JP4464254B2 - Conductive gel composition - Google Patents

Description

  The present invention relates to a conductive gel composition having conductivity and flexibility.

Conventionally, in electronic devices such as mobile phones, PDAs, personal computers, and liquid crystal televisions, for example, due to the influence of radiated electromagnetic waves from other nearby devices, lightning, solar activity, etc. It has been pointed out that there is a risk of malfunctions such as malfunction, stoppage and loss of records. In addition, electronic devices may adversely affect the operation of other devices and the health of nearby human beings due to the electromagnetic waves emitted by the electronic devices.
Specific examples include noise in the sound of a radio near a personal computer, leakage of surge current due to power switching, influence on living bodies due to leaked electromagnetic waves, and the like.

  In recent years, more and more electronic devices have entered daily life, and the use of radio waves has been expanding. Along with this, concerns about the influence of the electromagnetic environment on the human body are spreading. Further, in semiconductor chips and the like, miniaturization, miniaturization, and reduction in power are progressing, and the electromagnetic resistance of the chip itself is lowered. From such a background, an electromagnetic device (EMI: Electro Magnetic Interference) that does not cause an interference source (EMI: Electro Magnetic Susceptibility) that does not hinder its own operation, that is, an electromagnetic environment compatibility (EMC: Electro) Development of electronic equipment with Magnetic Cmpatibility) is required.

On the other hand, electronic devices may be damaged or malfunction due to external impacts. Therefore, in an electronic device, the impact resistance is improved by disposing a highly flexible material in a place where it is easily damaged.
In recent years, even in such flexible materials, a material having both conductivity and conductivity (conductive gel material) is required for the above-described EMC countermeasures.

As a specific use of the conductive gel material, there is a shielding case used for, for example, a casing of a mobile phone (see Patent Document 1).
In the shielding case, when the case is sealed, a shielding packing for shielding the case is formed at a contact portion between the case and the case. As a material for such a shielding packing, a material that can shield the contact portion with good adhesion and can take EMC countermeasures has been desired. Therefore, a material having both flexibility and conductivity has been demanded.
Conventionally, as a material for such shielding packing, for example, silicone rubber containing conductive particles such as metal has been used.

In addition, for example, a material having both flexibility and conductivity has been demanded for liquid crystal display panels such as liquid crystal televisions, liquid crystal displays, and mobile phones.
That is, in a liquid crystal display panel, a gasket is disposed between the liquid crystal display panel and a casing (substrate) that comes into contact with the liquid crystal display panel in order to protect the liquid crystal display panel from impact and to take measures against EMC. As the material of this gasket, a material having both flexibility and conductivity as described above is desired.

  However, conventional shielding packing and gasket materials have a problem that they are hardly able to exhibit conductivity in a low load state. Therefore, in order to exhibit conductivity, it is necessary to apply a large load to the shield packing, the gasket, and the like. However, especially in the case of gaskets for liquid crystal display panels, if a large load is applied, the liquid crystal display panel is destroyed, and the impact absorption performance of the gasket itself is reduced. There was a risk of being. For this reason, there is a problem that a large load cannot be applied, conductivity is hardly exhibited, and sufficient EMC measures cannot be taken.

JP-T-2001-504280

  This invention is made | formed in view of this conventional problem, Comprising: It aims at providing the electroconductive gel composition which is excellent in a softness | flexibility and can exhibit electroconductivity by a low load.

The present invention is a conductive gel composition containing a base resin composed of a styrene elastomer, a softener, and a conductive filler,
The conductive gel composition contains 400 to 1500 parts by weight of the softening agent and 500 to 3000 parts by weight (excluding 500 parts by weight) of the conductive filler with respect to 100 parts by weight of the base resin. And a durometer hardness of A40 or less, in a conductive gel composition (Claim 1).

The conductive gel composition of the present invention has the specific composition described above, and has a specific hardness of durometer hardness of A40 or less.
Therefore, the conductive gel composition is excellent in flexibility, and can exhibit conductivity in a low load state of, for example, 5 × 10 ³ Pa or less or in a state where no load is applied. Therefore, the conductive gel composition can be suitably used for applications that require flexibility and conductivity, such as gaskets and shield packings for electronic devices.

  Thus, according to this invention, the electroconductive gel composition which is excellent in a softness | flexibility and can exhibit electroconductivity with a low load can be provided.

Next, an embodiment of the present invention will be described.
The viscoelastic elastomer of the present invention comprises 400 parts by weight to 1500 parts by weight of the softening agent and 500 to 3000 parts by weight of the conductive filler (excluding 500 parts by weight) with respect to 100 parts by weight of the base resin. contains.
When content of the said softening agent is less than 200 weight part, there exists a possibility that the softness | flexibility of the said electroconductive gel composition may fall. On the other hand, when it exceeds 1500 parts by weight, physical properties such as tensile strength and elongation rate may be lowered, and oil bleed may occur. Preferably, the content of the softening agent is 300 to 900 parts by weight, and more preferably 400 to 600 parts by weight.
Moreover, when content of the said electroconductive filler is less than 150 weight part, there exists a possibility that electroconductivity cannot fully be exhibited. On the other hand, when it exceeds 3000 parts by weight, the hardness becomes too high and the flexibility may be lowered. Preferably, the content of the conductive filler is 300 to 2000 parts by weight, more preferably 500 to 1500 parts by weight.
The conductive filler is contained in a state dispersed in the conductive gel composition.

Next, the base resin is made of a styrene elastomer.
As the base resin, for example, a styrene elastomer having a number average molecular weight of 200,000 or more is preferably used.
When the number average molecular weight of the styrene elastomer is less than 200,000, the strength of the conductive gel composition may be reduced. In this case, there is a risk that distortion is likely to occur due to heat. From the viewpoint of improving kneading processability and molding fluidity, the upper limit of the number average molecular weight of the styrene elastomer is preferably 300,000 or less.

  Examples of the styrenic elastomer of the base resin include styrene ethylene propylene styrene block copolymer (SEPS), styrene ethylene butylene styrene block copolymer (SEBS), styrene ethylene ethylene propylene styrene block copolymer (SEEPS), and One or more selected from styrene isobutylene styrene copolymer (SIBS) and the like can be used.

In addition, as the softening agent, for example, one or more selected from paraffinic process oil, naphthenic process oil, aroma based process oil, polyalphaolefin (PAO), liquid polybutene, liquid polyisobutylene, and the like can be used. .
Preferably, the softening agent is a paraffinic process oil having a kinematic viscosity of 100 mm ² / s or higher at a temperature of 40 ° C.
In this case, the compatibility between the base resin and the softening agent is increased, and generation of oil bleed can be suppressed. As a result, it is possible to suppress the oil generated by the oil bleed from being transferred from the conductive gel composition to the other member and contaminating the other member.

When the kinematic viscosity of the softening agent is less than 100 mm / s ² , the softening agent is likely to volatilize, so that the weight of the conductive gel composition may decrease or the odor may become strong at high temperatures. In this case, the compression set may be increased.
The kinematic viscosity of the softener can be measured by, for example, “crude oil and petroleum products—kinematic viscosity test method and viscosity index calculation method” defined in JIS K 2283.

  Examples of the conductive filler include carbons such as carbon black, carbon nanotube, carbon fiber, and graphite, and conductive metals such as gold, silver, copper, nickel, and stainless steel. Further, there are conductive powders and the like in which a conductive coating layer made of the above carbons or conductive metal is formed on the surface by plating or coating. These can be used alone or in combination of two or more. Moreover, what coated the conductive metal can also be used as carbons. In addition to the metals listed above, examples of the conductive metal include alloys of the above-described conductive metal and other metals.

  Preferably, the conductive filler is a conductive powder in which a metal film made of nickel or the like is coated on a particle made of carbon such as graphite by a CVD method (pure fluidized bed chemical vapor deposition method) or the like. It is good to use. When coating is performed by the CVD method, the thickness of the metal film can be made very small. Therefore, in this case, the amount of conductive metal such as nickel having a large specific gravity can be reduced, and the weight can be reduced without changing the volume. As a result, the conductive gel composition can be reduced in weight, and the amount of conductive metal such as nickel can be reduced, so that the cost can be reduced.

In addition, the conductive filler preferably has an aspect ratio of 1 to 5.
When the aspect ratio of the conductive filler exceeds 5, the conductive gel composition may become hard or the moldability of the conductive gel composition may be deteriorated.
The aspect ratio of the conductive filler refers to the ratio (L / B) between the maximum value (L) of the length in the longitudinal direction of the conductive filler and the minimum value (B) of the length in the substantially vertical direction. . More preferably, the conductive filler has an aspect ratio of 3 or less, and more preferably 2 or less.

The conductive gel composition has a durometer hardness of A40 or less.
When durometer hardness exceeds A40, there exists a possibility that the softness | flexibility of the said electroconductive gel composition may fall. Therefore, in this case, when the conductive gel composition is bonded to, for example, another member to establish electrical continuity with the other member, the contact portion becomes insufficiently connected, and the conductive gel composition is conductive unless a large load is applied. There is a risk that it will not be possible to fully exhibit the properties.
The durometer hardness can be measured, for example, by a durometer hardness test (type A) defined in JIS K 6253 (1997).

  The conductive gel composition can be prepared by heating, melting and kneading the base resin, the softener, and the conductive filler as essential components using a kneader or an extruder. The conductive gel composition includes a fluidity improving resin, a filler, and a color pigment as subcomponents other than the essential components as long as the flexibility and conductivity of the conductive gel composition are not impaired. Functional fillers can be added. After kneading, it can be formed into a desired shape such as a sheet by, for example, injection molding, compression molding, T-die extrusion molding or the like to obtain a molded body.

The fluidity improving resin can be contained in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the base resin.
In this case, the fluidity of the conductive gel composition can be increased, and the moldability of the conductive gel composition can be improved.
When the content of the fluidity improving resin is less than 1 part by weight, the effect of improving the fluidity of the conductive gel composition may not be sufficiently obtained. On the other hand, when it exceeds 50 weight part, the said electroconductive gel composition becomes hard and there exists a possibility that a softness | flexibility may fall.
Moreover, as said fluid improvement resin, 1 or more types chosen from a polypropylene, polystyrene, polyethylene, modified polyolefin, polypentene, a fluorine-type polymer, etc. can be used, for example. Polypropylene is preferable.

Further, the filler can be contained in an amount of 100 parts by weight or less with respect to 100 parts by weight of the base resin.
In this case, the manufacturing cost of the conductive gel composition can be reduced while maintaining the above-described flexibility and conductivity of the conductive gel composition.
When the filler content exceeds 100 parts by weight, flexibility and conductivity may not be sufficiently exhibited.
Examples of such fillers include calcium carbonate, talc, clay, silica, aluminum hydroxide, magnesium hydroxide, and barium sulfate.

The color pigment can be contained in an amount of 0.1 to 50 parts by weight with respect to 100 parts by weight of the base resin.
In this case, a desired color can be imparted to the conductive gel composition.
When the content of the coloring pigment is less than 0.1 parts by weight, there is a possibility that desired coloring cannot be sufficiently imparted. On the other hand, when the amount exceeds 50 parts by weight, the coloring pigment aggregates to cause poor dispersion, and when the conductive gel composition is used by being attached to, for example, another member, the color is transferred to the other member. There is a fear.

Examples of the color pigment include natural inorganic pigments, synthetic inorganic pigments, natural organic pigments, and synthetic organic pigments.
Examples of natural inorganic pigments include earth-based pigments such as yellow ocher, tail belt, low senna, low amber, kassel earth, chalk, plaster, etc., burned soil such as burnt senna, burnt amber, lapis lazuli, azurite, malachite, opiment, dredged sand, etc. Mineral pigments, powders, and peppers.

  Examples of the synthetic inorganic pigment include cobalt blue, cerulean blue, cobalt violet, cobalt green, zinc white, titanium white, oxide pigments such as light red, chrome oxide green, and mars black, water such as viridan, yellow ocher, and alumina white. Oxide pigments, sulfide pigments such as cadmium yellow, cadmium red, vermilion, lithopone, silicate pigments such as ultramarine, talc, white carbon, clay, phosphate pigments such as mineral violet and rose cobalt violet, silver white, Carbonate pigments such as calcium carbonate, metal powder pigments such as gold powder, bronze powder and aluminum powder, carbon pigments such as ivory black, peach black, lamp black and carbon black, plus Lou, Oreorin, there is a mica titanium or the like.

  Examples of natural organic pigments include plant pigments such as madder lake, pink madder, gunborg, and dragon blood, animal pigments such as cochineal, kermes lake, chilian purple, and sepia, and mineral pigments such as bitumen.

  Synthetic organic pigments include, for example, dyed lake pigments such as alizarin lake, rhodamine lake, quinoline yellow lake, soluble azo pigments such as lake red C, brilliant carmine 6B, permanent red 2B, first yellow, disazo yellow, naphthol red, etc. Insoluble azo pigments, condensed azo pigments such as chromophthal yellow and chromophthal red, azo complex pigments such as nickel azo yellow and benzimidazolone yellow, phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green, thioindigo, perylene red, dioxazine violet, Examples thereof include condensed polycyclic pigments such as quinacridone red-anthraquinone, perinone, isoindolinone, azomethine, and fluorescent pigments.

Moreover, the said functional filler can be contained 100-10000 weight part with respect to 100 weight part of said base resin.
When content of the said functional filler is less than 100 weight part, there exists a possibility that the desired effect which various functional fillers have cannot fully be provided to the said electroconductive gel composition. On the other hand, when it exceeds 10,000 parts by weight, the flexibility and conductivity of the conductive gel composition may be impaired.

  Examples of the functional filler include plasticizers, lubricants, flame retardants, vulcanizers, vulcanization aids, stabilizers, crack inhibitors, antioxidants, ultraviolet absorbers, anti-aging agents, ozone deterioration inhibitors, One or more selected from mold agents, fungicides, dispersants, antistatic agents, fillers, flow modifiers, heat transfer fillers, and the like can be used.

The conductive gel composition, Ru can be used for the electrode material for the microphone holder.
In this case, the electrical continuity can be reliably ensured by taking advantage of the property that the conductive gel composition can exhibit conductivity at a low load.
In general, the microphone holder is made of a rubber elastic body having excellent flexibility in order to protect an electronic component such as a microphone housed therein. For this reason, if a material with very low flexibility such as metal is embedded in the microphone holder to form electrical continuity between the inside and outside of the microphone holder, the flexibility between the conductive portion made of metal and the microphone holder made of rubber elastic body Due to the difference in characteristics, external vibration and noise may be transmitted as noise, and the speech recognition rate may be reduced.
When the conductive gel composition of the present invention is used as an electrode material for a microphone holder, the conductive gel composition can exhibit high vibration insulation efficiency by taking advantage of the excellent flexibility of the conductive gel composition. The above problem can be avoided.

Also, the conductive gel composition, Ru can be used for shielding gasket of the electronic device.
The shield packing is a filling material that is packed in a gap between portions where the cases come into contact with each other in a case that houses an electronic device.
When the conductive gel composition is used for shield packing of an electronic device, the conductive gel composition can exhibit conductivity even when a large load is not applied, taking advantage of the property that the conductive gel composition can exhibit conductivity at a low load. Therefore, EMC countermeasures can be taken more reliably. Moreover, the space | interval of the contact part of cases can be filled reliably using the outstanding softness | flexibility of the said electroconductive gel composition.
As a specific example of the shield packing, for example, there is a shield packing arranged between cases of an electronic device such as a mobile phone.

Also, the conductive gel composition, Ru can be used for the gasket of the electronic device.
A gasket is a supplementary material that is disposed in a gap between constituent members constituting an electronic device to fill the gap and stably hold the constituent members.
When the conductive gel composition is used for a gasket of an electronic device, taking advantage of the property that the conductive gel composition can exhibit conductivity at a low load, the conductivity can be exhibited without applying a large load. Electromagnetic wave shielding can be achieved more reliably. In addition, by taking advantage of the excellent flexibility of the conductive gel composition, it is possible to securely fill the gaps and stably hold the components of the electronic device, and also to play a role of an impact absorbing material that absorbs external impact Can be fulfilled.
Specific examples of the gasket to which the conductive gel composition can be applied include, for example, a liquid crystal display panel such as a liquid crystal television, a liquid crystal display, and a mobile phone, and a casing or a substrate that comes into contact with the liquid crystal display panel. There are gaskets and the like disposed between the members. It can also be used for gaskets for personal computers, PDAs, batteries, and the like.

Also, the conductive gel composition, Ru can be used for grounding member for taking ground from the electronic component.
In this case, taking advantage of the property that the conductive gel composition can exhibit conductivity at a low load, the ground can be more reliably taken. Moreover, since the said electroconductive gel composition has the outstanding softness | flexibility, it can protect an electronic component etc. from an external impact, taking an earth as mentioned above.

  The conductive gel composition can also be used as a damper material (vibration absorber) for the HDD unit.

Moreover, it is preferable that the said electroconductive gel composition exhibits electroconductivity and exhibits electrical resistance in the state which applied the load of 5 * 10 < ³ > Pa or less.
If the load when exhibiting electrical conductivity and exhibiting electrical resistance exceeds 5 × 10 ³ Pa, sufficient EMC measures will be taken when the conductive gel composition is used in shield packing or gaskets of electronic equipment. May not be possible. Further, when used for a grounding member of an electronic device, there is a possibility that it cannot be sufficiently grounded. More preferably, the load when the conductive gel composition exhibits electrical resistance is preferably 1 × 10 ³ Pa or less, and more preferably 1 × 10 ² Pa or less. Most preferred is 0 Pa.

Example 1
Next, an embodiment of the present invention will be described with reference to FIGS.
In this example, a conductive gel composition is prepared and its flexibility and conductivity are evaluated.
The conductive gel composition of this example contains a base resin composed of a styrene elastomer, a softening agent, and a conductive filler. The conductive gel composition contains 600 parts by weight of a softening agent and 1100 parts by weight of a conductive filler with respect to 100 parts by weight of the base resin, and has a durometer hardness of A40 or less.

Hereinafter, the manufacturing method of the electroconductive gel composition of this example is demonstrated.
First, SEPS as a base resin (having a number average molecular weight of about 200,000 and a styrene content of about 30 wt%), paraffinic process oil as a softening agent (having a kinematic viscosity of 400 mm ² / s at a temperature of 40 ° C. And Ni-coated graphite (with an average particle size of 74 μm and a nickel ratio of 40 wt%) as a conductive filler.

Next, 100 parts by weight of the base resin, 600 parts by weight of the softening agent, and 1100 parts by weight of the conductive filler were heated and melted and kneaded using a kneader or an extruder to obtain a conductive gel composition.
In this example, the conductive gel composition obtained after kneading was molded into a sheet by injection molding to obtain a molded body. This is designated as Sample E.
About the obtained sample E, durometer hardness was measured based on the prescription | regulation of JISK6253 (1997). As a result, the durometer hardness of Sample E was A8.
Table 1 shows the composition and durometer hardness of Sample E.

In this example, a conductive elastomer based on silicone rubber was prepared for comparison with Sample E.
Specifically, 100 parts by weight of silicone rubber, 100 parts by weight of silver-coated ceramic, and 60 parts by weight of a flame retardant were kneaded using a kneader or an extruder to obtain a conductive elastomer. Thereafter, like the sample E, it was molded into a sheet by injection molding. This is designated as Sample C.
About the obtained sample C, when the durometer hardness was measured based on prescription | regulation of JISK6253 (1997), the durometer hardness of the sample C was A60.
Table 1 shows the composition and durometer hardness of Sample C.

Next, the vibration characteristics of each sample (sample E and sample C) were evaluated as follows (vibration test).
"Vibration test"
First, four test pieces having a thickness of 3 mm, a length of 5 mm, and a width of 5 mm were cut out from the sample E. Next, a vibration device 2 was prepared as shown in FIG. The vibration device 2 is a device that generates vibration of a predetermined frequency to vibrate the shaking table 25. A 400 g load plate 3 was prepared.
Four test pieces (sample E) 1 are respectively arranged on the shaking table 25, and the load plate 3 is arranged and fixed from above the test piece 1 so as to sandwich the test piece between the shaking table 25 and the load plate 3. . At this time, each test piece 1 was arranged at each of the four corners of the shaking table 25 so as to support the load plate 3 at four points.
Next, the shaking table 25 was vibrated by operating the vibration device 2 at an acceleration of 0.4 G. At this time, the frequency of vibration was changed from 5 Hz to 1000 Hz under a sweep condition of 2.5 min / sweep. And the vibration of the load board 3 arrange | positioned at the upper part of each test piece 1 was detected with the acceleration pick-up, and the resonance curve was produced. For sample C, a vibration test was performed in the same manner as for sample E, and a resonance curve was prepared. The result is shown in FIG. This vibration test was conducted under the condition of a temperature of 23 ° C. In FIG. 2, the horizontal axis represents frequency (Hz) and the vertical axis represents resonance magnification (dB).

The resonance frequency (Hz), resonance magnification (dB), and loss factor of each sample obtained in the vibration test are shown in Table 2 described later.
Here, the resonance frequency indicates a frequency when the largest resonance occurs. The resonance magnification is the ratio of the acceleration obtained from the load plate to the acceleration generated by the vibration exciter when the largest resonance is obtained, and is converted in decibels.

Further, the loss coefficient tan δ can be obtained from the resonance curve as follows. For example, a method for calculating the loss coefficient of the sample E will be described.
First, FIG. 3 shows an enlarged view of a portion where the resonance magnification becomes maximum in the resonance curve of sample E (solid line in FIG. 2). In FIG. 3, for the convenience of explanation of the resonance magnification, the maximum portion is shown as being almost bilaterally symmetrical, but the actual state is as shown in FIG. 2.
As shown in FIG. 3, the loss factor tan δ shows a frequency f ₀ when the resonance magnification shows a maximum value (a peak value of the resonance magnification) and a resonance magnification that is 3 dB lower than the peak value of the resonance magnification in the resonance curve. Based on the frequency f ₁ and f _{2 at the time} (f ₁ <f ₀ <f ₂ ), it was calculated from the following formula (1) (half-value width method).
tan δ = Δf / f ₀ = (f ₂ −f ₁ ) / f ₀ ... (1)

Further, the conductivity of each sample (sample E and sample C) was evaluated as follows (conductivity test).
"Conductivity test"
First, a test piece 1 having a thickness of 3 mm, a length of 10 mm, and a width of 30 mm was cut out from the sample E. Next, as shown in FIG. 4, the two plated copper plates 41 and 42 were placed at a distance of 10 mm, and the test piece 1 was placed so as to bridge the plated copper plates 41 and 42. Next, a voltage was applied between the two plated copper plates 41 and 42, and a constant current of 0.1 A was applied. The electrical resistance at this time was measured by the four probe method. The results are shown in Table 2 below.
Furthermore, a 100 g weight load was applied from the top of the test piece 1, and the same electrical conductivity test was performed to measure the electrical resistance at that time. The results are shown in Table 2 below.
For sample C, as in sample E, the electrical resistance was measured by a four-terminal method in a state where a load was applied and a state where no load was applied. The results are shown in Table 2.

As can be seen from FIG. 2 and Table 2, it can be seen that Sample E exhibits a very low resonance frequency of 1/4 or less that of Sample C. Therefore, the sample E can exhibit excellent flexibility.
Sample E shows a relatively high resonance magnification in a region of a frequency less than about 70 Hz, but the resonance magnification is a negative value at a frequency of about 70 Hz or more. It can be seen that a high anti-vibration performance can be exhibited with respect to the frequency.

  Further, as is known from Table 2, it can be seen that Sample E exhibits electrical resistance even when no load is applied and can exhibit electrical conductivity. On the other hand, Sample C could not exhibit conductivity unless a load was applied.

As described above, it can be seen that the sample E is excellent in flexibility and can reliably exhibit conductivity even in a low load state. Therefore, it is suitable as an electrode material for a microphone holder, a shield packing for an electronic device, a gasket, a grounding material, and the like.
Moreover, since the sample E has the anti-vibration performance excellent as mentioned above, it can also be utilized as a damper material (vibration absorber) or the like.

(Example 2)
In this example, the conductive gel composition is used as an electrode material for a microphone holder.
As shown in FIG. 5A, the microphone holder 5 of this example includes a case portion 52 into which an electronic component 51 such as a microphone is inserted, a metal electrode 515 of the electronic component 51 in the case portion 52, and an electron outside the microphone holder. It is comprised from the elastic connector part 525 which electrically connects components. The case part and the elastic connector part are made of a styrenic gel having flexibility in order to protect the electronic component.

  A conductive hole 527 is formed in the elastic connector portion 525, and the conductive gel composition (electrode material) 1 is embedded in the conductive hole 527. The conductive gel composition 1 is connected to the metal electrode 515 of the electronic component 51. In this example, a conductive gel composition 1 having the same composition as sample E of Example 1 was used.

As shown in FIGS. 5A and 5B, the microphone holder 5 is mounted in a housing 59 such as a mobile phone. In the housing 59, the elastic connector portion 525 of the microphone holder is connected to the metal electrode 551 formed on the other electronic component (substrate) 55 by the conductive gel composition 1 embedded in the conduction hole 527. . In this example, the metal electrode 551 is formed concentrically on the electronic component 55 as shown in FIG.
As described above, the electrode material (conductive gel composition) 1 is connected to the metal electrode 515 of the electronic component 51 and the metal electrode 551 on the electronic component (substrate) 55 to achieve electrical conduction therebetween. it can.

In the microphone holder 5 of this example, the conductive gel composition (sample E) produced in Example 1 is used as the electrode material.
Therefore, in the microphone holder 5 of the present example, the conductivity of the elastic connector portion can be ensured with almost no load applied to the electrode material. In addition, the conductive gel composition (sample E) is excellent in flexibility and can exhibit high vibration insulation efficiency. Therefore, compared to the case where a metal material is used as an electrode material, external vibration and noise are generated as noise. It is possible to further suppress the voice recognition rate from being lowered.

(Example 3)
In this example, the conductive gel composition is used for shield packing of an electronic device.
As shown in FIGS. 6 and 7, the shield packing (conductive gel composition) 1 of this example is an example of the shield packing 1 disposed at the contact portion of the housing 6 of the mobile phone.

As shown in FIGS. 6 and 7, the case 6 of the mobile phone of this example includes two cases 61 and 62. An electronic component 65 is built in the housing 6.
In this example, the shield packing 1 made of a conductive gel composition is formed at the contact portion of the housing 61 with the housing 62. Sample E prepared in Example 1 was used as the conductive gel composition.
As shown in FIG. 7, by bonding these two casings 61 and 62 together, a casing 6 for a mobile phone that incorporates an electronic component 65 can be formed.

In this example, the conductive gel composition (sample E) produced in Example 1 is used as the shield packing 1.
Therefore, in the case 6 for the electronic device (mobile phone) of this example, the conductivity can be exhibited without applying a large load to the shield packing 1. Therefore, EMC countermeasures can be more reliably taken. Further, since the shield packing (conductive gel composition) 1 has excellent flexibility, the gap between the contact portions of the casings 61 and 62 can be reliably filled.

Example 4
In this example, the conductive gel composition is used as a grounding member. In this example, a grounding member for grounding from an electronic component (substrate) of a mobile phone will be described.
As shown in FIGS. 8 and 9, the grounding member (conductive gel composition) 1 of this example is disposed inside the casing 62 of the mobile phone described in the third example. In this example, as the grounding member 1, one having the same composition as the sample E produced in Example 1 was used. The grounding member 1 has a sheet shape and can be disposed at a desired position between the housing 62 and the electronic component 65. In this example, they are arranged at the four corners of the electronic component. The grounding member 1 is electrically connected to a ground pattern (not shown) formed on the back side of the electronic component 65.

As described above, in this example, the conductive gel composition (sample E) produced in Example 1 is used as the grounding member 1.
Therefore, the grounding member 1 of this example can exhibit electrical conductivity without applying a load thereto. Therefore, the electronic component 65 can be grounded more reliably. Further, since the grounding member 1 has excellent flexibility, it can absorb an impact from the outside and can protect the electronic component 65 from the impact.

(Example 5)
In this example, the conductive gel composition is used for the gasket. In this example, an example of a gasket disposed between a liquid crystal display panel of a liquid crystal television and a housing (bezel) will be described.
As shown in FIGS. 10 and 11, the gasket (conductive gel composition) 1 of this example is disposed between the liquid crystal display panel 71 and the casing 72 of the liquid crystal television 7. In this example, a gasket 1 having the same composition as the sample E produced in Example 1 was used. The gasket 1 is in the form of a sheet, and is disposed with a desired distance between the liquid crystal display panel 71 and the housing 72.
11 shows a cross-sectional view taken along the line BB of FIG. 10, but the internal structure of the liquid crystal television other than the liquid crystal display panel is omitted for the convenience of drawing.

As described above, in this example, the conductive gel composition (sample E) produced in Example 1 is used as the gasket 1.
Therefore, the gasket 1 of this example can exhibit conductivity without applying a load thereto. Therefore, it is possible to reliably take EMC measures. Moreover, since the gasket 1 has the outstanding softness | flexibility, it can absorb the impact from the outside. Therefore, the liquid crystal display panel 65 can be protected from impact.

Explanatory drawing which shows a mode that the resonance magnification of the conductive gel composition (sample E) and conductive elastomer (sample C) concerning Example 1 is measured. The diagram which shows the resonance curve of the conductive gel composition (sample E) and conductive elastomer (sample C) concerning Example 1. FIG. FIG. 3 is an enlarged explanatory view showing a maximum (resonance magnification peak) portion of a resonance magnification of sample E in FIG. 2. Explanatory drawing which shows the outline of the electrical conductivity test concerning Example 1. FIG. (A) Explanatory drawing which shows the structure of a microphone holder concerning Example 2, (b) Explanatory drawing which shows a mode that the microphone holder was mounted in the housing | casing, (c) On the electronic component (board | substrate) connected with a microphone holder Explanatory drawing which shows the pattern of the formed metal electrode. (A) Explanatory drawing which shows the back surface side of one housing | casing of an electronic device (mobile phone) concerning Example 3, (b) Explanatory drawing which shows the inside of the other housing | casing of an electronic device (mobile phone). The side view which shows a mode that two housings | casings of the electronic device (mobile phone) concerning Example 3 were bonded together. Explanatory drawing which shows the internal structure of the electronic device (cellular phone) concerning Example 4. FIG. FIG. 9 is a cross-sectional view taken along line AA in FIG. 8. The front view of the electronic device (liquid crystal television) concerning Example 5. FIG. FIG. 11 is a cross-sectional view taken along line B-B in FIG. 10.

Explanation of symbols

  1 Conductive gel composition

Claims (3)

A conductive gel composition containing a base resin composed of a styrene elastomer, a softening agent, and a conductive filler,
The conductive gel composition contains 400 to 1500 parts by weight of the softening agent and 500 to 3000 parts by weight (excluding 500 parts by weight) of the conductive filler with respect to 100 parts by weight of the base resin. And the durometer hardness is A40 or less, The electroconductive gel composition characterized by the above-mentioned.   The conductive gel composition according to claim 1, wherein the conductive filler has an aspect ratio of 1 to 5. 3. The conductive gel composition according to claim 1 , wherein the conductive filler contains 1100 parts by weight or more of the conductive filler with respect to 100 parts by weight of the base resin .

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