of these styrene-based block copolymers and polypropylene (PP) are included.

The ester-based thermoplastic elastomer has a hard segment of polybutylene terephthalate (PB).
T), a general term for polyethylene terephthalate (PET) having a soft polyester copolymer as a soft segment, wherein the soft segment is a polyether-ester copolymer comprising a condensate of polytetramethylene glycol (PTMG) and terephthalic acid And polyester-ester copolymers using polycaprolactone.

The hard segment of the urethane-based thermoplastic elastomer is polyurethane, and there are polyester-based and polyether-based depending on the type of the soft segment.
Further, the polyester type includes a caprolactone type, an adipate type, and a polycarbonate type.

The amide-based thermoplastic elastomer is a thermoplastic elastomer having a hard segment of nylon 6, nylon 66, nylon 11, nylon 12, or the like, and a soft segment of polyether or polyester.

[0015] The olefin-based thermoplastic elastomer is a thermoplastic elastomer having a polyolefin resin as a hard segment, and is classified into a blend type and a copolymer type. Here, the hard segment refers to the polymer component of the composition in the range of 15 to 95% by weight.

As the hard segment, crystalline polyolefin is required, and polypropylene (PP) or high-density polyethylene (HDPE) or low-density polyethylene (LDPE), linear low-density polyethylene (LL)
DPE). As the soft segment, ethylene-propylene copolymer (EPM), ethylene-propylene-diene terpolymer (EPDM), acrylonitrile-butadiene copolymer (NBR), hydrogenated NBR, ethylene-octene copolymer ( EOR),
Ethylene-butene-1 copolymer (EBR), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), ethylene-ethyl acrylate copolymer (EEA), ethylene-vinyl acetate copolymer (EV
A) and an elastomer containing a styrene component.

The soft segment may be partially crosslinked with an organic peroxide or the like, or the soft segment dispersed at the time of kneading may be completely crosslinked (dynamic vulcanization).

Examples of engineering plastics include polyamide, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, modified polyphenylene oxide, polyetherimide, polyamideimide, polyphenylene sulfide, polyether sulfone, polyether ether ketone, and polyether ketone. Flexible polyamide 46, polyamide 610, polyamide 612, polyamide 11,
There are polyamide 12, polybutylene terephthalate, polyphenylene oxide modified with a styrene-based block copolymer, polyetherimide, and polyetheretherketone.

Magnesium hydroxide (Mg (OH) ₂ ) used as the non-halogen flame retardant used in the present invention is a solid solution of synthetic magnesium hydroxide, natural magnesium hydroxide obtained by pulverizing natural ore, and a solid solution with other elements such as nickel and zinc. And the like. The reason why the mixing amount of magnesium hydroxide is specified to be 300 parts by weight or less with respect to 100 parts by weight of the resin is that if it exceeds 300 parts by weight, the mechanical properties are significantly reduced. It is more preferable that the magnesium hydroxide has an average particle diameter of 10 μm or more and a coarse particle content of 10% or less measured by a laser particle size distribution meter in terms of mechanical strength, dispersibility, and flame retardancy. In consideration of water resistance, the surface of these particles can be surface-treated with a fatty acid, a fatty acid metal salt, a silane-based coupling agent, a titanate-based coupling agent or an acrylic resin or a phenol resin according to a conventional method.

The hindered phenolic antioxidants used in the present invention include 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane,
4,4'-butylidenebis- (3-methyl-6-tert-butylphenol), 2,2thiobis (4-methyl-6-
Tert-butylphenol), n-octadecyl-3-
(4'-hydroxy-3 ', 5'-di-tert-butylphenyl) propionate, tetrakis- (methylene-3-
(3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate) methane, triethylene glycol-bis- (3- (3-tert-butyl-5-methyl-4-)
(Hydroxyphenyl) propionate), 6- (4-hydroxy-3,5-di-tert-butylanilino) -2,4
-Bis-octyl-thio-1,3,5-triazine, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate, A: bis (3,5-di-tert-butyl) Ethyl 4-hydroxybenzylphosphonate)
Calcium, B: polyethylene wax (50%),
3,5-di-tert-butyl-4-hydroxybenzyl-phosphonate-diethyl ester, hindered phenol, hindered bisphenol and the like.

Examples of the thioether antioxidants include dilauryl-thiodipropionate, distearyl-thiodipropionate, dimyristyl-3,3'-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl- Thiopropionate), dilauryl thiodipropionate, β-alkylthioester-propionate, sulfur-containing ester compounds, 1,1′-thiobis (2-naphthol) and the like.

The amount of each of the hindered phenol antioxidant and the thioether antioxidant is 0.1%.
The reason for limiting to 10 to 10 parts by weight is that if it is less than 0.1 part by weight, the effect of preventing oxidation is low, and if it exceeds 10 parts by weight, flame retardancy is reduced and bleeding occurs.

In the present invention, in addition to magnesium hydroxide as a non-halogen flame retardant, for example, metal hydroxide,
Metal oxide compounds, phosphorus compounds, silicone compounds, boric acid compounds, nitrogen compounds, expandable graphite, intemescent flame retardants, and the like may be used.

Examples of the metal hydroxide-based flame retardant include aluminum hydroxide (Al (OH) ₃ ), hydrotalcite, calcium aluminate hydrate, calcium hydroxide, barium hydroxide, and hard clay. .

Examples of the metal oxide compound include magnesium oxide, antimony oxide, and aluminum oxide.

Examples of the phosphorus compound include red phosphorus, phosphate ester, phosphonate, phospholinene, ammonium polyphosphate and the like. In particular, the addition of red phosphorus is highly effective in improving flame retardancy.

Examples of the silicone compound include silicone gum, silicone powder, silicone oil, silicone-grafted polyolefin, and composite rubber of polyorganosiloxane and acrylic rubber.

Examples of the silicone compound include silicone gum, silicone powder, silicone oil, silicone-grafted polyolefin, and a composite rubber of polyorganosiloxane and acrylic rubber.

Examples of the boric acid compound include zinc borate, calcium borate, barium borate, barium metaborate and the like. Examples of the nitrogen-based flame retardant include guanidine sulfamate and melamine cyanurate. The intumescent flame retardant is a flame retardant composed of a mixture of a component that foams and a component that solidifies during combustion. Examples of the foaming component include a nitrogen-based foaming agent, and those having a high decomposition temperature (300 ° C. or higher) such as a tetrazole compound are preferable. As a solidifying component, the above phosphorus-based, silicone-based, boric-acid-based, nitrogen-based flame retardants, polyhydric alcohols such as pentaerythritol, carbon black, silica, zinc, zinc stannate, intercalated silicone-inserted clay, inorganic or organic pigments And the like.

In addition to the above materials, a filler may be added. Examples of the filler include calcium carbonate, soft clay, hard clay, calcined clay, silica, zinc oxide, mica powder, molybdenum disulfide, glass fiber, glass beads, graphite, and carbon black. Among them, calcium carbonate which is easy to knead into the resin and has little decrease in mechanical properties is preferable. Calcium carbonate includes synthetic calcium carbonate (light calcium carbonate) having small particles and heavy calcium carbonate obtained by mechanically pulverizing coarse limestone. Heavy calcium carbonate having good kneading processability is more preferable.

In consideration of water resistance, the above various compounding agents are used in accordance with a conventional method in consideration of water resistance, fatty acid metal salt, silane coupling agent, titanate coupling agent or acrylic resin,
Surface treatment with a phenolic resin is also possible.

[0032] These resin compositions may contain, if necessary, an antioxidant, a lubricant, a surfactant, a softener, a plasticizer, an inorganic filler, a compatibilizer, a stabilizer, a crosslinking agent, an ultraviolet absorber,
Additives such as light stabilizers and colorants can be added.

[0033]

EXAMPLES A resin composition, electric wires and cables were produced in the following manner. Various resin compositions were preheated to 150 ° C. 7
The mixture was kneaded and pelletized by a 6 mm twin-screw kneader (manufactured by Kobe Steel). The pellets were press-molded to obtain various test samples.
The pellet was used as a material for producing a cable.

The electric wire was produced in the following manner. The non-halogen resin composition shown in Table 1 was extruded from a 2 mm ² copper stranded circular compression conductor using a 90 mm extruder to prepare an electric wire. Table 1 shows the evaluation results of Examples 1 to 6 and Comparative Examples 1 to 4 manufactured using the materials of Table 1.

The cable was manufactured in the following manner. 2 above
A non-halogen resin composition shown in Table 1 was placed on a core obtained by twisting an electric wire having a diameter of ² mm with a polypropylene and a twist.
It was extruded as a sheath using a mm extruder to prepare a cable. Table 1 shows the evaluation results of Examples 7 to 9 and Comparative Examples 5 to 7 manufactured using the materials of Table 1.

[Table 1]

The evaluation of the electric wire or cable was performed by the following method.

(1) Corrosion-resistant gas test The prepared electric wires and cables were put in a desiccator,
Under a condition of a humidity of 50% RH, a 500 ppm nitrogen dioxide (NO ₂ ) gas was exposed for 7 days. Thereafter, the cable was left in a constant temperature / humidity bath at 40 ° C. and 90% RH for 1 hour, and then the electric wires and the surface of the cable were visually observed. A sample in which dew was not observed on the surface was evaluated as excellent, a sample in which dew was slightly observed was evaluated as good, and a sample in which dew was observed was determined as unacceptable.

(2) Quantitative Analysis of Magnesium Ions In order to confirm the relationship between surface condensation and the amount of ionic substances produced by the attack of magnesium compounds by high-concentration corrosive gases, the amount of magnesium ions on the surface was determined. did. Deposits on the surface of the sheath having a fixed area cut off from the cable sheath were wiped off with gauze thoroughly washed with pure water.
Put the gauze with the adhering substance wiped off in a beaker, and add
ml was added. After filtration with a filter, the volume was adjusted to 100 ml to obtain an analysis sample. Quantitative magnesium analysis was performed using a plasma inductively coupled (ICP) emission spectrometer (Hitachi, Model P-4000).

(3) Flame Retardancy The produced electric wire or cable was subjected to a 60 ° inclined combustion test according to JIS C 3005. The flame spread time after removing the flame was measured. Of the five tests, the one with the longest flame spread time was taken as the measured value, and the one that extinguished in less than 15 seconds was excellent,
Good for 15 seconds or more and less than 60 seconds, and bad for 60 seconds or more.

As is clear from Table 1, Examples 1 to 6 of the electric wire using the antioxidant system according to the present invention and Examples 7 to 9 of the cable have a trace amount of magnesium ion formed on the surface. It was not detected at all, and the degree of condensation on the surface was very small or no condensation was formed.

On the other hand, in Comparative Examples 1 to 3 of the electric wire and Comparative Examples 5 to 7 of the cable, a large amount of magnesium ions was generated on the surfaces of the electric wire and the cable by the corrosive gas, which resulted in significant surface dew condensation. In Comparative Example 4 of the electric wire, the flame retardancy was significantly reduced because the antioxidant exceeded the specified amount.

[0042]

As described above, according to the present invention,
The wire insulation or cable sheath must be
300 parts by weight or less for 100 parts by weight of plastic
Hindered phenol-based oxidation mixed with halogen flame retardant
Antioxidant and thioether-based antioxidant in an amount of 0.1 to 1 respectively.
0% by weight of the composition, NO_x, SO
_xContinuous use in a special environment where corrosive gases exist.
Highly durable and extremely reliable non-halogen resistant
Flammable wires and cables were obtained.

Accordingly, when the electric wire / cable according to the present invention is wired in a closed space where electric contacts are present, particularly in a switchboard, a substation room, or the like, when used as a lead wire, or when used in an automobile / vehicle. as such, are suitable for use when there is a risk to be exposed to locally high concentrations of NO _x, corrosive gases such as sO _x.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cable according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor 2 Insulator 3 Sheath 4 Interposition

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 101/00 H01B 3/00 A H01B 3/00 3/28 3/28 3/44 F 3/44 G MP 7 / 34B (72) Inventor Keisuke Sugita 5-1-1 Hidakacho, Hitachi City, Ibaraki Prefecture Within Hitachi Cable, Ltd. (72) Inventor Kiyoshi Watanabe 5-chome Hidakacho, Hitachi City, Ibaraki Prefecture No. 1-1 F-term in Hitachi Cable, Ltd. Research Institute of Technology (reference) 4J002 BB031 BB061 BB071 BB091 BB121 BB151 BP011 CF061 CF071 CK021 CL001 DE076 DE126 DE146 DK006 EJ047 EJ067 EU186 EV048 EV058 EV257 EV266 EW046 FD0A 136 CB01 CB02 CB03 CB06 CB17 CB24 CB28 CB30 CB38 5G305 AA02 AB25 BA15 CA01 CA47 CB23 CB24 CB26 CC02 CC03 CC04 CC20 CD09 DA23 5G315 CA03 CB02 CB06 CC08 CD02 CD13 CD14 CD17

Claims (2)

[Claims] 1. A non-halogen flame-retardant wire / cable having an insulator or sheath containing a halogen-free flame retardant, wherein the insulator or the sheath contains not more than 300 parts by weight of a non-halogen flame retardant per 100 parts by weight of rubber or plastic. A non-halogen flame-retardant electric wire / cable, which is a composition containing 0.1 to 10 parts by weight of a hindered phenol-based antioxidant and a thioether-based antioxidant. 2. The non-halogen flame retardant comprises a metal hydroxide, a metal oxide compound, a phosphorus compound, a silicone compound,
The non-halogen flame-retardant electric wire / cable according to claim 1, wherein the compound is a combination of one or two compounds selected from a boric acid compound, a nitrogen compound, expandable graphite, and an intemescent flame retardant. .