JP5425973B2 - Heat resistant flame retardant insulated wire - Google Patents

Description

  The present invention relates to an insulated wire excellent in heat resistance, flame retardancy, and workability.

  Recently, there is an increasing need for insulated wires that have both heat resistance and flame resistance in applications such as gas appliances and motor wires for microwave ovens. Specifically, it is an insulated wire having a heat resistance of 130 to 150 ° C. based on a technical standard of electrical appliances and a flame retardancy that passes a UL vertical combustion test (VW-1).

  As this type of insulated wire, for example, an insulated wire using a composition in which a specific flame retardant is combined with an ethylene copolymer as a coating material is known (see, for example, Patent Document 1). However, it does not have characteristics that sufficiently satisfy the above requirements.

  On the other hand, an electric wire using a fluoro rubber typified by a tetrafluoroethylene-propylene copolymer as an insulating material is known. Fluororubber is excellent in heat resistance, oil resistance, chemical resistance, aging resistance, weather resistance, electrical insulation, and the like, and an electric wire using this has high heat resistance.

  However, fluororubber has strong adhesiveness in an uncrosslinked state, and there is a possibility that the shape of the coating may change or the appearance may be damaged when the coatings come into contact with each other, such as when wound on a drum in an uncrosslinked state. It was. For this reason, it is necessary to carry out the (extrusion) molding step and the crosslinking step continuously, and there is a problem in workability. In addition, since fluororubber is very expensive, it has been used for coating special wires used in harsh high-temperature environments exceeding 200 ° C, such as wiring wires around engines such as automobiles. It was limited.

JP 2007-119515 A

  The present invention has been made in response to such a conventional situation, and an object thereof is to provide an insulated wire having both heat resistance and flame retardancy, good workability, and low cost.

  The heat-resistant flame-retardant insulated wire according to the first aspect of the present invention is 100 parts by mass of a base polymer comprising (A) 50 to 90% by mass of a tetrafluoroethylene-propylene copolymer and (B) 10 to 50% by mass of a polyolefin. On the other hand, it has a coating made of an electrically insulating composition containing (C) 1 to 30 parts by mass of ethylenebis (pentabromophenyl) and (D) 10 to 50 parts by mass of antimony trioxide.

  According to a second aspect of the present invention, in the heat-resistant flame-retardant insulated wire according to the first aspect, the base polymer includes (A) a tetrafluoroethylene-propylene copolymer of 55 to 85% by mass, and (B) a polyolefin of 15 to It consists of 45 mass%.

  According to a third aspect of the present invention, in the heat-resistant flame-retardant insulated wire according to the first aspect or the second aspect, 2 to 15 parts by mass of (C) ethylenebis (pentabromophenyl) with respect to 100 parts by mass of the base polymer. And (D) 15 to 35 parts by mass of antimony trioxide.

  According to a fourth aspect of the present invention, in the heat-resistant flame-retardant insulated wire according to any one of the first to third aspects, the component (B) contains an ethylene / ethyl acrylate copolymer. .

  According to a fifth aspect of the present invention, in the heat-resistant flame-retardant insulated wire according to any one of the first to fourth aspects, (E) inorganic filler 1 is further added to 100 parts by mass of the base polymer. It contains ~ 200 parts by mass.

  According to a sixth aspect of the present invention, in the heat-resistant flame-retardant insulated wire according to the fifth aspect, the component (E) contains calcium carbonate.

  According to a seventh aspect of the present invention, in the heat-resistant flame-retardant insulated electric wire according to any one of the first to sixth aspects, the electrically insulating composition is crosslinked.

  According to an eighth aspect of the present invention, in the heat-resistant flame-retardant insulated electric wire according to any one of the first to seventh aspects, the whole electric wire is flame retardant that passes the VW-1 vertical combustion test (UL 1581). In addition, the tensile strength after thermal aging (180 ° C., 336 hours) of the coating made of the electrical insulating composition is 4.0 MPa or more and the tensile elongation is 50% or more.

  According to the heat-resistant and flame-retardant insulated wire of the present invention, it is possible to have both excellent heat resistance and flame retardancy, good workability, and low price.

It is a cross-sectional view which shows one Embodiment of the heat-resistant flame-retardant insulated wire of this invention.

  Embodiments of the present invention will be described below.

  First, the electrically insulating composition used for the heat-resistant flame-retardant insulated wire of the present invention will be described.

（式中、ｎおよびｍは、それぞれ１以上の整数を表す） The tetrafluoroethylene-propylene copolymer of the component (A) constituting the base polymer of the electrically insulating composition used in the present invention is typically a polymer having a basic skeleton represented by the following formula, It can be obtained by low-temperature emulsion polymerization of tetrafluoroethylene and propylene.

(In the formula, n and m each represent an integer of 1 or more)

  This tetrafluoroethylene-propylene copolymer contains, as a third component, a copolymerizable monomer such as ethylene, isobutylene, acrylic acid and its alkyl ester, methacrylic acid and its alkyl ester, vinyl fluoride, vinylidene fluoride, An appropriate amount of one or more of hexafluoropropene, chloroethyl vinyl ether, chlorotrifluoroethylene, perfluoroalkyl vinyl ether and the like may be contained. As the component (A), the tetrafluoroethylene-propylene copolymer may be used singly or in combination of two or more.

  Examples of commercially available tetrafluoroethylene-propylene copolymers used as the component (A) include AFLAS 150CS (specific gravity: 1.55, fluorine content: 57%, Mooney viscosity ML1 + 10 (manufactured by Asahi Glass Co., Ltd.). 100 ° C.): 140, Mooney viscosity ML1 + 10 (121 ° C.): 100), AFLAS 150C (specific gravity: 1.55, Mooney viscosity ML1 + 10 (100 ° C.):> 160), AFLAS 150E (specific gravity: 1.55, Mooney) Viscosity ML1 + 10 (100 ° C.): 60, Mooney viscosity ML1 + 10 (121 ° C.): 45) (above, trade name) and the like.

  Examples of the component (B) polyolefin used in the present invention include low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), very low density polyethylene (VLDPE), and linear low density. Polyethylene such as polyethylene (LLDPE); polypropylene (PP); polyisobutylene; ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1 Copolymerization of α-olefins such as undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicocene and 4-methyl-1-pentene Ethylene / α-olefin copolymer; Methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isobutyl acrylate, dimethyl maleate, maleate Ethylene / unsaturated carboxylic acid ester copolymer obtained by copolymerizing unsaturated carboxylic acid ester such as diethyl acid; ethylene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl persate, vinyl laurate, vinyl stearate And ethylene / vinyl ester copolymers obtained by copolymerizing vinyl esters such as vinyl benzoate, vinyl salicylate and vinyl cyclohexanecarboxylate; and isobutylene / isoprene copolymers. As the polypropylene, not only a homopolymer of propylene, but also a random copolymer or block copolymer with ethylene, a copolymer with a small amount of α-olefin, and the like can be used. Examples of the α-olefin include 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene and the like. A non-conjugated polyene may be further copolymerized with the propylene / α-olefin copolymer. Examples of the non-conjugated polyene include dicyclopentadiene, 1,4-hexadiene, ethylidene norbornene, and vinyl norbornene. These may be used individually by 1 type and may be used in combination of 2 or more type.

Among these, low-density polyethylene, linear low-density polyethylene, and ethylene / ethyl acrylate copolymer are preferable as the polyolefin, and ethylene / ethyl acrylate copolymer is more preferable from the viewpoint of excellent heat resistance. Examples of commercially available ethylene / ethyl acrylate copolymers include Lexpearl EEA A1150 (density: 0.932 g / cm ³ , MFR: 0.8 g / 10 min, manufactured by Nippon Polyethylene Co., Ltd.) Amount: 15% by mass, melting point (DSC method) 100 ° C., oxygen index 10.0;

  The mixing ratio of the component (A) and the component (B) in the base polymer of the electrically insulating composition used in the present invention is such that the tetrafluoroethylene-propylene copolymer of the component (A) is 50 to 90% by mass, (B) The component polyolefin is 10 to 50% by mass. When the proportion of the component (A) is less than 50% by mass, not only the heat resistance is lowered, but also the mechanical properties and weather resistance are lowered. Moreover, when the ratio of (A) component exceeds 90 mass%, workability will fall. In addition, the adhesiveness in an uncrosslinked state increases, and cost reduction becomes difficult. Preferably, the (A) component tetrafluoroethylene-propylene copolymer is 55 to 85% by mass, the (B) component polyolefin is 15 to 45% by mass, and more preferably, the (A) component tetrafluoroethylene- The propylene copolymer is 65 to 75% by mass, and the polyolefin (B) is 25 to 35% by mass.

Component (C), ethylene bis (pentabromophenyl), which is blended in the electrical insulating composition used in the present invention, is a compound represented by the following formula known as a brominated flame retardant. Specific examples of commercially available products that are suitably used as the component (C) include SAYTEX 8010 (trade name, manufactured by ALBEMARLE).

  The blending amount of ethylenebis (pentabromophenyl) as the component (C) is 1 to 30 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) which are constituent components of the base polymer described above. It is preferably 2 to 15 parts by mass, more preferably 3 to 7 parts by mass. When the blending amount is less than 1 part by mass, sufficient flame retardancy cannot be obtained, and when it exceeds 30 parts by mass, the mechanical properties may be deteriorated.

  In the present invention, at least one brominated flame retardant other than ethylene bis (pentabromophenyl) can be used in combination as long as the effects of the present invention are not impaired. Examples of the brominated flame retardant used in combination include ethylene bistetrabromophthalimide, decabromodiphenyl oxide, and tetradecabromodiphenoxybenzene.

  The antimony trioxide (D) compounded in the electrically insulating composition used in the present invention is a component that acts as a flame retardant aid. This antimony trioxide of component (D) is blended in an amount of 10 to 50 parts by mass with respect to 100 parts by mass of the total amount of the base polymer component described above. Preferably it is 15-35 mass parts, More preferably, it is 15-25 mass parts. When the blending amount is less than 10 parts by mass, sufficient flame retardancy cannot be obtained, and when it exceeds 50 parts by mass, mechanical properties are deteriorated.

  The electrical insulating composition used in the present invention can be blended with (E) an inorganic filler for the purpose of improving mechanical properties such as tensile strength. Examples of the inorganic filler include calcium carbonate, fused silica, crystalline silica, talc, clay, alumina, zirconia, mica, titanium white, bengara, silicon carbide, boron nitride, silicon nitride, and aluminum nitride. Of these, calcium carbonate and talc are preferable from the viewpoint of heat resistance. They also have the advantage that light color formulation is possible. As the calcium carbonate, both heavy calcium carbonate and light calcium carbonate can be used. When mix | blending an inorganic filler, the compounding quantity becomes like this. Preferably it is 1-200 mass parts with respect to 100 mass parts of total amounts of the base polymer component mentioned above, More preferably, it is 10-100 mass parts.

  In addition to the above components, the electrical insulating composition used in the present invention includes additives such as processing aids, dispersants, colorants, anti-aging agents, lubricants and the like generally blended in this type of composition. Can be blended as needed as long as the effects of the present invention are not impaired.

  For example, as a processing aid, 0.5 to 2.0 parts by mass of polyethylene wax, sodium stearate, or the like can be blended with respect to 100 parts by mass of the polymer component. Moreover, an aliphatic hydrocarbon resin mixture etc. can be mix | blended as a dispersing agent 0.5-2.0 mass parts with respect to 100 mass parts of polymer components. By blending such processing aids and dispersants, it is possible to suppress deterioration in properties such as mechanical strength and heat resistance accompanying polymer blending, and to improve workability during extrusion molding. it can. Specifically, AC-617A (trade name, manufactured by Honeywell; polyethylene wax) or the like is used as a processing aid. Further, ULTRA-LUBE 790 (trade name, manufactured by Performance Additives; fatty acid ester / special lubricant mixture) is used as a dispersant.

  Also, other flame retardants and flame retardant aids other than the brominated flame retardants and antimony trioxide described above can be blended within a range that does not impair the effects of the present invention. Examples of such flame retardants and flame retardant aids include metal hydrates such as magnesium hydroxide and aluminum hydroxide, nitrogen flame retardants such as guanidine and melamine, and phosphorus flame retardants such as ammonium phosphate and red phosphorus. Examples include flame retardants, phosphorus-nitrogen flame retardants, and boric acid compounds such as zinc borate.

  The electrically insulating composition used in the present invention is usually crosslinked after molding (coating). The crosslinking method is not particularly limited, and any method such as chemical crosslinking using a crosslinking agent or crosslinking by radiation such as an electron beam can be used. As a crosslinking agent used for chemical crosslinking, an organic peroxide is preferable. For example, 1,3-bis- (t-butylperoxyisopropyl) benzene or the like is used. Further, it is preferable to use a crosslinking aid such as triallyl isocyanurate together with such a crosslinking agent. The organic peroxide is preferably blended in an amount of 0.5 to 2.0 parts by mass with respect to 100 parts by mass of the polymer component, and the crosslinking aid is 0.5 to 100 parts by mass with respect to 100 parts by mass of the polymer component. It is preferable to blend 10.0 parts by weight.

  The electrically insulating composition comprises (A) tetrafluoroethylene-propylene copolymer, (B) polyolefin, (C) ethylenebis (pentabromophenyl) and (D) antimony trioxide as described above, and Various components to be blended accordingly can be produced by sufficiently kneading with an open roll, a Banbury mixer, a pressure kneader or the like. Additives such as component (C), component (D) and component (E), processing aids, and dispersants are mixed in advance when kneading each component (A) and component (B). Also good.

  The heat-resistant and flame-retardant insulated wire of the present invention is produced by subjecting the electrical insulating composition obtained as described above to extrusion coating on a conductor directly or through another coating and crosslinking. Since the composition has low tackiness in an uncrosslinked state, even if the coating is wound around a drum while being in an uncrosslinked state, the coatings are not strongly adhered to each other. Therefore, the crosslinking step may be performed as a separate step from the extrusion coating step, or may be performed continuously in a single step. In addition, the material of the conductor, the outer diameter, the presence or absence of twisting, and the like are not particularly limited, and are appropriately selected depending on the application.

  FIG. 1 is a cross-sectional view showing an embodiment of the heat and flame retardant insulated wire of the present invention.

  In FIG. 1, reference numeral 11 denotes a conductor composed of one or more tin-plated annealed copper wires and the like. The conductor 11 is coated with the above-mentioned electrically insulating composition by extrusion coating and crosslinked to form an insulator. 12 is formed.

It is preferable that the insulated wire of this embodiment is comprised so that the following requirements may be satisfied.
(1) As a whole electric wire, it has flame retardancy that passes the VW-1 vertical combustion test (UL 1581).
(2) The tensile strength after thermal aging (180 ° C., 336 hours) of the insulator 12 is 4.0 MPa or more, and the tensile elongation is 50% or more. The tensile strength and tensile elongation are values measured according to JIS C 3005.

  The insulated wire of the present embodiment can have both heat resistance of a heat resistance temperature of 130 to 150 ° C. based on the technical standards of electric appliances and flame retardance that passes the UL vertical combustion test (VW-1). In addition, the cross-linking process is not limited as in the case of electric wires using conventional fluororubber, and an increase in price is also suppressed.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all. The components used in Examples and Comparative Examples are as follows.

FEPM (tetrafluoroethylene-propylene copolymer)
Product name AFLAS 150CS manufactured by Asahi Glass Co., Ltd.
LDPE (low density polyethylene):
Product name NUC 9026 manufactured by Nippon Unicar Co., Ltd.
HDPE (high density polyethylene):
Brand name made by Prime Polymer Co., Ltd. Hi-Zex 5305E
EEA (ethylene / ethyl acrylate copolymer):
Product name Lexpearl EEA A 1150 manufactured by Nippon Polyethylene Co., Ltd.
Ethylene bis (pentabromophenyl):
Product name SAYTEX 8010 manufactured by ALBEMARLE
Heavy calcium carbonate:
Shiraishi Calcium Co., Ltd. Product name Whiteon SSB

Example 1
FEPM 50 parts by mass, LDPE 50 parts by mass, ethylene bis (pentabromophenyl) 2.0 parts by mass, antimony trioxide 30 parts by mass and heavy calcium carbonate 30 parts by mass sufficiently using an open roll to electrically insulate composition A product was prepared.

Subsequently, the above electrically insulating composition was extrusion coated to a thickness of 0.33 mm on a copper stranded wire conductor having a cross-sectional area of 0.3 mm ^{2 formed} by collectively twisting 12 tin-plated annealed copper wires having a diameter of 0.18 mm, and accelerated. An insulator was formed by irradiating an electron beam of 200 kGy with an electron beam irradiation apparatus having a voltage of 800 kV to produce an insulated wire having an outer diameter of 1.38 mm.

Examples 2-9, Comparative Examples 1-9
An electrical insulating composition was prepared in the same manner as in Example 1 except that the composition of the electrical insulating composition was changed as shown in Table 1. Further, in the same manner as in Example 1 using these compositions. Insulated wires were manufactured.

With respect to the insulated wires obtained in the above Examples and Comparative Examples, initial mechanical properties (tensile strength, elongation), heat resistance (heat aging resistance) and flame retardancy were evaluated. Separately from the insulated wire, an uncrosslinked sheet of 100 mm × 100 mm × 1 mm was prepared using the electrically insulating compositions obtained in the above examples and comparative examples. The tackiness was evaluated. The evaluation method is as follows.
[Initial tensile strength and initial tensile elongation]
Based on JIS C 3005, the measurement was performed under the conditions of a standard line of 20 mm and a tensile speed of 500 mm / min.
[Heat-resistant]
After heat aging at 180 ° C. for 336 hours, tensile strength and elongation were measured in accordance with JIS C 3005 under conditions of a standard line of 20 mm and a tensile speed of 500 mm / min.
[Flame retardance]
A vertical combustion test (VW-1) defined in UL1581 was conducted and evaluated.
[Adhesiveness when not cross-linked]
Two uncrosslinked sheets were stacked, 500 g was uniformly loaded, and left in a thermostatic bath at 50 ° C. for 1 hour. After leaving it, it was taken out from the thermostat and cooled to room temperature, and the two sheets were peeled off. About each sheet after peeling, the length of the diagonal of a 100 mm x 100 mm surface was measured, the average value was calculated, the rate of change from an initial value was calculated | required, and the following reference | standard evaluated.
◎: Diagonal length change rate 7% or less, no tearing or tearing ○: Diagonal length change rate 10% or less, no tearing or tearing,
×: Diagonal length change over 10%, or tear or tear

  These results are shown in Table 1.

  As is clear from Table 1, all of Examples 1 to 9 gave good results in initial tensile strength, initial tensile elongation, heat resistance, vertical combustion test, and tackiness during uncrosslinking. Further, by setting the content of tetrafluoroethylene-propylene copolymer in the base polymer to 55 to 85% by mass and the content of polyolefin to 15 to 45% by mass, the initial tensile strength and initial tensile elongation are even better. Results were obtained (Examples 4-7). Furthermore, by setting the content of ethylenebis (pentabromophenyl) to 2 to 15 parts by mass and the content of antimony trioxide to 15 to 35 parts by mass with respect to 100 parts by mass of the base polymer, heat resistance and adhesion at the time of non-crosslinking Even better results were obtained in Examples (Examples 5 and 6).

  11 ... conductor, 12 ... insulator.

Claims (8)

  (C) ethylenebis (pentabromophenyl) 1-30 with respect to 100 parts by mass of a base polymer composed of 50-90% by mass of (A) tetrafluoroethylene-propylene copolymer and 10-50% by mass of (B) polyolefin. A heat-resistant and flame-retardant insulated electric wire having a coating made of an electrically insulating composition containing 10 parts by mass of (D) antimony trioxide (D).   2. The heat-resistant and flame-retardant insulated wire according to claim 1, wherein the base polymer comprises (A) a tetrafluoroethylene-propylene copolymer of 55 to 85% by mass and (B) a polyolefin of 15 to 45% by mass.   3. The base polymer contains (C) 2 to 15 parts by mass of ethylene bis (pentabromophenyl) and (D) 15 to 35 parts by mass of antimony trioxide with respect to 100 parts by mass of the base polymer. The heat-resistant and flame-retardant insulated wire described.   The heat-resistant flame-retardant insulated wire according to any one of claims 1 to 3, wherein the component (B) contains an ethylene / ethyl acrylate copolymer.   5. The heat-resistant and flame-retardant insulated wire according to claim 1, further comprising (E) 1 to 200 parts by mass of an inorganic filler with respect to 100 parts by mass of the base polymer.   The heat-resistant flame-retardant insulated wire according to claim 5, wherein the component (E) contains calcium carbonate.   The heat-resistant flame-retardant insulated wire according to any one of claims 1 to 5, wherein the electrically insulating composition is crosslinked.   The wire as a whole has flame retardancy that passes the VW-1 vertical combustion test (UL 1581) and has a tensile strength of 4 after heat aging (180 ° C., 336 hours) of the coating made of the electrically insulating composition. The heat-resistant flame-retardant insulated electric wire according to any one of claims 1 to 7, wherein the tensile elongation is 50% or more at 0.0 MPa or more.

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