Conductive resin composition, master batch, molded article, and method for producing same

Abstract

Provided are: a molded body having high electromagnetic wave shielding properties or conductivity without deteriorating mechanical properties; a conductive resin composition and a master batch which provide the molded body; and methods for producing the same. More specifically, provided are: a conductive resin composition obtained by melt-kneading, as essential raw materials, a thermoplastic resin and a carbon nanostructure obtained by bonding carbon nanotubes and glass fibers with a binder resin, a master batch capable of providing the same, and a method for producing the conductive resin composition, the master batch, and the method for producing the conductive resin composition, the master batch, and the method for producing the conductive resin composition, the master batch, and the method for producing the same. The conductive resin composition contains 0.1-30 parts by mass of the carbon nanostructures per 100 parts by mass of the thermoplastic resin.

Description

Technical Field

[0001] The present invention relates to a conductive resin composition, a masterbatch, a molded body, and methods for producing the same. Background Art

[0002] 5G communication technology and millimeter wave radar are becoming popular, and on the other hand, noise suppression at high frequencies is being studied. In high-frequency shielding materials, molded materials are sometimes used for housings and sheets of electrical equipment. However, in composites of magnetic metals such as ferrite, electromagnetic wave shielding at high frequencies is difficult, and in composites of carbon black, high concentrations need to be added to exert electromagnetic wave shielding, which has the problem of reduced mechanical properties such as impact resistance.

[0003] Therefore, although it is desired to use carbon nanotubes that can exhibit high electromagnetic wave shielding properties without impairing mechanical properties, there is a problem that it is difficult to disperse carbon nanotubes when kneading with resin materials, and it is difficult to achieve the expected electromagnetic wave shielding properties.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-108524 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] Therefore, an object of the present invention is to provide a molded body having high electromagnetic wave shielding properties or electrical conductivity without impairing mechanical properties, a conductive resin composition and a masterbatch therefor, and methods for producing the same.

[0009] Solutions for solving problems

[0010] The conductive resin composition, masterbatch, molded article and methods for producing the same according to the present invention are as follows [1] to [9].

[0011] [1] A conductive resin composition, characterized in that it is prepared by melt-kneading a thermoplastic resin and a carbon nanostructure as essential raw materials,

[0012] The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin.

[0013] The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0014] [2] The conductive resin composition according to [1], wherein the carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a binder resin to form a cross-linked structure.

[0015] [3] The conductive resin composition according to [1] or [2], which is a masterbatch,

[0016] The carbon nanostructure is contained in an amount of 1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0017] [4] The conductive resin composition according to any one of [1] to [3], wherein the thermoplastic resin includes at least one selected from the group consisting of polyamide resins, polyethylene resins, polypropylene resins, and polyphenylene resins.

[0018] [5] A molded product obtained by molding the conductive resin composition according to any one of [1] to [4].

[0019] [6] The molded article according to [5], which is a conductive material or an electromagnetic wave shielding material.

[0020] [7] A method for producing a conductive resin composition, comprising the steps of melt-kneading a thermoplastic resin and a carbon nanostructure,

[0021] The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin.

[0022] The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0023] [8] A method for producing a conductive resin composition, comprising the step of melt-kneading a thermoplastic resin and a carbon nanostructure in a ratio of 0.1 to 30 parts by mass of the carbon nanostructure to 100 parts by mass of the thermoplastic resin to produce a masterbatch,

[0024] The method further comprises the step of melt-kneading the obtained masterbatch and a thermoplastic resin.

[0025] [9] A method for producing a molded article, comprising the steps of melt-molding a conductive resin composition containing a thermoplastic resin and a carbon nanostructure,

[0026] The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin.

[0027] The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0028] Effects of the Invention

[0029] According to the present invention, there can be provided a molded body having high electromagnetic wave shielding properties or electrical conductivity without impairing mechanical properties, a conductive resin composition and a masterbatch providing the molded body, and methods for producing the molded body and the masterbatch. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The Raman spectra of the fillers used in Examples 1 to 6 (excitation wavelength: 633 nm) are shown.

[0031] Figure 2 The Raman spectra of the fillers used in Examples 1 to 6 (excitation wavelength: 785 nm) are shown. DETAILED DESCRIPTION

[0032] The preferred embodiment of the present invention is described below. It should be noted that in this specification, "X to Y" indicating a range means "above X and below Y". In addition, in this specification, unless otherwise specified, operations and measurements of physical properties are performed under the conditions of room temperature (20 to 25°C) / relative humidity 40 to 50% RH.

[0033] The conductive resin composition of the present invention is characterized in that it is prepared by melt-kneading a thermoplastic resin and a carbon nanostructure as essential raw materials.

[0034] The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin.

[0035] The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0036] Thermoplastic resin

[0037] The thermoplastic resin used in the present invention is not particularly limited. It can be considered that the type of carbon nanostructures to be compounded, the product quality required when forming a molded body, etc., are suitably selected from known resins and used. The thermoplastic resin used in the present invention can use only one kind, or it can mix two or more kinds and use. When mixing two or more kinds, it is preferred to use resins with high compatibility in combination. Furthermore, the thermoplastic resin can use commercially available products, or it can use synthetic products.

[0038] Specific examples of the thermoplastic resin used in the present invention include: polyolefin resins such as polyethylene, polypropylene, poly(4-methyl-1-pentene), and poly(1-butene); polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyamide resins such as polyamide-6 (nylon-6), polyamide 66 (nylon-66), and poly(m-xylylene adipamide); ethylene-unsaturated ester copolymers such as ethylene-vinyl ester copolymers and ethylene-unsaturated carboxylic acid ester copolymers; Unsaturated carboxylic acid copolymers or ionomer resins thereof; poly(meth)acrylic acid resins such as poly(meth)acrylate resins; chlorine resins such as polyvinyl chloride and polyvinylidene chloride; fluorine resins such as polytetrafluoroethylene, ethylene tetrafluoroethylene copolymers, polyvinylidene fluoride, and polyethylene fluoride; polystyrene resins; polyether resins such as polyetheretherketone resins and polyetherketone resins; polycarbonate resins; polyphenylene resins such as polyarylene sulfide resins represented by polyphenylene ether resins and polyphenylene sulfide resins; polyvinyl acetate resins; polyacrylonitrile resins; thermoplastic elastomers, etc. Among them, polyolefin resins, polyester resins, polyamide resins, and polyolefin resins can be cited as preferred examples. In addition, one selected from these thermoplastic resins can be used alone, or two or more selected from these thermoplastic resins can be used in combination.

[0039] The polyolefin-based resin is a polyolefin resin obtained by polymerizing at least one type of olefin, and may be a homopolymer or a copolymer.

[0040] Examples of such olefins include ethylene, propylene, isobutylene, α-olefins having 4 to 12 carbon atoms including isobutylene (1-butene), butadiene, isoprene, (meth)acrylates, (meth)acrylic acid, (meth)acrylamide, vinyl alcohol, vinyl acetate, vinyl chloride, styrene, and acrylonitrile.

[0041] Examples of α-olefins having 4 to 12 carbon atoms include 1-butene, 2-methyl-1-propylene, 2-methyl-1-butylene, 3-methyl-1-butylene, 1-hexene, 2-ethyl-1-butylene, 2,3-dimethyl-1-butylene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butylene, 1-heptene, 1-methyl-1-pentene, 1-octene, methyl-1-pentene, ethyl-1-hexene, dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-undecene, 1-dodecene and the like.

[0042] As polyolefin resins, for example, polyethylene resins, polypropylene resins, polyisobutylene resins, polyisobutene resins, polyisoprene resins, polybutadiene resins, etc. can be cited. Among these resins, polyethylene resins and polypropylene resins are preferred. When classified by density or shape, high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-low-density polyethylene (VLDPE), linear low-density polyethylene (LLDPE), and ultra-high molecular weight polyethylene (UHMW-PE) can be cited, among which high-density polyethylene is preferred.

[0043] Carbon Nanostructures

[0044] The carbon nanostructure used in the present invention is formed by bonding carbon nanotubes and glass fibers with a bonding resin. The aforementioned carbon nanostructure is preferably formed by bonding carbon nanotubes and glass fibers with a bonding resin to have a network structure. The aforementioned carbon nanostructure is preferably formed by bonding carbon nanotubes and glass fibers with a bonding resin to form a branched structure, a structure intermixed with each other, a structure entangled with each other, or a cross-linked structure, and the aforementioned structure may also be in the shape of a dendritic macromolecule. Regarding the respective proportions of carbon nanotubes, glass fibers, and bonding resin, relative to the total of carbon nanotubes, glass fibers, and bonding resin, the proportion of carbon nanotubes is preferably 70 to 98% by mass, the proportion of glass fibers is preferably 1 to 15% by mass, and the proportion of bonding resin is preferably 1 to 15% by mass.

[0045] As the carbon nanotube, a single-walled carbon nanotube (SWCNT) having an average diameter of 5 to 100 nanometers (nm) or a multi-walled carbon nanotube (MWCNT) in which multiple layers (two or more layers) of the single carbon nanotube are connected can be used.

[0046] The glass fiber may be obtained by melting a glass component mainly composed of silicon dioxide (SiO2), cooling it, and forming a fine powder. Examples of the glass fiber include glass powder (e.g., glass powder shown in CAS 65997-17-3, quasi-drug raw material standard product) and the like.

[0047] The carbon nanostructure used in the present invention is preferably a composite of carbon nanotubes (CNTs) having a G / D ratio of 0.5 to 1.0 at an excitation wavelength of 633 nm and a G / D ratio of 0.1 to 0.5 at an excitation wavelength of 785 nm as shown in Raman spectroscopy, and glass powder. It should be noted that "G" and "D" are respectively the carbon nanotubes having a G / D ratio of 0.5 to 1.0 at an excitation wavelength of 633 nm and a G / D ratio of 0.1 to 0.5 at an excitation wavelength of 785 nm in Raman spectroscopy. -1 Nearby, 1367cm -1 The height of the peaks that appear nearby.

[0048] As the binder resin, any known substance can be used as long as it is used as a sizing agent for carbon fiber or glass fiber. Further specific examples include, but are not limited to, fluorinated polymers such as poly(vinyl difluoride) (PVDF), poly(vinyl difluoride-co-hexafluoropropylene) (PVDF-HFP), poly(tetrafluoroethylene) (PTFE), polyimide, and polyethylene oxide ( oxide), polyvinyl alcohol (PVA), cellulose, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone (PVP) and other water-soluble resins, and their copolymers and mixtures; polyurethane (PU), thermoplastic polyurethane (TPU), polyethylene glycol (PEG), epoxy resin, polyester resin, vinyl ester resin, polyetherimide resin, polyetherketoneketone resin, polyphthalimide resin, polyetherketone resin, polyetheretherketone resin, polyimide resin, phenol-formaldehyde resin, bismaleimide resin, acrylonitrile-butadiene styrene (ABS) resin, polycarbonate resin, polyethyleneimine resin, polyvinyl chloride resin, polystyrene resin, polyolefin resin, polypropylene resin, polyethylene resin, polytetrafluoroethylene resin, elastomeric resin, such as polyisoprene, polybutadiene, butyl rubber, nitrile rubber, ethylene-vinyl acetate polymer, silicone polymer and fluorosilicone polymer, and combinations thereof.

[0049] As such a carbon nanostructure, a commercially available product may be used, for example, "ATHLOS(TM) 100 Carbon Nanostructure Pellets" (Cabot Corp.) may be mentioned.

[0050] The ratio of the thermoplastic resin to the carbon nanostructure is preferably 0.1 to 30 parts by mass, more preferably 1 to 15 parts by mass, of the carbon nanostructure relative to 100 parts by mass of the thermoplastic resin.

[0051] In the conductive resin composition of the present invention, in addition to the above-mentioned essential components, known additives etc. can also be mixed as other components. Specifically, antioxidants, ultraviolet absorbers, colorants, pigments, dyes, foaming agents, lubricants, flame retardants, filling materials etc. (referred to as additives in the present invention etc.) can be cited. When other components are used as arbitrary components, their blending ratio is within the range of not damaging the effect of the present invention, and the target function can be freely adjusted by adjusting the type and amount of these components, for example, relative to 100 parts by mass of the aforementioned thermoplastic resin, for example, it can be used in the range of 10 parts by mass or less, and then it can be used in the range of 5 parts by mass or less, and then, it can also be used in the range of 1 part by mass or less.

[0052] The method for producing the conductive resin composition of the present invention comprises: a step of melt-kneading a thermoplastic resin and a carbon nanostructure as essential raw materials. The kneaded product obtained by the step may be directly melt-molded to form a molded body, or may be temporarily molded into a powder, granular, pellet, or flake-like granular material and then melt-molded to form a molded body.

[0053] The process of melt-kneading thermoplastic resin and carbon nanostructure as necessary raw materials can be carried out as follows: first, at least thermoplastic resin and carbon nanostructure are used as necessary blending components, and they are blended in the above-mentioned proportion, and then known additives are blended as needed, and then uniformly mixed in a tumbler or Henschel mixer (registered trademark) as needed, and then put into a melt-kneading extruder such as a twin-screw compounding extruder, and melt-knead in a temperature range above the melting temperature of the thermoplastic resin and above the temperature + 100 ° C, for example, above 180 ° C and below 300 ° C. Thus, a morphology (morphology) with a thermoplastic resin as a continuous phase and dispersed with a carbon nanostructure or its fragments can be formed. It should be noted that in a crystalline resin, the melting temperature of a thermoplastic resin refers to a melting point, and in an amorphous resin, the melting temperature of a thermoplastic resin refers to a softening point (glass transition point) (hereinafter, the same).

[0054] When the kneaded product is temporarily granulated, for example, the kneaded product is extruded in a strand form and then left at room temperature or immersed in water at a temperature range of 5° C. to 60° C., thereby cooling and cutting, and can be formed into a granular form such as a pellet or a flake. Thereafter, the obtained granules can be freeze-pulverized as needed to obtain a powder or granular product having a desired size.

[0055] The conductive resin composition of the present invention is preferably produced via a masterbatch.

[0056] The masterbatch of the present invention is characterized in that it is obtained by melt-kneading a thermoplastic resin and a carbon nanostructure as essential raw materials, and the carbon nanostructure is contained in an amount of 1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

[0057] The thermoplastic resin and the carbon nanostructure are the same as those described above, and the method for producing the masterbatch is the same as described above except that the blending ratio of the carbon nanostructure to the thermoplastic resin is different.

[0058] When the conductive resin composition of the present invention is produced via a masterbatch, the method for producing the conductive resin composition of the present invention further comprises a step of melting and mixing or kneading the obtained masterbatch with a thermoplastic resin as a diluent resin.

[0059] The thermoplastic resin used as the diluent resin may be the same as those described above, and a different type of resin from the thermoplastic resin used in producing the masterbatch may be used, or a resin of the same type may be used.

[0060] The mixing ratio of the diluting resin to the masterbatch can be adjusted so that the carbon nanostructure is 1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin in the conductive resin composition in the end.

[0061] By manufacturing the conductive resin composition through the masterbatch and further manufacturing the molded body, the carbon nanostructure or its crushed product can be dispersed more uniformly in the molded body, and as a result, the desired functions and characteristics can be sufficiently imparted to the molded body.

[0062] Molded body

[0063] By molding the conductive resin composition of the present invention, a molded product having excellent conductivity and electromagnetic shielding properties can be obtained. That is, according to another aspect of the present invention, a molded product obtained from the conductive resin composition of the present invention is provided.

[0064] The molding method of the molded body is not particularly limited, and examples thereof include casting molding such as casting, injection molding using a mold, compression molding, extrusion molding using a T-die, etc., and melt molding such as blow molding.

[0065] In the manufacture of the molded body, it is possible to form only the resin composition of the present invention, or the resin composition of the present invention and other resin compositions can be used as raw materials. For example, the resin composition of the present invention can be molded into the whole of the molded body, or the resin composition of the present invention can be molded into only a part of the molded body.

[0066] The molded article formed by molding the conductive resin composition of the present invention by melt molding or the like has a form in which the carbon nanostructure or its crushed product is dispersed in the thermoplastic resin serving as a continuous phase, and thus has excellent conductivity and electromagnetic wave shielding properties. The molded article of the present invention may have, for example, 10 8 ~10 -1 The molded article of the present invention has excellent electromagnetic shielding properties. For example, when the carbon nanostructure is contained in an amount of 0.1 to 1.0 parts by mass relative to 100 parts by mass of the thermoplastic resin, the molded article has electromagnetic shielding properties up to the so-called millimeter wave band (100 MHz to 90 GHz band).

[0067] Therefore, the molded product of the present invention is particularly suitable for the housing of OA equipment and the housing of electrical and electronic equipment. As the applicable equipment, for example, there can be mentioned notebook personal computers, electronic notebooks, mobile phones, PDAs, etc., but as an application that most effectively exerts the electromagnetic wave shielding property that is a feature of the present invention, the housing of a notebook personal computer can be mentioned.

[0068] Example

[0069] The present invention will be further described in detail with the following examples and comparative examples. However, the protection scope of the present invention should not be limited to the following examples. In the following examples, the expressions "%" and "parts" are used, but they represent "mass %" and "mass parts" unless otherwise specified.

[0070] [Examples 1, 2, Comparative Examples 1, 2]

[0071] The filler and the polymer were melt-kneaded in a twin-screw extruder TEM-26SX (manufactured by Shibaura Machine Co., Ltd.) (barrel temperature 220°C (PP) or 260°C (PBT), screw speed 300 rpm, discharge volume 10 kg / hr) with the composition and ratio shown in the table to obtain a resin composition. The obtained resin composition was evaluated as follows. The results are shown in Table 1.

[0072] (Conductivity)

[0073] For the obtained resin composition, the PP base product was dried in an 80°C Gel aging thermostat and the PBT base product was dried in a 120°C Gel aging thermostat for 5 hours, and then the sample was placed on the mold and a pressure of 2MPa was applied by a hot press. The PP base product was preheated at 240°C and the PBT base product was preheated at 280°C for 5 minutes, and then a pressure of 20MPa was applied for 2 minutes. After that, the pressure was applied and cooled to room temperature, and the test piece was taken out to manufacture a flat plate with a thickness of 2mm×150mm×150mm. After that, the center of the plate was cut into a 60mm×60mm square to make a test piece. For the test piece, the surface resistivity was measured using an ultra-high resistance meter R8340A made by ADVANTEST CORPORATION according to the method of JISK6723.

[0074] (Electromagnetic wave shielding properties)

[0075] The 150 mm square plate obtained above was measured in the frequency range of 0.1 MHz to 1 GHz by the KEC method, and in the two frequency ranges of 26.5-40 GHz and 60-90 GHz by the Free Space method. In the Free Space method, a vector network analyzer was used to measure the S parameters (S21, S11) using two pairs of lens antennas arranged horizontally, and the shielding characteristics and absorption characteristics were calculated as follows as power references.

[0076] S21 = (Electromagnetic field strength of transmitted wave / Electromagnetic field strength of incident wave)

[0077] S11 = (Electromagnetic field strength of reflected wave / Electromagnetic field strength of incident wave)

[0078] Shielding characteristic (dB) = 10 × log 10 (S21 2 )

[0079] Reflectivity (%) = 100 × S11 2

[0080] Transmittance (%) = 100 × S21 2

[0081] Absorption (%) = 100 - reflectivity - transmittance

[0082] (Mechanical properties)

[0083] The obtained resin composition was dried for 5 hours in an 80°C Gel aging thermostat for PP and a 120°C Gel aging thermostat for PBT, and then injection molded into a JIS K7139 multi-purpose test piece A shape using an injection molding machine at a barrel temperature of 230°C for PP and 270°C for PBT, and then cut to produce a type 1 notched type A test piece specified in JIS K7111. The Charpy impact strength was measured at a measurement temperature of 23°C according to a method based on JIS K7111.

[0084] [Table 1]

[0085]

[0086] In addition, the following substances were used as each raw material in the table.

[0087] "Athlos100" ... Carbon nanostructure "ATHLOS (TM) 100 Carbon Nanostructure Pellets" (Cabot Corp). The Raman spectrum is shown in Figure 1 , Figure 2It should be noted that the Raman spectrum was measured by the following method.

[0088] "NC7000"... multi-walled carbon nanotube (manufactured by Nanocyl Corporation)

[0089] "PP"···Polypropylene resin (random polypropylene with an MFR of 5 to 10 g / 10 min at 230°C and 2.16 kg)

[0090] "PBT" ···polybutylene terephthalate (MFR 60 to 80 g / 10 min at 240°C and 2.16 kg)

[0091] In addition, MFR is measured as follows: the material is put into a melt indexer (orifice diameter: 2.1 mm), the above-mentioned load is applied, and the melt flow rate is measured after preheating for 5 minutes.

[0092] Comparing Example 1 with Comparative Example 1, it is shown that Example 1 maintains or even improves the impact resistance while having a lower surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance at 1 GHz to 70 GHz. In addition, the comparison between Example 2 and Comparative Example 2 also shows that Example 2 maintains or even improves the impact resistance while having a lower surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance at 1 GHz to 70 GHz.

[0093] [Examples 3, 4, Comparative Examples 3, 4]

[0094] The filler and the polymer were melt-kneaded in a twin-screw extruder TEM-26SX (manufactured by Shibaura Machine Co., Ltd.) (barrel temperature 220°C (PP) or 260°C (PBT), screw speed 300 rpm, discharge volume 10 kg / hr) with the composition and ratio shown in the table to obtain a resin composition. The obtained resin composition was evaluated as described above. The results are shown in Tables 2 and 3.

[0095] [Examples 5, 6, Comparative Examples 5, 6]

[0096] The resin compositions obtained in Example 1 and Comparative Example 1 were used as masterbatches, and the polymers were blended and diluted in such a manner that the proportion of fillers in the masterbatches finally became the proportions shown in Tables 2 and 3, and melt-kneaded in a twin-screw extruder TEM-26SX (manufactured by Shibaura Machine Co., Ltd.) (barrel temperature 220°C (PP) or 260°C (PBT), screw speed 300rpm, discharge volume 10kg / hr) to obtain resin compositions. The obtained resin compositions were evaluated as described above. The results are shown in Tables 2 and 3.

[0097] [Table 2]

[0098]

[0099] [Table 3]

[0100]

[0101] Comparing Example 3 with Comparative Example 3, it is shown that: Compared with Comparative Example 3, Example 3 maintains or even improves the impact resistance, while having a low surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance and electromagnetic wave absorption performance at 1 GHz to 70 GHz. Comparing Example 4 with Comparative Example 4, it is shown that: Compared with Comparative Example 4, Example 4 maintains or even improves the impact resistance, while having a low surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance and electromagnetic wave absorption performance at 1 GHz to 70 GHz. Comparing Example 5 with Comparative Example 5, it is shown that: Compared with Comparative Example 5, Example 5 maintains or even improves the impact resistance, while having a low surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance and electromagnetic wave absorption performance at 1 GHz to 70 GHz. Comparing Example 6 with Comparative Example 6, it is shown that: Compared with Comparative Example 6, Example 6 maintains or even improves the impact resistance, while having a low surface resistivity, excellent conductivity, and excellent electromagnetic wave shielding performance and electromagnetic wave absorption performance at 1 GHz to 70 GHz.

[0102] In addition, the results of Examples 3 and 4 and Examples 5 and 6 show that the same performance is achieved even when directly compounded or diluted using a masterbatch. In addition, it is shown that the electromagnetic wave shielding performance of Examples 3 to 6 is reduced compared to Example 1, but the electromagnetic wave absorption performance is improved, and therefore, it is particularly suitable for applications that require reduction of reflected noise.

[0103] (Raman spectroscopy measurement and results)

[0104] The samples (Athlos 100) were collected on a glass slide and subjected to Raman analysis (n=5).

[0105] Raman device: NRS5500 (Japan Spectroscope), excitation wavelength 633nm, 785nm

[0106] Grating: 600 lines

[0107] Exposure time: 100 seconds

[0108] Cumulative times: 2 times

[0109] Crystalline Si (520cm -1 ) to implement wavenumber correction.

[0110] Find G(1586cm -1 ) and D(1367cm -1) and calculated the G / D ratio (Table 4).

[0111] [Table 4]

[0112]

[0113] [Examples 7 to 9]

[0114] The filler and the polymer were melt-kneaded in a twin-screw extruder TEX-25αIII (manufactured by Nippon Steel Works, Ltd.) (barrel temperature 300° C., screw speed 200 rpm, discharge volume 15 kg / hr) with the composition and ratio shown in the table to obtain a resin composition. The obtained resin composition was evaluated as follows. The results are shown in Table 5.

[0115] (Conductivity)

[0116] The obtained resin composition was dried in a 140°C Gel oven for 2 hours and then prepared into a test piece of 100 mm×100 mm×2 mm using an injection molding machine at a cylinder temperature of 320 to 330°C. The surface resistivity of the test piece was measured in the same manner as above.

[0117] (Electromagnetic wave shielding properties)

[0118] The electromagnetic wave shielding properties of the 100 mm square plate obtained above were measured and calculated in the same manner as above.

[0119] (Mechanical properties)

[0120] A test piece of 10 mm×80 mm was cut from the 100 mm square plate obtained above in the material flow direction, and the Charpy impact strength was measured at a measurement temperature of 23° C. according to a method in accordance with JIS K7111.

[0121] [Table 5]

[0122]

[0123] In addition, the following substances were used as each raw material in the table.

[0124] "PPS"···Polyphenylene sulfide resin (melt viscosity 310°C, shear rate 1000sec ―1 10~20Pa·s)

[0125] It is shown that in Examples 7 to 9, while maintaining or even improving the impact resistance, the surface resistivity becomes low, the conductivity is excellent, and the electromagnetic wave shielding performance, absorption performance and mechanical strength at 1 GHz to 70 GHz are excellent.

Claims

1. A conductive resin composition, characterized in that It is made by melt-kneading thermoplastic resin and carbon nanostructure as necessary raw materials. The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin. The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

2. The conductive resin composition according to claim 1, wherein The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin to form a cross-linked structure.

3. The conductive resin composition according to claim 1, which is a masterbatch, The carbon nanostructure is contained in an amount of 1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

4. The conductive resin composition according to claim 1, wherein The thermoplastic resin includes at least one selected from the group consisting of polyamide-based resins, polyolefin-based resins, polyester-based resins, and polyphenylene-based resins. 5 . A molded body obtained by molding the conductive resin composition according to claim 1 . The molded article according to claim 5 , which is a conductive material or an electromagnetic wave shielding material.

7. A method for producing a conductive resin composition, characterized in that: The method comprises the steps of melt-kneading a thermoplastic resin and a carbon nanostructure. The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin. The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

8. A method for producing a conductive resin composition, characterized in that: The method comprises the steps of melt-kneading a thermoplastic resin and a carbon nanostructure in a ratio of 0.1 to 30 parts by mass of the carbon nanostructure to 100 parts by mass of the thermoplastic resin to produce a masterbatch. The method further comprises the step of melt-kneading the obtained masterbatch and a thermoplastic resin.

9. A method for producing a molded body, characterized in that: The method comprises the step of melt-molding a conductive resin composition containing a thermoplastic resin and a carbon nanostructure. The carbon nanostructure is formed by bonding carbon nanotubes and glass fibers with a bonding resin. The carbon nanostructure is contained in an amount of 0.1 to 30 parts by mass based on 100 parts by mass of the thermoplastic resin.

Images