JPH05131445A - Conductive resin, manufacture thereof and conductive molded product - Google Patents

Abstract

PURPOSE:To provide conductive resin which can control freely a degree of electric conductivity to be provided by the conductive resin and is capable of providing the stabilized electric conductivity. CONSTITUTION:In conductive resin which is obtained by compounding a conductive compounding material into nonconductive resin, the conductive compounding material is comprised by a method wherein a respective short fiber body and powdery body whose surfaces are formed of a high-melting metal having the melting point higher than the molding temperature at the time of molding of the nonconductive resin are covered with a low-melting metal which has the low melting point than the molding temperature of nonconductive resin and is a solid body at the normal temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive resin, a method for manufacturing the same, and a conductive molded article, and more specifically, a conductive resin in which a conductive compounding material is mixed in a non-conductive resin, and a method for manufacturing the same. The present invention relates to a conductive molded product.

[0002]

2. Description of the Related Art In recent years, with the rapid spread of electronic equipment and the use of resin for housing housing electronic equipment, electromagnetic waves (noise) generated outside the electronic equipment cause malfunction of the electronic equipment, so-called radio interference frequently occurs. It started to come. As a means for preventing such radio interference, it is one of effective means to form a housing for housing an electronic device with a conductive resin. As such a conductive resin, the inventors of the present invention previously reported that, in Japanese Patent Application Nos. 2-307620 and 3-159717, a conductive compound made of metal in a non-conductive resin is used. We have proposed a conductive resin containing a material. This conductive compounding material has a short fibrous body or powder whose surface is formed by a high melting point metal having a higher melting point than the molding temperature at the time of molding the non-conductive resin from the molding temperature of the non-conductive resin. Is a conductive compound material having a low melting point and covered with a low melting point metal that is solid at room temperature.

[0003]

Two of the present inventors have proposed the above-mentioned conductive resin by melt molding,
A molded product exhibiting excellent conductivity can be obtained. Yui,
If the conductivity of the finally obtained conductive molded product is controlled by adjusting the blending amount of the conductive compounded material into the non-conductive resin, it will be difficult to control the conductivity of the obtained molded product itself. It has been found that, in some cases, the variation in conductivity exhibited between molded products and / or within molded products may increase. Therefore, the present inventors provide a conductive resin capable of freely controlling the degree of conductivity exhibited by the conductive resin and exhibiting stable conductivity, a method for producing the same, and a conductive molded article. is there.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted studies to achieve the above-mentioned object, and as a conductive compounding material, a short metal fibrous body previously covered with a low melting point metal and a metal powder were used in combination. It was found that the conductivity exhibited by the conductive resin can be freely controlled by changing the ratio of the metal short fibrous body and the metal powder while keeping the compounding amount of the conductive compounding material constant. .. That is, the present invention is a conductive resin in which a conductive compounding material is mixed in a non-conductive resin, wherein the conductive compounding material has a high melting point higher than the molding temperature at the time of molding the non-conductive resin. Each of the short fibrous body and the powdery body having a surface formed of a melting point metal is covered with a low melting point metal which has a melting point lower than the molding temperature of the non-conductive resin and is solid at room temperature. It is a conductive resin. Further, the present invention, the molding temperature of the non-conductive resin and the short fiber body and the powdery body whose surface is formed by the high melting point metal having a higher melting point than the molding temperature at the time of molding the non-conductive resin to be blended And a low melting point metal that is solid at room temperature, in the presence of a flux that prevents the formation of an oxide film on the surface of each metal of the short fibrous substance and the powdery substance, or in a substantially non-oxygen state, Kneading while heating to a temperature not lower than the melting point of the high melting point metal and not higher than the melting point of the high melting point metal to obtain a conductive compounding material in which each metal surface of the short fibrous body and the powdery material is covered with a low melting point metal, and then, A method for producing a conductive resin is characterized in that a conductive compounding material is added to a non-conductive resin and kneaded.

Furthermore, the present invention comprises a short fibrous body and a powdery body which form a surface of a refractory metal having a melting point higher than the molding temperature at the time of molding a non-conductive resin. And a conductive compounding material in which each metal surface of the powdery material has a melting point lower than the molding temperature of the non-conductive resin and is covered with a low-melting point metal that is solid at room temperature, It is also a conductive molded product, which is a molded product obtained by melt-molding a volatile resin. In the present invention, the high melting point metal forming each surface of the short fibrous body and the powdery body is copper and the low melting point metal is solder, and the low melting point metal causes the short fibrous body and the powdery body to be The metal surface can be easily covered. Further, when the blending weight ratio of the conductive compounding material to the non-conductive resin (total conductive compounding material / non-conductive resin) is 1 or more, the conductivity of the obtained conductive molded article is further stabilized. ..

[0006]

[Function] In a conductive resin in which a short fiber-like or powder-like conductive compounding material is solely mixed in a non-conductive resin,
When a predetermined amount or more of the conductive compounding material is mixed in the non-conductive resin, the conductive resin can exhibit stable conductivity even if the compounding amount of the conductive compounding material is slightly changed. But,
When the blending amount of the short fibrous conductive compounding material or the powdery conductive compounding agent is less than a predetermined amount, the conductivity of the obtained conductive resin becomes unstable. Therefore, when controlling the degree of conductivity exhibited by the conductive resin by adjusting the blending amount of the conductive compounding agent, when the compounding amount of the conductive compounding agent reaches an unstable region, the conductive resin is It is difficult to control the conductivity exhibited by the conductive molded product obtained by melt molding. In this respect, according to the present invention, the conductive resin maintains the compounding amount of the conductive compounding material capable of exhibiting stable conductivity, and the mixing ratio of the short fibrous conductive compounding material and the powdery conductive compounding material is Since the degree of conductivity exhibited by the conductive resin can be freely controlled by changing the amount, the conductive resin can exhibit stable conductivity even if the compounding amount of the conductive compounding material slightly changes.

[0007]

In the present invention, it is important that a short fiber-like conductive compounding material and a powdery conductive compounding material are used in combination as the conductive compounding material mixed in the non-conductive resin.
Such short fibrous conductive compounding material and powdery conductive compounding material,
A short fibrous body formed of a refractory metal having a melting point higher than the molding temperature when molding the non-conductive resin to be blended (hereinafter, may be simply referred to as a metal single fiber) and a powdery body (hereinafter, (Sometimes referred to as metal powder), each surface is covered with a low-melting metal that has a melting point lower than the molding temperature and is solid at room temperature.

Examples of the metal short fibers and metal powders whose surfaces are formed of such high melting point metals are copper (Cu) and nickel.
Metal short consisting of a single metal such as (Ni), iron (Fe), zinc (Zn), aluminum (Al), lead (Pb), nickel (Ni) -chromium (Cr) alloy, tungsten (W), brass Fibers can be used. Further, different kinds of metals may be attached to the surface of the metal short fibers by plating or the like. In addition, carbon, glass,
Even for short fibers made of non-metals such as ceramics, the surface of the short fibers is copper (Cu), nickel by electroless plating, etc.
It may be covered with a refractory metal such as (Ni). The thickness and length of the metal short fibers used in the present invention can be arbitrarily determined in consideration of the characteristics such as the viscosity of the non-conductive resin to be blended and the molding performance, etc.
Short metal fibers having a thickness of 5 to 100 μm and a length of about 2 to 10 mm are used. As the metal powder, as in the case of the metal short fibers, it can be arbitrarily determined in consideration of the characteristics such as the viscosity of the non-conductive resin to be blended, the molding performance, etc., but usually 100 mesh or less is preferable. For 200
The following mesh is used.

The metal surfaces of such short metal fibers and metal powders are covered with a low melting point metal. It is presumed that the low melting point metal is dispersed in the resin to form a conductive network structure together with the metal short fibers and the metal powder. The low-melting point metal may be any metal that is a solid below the melting point of the resin to be blended and at room temperature, such as zinc (Zn), lead (Pn
Examples thereof include b), tin (Sn), and solder. Among them, solder is particularly preferable. When solder is used as the low melting point metal, it is necessary to use a composition having a desired melting point in relation to the resin to be mixed.

The amount of the low melting point metal attached to the short metal fibers is such that the coating thickness of the low melting point metal covering the short metal fibers is 0.7 to 9 μm, more preferably 2.5 to 5 μm (particularly preferably 3. It is preferable that the amount is 5 to 4 μm) in order to impart sufficient conductivity to the obtained molded product. Here, the coating thickness of the low melting point metal is 0.7 μm.
When it is less than m, there is a portion of the surface of the short metal fibers which is not covered with the low melting point metal, so that it tends to be difficult to impart sufficient conductivity to the finally obtained molded product. In this respect, when the film thickness of the low melting point metal is 0.7 μm or more,
Since the surface of the short metal fibers is completely covered with the low melting point metal, it is possible to impart sufficient conductivity to the finally obtained molded product. On the other hand, even if a conductive compounding material having a coating thickness of the low melting point metal that coats the metal short fibers exceeds 9 μm, there is a tendency that the improvement in the conductivity of the obtained conductive molded article tends to be small, so that the low melting point The upper limit of metal film thickness is 9μ
It is preferably m. The ratio of the metal short fibers to the low melting point metal varies depending on factors such as the thickness of the metal short fibers. For example, for copper short fibers having a thickness of 50 μm and an average length of 5 mm, the coating thickness of the solder is When setting to 0.7 μm,
It can be obtained by adding 5 parts by weight of solder to 100 parts by weight of copper short fibers and kneading.

The amount of the low melting point metal attached to the metal powder is preferably such that the weight ratio of metal powder / low melting point metal is 1/2 or more, and particularly 1 / 2.5 or more. If the weight ratio of the metal powder / low melting point metal is less than 1/2, it tends to be difficult to sufficiently impart conductivity to the non-conductive resin.
On the other hand, if the weight ratio of the low melting point metals is too high, the molten low melting point metals will be in an aggregated state. The upper limit of the weight ratio varies depending on the type of metal powder, the size such as the particle size, the surface characteristics, the type of low melting point metal, and the like, so it is preferable to experimentally determine in advance.

The compounding amount of the fibrous conductive compounding material and the powdery conductive compounding material composed of such a metal short fiber and a low melting point metal to the non-conductive resin is the total conductive compounding material / non-conductive material. By setting the compounding weight ratio of the resin to 1 or more, particularly 1.5 or more, it is possible to obtain a conductive resin exhibiting stable conductivity even if the compounding amount of the conductive compounding material changes to some extent. When the blending weight ratio is less than 1, the electroconductivity of the electroconductive resin obtained tends to be unstable. The upper limit of the blending amount varies depending on the thickness of the metal short fibers, the particle size of the metal powder, etc., and it is possible to find the upper limit of the blending amount of the conductive compounding material in the short metal fibers and the metal powder to be adopted in advance. preferable.

The conductive compounding material used in the present invention is a short metal fiber and / or a metal powder whose surface is formed of a high melting point metal having a melting point higher than the molding temperature at which the non-conductive resin to be mixed is molded. Hereinafter, sometimes referred to as short metal fibers, etc.) and a low melting point metal having a melting point lower than the forming temperature and solid at room temperature in the presence of a flux that prevents the formation of an oxide film on the surface of the high melting point metal. By kneading while heating to a temperature not lower than the melting point of the low melting point metal and lower than the melting point of the high melting point metal, the surface of the high melting point metal can be covered with the low melting point metal. Here, even when kneading metal short fibers or the like having an oxide film formed on the surface of the high-melting point metal, the wettability between the melt of the low-melting point metal and the surface of the high-melting point metal is insufficient. Therefore, the surface of the refractory metal cannot be sufficiently covered. In order to prevent the formation of such an oxide film and the like, in the present invention, the metal short fibers and the like and the low melting point metal are kneaded in the presence of flux or in the absence of flux without the presence of flux. At this time, as the flux to be used, a zinc chloride flux conventionally used, a rosin flux used in JP-A-63-218310, or the like can be used.

As a method for producing a conductive compound material using a flux, a method of previously kneading metal short fibers and the flux and then adding a low-melting point metal and heating to knead the low-melting point metal while melting, It is possible to adopt a method of adding flux to a low-melting metal that has been melted in advance, and then kneading by adding short metal fibers or the like, or a method of heating while simultaneously kneading low-melting metal and flux, such as short metal fibers and the like. it can. The heating temperature at this time is equal to or higher than the melting point of the low melting point metal,
It is necessary that the melting point be lower than the melting point of the high melting point metal that forms the surface of the short metal fibers or the like. In such a manufacturing method, when the surface of the high melting point metal such as short metal fibers is not visible during kneading, it can be determined that the surface of the high melting point metal is covered with the molten low melting point metal. After that, the conductive compound material obtained by cooling and solidifying the low melting point metal is dispersed and then washed to remove the flux remaining in the low melting point metal. By performing such cleaning, the flux mixed in the non-conductive resin can be reduced as much as possible. The kneading of the short metal fibers and the low melting point metal in the presence of such a flux can be carried out in the atmosphere, but since it is necessary to allow the flux to exist, the obtained conductive compounding material is washed. Even if the residual flux is removed, it is difficult to completely remove it. In this respect, if the kneading of the low melting point metal and the metal short fibers is carried out under substantially non-oxygen condition, the conductive compounding material can be mixed in the resin without any flux. Such kneading under non-oxygen can be carried out at a heating temperature lower than that in the atmosphere in the presence of flux, and the heating temperature is not higher than the melting point of the low melting point metal [preferably (melting point of the low melting point metal -10 ° C.) or higher].
Here, "substantially in non-oxygen state" means that kneading is performed under a high vacuum of 5 mmHg or less, or under a nitrogen or hydrogen atmosphere.

The conductive compound material thus obtained can be mixed with the non-conductive resin by adding the conductive compound material to the melted non-conductive resin and kneading. .. Such kneading, at the time of injection molding, may be kneaded by a screw rotating a non-conductive resin and a conductive compounding material supplied into the injection cylinder of an injection molding machine,
Alternatively, both may be kneaded using a kneader such as a twin-screw ruder. During kneading, the order of introducing the conductive compounding material after adding the resin may be simultaneous addition or sequential addition of the short fiber conductive compounding material and the powdery conductive compounding material. Good. The obtained conductive resin can be molded by melt molding. As such melt molding, an injection molding method in which a conductive resin mixed with a desired conductive compounding material is injection-molded by an injection molding machine, or a master chip prepared by previously compounding a conductive compounding material in high concentration in a resin There is a master chip method in which a conductive resin and a melt molding machine such as an injection molding machine are supplied and melt-molded. Examples of the non-conductive resin with which the conductive compounding material is blended in the present invention include non-conductive resins that have been conventionally used, such as polypropylene, nylon, polyester, polyethylene, ABS resin, polycarbonate, and polyacetal. .. Among such non-conductive resins, resins such as polyacetal and polycarbonate are feared to be decomposed due to the zinc chloride-based flux, so that zinc chloride-based flux is used in the production of the conductive compound material. When the conductive compounding material is mixed, it is preferable to thoroughly wash the flux to reduce the flux mixed in the resin through the conductive compounding material as much as possible.

The conductive molded product obtained by the melt molding as described above can exhibit good conductivity, and the detailed reason thereof has not been clarified yet, but it can be inferred as follows.
That is, when the molten conductive resin is filled in the cavity of the mold, the short metal fibers or the like are oriented in the flowing direction of the molten resin. At the same time, the low melting point metal covering the surfaces of the metal short fibers and the metal powder is melted, and the joint points of the oriented metal short fibers are fused together, and the metal is dispersed while flowing as the resin flows. This is because short fibers can be connected to each other to form a metal stitch structure in the resin. This means that when using a conductive compounding material in which a large amount of a low melting point metal is attached to short metal fibers or the like, when observing the cross section of the obtained conductive resin with a microscope, in a cross section parallel to the flow direction of the resin, It can be observed that the low-melting-point metal is flowing and diffused while flowing in the resin flow direction. Since such a conductive molded article can exhibit excellent conductivity, it can be used for electromagnetic wave shielding, X-ray shielding, and parabolic antenna. When the parabolic antenna is molded using the conductive resin of the present invention, the parabolic antenna can be integrally molded including the fitting for mounting the parabolic antenna. Furthermore, since the conductive molded article of the present invention generates heat when energized, it can also be used as a heating element, and can be used for a snow melting device such as a parabolic antenna or a defroster for an electric refrigerator. In addition, since the surface of the molded product can be directly soldered, the ground terminal can be directly soldered to the case. At this time, the influence of the solder heat is substantially limited only to the soldering portion, and the means for protecting the components and the like arranged in other portions from the solder heat can be eliminated. The conductive molded article of the present invention is a composite molded article composed of a core component in which the conductive resin of the present invention is arranged in the central portion and a sheath component in which a non-conductive resin is arranged around the core component. Good as an item.

[0017]

EXAMPLES The present invention will be described in more detail by way of examples. (1) Preparation of conductive compound material Short fibrous conductive compound material A short copper fiber having a diameter of 50 μm and an average length of 5 mm is mixed with a zinc chloride-based flux (0.2 g per 1 g of copper short fiber). Weight ratio to fiber (solder / copper short fiber) is 0.3
An amount of solder (Sn-Pb) having a melting point of 183 ° C. was added. Next, while the solder added in advance was heated to a melting temperature (about 200 ° C.) and kneaded until the copper color completely disappeared, the solder was cooled and solidified and dispersed, and then the flux was washed. In the obtained conductive compound material, the surface of the copper short fibers was completely covered with solder. Powdery conductive compounding material A mixture of copper powder that passes through a 200-mesh net and zinc chloride-based flux (0.2 g per 1 g of copper short fiber), and the weight ratio (solder / copper short fiber) to copper short fiber is An amount of solder (Sn-Pb) having a melting point of 183 ° C. was added. Next, the temperature at which the previously added solder melts (about 200 ° C)
The mixture was kneaded while heating to 100 ° C. until the copper color completely disappeared, the solder was cooled and solidified and dispersed, and then the flux was washed. In the obtained conductive compound material, the surface of the copper powder was completely covered with solder.

(2) Molding The obtained conductive compounding material was compounded in ABS resin and injection molding was carried out to obtain a rectangular plate-shaped body. Such injection molding
The conductive compound material was previously blended into the ABS resin at a concentration of about 8 times higher than that of the ABS resin to form chips. Then
The obtained master chip was injection molded by an injection molding machine. The injection mold is a center direct gate system. At this time, the total volume of the conductive compounding material and the volume resistance value of the molded product obtained by variously changing the compounding weight ratio of the short fibrous electrically conductive compounding material and the powdery electrically conductive compounding material are obtained. The results are shown in Fig. 1. The curves in FIG. 1 are of the following levels. Curve 10: Only short fibrous conductive compounding material is compounded (no powdery electrically conductive compounding material is compounded) Curve 12 to curve 18: Blending weight ratio of ABS resin and short fibrous electrically conductive compounding material is kept constant (ABS Change the blending weight ratio of the resin and the powdery conductive compounding material) Curve 12: Short fiber conductive compounding material / ABS resin = 1.5 Curve 14: Short fiber conductive compounding material / ABS resin = 1.0 Curve 16: Short fiber conductive compound / ABS resin = 0.6 Curve 18: Short fiber conductive compound / ABS resin = 0.4
5 Curve 20: No short fibrous conductive compound added (only powder conductive compound added)

As is clear from FIG. 1, at the levels of the curves 10 and 20, in order to control the conductivity exhibited by the obtained molded product, the short fiber conductive compound or the powdery conductive compound to be blended is used. It is necessary to adjust the compounding amount of the compounding material. In this case, the compounding weight ratio of the conductive compounding material to the ABS resin capable of adjusting the conductivity exhibited by the obtained molded product is as follows: at the level of curve 10, the compounding weight ratio of the short fiber conductive compounding material / ABS resin is 1 Less than and curve 2
At a level of 0, the compounding weight ratio of powdery conductive compounding material / ABS resin is less than 4. However, when the compounding weight ratio is less than 1 at the level of the curve 10 and less than 4 at the level of the curve 20, the volume resistance value of the conductive resin obtained by a slight change in the compounding amount of the conductive compounding material is significantly changed. It is an unstable region. Therefore, curve 10 and curve 2
At a level of 0, the electroconductivity of the electroconductive resin obtained is extremely unstable.

In this respect, at the levels of curves 12 to 18, the volume resistance value of the obtained conductive resin is in the middle of the volume resistance value of the conductive resin obtained at the level of curve 10 or curve 20. The volume resistance value of the obtained conductive resin can be freely changed by changing the mixing ratio of the short fiber conductive compound and the powdery conductive compound. Further, even if the compounding amount of the conductive compounding material is slightly changed, the stable region where the volume resistance value of the obtained molded product is stable is within the unstable region of the curve 20 (powdered conductive compounding material / ABS). Resin is present below 4). Therefore, in the levels of the curves 12 to 18, the total blending amount of the conductive compounding material is changed by changing the compounding weight ratio of the short fibrous conductive compounding material and the powdery conductive compounding material in the stable region. The volume resistance value of the obtained molded product can be easily controlled without changing, and a molded product exhibiting a constant conductivity can be obtained even if the total amount of the conductive compounding material changes to some extent. Therefore, according to this example, by changing the compounding ratio of the short fibrous conductive compounding material and the powdery conductive compounding material, the total compounding amount of the electrically conductive compounding material compounded to the ABS resin is kept constant. It is possible to easily obtain a conductive resin exhibiting conductivity suitable for the intended use of the molded product that is finally obtained while holding the above.

[0021]

According to the present invention, an X-ray shield for X-rays is provided.
It is possible to easily obtain a conductive resin suitable for the purpose of use of the conductive molded product such as a wire shield and a parabolic antenna. In addition, since the conductive molded product obtained by the present invention has a property of generating heat when energized, it can be used as a defroster for an electric refrigerator. Further, the case of the electric product can be directly grounded to the case by molding the case with a conductive resin.

[Brief description of drawings]

[Figure 1] Compounding weight ratio of conductive compounding material (total conductive compounding material /
Is a graph showing the relationship between the non-conductive resin), and the conductivity of the conductive molded product of the molded product obtained by variously changing the compounding ratio of the short fibrous conductive compounding material and the powdery conductive compounding material. ..

[Explanation of symbols]

10 A curve showing the relationship between the conductivity of the conductive resin obtained by blending only the short fibrous conductive compounding material with the non-conductive resin and the blending amount of the short fibrous conductive compounding material 12 Short fibrous conductivity Compounding material / conductivity of electroconductive resin obtained by keeping the non-conducting resin at 1.5 and changing the compounding weight ratio of non-conducting resin and powdery conducting compounding material Curve 14 showing the relationship with the compounding amount of the short fibrous conductive compounding material / non-conductive resin is maintained at 1.0, and the compounding weight ratio of the non-conductive resin and the powdery conductive compounding material is changed. A curve showing the relationship between the conductivity of the obtained conductive resin and the blending amount of the total conductive blending material. 16 A short fibrous conductive blending material / non-conductive resin was held at 0.6 and A curve showing the relationship between the conductivity of the conductive resin obtained by changing the compounding weight ratio with the powdery conductive compounding material and the compounding amount of the total electrically conductive compounding material 8 short fibrous conductive compounding material / non-conductive resin 0.45
A curve showing the relationship between the conductivity of the conductive resin and the compounding amount of the total conductive compounding material obtained by changing the compounding weight ratio of the non-conductive resin and the powdery conductive compounding material. Curve showing the relationship between the conductivity of the conductive resin obtained by mixing only the conductive conductive compound with the non-conductive resin and the compounding amount of the powdery conductive compound

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Claims (9)

[Claims] 1. A conductive resin in which a conductive compounding material is mixed in a non-conductive resin, wherein the conductive compounding material has a higher melting point than the molding temperature at which the non-conductive resin is molded. A conductive material characterized in that each of a short fibrous body and a powdery body having a surface formed of a metal is covered with a low melting point metal which has a melting point lower than the molding temperature of the non-conductive resin and is solid at room temperature. Resin. 2. The conductive resin according to claim 1, wherein the high melting point metal forming each surface of the short fibrous body and the powdery body is copper and the low melting point metal is solder. 3. The conductive resin according to claim 1, wherein the compounding weight ratio of the non-conductive compounding material to the non-conductive resin (total conductive compounding material / non-conductive resin) is 1 or more. 4. A temperature below the molding temperature of the non-conductive resin and the short fibrous bodies and powders having a surface formed of a high melting point metal having a melting point higher than the molding temperature at the time of molding the non-conductive resin to be blended. And a low melting point metal that is solid at room temperature, in the presence of a flux that prevents the formation of an oxide film on each metal surface of the short fibrous body and the powdery body, or in a substantially non-oxygen state, Kneading while heating to a temperature not lower than the melting point and not higher than the melting point of the high melting point metal to obtain a conductive compound material in which each metal surface of the short fibrous body and the powdery material is covered with a low melting point metal, and then the conductive material A method for producing a conductive resin, comprising adding a conductive compounding material to a non-conductive resin and kneading. 5. The method for producing a conductive resin according to claim 4, wherein the high melting point metal forming the surface of the short fibrous body and the powdery body is copper and the low melting point metal is solder. 6. The method for producing a conductive resin according to claim 4, wherein a blending weight ratio of the conductive blending material to the non-conductive resin (total conductive blending material / non-conductive resin) is 1 or more. 7. A conductive molded product, which is a molded product obtained by melt-molding a conductive resin obtained by mixing the conductive compounding material according to claim 1 in a non-conductive resin. 8. The electrically conductive molded article according to claim 7, wherein the high melting point metal forming the surface of the short fibrous body is copper and the low melting point metal is solder. 9. The electroconductive molded article according to claim 7, wherein the compounding weight ratio of the electroconductive compounding material to the nonelectroconductive resin (total electroconductive compounding material / nonelectroconductive resin) is 1 or more.