JPS60240010A - Anti-termite cable - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to electric wires and cables coated to prevent damage caused by termites.

(Background of the Invention) Electric wires and cables are exposed to various usage conditions and environments, and their lifespan is usually determined by electrical and mechanical deterioration of their jackets and insulators. Many accidents have been reported.

Termite prevention methods for electric wires and cables vary slightly depending on the type of termites, environment, etc., but basically, (a) imparting termite-proofing properties to the electric wires and cables themselves, and (b) electric wires and cables. It can be roughly divided into two types: imparting anti-termite properties to the area around the installation.

In other words, in method (a), the structure and materials of the wires and cables are devised, a layer containing termiticide is added,
Methods such as applying termiticides can be cited, and method (b) includes applying termite-proofing treatment to the soil along the installation route.

Among these methods, conventionally the most commonly adopted method has been to incorporate a termiticide into the sheath material of the wires and cables from the viewpoint of processing the wires and cables and mainly from the viewpoint of cost.

In particular, so-called dorin-based drugs such as aldrin, dieldrin, and endrin were mainly used, but it became clear that they were harmful to humans and animals and caused environmental pollution.
Its use is currently prohibited (October 2, 1980, Cabinet Order No. 802).

Therefore, instead of using drugs, measures are now increasingly being taken from the viewpoint of structural design and material design.

That is, methods such as protecting the cable itself with a metal sheath or adding a coating layer such as nylon on the cable sheath are beginning to be adopted. However, compared to the method of adding termiticide to the sheath material of electric wires and cables, these methods increase the cost of materials and processing significantly, and also significantly impair the flexibility of electric wires and cables. There are many.

Therefore, in other countries, a method using a sheath material containing a highly effective termiticide is still widely used.

In Japan, this sheath material is made of plastic containing extracts of Japanese cypress wood (Japanese Act 52-34).
623), plastics containing 10% by weight or more of creosote oil (Special Publication No. 30787/1987), PVC containing polyester plasticizers (molecular weight 8,000 or more)
(Japanese Patent Publication No. 55-8810), Y is a C1-C4 alkylidene group, or a resin composition containing 5 to 50 parts by weight of one or more compounds represented by (Japanese Utility Model Publication No. 57-140016) )
, pvc mixed with pheniI lotion or phoxime or chlorpyrifos and zinc octylate or zinc persate etc. (JP-A-58-25012 or JP-A-58-
No. 142927, JP-A-58-169810), etc. are known.

Termite-proofing agents used for electric wires and cables must have excellent long-lasting anti-termite effects because the electric wires and cables are used for long periods of time.

In particular, when considering the processing of coating materials for electric wires and cables, there is very little volatilization during the mixing and extrusion process of the coating material, and it is thermally stable for several minutes to one hour at a temperature of about 160 to 220 degrees Celsius. It is desirable that the material has good properties, and that it does not cause blooming or the like even after molding. or,
It is of course undesirable that the properties of the substrate, including mechanical properties, electrical properties, etc., of the material are impaired after molding.

However, there has been no termite-proofing cable that satisfies the above-mentioned characteristics and has a sheath containing a termiticide with excellent termite-proofing effects.

(Disclosure of the Invention) As a result of various studies, the present inventors have found that a specific organic phosphorus agent that has excellent termite-proofing effects and low thermal decomposition properties especially at high temperatures has been applied to PvC, which is widely used as a sheath material for electric wires and cables. It was discovered that the compound did not cause blooming, etc., and based on this knowledge, the termite-proof cable of the present invention was completed. That is, the present invention is an anti-termite cable characterized by being coated with isopropyl-2-[ethoxy(isopropylamino)thiophosphoryloxy]benzoate as an active ingredient.

The isopropyl-2-[ethoxy(isopropylamino)thiophosphoryloxy]benzoate according to the present invention is commonly referred to as isofenphos.

In the present invention, this infenphos is usually added to the coating composition for electric wires and cables in an amount of 0. O1 to 10% by weight, preferably 0.05 to 5% by weight.

The termite-proof cable of the present invention comprising isofenphos added to the coating composition has the following advantages compared to those using other termite-proofing agents:
The following experiment shows that it not only has anti-termite effect but also has excellent electrical properties necessary for electric wires and cables.

(Test termiticide) Table 1 shows the termiticides used as test termiticides.

-〇- Table 1 Chlorpyrifos 9 Prothiophos 8 Fenitrothion 4 Isofenphos Regarding the termiticide properties of the drugs listed in Table 1, the following termicidal efficacy test was conducted, and the results shown in Table 2 were obtained.

Anticidal efficacy test (knockdown test) (a) Dilution solvent: acetone drug concentration of 0.1% and 1%
And so.

(b) Test termite: Ie Shiroa 1J11 [(c) Test method 2 The termiticidal property of the drug was evaluated based on the mortality rate after 24 hours (25°C) according to the method specified by the Japan Termite Countermeasures Association. .

PvC (degree of polymerization: about 1100-1800) 100 parts plasticizer (phthalate ester 9) 50 parts filler (heavy calcium carbonate) 80 parts stabilizer (tribasic lead sulfate) 5 parts Table 1 The termiticide shown in Figure 1 is mixed with a plasticizer, mixed with a roll at 160°C for about 10 minutes, taken out into a 1 mNmN sheet, and further preheated at 160°C for 10 minutes and pressed for 10 minutes to form an anti-termiticide. Anticide 3%
A 13m x 17c1n sample sheet of additives was obtained. This 1ruL thick PVC sheet was coated on 30 mm square pine sapwood, the overlapping part and end part were completely sealed with adhesive tape with metal tape, and the sheet was subjected to a field test. Field tests were conducted for three years, and the results are shown in Table 3.

Table 8 Table 9- Also, the electrical properties (insulation resistance) of the PVC sheets obtained in the same manner are shown in Table 4.

Table 4 First of all, it can be seen from Table 8 that Prothiophos has sufficient anti-termitic and termiticidal properties as a drug itself, but in field tests, it cannot stand up to Pvc when added at 3%.

Chlorpyrifos is added to 3% PVC as shown in Table 4.
The insulation resistance value of the sheet is reduced to about 1/1483 of that of the additive-free product (a decrease of more than 3 digits), making it unsuitable as a sheath material for electric wires and cables.

In this respect, isofenphos and fenitrothion only show a two-digit decrease, and can maintain the 10111Ω·α that is generally required as a sheath material for electric wires and cables.

(Cable extrusion test) A PVC compound with the same composition as the test sheet was extruded using an extruder as a sheath material, and crosslinked polyethylene
A VC sheathed cable (8CX22SQ) was obtained. Collect an appropriate amount of sample from the PvC sheath of this cable,
The remaining amount of added termiticide in the PvC compound was determined.

The results are shown in Table 5.

(Unit: residual rate %) As shown in Table 5, most of the added amount of fenitrothion decomposes and evaporates, making it impractical.

Although it is possible to improve the survival rate to some extent by lowering the material temperature during extrusion as much as possible, it is necessary to suppress the heat generation in the extruder, so the screw rotation speed must be reduced. As a result, the extrusion speed decreases and the extrusion time increases, which inevitably increases the extrusion cost. On the other hand, PVC doped with isofenphos
Most of the compound remained, which shows that it is an extremely effective termiticide.

Isofenphos does not cause blooming from the sheath surface even after molding.

As described above, the termite-proof cable of the present invention coated with isofenphos as an active ingredient not only has an excellent termite-proofing effect, but also has extremely low volatilization and decomposition of the termiticide during extrusion processing. be.

Claims (1)

[Claims] (1) An anti-termite cape characterized by being coated with isopropyl 2-(ethoxy(isopropylamino)thiophosphoryloxy)benzoate as an active ingredient.