Method for adsorbing fluorine-containing low molecular weight compounds

Abstract

To provide a method for adsorbing a fluorine-containing low molecular weight compound by using an adsorbent containing a polymer.SOLUTION: A method for adsorbing a fluorine-containing low molecular weight compound includes adsorbing a fluorine-containing low molecular weight compound to an adsorbent by bringing the adsorbent and the fluorine-containing low molecular weight compound into contact with each other. The adsorbent comprises at least one kind of polymer selected from a group consisting of rubber and a cured material of the rubber. In the method for adsorbing a fluorine-containing low molecular weight compound, the rubber comprises at least one kind of rubber selected from a group consisting of hydrocarbon system rubber, silicone rubber, and fluorine-containing rubber.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a method for adsorbing fluorine-containing low molecular weight compounds.

Background Art

[0002] As a method for adsorbing low molecular weight compounds, a method of bringing a low molecular weight compound into contact with an adsorbent to adsorb the low molecular weight compound onto the adsorbent is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 discloses a method for adsorbing a combustible gas onto an adsorbent containing a polymer, but does not disclose a method for adsorbing low molecular weight compounds other than combustible gases.

[0005] An object of the present disclosure is to provide a method for adsorbing a fluorine-containing low molecular weight compound using an adsorbent containing a polymer.

Means for Solving the Problems

[0006] The present disclosure includes the following aspects. [1] A method for adsorbing a fluorine-containing low molecular weight compound, comprising: bringing an adsorbent into contact with the fluorine-containing low molecular weight compound to adsorb the fluorine-containing low molecular weight compound onto the adsorbent, wherein the adsorbent contains at least one polymer selected from the group consisting of rubber and a cured product of the rubber, the rubber contains at least one rubber selected from the group consisting of hydrocarbon rubber, silicone rubber, and fluororubber. Adsorption method of fluorine-containing low molecular weight compounds. [2] The adsorption method of the fluorine-containing low molecular weight compound according to [1] above, wherein the adsorbent is particulate. [3] The adsorption method of the fluorine-containing low molecular weight compound according to [2] above, wherein the particle diameter of the adsorbent is less than 1.0 mm. [4] The adsorption method of the fluorine-containing low molecular weight compound according to any one of [1] to [3] above, wherein the hydrocarbon rubber is a diene rubber. [5] The hydrocarbon rubber is -CH 2 -C(-X 1 )=CH-CH 2 -: [In the formula: X 1 is a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms] The adsorption method of the fluorine-containing low molecular weight compound according to any one of [1] to [4] above, which contains a monomer unit represented by [6] The hydrocarbon rubber further -CH 2 CHX 2 -: [In the formula: X 2 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyano group, or a phenyl group. The adsorption method of the fluorine-containing low molecular weight compound according to [5] above, which contains a monomer unit represented by.] [7] The silicone rubber is R a SiO (4-a) / 2 : [In the formula: R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different from each other, a is 1.9 to 2.1.] The adsorption method of the fluorine-containing low molecular weight compound according to any one of [1] to [6] above, which contains a compound represented by the average composition formula of [8] R is an alkyl group, a cycloalkyl group, an alkenyl group, a vinyl group, an aryl group, or a group in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom or a cyano group. The method for adsorbing the fluorine-containing low molecular weight compound according to the above [7]. [9] The fluororubber has the following formula: CF 2 =CR 1 R 2 : [Wherein: R 1 is a hydrogen atom or a fluorine atom, and R 2 is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a fluorine atom. ] The method for adsorbing the fluorine-containing low molecular weight compound according to any one of the above [1] to [8], which contains a monomer unit derived from a fluorine-containing monomer represented by the formula.

[10] The fluorine-containing low molecular weight compound has a saturated vapor pressure in the temperature range of -150°C to 150°C and has one or more fluorine atoms. The method for adsorbing the fluorine-containing low molecular weight compound according to any one of the above [1] to [9].

[11] The fluorine-containing low molecular weight compound is represented by formula (1) or (2): C p F q Y r : (1) [Wherein p, q, and r are integers of 1 or more, and q + r = 2p + 2, and Y each independently represents one kind of atom selected from the group consisting of a halogen atom and a hydrogen atom. ] C n F m Z l : (2) [Wherein n, m, and l are integers of 1 or more, and m + l = 2n, n ≧ 2, and Z each independently represents one kind of atom selected from the group consisting of a halogen atom and a hydrogen atom. ] The method for adsorbing a fluorine-containing low-molecular compound according to any one of [1] to

[10] above, which is at least one fluorocarbon represented by

[12] The method for adsorbing a fluorine-containing low-molecular compound according to

[11] above, wherein p is 1 or 2 and q is 2 or more.

[13] The method for adsorbing a fluorine-containing low-molecular compound according to

[11] or

[12] above, wherein the halogen atom is a chlorine atom.

[14] The method for adsorbing a fluorine-containing low-molecular compound according to any one of

[11] to

[13] above, wherein n is 2 or 3 and m is 2 or more.

[15] The method for adsorbing a fluorine-containing low-molecular compound according to any one of

[11] to

[14] above, wherein Z is a hydrogen atom.

[16] The method for adsorbing a fluorine-containing low-molecular compound according to any one of [1] to

[15] above, wherein the adsorption amount of the fluorine-containing low-molecular compound to the adsorbent is controlled based on the difference between the polarization rate of the adsorbent and the polarization rate of the fluorine-containing low-molecular compound.

[17] Adsorbing a fluorine-containing low-molecular compound by the method according to any one of [1] to

[16] above, and Placing the adsorbent adsorbed with the fluorine-containing low-molecular compound under reduced pressure conditions, and desorbing the fluorine-containing low-molecular compound from the adsorbent, A method for adsorbing and desorbing a fluorine-containing low-molecular compound, comprising

[18] An adsorbent containing at least one rubber selected from the group consisting of hydrocarbon rubbers, silicone rubbers, and fluorine rubbers and at least one polymer selected from the group consisting of cured products of the rubbers, The fluorine-containing low-molecular compound adsorbed on the adsorbent, A composition comprising [Advantages of the Invention]

[0007] According to the present disclosure, it is possible to provide a method for adsorbing a fluorine-containing low-molecular compound by adsorbing the fluorine-containing low-molecular compound to an adsorbent containing a polymer. [Embodiments for Carrying Out the Invention]

[0008] (Adsorption Method) The method for adsorbing a fluorine-containing low molecular weight compound of the present disclosure comprises bringing an adsorbent into contact with the fluorine-containing low molecular weight compound to adsorb the fluorine-containing low molecular weight compound on the adsorbent. The adsorbent contains at least one polymer selected from the group consisting of rubber and a cured product of the rubber. The rubber contains at least one rubber selected from the group consisting of hydrocarbon rubber, silicone rubber, and fluororubber.

[0009] By including the above configuration, the adsorption method of the present disclosure can adsorb a fluorine-containing low molecular weight compound on an adsorbent containing a polymer. Further, in the conventional adsorption method, only a specific low molecular weight compound is selectively adsorbed, whereas in the adsorption method of the present disclosure, a single type of adsorbent can adsorb a plurality of different types of fluorine-containing low molecular weight compounds, which may be useful for the recovery of fluorine-containing low molecular weight compounds. Further, when a plurality of fluorine-containing low molecular weight compounds are adsorbed on a single type of adsorbent, each of the plurality of fluorine-containing low molecular weight compounds can be adsorbed on the adsorbent at a specific ratio.

[0010] By bringing the adsorbent into contact with the fluorine-containing low molecular weight compound, the fluorine-containing low molecular weight compound is adsorbed on the adsorbent. For example, the adsorption may be carried out by sequentially performing the following steps. Note that the adsorption method of the present disclosure is not limited to the following steps. i) Enclose the adsorbent in a pressure vessel. ii) Set the inside of the pressure vessel containing the adsorbent to a vacuum condition. iii) Introduce the fluorine-containing low molecular weight compound into the pressure vessel containing the adsorbent until a predetermined pressure is reached.

[0011] As the pressure vessel for enclosing the adsorbent, a conventional pressure vessel can be used. For example, the pressure vessel may be a cylinder vessel. The volume of the pressure vessel is not particularly limited, but may be, for example, 10 ml to 100 ml, and may be, for example, 50 ml. The amount of the adsorbent enclosed in the pressure vessel may be, for example, 1 g to 100 g, 10 to 20 g, and may be, for example, 10 g. The amount of the adsorbent enclosed in the pressure vessel may be 0.01 g / mL to 1 g / ml, 0.1 g / mL to 0.5 g / mL, and may be, for example, 0.2 g / mL.

[0012] Before introducing the fluorine-containing low-molecular compound into the pressure vessel, the inside of the pressure vessel enclosing the adsorbent is set to a vacuum condition. Here, the vacuum condition is not limited to a completely vacuum state, but also includes a substantially vacuum state. Specifically, the pressure inside the pressure vessel enclosing the adsorbent may be -0.1 MPa to -0.01 MPa in gauge pressure, preferably -0.1 MPa to -0.05 MPa, more preferably -0.1 MPa to -0.07 MPa. In one aspect, the pressure inside the pressure vessel enclosing the adsorbent may be -0.1 MPa in gauge pressure.

[0013] The fluorine-containing low-molecular compound is introduced into the pressure vessel until a predetermined pressure is reached. The predetermined pressure (hereinafter also referred to as "introduction pressure") may be set according to the type of the fluorine-containing low-molecular compound to be adsorbed on the adsorbent. For example, the introduction pressure may be, in gauge pressure, preferably 0.001 MPa to 10 MPa, more preferably 0.01 MPa to 5 MPa, and still more preferably 0.1 MPa to 1 MPa.

[0014] When using a hydrocarbon rubber and a fluorine rubber as the adsorbent, the introduction pressure may be, in gauge pressure, 0.1 kPa or more and 50 kPa or less, preferably 0.5 kPa or more and 30 kPa or less, more preferably 1 kPa or more and 10 kPa or less, and particularly preferably 3 kPa or more and 7 kPa or less. For example, the introduction pressure may be 5 kPa.

[0015] When silicone rubber is used as the adsorbent, the introduction pressure may be a gauge pressure of 0.01 MPa or more and 10 MPa or less, preferably 0.05 MPa or more and 5 MPa or less, more preferably 0.1 MPa or more and 3.0 MPa or less, and particularly preferably 0.3 MPa or more and 1.0 MPa or less. For example, the introduction pressure may be 0.8 MPa.

[0016] The time for bringing the adsorbent into contact with the fluorine-containing low molecular weight compound may be set according to the type of the fluorine-containing low molecular weight compound adsorbed on the adsorbent. For example, the time may be 1 minute or more, preferably 30 minutes or more, and more preferably 120 minutes or more.

[0017] (Adsorbent) The adsorbent used in the adsorption method of the present disclosure contains at least one polymer selected from the group consisting of rubber and a cured product of the rubber. In the present specification, rubber means a polymer (i.e., a high molecular weight compound) that is rubbery under normal temperature and pressure and has not been subjected to chemical curing treatment. In the present specification, the cured product of rubber means a polymer obtained by curing rubber by chemical curing treatment. Examples of the above curing treatment include vulcanization and crosslinking.

[0018] The method for curing the rubber is not particularly limited, but examples thereof include a method of curing using a known vulcanizing agent and curing agent. As the vulcanizing agent, organic peroxides such as dicumyl peroxide, benzoyl peroxide, t-butyl hydroperoxide, and 2,4-dichlorobenzoyl peroxide can also be used. Polyols such as bisphenol A can also be used. Further, a known vulcanization accelerator may be used in combination. Examples of known vulcanizing agents include sulfur and 4,4'-dithiomorpholine dimorpholine. Examples of sulfur include powdered sulfur, precipitated sulfur, highly dispersed sulfur, surface-treated sulfur, insoluble sulfur, and the like.

[0019] From the viewpoint of efficiently adsorbing the fluorine-containing low molecular weight compound to the adsorbent, the adsorbent used in the adsorption method of the present disclosure may be particulate. The particle shape of the adsorbent is not particularly limited, and may be, for example, any particle shape of a spherical shape, a flat shape, or an irregular shape. From the viewpoint of easy handling, the particulate adsorbent may adsorb the fluorine-containing low molecular weight compound in a state where the particulate adsorbent is packed in a bag such as a nylon mesh.

[0020] The method for producing the particulate adsorbent is not particularly limited, and may be a conventional method. For example, the particulate adsorbent may be produced by crushing a block or pellet-shaped polymer (e.g., rubber and / or a cured product of rubber) with a crusher. In order to efficiently carry out the crushing, the polymer (e.g., rubber and / or a cured product of rubber) may be frozen with liquid nitrogen or the like, and the frozen polymer may be crushed. Other methods for producing particulate adsorbents include a method in which atoms or molecules are grown and aggregated by chemical reaction to obtain particles. For example, particulate adsorbents may be produced by emulsion polymerization, suspension polymerization, or the like.

[0021] From the viewpoint of efficiently adsorbing fluorine-containing low molecular weight compounds to the adsorbent, the particle diameter of the adsorbent may be less than 1.0 mm, preferably 900 μm or less, more preferably 500 μm or less, even more preferably 300 μm or less, and particularly preferably 150 μm or less.

[0022] From the viewpoint of making the particulate adsorbent easy to handle, the particle diameter of the adsorbent may be 0.1 μm or more, preferably 1 μm or more, more preferably 5 μm or more, and even more preferably 10 μm or more.

[0023] The particle size of the adsorbent means the maximum particle size of the adsorbent. The maximum particle size of the adsorbent can be obtained by measuring with an optical microscope. For example, among the ranges of the visual fields obtained by observing the adsorbent with an optical microscope, the particle size of the particle with the largest particle size may be regarded as the maximum particle size of the adsorbent. The maximum particle size of the adsorbent may be the particle size D99 when the cumulative particle volume from the small particle size side reaches 99% of the total particle volume in the particle size distribution determined by the laser diffraction / scattering method.

[0024] The particle size and the maximum particle size of the adsorbent can be controlled by conventional means. For example, the maximum particle size of the adsorbent can be controlled by adjusting the grinding conditions of the grinder. Alternatively, the maximum particle size of the adsorbent can be adjusted to an adsorbent having a predetermined maximum particle size by classification.

[0025] The rubber contained in the adsorbent used in the adsorption method of the present disclosure is at least one rubber selected from the group consisting of hydrocarbon rubber, silicone rubber, and fluororubber. Hereinafter, hydrocarbon rubber, silicone rubber, and fluororubber will be described.

[0026] [Hydrocarbon rubber] Hydrocarbon rubber means a polymer mainly composed of hydrocarbons.

[0027] In one aspect, the hydrocarbon rubber may be a linear hydrocarbon compound. In one aspect, the hydrocarbon compound may have one or more substituents. In one aspect, the hydrocarbon rubber may contain a double bond in part between the carbon atoms constituting its main chain.

[0028] Examples of the substituent for the hydrocarbon compound include a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms.

[0029] In one aspect, the hydrocarbon rubber may be a diene rubber. The diene rubber means a rubber made from a diene monomer having a conjugated double bond as a raw material, or a rubber made from a diene monomer having a conjugated double bond and one or more vinyl monomers copolymerizable with the diene monomer as raw materials. The diene rubber may be natural rubber and / or synthetic rubber. The diene rubber has a double bond in the main chain.

[0030] In one aspect, the diene rubber may have one or more substituents. Examples of the substituent include a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms.

[0031] In one aspect, the hydrocarbon rubber is -CH 2 -C(-X 1 )=CH-CH 2 -: [wherein: X 1 is a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms] and may contain a monomer unit represented by.

[0032] The monomer unit represented by the above formula may be a monomer unit derived from a diene monomer.

[0033] X 1 is a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms.

[0034] The alkyl having 1 to 6 carbon atoms is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. The alkyl having 1 to 6 carbon atoms may be linear or branched.

[0035] From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, X 1 may be a hydrogen atom.

[0036] In one aspect, the hydrocarbon rubber is the above formula -CH 2 -C(-X 1)=CH-CH 2 In addition to the monomer unit represented by - -CH 2 CHX 2 -: [wherein: X 2 is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyano group, or a phenyl group. It may contain a monomer unit represented by ].

[0037] The monomer unit represented by the above formula may be a monomer unit derived from a vinyl monomer copolymerizable with a diene monomer.

[0038] The alkyl having 1 to 6 carbon atoms is preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. The alkyl having 1 to 6 carbon atoms may be linear or branched.

[0039] From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, X 2 may be a cyano group.

[0040] In the hydrocarbon rubber, the molar ratio of the monomer unit represented by the above formula -CH 2 -C(-X 1 )=CH-CH 2 - and the monomer unit represented by the above formula -CH 2 CHX 2 - is preferably 40 to 90 / 60 to 10, more preferably 45 to 70 / 55 to 30, and still more preferably 50 to 65 / 50 to 35.

[0041] In one aspect, examples of the hydrocarbon rubber include styrene-butadiene rubber (SBR), natural rubber (NR), polybutadiene rubber (BR), polyisoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), isoprene-isobutylene copolymer rubber (IIR), ethylene-propylene-diene copolymer rubber (EPDM), and halogenated butyl rubber (HR).

[0042] In one aspect, from the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, the hydrocarbon rubber may be NBR. From the same viewpoint, the content of acrylonitrile in NBR may be 10 mol% or more and 60 mol% or less, preferably 30 mol% or more and 55 mol% or less, and more preferably 35 mol% or more and 50 mol% or less. The content of acrylonitrile in NBR may be determined in accordance with the method for quantifying acrylonitrile described in "ISO 24698-1 (2008)" or "JIS K 6451-1:2016 Synthetic Rubber - NBR - Method for Determining the Bound Acrylonitrile Content".

[0043] As the hydrocarbon rubber that can be contained in the adsorbent, commercially available products may be used.

[0044] [Silicone rubber] Silicone rubber is a polymer in which an organic group is added to a structure in which silicon atoms are bonded to other silicon atoms via oxygen atoms. In other words, silicone rubber is a polymer having a polyorganosiloxane backbone. The silicone rubber may have a crosslinked structure and can be obtained by crosslinking organosiloxane, which is a silicone rubber precursor.

[0045] The silicone rubber R a SiO (4-a) / 2 : [Wherein: R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different from each other and may be unsubstituted or substituted, a is 1.9 to 2.1.] may contain a compound represented by the average composition formula of

[0046] In the above formula, R is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different from each other and may be unsubstituted or substituted.

[0047] In the above-described monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different from each other and may be unsubstituted or substituted, the "monovalent hydrocarbon group having 1 to 10 carbon atoms" may be linear, branched, or may contain a ring structure.

[0048] In one aspect, the above-mentioned "monovalent hydrocarbon group having 1 to 10 carbon atoms" may preferably be a monovalent hydrocarbon group having 1 to 6 carbon atoms, more preferably a monovalent hydrocarbon group having 1 to 3 carbon atoms.

[0049] R may be an alkyl group, a cycloalkyl group, an alkenyl group, a vinyl group, an aryl group, or a group in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom or a cyano group.

[0050] Specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a cyclohexyl group, an octyl group, a nonyl group, or a decyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group. Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, or a naphthyl group. Examples of the alkenyl group include an alkenyl group having 2 to 10 carbon atoms, for example, an allyl group, a butenyl group, a pentenyl group, or a hexenyl group. From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, R may be a methyl group.

[0051] In one aspect, from the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, the above-mentioned "monovalent hydrocarbon group having 1 to 10 carbon atoms" may be an alkenyl group having 2 to 10 carbon atoms, specifically, a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, etc., or may be a group in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom such as fluorine, bromine, or chlorine, or a cyano group.

[0052] In one aspect, from the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, R may be the same as each other.

[0053] In one aspect, from the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, R is an unsubstituted group.

[0054] In one aspect, a is 1.9 to 2.1.

[0055] The silicone rubber may be a homopolymer composed of one kind of polymer or a copolymer composed of two or more kinds of polymers.

[0056] In one aspect, the silicone rubber may be, for example, polydimethylsiloxane. In one aspect, the silicone rubber may be, for example, a copolymer of dimethylsiloxane and an organosiloxane other than dimethylsiloxane. The organosiloxane other than dimethylsiloxane may be one kind of organosiloxane selected from the group consisting of vinylmethylsiloxane, diphenylsiloxane, and methyltrifluoropropylsiloxane.

[0057] As the silicone rubber that can be contained in the adsorbent, commercially available products may be used.

[0058] [Fluororubber] Fluororubber is a polymer containing fluorine atoms in the molecule. For example, fluororubber may be a hydrocarbon compound substituted by fluorine atoms.

[0059] Fluororubber has the following formula: CF 2 =CR 1 R 2 : [wherein: R 1 is a hydrogen atom or a fluorine atom, and R 2 is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by fluorine atoms, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by fluorine atoms.] It may contain monomer units derived from the fluorine-containing monomer represented by the formula.

[0060] R 1 is a hydrogen atom or a fluorine atom.

[0061] R 2 is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms which may be substituted by a fluorine atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted by a fluorine atom.

[0062] The fluororubber may be a homopolymer composed of one kind of polymer, or may be a copolymer composed of two or more kinds of polymers. From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, the fluororubber may be a copolymer composed of two or more kinds of polymers.

[0063] The copolymer composed of two or more kinds of polymers may contain one or two or more kinds of monomer units derived from the fluorine-containing monomer represented by the above formula CF 2 =CR 1 R 2 For example, the fluororubber may be at least one selected from the group consisting of vinylidene fluoride (VDF) / hexafluoropropylene (HFP) copolymer, VDF / HFP / tetrafluoroethylene (TFE) copolymer, TFE / propylene copolymer, TFE / propylene / VDF copolymer, ethylene / HFP copolymer, ethylene / HFP / VDF copolymer, ethylene / HFP / TFE copolymer, VDF / TFE / perfluoro(alkyl vinyl ether) (PAVE) copolymer, and VDF / chlorotrifluoroethylene (CTFE) copolymer.

[0064] In one aspect, from the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, the fluororubber may be a VDF / HFP copolymer which is a binary system material or a VDF / TFE / HFP copolymer which is a ternary system material, and preferably may be a VDF / HFP copolymer which is a binary system material.

[0065] As the VDF / HFP copolymer, those with a molar ratio of VDF / HFP of 45 to 85 / 55 to 15 are preferred, more preferably 50 to 80 / 50 to 20, and still more preferably 60 to 80 / 40 to 20.

[0066] As the VDF / HFP / TFE copolymer, the molar ratio of VDF / HFP / TFE may be 40 to 80 / 10 to 35 / 10 to 35.

[0067] As the fluororubber that can be contained in the adsorbent, commercially available products may be used.

[0068] [Fluorine-containing low molecular compound] In the adsorption method of the present disclosure, the fluorine-containing low molecular compound adsorbed on the adsorbent means a low molecular compound containing a fluorine atom in the molecule. The above-mentioned fluorine-containing low molecular compound may be a low molecular compound in which some or all of the hydrogen atoms bonded to the carbon atoms, sulfur atoms, silicon atoms, and / or nitrogen atoms in the molecule are substituted by fluorine atoms. The fluorine-containing low molecular compound may contain a halogen atom other than a fluorine atom, for example, it may contain a chlorine atom and / or a bromine atom.

[0069] The molecular weight of the fluorine-containing low molecular compound may be 1000 or less. From the viewpoint of efficiently adsorbing the fluorine-containing compound on the adsorbent, the molecular weight of the fluorine-containing low molecular compound may be 30 or more and 1000 or less, preferably 30 or more and 500 or less, and more preferably 30 or more and 400 or less.

[0070] In one embodiment, the fluorine-containing low molecular weight compound has a saturated vapor pressure in the temperature range from -150°C to 150°C and has one or more fluorine atoms. The saturated vapor pressure means the pressure of the gas when the liquid and gas of the fluorine-containing low molecular weight compound are in an equilibrium state. The saturated vapor pressure may be the saturated vapor pressure when it is equal to the atmospheric pressure. The temperature of the fluorine-containing low molecular weight compound when its saturated vapor pressure is equal to the atmospheric pressure is the boiling point. By using the fluorine-containing low molecular weight compound having a saturated vapor pressure in the above temperature range, it becomes easier to adsorb the fluorine-containing low molecular weight compound onto the adsorbent.

[0071] From the viewpoint of efficiently adsorbing the fluorine-containing low molecular weight compound onto the adsorbent, the fluorine-containing low molecular weight compound may have a saturated vapor pressure in the temperature range from -120°C to 100°C, preferably from -100°C to 60°C, more preferably from -100°C to 20°C, still more preferably from -100°C to -20°C, and particularly preferably from -90°C to -40°C.

[0072] The saturated vapor pressure may be the saturated vapor pressure obtained by a conventional measurement method. For example, the saturated vapor pressure may be determined by a static method, a boiling point method, a DSC method, a gas flow method, or an isoteniscope method.

[0073] The fluorine-containing low molecular weight compound is represented by formula (1) or (2): C p F q Y r : (1) [Wherein, p, q, and r are integers of 1 or more, q + r = 2p + 2, Y each independently represents one kind of atom selected from the group consisting of a halogen atom and a hydrogen atom.] C n F m Z l : (2) [Wherein, n, m, and l are integers of 1 or more, m + l = 2n, n ≧ 2, Z independently represents one kind of atom selected from the group consisting of a halogen atom and a hydrogen atom. It may be at least one fluorocarbon represented by .

[0074] In one aspect, p is 1 or more and 10 or less, q is 2 or more, preferably p is 1 or more and 5 or less, and q may be 2 or more. From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, p may be 1 or 2, and q may be 2 or more.

[0075] In one aspect, Y may be a chlorine atom.

[0076] In one aspect, n is 2 or more and 10 or less, m is 2 or more, preferably n is 2 or more and 5 or less, and m may be 2 or more. From the viewpoint of efficiently adsorbing the fluorine-containing low molecular compound to the adsorbent, n may be 2 or 3, and m may be 2 or more.

[0077] In one aspect, Z may be a hydrogen atom.

[0078] Examples of the fluorine-containing low molecular compound may include one or more fluorine-containing low molecular compounds selected from the group consisting of chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), and hydrofluoroolefin (HFO).

[0079] Examples of CFCs include trichlorofluoromethane (CFC-11), dichlorodifluoromethane (CFC-12), chlorotrifluoromethane (CFC-13), 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113), 1,2-dichlorotetrafluoroethane (CFC-114), or chloropentafluoroethane (CFC-115).

[0080] Examples of HCFCs include chlorodifluoromethane (HCFC-22), 2,2-dichloro-1,1,1-trifluoroethane (HCFC-123), 2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124), 1,1-dichloro-1-fluoroethane (HCFC-141b), 1-chloro-1,1-difluoroethane (HCFC-122b), 3,3-dichloro-1,1,1,2,2-pentafluoropropane (HCFC-225ca), or 1,3-dichloro-1,1,2,2,3-pentafluoropropane (HCFC-225cb).

[0081] Examples of HFCs include trifluoromethane (HFC-23), difluoromethane (HFC-32), 1,1,1,2,2-pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,2-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365mfc).

[0082] Examples of HFOs include 2,3,3,3-tetrafluoropropene (HFO-1234yf) or 1,3,3,3-tetrafluoropropene (HFO-1234ze).

[0083] In one aspect, from the perspective of efficiently adsorbing fluorine-containing low-molecular compounds to the adsorbent, the fluorine-containing low-molecular compound may be at least one fluorine-containing low-molecular compound selected from the group consisting of HFC-32, HFC-125, HCFC-22, HFC-134a, and HFO-1234yf.

[0084] The adsorption method of the present disclosure can control the adsorption amount of the fluorine-containing low-molecular compound onto the adsorbent based on the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular compound. In the adsorption method of the present disclosure, particularly when the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular compound is small, the adsorption amount of the fluorine-containing low-molecular compound onto the adsorbent tends to be large. Based on the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular compound, it becomes easier to adjust the respective ratios of a plurality of different fluorine-containing low-molecular compounds adsorbed on one type of adsorbent.

[0085] The mechanism of the adsorption of the fluorine-containing low-molecular compound onto the adsorbent is not necessarily clear, but the intermolecular force acting between the adsorbent and the fluorine-containing low-molecular compound is considered to be the cause. Regarding the control of the adsorption amount, the electrical interaction is considered to be dominant as the intermolecular force, and it is considered that the electrical interaction is caused by the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular compound.

[0086] The polarizability of the adsorbent is a value obtained by converting the polarizability determined by the density functional theory (DFT) per unit volume. Specifically, for oligomers with a degree of polymerization of 3 or more composed of monomers of the adsorbent, a polarizability calculation is performed on the stable structure obtained by the structure optimization calculation. The polarizability of the adsorbent is a value obtained by dividing the calculated polarizability of the oligomer of the adsorbent by the molecular volume of the oligomer of the adsorbent. In quantum chemical calculations, in the structure optimization calculation, ωB97X-D was used for the exchange-correlation functional, and 6-31G(d,p) was applied as the basis function. In the polarizability calculation, ωB97X-D was used for the exchange-correlation functional, and 6-311++G(2d,p) was applied as the basis function. As the quantum chemical calculation program, Gaussian16, a quantum chemical calculation program manufactured by Gaussian, was used. For the calculation of the molecular volume, RDKit, software for chemoinformatics, was used.

[0087] The polarizability of the fluorine-containing low-molecular-weight compound is a value obtained by converting the polarizability determined by the density functional theory (DFT) per unit volume. Specifically, for the molecule of the fluorine-containing low-molecular-weight compound, a polarizability calculation is performed on the stable structure obtained by the structure optimization calculation. The polarizability of the fluorine-containing low-molecular-weight compound is a value obtained by dividing the calculated polarizability of the fluorine-containing low-molecular-weight compound by the molecular volume of the fluorine-containing low-molecular-weight compound. In quantum chemical calculations, in the structure optimization calculation, ωB97X-D was used for the exchange-correlation functional, and 6-31G(d,p) was applied as the basis function. In the polarizability calculation, ωB97X-D was used for the exchange-correlation functional, and 6-311++G(2d,p) was applied as the basis function. As the quantum chemical calculation program, Gaussian16, a quantum chemical calculation program manufactured by Gaussian, was used. For the calculation of the molecular volume, RDKit, software for chemoinformatics, was used.

[0088] The difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular-weight compound may be set according to the type of the fluorine-containing low-molecular-weight compound adsorbed on the adsorbent. For example, the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular-weight compound may be 0.001 or more and 0.01 or less, preferably 0.003 or more and 0.08 or less, more preferably 0.005 or more and 0.08 or less, and still more preferably 0.007 or more and 0.06 or less. The difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low-molecular-weight compound may be an absolute value.

[0089] (Adsorption and desorption method) Hereinafter, the adsorption and desorption method of the present disclosure will be described.

[0090] The adsorption and desorption method of the present disclosure includes adsorbing a fluorine-containing low-molecular-weight compound by the adsorption method of the present disclosure, and placing the adsorbent adsorbed with the fluorine-containing low-molecular-weight compound under reduced pressure conditions to desorb the fluorine-containing low-molecular-weight compound from the adsorbent.

[0091] An adsorbent that has adsorbed a fluorine-containing low-molecular compound can be obtained by the adsorption method of the present disclosure. The adsorbent that has adsorbed the fluorine-containing low-molecular compound can be placed under reduced pressure conditions to desorb the fluorine-containing low-molecular compound from the adsorbent. For example, the adsorption and desorption can be carried out by sequentially performing the following steps. i) Enclose the adsorbent in a pressure vessel. ii) Set the inside of the pressure vessel enclosing the adsorbent to a vacuum condition. iii) Introduce a fluorine-containing low-molecular compound into the pressure vessel enclosing the adsorbent until a predetermined pressure is reached. iv) After introducing the fluorine-containing low-molecular compound to a predetermined pressure, reduce the pressure inside the pressure vessel.

[0092] In iv), the fluorine-containing low-molecular compound can desorb from the adsorbent placed under reduced pressure, and the pressure inside the container can change. From the pressure change, the adsorption amount of the fluorine-containing low-molecular compound with respect to the adsorbent can be quantified.

[0093] Regarding the above i) to iii), they can be carried out under the same conditions as the adsorption method of the present disclosure.

[0094] The reduced pressure condition in the step of iv) may be a vacuum condition. The vacuum condition in the step of iv) means a gauge pressure of -0.1 MPa to -0.01 MPa, preferably -0.1 MPa to -0.05 MPa, Pa or less, and more preferably -0.1 MPa to -0.07 MPa. In one aspect, the pressure inside the pressure vessel enclosing the adsorbent may be -0.1 MPa in gauge pressure. The fluorine-containing low-molecular compound can desorb from the adsorbent placed under reduced pressure, and the pressure inside the container can change. The quantification of the adsorption amount of the fluorine-containing low-molecular compound with respect to the adsorbent from the pressure change can be applied to the ideal gas state equation of PV=nRT and calculated.

[0095] The time for placing the adsorbent adsorbed with the fluorine-containing low molecular weight compound under reduced pressure conditions can be appropriately selected based on the amount of the fluorine-containing low molecular weight compound desorbed from the adsorbent. From the viewpoint of efficiently desorbing the fluorine-containing low molecular weight compound from the adsorbent, the contact time between the adsorbent and the fluorine-containing low molecular weight compound may be 20 minutes or more and 360 minutes or less, preferably 40 minutes or more and 240 minutes or less, more preferably 60 minutes or more and 180 minutes or less, and particularly preferably 100 minutes or more and 140 minutes or less. In one aspect, the time for placing under reduced pressure conditions may be 120 minutes.

[0096] The temperature under the above vacuum conditions can be appropriately selected based on the amount of the fluorine-containing low molecular weight compound desorbed from the adsorbent. From the viewpoint of efficiently desorbing the fluorine-containing low molecular weight compound from the adsorbent, the temperature at the time of contacting the adsorbent with the fluorine-containing low molecular weight compound may be -50°C or higher and 50°C or lower, preferably -30°C or higher and 30°C or lower, more preferably -15°C or higher and 15°C or lower, and particularly preferably -5°C or higher and 5°C or lower. In one aspect, the temperature at the time of desorbing the fluorine-containing low molecular weight compound from the adsorbent may be 25°C.

[0097] (Composition) Hereinafter, the composition of the present disclosure will be described.

[0098] The composition of the present disclosure includes an adsorbent containing at least one rubber selected from the group consisting of hydrocarbon rubber, silicone rubber, and fluororubber and at least one polymer selected from the group consisting of cured products of the rubber, and a fluorine-containing low molecular weight compound adsorbed on the adsorbent.

[0099] The composition of the present disclosure can be obtained, for example, by the adsorption method of the present disclosure. Specifically, it can be obtained by bringing the adsorbent into contact with the fluorine-containing low molecular weight compound to adsorb the fluorine-containing low molecular weight compound on the adsorbent.

[0100] The composition of the present disclosure can function, for example, as a storage material for storing a fluorine-containing low molecular weight compound or a storage and release material for storing and releasing a fluorine-containing low molecular weight compound.

[0101] The composition of the present disclosure contains a fluorine-containing low-molecular compound. Specifically, the composition of the present disclosure may contain 0.01% by mass or more and 35% by mass or less of the fluorine-containing low-molecular compound based on the total amount of the composition. From the viewpoint of enabling the composition to stably store the fluorine-containing low-molecular compound, the composition of the present disclosure may be 0.01% by mass or more and 30% by mass or less, preferably 0.01% by mass or more and 25% by mass or less of the fluorine-containing low-molecular compound based on the total amount of the composition.

[0102] As described above, the adsorption method, the adsorption / desorption method, and the composition of the present disclosure have been described in detail. Note that the adsorption method, the adsorption / desorption method, the composition, etc. of the present disclosure are not limited to those exemplified above.

Examples

[0103] Hereinafter, the adsorption method and the adsorption / desorption method of the present disclosure will be described with reference to examples, but the present disclosure is not limited to the following examples.

[0104] (Measurement of polarization rate) The polarizability of the adsorbent material is the value obtained by converting the polarizability determined by the density functional theory (DFT) per unit volume. Specifically, for oligomers with a degree of polymerization of 3 or more composed of monomers of the adsorbent, polarizability calculations are performed on the stable structure obtained by the structure optimization calculation. The polarizability of the adsorbent material is the value obtained by dividing the calculated polarizability of the oligomer of the adsorbent by the molecular volume of the oligomer of the adsorbent. The polarizability of the fluorine-containing low-molecular compound is the value obtained by converting the polarizability determined by the density functional theory (DFT) per unit volume. Specifically, for the molecule of the fluorine-containing low-molecular compound, polarizability calculations are performed on the stable structure obtained by the structure optimization calculation. The polarizability of the fluorine-containing low-molecular compound is the value obtained by dividing the calculated polarizability of the fluorine-containing low-molecular compound by the molecular volume of the fluorine-containing low-molecular compound. In quantum chemical calculations, in the structure optimization calculation, ωB97X-D was used for the exchange-correlation functional, and 6-31G(d,p) was applied as the basis function. In the polarizability calculation, ωB97X-D was used for the exchange-correlation functional, and 6-311++G(2d,p) was applied to the basis function. As the quantum chemical calculation program, Gaussian16, a quantum chemical calculation program manufactured by Gaussian, was used. For the calculation of the molecular volume, RDKit, software for chemoinformatics, was used. The polarizability of the adsorbent material and the polarizability of each fluorine-containing low-molecular compound are shown in Table 1 and Table 2.

[0105]

Table 1

[0106]

Table 2

[0107] (Difference between the polarizability of the adsorbent material and the polarizability of the fluorine-containing low-molecular compound) The difference between the polarizability of the adsorbent material and the polarizability of the fluorine-containing low-molecular compound (hereinafter also referred to as the difference in polarizability from the adsorbent material) is represented by (polarizability of the adsorbent material - polarizability of the fluorine-containing low-molecular compound).

[0108] Example 1 As the adsorbent, a rubber material of polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., "KMP-598", linear polydimethylsiloxane) was used. After pulverizing the bulk sample of the rubber material, N 2 A powder with a maximum particle size of 80 μm was prepared using a cryogenic grinder.

[0109] In order to show that the above rubber material adsorbs fluorine-containing low-molecular compounds and desorbs them by reducing the pressure after adsorption, using the above powder, adsorption experiments from the gas phase were carried out using fluorine-containing low-molecular compounds of chlorodifluoromethane (R22) and pentafluoroethane (R125) respectively.

[0110] About 10 g of the powder of the above rubber material was weighed, enclosed in a predetermined pressure vessel, and after setting the inside of the vessel to a temperature of 25 °C and a vacuum condition with a gauge pressure of -0.1 MPa, the fluorine-containing low-molecular compound was introduced until the pressure reached 0.8 MPa for R22 and 0.8 MPa for R125. After the introduction, the pressure change when desorbing in a vacuum at a temperature of 25 °C and a gauge pressure of -0.1 MPa was applied to the ideal gas state equation of PV=nRT to quantify the adsorption amount to the powder. The results of adsorption and desorption are shown in Table 3.

[0111] Example 2 As the adsorbent, a rubber material of acrylonitrile-butadiene rubber (manufactured by JSR, "PN20HA", acrylonitrile content: 41.5%) was used. After pulverizing the bulk sample of the rubber material, N 2 A powder with a maximum particle size of 80 μm was prepared using a cryogenic grinder.

[0112] In order to show that the above rubber material adsorbs fluorine-containing low-molecular compounds and desorbs them by reducing the pressure after adsorption, using the above powder, adsorption experiments from the gas phase were carried out using fluorine-containing low-molecular compounds of R22 and R125 respectively.

[0113] Weighed approximately 10 g of the powder of the above rubber material, enclosed it in a predetermined pressure vessel, and after setting the inside of the vessel to a temperature of 25°C and a vacuum condition with a gauge pressure of -0.1 MPa, introduced a fluorine-containing low molecular compound until a predetermined pressure of 5 kPa was reached. After the introduction, the pressure change during desorption in a vacuum with a gauge pressure of -0.1 MPa was applied to the ideal gas state equation of PV=nRT to quantify the adsorption amount to the powder. The results of adsorption and desorption are shown in Table 3.

[0114] Example 3 Adsorption and desorption of the fluorine-containing low molecular compound were carried out in the same manner as in Example 2, except that vinylidene fluoride-hexafluoropropylene rubber (raw rubber "G-701BP" manufactured by Daikin, binary fluorine rubber) was used as the adsorbent. The results of adsorption and desorption are shown in Table 3.

[0115]

Table 3

[0116] Example 4 As the adsorbent, a rubber material of acrylonitrile-butadiene rubber (manufactured by JSR, "PN20HA", acrylonitrile content: 41.5%) was used. After pulverizing the bulk sample of the rubber material, 2 a powder with a maximum particle diameter of 80 μm was prepared using a cryogenic mill.

[0117] In order to show that the above rubber material adsorbs a fluorine-containing low molecular compound and desorbs by reducing the pressure after adsorption, using the above powder, adsorption experiments from the gas phase were carried out using fluorine-containing low molecular compounds of 1,1,1,2-tetrafluoroethane (R134a) and 2,3,3,3-tetrafluoropropene (R1234yf), respectively.

[0118] Weighed approximately 10 g of the powder of the above rubber material, enclosed it in a predetermined pressure vessel, and after setting the inside of the vessel to a temperature of 25°C and a vacuum condition with a gauge pressure of -0.1 MPa, introduced a fluorine-containing low-molecular compound until a predetermined pressure of 5 kPa was reached. After the introduction, the pressure change when desorbing in a vacuum with a gauge pressure of -0.1 Pa was applied to the ideal gas state equation of PV = nRT to quantify the adsorption amount to the powder. The results of adsorption and desorption are shown in Table 4.

[0119] Example 5 Adsorption and desorption of the fluorine-containing low-molecular compound were carried out in the same manner as in Example 4, except that acrylonitrile-butadiene rubber (manufactured by JSR, "S215SL", acrylonitrile content: 47.5%) was used as the adsorbent. The results of adsorption and desorption are shown in Table 4.

[0120]

Table 4

[0121] From the above results, the fluorine-containing low-molecular compound could be adsorbed to the adsorbent by the adsorption method of the present disclosure. Also, by the adsorption and desorption method of the present disclosure, the fluorine-containing low-molecular compound could be adsorbed to the adsorbent and then desorbed. Furthermore, different types of fluorine-containing low-molecular compounds could be adsorbed and desorbed by one type of adsorbent.

Industrial Applicability

[0122] The adsorption method of the present disclosure can be suitably used for various applications, for example, as a method for recovering fluorine-containing low-molecular compounds.

Claims

1. A method for adsorbing a fluorine-containing low molecular weight compound, comprising the steps of: contacting an adsorbent with the fluorine-containing low molecular weight compound to adsorb the fluorine-containing low molecular weight compound onto the adsorbent; Including, The adsorbent contains at least one polymer selected from the group consisting of rubber and a cured product of the rubber, and does not contain an alkylammonium salt; the rubber includes at least one rubber selected from the group consisting of a hydrocarbon rubber, a silicone rubber, and a fluororubber; The method for adsorbing a fluorine-containing low molecular weight compound, wherein the fluorine-containing low molecular weight compound is one or more selected from the group consisting of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and hydrofluoroolefins (HFOs).

2. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 1 , wherein the adsorbent is in a particulate form.

3. 3. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 2, wherein the particle diameter of the adsorbent is less than 1.0 mm.

4. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 1 , wherein the hydrocarbon rubber is a diene rubber.

5. The hydrocarbon rubber is -CH ２ -C(-X １ )=CH-CH ２ -: [In the formula: X １ is a hydrogen atom, a chlorine atom, or an alkyl group having 1 to 6 carbon atoms. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 1, which comprises a monomer unit represented by the following formula:

6. The hydrocarbon rubber further comprises -CH ２ CHX ２ -: [In the formula: X ２ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cyano group, or a phenyl group. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 5 , which comprises a monomer unit represented by the following formula:

7. The silicone rubber is R ａ SiO （４－ａ）／２ : [In the formula: R are the same or different, unsubstituted or substituted, monovalent hydrocarbon groups having 1 to 10 carbon atoms; a is 1.9 to 2.

1. The method for adsorbing fluorine-containing low molecular weight compounds according to claim 1 , comprising a compound represented by an average composition formula:

8. 8. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 7, wherein R is an alkyl group, a cycloalkyl group, an alkenyl group, a vinyl group, an aryl group, or a group in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms or cyano groups.

9. The fluororubber has the following formula: CF ２ =CR １ R ２ : [In the formula: R １ is a hydrogen atom or a fluorine atom, R ２ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, or an alkoxy group having 1 to 6 carbon atoms which may be substituted with a fluorine atom.

2. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 1, comprising a monomer unit derived from a fluorine-containing monomer represented by the following formula:

10. 2. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 1, wherein the fluorine-containing low molecular weight compound has a saturated vapor pressure in a temperature range of -150°C to 150°C and has one or more fluorine atoms.

11. The fluorine-containing low molecular weight compound is represented by the formula (1) or (2): C ｐ F ｑ Y ｒ : (1) [In the formula, p, q, and r are integers of 1 or more, q+r=2p+2, Each Y independently represents one atom selected from the group consisting of a halogen atom and a hydrogen atom. C ｎ F ｍ Z ｌ : (2) [In the formula, n, m, and l are integers of 1 or more, m+l=2n, n≧2; Each Z independently represents one atom selected from the group consisting of a halogen atom and a hydrogen atom.

2. The method for adsorbing fluorine-containing low molecular weight compounds according to claim 1, wherein the fluorocarbon is at least one kind represented by the formula:

12. 12. The method for adsorbing fluorine-containing low molecular weight compounds according to claim 11, wherein p is 1 or 2, and q is 2 or more.

13. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 12, wherein the halogen atom in Y is a chlorine atom.

14. 12. The method for adsorbing fluorine-containing low molecular weight compounds according to claim 11, wherein n is 2 or 3, and m is 2 or more.

15. The method for adsorbing a fluorine-containing low molecular weight compound according to claim 12, wherein Z is a hydrogen atom.

16. When the same adsorbent is used, 2. The method for adsorbing fluorine-containing low molecular weight compounds according to claim 1, wherein the amount of the fluorine-containing low molecular weight compounds adsorbed onto the adsorbent is controlled based on the difference between the polarizability of the adsorbent and the polarizability of the fluorine-containing low molecular weight compounds.

17. Adsorbing a fluorine-containing low molecular weight compound by the method according to any one of claims 1 to 15; and placing the adsorbent having the fluorine-containing low molecular weight compound adsorbed thereon under reduced pressure conditions, and desorbing the fluorine-containing low molecular weight compound from the adsorbent; Including, The method for adsorption and desorption of a fluorine-containing low molecular weight compound, wherein the fluorine-containing low molecular weight compound is at least one selected from the group consisting of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and hydrofluoroolefins (HFOs).

18. an adsorbent comprising at least one rubber selected from the group consisting of hydrocarbon rubber, silicone rubber, and fluororubber, and at least one polymer selected from the group consisting of cured products of said rubber, and not containing an alkylammonium salt; a fluorine-containing low molecular weight compound adsorbed on the adsorbent; Including, The composition, wherein the fluorine-containing low molecular weight compound is at least one selected from the group consisting of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and hydrofluoroolefins (HFOs).

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