WO1997039459A1

WO1997039459A1 - Ant-proof cable

Info

Publication number: WO1997039459A1
Application number: PCT/JP1997/001271
Authority: WO
Inventors: Masumi Tanikita
Original assignee: Polyplastics Co., Ltd.
Priority date: 1996-04-12
Filing date: 1997-04-11
Publication date: 1997-10-23
Also published as: AU727646B2; JPH09282950A; AU2521997A

Abstract

An ant-proof cable comprising a protective covering layer provided on the outermost layer of the cable, the protective covering layer being formed of a polyacetal resin (e.g., a polyacetal resin or a composition composed mainly of a polyacetal resin and containing other resin).

Description

Description Title of the invention Termite-proof cable Technical field

TECHNICAL FIELD The present invention relates to a termite-preventing cable in which a polyacetal-based resin protective coating layer is provided on the outermost layer of the cable to prevent termite damage due to the excellent properties of the polyacetal-based resin. Background art

There have been many reports of damage to electric wires or cables (hereinafter referred to collectively as "cables" in the present invention) by small animals, but the most common case of damage is termite damage. In recent years, the role of cables has become more important year by year in increasing the density of information and energy transmission. Therefore, prevention of damage by small animals is also increasing in importance. Most of the materials commonly used for coating cables are general-purpose resins such as polyvinyl chloride resin (also abbreviated as PVC) and polyethylene resin, and it is difficult to avoid termite damage. .

In recent years, it has become mainstream to take physical measures by applying nylon 12, which is a tough resin, to the outermost layer as a termite control measure for cables. As a chemical measure, the addition of a termiticide to polyvinyl chloride resin for general coating has also been used in part. However, in the above physical measures, unless the thickness of the protective coating layer of nylon 12 is 0.7 mm or more, a sufficient termite-controlling effect cannot be obtained, and the flexibility of the cable is impaired. In addition, the material price is high, the extrudability is poor, and the processing speed cannot be increased.

In addition, chemical countermeasures have not been able to satisfy both the sufficient termite-controlling effect and long-term stability, and the current situation is that research and development of effective drugs are still being conducted. Disclosure of the invention

The present inventor has conducted intensive studies in view of the current state of termite control technology, and as a result, by providing a protective coating layer made of polyacetal resin on the outermost layer of the cable, the above-mentioned problem of termite control technology was solved, and The present inventors have found that an ant-prevention cable having economical rationality that can be effectively avoided and that improves the production work efficiency can be obtained, thereby completing the present invention. That is, according to the present invention, there is provided a termite-proof cable characterized in that a protective covering layer made of a polyacetal resin is provided on the outermost layer of the cable.

Further, according to the present invention, the termite prevention resin is characterized in that the polyacetal-based resin is made of a polyacetal resin (also abbreviated as POM) or a composition with another resin mainly composed of a polyacetal resin. Bull is provided.

Further, according to the present invention, there is provided the termite-preventive cable, wherein the composition mainly composed of the polyacetal resin comprises a polyacetal resin, a thermoplastic polyurethane resin and / or a core-shuttle polymer.

Further, according to the present invention, the protective coating is characterized in that a protective coating layer made of a polyacetal resin and a polyvinyl chloride resin coating layer located thereunder are in contact with each other to form a coating layer. An ant cable is provided.

Further, according to the present invention, there is provided the termite-proof cable, wherein the surface coating Vickers hardness of the protective coating layer made of polyacetal resin is 2.5 or more. In the present invention, the term "polyacetal-based resin" refers to a polyacetal resin, and also a composition containing a polyacetal resin as a main component (50% by weight or more) and a compounding agent that can be blended with the polyacetal resin. Point to. BEST MODE FOR CARRYING OUT THE INVENTION The cable of the present invention includes an electric wire as described above and transmits light, electricity, etc., and may be made of any material and shape. For example, glass fiber for an optical cable, various types of electricity and telephone lines The present invention can be applied to a metal wire or the like. FIG. 1 shows an example of a cable according to the present invention. In FIG. 1, a termite cable 7 has a plurality of insulated wire cores 3 in which an insulating layer 2 made of polyethylene resin, cross-linked polyethylene resin, or polyvinyl chloride resin is provided on a conductor 1 made of aluminum, copper, or the like.

(In this example, two strands) are twisted with each other, and if necessary, the sheath layer 5 is formed on the outside of the twisted twisted wire 4 by holding down with a synthetic resin sheet or tape. (Outside) is provided with a protective coating layer 6 made of polyacetal resin. The above-mentioned polyacetal resin may be a polymer compound having a main unit (50 mol% or more) mainly composed of oxymethylene groups (one CH ₂₀ —), and other polyoxymethylene groups besides polyoxymethylene homopolymer and oxymethylene groups. Any of copolymers, terpolymers, and block polymers containing constituent units that can be copolymerized can be used. The molecule may have not only a linear shape but also a branched or crosslinked structure.

The above-mentioned composition mainly composed of a polyacetal resin is a composition containing another resin as a so-called island structure or network structure. There are no particular restrictions on the types of other resins to be combined with the polyacetal resin, including acrylic resins such as thermoplastic polyurethane resins, core shell polymers, polyester elastomers, polyamide elastomers, ABS resins, and ethylene-vinyl acetate. Polymers, polyvinyl acetate resins, olefinic resins such as copolymers of α-olefin and glycidyl esters of α, -unsaturated acids, vinyl chloride resins, polyethylene terephthalate resins, polybutylene terephthalate resins Resin, polycarbonate resin, polyphenylene ether resin, polyphenylene sulfide resin, etc., especially thermoplastic thermoplastic resin. Preferred are resin resins and / or core-shell polymers.

Here, the core-shell polymer (also referred to as a core-shell resin) is an organic compound having a core of a rubber-like polymer and a shell of a glass-like polymer, and can be prepared by a known method, It can also be used. The core-shell polymer is obtained by a multi-stage emulsion polymerization method in which a rubber-like polymer as a core is successively coated with a polymer generated in a subsequent polymerization step to form a shell. As the core of the rubbery polymer, for example, a conjugated diene or an alkyl acrylate or a mixture thereof can be mentioned. In the polymerization, a copolymerizable monomer can be copolymerized. Examples of the glassy polymer forming the shell include those obtained by copolymerizing methyl methacrylate alone or a mixture of methyl methacrylate and a copolymerizable monomer. An intermediate layer may be present between the rubbery polymer core and the glassy polymer shell.

In the polyacetal-based resin, various stabilizers such as anti-blocking agents, antioxidants, and ultraviolet absorbers, antistatic agents, flame retardants, flame retardant auxiliaries, and dyes do not impair the effects of the present invention. And a coloring agent such as a pigment, a lubricant, a plasticizer and a crystallization accelerator, a nucleating agent, a release agent, a filler, and the like.

As the polyacetal-based resin used in the present invention, those having a high surface hardness are preferable in terms of high termite-eating effect, and those having a surface pick-up hardness of preferably 2.5 or more, more preferably 3.5 or more And more preferably 3.5 to 15. The thickness of the protective coating layer 6 made of a polyacetal resin is determined in consideration of the termite-preventing cable's required termite-proofing property, the flexibility is not impaired, and the economical efficiency is taken into consideration. Should be 0.1 mm or more, and preferably in the range of 0.2 to 0.7 mm. If the thickness of the protective coating layer made of polyacetal resin is less than 0.1 mm, sufficient termite resistance may not be obtained, and when the cable is bent. In some cases, inconveniences such as the buckling of the bent portion may occur. On the other hand, if it exceeds 0.7 mm, it may be too thick to obtain flexibility, and it is uneconomical. The protective coating layer made of polyacetal resin is formed by coating the polyacetal resin to a predetermined thickness on the insulating layer 2 by ordinary extrusion coating, and simultaneously extruding the polyacetal resin when extruding the insulating layer 2. There is also a method of laminating. Considering economy, the latter coextrusion (coextrusion) method is preferred. If a higher level of termite control performance is required, 2.5% by weight or less of a drin-based or organic phosphorus-based termite can be added to the polyacetal-based resin. It is necessary to prevent the termite-controlling agent from spilling, extruding processability and deterioration of electrical properties. Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

(Method of measuring surface Vickers hardness)

Using a micro-hardness tester (MHT-1 type) manufactured by Matsuzawa Seiki Co., Ltd., the measurement was performed under an environment of 23 ° C under a load condition of 10 gf and 25 seconds. The unit is kgf / mm ^2.

(Examples 1-3, Comparative Examples 1-2)

Specimens (12 mm x 60 mm) composed of various materials such as polyacetal resin, soft polyvinyl chloride resin commonly used for electric wires, and a low surface pickers hardness, were placed on the artificial nest of termites. (Thickness: 6 mm) sandwiched between the top and bottom of akamatsu wood, allowing the termites to freely move on and off the test specimen, and exposed to house termites for 3 months in a dark room at 28 ° C. . The degree of damage to the test specimen was evaluated by visual change in shape.

The evaluation criteria were 5 levels, 5: no change, 4: a trace of galling, 3: a slight galling that can be clearly seen, 2: a clear galling and noticeable , 1: Significant galling, indicated by. In this test, in the case of the polyacetal resin, galling was observed at the corner of the test piece, but galling was not observed at the flat surface. On the other hand, in the case of soft polyvinyl chloride resin, it spread and marked galling was observed in the range.

The materials used, their surface Vickers hardness and the results of the evaluation of the damage are shown in Table 11. Table 1

(Example 4)

A sheath layer of soft polyvinyl chloride resin (1.5 mm thick) outside the two-core conductor with the shape shown in Fig. 1 and a core-shell resin composition of PO MZ urethane resin used in Example 2 outside the sheath layer An anti-termite protective layer (0.5 mm thick) made of a material was formed by a co-extruder, and a coated cable with an outer diameter of 10 mm was produced. Although 6 cm of this cable was exposed to the damage of the termites under the same conditions as in Example 1, no damage to the protective layer of the polyacetal-based resin was found (Evaluation 5). As is clear from the above examples, it is understood that the protective layer made of the polyacetal-based resin exhibits high termite control performance. Also, high and termite-controlling performance can be imparted to the cable without adding an termiticide. Industrial applicability

The termite cable of the present invention has a protective coating layer made of polyacetal resin. It is expected that the termite control performance will be stable and continuous. In addition to satisfying termite control properties, it is possible to obtain cables with high economic rationality, because it does not impair the extrudability and does not particularly require the addition of termite control agents. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional view showing an example of a termite-proof cable according to the present invention.

In FIG. 1, 1 is a conductor, 2 is an insulating layer, 3 is an insulated wire core, 4 is a stranded wire, 5 is a sheath layer, 6 is a protective coating layer made of polyacetal resin, and 7 is a termite-proof cable.

Claims

The scope of the claims

1. An anti-termite cable characterized in that a protective coating layer made of polyacetal resin is provided on the outermost layer of the cable.

2. The termite-proof cable according to claim 1, wherein the polyacetal resin is made of a polyacetal resin, or is made of a composition with another resin mainly composed of a polyacetal resin.

3. The termite-proof cable according to claim 2, wherein the composition of the polyacetal resin with another resin is composed of a polyacetal resin, a thermoplastic polyurethane resin and / or a core-shell polymer.

4. The termite cable according to claim 1, wherein the polyacetal resin protective coating layer and the polyvinyl chloride resin coating layer located inside the protective coating layer are in contact with each other to form a coating layer.

5. The termite-proof cable according to claim 2, wherein the polyacetal resin protective coating layer and the polyvinyl chloride resin coating layer located inside the protective coating layer are in contact with each other to form a coating layer.

6. The termite-proof cable according to claim 3, wherein the protective coating layer made of a polyacetal resin and the polyvinyl chloride resin coating layer located in the inner layer are in contact with each other to form a coating layer.

7. The termite-proof cable according to any one of claims 1 to 6, wherein the surface pick-up hardness of the protective coating layer made of polyacetal resin is 2.5 or more.