JP4497303B2 - Polyamide resin composition and damping material - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention is a resin composition that is useful as a vibration damping material and a sound absorbing and insulating material and has a high vibration damping property, that is, a property that attenuates vibration energy by converting vibration energy from outside into thermal energy, and uses the same. Related to vibration damping materials.

  Conventionally, a soft vinyl chloride resin in which a plasticizer is added to a vinyl chloride resin is known as a material that absorbs vibration energy such as a vibration damping material. This soft vinyl chloride resin has been designed to attenuate vibration energy by consuming it as frictional heat inside the resin, but it has not been able to absorb or attenuate vibration energy sufficiently.

  As the vibration damping material, rubber materials such as butyl rubber and NBR, which are excellent in terms of workability, mechanical strength and material cost, are often used. However, although this rubber material has the most excellent damping properties (vibration energy transmission insulation performance or transmission relaxation performance) among general polymers, the rubber material alone is used as a vibration damping material. For example, for vibration control of buildings and equipment, for example, a laminated body in which rubber materials and steel plates are laminated, or a lead core that plastically deforms to absorb vibration energy and an oil damper are combined. It was used in a complex form called a vibration structure.

  The rubber material as a conventional vibration damping material cannot be used alone as described above, and has been forced to be combined, so the vibration damping structure is inevitably complicated. Their own high vibration control was required.

  In addition, a composition mainly composed of a polymer material and a piezoelectric powder material is disclosed (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1). A composition of a polymer material and a piezoelectric powder converts vibration energy into electric energy by piezoelectricity, consumes the generated electric energy by Joule heat, and absorbs and attenuates vibration. However, in this composition, sufficient vibration damping properties cannot be obtained unless blended so as to contain 50% by mass or more of piezoelectric particles. However, when blended in such a composition, the fluidity in the molten state is lowered, and kneading or Molding becomes difficult. Further, since ceramics such as lead zirconate titanate and barium titanate are used for the piezoelectric particles, there is a disadvantage that the mass is increased.

  In addition, a vibration damping film made of a piezoelectric film and a conductive layer formed on the film surface has been proposed (see, for example, Patent Document 3). However, only a polyvinylidene fluoride polymer is used as a piezoelectric film in practical use. Polyvinylidene fluoride-based polymers are expensive, and in addition, film formation is difficult, and it is difficult to produce a large-area film in large quantities, so that they have not been put into practical use as a vibration damping film. Further, as an example using a piezoelectric film that is inexpensive and easy to form, a vibration damping material using a piezoelectric film using a polyamide polymer has also been proposed (see, for example, Patent Document 4 and Patent Document 5). . However, in order to express the piezoelectricity in the film, a polarization process is required. Therefore, a special apparatus is required for the production, and there is a problem that the production cost increases.

Moreover, the damping material in which the active ingredient which increases the amount of dipole moments in the polymer base material is also disclosed (see, for example, Patent Document 6, Patent Document 7, and Non-Patent Document 2). However, the active ingredient used in this material is a low-molecular compound, and has a drawback that it is oozed out from the base material during use and the performance is lowered.
JP-A-60-51750 Japanese Patent Laid-Open No. 3-188165 JP-A-5-87186 JP-A-8-305369 Japanese Patent Laid-Open No. 9-309962 Japanese Patent No. 3318593 Japanese Patent No. 3192400 Inaba et al., “Relationship between Mechanical Properties and Damping Performance of Piezoelectric Damping Composites”, Journal of Japan Rubber Association, Vol. 67, p. 564 (1994) Inoue et al., “Damping behavior of chlorinated polyethylene / N, N′-dicyclohexyl-2-benzothiazylsulfenamide-based organic hybrid”, Journal of Textile Society of Japan, 56, 443 (2000)

  An object of the present invention is to provide a material that is mainly made of a polymer material, can be easily manufactured, is lightweight, and has higher vibration damping properties.

  By dispersing a conductive material in a ferroelectric polymer, the present inventors have achieved high damping performance based on piezoelectricity in a minute unit without expressing macro piezoelectricity by applying polarization treatment. We studied based on the idea that it is possible to express As a result, a composition in which a conductive material is dispersed in a polyamide with a specific structure that has excellent performance as a ferroelectric polymer does not require polarization treatment, has excellent moldability, is inexpensive, and has high vibration damping properties. The present invention has been found out and has been achieved.

That is, the present invention is obtained by polycondensation of a diamine component containing 50 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of azelaic acid, and subjecting the stretched film to polarization treatment with an electric field of 200 MV / m. The present invention relates to a resin composition comprising a ferroelectric polyamide having a remanent polarization of 30 mC / m ² or more and a conductive material. Furthermore, the present invention relates to a vibration damping material comprising the resin composition and a sound absorbing and insulating material comprising the resin composition. The resin composition according to the present invention is suitably used as a vibration damping material and a sound absorbing and insulating material for various mechanical devices, building structures, vehicles and aircraft structures.

  Since the resin composition of the present invention does not require a polarization treatment, it can be easily produced, is a light weight material having higher vibration damping properties, and the industrial significance of the present invention is great.

  The ferroelectric polyamide used in the resin composition of the present invention is a polyamide obtained by polycondensation using metaxylylenediamine as a main diamine component and azelaic acid as a main dicarboxylic acid component. It is necessary to contain 50 mol% or more of metaxylylenediamine and 50 mol% or more of azelaic acid, and preferably 70 mol% or more of metaxylylenediamine and 70 mol% or more of azelaic acid. If any of the components is less than 50 mol%, the ferroelectricity becomes small and sufficient vibration damping properties cannot be obtained when a composition with a conductive material is obtained.

The polyamide used in the resin composition of the present invention has a residual polarization of 30 mC / m ² or more as a ferroelectric polymer when the stretched film is polarized with an electric field of 200 MV / m. When the residual polarization is less than 30 mC / m ² , sufficient vibration damping properties cannot be obtained when the resin composition is used. Here, the stretched film used when measuring the remanent polarization is obtained by stretching a film having a thickness of 10 to 300 μm uniaxially or biaxially at a stretch ratio of 2.0 times or more. If necessary, the stretched film may be heat-treated for 10 to 30 seconds at a temperature not lower than the glass transition temperature and not higher than the melting point while maintaining a tension state. However, if the residual polarization is reduced by the heat treatment, the heat treatment is not performed. .

  A diamine other than metaxylylenediamine may be used within a range of 50 mol% or less of the total diamine component. Examples of diamines other than metaxylylenediamine used in the present invention include 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, and 1,8-octane. Diamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexane Diamine, 2-methyl-1,5-pentanediamine, paraxylylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4 -Diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2-bis (4-aminocyclohexyl) Propane, isophorone diamine, p-phenylenediamine, meta-phenylenediamine, bis (4-aminophenyl) ether, bis (4-aminophenyl) methane, and the like.

  A dicarboxylic acid other than azelaic acid may be used within a range of 50 mol% or less of the total dicarboxylic acid component. Examples of dicarboxylic acids other than azelaic acid used in the present invention include glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassic acid, terephthalic acid, isophthalic acid, phthalic acid 2-methyl terephthalic acid, naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, benzophenone dicarboxylic acid, tetralin dicarboxylic acid, decalin dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic acid, norbornane dicarboxylic acid, tricyclodecane Examples thereof include dicarboxylic acid, pentacyclododecanedicarboxylic acid, isophorone dicarboxylic acid, and polymerized fatty acid.

  Moreover, you may use amide bond production | generation compounds, such as aminocarboxylic acid, in the range which does not exceed 50 mol% of a repeating unit with respect to the whole amide bond repeating unit. Examples of amide bond-forming compounds such as aminocarboxylic acids used in the present invention include γ-butyrolactam, δ-valerolactam, ε-caprolactam, ω-laurolactam, 5-aminopentanoic acid, 6-aminohexanoic acid, Examples include 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

  Among the copolymer components as described above, 1,5-pentanediamine, 1,7-heptanediamine, 1,9-nonanediamine, 2-methyl-1,5-pentanediamine, 1,3-bis (aminomethyl) Cyclohexane, glutaric acid, suberic acid, undecanedioic acid, isophthalic acid, 1,3-cyclohexanedicarboxylic acid, δ-valerolactam, 5-aminopentanoic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid Is particularly preferred, and the resin composition of the present invention exhibits greater vibration damping properties when it is a copolymer containing one or more selected from these.

  The present invention is also applicable to the case where the copolymerization component is a dicarboxylic acid component and a diamine component, each of which is 10 mol% or less, that is, metaxylylenediamine in the diamine component and azelaic acid in the dicarboxylic acid component are each 90 mol% or more. The resin composition exhibits greater vibration damping properties.

  There is no restriction | limiting in particular in the method of manufacturing the polyamide used for the resin composition of this invention, A conventionally well-known method is applicable.

  Depending on the production method, dicarboxylic acid components such as dicarboxylic acid esters, dicarboxylic acid chlorides, active acyl derivatives, and dinitriles can be used as the raw material for the dicarboxylic acid component, depending on the production method. In addition to the diamine, diamine derivatives such as N-acetyldiamine, diisocyanate, and N-silylated diamine can also be used as the diamine component.

The example of the manufacturing method of the polyamide used for the resin composition of this invention is shown below.
Raise the temperature of the diamine component containing 50 mol% or more of metaxylylenediamine, the dicarboxylic acid component containing 50 mol% or more of the azelaic acid and the diamine component, and water to the temperature at which the amidation reaction occurs in the autoclave. Then, the amidation reaction is allowed to proceed by maintaining the pressure under steam for a predetermined time. Next, the exhaust valve is opened to release water vapor, and the internal temperature is raised above the melting point of the polyamide while returning to normal pressure. After holding for a predetermined time, the polyamide is taken out. A diamine component and an aliphatic dicarboxylic acid component can be added in the form of a nylon salt instead of being added individually. Further, a part or all of the dicarboxylic acid component may be used in the form of the corresponding lower alkyl ester.

Another example of the method for producing the polyamide used in the resin composition of the present invention is shown below.
A dicarboxylic acid component containing 50 mol% or more of azelaic acid is heated in a reaction vessel, and after azelaic acid is melted, a diamine component containing 50 mol% or more of metaxylylenediamine is continuously stirred while stirring the contents. Dripping. During this time, the internal temperature is continuously raised above the melting point of the contents. The water distilled with the addition of the diamine component is removed out of the reaction system through a condenser and a cooler. After a predetermined amount of the diamine component is dropped, the reaction is further continued for a predetermined time, and then the polyamide is taken out.

  If it is necessary to further increase the molecular weight, the polyamide obtained by melt polymerization can be subjected to solid phase polymerization to increase the molecular weight.

  Various additives such as a polymerization catalyst, an antioxidant, a heat stabilizer, an ultraviolet absorber, and an antistatic agent may be added to the polyamide used in the resin composition of the present invention before and after the polymerization reaction.

  The resin composition of the present invention contains a specific ferroelectric polyamide and a conductive material. The resistance value is adjusted by a conductive material, and electric energy generated in a minute domain of the ferroelectric polyamide is efficiently converted into heat energy and consumed. As the conductive material, a known material can be used. For example, in inorganic systems, copper, copper alloy, silver, nickel, metal powder and metal fiber of low melting point alloy, copper and silver fine particles coated with noble metal, fine particles of metal oxide such as tin oxide, zinc oxide and indium oxide, Whisker, various carbon blacks, conductive carbon powders such as carbon nanotubes, PAN-based carbon fibers, pitch-based carbon fibers, carbon fibers such as vapor-grown graphite, organic-based low-molecular surfactant type antistatic agents, polymer-based Examples thereof include antistatic agents, conductive polymers such as polypyrrole and polyaniline, and polymer fine particles coated with metal. Further, both inorganic conductive materials and organic conductive materials can be used. Among these, it is preferable to use at least one carbon material.

  The addition amount of the conductive material is preferably 0.01 to 25% by weight. If the amount of the conductive material added is too small, the consumption of electric energy becomes insufficient, and if it is too large, the performance deteriorates by the amount of unnecessary conductive material that does not affect the consumption of electric energy.

The blending ratio of the ferroelectric polyamide and the conductive material is preferably adjusted so that the volume resistivity of the resin composition is 10 ¹² Ω · cm or less. When the volume resistivity is 10 ¹² Ω · cm or less, the electric energy generated by the electromechanical conversion action can be efficiently consumed by Joule heat.

  The resin composition of the present invention is mainly composed of a polyamide having ferroelectricity and a conductive material. However, the resin composition is not limited to one composed only of a ferroelectric polyamide and a conductive material. For the purpose of improving vibration energy absorption, it is preferable to add one or more inorganic fillers that exhibit a loss effect due to friction. Examples of the inorganic filler include glass pieces, glass beads, glass balloons, glass fibers, carbon fibers, calcium carbonate, alumina, aluminum hydroxide, zinc oxide, barite, precipitated barium sulfate, wollastonite, potassium titanate, sepiolite, and zonotlite. , Magnesium sulfate, titanium oxide, silica, barium sulfate and the like, but are not limited thereto. Among them, it is preferable to add a scaly filler. Examples of scaly fillers include mica, talc, sericite, kaolinite, montmorillonite, such as mascobite (muscovite), phlogopite (phlogopite), biotite (biotite), and fluorine phlogopite (artificial mica). Examples include, but are not limited to, flaky glass flakes and flaky boehmite. Mica is particularly preferred as the scale-like filler.

  The amount of the inorganic filler added is preferably 20 to 80% by weight, and more preferably 30 to 75% by weight. If the added amount of the inorganic filler is too small, the effect of adding the inorganic filler is insufficient, and if it is too large, the addition becomes difficult.

  If necessary, one or more additives, for example, a dispersant, a compatibilizer, a surfactant, an antistatic agent, a lubricant, a plasticizer, a flame retardant, a crosslinking agent, an antioxidant, an anti-aging agent, Weathering agents, heat-resistant agents, processing aids, brighteners, colorants (pigments, dyes), foaming agents, foaming aids and the like can be added as long as the effects of the present invention are not impaired. Also, blending with other resins or surface treatment after molding can be performed within a range that does not impair the effects of the present invention.

  The composition of the present invention can be obtained by mixing a ferroelectric polyamide, a conductive material and, if necessary, a filler and other additives. In that case, a heat roll, a Banbury mixer, a twin-screw kneader A known melt-mixing device such as an extruder can be used. Further, a method of dissolving or swelling the above-mentioned ferroelectric polyamide in a solvent, mixing a conductive material and a filler if necessary, and drying, a method of mixing each component in a fine powder form, etc. are also adopted. Can do. In addition, there are no particular limitations on the addition method, the order of addition, and the like of conductive materials, fillers, additives, and the like.

  The composition of the present invention can be used in the form of injection molded products, sheets, films, fibers, foams, adhesives, paints, constraining sheets, unconstrained sheets, etc. as vibration damping materials and sound absorbing and insulating materials, It can be suitably used as a vibration-damping material and a sound-absorbing and sound-insulating material for vehicles, railways, aircraft, home appliances / OA equipment, precision equipment, construction machinery, civil engineering buildings, precision equipment, shoes, sports equipment and the like.

Examples are shown below, but the present invention is not limited to the following examples. The physical properties were measured by the following method.
(1) Residual polarization Ferroelectric polyamide is melt-molded by a known method to form a film having a thickness of about 50 to 200 μm. This film is uniaxially or biaxially stretched. If necessary, the stretched film may be heat-treated for 10 to 30 seconds at a temperature not lower than the glass transition temperature and not higher than the melting point while maintaining a tension state. However, if the residual polarization is reduced by the heat treatment, the heat treatment is not performed. . 5 mm × 8 mm of aluminum was vapor-deposited on both sides of the obtained stretched film having a thickness of 15 to 20 μm by using a JEE-400 type vacuum vapor deposition device manufactured by JEOL Ltd. to obtain an electrode. Using a hysteresis measuring device manufactured by Toyo Seiki Seisakusho Co., Ltd., applying a sinusoidal electric field of 0.1 Hz at a maximum of 200 MV / m between the electrodes on both sides of the film, the polarization D obtained by integrating the current flowing with a charge amplifier. The measurement was plotted against the electric field E, and the value of D at the time of E = 0 was obtained from the hysteresis curve to obtain the residual polarization. Residual polarization was obtained from a hysteresis curve in which the polarization D at this time was plotted against the electric field E.
(2) Volume resistivity The resin composition was molded on a disk having a diameter of about 100 mm and a thickness of about 2 mm to prepare a sample.
It was measured by the method of JIS K6911.
(3) Damping property Damping property was evaluated by the loss elastic modulus of dynamic viscoelasticity. The greater the loss elastic modulus, the higher the damping performance. The resin composition was molded at 260 ° C. by hot pressing to obtain a sheet having a thickness of about 1 mm. The obtained sheet | seat was cut out to 5 mm x 25 mm, and it was set as the test piece. The obtained test piece was subjected to conditions of 0 to 100 ° C., a temperature rising rate of 2 ° C./min, and a frequency of 13 Hz using a dynamic viscoelasticity measuring apparatus (Rheograph Solid S-1 manufactured by Toyo Seiki Seisakusho Co., Ltd.). And evaluated by the peak value of the obtained loss modulus.

<Example 1>
90 parts by weight of polyamide obtained by polycondensation of metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Inc.) and EMEROX 1144 (cocarboxylic acid 99.97%, azelaic acid 93.3 mol%), and conductive carbon 10 parts by weight of powder (made by Ketjen Black International Co., Ltd., trade name Ketjen Black EC) was kneaded at 260 ° C. using a twin screw extruder. The obtained resin composition was measured and evaluated for volume resistivity and vibration damping property (peak value of loss elastic modulus). The results are shown in Table 1. In addition, the stretched film used for the residual polarization measurement was produced by the following method. Using a single-axis extruder (screw diameter: 20 mm, L / D: 25, screw type: full flight), ferroelectric polyamide is cylinder temperature 255-265 ° C., T die temperature 260 ° C., screw rotation speed by T-die method. A film having a thickness of about 50 μm was obtained under the condition of 50 rpm. This film was preheated at 90 ° C. for several seconds using a biaxial stretching machine manufactured by Toyo Seiki Seisakusho Co., Ltd., and then uniaxially stretched in the extrusion direction under conditions of a stretching ratio of 3 times. Next, the stretched film was heat-treated for 10 seconds in an atmosphere of 200 ° C. while maintaining a tension state. The residual polarization was measured using the obtained stretched film having a thickness of 15 to 20 μm. The results are shown in Table 1.

<Comparative Example 1>
Using a polyamide obtained by polycondensation of metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) and Cognis EMEROX 1144 (dicarboxylic acid 99.97%, azelaic acid 93.3 mol%), volume resistivity, control Vibration (peak value of loss modulus) was measured and evaluated. The results are shown in Table 1. The remanent polarization is the same as in Example 1.

<Example 2>
Metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) and Cognis EMEROX 1144 (dicarboxylic acid 99.97%, azelaic acid 93.3 mol%) / isophthalic acid (manufactured by EI International Chemical Co., Ltd.) (mol) 90 parts by weight of polyamide obtained by polycondensation of the ratio 75/25) and 10 parts by weight of conductive carbon powder (trade name Ketjen Black EC, manufactured by Ketjen Black International Co., Ltd.) using a twin screw extruder. And kneaded at 260 ° C. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 1. The stretched film used for the measurement of remanent polarization was produced in the same manner as in Example 1, and the remanent polarization was measured. The results are shown in Table 1.

<Comparative example 2>
Metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) and Cognis EMEROX 1144 (dicarboxylic acid 99.97%, azelaic acid 93.3 mol%) / isophthalic acid (manufactured by EI International Chemical Co., Ltd.) (mol) The volume resistivity and vibration damping properties (peak value of loss elastic modulus) were measured and evaluated using a polyamide obtained by polycondensation (ratio: 75/25). The results are shown in Table 1. The remanent polarization is the same as in Example 2.

<Comparative Example 3>
Volume resistivity and vibration damping (peak value of loss elastic modulus) were measured and evaluated using nylon 6 (manufactured by Ube Industries, Ltd., trade name: UBE nylon 1024B). The results are shown in Table 1. In addition, the stretched film used for the residual polarization measurement was produced by the following method. Using a single-screw extruder (screw diameter: 20 mm, L / D: 25, screw shape: full flight), using a T-die method under conditions of a cylinder temperature of 240 to 250 ° C., a T die temperature of 245 ° C., and a screw rotation speed of 50 rpm. A film having a thickness of about 50 μm was obtained. This film was preheated at 90 ° C. for several seconds using a biaxial stretching machine manufactured by Toyo Seiki Seisakusho Co., Ltd., and then uniaxially stretched in the extrusion direction under the condition of a stretching ratio of 3.5. Next, the stretched film was heat-treated for 10 seconds in an atmosphere of 200 ° C. while maintaining a tension state. The residual polarization was measured using the obtained stretched film having a thickness of 15 to 20 μm. The results are shown in Table 1.

<Comparative example 4>
90 parts by weight of the resin used in Comparative Example 3 and 10 parts by weight of conductive carbon powder (trade name, Ketjen Black EC, manufactured by Ketjen Black International Co., Ltd.) were kneaded at 260 ° C. using a twin screw extruder. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 1.

<Comparative Example 5>
Using a nylon 6/66/610/12 resin (manufactured by Toray Industries, Inc., trade name: Amilan CM8000), volume resistivity and vibration damping properties (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 1. In addition, the stretched film used for the residual polarization measurement of polyamide was produced by the following method. Using a single screw extruder (screw diameter: 20 mm, L / D: 25, screw shape: full flight), using a T-die method under conditions of cylinder temperature 250 to 265 ° C., T die temperature 260 ° C., screw rotation speed 50 rpm. A film having a thickness of about 50 μm was obtained. This film was preheated at 90 ° C. for several seconds using a biaxial stretching machine manufactured by Toyo Seiki Seisakusho Co., Ltd., and then uniaxially stretched in the extrusion direction under conditions of a stretching ratio of 3.0. Next, the stretched film was heat-treated for 10 seconds in an atmosphere of 200 ° C. while maintaining a tension state. The residual polarization was measured using the obtained stretched film having a thickness of 15 to 20 μm. The results are shown in Table 1.

<Comparative Example 6>
90 parts by weight of the resin used in Comparative Example 5 and 10 parts by weight of conductive carbon powder (trade name, Ketjen Black EC, manufactured by Ketjen Black International Co., Ltd.) were kneaded at 260 ° C. using a twin screw extruder. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 1.

表１に示すように、比較例１，２と比較して、実施例１，２の本発明による樹脂組成物は、高い損失弾性率を示し，制振性が高かった。また、比較例３〜６で本発明で用いるポリアミド以外のポリアミドを使った場合では、導電性材料を加えても高い損失弾性率を示さず，制振性が低かった。

As shown in Table 1, as compared with Comparative Examples 1 and 2, the resin compositions according to the present invention of Examples 1 and 2 showed high loss elastic modulus and high vibration damping properties. In addition, when a polyamide other than the polyamide used in the present invention was used in Comparative Examples 3 to 6, a high loss elastic modulus was not exhibited even when a conductive material was added, and the vibration damping property was low.

<Example 3>
36 parts by weight of polyamide obtained by polycondensation of metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Co., Inc.) and EMEROX 1144 (cocarboxylic acid 99.97%, azelaic acid 93.3 mol%), and conductive carbon Batch type twin-screw kneader with 4 parts by weight of powder (made by Ketjen Black International Co., Ltd., trade name Ketjen Black EC) and 60 parts by weight of mica (Muskobite: made by Yamaguchi Mica Co., Ltd., trade name: B-82) And kneaded at 260 ° C. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 2.

<Example 4>
Metaxylylenediamine (Mitsubishi Gas Chemical Co., Ltd.) and Cognis EMEROX 1144 (dicarboxylic acid 99.97%, azelaic acid 93.3 mol%) / isophthalic acid (manufactured by EI International Chemical Co., Ltd.) (mol) 36: part by weight of polyamide obtained by polycondensation of 75/25), 4 parts by weight of conductive carbon powder (trade name Ketjen Black EC manufactured by Ketjen Black International Co., Ltd.) and mica (mascobite: 60 parts by weight of Yamaguchi Mica Co., Ltd., trade name: B-82) were kneaded at 260 ° C. using a batch type biaxial kneader. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 2.

<Comparative Example 7>
36 parts by weight of nylon 6 (manufactured by Ube Industries, trade name: UBE nylon 1024B), 4 parts by weight of conductive carbon powder (trade name, ketjen black EC, made by Ketjen Black International Co., Ltd.) and mica (mascobite) : Yamaguchi Mica Co., Ltd., trade name: B-82) 60 parts by weight were kneaded at 260 ° C. using a batch type biaxial kneader. Using the obtained resin composition, volume resistivity and vibration damping property (peak value of loss elastic modulus) were measured and evaluated. The results are shown in Table 2.

Claims (12)

Residual polarization obtained by polycondensing a diamine component containing 50 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 50 mol% or more of azelaic acid, and subjecting the stretched film to a polarization treatment at an electric field of 200 MV / m A resin composition comprising: a ferroelectric polyamide having a conductivity of 30 mC / m ² or more and a conductive material. The resin composition according to claim 1, wherein the ferroelectric polyamide is a polyamide obtained by polycondensation of a diamine component containing 70 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 70 mol% or more of azelaic acid. Ferroelectric polyamide is 1,5-pentanediamine, 1,7-heptanediamine, 1,9-nonanediamine, 2-methyl-1,5-pentanediamine, 1,3-bis (aminomethyl) cyclohexane, glutaric acid , Suberic acid, undecanedioic acid, isophthalic acid, 1,3-cyclohexanedicarboxylic acid, δ-valerolactam, 5-aminopentanoic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, and 11-aminoundecanoic acid The resin composition according to claim 1, which is a polyamide obtained by using one or more selected from the above as a copolymerization component. The resin composition according to claim 1 or 2, wherein the ferroelectric polyamide is a polyamide obtained by polycondensation of a diamine component containing 90 mol% or more of metaxylylenediamine and a dicarboxylic acid component containing 90 mol% or more of azelaic acid. . The resin composition according to claim 1, wherein the conductive material contains at least one kind of carbon material. The resin composition according to any one of claims 1 to 5, wherein the resin composition contains 0.01 to 25% by weight of a conductive material. The resin composition according to claim 1, wherein the volume resistivity is 10 ¹² Ω · cm or less. The resin composition according to claim 1, comprising a ferroelectric polyamide, a conductive material, and an inorganic filler. The resin composition according to claim 8, wherein the inorganic filler is a scaly filler. The resin composition according to claim 8 or 9, wherein the resin composition contains 20 to 80% by weight of an inorganic filler. A vibration damping material comprising the resin composition according to claim 1. A sound absorbing and insulating material comprising the resin composition according to claim 1.