阅读说明：本技术 树脂组合物 (Resin composition ) 是由 小松优规 鹭坂功一 于 2020-03-19 设计创作，主要内容包括：提供一种具有导电性、同时具有低吸水性的树脂组合物。一种树脂组合物,其特征在于,含有通过显微拉曼光谱法测得的拉曼光谱中波数1320cm～(-1)～1370cm～(-1)范围内的峰强度I-(D)相对于波数1560cm～(-1)～1600cm～(-1)范围内的峰强度I-(G)的相对强度比(I-(D)/I-(G))为0.6以下的碳纤维、以及热塑性树脂,表面电阻值在1×10～(2)Ω～1×10～(12)Ω范围内。(Provided is a resin composition having conductivity and low water absorption. A resin composition characterized by containing 1320cm wavelength in Raman spectrum measured by micro-Raman spectroscopy ‑1 ～1370cm ‑1 Peak intensity in the range I D Relative to wave number 1560cm ‑1 ～1600cm ‑1 Peak intensity in the range I G Relative intensity ratio (I) D /I G ) Carbon fiber having a surface resistance value of 1X 10 of 0.6 or less, and thermoplastic resin 2 Ω～1×10 12 In the range of omega.)

1. A resin composition characterized by containing the number of waves in Raman spectrum measured by micro-Raman spectroscopy1320cm^-1～1370cm^-1Peak intensity in the range I_DRelative to wave number 1560cm^-1～1600cm^-1Peak intensity in the range I_GRelative intensity ratio of (I)_D/I_GCarbon fiber having a surface resistance value of 1X 10 of 0.6 or less, and thermoplastic resin²Ω～1×10¹²In the range of omega.

2. The resin composition according to claim 1, wherein the carbon fiber has a relative strength ratio of I_D/I_GIs 0.12 or more.

3. The resin composition according to claim 1 or 2, wherein the aspect ratio of the carbon fiber is 10 or more.

4. The resin composition according to any one of claims 1 to 3, wherein the carbon fiber is contained in an amount of 1 to 50% by mass based on the entire resin composition.

5. The resin composition according to any one of claims 1 to 4, wherein the thermoplastic resin is at least one selected from cyclic olefin polymers and cyclic olefin copolymers.

6. The resin composition according to any one of claims 1 to 5, having a flexural modulus of elasticity of 3.5 to 8.0GPa as measured according to ISO 178.

Technical Field

The present invention relates to a resin composition suitable for forming a container or the like used in the electrical and electronic field where low water absorption and conductivity are required.

Background

For example, in a semiconductor manufacturing process, a semiconductor storage and transport container made of a resin composition is used for transporting or storing wafers and the like. As a performance required for a container for storing and transporting electronic devices such as semiconductor wafers, the container is required to have mechanical strength, and antistatic properties and low water absorption are required for protecting electronic devices such as semiconductors stored in the container. The container having antistatic properties suppresses adsorption of dust and dirt, and suppresses circuit breakage and the like of electronic components housed in the container. The container having low water absorption suppresses absorption and release of moisture in the container itself, and suppresses damage of the electronic component accommodated in the container due to moisture. With the increase in density of semiconductor integrated circuits, the antistatic property and low water absorption property of containers are required to be increased.

Containers for transporting or storing electronic parts are often formed using resin compositions. In order to form a container having antistatic properties, the antistatic properties of the container are improved by improving the conductivity of the matrix resin itself in the resin composition forming the container or by including a carbon filler having high conductivity in the resin composition.

For example, patent document 1 discloses a resin composition containing a cyclic olefin homopolymer, a fibrous conductive filler and an elastomer. The resin composition described in patent document 1 contains a cyclic olefin homopolymer to suppress outgas generated from the resin composition, and a fibrous conductive filler is used to impart mechanical strength and conductivity to improve antistatic properties. However, the resin composition described in patent document 1 does not improve low water absorption.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-231171

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin composition which is suitable for use in a container or the like in an electric and electronic field where electrical conductivity is required, has electrical conductivity, and has low water absorption.

Means for solving the problems

As a result of intensive studies in view of the above circumstances, the present inventors have found that the above problems can be solved by a resin composition containing a carbon fiber and a thermoplastic resin having a relative intensity ratio in a raman spectrum within a specific range, and have completed the present invention.

That is, the gist of the present invention is a resin composition containing 1320cm wavelength in Raman spectrum measured by micro-Raman spectroscopy^-1～1370cm^-1Peak intensity in the range I_DRelative to wave number 1560cm^-1～1600cm^-1Peak intensity in the range I_GRelative intensity ratio (I)_D/I_G) Carbon fiber having a surface resistance value of 1X 10 of 0.6 or less, and thermoplastic resin²Ω～1×10¹²In the range of omega.

Effects of the invention

According to the present invention, a resin composition which can be suitably used for forming a container or the like in the electric and electronic field requiring conductivity, has excellent conductivity, and has low water absorption can be provided.

Detailed Description

An example of the embodiment of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below, and can be carried out in any modification within the scope not departing from the gist of the present invention.

The resin composition according to the embodiment of the present invention contains 1320cm wavelength in Raman spectrum measured by micro-Raman spectroscopy^-1～1370cm^-1Peak intensity in the range I_DRelative to wave number 1560cm^-1～1600cm^-1Peak intensity in the range I_GRelative intensity ratio (I)_D/I_G) Carbon fiber having a surface resistance value of 1X 10 of 0.6 or less, and thermoplastic resin²Ω～1×10¹²In the range of omega.

Carbon fiber

The resin composition according to the embodiment of the present invention contains the relative strength ratio (I)_D/I_G) Carbon fibers of 0.6 or less, and a thermoplastic resin. The surface resistance value of the resin composition is 1 x 10²Ω～1×10¹²Since the carbon fiber is contained in the range of Ω, the molded article formed from the resin composition has not only conductivity but also reduced water absorption.

In Raman spectrum of carbon fiber measured by micro-Raman spectroscopy, wave number is 1560cm^-1～1600cm^-1Peaks appearing in the range are peaks which appear in common in the carbon material and are peaks derived from the graphite structure of the carbon fiber. Further, in the Raman spectrum of the carbon fiber, the wave number was 1320cm^-1～1370cm^-1Peaks appearing in the range are peaks originating from disorder, defects of the graphite structure. In Raman spectrum of carbon fiber, wave number is 1320cm^-1～1370cm^-1Peak intensity in the range I_DRelative to wave number 1560cm^-1～1600cm^-1Peak intensity in the range I_GRelative intensity ratio of_D/I_GSometimes referred to as the raman value (R-value), is related to the degree of graphitization of the carbon fiber. The larger the degree of graphitization, the smaller the raman value (R value). The greater the degree of graphitization, the higher the crystallinity, resulting in a crystal grain arrangement close to that of natural graphite. If the relative strength ratio I of the carbon fibers_D/I_GWhen the amount exceeds 0.6, crystallinity is low, graphitization degree is too small, water absorption is high, and water absorption cannot be reduced. Relative strength ratio of carbon fiber I_D/I_GIs 0.6 or less, preferably 0.5 or less, more preferably 0.4 or less, preferably 0.12 or more, more preferably 0.13 or more, further preferably 0.14 or more, further preferably 0.15 or more, and particularly preferably 0.16 or more. If the relative strength ratio I of the carbon fibers_D/I_GIf the value of (b) is too small, the degree of graphitization increases, and the carbon fiber becomes hard, so that the carbon fiber may be broken when the thermoplastic resin and the carbon fiber are kneaded.

In the carbon fiber, Raman light of the carbon fiber itselfThe spectrum, raman spectrum of carbon fiber in the resin composition, and raman spectrum of carbon fiber in a molded article such as a sheet formed from the resin composition can be measured by micro-raman spectroscopy. From these raman spectra, the relative intensity ratio of the peak intensity in a specific wavenumber range to the peak intensity in other specific wavenumber ranges can be determined. The Raman spectrum of the carbon fiber can be measured by the method of the examples described later, and can be measured by a micro-Raman spectroscopy method using a micro-laser Raman spectrometer (for example, DXR2 micro-laser Raman microscope). For example, when measuring the raman spectrum of the carbon fiber in the particle or molded article composed of the resin composition, the raman spectrum of the resin contained in the composition is measured in advance, the raman spectrum of the particle or molded article is measured, the raman spectrum of the carbon fiber is measured from the difference spectrum of the two raman spectra, and the relative intensity ratio I can be obtained from the raman spectrum_D/I_G。

Examples of the carbon fibers include pitch-based carbon fibers, Polyacrylonitrile (PAN) -based carbon fibers, rayon-based carbon fibers, and phenol-based carbon fibers. Pitch-based carbon fibers are preferably used as the carbon fibers, because the treatment for graphitization is relatively easy and a desired R value can be easily obtained.

The carbon fibers may also be graphitized. The graphitization treatment may be performed by various methods. For example, a method of heating at 1500 ℃ to 3500 ℃ in an inert atmosphere can be mentioned. Generally, if the temperature of the graphitization treatment is high, the graphitization degree is high. The temperature of the graphitization treatment is preferably in the range of 2000 to 3500 ℃ from the viewpoint that a desired R value can be easily obtained.

From the viewpoint of improving the handleability, the carbon fibers may be bundled with a sizing agent. The sizing agent is a sizing agent that disperses and adheres carbon fibers in a resin or is added to carbon fibers to bundle the fibers. Examples of the sizing agent include epoxy resins, urethane resins, and mixtures thereof. In order to reduce outgas generated by the organic material, the amount of the sizing agent added is preferably 3 mass% or less with respect to 100 mass% of the entire amount of the carbon fiber. When carbon fibers are bundled with a sizing agent, the fiber length of the bundled carbon fibers is preferably 3 to 6 mm.

The carbon fiber preferably has an average fiber diameter of 3 to 15 μm, more preferably 5 to 13 μm, and further preferably 7 to 12 μm. If the average fiber diameter of the carbon fibers is within the range of 3 to 15 μm, the carbon fibers are less likely to break when kneaded with a thermoplastic resin to obtain a resin composition, and a molded article having a desired surface resistance value can be formed. The average fiber diameter of the carbon fiber may be obtained by measuring the minor axis of, for example, 10 carbon fibers with an optical microscope and calculating the average fiber diameter of the carbon fibers from the average value. The average fiber diameter of the carbon fiber may be a known value such as a catalog value or a measured value.

The average fiber length of the carbon fiber is preferably in the range of 1 to 10mm, more preferably in the range of 2 to 9mm, further preferably in the range of 3 to 8mm, and particularly preferably in the range of 3 to 7 mm. If the average fiber length of the carbon fiber is in the range of 1 to 10mm, the following resin composition can be obtained: when the resin composition is kneaded with a thermoplastic resin, kneading is easy, and the carbon fibers are less likely to break, so that a molded article having a desired surface resistance value can be formed. The average fiber length of the carbon fibers may be a number average fiber length obtained by measuring the length of, for example, 10 carbon fibers with an optical microscope and calculating the average value thereof. The average fiber length of the carbon fiber may be a known value such as a catalog value or a measured value.

The aspect ratio of the carbon fibers in the resin composition is preferably 10 or more, more preferably 20 or more, preferably 3000 or less, and more preferably 2000 or less. When the aspect ratio of the carbon fibers is less than 10, the carbon fibers in the resin composition may not easily form a network with each other, and a molded article having sufficient conductivity may not be formed. The aspect ratio can be determined from the average fiber length and the average fiber diameter of the carbon fiber using an optical microscope (average fiber length/average fiber diameter).

The content of the carbon fiber in the resin composition is preferably in the range of 1 to 50% by mass, more preferably 3 to 45% by mass, further preferably 5 to 40% by mass, and particularly preferably 10 to 35% by mass, based on the whole amount (100% by mass) of the resin composition. When the content of the carbon fiber in the resin composition is in the range of 1 to 50% by mass, the resin composition has sufficient conductivity when used in the electric and electronic field, and a molded article formed from the resin composition has a desired surface resistance value, and is easily molded, for example, by injection molding.

Thermoplastic resin

Examples of the thermoplastic resin include polyether ether ketone resins, polyphenylene sulfide resins, polyether imide resins, polyether sulfone resins, polysulfone resins, polyarylate resins, modified polyphenylene ether resins, polyacetal resins, polycarbonate resins, polybutylene terephthalate resins, polyester resins such as polyethylene terephthalate resins, polyamide resins such as nylon 6 and nylon 66, styrene resins such as polystyrene resins and ABS resins, Cyclic Olefin Polymers (COP), Cyclic Olefin Copolymers (COC), polyolefin resins such as polypropylene and polyethylene, fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene-ethylene copolymers (ETFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (PFA), olefin elastomers such as ethylene-propylene rubber (EPR), styrene elastomers such as hydrogenated styrene thermoplastic elastomers (SEBS), styrene elastomers such as hydrogenated Styrene Elastomers (SEBS), polyether elastomers, polyether sulfone resins, polyether imide resins, and the like, Thermoplastic elastomers such as polyester elastomers, polyurethane elastomers, polyamide elastomers, silicone elastomers, and acrylic elastomers. Of these, at least 1 kind selected from the group consisting of polyether ether ketone resins, polyphenylene sulfide resins, polyether sulfone resins, polysulfone resins, polyarylate resins, modified polyphenylene ether resins, polyacetal resins, polycarbonate resins, polybutylene terephthalate resins, polyester resins such as polyethylene terephthalate resins, styrene resins such as polystyrene resins and ABS resins, Cyclic Olefin Polymers (COPs), Cyclic Olefin Copolymers (COCs), polyolefin resins such as polypropylene and polyethylene, fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene-ethylene copolymers (ETFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (PFA), olefin elastomers such as ethylene-propylene rubber (EPR), styrene elastomers such as hydrogenated styrene thermoplastic elastomers (SEBS), and polyester elastomers is preferable, and a Cyclic Olefin Polymer (COP) is more preferable, At least 1 kind selected from the group consisting of polyolefin resins such as Cyclic Olefin Copolymer (COC), polypropylene, and polyethylene, fluororesins such as polyvinylidene fluoride, polytetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and olefin elastomers such as ethylene-propylene rubber (EPR), and particularly preferably at least one kind selected from Cyclic Olefin Polymer (COP) and Cyclic Olefin Copolymer (COC).

The thermoplastic resin has low water absorption and can form a molded product with high dimensional accuracy, and is preferably at least one selected from a Cyclic Olefin Polymer (COP) and a Cyclic Olefin Copolymer (COC) having excellent moldability. The Cyclic Olefin Polymer (COP) is a ring-closed (co) polymer of a cyclic olefin having at least one olefinic double bond in a cyclic hydrocarbon structure such as cyclopentene, norbornene, tetracyclo [6,2,11,8,13,6] -4-dodecene, or a hydrogenated product thereof. The Cyclic Olefin Copolymer (COC) is an addition copolymer of a cyclic olefin and an α -olefin or a hydrogenated product thereof, and an addition polymer of a cyclic olefin and a cyclic diene and a hydrogenated product thereof. Examples of COP include cyclic olefin polymers as described in Japanese patent application laid-open Nos. H1-168724 and H1-168725. As the COC, there can be mentioned cyclic olefin copolymers as described in Japanese patent application laid-open Nos. 60-168708, 6-136057 and 7-258362. As at least one resin selected from the COP and the COC, for example, ZEONOR (registered trademark) manufactured by rayleigh corporation, ZEONEX (registered trademark), APEL (registered trademark) manufactured by mitsui chemical corporation, APO (registered trademark), and the like can be used.

The content of the thermoplastic resin in the resin composition is preferably in the range of 50 to 99 mass%, and may be in the range of 55 to 97 mass%, and may be in the range of 60 to 95 mass%, and may be in the range of 65 to 90 mass%, based on the whole amount (100 mass%) of the resin composition.

Other additives

The resin composition according to the embodiment of the present invention may contain any additives as necessary within a range not to impair the object. Examples of the additive include a relative intensity ratio I in Raman spectrum_D/I_GCarbon fiber, furnace black, acetylene of more than 0.6Various carbon blacks such as black, nanocarbons such as carbon nanotubes, graphene and fullerene, glass fibers, silica fibers, inorganic fibrous reinforcing materials such as silica-alumina fibers, potassium titanate fibers and aluminum borate fibers, organic fibrous reinforcing materials such as aramid fibers, polyimide fibers and fluororesin fibers, inorganic filler materials such as mica, glass beads, glass powder and glass spheres, release agents, antioxidants, heat stabilizers, light stabilizers, lubricants, ultraviolet absorbers, antifogging agents, antiblocking agents, slip agents, dispersants, antibacterial agents, colorants, fluorescent brighteners and the like. Except that the thermoplastic resin contained in the resin composition and the relative intensity ratio I in the Raman spectrum_D/I_GThe content of the additive other than the carbon fiber of 0.6% or less varies depending on the kind of the additive, and may be 10% by mass or less, 5% by mass or less, 3% by mass or less, and 1% by mass or less based on the entire amount of the resin composition.

Resin composition

The resin composition according to the embodiment of the present invention is obtained by using a kneading apparatus such as a hot roll, a kneader, a Banbury mixer, or a twin-screw kneading extruder, for example, and has a relative intensity ratio I in the Raman spectrum to a thermoplastic resin_D/I_GThe carbon fiber having a carbon content of 0.6 or less can be kneaded or melt-kneaded to produce a resin composition. The temperature at which the thermoplastic resin is melted in the production of the resin composition may be appropriately set according to the type of the resin, and may be set, for example, within a range of 200 to 400 ℃. The obtained resin composition can be made into a resin composition in the form of pellets by, for example, a pelletizer, as required.

Surface resistance value

The resin composition according to the embodiment of the present invention has a surface resistance value of 1X 10²Ω～1×10¹²In the range of omega. The surface resistance value of the resin composition may be measured by molding the resin composition into a sheet, for example, and measuring the surface resistance value of the sheet. The resin composition can be molded into a sheet of 100 mm. times.100 mm. times.2 mm in thickness by a 130-ton injection molding machine, for example. The resin composition according to the embodiment of the present invention has a surface resistance value of 1X 10²Ω～1×10¹²In the range of Ω, the conductivity is sufficient, and the water absorption is determined by the relative intensity ratio I of Raman spectrum_D/I_GThe carbon fiber content is reduced to 0.6 or less, and a molded product having conductivity and low water absorption can be formed from the resin composition. Further, the resin composition according to the embodiment of the present invention has a surface resistance value of 1X 10²Ω～1×10¹²In the range of Ω, the resin composition has sufficient conductivity and thus has high antistatic properties, and is suppressed in the adsorption of dust and dirt, and therefore can be used in the field of electric and electronic devices to form a transport container for semiconductors. The surface resistance of the resin composition is preferably 1X 10³Ω～1×10¹¹In the range of Ω, more preferably 1X 10⁴Ω～1×10¹⁰In the range of omega. If the surface resistance value of the resin composition is less than 1X 10²Ω is an excessively large discharge current, and the semiconductor element contained in the container formed using the resin composition according to the embodiment of the present invention may be broken. If the surface resistance value of the resin composition exceeds 1X 10¹²Ω is too high in surface resistance value, low in conductivity, and difficult to exhibit excellent antistatic properties. The surface resistance value was measured by the measurement method of the example described later.

As a measuring device of surface resistance value, the surface resistance value is less than 1 x 10⁴In case of Ω, the measurement can be performed using, for example, m Ω HiTESTER 3540 (manufactured by Nikkiso Co., Ltd.) using a clip-type lead 9287-10 (manufactured by Nikkiso Co., Ltd.).

As a measuring apparatus of the surface resistance value, the surface resistance value is 1 × 10⁴The value of Ω or more can be measured, for example, by using a UA probe (2-depth needle probe, probe pitch 20mm, probe tip diameter 2mm) using Hiresta UP (Dia Instruments Co., Ltd.).

Water absorption rate

The water absorption of a molded product using the resin composition according to the embodiment of the present invention is preferably less than 0.042%, more preferably 0.041% or less, and still more preferably 0.040% or less. If the molded product made of the resin composition according to the embodiment of the present invention has a water absorption of less than 0.042% and a low water absorption, for example, in a container made of the resin composition, absorption and release of moisture in the container itself are suppressed, and damage of electronic components housed in the container due to moisture can be suppressed, and the molded product can be suitably used in the field of electric and electronic devices. For example, a sheet of 100mm × 100mm × 2mm in thickness formed by using the resin composition according to the embodiment of the present invention in a 130-ton injection molding machine (e.g., manufactured by sumitomo heavy machinery industry co., ltd.) can be used as a molded product for measuring the water absorption rate. The water absorption of the molded article formed from the resin composition can be measured by the measurement method of the example described later. Specifically, it can be determined as follows: the resin composition according to the embodiment of the present invention was formed into a sheet sample of 100mm × 100mm × 2mm in thickness using a 130-ton injection molding machine, the sheet sample was immersed in water at 80 ℃ for 5 hours, then placed in water maintained at room temperature and left to stand for 5 minutes, the water on the surface of the sheet sample was wiped off, the moisture on the surface was blown off by an air gun, the weight was measured, and the ratio obtained by dividing the difference between the measured weight and the weight before immersion in water by the dry weight before immersion in water was used as the water absorption rate.

Modulus of elasticity in bending

The flexural modulus of a bending test piece using the resin composition according to the embodiment of the present invention measured according to ISO 178 is preferably within a range of 3.5 to 8.0GPa, more preferably within a range of 4.0 to 7.5GPa, and still more preferably within a range of 4.2 to 7.0 GPa. When the flexural modulus of the bending test piece using the resin composition according to the embodiment of the present invention is in the range of 3.5 to 8.0GPa, sufficient impact resistance can be obtained, and for example, a container made of the resin composition can suppress damage to electronic components and the like contained in the container. For the bending test piece for measuring the flexural modulus, for example, a bending test piece of 80mm × 10mm × 4mm in thickness formed by using the resin composition according to the embodiment of the present invention in a 130-ton injection molding machine (for example, manufactured by sumitomo heavy machinery industries co., ltd.) can be used.

Discharge current

The discharge current of a molded article using the resin composition according to the embodiment of the present invention is preferably less than 2.4A, more preferably 2.3A or less, still more preferably 2.2A or less, preferably 0.2A or more, and more preferably 0.5A or more. If the discharge current of the molded article using the resin composition according to the embodiment of the present invention is less than 2.4A, the discharge current suddenly becomes excessive and the semiconductor element contained in the container formed using the resin composition according to the embodiment of the present invention is not destroyed, and static electricity can be appropriately discharged, and adsorption of dust and dirt can be suppressed, and circuit damage of the electronic component contained in the container can be suppressed. The discharge current can be measured by the method of the example described later. For example, a sheet of 100mm × 100mm × 2mm in thickness formed by using the resin composition according to the embodiment of the present invention in a 130-ton injection molding machine (e.g., manufactured by sumitomo heavy machinery industries co., ltd.) can be used as a molded article for measuring a discharge current.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples within the scope not exceeding the gist thereof. The measurement method and evaluation method used in the present invention are as follows.

(A) Thermoplastic resin

Cyclic olefin polymer: trade name: ZEONOR (registered trademark), manufactured by Nippon ruing Co., Ltd

(B) Carbon fiber

(B-1) carbon fiber: carbon fibers (average fiber diameter 10 μm, average fiber length 6mm, tensile modulus 631GPa, catalog values).

(B-2) carbon fiber: carbon fibers (average fiber diameter 10 μm, average fiber length 6mm, tensile modulus 796GPa, catalog values).

(B-3) carbon fiber: carbon fibers (average fiber diameter 11 μm, average fiber length 6mm, tensile modulus 900GPa, catalog value).

(B-4) carbon fiber: carbon fibers (average fiber diameter 11 μm, average fiber length 6mm, tensile modulus 185GPa, catalog value).

(B-5) carbon fiber: carbon fibers (average fiber diameter 8 μm, average fiber length 6mm, tensile modulus 220GPa, catalog value).

Examples 1 to 4 and comparative examples 1 to 3

Pellets comprising the resin compositions of examples 1 to 4 and comparative examples 1 to 3 were produced by melt-kneading (a) a thermoplastic resin and (B) a carbon fiber at a cylinder temperature of 260 ℃ and a screw rotation speed of 100rpm using a twin-screw extruder (product name: PCM-45, L/D: 32 (L: screw length: D: screw diameter), manufactured by nippon corporation) according to the formulation shown in table 1, followed by cutting. In order to prevent the carbon fibers (B) from being excessively broken, the thermoplastic resin (a) fed from the root of the screw (L/D: 0) was melted by a kneading element having an L/D of 12, and then the carbon fibers (B) were fed from an L/D of 20.

In example 4 alone, (a) a thermoplastic resin and (B) a carbon fiber were fed from the screw root (L/D ═ 0).

The obtained pellets of the resin composition were dried in a dryer at 90 ℃ for 5 hours.

Using the dried pellets of the resin composition, a sheet sample of 100 mm. times.100 mm. times.thickness 2mm and a test piece for flexural modulus test (ISO standard, 80 mm. times.10 mm. times.thickness 4mm, flexural test piece) were produced using a 130-ton injection molding machine (product name: SE130D, manufactured by Sumitomo heavy machinery industries, Ltd.). The cylinder temperature of the 130-ton injection molding machine was set to 260 ℃ and the mold temperature was set to 60 ℃.

(1) Relative intensity ratio I in Raman spectrum of carbon fiber_D/I_G

The raman spectrum of the (B) carbon fiber contained in the sheet sample was measured by micro-raman spectroscopy.

Device name: DXR2 micro laser Raman microscope (manufactured by Termo Fisher SCIENTIFIC)

Laser wavelength: 532nm

Laser output level: 1.0mW

Grating: 900 strips/mm (lines/mm)

With respect to baseline, left end: 2100-1800 cm^-1And the right end: 1100-600 cm^-1The wavenumber position at which the peak intensity of the raman spectrum is the lowest in the range of (a) is taken as the end point of the baseline. From the Raman spectra of the sheet samples obtained from the resin compositions of the respective examples and comparative examples, the Raman spectra were obtainedOutput wave number of 1320cm^-1～1370cm^-1Peak intensity in the range I_DRelative to wave number 1560cm^-1～1600cm^-1Peak intensity in the range I_GRelative intensity ratio of_D/I_G. The results are shown in Table 1.

(2) Aspect ratio of carbon fibers

An image of a 30mm diameter by 0.05mm thick sheet obtained by hot-pressing pellets of the resin composition at 260 ℃ was analyzed by an optical microscope (product name: OPTIPHOT-2, Nicon Co., Ltd.), the major and minor axes of 10 carbon fibers were measured, the average of the major axes was defined as the average fiber length, and the average of the minor axes was defined as the average fiber diameter. The results are shown in Table 1.

(3) Surface resistance value

(3-1) surface resistance value of sample piece less than 1X 10⁴In case of Ω, m Ω HiTESTER 3540 (manufactured by Nikkiso Co., Ltd.) was used, and measurement was performed using a clip-type lead 9287-10 (manufactured by Nikkiso Co., Ltd.). On a sheet sample, toThe silver paste was applied to the left and right sides to form electrodes, and then clip leads were connected to the electrodes to measure the surface resistance. The applied voltage was measured as follows.

(3-2) surface resistance value of sample piece 1X 10⁴The probe length was measured using a UA probe (2-depth needle probe, probe pitch 20mm, probe tip diameter 2mm) using Hiresta UP (Dia Instruments Co., Ltd.). A conductive rubber (volume resistivity: 5. omega. cm) was attached to the tip of the contact pin of the UA probe with a conductive adhesive on the sheet sample, and the contact with the surface of the sheet sample was stabilized and measured. By mounting the conductive rubber on the UA probe, the variation in the contact area due to the roughness of the surface to be measured or the like is small, and therefore the surface resistance value can be measured accurately and stably. The results are shown in Table 1.

Surface resistance value: less than 1 x 10⁴Ω, voltage is applied: 1V

Surface resistance value: is 1 × 10⁴Omega is more than or equal to 1 multiplied by 10¹⁰Ω, voltage is applied: 10V

Surface resistance value: is 1 × 10¹⁰Omega is more than or equal to 1 multiplied by 10¹⁴Ω, voltage is applied: 100V

(4) Water absorption rate

The sheet samples were dried with a 90 ℃ dryer for 24 hours. After drying, the plate was placed in a desiccator and cooled to room temperature (25 ℃ C. + -5 ℃ C.), and the weight W of the plate sample was measured₁(g)。

Next, the sheet sample was immersed in deionized water at 80 ℃ for 5 hours, then cooled in deionized water maintained at room temperature (25 ℃. + -. 5 ℃) for 5 minutes, the sheet sample was taken out of the deionized water, the surface of the sheet sample was wiped off, moisture on the surface was blown off with an air gun, and then the weight W of the sheet sample was rapidly measured₂(g)。

The water absorption was determined as the ratio obtained by subtracting the weight W2 of the sample after the dipping from the weight W1 of the sample before the dipping in deionized water at 80 ℃ and dividing by the weight W1 of the sample before the dipping in deionized water at 80 ℃. Specifically, the water absorption was determined by the following formula (1). The results are shown in Table 1.

Water absorption (%) - (W)₁-W₂)/W₁×100(1)

(5) Modulus of elasticity in bending

The test pieces for flexural modulus test composed of the resin compositions of examples and comparative examples were measured in accordance with ISO 178 using a universal testing machine (product name: TISY-2600, manufactured by TISY Co., Ltd.). The results are shown in the table.

(6) Discharge current

An injection-molded sample (100 mm. times.100 mm. times.2 mm in thickness) was placed on a charging plate monitor (MODEL700A, manufactured by Hugle Electronics Inc.), and the sample on the charging plate was suspended from a ground state with an electrostatic capacity of 20pF after applying a voltage of 1000V. Then, a copper wire connected to the terminal ground is brought into contact with the sample to discharge, and a current having an amplitude of nanosecond level is generated and gradually attenuated. The highest current value at this time was taken as the discharge current. The discharge current was measured by a current probe (CT-1, manufactured by Tektronix Co., Ltd.) and a digital oscilloscope (product name: LC584A, manufactured by Leiko Co., Ltd.). In the measurement, 1 sample piece was repeated 10 times to obtain an average value of the discharge current. The results are shown in Table 1.

[ Table 1]

The resin compositions of examples 1 to 4 were used to form a sheet by an injection molding machine, and the sheet contained a relative intensity ratio I in a Raman spectrum_D/I_GCarbon fibers of 0.6 or less and a cyclic polyolefin polymer, and the sheet formed by an injection molding machine has a surface resistance of 1X 10²Ω～1×10¹²In the range of Ω, the water absorption rate is reduced to 0.040% or less, and the water-absorbing resin composition has low water absorption and excellent conductivity. The sheet formed using the resin compositions of examples 1 to 4 had a flexural modulus of elasticity in the range of 3.5 to 8.0GPa, and sufficient impact resistance was obtained. Further, the discharge current of the sheet formed using the resin compositions of examples 1 to 4 was in the range of 0.2A or more and less than 2.4A, and static electricity was appropriately discharged, and adsorption of dust and dirt was suppressed, and circuit damage and the like of the electronic components housed in the container were suppressed.

The sheet formed by the injection molding machine using the resin composition of comparative example 1 had a low surface resistance value, and the discharge current became too large. In comparative examples 2 and 3, the relative strength ratio ID/IG of the carbon fiber exceeded 0.6, although the surface resistance value was 1X 10²Ω～1×10¹²In the range of Ω, the water absorption rate could not be reduced, and the discharge current was higher than that of the sheets formed using the resin compositions of examples 1 to 4.

Industrial applicability

The resin composition of the present invention can be suitably used as a material for packaging materials, containers, and the like of electronic parts such as semiconductor light-emitting elements in technical fields requiring low water absorption and conductivity, for example, in the electric and electronic fields.