JP2019070065A - Flame-retardant anti-termite composition, power cable, and method of manufacturing the same - Google Patents

Abstract

To provide a flame-retardant anti-termite composition which is excellent in flame retardancy, anti-termite properties, cold resistance and extrusion processability and allows a power cable to be inexpensively manufactured, and to provide a power cable and a method of manufacturing the power cable.SOLUTION: The flame-retardant anti-termite composition contains at least polyvinyl chloride, an isocyanurate compound and a boron-based compound. The content of the isocyanurate compound is 0.05-10 pts.mass and the content of the boron-based compound is 10-55 pts.mass based on 100 pts.mass of the polyvinyl chloride. The power cable and the method of manufacturing the power cable are also provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flame retardant termite composition, a power cable and a method of manufacturing the same.

In cables such as power cables and communication cables, a protective outer coating (hereinafter referred to as a sheath) is provided on the outermost layer, and generally, a general-purpose resin such as polyethylene or polyvinyl chloride (PVC) is extrusion coated.
The sheath is required to have various functions depending on the location of the cable. For example, in the case of laying a cable in the ground of an area where activity of termites is active, a sheath which is resistant to food poisoning from termites and has a flame retardancy is required.
For this reason, it is customary to use a two-layer structure in which the sheath is not a single layer, but PVC having excellent flame retardant properties and nylon having excellent termiticidal properties are sequentially laminated or PVC, nylon, and PVC laminated in order. The

For example, in Patent Document 1, the sheath has a double structure in which an ant-proof layer is laminated on a flame-retardant layer, a flame-retardant vinyl layer is used as a flame-retardant layer, and polypropylene (PP) is laminated instead of nylon as an ant-proof layer. A wire cable having a sheath having a flame retardancy and ant-proof property has been reported by adopting a dual structure.
Also, it has been proposed to use an isocyanurate compound such as triallyl isocyanurate as an anticide (see, for example, Patent Document 2). Among these, triallyl isocyanurate having three polymerizable allyl groups is also a crosslinking aid (see Patent Document 3).

  As a sheath, a laminated structure of 2 to 3 layers results in an increase in the cable outer diameter, and in addition, different materials are laminated, so that the material cost and the manufacturing cost become high. Can be mentioned.

JP, 2015-096583, A Unexamined-Japanese-Patent No. 2-78110 Unexamined-Japanese-Patent No. 2003-192865

In the conventional electric wire cable as reported in Patent Document 1 (for example, see FIG. 2), although the sheath has a two-layer structure and there is a problem that the manufacturing cost becomes high as described above, the flame retardance It was not possible to make the sheath into a single layer, as there was no material that highly satisfied both the ant and ant resistance.
On the other hand, in the study of the present inventors, when a compound of PVC and triallyl isocyanurate is prepared and extrusion is carried out at 190 ° C., white smoke and organic compound odor are generated when the compounding amount of triallyl isocyanurate is increased. I understood it. For this reason, in the case of extrusion processing, it has been found that the installation of a local draft or the like is necessary, and there is a new problem that it leads to an increase in manufacturing cost.
In addition to flame retardancy and ant resistance, power cables also need to meet the requirements for cold resistance.

  In view of such circumstances, the present invention provides a flame retardant ant composition which is excellent in flame retardancy, termitability and cold resistance, moreover, excellent in extrusion processability and capable of producing a power cable at low cost, It is an object of the present invention to provide a power cable used and a method of manufacturing the power cable.

The present inventors use polyvinyl chloride (PVC) as a base resin of the flame retardant / antitermitative composition because of excellent flame retardancy, and extrudability by a compound of PVC and triallyl isocyanurate, In order to highly satisfy the basic performance for flame-retardant, termit-proof and cold-resistant power cables, we have studied intensively.
As a result, it has been found that a flame retardant and ant composition which highly satisfies flame resistance, ant resistance and cold resistance while satisfying extrusion processability, thereby making the sheath of the power cable into one layer. It turns out that there is an invention, resulting in the present invention.
That is, the above-mentioned subject of the present invention is achieved by the following means.

(1) A flame retardant and ant composition comprising at least polyvinyl chloride, an isocyanurate compound and a boron compound, respectively.
The content of the isocyanurate compound is 0.05 to 10 parts by mass, and the content of the boron compound is 10 to 55 parts by mass with respect to 100 parts by mass of the polyvinyl chloride. Anticide composition.
(2) The content of the isocyanurate compound is 0.05 to 0.6 parts by mass, and the content of the boron compound is 10 to 20 parts by mass with respect to 100 parts by mass of the polyvinyl chloride The flame-retardant termite composition as described in (1), characterized by the above.
(3) The flame-retardant and anti-termite composition as described in (1) or (2) used for the sheath which is the outermost layer of a power cable.
(4) A power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shield layer and a sheath are laminated in this order on a conductor,
A power cable, wherein the sheath is made of the flame-retardant and anti-termite composition according to any one of (1) to (3).
(5) The power cable according to (4), wherein the sheath has a single-layer structure.
(6) A method of manufacturing a power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shield layer and a sheath are laminated in this order on a conductor,
After sequentially laminating an inner semiconductive layer, an insulator layer, an outer semiconductive layer and a shielding layer on the conductor,
A method for producing a power cable, comprising extrusion-coating the flame-retardant and anti-termite composition according to any one of (1) to (3) onto the shielding layer.

  The flame retardant and ant composition according to the present invention are highly excellent in flame retardancy, termitability and cold resistance, moreover, excellent in extrudability, and capable of producing a power cable inexpensively, and a power cable using the same It has become possible to provide a method of manufacturing a power cable.

It is a typical sectional view showing an example of the power cable of the present invention. It is a typical sectional view showing an example of the conventional power cable.

  Hereinafter, the flame retardant and ant-proof composition of the present invention which can be preferably applied to a sheath of a power cable will be described in detail in order.

<< Flame-retardant and ant composition >>
The flame retardant termifier composition of the present invention contains at least polyvinyl chloride (PVC), an isocyanurate compound and a boron compound, respectively.
In the present invention, the content of these components in the flame retardant / antitermite composition is such that the content of the isocyanurate compound is 0.05 to 10 parts by mass with respect to 100 parts by mass of PVC, and the content of the boron compound is It is 10 to 55 parts by mass.

<Resin>
In the flame-retardant termite composition of the present invention, PVC is used as a resin component.
Among general-purpose plastics, PVC is excellent in flame retardancy, and can suppress the blending amount of materials that improve flame retardancy such as flame retardants.
If PVC is polyvinyl chloride, it may contain an average polymerization degree, a unit structure by another monomer component, and a repeating unit structure.
In the present invention, the average degree of polymerization is preferably 900 to 5,000. Also preferred is a homopolymer of vinyl chloride.
As a resin component, although other resin may be added, 80 parts by mass or more is preferable, 90 parts by mass or more is more preferable, and substantially 100 parts by mass is particularly preferable in 100 parts by mass of all resin components.

<Isocyanurate compound>
The isocyanurate compound may be any compound as long as it has an isocyanurate skeleton, but in the present invention, a compound represented by the following general formula (I) is preferable.

In formula (I), R ^{1 to} R ³ each independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group.

The aliphatic hydrocarbon group may be saturated, unsaturated or cyclic.
The aliphatic hydrocarbon group includes an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group and a cycloalkenyl group.
1-20 are preferable, as for carbon number of an aliphatic hydrocarbon group, 1-12 are more preferable, 1-8 are more preferable, and 1-6 are especially preferable.
The aliphatic hydrocarbon group is preferably an alkyl group or an alkenyl group, and more preferably an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms.
Examples of aliphatic hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, 2-ethylhexyl, decyl, vinyl, allyl, isopropenyl, ethynyl, cyclopropyl, cyclopentyl, cyclohexyl and cyclohexenyl. Be

6-20 are preferable, as for carbon number of an aryl group, 6-16 are more preferable, and 6-10 are more preferable.
The aryl group includes phenyl and naphthyl.

The hetero ring in the hetero ring group preferably has at least one atom selected from an oxygen atom, a nitrogen atom and a sulfur atom as a ring constituting atom, and it may be a saturated ring or an unsaturated ring. It may be an aromatic ring.
0-20 are preferable and, as for carbon number of such a heterocyclic group, 1-12 are more preferable.
Examples of the heterocycle of the heterocycle group include tetrahydrofuran ring, pyrrolidine ring, piperidine ring, piperidine ring, piperazine ring, furan ring, thiophene ring, pyrrole ring, imidazole ring, thiazole ring and pyridine ring.

In the compounds represented by the general formula (I), R ^{1 to} R ³ are each independently preferably a hydrogen atom or an aliphatic hydrocarbon group, and all of R ^{1 to} R ³ are more preferably an aliphatic hydrocarbon group, A group in which R ^{1 to} R ³ are all selected from an alkyl group or an alkenyl group is more preferable, and in particular, a group in which R ^{1 to} R ³ are the same is preferable.

  Among the compounds represented by the general formula (I), particularly preferred compounds are trimethyl isocyanurate, triethyl isocyanurate, tripropyl isocyanurate and triallyl isocyanurate, and triallyl isocyanurate is most preferable.

  The content of the isocyanurate compound is 0.05 to 10 parts by mass, preferably 0.05 to 5 parts by mass, more preferably 0.05 to 1 parts by mass, with respect to 100 parts by mass of PVC. 0.6 parts by mass is more preferable.

<Boron-based compounds>
Examples of boron compounds include borate compounds, borate oxides, borosulfides and boronitrides. Among these, borate compounds are preferable, and among these, zinc borate is particularly preferable.

  Although content of a boron-type compound is 10-55 mass parts with respect to 100 mass parts of PVC, 10-35 mass parts is preferable, and 10-20 mass parts is more preferable.

When extruding the sheath of the power cable as the compounding amount of the isocyanurate compound increases in order to improve the termitability of the sheath of the power cable, the odor and smoke of the organic compound are easily generated, and the productivity aptitude deteriorates. Do.
The inventors of the present invention have found that boron compounds such as zinc borate act as a flame retardant or a flame retardant auxiliary, but exhibit ant-proofing properties. Moreover, it was also found that the isocyanurate compound improves cold resistance. In addition, as for a boron compound, it exists in the tendency for cold resistance to fall, so that compounding quantity increases.

  As described above, the content of the boron-based compound is 10 to 55 parts by mass and the content of the isocyanurate compound is 0.05 to 10 parts by mass with respect to 100 parts by mass of PVC. It is possible to maintain high levels of resistance and cold resistance, and moreover, it is excellent in the production suitability in extrusion processing.

<Other ingredients>
The flame retardant / antitermite composition of the present invention may contain a flame retardant or flame retardant aid other than the boron compound as an additive other than the resin component.
Such a flame retardant or flame retardant aid is not particularly limited, but metal water such as antimony trioxide, polytetrafluoroethylene, silicon dioxide, hydrotalcite, magnesium bicarbonate, magnesium hydroxide or calcium hydroxide Oxides, zinc oxide, aluminum oxide, magnesium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, phosphorus compounds and surface treatment products thereof, melamine, melamine cyanurate, pentaerythritol, dipentaerythritol, tripentaerythritol, monopentaerythritol And polytetrafluoroethylene.
Among these, antimony trioxide and metal hydroxides are preferable from the viewpoint of further improving the flame retardancy.
The content of the flame retardant or flame retardant aid other than the boron compound is not particularly limited as long as the properties of the flame retardant / antitermitator composition of the present invention are not impaired.

In addition, if necessary, additives such as UV absorbers, light stabilizers, antioxidants, lubricants, crystal nucleating agents, softeners, antistatic agents, metal deactivators, antibacterial and antifungal agents, pigments, etc. You may mix | blend.
The content of such an additive is not particularly limited as long as the properties of the flame-retardant anti-terminant composition of the present invention are not impaired.

<Use>
The flame retardant termite composition of the present invention is particularly preferably applied as a sheath of the outermost layer of a power cable.
In particular, the flame retardant / antiterminator composition of the present invention has a high level of flame retardancy, termit resistance, and cold resistance, which makes it possible to form a single-layered sheath, which results in the cost of producing a power cable. Can be lowered.

<< Power cable >>
The power cable of the present invention is a power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shield layer and a sheath are laminated in this order on a conductor, A flame retardant and ant composition.
Specifically, for example, as shown in FIG. 1, an inner semiconductive layer 2, an insulator layer 3, an outer semiconductive layer 4, a shielding layer 5 and a sheath 6 of one layer are sequentially coated on a conductor 1 ing.
In the present invention, as in conventional power cables, the sheath is one layer rather than two or three layers.
In FIG. 2, the sheath has a two-layer structure, and has an ant-proof sheath 6-2 on the flame retardant sheath 6-1.

In the present invention, the number of hearts may be single (one) or multiple (for example, three).
Here, for example, three cores bundle at least three single cores each having at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, and a shielding layer on a conductor, and the bundled surface is It is covered with inclusions, restraining tape, sheath and the like.
Below, it demonstrates from a conductor in order.

<Conductor>
The conductor is preferably copper or a copper alloy, aluminum or an aluminum alloy, and the cross-sectional shape may be circular or rectangular, but in the present invention, copper or a copper alloy is preferably circular.
The surface of the metal wire may be plated with tin, silver or the like, and the conductor may be either a single wire or a stranded wire.

Sectional area and shape of the conductors varies depending on the voltage class and laying condition of the cable, but are not limited to, the cross-sectional area of the conductor is preferably 2~4000mm ^2, 150~2000mm ² is more preferable.
In addition, the surface of such a metal wire may be plated with tin, silver or the like, and the conductor may be either a single wire or a stranded wire.
In the case of a stranded wire, the configuration or shape of the conductor is preferably the configuration or shape used in a normal power cable, and the circular stranded wire [7 / 0.6 (line / mm), 7 / 0.8 (line / line)] mm), 7 / 1.0 (book / mm), 7 / 1.2 (book / mm)], divided compression twisted wire or circular compression twisted wire may be used, but circular compression twisted wire preferable.
In addition, a division | segmentation compression strand is also called a division | segmentation conductor, and is a division | segmentation conductor for electric power cables which intervenes an intervention thing between each segment.

<Internal semiconductive layer>
The inner semiconductive layer can generally use the inner semiconductive layer used in a power cable.
The inner semiconductive layer may be, for example, one coated with a conductive material of a fibrous (cloth) tape, an extruded one in which carbon is mixed with polyethylene, or a combination thereof. The inner semiconductive layer is preferably formed by crosslinking the inner semiconductive layer resin composition. The resin composition for the inner semiconductive layer usually contains a resin for the inner semiconductive layer, a conductive material, a crosslinking agent and an antiaging agent.

The resin for the inner semiconductive layer is not particularly limited, but usually an ethylene-based polymer is used. The ethylene-based polymer is not particularly limited as long as it is a polymer containing ethylene as a repeating unit, and for example, polyethylene (low density polyethylene, high density polyethylene), ethylene-vinyl acetate copolymer (EVA), ethylene -Ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-1-butene copolymer, ethylene-α-olefin copolymer, ethylene-propylene diene rubber ( EPDM). These can be used alone or in combination of two or more. Among these, polyethylene and ethylene-vinyl acetate copolymer (EVA) are preferable, polyethylene is more preferable, and crosslinked polyethylene is more preferable.
Here, the crosslinked polyethylene may be crosslinked by causing the resin composition for the inner semiconductive layer to contain polyethylene and a crosslinking agent.

  The conductive substance is not particularly limited, but usually, conductive carbon is used. Examples of the conductive carbon include carbon black, acetylene black, furnace black, ketjen black, thermal black, graphite and the like. These can be used alone or in combination of two or more. Among them, the content of impurities is small and the electrical properties of the resin for the inner semiconductive layer are not deteriorated, and large aggregates are not formed, and electrical defects at the interface with the resin for the inner semiconductive layer Acetylene black is preferred in that no conductive protrusions are generated.

The inner semiconductive layer may be manufactured using a commercially available semiconductive compound NUCV-9563, 9585, 9589 (manufactured by NUC Co., Ltd.) or the like.
The thickness of the inner semiconductive layer varies depending on the voltage class of the cable and is not limited, but the thickness of the inner semiconductive layer is preferably 2 mm or less, more preferably 1 to 2 mm.

<Insulator layer>
The insulator layer is an insulating layer covering the inner semiconductive layer, and is generally formed by crosslinking the insulator layer resin composition. The resin composition for insulator layers usually contains a resin for insulator layers, a crosslinking agent, and an antiaging agent.
As a resin which comprises an insulator layer, polyolefin resin is preferable and the polyolefin resin denatured by unsaturated organic acid or its derivative is more preferable.
The polyolefin resin is preferably polyethylene, polypropylene, a copolymer with ethylene or propylene, more preferably polyethylene or polypropylene, still more preferably polyethylene, and particularly preferably low density polyethylene.
Among the resins constituting the insulator layer, a crosslinked resin is preferable.
The insulating layer may be manufactured using a commercially available insulating compound HFDA-9253 NT SC, an insulating compound NUCV-9253 (manufactured by NUC Co., Ltd.), or the like.
The thickness and shape of the insulator layer differ depending on the voltage grade and laying conditions of the cable, and are not limited. However, the thickness of the insulator layer is preferably 10 to 23 mm, and more preferably 10 to 17 mm.

<External semiconductive layer>
The outer semiconductive layer, like the inner semiconductive layer, generally has a tape system and an extrusion system.
The outer semiconductive layer is a semiconductive layer that covers the insulator layer, and is generally formed by crosslinking the outer semiconductive layer resin composition. The resin composition for the outer semiconductive layer for forming the outer semiconductive layer usually contains a resin for the outer semiconductive layer, a conductive material, a crosslinking agent and an antiaging agent.

The resin for the outer semiconductive layer is not particularly limited, but usually an ethylene-based polymer is used. Specific examples of the ethylene-based polymer include those similar to the above-mentioned resin for the inner semiconductive layer. Among the ethylene-based polymers, as the resin for the outer semiconductive layer, polyethylene and ethylene-vinyl acetate copolymer (EVA) are preferable, polyethylene is more preferable, and crosslinked polyethylene is more preferable.
Here, the crosslinked polyethylene may be crosslinked by causing the resin composition for the outer semiconductive layer to contain polyethylene and a crosslinking agent.

  The conductive substance is not particularly limited, but usually, conductive carbon is used. Specific examples of the conductive carbon include the same ones as the above-described resin for the inner semiconductive layer.

  The thickness and shape of the outer semiconductive layer vary depending on the voltage grade and laying conditions of the cable, and are not limited, but the thickness of the outer semiconductive layer is preferably 1.5 mm or less, and 0.1 to 1.5 mm. More preferable.

<Shield layer>
The shielding layer (metal shielding layer) may be a tape-like or extruded metal. For example, a copper tape, an aluminum tape, aluminum, lead, a material obtained by extruding SUS, or the like on a cable core may, for example, be mentioned, and preferably an aluminum metal.
The thickness and shape of the shielding layer differ depending on the voltage grade and laying conditions of the cable, and are not limited, but the thickness of the shielding layer is preferably 0.3 mm or less, for example, in the form of a tape, 0.1 to 0 .3 mm is more preferred.

<Sheath>
The sheath provides external protection, including ant-proof and flame-retardant properties of the insulator, and is mainly provided as the outermost layer of the power cable, mainly for mechanical strength and separation from moisture. To aim.
In the present invention, the sheath comprises the flame retardant termite composition of the present invention.
The thickness and shape of the sheath vary depending on the voltage grade and laying conditions of the cable, and is not limited. However, the thickness of the sheath is preferably 4.0 to 6.0 mm, and more preferably 4.0 to 5.5 mm.

<< Method of manufacturing power cable >>
The power cable of the present invention is a power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shielding layer and a sheath are laminated in this order on a conductor.
In the present invention, the inner semiconductive layer, the insulator layer, the outer semiconductive layer, and the shielding layer are sequentially laminated on the conductor, and then provided on the shielding layer with the flame-retardant and anti-corrosion composition of the present invention.
Although any method may be used to provide a sheath on the shielding layer using a flame retardant and antite composition, in the present invention, it is preferable to extrusion coat the flame retardant and antite composition, in which case It is easy to handle, and convenient and preferable to form a flame retardant and antite composition into a pellet and extrusion-coat using this pellet.
In the present invention, when providing the inner semiconductive layer, the insulator layer, the outer semiconductive layer, and the shielding layer sequentially on the conductor, for example, three layers of the inner semiconductive layer, the insulator layer, and the outer semiconductive layer are simultaneously used. Extrusion is also preferred.

  The present invention will be described in more detail based on examples given below, but the invention is not meant to be limited by these.

Example 1
(Preparation and performance evaluation of flame retardant and ant composition)
The flame retardant and antite composition was prepared as follows, and each sheet was obtained using this composition, and each evaluation was performed.

1) Sheet No. 1 to 5 and production of c1 to c5 Polyvinyl chloride (PVC) [ZEST 1400 Z, manufactured by Shin-ichi Dai-ichi PVC Co., Ltd., average polymerization degree 1,400] in proportions (parts by mass) shown in Table 1 below, triallyl isocyante Nureto (Nippon Kasei Chemical Co., Ltd. Tyck (registered trademark), zinc borate (FIREBREAK 290 manufactured by BORAX, USA) is blended and then kneaded using a roll machine set at 150 ° C. to a thickness of 2 mm and 3 mm A sheet-like sample was produced and subjected to press molding at 170 ° C. for 15 minutes to obtain smooth sheet Nos. 1 to 5 and c1 to c5.
Here, the sheet No. c1 to c5 are comparative examples.

2) Sheet No. Production of c6 Pellet-like nylon [UBE nylon 3024LU manufactured by Ube Industries, Ltd.] was subjected to single-screw extrusion at 210 ° C., and then press-molded for 10 minutes at 220 ° C., smoothed with 2 mm and 3 mm thickness Sheet No. of the comparative example. I got c6.

3) Performance evaluation of each sheet With respect to each sheet obtained as mentioned above, the termite-proof property, a flame retardance, and cold-resistant evaluation were performed as follows.

(Evaluation of ant-proofness)
In each sheet having a thickness of 2 mm, three small-piece samples of 20 mm long and 20 mm wide were prepared, and a forced feeding test was conducted in accordance with JIS K 1571 (2010) "Wood preservative-test method based on performance".
An acrylic cylindrical container with an inner diameter of 80 mm and a height of 60 mm, the bottom of which was hardened with anhydrite, was used, and the sample was placed on a plastic net. In addition, one test body, 150 testite termites, and 15 military ants were placed in one test container, and stored for 3 weeks in a dark environment at room temperature of 28 ± 2 ° C. and a relative humidity of 80% or more.

(Evaluation of flame retardancy)
Three small pieces of 130 mm in length and 6.5 mm in width were prepared from each sheet having a thickness of 3 mm, and a test according to JIS K 7201-2 "Testing method of flammability based on plastic-oxygen index" was carried out.

(Evaluation of cold resistance)
In each sheet having a thickness of 2 mm, three small-piece samples having a length of 38 mm and a width of 6 mm were prepared, and a cold-resistant temperature in accordance with JIS C 3005 "Rubber / Plastic Insulated Wire Testing Method" was carried out.

(Evaluation of manufacturing aptitude)
Each flame retardant and termite composition was melt mixed at 190 ° C. with a Banbury mixer, the mixture was discharged, granulated through an extruder at 190 ° C., and processed into pellets. This was repeated three times.
The condition at this time was observed, and the case where extrusion processing was possible into pellets without exception for all three times was ranked A, once among three times the occurrence of white smoke and organic compound odor was confirmed rank B, 2 When the occurrence of white smoke and organic compound odor was confirmed more than twice, it was evaluated as rank C.

These results are summarized in Table 2 below.
In addition, in Table 2, "-" shows that it is unevaluated.

From Table 2 above, Sheet No. 1 consisting of the flame retardant and ant-proof composition of the present invention. All of 1 to 5 are all excellent in termitability, flame retardancy and cold resistance, and there is no generation of white smoke or organic compound odor even in extrusion processing at 190 ° C., and excellent in production suitability There is.
Moreover, the sheet No. of the present invention. The termitivities of 1 to 5 are comparative sheet No. 1 conventionally used as termiticides. It turns out that it is superior to c6.
On the other hand, the comparison sheet No. As in c2, triallyl isocyanurate alone is compared with sheet No. 1 for comparison. Although it shows ant-proofing property in comparison with c1, the average mass reduction rate is 0.03%, and the sheet No. 1 of the present invention has an ant-ring property. It is not always sufficient as compared to 0.00% of 1 to 5.
In addition, even when triallyl isocyanurate and zinc borate are used in combination, at least ant resistance and cold resistance when the content of the isocyanurate compound and the boric acid based compound per 100 parts by mass of PVC does not satisfy the amounts specified in the present invention. The performance of either sex or manufacturability does not meet the level satisfied.
For example, both triallyl isocyanurate and zinc borate are less than the amount specified in the present invention. c3, a sheet No. 1 having a high content of zinc borate as a comparison sheet. In c4, the ant resistance and the cold resistance can not be compatible, and either the ant resistance or the cold resistance is inferior.
Furthermore, when the triallyl isocyanurate is as much as 15 parts by mass, the sheet No. 1 for comparison is used. As c5 shows, it is considered that the productivity is bad because a large amount of smoke is confirmed.

Here, the comparison sheet No. From the comparison of c1, c2 and c4, it can be seen that zinc borate also exhibits ant-proofing action.
Moreover, sheet No. of comparison. When the amount of zinc borate is as high as 60 parts by mass as in c4, the sheet No. 1 for comparison is used. In comparison with c1 and c2, the sheet No. From the comparison with 55 parts by mass in No. 4, cold resistance decreases, that is, the cold resistance temperature tends to be as high as 0 ° C., and there is a concern about use in cold regions.
Furthermore, sheet No. of comparison. Comparison of c1 and c2 and sheet No. 1 of the present invention From the comparison of 2 and 3, it can be seen that triallyl isocyanurate shows the effect of improving cold resistance.

Example 2
(Manufacturing and performance evaluation of power cables)
The power cable 7 as shown in FIG. 1 configured in the order of the inner semiconductive layer 2, the insulator layer 3, the outer semiconductive layer 4, the shield layer 5 and the sheath 6 on the conductor 1 as follows Manufactured.

1) Power cable No. Production of 1 Using a circular compressed conductor made of copper with a cross-sectional area of 800 mm ^{2 for} the conductor, an internal semiconductive layer made of carbon-added crosslinked polyethylene with a thickness of 1 mm, 11 mm thick crosslinked polyethylene [insulation compound made by NUC Corporation An insulator layer made of NUCV-9253], and an outer semiconductive layer made of carbon-added crosslinked polyethylene having a thickness of 0.5 mm were sequentially provided.
Thereafter, on the outer periphery of the outer semiconductive layer, a shielding layer of aluminum metal, sheet No. 1 manufactured in Example 1 was obtained. Power cable No. 2 to which a 5 mm-thick exterior structure with a water blocking function (sheath) comprising a compound having the same composition as No. 2 was added. 1 was produced.

2) Power cable No. Production of c1 Power cable No. In the production of No. 1, except for the sheath of FIG. 1 being replaced by a two-layer sheath of a flame retardant sheath 6-1 and an ant sheath 6-2 as shown in FIG. As in No. 1, the comparative power cable No. c1 was manufactured.
The sheath 6 had a thickness of 4 mm as the flame retardant sheath 6-1, and the sheet No. 6 for comparison was used. Using a compound having the same composition as c1, a polypropylene compound (calp manufactured by Idemitsu Lion Composite Co., Ltd.) was extruded in order with a thickness of 1.5 mm as an ant sheath 6-2.

  The combustion test shown below was done about each power cable manufactured as mentioned above.

(Combustibility evaluation of power cable)
For each power cable, IEEE std. The combustion test based on 383-1974 was implemented. In this test, it is determined to be compatible with the three types of vinyl sheaths described in JEC 3403-2001. In the power cable manufactured this time, it is judged in all three combustion tests whether the combustion length is 1200 mm or less from the burner port and the after flame time is within about one hour.
The obtained results are shown in Table 3 below.
In Table 3 below, the estimated relative manufacturing cost is also described.

From Table 3 above, the power cable No. 1 of the present invention. No. 1 is a power cable No. 1 using a conventional two-layered laminated sheath. Although the total thickness of the sheath was as thin as 5.0 mm and 10% as compared with c1, it was confirmed that both were compatible with the three types of vinyl sheaths described in JEC 3403-2001.
This means that at least the sheath can maintain the same excellent performance as that of a two-layered laminated power cable with a single-layered sheath, which has conventionally been considered difficult.
Moreover, power cable No. 2 which is a conventional power cable. When the relative manufacturing cost with c1 is estimated, the comparative power cable No. Assuming that the manufacturing cost of c1 is 1, power cable No. 1 of the present invention. In No. 1, the total thickness of the sheath is as thin as 10%, and it is estimated to be 0.87 because it is a single layer etc., and it is understood that the manufacturing cost can be suppressed by about 13%.

1 conductor 2 internal semiconductive layer 3 insulator layer 4 external semiconductive layer 5 shielding layer (metal shielding layer)
6 sheath 6-1 flame retardant sheath 6-2 ant sheath 7 power cable

Claims (6)

What is claimed is: 1. A flame retardant and antite composition comprising at least polyvinyl chloride, an isocyanurate compound and a boron compound, respectively.
The content of the isocyanurate compound is 0.05 to 10 parts by mass, and the content of the boron compound is 10 to 55 parts by mass with respect to 100 parts by mass of the polyvinyl chloride. Anticide composition.   The isocyanurate compound content is 0.05 to 0.6 parts by mass, and the boron compound content is 10 to 20 parts by mass with respect to 100 parts by mass of the polyvinyl chloride. The flame retardant and ant composition according to claim 1.   3. The flame retardant and antitermite composition according to claim 1, which is used for a sheath which is the outermost layer of a power cable. A power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shield layer and a sheath are laminated in this order on a conductor,
A power cable, wherein the sheath comprises the flame-retardant and anti-termite composition according to any one of claims 1 to 3.   The power cable according to claim 4, wherein the sheath has a single-layer structure. A method of manufacturing a power cable having a structure in which at least an inner semiconductive layer, an insulator layer, an outer semiconductive layer, a shielding layer and a sheath are laminated in this order on a conductor,
After sequentially laminating an inner semiconductive layer, an insulator layer, an outer semiconductive layer and a shielding layer on the conductor,
A method of manufacturing a power cable, comprising extrusion-coating the flame retardant and antitermite composition according to any one of claims 1 to 3 on the shielding layer.

Images