JPH046710A - Insulated wire - Google Patents

Abstract

PURPOSE:To obtain a wire having a good anti-wear property and thin coating by coating a conductor with a resin composition, in which a prescribed amount of an inorganic filler of a prescribed characteristic is added to thermoplastic resin having two or more pieces of aryl radicals. CONSTITUTION:An insulated wire is composed by coating a conductor with a resin composition in which an inorganic filler of 0.05 to 10wt.% having an average grain diameter of 0.5mum is added to thermoplastic resin of 100wt.% having two or more pieces of aryl radicals in a structure unit. Further, the insulated wire is that in which a conductor is coated with a resin composition where an inorganic filler of 0.05 to 10wt.% having an average grain diameter of not exceeding 0.5mum is added to a mixture of polyetherimide and poly- sulphone of 100wt.%. In this way, by using engineering plastics, mechanical strength such as an anti-wear property is excluded from being dropped even when a coating of an insulated wire is made thin so as to be able to obtain the insulated wire where a solvent-resisting property is sharply improved.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention makes it possible to apply an extremely thin coating, which allows the layer to be made smaller in diameter, while also providing sufficient mechanical strength and the necessary electrical power. This invention relates to a new insulated wire that has not only insulation performance but also solvent resistance.

[Prior Art] In recent years, communication equipment and precision electronic equipment have shown a remarkable trend toward miniaturization and high-density packaging.Furthermore, many small precision equipment with such various functions are being installed in automobiles, etc. In order to make effective use of limited space, not only the internal wiring of devices, but also the wires that connect these devices are being made with thinner insulators and smaller diameter wires. The demand for this is increasing.

As insulators for the wiring within the precision instruments described above and the fine wiring between devices, resin compositions mainly composed of inexpensive polyvinyl chloride or polyethylene have conventionally been used.

[Problems to be Solved by the Invention] Conventional resin compositions mainly made of polyvinyl chloride or polyethylene as described above have a limit even if they can be made thin, and furthermore, the mechanical There was a problem in that the strength, especially the wear characteristics, was greatly reduced.

So-called engineering plastics have excellent mechanical strength, and as mentioned above, even when made thinner, there is no risk of deterioration in wear resistance, and if they can be used as insulation coatings, it is extremely effective from the perspective of thinning insulation materials. preferred.

Thermoplastic resins having two or more aryl groups (-@-) in their structural units are known as highly functional engineering plastics, with extremely high mechanical strength, flame retardancy, heat resistance, and electrical insulation properties. Due to its excellent properties, it is attracting attention as an insulator for small-diameter insulated wires.

However, this resin has the drawback of low elongation and crazing and cracking when it comes into contact with a solvent under stress such as bending.

Furthermore, even if the environment does not use solvents, if these insulated wires or PVC insulated wires are wired together, cracks may occur due to the plasticizer transferred from the PVC insulators. .

Insulated wires for wiring are usually not used in a straight state, but rather in a bent state. For this reason, since the wires are constantly subjected to stress due to the damage, the wires using the above-mentioned engineering plastics as an insulator could not be put to practical use except in extremely limited cases.

If the above engineering plastics were to be used as an insulator and in order to prevent solvent stress cracks, the only way to do so would be to use them in a stress-free environment or in an environment where there is no solvent at all, which is virtually impossible. It is.

Among the above thermoplastic resins having two or more aryl groups in the structural unit, polyetherimide is one of the typical resins, but in order to increase the elongation of this resin, the same engineering plastics A method of blending polysulfone (Japanese Unexamined Patent Publication No. 56-99252) has been proposed. However, since this polysulfone also has poor solvent resistance, the resulting blend composition has poor solvent resistance, and there is a problem in using it in a state where it is bent or the like.

The purpose of the present invention is to solve the above-mentioned circumstances by significantly improving the solvent resistance of each of the above-mentioned engineering plastics, and to enable their use as insulation coating materials for electric wires. The object of the present invention is to provide a novel insulated wire that has sufficient mechanical strength and insulation performance even when the coating thickness is reduced, and eliminates the risk of solvent stress cracks.

[Means for Solving the Problems] Firstly, the present invention provides 100 parts by weight of a thermoplastic resin having two or more aryl groups in its structural unit, an average particle size of 0.5
It is made by coating a conductor with a resin composition to which 0.05 to 10 parts by weight of an inorganic filler with a particle diameter of 0.05 to 10 μm or less is added. 0.5 μm or less inorganic filler.
The conductor is coated with a resin composition containing 0.5 to 10 parts by weight.

In order to achieve thinner electric wires, the inventors have developed a thermoplastic resin having two or more aryl groups in its structural unit, which is attracting attention as an insulator for medium-sized and small-diameter insulated electric wires in engineering plastics. We conducted intensive studies to improve its solvent resistance. As a result, it was surprisingly confirmed that cracking and crazing resistance against dioctyl phthalate and oil can be significantly improved by incorporating an appropriate amount of an inorganic filler consisting of particles of a specific size. Dioctyl phthalate is added as a plasticizer for vinyl chloride resin, and contact and migration is expected when it is installed alongside a vinyl chloride resin-coated electric wire. Also, oil is a solvent that may be encountered in any environment.

Therefore, it can be said that the fact that excellent improvement effects have been obtained in these areas means that it becomes possible to use the material as an insulator for electric wires.

The thermoplastic resin having two or more aryl groups in the structural unit used in the present invention is as follows.

...(polyetherketone) ...(polyetherimide) ...(boaryarylate) Also included are compositions in which two or more of these resins are blended.

On the other hand, from among the resins mentioned above, we focused on a mixture of polyetherimide and polysulfone, which has a large improvement effect on elongation as described above, and conducted a similar study on its resistance to solvent stress cracking, which is an unresolved issue. It was also confirmed that solvent stress cracking properties were significantly improved simply by mixing an appropriate amount of an inorganic filler consisting of particles of a specific size into the resin.

Polyetherimide used in the present invention is a thermoplastic resin having an ether bond and an imide bond in its molecule, and its typical structure is represented by the following formula.

...(Polysulfone) ...(Polyethersulfone) Polysulfone is a thermoplastic resin having an arylene bond, an ether bond, and a sulfone bond, and a typical one is represented by the following formula.

The ratio of polyetherimide and polysulfone is specially specified,
However, it is preferred that the amount of polysulfone be 20% by weight or more of the resin component from the viewpoint of improving elongation.

In the present invention, the inorganic filler that has been found to be effective in preventing solvent stress cracking has an average particle size of 0.5 μm or less. If it is larger than this, excessive stress concentration will occur in the filler itself, and the effect of improving solvent stress cracks may be lost. Regarding the blending amount, if it is less than 0.05 parts by weight, it will not be effective against solvent stress cracking.
If it exceeds 10 parts by weight, the elongation when used as an insulator will be greatly reduced. As the inorganic filler, so-called non-oriented fillers whose shape is close to spherical or granular are preferable.From this point of view, carbon black, silicon dioxide, titanium dioxide, wet zinc oxide, barium sulfate, colloidal calcium carbonate, heavy Examples include, but are not limited to, calcium carbonate and magnesium oxide.

It also includes those subjected to surface treatment to improve adhesion with resin.

Possible mechanisms of action of such inorganic fillers are as follows. In other words, at the interface between the inorganic filler particles and the resin in the stressed resin composition, many peelings or minute cavities occur in the direction perpendicular to the stress, and the fracture energy is released before large cracks such as crazing or cracks occur. This is thought to be to dissipate the However, this is still in the realm of speculation, and the details are still unclear.

In addition to the above-mentioned inorganic fillers, the resin composition of the present invention may contain other compounding agents such as softeners, plasticizers, heat stabilizers, anti-aging agents, pigments, flame retardants, etc. depending on the purpose. I can do it.

Furthermore, if necessary, it is also possible to blend a reactive monomer such as triallyl isocyanurate or diallyl phthalate into the resin composition, extrusion coat it onto an electric wire, and then crosslink it by irradiating it with ionizing radiation.

``Examples'' The present invention will be specifically explained below with reference to Examples and Comparative Examples.

A resin composition having the amount shown in the upper column of Table 1 was prepared, and this was applied onto a 0.3 mm' annealed copper stranded wire conductor with a coating thickness of 0.1.
A sample insulated wire was obtained by extrusion coating so as to give -.

Regarding solvent resistance as an evaluation item, wire samples subjected to self-post-winding were immersed in dioctyl phthalate or motor oil at 50°C, and the occurrence of crazing and cracking was visually observed for 10 days.

In addition, regarding elongation, it is based on J I5C3005,
The measurement was performed using a test piece made into a tube shape by pulling out the conductor.

The respective evaluation results are shown in the lower column of Table 1.

Examples 1 to 3 are examples in which polyetherimide was used as the resin and a predetermined amount of silicon dioxide having an average particle diameter defined by the present invention was blended, and no crazes or cracks were observed and the elongation was large. Examples 4 and 5 are examples in which polysulfone was used as the resin and titanium dioxide within the range specified by the present invention was used as the inorganic filler, and no cracks or clay damage were observed here either. Examples 6 and 7 in which polyarylate was used as the resin and carbon black was used as the inorganic filler also showed excellent results.

On the other hand, in Comparative Examples 1 to 3 in which polyetherimide, polysulfone, and polyarylate were used alone and no inorganic filler was used, crazes or cracks occurred in both dioctyl phthalate and motor oil. Further, even if an inorganic filler is used, in the case of Comparative Examples 4 to 9, in which the average particle size and the blending amount are out of the range specified by the present invention, cracks or crazes occur or the elongation is decreased.

Furthermore, a resin composition having the amount shown in Table 2 was prepared, and this was applied onto a 0.3 mm2 annealed copper stranded wire conductor with a coating thickness of 0.
．． A sample insulated wire was obtained by extrusion coating to a thickness of 1 mm.

The measurement methods for solvent resistance and elongation in the evaluation items are the same as in Table 1.

The respective evaluation results are shown in the lower column of Table 2.

Examples 1 to 7 show the results for electric wires coated with the resin composition defined by the present invention, and both solvent resistance and elongation are good.

On the other hand, Comparative Examples 4, 5.6, in which an inorganic filler with an average particle diameter outside the range of the present invention was used, Comparative Examples 2, 3, in which the amount added was out of the specified range, and no inorganic filler was added at all. Comparative Example 1 has insufficient solvent resistance or elongation.

[Effects of the Invention] As explained above, according to the present invention, by using so-called engineering plastics, even if the coating of the insulated wire is made thinner, there is no risk of deterioration of mechanical strength such as wear resistance. This greatly improved solvent resistance makes it possible to obtain thin-walled, small-diameter insulated wires with excellent properties, and its industrial significance is that it can appropriately respond to the miniaturization and weight reduction of today's equipment. There's something big.

Claims (2)

[Claims] (1) A resin composition prepared by adding 0.05 to 10 parts by weight of an inorganic filler with an average particle size of 0.5 μm or less to 100 parts by weight of a thermoplastic resin having two or more aryl groups in the structural unit is placed on a conductor. A coated insulated wire. (2) Mixture 1 of polyetherimide and polysulfone
An insulated wire comprising a conductor coated with a resin composition obtained by adding 0.05 to 10 parts by weight of an inorganic filler having an average particle size of 0.5 μm or less to 0.00 parts by weight.