JP2007092074A - Electroconductive polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make electroconductivity of a polymer more adjustable to a desired state. <P>SOLUTION: This electroconductive polymer contains a polymer and a conductivity-adjusting material added to the polymer. The conductivity-adjusting material contains a first group of fibrils consisting of a first carbon short fiber and a second group of fibrils consisting of a second carbon short fiber having a smaller average fiber diameter than that of the first carbon short fiber. The first group of fibrils has a larger fibril group electric resistance value than that of the second group of fibrils. The fibril group electric resistance value of the first group of fibrils is not less than 1 Ωcm and not more than 100 kΩcm, for example. The fibril group electric resistance value of the second group of fibrils is not less than 0.001 Ωcm and less than 1 Ωcm, for example. The content of the conductivity-adjusting material is 5-40 wt.%, for example. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a conductivity adjusting material and a polymer material, and particularly to a conductivity adjusting material for adjusting the conductivity of the polymer material and a polymer material having conductivity.

  Polymer materials such as resins are widely used in the field of electric and electronic parts because they generally exhibit excellent electrical insulation. However, electrical / electronic component materials made of polymer materials themselves are generally electrically charged because of their electrical insulation properties, and have problems such as damage to electronic components such as ICs due to dust adhesion or discharge. For this reason, the polymer material used in the semiconductor manufacturing field is usually given a weak conductivity by adding a conductive material.

Incidentally, carbon black is widely known as a conductive material for imparting conductivity to a polymer material. However, since carbon black, particularly acetylene black and ketjen black, are powders that exhibit high conductivity, it is difficult to gradually and gradually adjust the conductivity of the polymer material. In other words, carbon black changes the conductivity of the polymer material abruptly (for example, in the range of about 10 ⁹ ) by changing the addition amount slightly, and the conductivity of the polymer material is subtly changed. It is inappropriate to change. For this reason, when carbon black is used as a conductive material, the conductivity that is often required for polymer materials used in the field of electronic components, that is, the weak conductivity of about 10 ⁵ to 10 ¹³ Ωcm is stable. Is difficult to apply. In addition, since carbon black is a powder as described above, it is not easy to handle, and also tends to cause poor dispersion when added to a polymer material, and may cause contamination due to falling off from the molded body. is there.

  In addition, carbon fibers that are unlikely to cause contamination are being used as conductive materials instead of carbon black. For example, Patent Document 1 describes a polymer material imparted with conductivity by ultrafine carbon fibers. However, since these carbon fibers are also highly conductive materials, it is extremely difficult to finely adjust the conductivity of the polymer material as in the case of carbon black and set it within the above range.

Japanese Patent Laid-Open No. 2-300263

  An object of the present invention is to make it easy to adjust the conductivity of a polymer material to a desired state.

  The conductivity adjusting material for a polymer material of the present invention is for adjusting the conductivity of the polymer material. The first fiber group is composed of first carbon short fibers, and the average fiber diameter is larger than that of the first carbon short fibers. Includes a second fiber group of small second carbon short fibers. The first fiber group has a smaller fiber group electrical resistance value than the second fiber group.

  Here, each of the first carbon short fibers and the second carbon short fibers has an average aspect ratio of, for example, 5 to 2,000. Further, the ratio (A / B) of the average fiber diameter (A) of the first short carbon fibers and the average fiber diameter (B) of the second short carbon fibers is, for example, at least 1.5.

  The first fiber group and the second fiber group both have a fiber group electrical resistance value of at least 1 Ωcm, for example. Alternatively, both the first fiber group and the second fiber group have a fiber group electrical resistance value of, for example, 0.001 Ωcm or more and less than 1 Ωcm. Alternatively, the fiber group electrical resistance value of the first fiber group is, for example, 0.001 Ωcm or more and less than 1 Ωcm, and the fiber group electrical resistance value of the second fiber group is, for example, 1 Ωcm or more and 100 kΩcm or less.

  Furthermore, the weight ratio of the first fiber group is set larger than the weight ratio of the second fiber group, for example. Alternatively, the weight ratio of the first fiber group is, for example, 50% by weight or more and less than 99.9% by weight, and the weight ratio of the second fiber group is, for example, 50% by weight or less and 0.1% by weight or more.

  The conductivity adjusting material for a polymer material according to another aspect of the present invention is for adjusting the conductivity of the polymer material, and includes a first fiber group of first carbon short fibers and a first carbon short fiber. 2nd fiber group by the 2nd carbon short fiber whose average fiber diameter is smaller than this. The first fiber group has a larger fiber group electrical resistance value than the second fiber group.

  Here, each of the first carbon short fibers and the second carbon short fibers has an average aspect ratio of, for example, 5 to 2,000. Further, the ratio (A / B) of the average fiber diameter (A) of the first short carbon fibers and the average fiber diameter (B) of the second short carbon fibers is, for example, at least 1.5.

  The first fiber group and the second fiber group both have a fiber group electrical resistance value of at least 1 Ωcm, for example. Alternatively, both the first fiber group and the second fiber group have a fiber group electrical resistance value of, for example, 0.001 Ωcm or more and less than 1 Ωcm. Alternatively, the fiber group electrical resistance value of the first fiber group is, for example, 1 Ωcm or more and 100 kΩcm or less, and the fiber group electrical resistance value of the second fiber group is, for example, 0.001 Ωcm or more and less than 1 Ωcm.

  Furthermore, the weight ratio of the first fiber group is set larger than the weight ratio of the second fiber group, for example. Alternatively, the weight ratio of the first fiber group is, for example, 50% by weight or more and less than 99.9% by weight, and the weight ratio of the second fiber group is, for example, 50% by weight or less and 0.1% by weight or more.

  The conductivity adjusting material for a polymer material according to still another aspect of the present invention is for adjusting the conductivity of the polymer material, and includes a first fiber group of first carbon short fibers and a first carbon short. 2nd fiber group by the 2nd carbon short fiber whose average fiber diameter is smaller than a fiber.

  Here, each of the first fiber group and the second fiber group has a fiber group electrical resistance value of at least 1 Ωcm, for example. Alternatively, both the first fiber group and the second fiber group have a fiber group electrical resistance value of, for example, 0.001 Ωcm or more and less than 1 Ωcm.

  The conductive polymer material according to the present invention includes a polymer material and a conductivity adjusting material added to the polymer material. The conductivity adjusting material includes a first fiber group composed of first carbon short fibers, and a second fiber group composed of second carbon short fibers having an average fiber diameter smaller than that of the first carbon short fibers. The fiber group electrical resistance value is smaller than that of the second fiber group. Here, the content of the conductivity adjusting material is, for example, 5 to 40% by weight.

  A conductive polymer material according to another aspect of the present invention includes a polymer material and a conductivity adjusting material added to the polymer material. The conductivity adjusting material includes a first fiber group composed of first carbon short fibers, and a second fiber group composed of second carbon short fibers having an average fiber diameter smaller than that of the first carbon short fibers. The fiber group electrical resistance value is larger than that of the second fiber group. Here, the content of the conductivity adjusting material is, for example, 5 to 40% by weight.

  Since the conductivity adjusting material for a polymer material according to the present invention includes the first fiber group and the second fiber group as described above, the conductivity of the polymer material is changed stepwise when the amount of addition to the polymer material is changed. It is easy to adjust the conductivity of the polymer material as compared with the conventional conductivity adjusting material. In addition, the conductivity adjusting material of the present invention changes the ratio of the first fiber group and the second fiber group while setting the amount of addition to the polymer material to the minimum necessary amount, and the conductivity of the polymer material is changed. Can be gradually changed step by step.

  On the other hand, since the conductive polymer material of the present invention includes the conductivity adjusting material according to the present invention, the conductivity is easily set in a desired range.

Conductivity adjusting material for polymer material The conductivity adjusting material for polymer material according to the present invention includes two fiber groups, a first fiber group and a second fiber group. Here, the first fiber group is composed of a large number of first carbon short fibers, and the second fiber group is composed of a large number of second carbon short fibers.

  The first carbon short fibers and the second carbon short fibers are all known short fibers of various carbon fibers, such as polyacrylonitrile-based carbon fibers, isotropic pitch-based carbon fibers, and anisotropic pitch-based carbon fibers. And quinol resin-based carbon fiber, rayon-based carbon fiber, and lignin-based carbon fiber. Two or more of these carbon fibers may be used in combination in the first fiber group and the second fiber group. In addition, the firing temperature of these carbon fibers is not particularly limited, but is appropriately set in relation to the fiber group electrical resistance value described later. That is, when a relatively high fiber group electrical resistance value is required, the firing temperature is set relatively low, and when a relatively low fiber group electrical resistance value is required, the firing temperature is relatively high. Set to

  The average fiber length of the first carbon short fiber and the second carbon short fiber is not particularly limited as long as it is generally recognized as a short fiber, but is usually 0.1 to 30 mm, preferably 0.5. 10 mm, more preferably about 0.7 to 6 mm. When the average fiber length is less than 0.1 mm, it may be difficult to develop conductivity. On the contrary, when it exceeds 30 mm, there is a possibility that the supply becomes difficult when mixing (compositing) with the polymer material. In addition, the average fiber length here is a value that can be obtained by an optical microscope (SEM).

  The average aspect ratio (average fiber length / average fiber diameter) of the first carbon short fibers and the second carbon short fibers is usually preferably set to 5 to 2,000, and preferably set to 10 to 1,800. More preferably, it is more preferably set to 20 to 1,500. If the average aspect ratio is less than 5, the effect of reducing the electrical resistance to the polymer material may be reduced. On the other hand, when it exceeds 2,000, there is a risk that it is difficult to quantitatively supply the polymer material. The average aspect ratio is preferably as long as it can be quantitatively supplied because the remaining aspect ratio after being combined with the polymer material can be increased. Incidentally, the average fiber diameter which becomes the standard of this average aspect ratio is a value which can be obtained by an optical microscope (SEM).

  However, the second short carbon fibers constituting the second fiber group used in the present invention need to have a smaller average fiber diameter than the first short carbon fibers constituting the first fiber group. In other words, the average fiber diameter of the first short carbon fibers needs to be set larger than the average fiber diameter of the second short carbon fibers. For example, the ratio (A / B) of the average fiber diameter (A) of the first short carbon fibers to the average fiber diameter (B) of the second short carbon fibers is preferably at least 1.5, and at least 2. More preferably 0. When this ratio is less than 1.5, when the conductivity adjusting material of the present invention is combined with the polymer material, the conductivity of the polymer material changes significantly with a slight change in the amount added. As a result, it may be difficult to adjust the conductivity of the polymer material to a desired state.

Each of the first fiber group and the second fiber group used in the present invention has a fiber group electrical resistance value described later of at least 1 Ωcm (preferably at least 1.1 Ωcm), or both have a fiber group electrical resistance value. It is desirable that it is 0.001 Ωcm or more and less than 1 Ωcm (preferably 0.01 Ωcm or more and less than 0.5 Ωcm). In the former case, the conductivity of the polymer material can be easily adjusted to a desired state within a small range (that is, a range where the electrical resistance is large, for example, a range of 10 ¹⁰ to 10 ¹³ Ωcm). On the other hand, in the latter case, the conductivity of the polymer material can be easily adjusted to a desired state within a large range (that is, a range where the electrical resistance is small, for example, a range of 10 ⁵ to 10 ¹⁰ Ωcm).

Here, the fiber group electrical resistance value is not the electrical resistance value of individual carbon short fibers constituting the fiber group, but the electrical resistance value of the entire fiber group composed of a number of carbon short fibers, and is as follows. Is required. First, an electrical insulator having a through hole with a diameter of 0.8 cm is prepared at the center, and one end of the through hole is sealed with an electrode. Then, 0.5 g of the fiber group is filled in the through hole, a conductive push rod is inserted from the other end of the through hole, and a pressure of 40 kgf / cm ² is applied to make the fiber group into a column having a height of xcm. Mold. In this state, a tester is connected between the electrode and the push rod, and the electrical resistance value of the fiber group compressed in the through hole is measured. The fiber group electrical resistance value is obtained by multiplying the measured electrical resistance value by the area of the end face of the molded body of the fiber group (that is, 0.4 ² πcm ² ) and dividing the value by the height xcm, the volume resistance value (Ωcm ). In addition, the tester used when measuring the electrical resistance value of the fiber group is usually one that can directly measure resistance such as a digital multimeter.

  Further, the first fiber group and the second fiber group used in the present invention may have different fiber group electrical resistance values. That is, the fiber group electrical resistance value of the first fiber group and the fiber group electrical resistance value of the second fiber group may be different. In this case, the conductivity adjusting material for a polymer material of the present invention can be described in the following two aspects.

(Aspect 1)
In this aspect, the fiber group electrical resistance value of the first fiber group is set smaller than the fiber group electrical resistance value of the second fiber group.
In the case of this aspect, the fiber group electrical resistance values of the first fiber group and the second fiber group are set as follows, for example.
(1) The fiber group electrical resistance values of the first fiber group and the second fiber group are both set to be at least 1 Ωcm, preferably at least 1.1 Ωcm. In other words, the fiber group electrical resistance value of the first fiber group and the second fiber group is at least 1 Ωcm (that is, 1 Ωcm or more), and the fiber group electrical resistance value of the first fiber group is the fiber group of the second fiber group. It is set smaller than the electric resistance value. In this case, the conductivity adjusting material of the present invention can easily set the conductivity of the polymer material to a desired state within a small range (that is, a range where the electrical resistance is large, for example, a range of 10 ¹⁰ to 10 ¹³ Ωcm). Can do.

(2) The fiber group electrical resistance values of the first fiber group and the second fiber group are both set to 0.001 Ωcm or more and less than 1 Ωcm, preferably 0.01 Ωcm or more and less than 1 Ωcm. In other words, the fiber group electrical resistance value of the first fiber group and the second fiber group is 0.001 Ωcm or more and less than 1 Ωcm, preferably 0.01 Ωcm or more and less than 1 Ωcm, and the fiber group electrical resistance value of the first fiber group is It is set smaller than the fiber group electrical resistance value of the second fiber group. In this case, the conductivity adjusting material of the present invention can easily set the conductivity of the polymer material to a desired state within a large range (that is, a range where the electrical resistance is small, for example, a range of 10 ⁵ to 10 ¹⁰ Ωcm). Can do.

(3) The fiber group electrical resistance value of the first fiber group is set to 0.001Ω or more and less than 1Ω (preferably 0.01Ω or more and less than 1Ω), and the fiber group electrical resistance value of the second fiber group is 1Ω or more and 100 kΩ. Or less (preferably 1Ω or more and 100Ω or less). When the fiber group electrical resistance value of the first fiber group is less than 0.001Ω or when the fiber group electrical resistance value of the second fiber group exceeds 100 kΩ, the addition amount of the conductivity adjusting material of the present invention to the polymer material is There is a possibility that the electrical resistance value of the polymer material hardly changes even if it is significantly changed, and in order to finely adjust the conductivity of the polymer material step by step, a large amount of the conductivity adjusting material of the present invention is required. There is a case.

(Aspect 2)
In this aspect, the fiber group electrical resistance value of the first fiber group is set larger than the fiber group electrical resistance value of the second fiber group.
In the case of this aspect, the fiber group electrical resistance values of the first fiber group and the second fiber group are set as follows, for example.
(1) The fiber group electrical resistance values of the first fiber group and the second fiber group are both set to be at least 1 Ωcm, preferably at least 1.1 Ωcm. In other words, the fiber group electrical resistance value of the first fiber group and the second fiber group is at least 1 Ωcm (that is, 1 Ωcm or more), and the fiber group electrical resistance value of the first fiber group is the fiber group of the second fiber group. It is set larger than the electric resistance value. In this case, the conductivity adjusting material of the present invention can easily set the conductivity of the polymer material to a desired state within a small range (that is, a range where the electrical resistance is large, for example, a range of 10 ¹⁰ to 10 ¹³ Ωcm). Can do.

(2) The fiber group electrical resistance values of the first fiber group and the second fiber group are both set to 0.001 Ωcm or more and less than 1 Ωcm, preferably 0.01 Ωcm or more and less than 1 Ωcm. In other words, the fiber group electrical resistance value of the first fiber group and the second fiber group is 0.001 Ωcm or more and less than 1 Ωcm, preferably 0.01 Ωcm or more and less than 1 Ωcm, and the fiber group electrical resistance value of the first fiber group is It is set larger than the fiber group electrical resistance value of the second fiber group. In this case, the conductivity adjusting material of the present invention can easily set the conductivity of the polymer material to a desired state within a large range (that is, a range where the electrical resistance is small, for example, a range of 10 ⁵ to 10 ¹⁰ Ωcm). Can do.

(3) The fiber group electrical resistance value of the first fiber group is set to 1Ω to 100 kΩ (preferably 1Ω to 100Ω), and the fiber group electrical resistance value of the second fiber group is 0.001Ω to less than 1Ω ( Preferably, it is set to 0.01Ω or more and less than 1Ω. When the fiber group electrical resistance value of the first fiber group exceeds 100 kΩ or when the fiber group electrical resistance value of the second fiber group is less than 0.001Ω, the addition amount of the conductivity adjusting material of the present invention to the polymer material is There is a possibility that the electrical resistance value of the polymer material hardly changes even if it is significantly changed, and in order to finely adjust the conductivity of the polymer material step by step, a large amount of the conductivity adjusting material of the present invention is required. There is a case.

  In addition, the fiber group electrical resistance values of the first fiber group and the second fiber group are usually set as described above by appropriately adjusting the firing temperature when manufacturing the short carbon fibers constituting each fiber group. Can be set to a range.

In the conductivity adjusting material of the present invention, the weight ratio of the first fiber group is preferably set larger than the weight ratio of the second fiber group. For example, when the weight ratio of the second fiber group is larger than the weight ratio of the first fiber group in the conductive adjustment material according to the above-described aspect 1, the electrical resistance of the polymer material including the conductive adjustment material becomes small. For example, the electrical resistance value (volume specific resistance value: the same shall apply hereinafter) of the polymer material is about 10 ⁵ to 10 ¹³ Ωcm, particularly about 10 ¹⁰ to 10 ¹³ Ωcm. It becomes difficult to set. On the other hand, when the weight ratio of the second fiber group is larger than the weight ratio of the first fiber group in the conductivity adjusting material according to the above-described aspect 2, the electrical resistance value of the polymer material including the conductivity adjusting material is large. become too trend (i.e., the tendency of the conductivity too low) may, for example, an electric resistance value ¹⁰⁵ to ¹³ [Omega] cm approximately polymeric materials, it is difficult to set the particular 10 ⁵ to 10 about ¹⁰ [Omega] cm .

Incidentally, when adjusting the electric resistance of the polymeric material using the conductive adjusting material present invention to a target range of about 10 ⁵ to 10 ¹³ [Omega] cm, the ratio of the first fiber group has 50 wt% or more 99.9 It is preferable to set the ratio of the second fiber group to less than wt% and 50 wt% or less and 0.1 wt% or more.

  The conductivity adjusting material for a polymer material of the present invention is used for adjusting the conductivity of various polymer materials, that is, for producing a conductive polymer material as described later. In this case, the conductive preparation material of the present invention is usually supplied to the polymer material so that the first fiber group and the second fiber group are prepared separately and the ratio of both fiber groups is as described above. Is done. At this time, the first fiber group and the second fiber group may be separately supplied and mixed to the polymer material, or may be supplied to the polymer material after being mixed in advance.

Conductive polymer material The conductive polymer material of the present invention includes a polymer material and the above-described conductivity adjusting material according to the present invention, for example, the above-described conductivity adjusting material according to Aspect 1 or Aspect 2. It has electrical conductivity.

The polymer material constituting the conductive polymer material is not particularly limited, and includes various known thermoplastic resins, thermosetting resins, rubbers, and the like.
Here, as the thermoplastic resin, for example, general-purpose plastics such as polyethylene resin, polypropylene resin, polystyrene resin and polyacryl styrene resin, acrylic-butadiene-styrene resin (ABS), polyphenyl ether resin, polyacetal resin, polycarbonate resin, Engineering plastics such as polybutylene terephthalate resin, polyethylene terephthalate resin, nylon 6 and nylon 6,6, polyether ether ketone resin, polyamide resin, polyimide resin, polysulfone resin, 4-fluoroethylene-ethylene copolymer resin, polyfluoride Vinylidene fluoride resin, 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer resin, polyetherimide resin, polyether sulfone resin, It can be mentioned Li polyphenylene sulfide resin, a modified polyphenylene oxide resin, super engineering plastics such as polyphenylene ether resin and a liquid crystal polymer and the like. Moreover, as a thermosetting resin, a phenol resin, an epoxy resin, a polyimide resin, an unsaturated polyester resin etc. can be mentioned, for example. Further, as rubber, natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, ethylene-propylene rubber, acrylic rubber, epichlorohydrin rubber, polysulfide rubber, urethane rubber, polyolefin elastomer and silicone rubber And so on.

  In the case of producing such a conductive polymer, usually, the above-described conductivity adjusting material according to the present invention is supplied and mixed with the polymer material using various known feeders. At this time, the conductivity adjusting material may be supplied to the polymer material separately from the first fiber group and the second fiber group, or may be supplied to the polymer material after being mixed in advance. Good.

The amount of the conductivity adjusting material added to the polymer material can be appropriately set according to the conductivity (electric resistance value) of the target polymer material. At this time, since the conductivity adjusting material includes the first fiber group and the second fiber group as described above, the conductivity of the polymer material is gradually increased stepwise as the addition amount is gradually increased. can go. In other words, it is difficult for the conductivity adjusting material of the present invention to significantly change the conductivity of the polymer material as long as the amount added to the polymer material is slightly changed. For this reason, when this conductivity adjusting material is used, it is difficult to achieve with a conventional conductivity adjusting material such as carbon black, and a weak conductivity of about 10 ⁵ to 10 ¹³ Ωcm is a polymer material. Can be easily applied.

Moreover, the electroconductivity adjusting material of this invention can also change the electroconductivity which can be provided with respect to a polymeric material by changing the ratio of a 1st fiber group and a 2nd fiber group. For example, in the case where the conductivity adjusting material is the above-described aspect 1, when the ratio of the second fiber group is increased, even if the amount of the conductivity adjusting material added to the polymer material is substantially the same, The conductivity can be set large (that is, the electric resistance value can be set small). On the other hand, in the case where the conductivity adjusting material is in the above-described aspect 2, when the ratio of the second fiber group is increased, even if the amount of the conductivity adjusting material added to the polymer material is substantially the same, The conductivity can be set small (that is, the electric resistance value can be set large). That is, the conductivity adjusting material of the present invention changes the ratio of the first fiber group and the second fiber group, thereby setting the amount of addition to the polymer material to the minimum necessary amount while conducting the conductivity of the polymer material. The properties can be arbitrarily adjusted in the range of 10 ⁵ to 10 ¹³ Ωcm.

In such a conductive polymer, when the conductivity (electric resistance value) is set to about 10 ⁵ to 10 ¹³ Ωcm, the content of the above-described conductivity adjusting material in the polymer material is generally 5 to 40. It is preferable to set so that it may become weight%, and it is more preferable to set so that it may become 6 to 15 weight%.

  The conductive polymer material of the present invention includes the above-described conductivity adjusting material and is imparted with conductivity, so that it is necessary to prevent antistatic and dust adhesion, such as jigs for semiconductor manufacturing, ICs, etc. It can be used for various applications such as trays and carriers.

Examples 1-3
The fiber group electrical resistance value is 6.36 Ωcm made of isotropic pitch-based carbon short fibers (trade name “Xylus GCR-1” of Osaka Gas Co., Ltd.) having an average fiber diameter of 12 μm and an average aspect ratio of 250. Fiber group electrical resistance value comprising the first fiber group and an anisotropic pitch-based carbon short fiber (trade name “UFM-1” of Osaka Gas Co., Ltd.) having an average fiber diameter of 2 μm and an average aspect ratio of 250 Was prepared with a second fiber group of 3,300 Ωcm.

Supply the first fiber group and the second fiber group to the polymer material polyphenylene oxide resin (trade name “Noryl PPO534” of Nippon General Electric Co., Ltd.) using the separate feeders in the ratios shown in Table 1. And the pellet which consists of a polymeric material containing a 1st fiber group and a 2nd fiber group was prepared. The pellets were molded using a PROMAT injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. under conditions of a resin temperature of 300 ° C., an injection pressure of 2,000 kg / cm ² and a mold temperature of 160 ° C., and the diameter was 50 mm and the thickness was 3 mm. Got the disc. An electrode was formed using a silver paste on the surface of the obtained disk, and the electric resistance between the electrodes was measured to determine the surface resistance (Ω / □) of the disk. The results are shown in Table 1.

Examples 4-6
A first fiber having an average fiber diameter of 12 μm and an isotropic pitch short carbon fiber having a mean aspect ratio of 250 (trade name “Xylus GC03J401” from Osaka Gas Co., Ltd.) having a fiber group electrical resistance of 0.14 Ωcm. A fiber group comprising a polyacrylonitrile-based short carbon fiber (trade name “Pyrofil”, manufactured by Mitsubishi Rayon Co., Ltd.) having an average fiber diameter of 7 μm and an average aspect ratio of 857, and having an electrical resistance value of 0.29 Ωcm. Two fiber groups were prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. The results are shown in Table 2.

Examples 7 and 8
A fiber having an average fiber diameter of 2 μm and an average aspect ratio of 250, an anisotropic pitch-based short carbon fiber (trade name “UFM-2” from Osaka Gas Co., Ltd.) and having a fiber group electrical resistance of 0.19 Ωcm Discs were obtained in the same manner as in Examples 4 to 6 except that the group was used as the second fiber group. Then, the surface resistance (Ω / □) of the obtained disc was measured in the same manner. The results are shown in Table 2.

Examples 9-11
A first fiber group having a fiber group electrical resistance value of 0.29 Ωcm, comprising a polyacrylonitrile-based carbon short fiber (trade name “Pyrofil”, manufactured by Mitsubishi Rayon Co., Ltd.) having an average fiber diameter of 7 μm and an average aspect ratio of 857; The fiber group electrical resistance value is 3,300 Ωcm, which is made of an anisotropic pitch carbon short fiber (trade name “UFM-1” of Osaka Gas Co., Ltd.) having an average fiber diameter of 2 μm and an average aspect ratio of 250. A second fiber group was prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. The results are shown in Table 3.

Examples 12-14
A first fiber group having a fiber group electrical resistance value of 0.29 Ωcm, comprising a polyacrylonitrile-based carbon short fiber (trade name “Pyrofil”, manufactured by Mitsubishi Rayon Co., Ltd.) having an average fiber diameter of 7 μm and an average aspect ratio of 857; The fiber group electrical resistance value is 0.19 Ωcm, which is made of an anisotropic pitch-based carbon short fiber (trade name “UFM-2” of Osaka Gas Co., Ltd.) having an average fiber diameter of 2 μm and an average aspect ratio of 250. A second fiber group was prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. The results are shown in Table 4.

Example 15
A first fiber group having an average fiber diameter of 13 μm and a pitch group carbon short fiber having an average aspect ratio of 54 (trade name “DonnaCarbo S244” manufactured by Donak Co., Ltd.), and having a fiber group electrical resistance of 1.2 Ωcm; A second fiber group having a fiber group electrical resistance of 0.29 Ωcm, comprising a polyacrylonitrile-based carbon short fiber (trade name “Pyrofil”, manufactured by Mitsubishi Rayon Co., Ltd.) having an average fiber diameter of 7 μm and an average aspect ratio of 857; Prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. However, acrylonitrile-butadiene-styrene copolymer resin (trade name “Toyolac 100” manufactured by Toray Industries, Inc.) is used as the polymer material, and the resin temperature, injection pressure, and mold temperature are 240 ° C. and 1,200 kg / cm ² , respectively. And 60 ° C. The results are shown in Table 5.

Examples 16-18
A first fiber group having an average fiber diameter of 12 μm and an average aspect ratio of 250 pitch-based carbon short fibers (trade name “Xylus GCA03J431” from Osaka Gas Co., Ltd.) and having a fiber group electrical resistance of 7,790 Ωcm; And a second fiber group having a fiber group electrical resistance of 0.29 Ωcm, comprising a polyacrylonitrile-based short carbon fiber (trade name “Pyrofil” of Mitsubishi Rayon Co., Ltd.) having an average fiber diameter of 7 μm and an average aspect ratio of 857. And prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. The results are shown in Table 5.

Examples 19-21
A first fiber having an electrical resistance value of 6.36 Ωcm, comprising an isotropic pitch-based carbon short fiber (trade name “Xylus GCR1” from Osaka Gas Co., Ltd.) having an average fiber diameter of 12 μm and an average aspect ratio of 250. The electrical resistance value of the fiber group is 0 consisting of the fiber group and an anisotropic pitch carbon short fiber (trade name “UFM-4” of Osaka Gas Co., Ltd.) having an average fiber diameter of 2 μm and an average aspect ratio of 250. A second fiber group of .05 Ωcm was prepared.
A disk was obtained in the same manner as in Examples 1 to 3 using the first fiber group and the second fiber group, and the surface resistance (Ω / □) was measured in the same manner. The results are shown in Table 5.

Comparative Example 1
Using only a fiber group having an average fiber diameter of 13 μm and a pitch group carbon short fiber having an average aspect ratio of 54 (trade name “Donna Carbo S244” manufactured by Donak Co., Ltd.) and having a fiber group electrical resistance of 1.2 Ωcm. Pellets were prepared in the same manner as in Examples 1 to 3, and disks were obtained from the pellets in the same manner as in Examples 1 to 3. However, the polymer material was changed to a polyether sulfone resin (trade name “Sumika Excel 4100” from Sumitomo Chemical Co., Ltd.), and the resin temperature, injection pressure and mold temperature were 330 ° C. and 1,500 kg / cm, respectively. Changed to ² and 140 ° C. Table 6 shows the results of measuring the surface resistance (Ω / □) of the disk in the same manner as in Examples 1 to 3.

Comparative Example 2
Only fiber groups having an average fiber diameter of 12 μm and a pitch group carbon short fiber (trade name “Xylus GCA03J431” from Osaka Gas Co., Ltd.) having an average aspect ratio of 250 and a fiber group electrical resistance of 7,790 Ωcm are used. Then, pellets were prepared in the same manner as in Examples 1 to 3, and disks were obtained from the pellets in the same manner as in Examples 1 to 3. Table 6 shows the results of measuring the surface resistance (Ω / □) of the disk in the same manner as in Examples 1 to 3.

Comparative Example 3
A fiber having an average fiber diameter of 2 μm and an average aspect ratio of 250, an anisotropic pitch-based short carbon fiber (trade name “UFM-2” from Osaka Gas Co., Ltd.) and having a fiber group electrical resistance of 0.19 Ωcm Using only the group, pellets were prepared in the same manner as in Examples 1 to 3, and disks were obtained from the pellets in the same manner as in Examples 1 to 3. Table 6 shows the results of measuring the surface resistance (Ω / □) of the disk in the same manner as in Examples 1 to 3.

Comparative Example 4
Ketjen Black (trade name “Ketjen Black EC” from Ketjen Black International Co., Ltd.) is a conductive material for high-density polyethylene resin (trade name “Hi-Zex 1300J” from Mitsui Petrochemical Co., Ltd.). ) Was supplied at a ratio shown in Table 3 to prepare pellets, and discs were formed using the pellets in the same manner as in Examples 1 to 3. At this time, the resin temperature, injection pressure, and mold temperature at the time of molding were set to 210 ° C., 1,000 kg / cm ² and 40 ° C., respectively. Table 7 shows the results of measuring the volume resistivity (Ωcm) of the disk.

Comparative Example 5
A disc was obtained in the same manner as in Comparative Example 4 except that acetylene black (trade name “DENKA BLACK” manufactured by Denki Kagaku Kogyo Co., Ltd.) was used as the conductive material. Table 7 shows the results of measuring the volume resistivity (Ωcm) of this disk.

Claims (1)

A polymer material;
A conductivity adjusting material added to the polymer material,
The conductivity adjusting material includes a first fiber group made of first carbon short fibers and a second fiber group made of second carbon short fibers having an average fiber diameter smaller than that of the first carbon short fibers, and the first fibers The group has a larger fiber group electrical resistance value than the second fiber group,
Conductive polymer material.