JP3449895B2 - Foam resistant polyurethane flat cable for indoor assembled electric wire - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat type cable used in an indoor electric wire (unit) that does not deteriorate even when it comes into contact with foamed polyurethane used as a heat insulating material.

[0002]

2. Description of the Related Art Conventionally, an indoor electric wire (unit)
Is known as an electric wiring system used for the purpose of labor saving of indoor wiring work for buildings, apartment houses, factories and the like. This indoor assembled wire is manufactured by the manufacturer in advance by dividing the necessary electric wiring circuit into several blocks to form units, connecting and connecting the units, and molding insulating the connecting portions. It is a kind of indoor prefabricated cable that completes the necessary electrical wiring circuit. As this indoor electric wire, a cable whose conductor is covered with a vinyl chloride resin insulator and whose outside is covered with a vinyl chloride resin sheath (hereinafter referred to as "vinyl insulated vinyl sheath cable" or "VVF") is generally used. ing.

In general, in a building such as a building, a heat insulating material is used on the inside of the outer wall for the purpose of preventing dew condensation and energy saving such as cooling and heating by heat insulation. At present, as the heat insulating material, from the viewpoints of heat insulating effect, workability, cost and the like, the heat insulating material made of polyurethane foam by a method of spraying the polyurethane foam composition onto the outer wall is most often used. The polyurethane foam composition generally contains a tertiary amine or the like as a curing catalyst (reaction accelerator) for curing at room temperature. This tertiary amine is characterized in that it immediately starts the curing of the polyurethane foam composition immediately after it is sprayed on the inside of the outer wall to prevent dripping (immediate curing property). It is the best curing catalyst from the standpoint of formation.

However, the above vinyl as an indoor electric wire is provided on the inside of the outer wall of the building provided with the foamed polyurethane heat insulating material formed by using the foamed polyurethane composition containing the tertiary amine as described above. When an insulated vinyl sheath cable is used, it may come into contact with or be covered by the polyurethane foam insulation. In this case, there is a problem that the tertiary amine remaining contained in the foamed polyurethane heat insulating material has a strong reducing action and accelerates the dehydrochlorination reaction of the vinyl chloride resin of the cable to accelerate the deterioration. Further, in this case, the foamed polyurethane heat insulating material impedes heat dissipation of the vinyl-insulated vinyl sheathed cable, which causes a problem that the allowable current of the cable is reduced.

Among the above-mentioned problems, as a measure against the problem of deterioration of vinyl chloride resin of vinyl-insulated vinyl sheathed cable, as a countermeasure, a portion of the cable which is conventionally used as an indoor electric wire is in contact with or covered by a foamed polyurethane heat insulating material. The method has been adopted in which the resin is put in a conduit tube made of polyethylene, polypropylene or the like to be shielded from the foamed polyurethane heat insulating material, or a polyester tape or a metal evaporated tape is sandwiched between the foamed polyurethane heat insulating material and the cable. However, these conventional countermeasures have a problem in that the article cost is increased, and the construction process is complicated and the construction cost is increased. Further, among the above-mentioned problems, there has not been proposed yet a method of satisfying the problem of the reduction of the allowable current.

[0006]

Therefore, the problem of deterioration due to the tertiary amine contained in the foamed polyurethane heat insulating material of the cable used in the above-mentioned conventional indoor assembled wire is solved by the conventional method. It is possible to solve the problem more easily by using a conduit tube, polyester tape, metal evaporated tape, etc. as in the countermeasures, without complicating the construction process or increasing costs, and heat the foamed polyurethane insulation of the cable. It is an object of the present invention to provide a method capable of sufficiently solving the problem of a reduction in allowable current due to the inhibition of radiation.

[0007]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the inventors of the present invention have mixed an ethylene copolymer and a silane coupling agent with low density polyethylene to obtain a cross-linking catalyst or ionization property. The flexible crosslinked low density polyethylene composition obtained by crosslinking using radiation does not contain vinyl chloride resin at all, has excellent chemical resistance, and even if it contacts or is covered with a foamed polyurethane heat insulating material, the heat insulation The material is not deteriorated by the tertiary amine contained in the material, has the same flexibility as vinyl chloride resin, and has excellent workability and maneuverability. When used as a body, the permissible current is about 1.6 times larger than that of vinyl chloride resin. It was found that those were.
In addition, when the low density polyethylene to be used in synthesizing this flexible crosslinked low density polyethylene composition is a linear low density polyethylene produced using a metallocene catalyst, the present inventors do not necessarily use an ethylene-based copolymer. It has been found that a material obtained by mixing it with a silane coupling agent without using it and crosslinking it is also an excellent insulator for a cable used as an indoor assembled wire. The present invention has been completed based on these findings.

That is, the first invention of the present invention is a flat cable for an indoor assembled wire, which does not include any vinyl chloride resin as an insulator, and has an ethylene copolymer and 4 to 6 parts by weight in low density polyethylene. The present invention relates to a foamed polyurethane-resistant flat cable for indoor assembled wires, characterized by using a flexible crosslinked low density polyethylene composition obtained by mixing and crosslinking the silane coupling agent. In addition, the second invention of the present invention is a flat cable for an indoor electric wire, wherein the linear low density polyethylene produced by using a metallocene catalyst, which contains no vinyl chloride resin as an insulator, has a thickness of 4 to 5.
The present invention relates to a foamed polyurethane-resistant flat cable for indoor assembled wires, which comprises a flexible crosslinked low-density polyethylene composition obtained by mixing 6 parts by weight of a silane coupling agent and crosslinking the mixture. According to the flat cable for indoor assembled wire according to the first or second invention of the present invention, the foamed polyurethane can be obtained without incurring the conventional high cost of articles, complicated construction process, and high construction cost. Deterioration of the insulator when contacted or covered with the composition is suppressed. Furthermore, since the allowable current of the flexible cross-linked low-density polyethylene composition is 1.6 times larger than that of vinyl chloride resin, even if the allowable current decreases due to the heat dissipation inhibition of the heat insulating material, it is required in the circuit. It is easy to ensure a predetermined allowable current.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the first invention of the present invention, as the low density polyethylene used as a raw material of the flexible crosslinked low density polyethylene composition as an insulator, various low density polyethylenes which have been heretofore known and are commercially available. Polyethylene can be appropriately selected and used. Examples thereof include low density polyethylene (LDPE) generally produced using a combination catalyst of a transition metal compound and an aluminum compound, or linear low density polyethylene (LLDPE), or linear low density polyethylene produced using a metallocene catalyst ( m-LLDPE) and the like. These low-density polyethylenes can be used alone or in combination of two or more, if necessary.

As the ethylene copolymer, various conventionally known and commercially available ethylene copolymers can be appropriately selected and used. Examples thereof include ethylene ethyl acrylate copolymer (EEA), ethylene vinyl acetate copolymer (EVA) and ethylene propylene copolymer (EPM). These ethylene-based copolymers may be used alone or in combination of two or more, if necessary.

Also, as the silane coupling agent, it is possible to appropriately select and use from various conventionally known and commercially available silane coupling agents. Examples thereof include vinyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane and the like. These silane coupling agents may be used alone or in combination of two or more, if necessary. Of these silane coupling agents, vinyltrimethoxysilane (VTMS) is most preferably used.

Dicumyl peroxide (DCP) is used as a crosslinking agent in the synthesis of the flexible crosslinked low density polyethylene composition used in the first invention of the present invention.

The flexible cross-linked low density polyethylene composition used in the first invention of the present invention is obtained by adding the above-mentioned low density polyethylene to an ethylene copolymer, a cross-linking agent, a silane coupling agent and, if necessary, a diglyceride. It can be obtained by mixing a cross-linking agent such as mill peroxide and allowing a cross-linking reaction in the presence of a cross-linking catalyst or using ionizing radiation. At this time, the mixing ratio of the low-density polyethylene, the ethylene-based copolymer, the silane coupling agent, and the cross-linking agent such as dicumyl peroxide used as necessary is 50 to 70 parts by weight of the low-density polyethylene and the ethylene-based copolymer. Combined 50 to 30 parts by weight, silane coupling agent 4 to 6 parts by weight, dicumyl peroxide as a cross-linking agent 1.0 to
2.5 parts by weight are suitable. The low-density polyethylene is hardly soluble in the cross-linking reaction, so that it is generally carried out in a solid phase reaction or a melt reaction. When the crosslinking reaction is carried out in the presence of a crosslinking catalyst, various crosslinking catalysts can be appropriately selected and used as long as they show catalytic activity in the crosslinking reaction.

The soft-crosslinked low-density polyethylene composition used in the second invention of the present invention generally uses a metallocene catalyst as the low-density polyethylene in the method for producing the soft-crosslinked low-density polyethylene composition used in the first invention. Using manufactured linear low density polyethylene,
The ethylene-based copolymer is not used, and the others are obtained according to the method for producing the soft crosslinked low-density polyethylene composition used in the first invention.

It is preferable to add an antioxidant to the flexible crosslinked low density polyethylene composition of the first or second invention of the present invention. As the antioxidant, various conventionally known ones can be appropriately selected and used, and Irganox 1010 is particularly preferably used. Further, if necessary, a compounding agent such as a wetting agent and a coloring agent may be added. Compounding agents such as these antioxidants are generally compounded in the raw material mixture.

In the flat cable for a foamed polyurethane resistant indoor assembled wire according to the first or second aspect of the present invention, the conductor is covered with an insulator made of the above flexible crosslinked low density polyethylene composition, and the outside thereof is chlorinated. A flat cable having a structure covered with a sheath made of vinyl resin (hereinafter referred to as "flexible crosslinked low-density polyethylene composition insulating vinyl sheath cable (flat type)" or "soft CVF"). The conductor is generally coated with an insulator made of a flexible crosslinked low-density polyethylene composition by coating the conductor with a raw material mixture before the crosslinking reaction of the composition by a conventionally known method such as a melt extrusion coating method. Then, after coating, the crosslinking reaction is completed. When the crosslinking reaction is carried out in the presence of a crosslinking catalyst, the crosslinking catalyst is added to the raw material mixture in advance, and when the crosslinking reaction is carried out using ionizing radiation, it is preferable to coat the conductor and then irradiate with the ionizing radiation. It is common. As the sheath made of vinyl chloride resin, any conventionally known sheath can be arbitrarily used, and its formation can also be performed by appropriately selecting a conventionally known method. Also,
The foam-resistant polyurethane flat cable according to the present invention can be used as an indoor assembled wire only in an electric wiring circuit part which is in contact with or covered by the foaming polyurethane composition among all necessary electric wiring circuits. It goes without saying that it can be used as an indoor electric wire in an electric wiring circuit.

[0017]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1 to 7 Each of the raw material mixtures having the compositions shown in Table 1 was placed on a conductor having a diameter of 1.60 mm at 180 to 200 ° C. with a melt extruder.
Was melt-extruded and coated to form an insulating layer having a thickness of 0.80 mm. A flat cable (soft CVF) was prepared by bundling these two and providing a sheath made of vinyl chloride resin (PVC) for commercial use having a thickness of 1.50 mm. The insulation deterioration and the normal allowable current of each of the produced cables were measured, and the allowable current when the foamed polyurethane composition was contacted and the allowable current when the composition was completely contained in the composition were measured. These measurement results showed similar values in each of the examples. The results of these measurements are shown in Table 2. The measurement of each measurement item of each cable is performed as follows. Insulation deterioration: Cover with polyurethane foam, 100 ° C x 48
After heating for 0 hour, check the degree of discoloration of each cable insulation.
If there was any discoloration, it was judged as deterioration. Normal allowable current: Up to 60 for vinyl according to the Electrical Appliance and Material Law
The use upper limit temperature of 90 ° C. and cross-linked polyethylene is set to 90 ° C., and the energizing current until reaching this temperature was measured. Allowable current upon contact with foamed polyurethane composition: Each cable was contacted with foamed polyurethane and the energizing current was measured when the above-mentioned upper limit temperature of use was reached. Permissible current when the foamed polyurethane composition was completely contained: Each cable was completely covered with the foamed polyurethane, and the energizing current until the above upper limit temperature was reached was measured.

[0018]

[Table 1]

Note) LDPE: Low density polyethylene (UBEC540 manufactured by Ube Industries Ltd.) LLDPE: Linear low density polyethylene (NUC G5651 manufactured by Nippon Unicar Co., Ltd.) m-LLDPE: Metallocene linear low density polyethylene (Ube Industries Ltd. UMERIT 0540F) EEA: ethylene ethyl acrylate copolymer (Nippon Unicar Co., Ltd. NUC-6070) EVA: ethylene vinyl acetate copolymer (Nippon Unicar Co., Ltd.)
NUC-3185 manufactured by Co., Ltd. EPM: ethylene propylene copolymer (EP-02P manufactured by Japan Synthetic Rubber Co., Ltd.) VTMS: silane coupling agent; vinyltrimethoxysilane DBTL: crosslinking catalyst; dibutyltin dilaurate DCP: crosslinking agent Dicumyl peroxide AO: Antioxidant; Irganox 1010

Comparative Example 1 The same vinyl chloride resin as that used in Example 1 was used, and a thickness of 0.80 m was formed on the same conductor having a diameter of 1.6 mm as in Example 1.
A flat cable (VVF) was prepared by providing an insulating layer made of vinyl chloride resin of m, bundling the two, and further providing a sheath made of vinyl chloride resin having a thickness of 1.50 mm on the bundle. The same measurement items as in Example 1 were measured for this cable. The measurement results are shown in Table 2.

[0021]

[Table 2]

[0022]

INDUSTRIAL APPLICABILITY In the flat cable for indoor electric wire according to the present invention, it is possible to contact the foamed polyurethane heat insulating material without incurring the conventional high cost of articles and the high construction cost due to the complicated construction process. Alternatively, deterioration of the insulator when covered is suppressed, and since the allowable current is large, it is easy to ensure the predetermined allowable current required in the circuit even if it is reduced due to the heat dissipation inhibition of the heat insulating material.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tamio Kawai 2771 Ooka, Numazu City, Shizuoka Prefecture Yazaki Electric Wire Co., Ltd. (72) Inventor Masayuki Hayashi 2771 Ooka, Numazu City, Shizuoka Prefecture In-house (72) Inventor, Tetsuo Sekikawa Shimizuura 1-3-2, Shibaura, Minato-ku, Tokyo (56) References JP-A-1-113446 (JP, A) JP-A-7-228615 (JP, A) JP-A-8-73670 (JP, A) JP-A-54-76648 (JP, A) JP-A-8-185712 (JP, A) JP-A-9-77918 (JP, A) Actually open flat 5-20268 (JP, U) Publication 57-39647 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01B 3/16-3/56 H01B 7/02 H01B 7/08

Claims (2)

(57) [Claims] 1. A flat cable for an indoor assembled wire, wherein 50 to 70 parts by weight of low-density polyethylene, 50 to 30 parts by weight of an ethylene-based copolymer and 1.0 of a cross-linking agent are used as insulators.
2.5 parts by weight of silane-coupling agent 4 to 6 parts by weight of the <br/> mixture composed by crosslinking soft-bridge low density polyethylene composition foaming polyurethane of indoor set, characterized by using Flat cable for electric wire. 2. In a flat cable for indoor assembled wire, 100 parts by weight of linear low-density polyethylene produced by using a metallocene catalyst as an insulator is crosslinked with 1.0 to 2.
5 parts by weight of silane-coupling agent 4-6 is crosslinked by mixing parts by using a flexible cross-linked low density polyethylene composition comprising, foaming polyurethane of indoor sets electric wires characterized in that it is free of vinyl chloride resin Flat cable for use.