JPS6268854A - Electrically conductive resin composition - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive resin composition having excellent electrical conductivity without lowering the characteristic properties of the base resin, by compounding a resin with a filler consisting of an aluminum-nickel alloy. CONSTITUTION:A resin such as ABS resin, polyethylene, polypropylene, etc., is compounded with 10-40vol% filler consisting of an aluminum-nickel alloy composed mainly of aluminum, containing 5-40wt%, preferably 20-30wt% nickel and optionally containing <=10wt% other component such as silicon, iron, copper, etc. The filler is granular powder having a particle size of 50-1,000mum, flaky powder having a diameter of 150-3,000mum and a thickness of 1-100mum or fibrous filler having a diameter of 10-500mum and a length of 500-30,000mum. Sufficient effect can be attained by the addition of 5-30vol% filler in the case of flaky aluminum alloy filler or 2-20vol% in the case of fibrous filler.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a conductive resin composition, particularly an S conductive resin composition containing an aluminum alloy filler.

[Prior art] Resin materials, which are insulating organic polymer materials with conductive functions, have come to be widely used in various parts such as resistance heating elements, resistors, antistatic materials, and shielding materials. . To this end, it is required to impart conductivity f1 to the resin without impairing its inherent physical properties, such as moldability.

One method for imparting conductivity to a resin is to mix a conductive filler into the resin.

According to this method, a molded body or sheet obtained by molding a resin mixed with a conductive filler can be used as a component as it is, so it is a useful method that can be expected to reduce processing costs.

The S conductive filler blended into conventional conductive resins is
Carbon black, graphite powder.

Carbon-based fillers such as carbon vane, fine metal powders such as nickel, silver, and copper, metal fibers such as brass, stainless steel, and aluminum, and aluminum]-]-glass fibers.

Composite fillers such as nickel-coated mica powder are undesirable due to the following drawbacks.

In the case of carbon-based fillers, their uses are limited because they are not as easily twisted as metals, and their hue is also limited, resulting in poor decorative properties.

Among fine metal powders, nickel and silver are expensive and impractical, while copper powder requires surface treatment to prevent surface oxidation to ensure stable conductivity.

Fibers made of stainless steel, brass, etc. have a high specific gravity and therefore have poor dispersibility, and have the disadvantage that the specific gravity of the obtained molded product is also high.

In composite fillers, the ting layer peels off during the molding process,
There is a possibility that the S conductivity will decrease.

In addition to the above-mentioned conductive fillers, aluminum conductive fillers are attracting attention because they have the advantage of being popular and inexpensive; It has the disadvantage that sufficient conductivity cannot be obtained because the contact resistance between the materials increases. Therefore, as with the other conductive fillers mentioned above, in order to obtain the desired conductivity, it is necessary to increase the amount of filler blended or to form it into a shape that is difficult to mold, such as fibers or coarse particles in the form of flakes. Ta.

[Problems to be Solved by the Invention] The present invention solves the above-described drawbacks of the conventional y# conductive filler and imparts sufficient conductivity to the resin in an amount within a range that does not impair the physical properties of the resin itself. An object of the present invention is to provide a conductive filling material that absorbs moisture.

An object of the present invention is to provide an aluminum-based S conductive filler that can impart sufficient conductivity to a resin in a small amount without sacrificing the advantages of aluminum, which is lightweight and inexpensive.

[Step F for Solving the Problems] The conductive resin composition provided by the present invention is characterized in that it contains an aluminum alloy filler containing 5 to 40% by weight of nickel.

The conductive filler blended into the resin composition of the present invention is made of an aluminum-nickel alloy containing 5 to 40% nickel. In the aluminum-nickel based alloy of the present invention, if the nickel content is less than 5% by weight, sufficient conductivity cannot be obtained, while if the nickel content exceeds 40% by weight, the specific gravity of the alloy will not be large. This is not preferable because it deteriorates the dispersibility and also increases the cost. The preferred nickel content is 20-30% by weight. .

Furthermore, the aluminum-nickel alloy of the present invention has (
silicon, iron, copper, magnesium, manganese, cobalt, chromium, molybdenum (for example, for the purpose of imparting strength, heat resistance, corrosion resistance, workability, etc.).

silver, calcium, indium, bismuth, antimony,
Components such as zinc, lead, vanadium, titanium, cadmium, tin, gallium, and zirconium can also be added. There is no particular restriction on the amount added, but if the amount added is 10 parts by weight or less, the above object can be achieved without particularly impairing the desired effects of the present invention. It is desirable that the alloy specific gravity be 5 or less.

The shape of the aluminum alloy filler having the alloy composition described above is not particularly limited, but fillers in the form of granular powder, flake powder, or fibers are used. Generally, resin compositions containing granular powder have good moldability, and highly conductive molded bodies or sheets can be formed from resin compositions containing flaky powder or fibers. There are no particular restrictions on the particle size of the filler, but the smaller the particle size, the more difficult it is to impart sufficient conductivity, and the larger the particle size, the worse the dispersibility and moldability, which may affect the physical properties of the resulting molded product or sheet. The selection is made taking into consideration that it may have an undesirable effect on Usually, granular powder with a particle size of 50 to 1000 units 1
Flaky powder with a particle size of 150-3000 IIM and a thickness of 1-100 μm or fibers with a diameter of 10-150/11711 and a length of 500-300004 are used. A mixture of these may be used.

The resin in which the aluminum alloy filler of the present invention is blended may be any resin that can be blended with conventional conductive fillers, such as A-8 resin, 'A B S resin, polyethylene, polypropylene, Nori J, polycarbonate, etc. Net-, polystyrene, polyamide, polyvinyl chloride, silicone resin, E
VA resin, EEA resin, etc. are used.

The content of the aluminum alloy filler is determined depending on the required conductivity, but is preferably 10 to 40% by volume. If the blending amount is less than 10% by volume, sufficient conductivity cannot be obtained,
Moreover, if it exceeds 40% by weight, the physical properties of the resin will be impaired, which is not preferable. When the aluminum alloy filler is in the form of flakes or fibers, a smaller amount than the above-mentioned amount (for example, 5 to 30% by volume for flakes and 2 to 20% by volume for fibers) is sufficient.

Although it is essential to incorporate an aluminum alloy filler into the resin composition of the present invention, other optional components such as a plasticizer, a heat-resistant anti-aging agent, a weathering agent, a stabilizer, a dispersant, a mold release agent, and an electrostatic charger may be added as required. Inhibitors, impact modifiers, pigments, coupling agents, antioxidants.

Other conductive fillers may also be blended. - [Examples] The following examples are illustrative for specifically explaining the present invention, and the present invention is not limited to these examples.

Granules containing 1'80% by weight of K.
A resin composition was prepared by blending aluminum alloy powder with a particle size of 149 to 350 μs) and a specific gravity of 3.1 to an ABS resin. The blending ratio was 15% by volume.

The resin composition was injection molded in accordance with a conventional method to obtain 1 q of plate-shaped molded articles having a thickness of 3 mm and a square size of 10 cm.

The volume resistivity of this molded body is A S T M D 2
57, it was found to be 5X 100 Ω-cm.

- - O - The volume resistivity of the molded body obtained in the same manner as in Example 1 was measured using an aluminum alloy filler having the alloy composition shown in Table 1. The results were as shown in Table 1.

Table 1 (Note) $1 Granular filler from 149 to 350*
2 Flaky filler with a diameter of 1000-2000mm and a thickness of 201IIR*3 Diameter 50IJJRte length 50
00*(F)! It was confirmed that a molded body obtained from a resin composition blended with an aluminum alloy filler containing 5 to 40% by weight of nickel filler had high electrical conductivity.

[Effect of the invention 1] When the resin composition containing the aluminum alloy filler of the present invention is used, it is possible to mold a molded body or sheet with exceptionally superior conductivity compared to when a filled wA material made of simple aluminum is mixed. can do. This is because the aluminum-nickel alloy filler of the present invention does not have an electrically insulating oxide film formed on the conventional aluminum shell.
This is thought to be due to the fact that the contact resistance between the fillers is extremely low because a conductive film made of aluminum oxide and nickel oxide is formed.

In the present invention, as described above, since the contact resistance between the fillers is small, the amount of fillers blended can provide at least a sufficiently high conductivity. Therefore, there is no fear that the moldability of the resin will be impaired, which conventionally occurs due to the need to increase the amount of filler blended, and the resin composition of the present invention can be easily molded into molded objects or sheets. In addition to this, the possibility of deterioration of physical properties such as the strength of the resin itself is also avoided.

Furthermore, in the present invention, excellent conductivity can be obtained even when granular powder with high moldability or flake powder with relatively small particle size is used as a filler. It is possible. Therefore, according to the present invention, the filler can be blended into the resin in a uniformly dispersed state, and as a result, a molded article or sheet with uniform conductivity can be molded.

In the present invention, as described above, since the amount of filler blended is small, the obtained molded article or sheet has excellent physical properties.

In particular, since the aluminum-nickel alloy filler of the present invention has higher strength than the aluminum filler, the use of the resin composition of the present invention can impart not only electrical conductivity but also a reinforcing effect.

The present invention also maintains the low cost, low specific gravity, and excellent decorative properties inherent to aluminum-filled materials, so it is possible to form pumice compacts or sheets with excellent hues at low cost. be.

Claims (6)

[Claims] (1) A conductive resin composition containing aluminum as a main component and an aluminum alloy filler containing 5 to 40% by weight of nickel. (2) Claim 1 in which the aluminum alloy filler is in the form of granular powder, flaky powder and/or fibers
The composition described in Section. (3) Aluminum alloy filler has a particle size of 50 to 1000μ
The composition according to claim 2, which is a granular powder of m. (4) Aluminum alloy filler has a diameter of 150 to 3000μ
The composition according to claim 2, which is a flaky powder having a thickness of 1 to 100 μm. (5) The composition according to claim 2, wherein the aluminum alloy filler is a fiber having a diameter of 10 to 500 μm and a length of 500 to 30,000 μm. (6) The composition according to any one of claims 1 to 5, which contains 10 to 40% by volume of an aluminum alloy filler.