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  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
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  • C08K5/105—Esters; Ether-esters of monocarboxylic acids with phenols
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
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  • C08K5/10—Esters; Ether-esters
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/101—Esters; Ether-esters of monocarboxylic acids
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L21/00—Compositions of unspecified rubbers
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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  • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/12—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
  • C08J2327/16—Homopolymers or copolymers of vinylidene fluoride
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/011—Nanostructured additives

Definitions

• the present invention relates to an elastomer composition, a method for producing an elastomer composition, a crosslinked product, and a molded product, and more particularly to an elastomer composition capable of obtaining a molded product in which carbon nanotubes are more well dispersed in the elastomer.
• an elastomer composition obtained by blending a carbon material with an elastomer has been used as a material having excellent properties such as conductivity, thermal conductivity, and strength.
• carbon nanotubes hereinafter, may be abbreviated as "CNT"
• CNT carbon nanotubes
• CNTs have excellent characteristics one by one, they have a small outer diameter, so they are easy to bundle with Van der Waals force when used as bulk materials (easy to bundle). Therefore, when producing a molded product using an elastomer composition containing an elastomer and CNT, it is required to defibrate the bundle structure of CNT and to disperse CNT well in the matrix of the elastomer. .. In the present invention, it is shown that the carbon nanotube (CNT) contains a plurality of carbon nanotubes.
• Patent Document 1 a composition containing a polymer, CNT, and an organic solvent such as methyl ethyl ketone is kneaded in a subcritical or supercritical carbon dioxide atmosphere to obtain good CNT in the polymer matrix. It is disclosed that it can be dispersed in.
• An object of the present invention is to provide a new technique for obtaining a molded product in which carbon nanotubes are more well dispersed in an elastomer.
• the present inventors have conducted diligent studies to achieve the above object, and found that the distance of the Hansen solubility parameter between the elastomer and the elastomer, and the Hansen solubility parameter between the elastomer and the CNT are included.
• an elastomer composition containing the compound A having an aromatic ring, each of which has a distance satisfying a predetermined condition and a steam pressure of a predetermined value or less a molded body in which CNTs are well dispersed in the elastomer can be produced.
• the present invention was completed.
• the elastomer composition of the present invention is an elastomer composition containing an elastomer, carbon nanotubes, and compound A, wherein the compound A has a vapor pressure of 1.0 kPa or less at 25 ° C. and an aromatic ring.
• the distance R1 of the Hansen solubility parameter between the carbon nanotube and the compound A is 6.0 MPa 1/2 or less, and the distance R2 of the Hansen solubility parameter between the elastomer and the compound A is from R1. Is also big.
• the elastomer composition contains 0.1 part by mass or more and 60 parts by mass or less of the compound A per 100 parts by mass of the elastomer.
• the elastomer composition contains 0.1 part by mass or more and 10 parts by mass or less of the carbon nanotubes per 100 parts by mass of the elastomer.
• the carbon nanotubes preferably contain single-walled carbon nanotubes.
• the CNT When an elastomer composition containing a single-walled CNT is used as the CNT, a molded product having further excellent properties such as conductivity, thermal conductivity, and strength can be obtained.
• the compound A is preferably a phenyl ester compound. According to such a configuration, it is possible to obtain a molded product in which CNTs are more well dispersed in the elastomer.
• the elastomer composition can further contain a cross-linking agent.
• a cross-linking agent By using an elastomer composition containing a cross-linking agent, it is possible to obtain a molded product as a cross-linked body having excellent strength and the like when cross-linked.
• the method for producing an elastomer composition of the present invention is a method for producing the elastomer composition, wherein the step of mixing the carbon nanotube and the compound A to obtain a mixture and the mixture and the elastomer are combined. Includes a step of subjecting the composition to a dispersion treatment. According to such a configuration, an elastomer composition in which the CNT bundle structure is deflated well can be obtained, and by using the elastomer composition, a molded product in which CNTs are sufficiently well dispersed in the elastomer can be obtained. Obtainable.
• the crosslinked product of the present invention is obtained by cross-linking an elastomer composition containing the cross-linking agent. According to such a configuration, the obtained crosslinked product is excellent in properties such as conductivity, thermal conductivity, and strength because CNTs are well dispersed in the elastomer.
• the molded product of the present invention is formed by molding the crosslinked product. According to such a configuration, the obtained molded product is excellent in properties such as conductivity, thermal conductivity, and strength because CNTs are well dispersed in the elastomer.
• an elastomer composition capable of forming a molded body in which carbon nanotubes are more well dispersed in an elastomer, and a method for producing the same. Further, according to the present invention, it is possible to provide a crosslinked product and a molded product in which carbon nanotubes are well dispersed in an elastomer.
• the elastomer composition of the present invention can be used for producing the molded product of the present invention. Further, the elastomer composition of the present invention can be prepared, for example, by using the method for producing an elastomer composition of the present invention.
• the elastomer composition of the present invention contains an elastomer, CNT, compound A, and optionally contains a cross-linking agent, an additive, and the like.
• Compound A is a compound having a vapor pressure of 1.0 kPa or less at 25 ° C. and having an aromatic ring. Further, the distance R1 of the Hansen solubility parameter between CNT and compound A is 6.0 MPa 1/2 or less, and the distance R2 between the elastomer and the Hansen solubility parameter of compound A is larger than R1.
• the elastomer composition of the present invention by using the above-mentioned compound A, it is possible to obtain a molded product in which CNTs are more well dispersed in the elastomer.
• the value of the distance R1 of the Hansen solubility parameter between CNT and compound A is equal to or less than the above-mentioned predetermined value, and the compound A has an aromatic ring, so that the compounds A and CNT are used. Further, the compound A impregnates the inside of the bundle structure of CNT to promote the defibration of the bundle structure.
• the compound A can have a better affinity for CNT than the elastomer, and the presence of the elastomer is described above. It does not excessively inhibit the defibration of the bundle structure by the compound A. Therefore, it is considered that by using the above-mentioned elastomer composition, the bundle structure of CNTs can be sufficiently defibrated to obtain a molded product in which CNTs are well dispersed in the elastomer.
• the elastomer is not particularly limited, and for example, any rubber, resin, or a mixture thereof can be used.
• the rubber is not particularly limited, and is, for example, natural rubber; vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), tetrafluoroethylene-purple olovinyl ether rubber.
• Fluorine rubber such as (FFKM); butadiene rubber (BR), isoprene rubber (IR), styrene-butadiene rubber (SBR), hydride styrene-butadiene rubber (H-SBR), nitrile rubber (NBR), hydride nitrile rubber Diene rubber such as (H-NBR); silicone rubber; and the like.
• the resin is not particularly limited, and is, for example, a fluororesin such as polytetrafluoroethylene (PTFE); an acrylic resin such as polymethylmethacrylate (PMMA); polystyrene (PS); polycarbonate (PC); and the like. Can be mentioned.
• examples of the elastomer include fluororubbers such as vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), and tetrafluoroethylene-purple olovinyl ether rubber (FFKM); nitrile rubber (NBR). Hydrogenated nitrile rubber (H-NBR); fluororesin such as polytetrafluoroethylene; acrylic resin such as polymethylmethacrylate; polystyrene; polycarbonate; preferably, FKM, FEPM, H-NBR, PTFE, PMMA, PS and PC is more preferred.
• fluororubbers such as vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), and tetrafluoroethylene-purple olovinyl ether rubber (FFKM); nitrile rubber (NBR). Hydrogenated nitrile rubber (H-NBR); fluororesin such as polyte
• elastomer composition containing at least one of these elastomers it is possible to obtain a molded product in which CNTs are more well dispersed in the elastomer.
• these elastomers can be used individually by 1 type or by mixing 2 or more types.
• the CNT is composed of a plurality of carbon nanotubes.
• the type of CNT is not particularly limited, and includes single-walled carbon nanotubes and multi-walled carbon nanotubes.
• the CNT preferably contains carbon nanotubes having a relatively small number of layers from a single layer to five layers, and more preferably contains single-walled carbon nanotubes. At that time, it is more preferable that the CNT mainly contains carbon nanotubes from a single layer to five layers, and it is further preferable that the CNT mainly contains single-walled carbon nanotubes.
• CNTs having a relatively small number of layers improves the characteristics (for example, conductivity, thermal conductivity, strength, etc.) of the molded product even if the blending amount is small.
• the above-mentioned "mainly included” means that more than half of the total number of the plurality of carbon nanotubes is included.
• the average diameter of CNTs is preferably 1 nm or more, preferably 60 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less.
• the average diameter of CNTs is within the above range, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be sufficiently improved.
• the "mean diameter" of a CNT is calculated by measuring the diameter (outer diameter) of, for example, 20 CNTs on a transmission electron microscope (TEM) image and calculating the number average value. You can ask.
• the ratio (3 ⁇ / Av) of the value (3 ⁇ ) obtained by multiplying the standard deviation ( ⁇ : sample standard deviation) of the diameter to the average diameter (Av) by 3 is more than 0.20 and less than 0.80. It is preferable to use a CNT, more preferably a CNT having a 3 ⁇ / Av of more than 0.25, and even more preferably a CNT having a 3 ⁇ / Av of more than 0.50.
• CNTs having 3 ⁇ / Av of more than 0.20 and less than 0.80 the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be further improved.
• the average diameter (Av) and standard deviation ( ⁇ ) of CNTs may be adjusted by changing the manufacturing method and manufacturing conditions of CNTs, or by combining a plurality of types of CNTs obtained by different manufacturing methods. You may.
• the diameter measured as described above is plotted on the horizontal axis and the frequency is plotted on the vertical axis, and when approximated by Gaussian, a CNT having a normal distribution is usually used.
• the average length of CNTs is preferably 10 ⁇ m or more, more preferably 50 ⁇ m or more, further preferably 80 ⁇ m or more, preferably 600 ⁇ m or less, and 550 ⁇ m or less. It is more preferably 500 ⁇ m or less, and even more preferably 500 ⁇ m or less.
• the average length of CNTs is within the above range, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be sufficiently improved.
• the "mean length" of CNTs can be obtained by measuring the lengths of, for example, 20 CNTs on a scanning electron microscope (SEM) image and calculating the number average value. can.
• CNTs usually have an aspect ratio of more than 10.
• the diameter and length of 20 randomly selected CNTs were measured using a scanning electron microscope or a transmission electron microscope, and the ratio of diameter to length (length / diameter) was measured. It can be obtained by calculating the average value.
• the CNT has a BET specific surface area preferably 600 m 2 / g or more, more preferably 800 m 2 / g or more, preferably 2000 m 2 / g or less, and 1800 m 2 / g or less. It is more preferably present, and further preferably 1600 m 2 / g or less.
• the BET specific surface area of CNT is 600 m 2 / g or more, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be sufficiently enhanced with a small blending amount.
• the BET specific surface area of CNT is 2000 m 2 / g or less, the bundle structure of CNT can be defibrated satisfactorily.
• the "BET specific surface area” refers to the nitrogen adsorption specific surface area measured by the BET method.
• the CNT shows an upwardly convex shape in the t-plot obtained from the adsorption isotherm.
• the "t-plot" can be obtained by converting the relative pressure into the average thickness t (nm) of the nitrogen gas adsorption layer in the adsorption isotherm of CNT measured by the nitrogen gas adsorption method. That is, the above conversion is performed by obtaining the average thickness t of the nitrogen gas adsorption layer corresponding to the relative pressure from a known standard isotherm obtained by plotting the average thickness t of the nitrogen gas adsorption layer with respect to the relative pressure P / P0.
• a t-plot of CNT t-plot method by de Boer et al.
• the CNTs obtained from the adsorption isotherms whose t-plot shows an upwardly convex shape are preferably CNTs that have not been subjected to opening treatment.
• the growth of the nitrogen gas adsorption layer is classified into the following processes (1) to (3). Then, the slope of the t-plot changes due to the following processes (1) to (3).
• the plot In the t-plot showing an upwardly convex shape, the plot is located on a straight line passing through the origin in the region where the average thickness t of the nitrogen gas adsorption layer is small, whereas when t is large, the plot is the straight line. The position is shifted downward from.
• the CNT having such a t-plot shape has a large ratio of the internal specific surface area to the total specific surface area of the CNT, indicating that a large number of openings are formed in the CNT.
• the bending point of the CNT t-plot is preferably in the range of 0.2 ⁇ t (nm) ⁇ 1.5, and preferably in the range of 0.45 ⁇ t (nm) ⁇ 1.5. Is more preferable, and it is further preferable that the range is 0.55 ⁇ t (nm) ⁇ 1.0. As long as the bending point of the CNT t-plot is within such a range, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be enhanced with a small blending amount.
• the "position of the bending point" is the intersection of the approximate straight line A of the process of (1) described above and the approximate straight line B of the process of (3) described above.
• the CNT preferably has a ratio (S2 / S1) of the internal specific surface area S2 to the total specific surface area S1 obtained from the t-plot of 0.05 or more and 0.30 or less.
• S2 / S1 of CNT is within such a range, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be enhanced with a small blending amount.
• the total specific surface area S1 and the internal specific surface area S2 of the CNT can be obtained from the t-plot.
• the total specific surface area S1 can be obtained from the slope of the approximate straight line in the process (1), and the external specific surface area S3 can be obtained from the slope of the approximate straight line in the process (3). Then, the internal specific surface area S2 can be calculated by subtracting the external specific surface area S3 from the total specific surface area S1.
• the measurement of the adsorption isotherm of CNT, the creation of the t-plot, and the calculation of the total specific surface area S1 and the internal specific surface area S2 based on the analysis of the t-plot can be performed by, for example, "BELSORP (BELSORP), which is a commercially available measuring device. It can be performed using "registered trademark) -mini” (manufactured by Nippon Bell Co., Ltd.).
• the CNT has a peak of RadialBreathing Mode (RBM) when evaluated using Raman spectroscopy. It should be noted that RBM does not exist in the Raman spectrum of three or more multi-walled CNTs.
• the ratio (G / D ratio) of the G band peak intensity to the D band peak intensity in the Raman spectrum is preferably 0.5 or more and 5.0 or less, and can be 1.0 or more. It may be 4.0 or less.
• the G / D ratio is 0.5 or more and 5.0 or less, the characteristics of the molded product (for example, conductivity, thermal conductivity, strength, etc.) can be further improved.
• the CNT can be produced by using a known CNT synthesis method such as an arc discharge method, a laser ablation method, and a chemical vapor deposition method (CVD method) without particular limitation.
• CNTs are used, for example, when a raw material compound and a carrier gas are supplied onto a substrate having a catalyst layer for CNT production on the surface, and CNTs are synthesized by a chemical vapor phase growth method (CVD method).
• CVD method chemical vapor phase growth method
• the CNT obtained by the super growth method may be referred to as "SGCNT".
• the CNT produced by the super growth method may be composed of only SGCNTs, or may contain other carbon nanostructures such as non-cylindrical carbon nanostructures in addition to SGCNTs. good.
• Compound A is a compound having an aromatic ring having a vapor pressure at 25 ° C. of 1.0 kPa or less, and is not particularly limited as long as it satisfies the condition regarding the distance of the Hansen solubility parameter described later, and is any organic compound. Can be used.
• the aromatic ring of compound A has an excellent affinity for CNTs, which promotes the defibration of the bulk structure of CNTs, and in the obtained molded product, CNTs can be more well dispersed in the elastomer. ..
• the aromatic ring of compound A is not particularly limited, and specific examples thereof include a benzene ring and a naphthalene ring.
• the compound A may have one kind of aromatic ring or may have two or more kinds of aromatic rings.
• a benzene ring is preferable from the viewpoint of better dispersing CNTs in the elastomer.
• a compound having an ester group and an aromatic ring is preferable from the viewpoint of better dispersing CNT in the elastomer in the molded product.
• the compound having an ester group and an aromatic ring is preferably a phenyl ester compound, for example, a benzoic acid ester compound such as methyl benzoate, benzyl benzoate, or phenyl benzoate, or 3-phenylpropion such as methyl 3-phenylpropionate.
• Alkyl acid can be mentioned.
• the compound A can be used alone or in combination of two or more.
• the vapor pressure of compound A at 25 ° C. is 1.0 kPa or less, and more preferably 0.1 kPa or less. If the vapor pressure of compound A exceeds 1.0 kPa, it is presumed that the fluidity of compound A cannot be sufficiently secured and it becomes difficult to impregnate the inside of the bundle structure of CNT, but it is obtained from the elastomer composition. In the molded product, CNTs cannot be well dispersed in the elastomer.
• the lower limit of the vapor pressure of compound A is not particularly limited, but is, for example, 10-5 kPa or more.
• Compound A preferably has a boiling point of 120 ° C. or higher, more preferably 150 ° C. or higher.
• the boiling point of the compound A is 120 ° C. or higher, the compound A is not excessively vaporized when the elastomer composition and the molded product are obtained, and the CNT is satisfactorily contained in the elastomer in the molded product obtained from the elastomer composition. Can be dispersed.
• the upper limit of the boiling point of compound A is not particularly limited, but is, for example, 400 ° C. or lower.
• Compound A preferably has a molecular weight of 100 or more, more preferably 120 or more, preferably 500 or less, more preferably 400 or less, and even more preferably 300 or less. If the molecular weight of the compound A is within the above range, it is presumed that the compound A can be easily impregnated into the bundle structure of the CNT. It can be dispersed well.
• the compound A and the above-mentioned CNT need to have a Hansen solubility parameter distance R1 (unit: MPa 1/2 ) or less of 6.0 MPa 1/2 or less, and 5.0 MPa 1/2 . It is preferably less than or equal to, more preferably 4.5 MPa 1/2 or less, further preferably 4.0 MPa 1/2 or less, and particularly preferably 3.5 MPa 1/2 or less. It is presumed that when R1 exceeds 6.0 MPa 1/2 , the affinity of compound A with CNT decreases and it becomes difficult for compound A to impregnate the inside of the bulk structure of CNT, but it is obtained from the elastomer composition. CNTs cannot be well dispersed in the elastomer in the molded article.
• the lower limit of the value of R1 is not particularly limited, but is preferably 0.5 MPa 1/2 or more, and more preferably 1.0 MPa 1/2 or more.
• the "distance R1 (MPa 1/2 ) of the Hansen solubility parameter between the carbon nanotube and the compound A" can be calculated by using the following formula (1).
• R1 ⁇ 4 ⁇ ( ⁇ d3- ⁇ d2) 2 + ( ⁇ p3- ⁇ p2) 2 + ( ⁇ h3- ⁇ h2) 2 ⁇ 1/2 ...
• ⁇ d2 Dispersion term of compound A
• ⁇ d3 Dispersion term of carbon nanotube
• ⁇ p2 Polarity term of compound A
• ⁇ p3 Polarity term of carbon nanotube
• ⁇ h2 Hydrogen bond term of compound A ⁇ h3: Hydrogen bond term of carbon nanotube
• the distance R2 (unit: MPa 1/2 ) of the Hansen solubility parameter of the compound A and the above-mentioned elastomer needs to be larger than R1 as described above.
• R2 is R1 or less, it is presumed that compound A is less likely to be impregnated into the bulk structure of CNT due to the high affinity with the elastomer, but in the molded product obtained from the elastomer composition. , CNTs cannot be well dispersed in the elastomer.
• R2 is preferably 4.0 MPa 1/2 or more, more preferably 4.5 MPa 1/2 or more, preferably 16.0 MPa 1/2 or less, and 9.0 MPa. It is more preferably 1/2 or less.
• R2 is within the above range, CNTs can be more well dispersed in the elastomer in the molded product obtained from the elastomer composition.
• the "distance R2 (MPa 1/2 ) of the Hansen solubility parameter between the elastomer and the compound A" can be calculated using the following formula (2).
• R2 ⁇ 4 ⁇ ( ⁇ d1- ⁇ d2) 2 + ( ⁇ p1- ⁇ p2) 2 + ( ⁇ h1- ⁇ h2) 2 ⁇ 1/2 ...
• ⁇ d1 Dispersion term of elastomer
• ⁇ d2 Dispersion term of compound A
• ⁇ p1 Polarity term of elastomer
• ⁇ p2 Polarity term of compound A
• ⁇ h1 Hydrogen bond term of elastomer
• ⁇ h2 Hydrogen bond term of compound A
• Hansen solubility parameter The definition and calculation method of the Hansen solubility parameter are described in the following documents. Charles M. Hansen, "Hansen Solubility Parameters: A Users Handbook", CRC Press, 2007.
• the Hansen solubility parameter can be easily estimated from the chemical structure by using computer software (Hansen Solubility Parameter in Practice (HSPiP)).
• HSPiP version 3 may be used, the value may be used for the compound registered in the database, and the estimated value may be used for the compound not registered.
• the elastomer composition preferably contains 0.1 part by mass or more of the above-mentioned compound A, more preferably 5 parts by mass or more, further preferably 10 parts by mass or more, and 20 parts by mass per 100 parts by mass of the elastomer. The above may be included. Further, the elastomer composition preferably contains 60 parts by mass or less of the above-mentioned compound A, more preferably 50 parts by mass or less, and further preferably 40 parts by mass or less per 100 parts by mass of the elastomer. When the content of compound A in the elastomer composition is within the above range, CNTs can be more well dispersed in the elastomer in the molded product obtained from the elastomer composition.
• the elastomer composition preferably contains 0.1 part by mass or more of the above-mentioned CNTs, more preferably 1 part by mass or more, further preferably 2 parts by mass or more, and 3 parts by mass or more per 100 parts by mass of the elastomer. It may be included. Further, the elastomer composition preferably contains 10 parts by mass or less of the above-mentioned CNTs, more preferably 8 parts by mass or less, further preferably 7 parts by mass or less, and 6 parts by mass or less per 100 parts by mass of the elastomer. It may be included. When the content of CNTs in the elastomer composition is within the above range, CNTs can be more well dispersed in the elastomer in the molded product obtained from the elastomer composition.
• the cross-linking agent that can be arbitrarily contained in the elastomer composition of the present invention is not particularly limited, but a known cross-linking agent capable of cross-linking the elastomer in the above-mentioned elastomer composition can be used.
• a cross-linking agent include a sulfur-based cross-linking agent, a peroxide-based cross-linking agent, a bisphenol-based cross-linking agent, and a diamine-based cross-linking agent.
• the cross-linking agent may be used alone or in combination of two or more.
• the content of the cross-linking agent in the elastomer composition is not particularly limited, and can be an amount normally used in a known elastomer composition.
• the additives are not particularly limited, and are not particularly limited, and are dispersants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, pigments, colorants, foaming agents, antistatic agents, flame retardants, lubricants, and softeners. , Adhesives, plasticizers, mold release agents, deodorants, fragrances and the like. More specific additives include, for example, carbon black, silica, talc, barium sulfate, calcium carbonate, clay, magnesium oxide, calcium hydroxide and the like. The additive may be used alone or in combination of two or more.
• the content of the additive in the elastomer composition is not particularly limited, and can be an amount normally used in a known elastomer composition. For example, the content of the additive in the elastomer composition can be 5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the elastomer.
• the above-mentioned elastomer composition of the present invention can be prepared, for example, by using the method for producing an elastomer composition of the present invention.
• the method for producing an elastomer of the present invention comprises a step of mixing CNT and compound A to obtain a mixture containing CNT and compound A (mixing step), and a composition in which the mixture obtained in the mixing step and the elastomer are combined. Includes a step of performing a dispersion treatment (dispersion step).
• the method for producing the elastomer composition of the present invention may include steps other than the above-mentioned mixing step and dispersion step. For example, after the dispersion step is carried out, the cross-linking agent, the additive and the like may be added separately to further perform the dispersion treatment.
• the bundle structure of CNT is defibrated.
• the CNT can be well dispersed in the elastomer.
• the CNT and compound A are mixed in the mixing step before the dispersion step, the CNT is impregnated with the compound A, and the bundle structure of the CNT is easily defibrated. Therefore, during the dispersion treatment in the dispersion step, the CNT bundle structure can be defibrated satisfactorily and the CNTs can be dispersed more satisfactorily in the elastomer.
• ⁇ Mixing process> CNT and compound A are mixed to obtain a mixture containing CNT and compound A.
• a cross-linking agent and / or an additive may be optionally mixed with CNT and compound A and contained in the mixture, depending on the use of the elastomer composition and the molded product. Further, the mixing of CNT and compound A in the mixing step is usually carried out in the absence of an elastomer.
• the mixing of CNT and compound A is not particularly limited, and for example, immersion of CNT in compound A, impregnation of compound A into CNT, application of compound A to CNT, and compound to CNT. It can be carried out by using any mixing method such as spraying A. Above all, from the viewpoint of enabling better dispersion of CNTs in the dispersion step, it is preferable to impregnate the CNTs with the compound A to mix the CNTs with the compound A.
• the time for impregnating the CNTs with the compound A in the mixing step can be any time, but from the viewpoint of allowing the CNTs to be dispersed more satisfactorily in the dispersion step, at least 1 hour is preferable. 10 hours is more preferred.
• the temperature at which the CNT is impregnated with the compound A is not particularly limited, and may be, for example, a temperature equal to or higher than the freezing point of the compound A and lower than the boiling point.
• the impregnation of compound A into CNTs is not particularly limited, but is usually carried out under normal pressure (1 atm).
• a dispersion treatment is performed on the composition obtained by mixing the CNT and the compound A in the mixing step and the elastomer.
• a cross-linking agent and / or an additive may be optionally contained in the composition depending on the use of the elastomer composition and the molded product.
• the dispersion treatment is not particularly limited as long as the CNTs can be dispersed in the elastomer, and a known dispersion treatment can be used.
• a dispersion treatment include a dispersion treatment by shear stress, a dispersion treatment by collision energy, and a dispersion treatment in which a cavitation effect can be obtained. According to such a dispersion treatment, it is not necessary to carry out the dispersion treatment in the conventional supercritical carbon dioxide atmosphere, and the dispersion treatment can be carried out relatively easily.
• Examples of the apparatus that can be used for the dispersion treatment by shear stress include a two-roll mill and a three-roll mill.
• Examples of the device that can be used for the dispersion processing by the collision energy include a bead mill, a rotor / stator type disperser, and the like.
• Examples of the device that can be used for the dispersion processing that can obtain the cavitation effect include a jet mill and an ultrasonic disperser.
• the conditions for the above-mentioned dispersion processing are not particularly limited, and can be appropriately set within the range of the usual dispersion conditions in the above-mentioned apparatus, for example.
• Crosslinked product of the present invention is obtained by cross-linking an elastomer composition containing the above-mentioned cross-linking agent.
• the molded product of the present invention is formed by molding the above-mentioned elastomer composition of the present invention, particularly the above-mentioned crosslinked product.
• the molded product of the present invention is not particularly limited, and is, for example, a belt, a hose, a gasket, a packing, and an oil seal.
• the molded product of the present invention obtained from the above-mentioned elastomer composition of the present invention is excellent in properties such as conductivity, thermal conductivity, and strength because CNTs are well dispersed in the elastomer.
• the molding of the elastomer composition is not particularly limited, and can be performed by using any molding method such as injection molding, extrusion molding, press molding, and roll molding.
• Example 2 A rubber sheet was prepared in the same manner as in Example 1 except that the amount of methyl 3-phenylpropionate was 72.0 g (24 parts by mass per 100 parts by mass of the above-mentioned FKM), and the surface resistivity was measured. The results are shown in Table 1.
• Example 3 A rubber sheet was prepared in the same manner as in Example 1 except that the amount of methyl 3-phenylpropionate was 120.0 g (40 parts by mass per 100 parts by mass of the above-mentioned FKM), and the surface resistivity was measured. The results are shown in Table 1.
• a rubber sheet was prepared in the same manner as in Example 1 except that 72.0 g (24 parts by mass per 100 parts by mass of FKM) was used at kPa, boiling point: 200 ° C., molecular weight: 136), and the surface resistance was measured. The results are shown in Table 1. The distance R1 of the Hansen solubility parameter between the single layer CNT and methyl benzoate was 2.2 MPa 1/2 , and the distance R2 of the Hansen solubility parameter between FKM and methyl benzoate was 5.6 MPa 1/2 .
• a rubber sheet was prepared in the same manner as in Example 1 except that 72.0 g (24 parts by mass per 100 parts by mass of FKM) was used at kPa, boiling point: 324 ° C., molecular weight: 212), and the surface resistance was measured. The results are shown in Table 1.
• the distance R1 of the Hansen solubility parameter between the single-layer CNT and benzyl benzoate was 0.5 MPa 1/2
• the distance R2 of the Hansen solubility parameter between FKM and benzyl benzoate was 7.2 MPa 1/2 .
• Example 6 Wrap the rubber sheet produced in Example 2 around an open roll, and use 3 parts by mass of zinc oxide (zinc oxide 2 types) as a cross-linking agent and triallyl isocyanurate (manufactured by Mitsubishi Chemical Co., Ltd., "TAIC M-60") as a co-crosslinking agent. ) Add 5 parts by mass and 2 parts by mass of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (manufactured by Nichiyu Co., Ltd., "Perhexa 25B40") as a cross-linking agent and knead. The obtained rubber composition was subjected to primary vulcanization (160 ° C. ⁇ 15 minutes) and secondary vulcanization (232 ° C. ⁇ 2 hours) to obtain a sheet-shaped molded product.
• zinc oxide zinc oxide 2 types
• triallyl isocyanurate manufactured by Mitsubishi Chemical Co., Ltd., "TAIC M-60"
• TAIC M-60
• the distance R1 of the Hansen solubility parameter between the single-walled CNT and methyl salicylate was 7.0 MPa 1/2
• the distance R2 of the Hansen solubility parameter between FKM and methyl salicylate was 8.2 MPa 1/2 .
• the distance R1 of the Hansen solubility parameter between the single-walled CNT and toluene was 3.4 MPa 1/2
• the distance R2 of the Hansen solubility parameter between FKM and toluene was 7.2 MPa 1/2 .
• the distance R1 of the Hansen solubility parameter between the single-walled CNT and cyclohexanone was 3.4 MPa 1/2
• the distance R2 of the Hansen solubility parameter between FKM and cyclohexanone was 5.5 MPa 1/2 .
• the distance R1 of the Hansen solubility parameter between the single-walled CNT and the methyl ethyl ketone was 7.0 MPa 1/2
• the distance R2 of the Hansen solubility parameter between the FKM and the methyl ethyl ketone was 1.2 MPa 1/2 .
• an elastomer composition capable of forming a molded body in which carbon nanotubes are well dispersed in an elastomer, a method for producing the same, and the like. According to the present invention, it is possible to provide a molded product in which carbon nanotubes are well dispersed in an elastomer.

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• 2021
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