Pervaporation membrane

Abstract

This pervaporation membrane 10A comprises a separation function layer 1. The separation function layer 1 contains a silicone resin. The silicone resin has a crosslinked structure and has a molecular weight between crosslinking points of 2,000 g / mol to 10,000 g / mol. The pervaporation membrane 10A is used in order to, for example, separate organic compounds from an aqueous solution containing volatile organic compounds.

Description

pervaporation membrane

[0001] The present invention relates to pervaporation membranes.

[0002] Microbial fermentation is a known method for obtaining valuable non-petroleum-derived materials. For example, a method has been developed for producing volatile organic compounds (fermented products) such as alcohols by fermenting a carbon source such as glucose using microorganisms. The carbon source is fermented, for example, in an aqueous solution. In this method, the microbial fermentation may stop if the content of the fermented product in the aqueous solution increases. To continuously produce the microbial fermented product, it is necessary to separate the fermented product from the aqueous solution.

[0003] One example of a method for separating volatile organic compounds from an aqueous solution containing the organic compounds is pervaporation (PV) using a pervaporation membrane. Pervaporation is suitable for separating volatile organic compounds from an aqueous solution containing various substances. Pervaporation also tends to reduce energy consumption and carbon dioxide emissions compared to distillation. Patent Document 1 discloses an example of a pervaporation membrane used in pervaporation.

[0004] Japanese Patent Application Publication No. 10-147546

[0005] When a pervaporation membrane is used to separate volatile organic compounds from an aqueous solution containing the organic compounds, there is a demand for improved separation performance.

[0006] The present invention provides a pervaporation membrane having a separation functional layer containing a silicone resin, wherein the silicone resin has a crosslinked structure and a molecular weight between crosslink points of 2,000 g / mol or more and 10,000 g / mol or less.

[0007] According to the present invention, it is possible to provide a pervaporation membrane suitable for improving separation performance when separating volatile organic compounds from an aqueous solution containing the organic compounds.

[0008] Fig. 1 is a cross-sectional view schematically showing a pervaporation membrane according to one embodiment of the present invention; Fig. 2 is a cross-sectional view schematically showing a modified example of a pervaporation membrane; Fig. 3 is a schematic cross-sectional view of a membrane separation device including a pervaporation membrane; Fig. 4 is a perspective view schematically showing a modified example of a membrane separation device; Fig. 5 is a schematic configuration diagram showing an example of a membrane separation system.

[0009] A pervaporation membrane according to a first aspect of the present invention is a pervaporation membrane having a separation functional layer containing a silicone resin, wherein the silicone resin has a crosslinked structure and a molecular weight between crosslink points of 2000 g / mol or more and 10000 g / mol or less.

[0010] In a second aspect of the present invention, for example, in the pervaporation membrane according to the first aspect, the molecular weight between crosslinks is 3000 g / mol or more.

[0011] In a third aspect of the present invention, for example, in the pervaporation membrane according to the first or second aspect, the silicone resin is formed from a silicone resin composition having a solvent content of 5 wt % or less.

[0012] In a fourth aspect of the present invention, for example, in the pervaporation membrane according to any one of the first to third aspects, the silicone resin is formed from an addition type silicone resin composition.

[0013] In a fifth aspect of the present invention, for example, in the pervaporation membrane according to the fourth aspect, the addition-type silicone resin composition includes a silicone base and a curing agent, and the weight-average molecular weight of the silicone base is 10,000 or more and 200,000 or less.

[0014] In a sixth aspect of the present invention, for example, in the pervaporation membrane according to any one of the first to fifth aspects, the separating functional layer has a thickness of 1 μm or more and 50 μm or less.

[0015] In a seventh aspect of the present invention, for example, in the pervaporation membrane according to any one of the first to sixth aspects, the separation functional layer further contains a filler.

[0016] In an eighth aspect of the present invention, for example, in the pervaporation membrane according to the seventh aspect, the filler contains silica.

[0017] In a ninth aspect of the present invention, for example, in the pervaporation membrane according to the seventh or eighth aspect, the filler has a surface modified with a modifying group containing a hydrocarbon group.

[0018] In a tenth aspect of the present invention, for example, the pervaporation membrane according to any one of the first to ninth aspects further comprises a porous support that supports the separating functional layer.

[0019] In an eleventh aspect of the present invention, for example, in the pervaporation membrane according to the tenth aspect, the porous support includes an organic material.

[0020] In a twelfth aspect of the present invention, for example, in the pervaporation membrane according to the tenth or eleventh aspect, the porous support has a main body and a microporous layer disposed on the main body, and the microporous layer comprises polysulfone.

[0021] In a thirteenth aspect of the present invention, for example, the pervaporation membrane according to any one of the first to twelfth aspects is used to separate volatile organic compounds from an aqueous solution containing the organic compounds.

[0022] In a fourteenth aspect of the present invention, for example, in the pervaporation membrane according to the thirteenth aspect, the organic compound is an alcohol.

[0023] The present invention will be described in detail below, but the following description is not intended to limit the present invention to a specific embodiment.

[0024] <Embodiment of Pervaporation Membrane> FIG. 1 is a cross-sectional view schematically illustrating a pervaporation membrane according to one embodiment of the present invention. The pervaporation membrane 10A of this embodiment includes a separation function layer 1 containing a silicone resin. The silicone resin has a cross-linked structure and a molecular weight between cross-linking points of 2,000 g / mol or more and 10,000 g / mol or less. The pervaporation membrane 10A may further include a porous support 5 that supports the separation function layer 1. The separation function layer 1 has, for example, a surface that is in direct contact with the porous support 5 and a surface that is exposed to the outside of the pervaporation membrane 10A. The pervaporation membrane 10A is, for example, composed only of the separation function layer 1 and the porous support 5.

[0025] The pervaporation membrane 10A is typically a membrane (separation membrane) that preferentially allows organic compounds C to permeate from an aqueous solution S containing volatile organic compounds C. The pervaporation membrane 10A is suitable for improving the separation performance of separating organic compounds C from the aqueous solution S, particularly the flux of a permeating fluid that permeates the pervaporation membrane 10A under conditions of low temperature and low pressure.

[0026] (Separation functional layer) The separation functional layer 1 is, for example, a layer that allows preferential permeation of the organic compound C from the above-mentioned aqueous solution S. The separation functional layer 1 is typically a dense layer (non-porous layer) in which no pores are visible when observed at a magnification of 5000 times using a scanning electron microscope (SEM).

[0027] The separation functional layer 1 contains a silicone resin having a crosslinked structure. The molecular weight between crosslink points of the silicone resin is 2000 g / mol or more and 10,000 g / mol or less. According to the inventors' studies, a separation functional layer 1 containing a silicone resin having a molecular weight between crosslink points of 2000 g / mol or more and 10,000 g / mol or less can improve the flux of the permeating fluid passing through the pervaporation membrane 10A. The mechanism of this effect is, for example, as follows. Because the molecular weight between crosslink points of the silicone resin is not too small, the crosslinks are not too dense, and the network is not tightly constrained. Furthermore, because the molecular weight between crosslink points of the silicone resin is not too large, the crosslinks are not too sparse, and the network has appropriate flexibility. As a result, the size of the gaps in the network suitable for the permeation of the permeating fluid can be ensured, and the flux can be improved. If the molecular weight between crosslink points is too small, the gaps in the network become small, and the flux decreases. Furthermore, it is presumed that water, which has a smaller molecular size than the organic compound C, will preferentially permeate, resulting in a decrease in the separation coefficient. If the molecular weight between crosslinks is too large, i.e., if the network is too flexible, large gaps will be formed, as well as small gaps that the permeating fluid cannot pass through. It is presumed that the presence of such areas that the permeating fluid cannot pass through will result in a decrease in flux. The molecular weight between crosslinks of the silicone resin can be adjusted by the structure, number of branches, number of reaction points, molecular weight, etc. of the polyorganosiloxane (typically, polyorganosiloxane P1 and polyorganosiloxane P2 described below) contained in the silicone base and curing agent in the silicone resin composition that forms the silicone resin.

[0028] To further improve the separation performance of the pervaporation membrane 10A, the molecular weight between crosslinking points of the silicone resin is preferably 3000 g / mol or more and 10000 g / mol or less, and more preferably 4000 g / mol or more and 9000 g / mol or less.

[0029] The molecular weight between crosslinking points of the silicone resin, Mc [g / mol], is determined by the density ρ [g / m 3] and the elastic modulus E [Pa] of the silicone resin, it can be calculated using the following formula (1): Mc = 2 (1 + μ) ρRT / E (1) In formula (1), μ is the Poisson's ratio and is set to 0.5. The density ρ is the value at 25°C. R is the gas constant (8.314 J / mol·K). T is the measurement temperature (298.15 K).

[0030] The elastic modulus E of a silicone resin is Young's modulus. The Young's modulus of a silicone resin can be measured by the following method. First, a single-layer film (400 μm thick) of silicone resin is prepared. Next, the single-layer film is cut into a 10 mm x 60 mm strip to prepare a test piece. The test piece is set in a commercially available tensile tester, and a tensile test is performed under the following measurement conditions. (Measurement conditions) Temperature: 25°C Tensile direction: longitudinal direction of test piece Initial chuck distance: 20 mm Tensile speed: 300 mm / min

[0031] Next, a stress-strain curve (SS curve) is created based on the results of the tensile test. A tangent line is drawn at the origin of the SS curve, and the Young's modulus can be calculated from the slope of the tangent line.

[0032] The Young's modulus (elastic modulus E) of the silicone resin is, for example, 4.4 MPa or less, and may be 4.0 MPa or less, 3.0 MPa or less, or even 2.0 MPa or less. The Young's modulus of the silicone resin is, for example, 0.56 MPa or more, 0.60 MPa or more, 0.70 MPa or more, or even 0.80 MPa or more.

[0033] As described above, the separation functional layer 1 contains a silicone resin. The silicone resin is formed, for example, from a silicone resin composition. The silicone resin composition contains, for example, a silicone base material and a curing agent. The silicone base material is, for example, a mixture of polyorganosiloxanes. The curing agent contains, for example, a curing catalyst. The curing agent may further contain polyorganosiloxane in some cases.

[0034] The weight average molecular weight of the silicone base may be 10,000 or more and 200,000 or less, and the weight average molecular weight of the curing agent may be 10,000 or more and 200,000 or less.

[0035] The silicone resin is not particularly limited, and may be, for example, a condensation type silicone resin composition, an addition type silicone resin composition, or a UV-curable silicone resin composition, but an addition type silicone resin composition is preferred. Addition type silicone resin compositions can be cured using almost no metal species (especially tin) that can promote hydrolysis of the silicone resin. Therefore, the separation functional layer 1 containing a silicone resin formed from an addition type silicone resin composition contains almost no metal species that can promote hydrolysis of the silicone resin and tends to have high durability against the above-mentioned aqueous solution S. The silicone resin is preferably formed from a silicone resin composition containing 5 wt % or less of a solvent such as an organic solvent, and more preferably formed from a solventless silicone resin composition that is substantially free of solvents such as an organic solvent.

[0036] [Addition-type silicone resin composition] The addition-type silicone resin composition is a type of silicone resin composition that cures by an addition reaction. The addition-type silicone resin composition contains, for example, a polyorganosiloxane P1 having an alkenyl group and a polyorganosiloxane P2 having a hydrosilyl (SiH) group. It is preferable that the addition-type silicone resin composition further contains a curing catalyst (hydrosilylation catalyst). The addition-type silicone resin composition may be a commercially available silicone resin composition to which a curing catalyst has been added. However, the addition-type silicone resin composition does not necessarily need to contain a curing catalyst.

[0037] The addition-type silicone resin composition can be formed by, for example, heat treatment, whereby the alkenyl groups of the polyorganosiloxane P1 react with the hydrosilyl groups of the polyorganosiloxane P2 (hydrosilylation reaction) to form a silicone resin. In this hydrosilylation reaction, the polyorganosiloxane P2 functions as a crosslinking agent.

[0038] Examples of the alkenyl group of the polyorganosiloxane P1 include a vinyl group and a hexenyl group. The number of alkenyl groups in the polyorganosiloxane P1 is, for example, 2 or more. The alkenyl groups are located, for example, at the terminals of the polyorganosiloxane P1.

[0039] The polyorganosiloxane P1 is, for example, a polyalkylalkylsiloxane such as polydimethylsiloxane (PDMS), polydiethylsiloxane, or polymethylethylsiloxane; a polyalkylarylsiloxane; or a polyorganosiloxane such as poly(dimethylsiloxane-diethylsiloxane) to which an alkenyl group has been introduced. The polyorganosiloxane P1 is preferably PDMS.

[0040] The weight average molecular weight of polyorganosiloxane P1 is, for example, 1000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The larger the weight average molecular weight of polyorganosiloxane P1, the more the separation characteristics of the pervaporation membrane 10A tend to improve. The upper limit of the weight average molecular weight of polyorganosiloxane P1 is not particularly limited, and may be, for example, 1 million, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight average molecular weight of polyorganosiloxane P1 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0041] The number of hydrosilyl groups in the polyorganosiloxane P2 is, for example, at least 2. The hydrosilyl groups may be located at the terminals of the polyorganosiloxane P2 or may be contained in the main chain of the polyorganosiloxane P2.

[0042] Examples of the polyorganosiloxane P2 include polymethylhydrogensiloxane, poly(dimethylsiloxane-methylhydrogensiloxane), and hydrosilyl-terminated polydimethylsiloxane.

[0043] The weight average molecular weight of polyorganosiloxane P2 is, for example, 100 or more, 1000 or more, 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight average molecular weight of polyorganosiloxane P2 is not particularly limited, and may be, for example, 1 million, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight average molecular weight of polyorganosiloxane P2 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0044] The addition-type silicone resin composition contains polyorganosiloxane P1 and polyorganosiloxane P2, and at least one selected from the group consisting of polyorganosiloxane P1 and polyorganosiloxane P2 may have a weight average molecular weight of 10,000 or more and 200,000 or less.

[0045] The weight ratio P2 / P1 of polyorganosiloxane P2 to polyorganosiloxane P1 is, for example, 500 wt% or less, 100 wt% or less, 50 wt% or less, 20 wt% or less, 10 wt% or less, or even 5 wt% or less. The lower limit of the weight ratio P2 / P1 is, for example, 0.01 wt% or more.

[0046] Examples of the curing catalyst include platinum-based catalysts. In other words, the addition-type silicone resin composition may contain a curing catalyst having platinum. Specific examples of platinum-based catalysts include chloroplatinic acid, platinum olefin complexes, and chloroplatinic acid olefin complexes. As described above, the addition-type silicone resin composition may not contain a curing catalyst.

[0047] The addition-type silicone resin composition may contain a compound that generates catalytically active species that catalyze the addition reaction when irradiated with active energy rays such as ultraviolet (UV) rays. With an addition-type silicone resin composition containing this compound, the addition reaction can be promoted by, for example, UV irradiation.

[0048] The addition type silicone resin composition may further contain an organic solvent in addition to the above-mentioned components. Examples of the organic solvent include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. The organic solvent may be used alone or in combination of two or more. The addition type silicone resin composition may contain 5 wt % or less of a solvent such as an organic solvent, or may be a solvent-free composition that is substantially free of a solvent such as an organic solvent.

[0049] [Condensation Type Silicone Resin Composition] The condensation type silicone resin composition is a type of silicone resin composition that cures by a condensation reaction. The condensation type silicone resin composition contains, for example, a polyorganosiloxane P3 having a silanol (SiOH) group and a silane compound P4 having a functional group such as an alkoxy group, an alkenyloxy group, an acyloxy group, an amino group, a ketoxime group, or an amide group. The condensation type silicone resin composition may or may not further contain a curing catalyst. The condensation type silicone resin composition may also be a commercially available silicone resin composition to which a curing catalyst has been added.

[0050] The condensation type silicone resin composition can be formed by, for example, heat treatment, whereby the silanol groups of the polyorganosiloxane P3 react with the functional groups of the silane compound P4 (condensation reaction), in which the silane compound P4 functions as a crosslinking agent.

[0051] The number of silanol groups in polyorganosiloxane P3 is, for example, 2 or more. The silanol groups are located, for example, at the terminals of polyorganosiloxane P3. Polyorganosiloxane P3 may have an alkyl group such as a methyl group or an ethyl group, or a phenyl group introduced as a substituent on the side chain.

[0052] The polyorganosiloxane P3 is, for example, a polyorganosiloxane in which silanol groups have been introduced into the polyorganosiloxane described above for the polyorganosiloxane P1.

[0053] The weight average molecular weight of polyorganosiloxane P3 is, for example, 1000 or more, 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight average molecular weight of polyorganosiloxane P1 is not particularly limited, and may be, for example, 1 million, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight average molecular weight of polyorganosiloxane P3 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0054] As described above, the silane compound P4 has functional groups such as alkoxy groups, alkenyloxy groups, acyloxy groups, amino groups, ketoxime groups, and amide groups. Examples of alkoxy groups include methoxy groups and ethoxy groups. Examples of alkenyloxy groups include isopropenyloxy groups. Examples of acyloxy groups include acetoxy groups. Examples of amino groups include dimethylamino groups, diethylamino groups, and ethylmethylamino groups. Examples of ketoxime groups include acetoxime groups and methylethylketoxime groups. Examples of amide groups include acetamide groups, N-methylacetamide groups, and N-ethylacetamide groups. The number of functional groups in the silane compound P4 is, for example, two or more. In particular, it is preferable that the silane compound P4 contains an alkoxysilyl group as the alkoxy group.

[0055] The silane compound P4 may be a low molecular weight compound having a molecular weight of about 1000 or less, or may be a high molecular weight compound having a polysiloxane skeleton.

[0056] Examples of the curing catalyst include tin-based catalysts, such as organotin catalysts such as dibutyltin dilaurate, dibutyltin diacetate, and dibutyltin dioctate.

[0057] The condensation type silicone resin composition may further contain an organic solvent in addition to the above-mentioned components. Examples of the organic solvent include those described above for the addition type silicone resin composition. The condensation type silicone resin composition may be a solventless type that does not contain a solvent such as an organic solvent.

[0058] [UV-Curable Silicone Resin Composition] A UV-curable silicone resin composition is a type of silicone resin composition that cures upon exposure to ultraviolet (UV) light. In UV-curable silicone resin compositions, the curing reaction proceeds, for example, by radical polymerization, radical addition, ionic polymerization, or the like. A UV-curable silicone resin composition in which the curing reaction proceeds by radical polymerization includes, for example, polyorganosiloxane P5 having a double bond (specifically, a carbon-carbon double bond) derived from an alkenyl group, an acryloyl group, or the like. A UV-curable silicone resin composition in which the curing reaction proceeds by radical addition includes, for example, polyorganosiloxane P5 having a double bond (specifically, a carbon-carbon double bond) derived from an alkenyl group, an acryloyl group, or the like, and compound P6 having a functional group capable of radical addition, such as a thiol group. A UV-curable silicone resin composition in which the curing reaction proceeds by ionic polymerization includes, for example, polyorganosiloxane P7 having a functional group capable of ion polymerization, such as an epoxy group, and a compound that generates catalytically active species that catalyze ionic polymerization upon UV exposure.

[0059] According to a UV-curable silicone resin composition in which the curing reaction proceeds by radical polymerization, for example, upon UV irradiation, a radical polymerization reaction proceeds between double bonds contained in the alkenyl groups, acryloyl groups, etc. of the polyorganosiloxane P5, thereby forming a silicone resin.

[0060] Examples of the alkenyl group of polyorganosiloxane P5 include vinyl groups and hexenyl groups. The number of alkenyl groups in polyorganosiloxane P5 is, for example, 2 or more. The alkenyl groups are located, for example, at the terminals of polyorganosiloxane P5. Polyorganosiloxane P5 may have alkyl groups such as methyl groups and ethyl groups, or phenyl groups introduced as side chain substituents.

[0061] The polyorganosiloxane P5 is, for example, a polyorganosiloxane in which a substituent having a double bond, such as an alkenyl group or an acryloyl group, has been introduced into the polyorganosiloxane described above for the polyorganosiloxane P1.

[0062] The weight average molecular weight of polyorganosiloxane P5 is, for example, 1000 or more, 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight average molecular weight of polyorganosiloxane P5 is not particularly limited, and may be, for example, 1 million, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight average molecular weight of polyorganosiloxane P5 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0063] In a UV-curable silicone resin composition in which the curing reaction proceeds by radical addition, for example, upon UV irradiation, a functional group capable of radical addition contained in compound P6 undergoes radical addition to a double bond contained in an alkenyl group or acryloyl group of polyorganosiloxane P5, thereby proceeding with the radical addition reaction to form a silicone resin.

[0064] In compound P6, functional groups capable of radical addition include, for example, a thiol group, an alkylthiol group, etc. Examples of alkylthiol groups include a mercaptomethyl group, a mercaptoethyl group, etc. The number of functional groups capable of radical addition in compound P6 is, for example, two or more.

[0065] Compound P6 may be a polyorganosiloxane containing a functional group capable of radical addition. The functional group may be located, for example, at the terminal of the polyorganosiloxane. The polyorganosiloxane may have an alkyl group such as a methyl group or an ethyl group, or a phenyl group introduced as a substituent on the side chain.

[0066] Compound P6 is, for example, a polyorganosiloxane as described above for polyorganosiloxane P1 to which a functional group capable of radical addition, such as a thiol group, has been introduced.

[0067] The weight-average molecular weight of compound P6 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of compound P6 is not particularly limited, and may be, for example, 1,000,000 or less, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight-average molecular weight of compound P6 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0068] In the UV-curable silicone resin composition in which the curing reaction proceeds by ionic polymerization, for example, catalytically active species that catalyze ionic polymerization are generated by UV irradiation, and ionic polymerization reaction proceeds between functional groups capable of ionic polymerization contained in polyorganosiloxane P7, thereby forming a silicone resin.

[0069] In polyorganosiloxane P7, the functional group capable of ion polymerization is, for example, an epoxy group. Examples of substituents containing an epoxy group include the epoxy group itself, a glycidyl group, and a glycidyloxypropyl group. The number of functional groups capable of ion polymerization in polyorganosiloxane P7 is, for example, two or more. The functional group capable of ion polymerization is located, for example, at the end of polyorganosiloxane P7. Polyorganosiloxane P7 may have an alkyl group such as a methyl group or an ethyl group, or a phenyl group introduced as a side chain substituent.

[0070] The polyorganosiloxane P7 is, for example, the polyorganosiloxane described above for the polyorganosiloxane P1 to which a functional group capable of ionic polymerization, such as an epoxy group, has been introduced.

[0071] The weight average molecular weight of polyorganosiloxane P7 is, for example, 1000 or more, 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight average molecular weight of polyorganosiloxane P7 is not particularly limited, and may be, for example, 1 million, 500,000 or less, 200,000 or less, 100,000 or less, or even 35,000 or less. The weight average molecular weight of polyorganosiloxane P7 may be 10,000 or more and 500,000 or less, 10,000 or more and 200,000 or less, or 15,000 or more and 35,000 or less.

[0072] The UV-curable silicone resin composition may further contain an organic solvent in addition to the above-mentioned components. Examples of the organic solvent include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. The organic solvent may be used alone or in combination of two or more. The UV-curable silicone resin composition may be a solvent-free type that does not substantially contain a solvent such as an organic solvent.

[0073] The separation functional layer 1 may contain a silicone resin as a main component, or may be composed essentially of a silicone resin. The "main component" refers to the component that is contained in the separation functional layer 1 in the largest amount by weight.

[0074] The thickness of the separation functional layer 1 is, for example, 200 μm or less, and may be 100 μm or less, 50 μm or less, or even 20 μm or less. The thickness of the separation functional layer 1 may be 0.05 μm or more, 0.1 μm or more, 0.5 μm or more, or even 1 μm or more. The thickness of the separation functional layer 1 may be 1 μm or more and 50 μm or less.

[0075] (Porous Support) The porous support 5 supports the separation functional layer 1. The porous support 5 preferably contains an organic material, more preferably consists essentially of an organic material, and even more preferably consists only of an organic material.

[0076] The porous support 5 includes, for example, a main body 6 and a microporous layer 7 disposed on the main body 6. In the pervaporation membrane 10A, the microporous layer 7 is located between the main body 6 and the separation functional layer 1 and is in direct contact with both the main body 6 and the separation functional layer 1. The porous support 5 is typically an ultrafiltration membrane.

[0077] The main body 6 is preferably a fibrous structure. Examples of the fibrous structure include a woven fabric, a nonwoven fabric, and a stretched porous membrane containing fibrils. The fibrous structure is typically a nonwoven fabric or a stretched porous membrane. This can improve the flux of the permeating fluid passing through the pervaporation membrane 10A.

[0078] When the fiber structure is a woven fabric or a nonwoven fabric, examples of the fibers contained in the fiber structure include natural fibers such as wood pulp, cotton, and hemp (e.g., Manila hemp); and chemical fibers (synthetic fibers) such as polyester fiber, rayon, vinylon, acetate fiber, polyvinyl alcohol (PVA) fiber, polyamide fiber, polyolefin fiber, and polyurethane fiber. The main body 6 is, for example, a nonwoven fabric made of polyester fiber. The nonwoven fabric is preferably a polyethylene terephthalate (PET) nonwoven fabric.

[0079] When the fibrous structure is an expanded porous membrane, the fibrous structure preferably contains a fluororesin, such as polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy fluororesin (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), with PTFE being preferred.

[0080] For example, expanded porous PTFE membranes are formed by expanding paste extrusions or cast membranes containing PTFE particles. Expanded porous PTFE membranes are composed of fine PTFE fibrils and may have nodes where the PTFE is in a more aggregated state than the fibrils.

[0081] The main body 6 has an average pore size of, for example, 1 μm to 50 μm.

[0082] Examples of materials for the microporous layer 7 include fluororesins such as polyvinylidene fluoride and polytetrafluoroethylene, polyarylethersulfones such as polysulfone and polyethersulfone, and polyimides, and the microporous layer 7 preferably contains polysulfone. The microporous layer 7 has an average pore size of, for example, 0.01 μm to 0.4 μm.

[0083] The thickness of the porous support 5 is not particularly limited and may be, for example, 10 μm or more, 50 μm or more, or even 100 μm or more. The thickness of the porous support 5 is, for example, 300 μm or less, or may be 200 μm or less.

[0084] The average diameter of the openings on the surface of the porous support 5 facing the separation function layer 1 (the surface of the porous support 5 in contact with the separation function layer 1) is, for example, 1 nm or more and 100 nm or less, and preferably 5 nm or more and 20 nm or less.

[0085] The porosity of the porous support 5 is, for example, 30% or more and 80% or less, and preferably 50% or more and 70% or less.

[0086] In some cases, the porous support 5 may consist of only the main body 6 and not have the microporous layer 7 .

[0087] The surface of the porous support 5 that comes into contact with the separating functional layer 1 may be subjected to an adhesion-facilitating treatment. Examples of the adhesion-facilitating treatment include surface treatments such as corona discharge treatment and plasma treatment.

[0088] The adhesion-facilitating treatment may also be a treatment involving the application of a molecular bonding agent. The molecular bonding agent contains a molecular bonding compound (hereinafter referred to as "compound C1") and, if necessary, a solvent such as an organic solvent or water. Compound C1 has a reactive group F1 capable of reacting with the surface of the porous support 5 and a reactive group F2 capable of reacting with a resin (particularly a silicone resin) contained in the separation functional layer 1. The reactive group F2 may be capable of reacting not only with the silicone resin but also with the surface of the porous support 5.

[0089] The reactive group F1 is, for example, at least one selected from the group consisting of an amino group, an azide group, a mercapto group, an isocyanate group, a ureido group, and an epoxy group, and is typically an azide group. The reactive group F2 is, for example, at least one selected from the group consisting of a silanol group and a group G that generates a silanol group by hydrolysis. A specific example of the group G is an alkoxysilyl group.

[0090] Compound C1 is represented, for example, by the following formula (2): A -Z-R B (2)

[0091] In formula (2), R A represents a reactive group F1 or a monovalent substituent having one or more reactive groups F1, and R B represents a reactive group F2, and Z represents a divalent organic group.

[0092] In formula (2), examples of Z include an alkylene group having 1 to 20 carbon atoms which may have a substituent, an alkenylene group having 2 to 20 carbon atoms which may have a substituent, an alkynylene group having 2 to 20 carbon atoms which may have a substituent, and an arylene group having 6 to 20 carbon atoms which may have a substituent.

[0093] Examples of alkylene groups having 1 to 20 carbon atoms include methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups, with methylene, ethylene, and propylene being preferred, and propylene being more preferred. Examples of alkenylene groups having 2 to 20 carbon atoms include vinylene, propenylene, butenylene, and pentenylene groups. Examples of alkynylene groups having 2 to 20 carbon atoms include ethynylene and propynylene groups. Examples of arylene groups having 6 to 20 carbon atoms include o-phenylene, m-phenylene, p-phenylene, 2,6-naphthylene, and 1,5-naphthylene groups.

[0094] Examples of the substituent that the alkylene group, alkenylene group, and alkynylene group may have include halogen atoms such as a fluorine atom and a chlorine atom; alkoxy groups such as a methoxy group and an ethoxy group; alkylthio groups such as a methylthio group and an ethylthio group; and alkoxycarbonyl groups such as a methoxycarbonyl group and an ethoxycarbonyl group.

[0095] Examples of the substituent that the arylene group may have include a cyano group; a nitro group; a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom; an alkyl group such as a methyl group or an ethyl group; an alkoxy group such as a methoxy group or an ethoxy group; and an alkylthio group such as a methylthio group or an ethylthio group.

[0096] The above-mentioned substituents may be bonded to any position in the alkylene group, alkenylene group, alkynylene group, arylene group, or other group, and a plurality of substituents may be bonded to the same element or different elements.

[0097] R A Examples of the group include groups represented by the following formulas (3) to (5).

[0098] In formulas (3) to (5), * represents a bond to Z in formula (2). 1 represents a divalent hydrocarbon group having 1 to 10 carbon atoms. 2 and R 3 R each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. 4 and R 5 each independently represents a reactive group F1 or a group represented by the above formula (3). 4 and R 5 When R is a group represented by formula (3), * in formula (3) represents a bond to a carbon atom constituting a triazine ring in formula (5). 6 is a single bond or -N(R 7 )- represents a divalent group. 7 represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

[0099] In formula (3), R 1is preferably a divalent hydrocarbon group having 2 to 6 carbon atoms. 1 Examples of the alkylene group include alkylene groups or arylene groups having 1 to 10 carbon atoms, and specific examples include alkylene groups such as an ethylene group and a trimethylene group; and arylene groups such as an o-phenylene group, an m-phenylene group, and a p-phenylene group.

[0100] In formula (3), R 2 and R 3 are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. 2 and R 3 Examples of the alkyl group include alkyl groups, alkynyl groups, and aryl groups having 1 to 20 carbon atoms, and specific examples thereof include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decyl group; alkenyl groups such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 3-butenyl group, 4-pentenyl group, and 5-hexenyl group; alkynyl groups such as ethynyl group, propargyl group, and butynyl group; and aryl groups such as phenyl group, 1-naphthyl group, and 2-naphthyl group.

[0101] In formula (5), R 4 and R 5 are preferably the same reactive group F1.

[0102] In formula (5), R 6 is a single bond or -N(R 7 )- represents a divalent group. 7 The hydrocarbon group of the above R 2 and R 3 Examples of the hydrocarbon group of R include the same as those mentioned above. 6 Preferably, represents —NH—.

[0103] R A is preferably a group represented by formula (5) among the groups represented by formulas (3) to (5), and is a group represented by formula (5) and R 4 or R 5is more preferably an azide group or a group represented by the above formula (3).

[0104] R A Examples of the group include a group represented by the following formula (6).

[0105] In formula (6), * represents a bond to Z in formula (2). 1 ~R 3 and R 6 are the same as those described above for equations (3) and (5), respectively. 1 ~R 3 may be the same or different.

[0106] In formula (2), R B may be a group represented by the following formula (7): —Si(X) a (Y) 3-a (7)

[0107] In formula (7), X represents a hydroxy group or an alkoxy group having 1 to 10 carbon atoms, Y represents a hydrocarbon group having 1 to 20 carbon atoms, and a represents an integer of 1 to 3.

[0108] In formula (7), X is, for example, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, etc., and an ethoxy group is preferable. 2 and R 3 Examples of the hydrocarbon group include those mentioned above.

[0109] R B In the formula (I), X is preferably a hydroxy group or an alkoxy group having 1 to 10 carbon atoms and a is 3, and more preferably X is a hydroxy group or an ethoxy group and a is 3.

[0110] R Ais an amino group, examples of the compound C1 include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyldiethoxymethylsilane, [3-(N,N-dimethylamino)propyl]trimethoxysilane, [3-(phenylamino)propyl]trimethoxysilane, trimethyl[3-(triethoxysilyl)propyl]ammonium chloride, and trimethyl[3-(trimethoxysilyl)propyl]ammonium chloride.

[0111] R A Examples of the compound C1 in which is an azido group include (11-azidoundecyl)trimethoxysilane and (11-azidoundecyl)triethoxysilane.

[0112] R A Examples of the compound C1 in which is a mercapto group include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane.

[0113] R A Examples of the compound C1 in which is an isocyanate group include 3-(trimethoxysilyl)propyl isocyanate and 3-(triethoxysilyl)propyl isocyanate.

[0114] R A Examples of the compound C1 in which is a ureido group include 3-ureidopropyltrimethoxysilane and 3-ureidopropyltriethoxysilane.

[0115] R A Examples of the compound C1 in which is an epoxy group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane.

[0116] R Ais a monovalent substituent having one or more reactive groups F1, examples of the compound C1 include 3-(2-aminoethylamino)propyltrimethoxysilane, 3-(2-aminoethylamino)propyltriethoxysilane, 3-(2-aminoethylamino)propyldimethoxymethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and compounds represented by the following formulas (2-1) to (2-9).

[0117]

[0118] (2-1): N,N'-bis(2-aminoethyl)-6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-2): N,N'-bis(2-aminoethyl)-6-(3-trimethoxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-3): N,N'-bis(2-aminoethyl)-6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-4): N,N'-bis(2-aminomethyl)-6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-5): N,N'-bis(2-aminomethyl)-6-(3-trimethoxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-6): N,N'-bis(2-aminomethyl)-6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (2-7): 6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diazide (2-8): 6-(3-trimethoxysilylpropyl)amino-1,3,5-triazine-2,4-diazide (2-9): 6-(3-triethoxysilylpropyl)amino-1,3,5-triazine-2,4-diazide

[0119] Compound C1 is preferably a compound represented by the above formulas (2-1) to (2-9), and more preferably a compound represented by formula (2-1) or formula (2-9).

[0120] The pervaporation membrane 10A may further include an intermediate layer disposed between the separating functional layer 1 and the porous support 5. The intermediate layer is typically formed from a pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition may be a composition containing a silicone-based polymer (a silicone-based pressure-sensitive adhesive).

[0121] The pervaporation membrane according to this embodiment does not necessarily have to include the porous support 5 .

[0122] (Method for manufacturing pervaporation membrane) The pervaporation membrane 10A can be produced, for example, by forming a separation function layer 1 on the microporous layer 7 of the porous support 5. In detail, first, a coating liquid containing the material of the separation function layer 1 is prepared. The coating liquid is, for example, a silicone resin composition (an addition type silicone resin composition, a condensation type silicone resin composition, or a UV-curable silicone resin composition). Next, a coating film is obtained by applying the coating liquid onto the porous support 5. The separation function layer 1 is formed by curing the coating film. The coating film can be cured at room temperature or in a heated environment. The coating film can also be cured by irradiation with active energy rays such as UV.

[0123] When the coating film is cured by heating, the heating conditions of the coating film are not particularly limited. For example, the heating temperature of the coating film may be 80°C or higher, 90°C or higher, 100°C or higher, or even 120°C or higher. The higher the heating temperature of the coating film, the more sufficiently the curing reaction of the components in the silicone resin composition progresses. The upper limit of the heating temperature of the coating film is not particularly limited, and is, for example, 200°C. The heating time of the coating film can be appropriately adjusted depending on the composition of the silicone resin composition used.

[0124] (Uses of Pervaporation Membrane) The pervaporation membrane 10A of this embodiment is suitable for use in, for example, separating organic compound C from an aqueous solution S containing volatile organic compound C. The organic compound C is not particularly limited as long as it is volatile. In this specification, a "volatile organic compound" refers to, for example, an organic compound having a boiling point of 20°C to 260°C under atmospheric pressure (101.325 kPa). Note that, when the organic compound C has a high concentration in an aqueous solution, it generates an aqueous phase containing water as a main component and an organic phase having a higher content of organic compound C than the aqueous phase. However, the organic compound C may not generate an aqueous phase and an organic phase.

[0125] The number of carbon atoms in the organic compound C is not particularly limited and may be, for example, 10 or less, 8 or less, 6 or less, or even 4 or less. The lower limit of the number of carbon atoms in the organic compound C may be 1 or 2. The organic compound C has a functional group containing an oxygen atom, such as a hydroxyl group, a carbonyl group, an ether group, or an ester group. In the organic compound C, the number of functional groups containing an oxygen atom is typically one.

[0126] Examples of the organic compound C include alcohols, ketones, esters, etc., and are typically alcohols. The alcohol may be an alkyl alcohol composed only of an alkyl group and a hydroxyl group, or an aryl alcohol containing an aryl group and a hydroxyl group. The alkyl alcohol may be linear, branched, or cyclic. Examples of the alkyl alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, t-butanol, and n-pentanol, with n-butanol, 2-butanol, isopropanol, and ethanol being preferred, and n-butanol and isopropanol being more preferred. Examples of the aryl alcohol include phenol, etc.

[0127] The ketone may be a dialkyl ketone consisting of only an alkyl group and a carbonyl group, such as methyl ethyl ketone (MEK) or acetone.

[0128] The ester may be a fatty acid alkyl ester composed only of an alkyl group and an ester group, such as ethyl acetate.

[0129] The organic compound C is not limited to the above-mentioned compounds, and may be an aromatic hydrocarbon such as benzene, toluene, or xylene, or an amide solvent such as N,N-dimethylformamide (DMF) or N-methyl-2-pyrrolidone (NMP).

[0130] The aqueous solution S may contain one type of organic compound C, or may contain two or more types of organic compounds C. The content of the organic compound C in the aqueous solution S may be, for example, 0.5 wt % or more, 1 wt % or more, 2 wt % or more, or even 5 wt % or more. The upper limit of the content of the organic compound C is not particularly limited and may be, for example, 50 wt %.

[0131] The organic compound C may be a fermentation product produced by fermenting a carbon source with a microorganism, or may be alcohol (bioalcohol) produced by a microorganism. That is, the aqueous solution S may be a fermentation liquid containing the organic compound C as a fermentation product. However, the aqueous solution S is not limited to a fermentation liquid, and may be waste liquid or wastewater discharged from a chemical plant or the like.

[0132] The aqueous solution S may further contain other components such as a microorganism that produces a fermented product, a carbon source, a nitrogen source, and inorganic ions in addition to water and the organic compound C. The microorganism that produces the fermented product is typically a fungus. Examples of carbon sources include polysaccharides such as starch and monosaccharides such as glucose.

[0133] (Pervaporation Membrane Characteristics) In the pervaporation membrane 10A, the separation factor of the organic compound C relative to water is not particularly limited. As an example, the separation factor α of n-butanol (BuOH) relative to water in the pervaporation membrane 10A is BuOH is, for example, 8 or more, and may be 10 or more, 13 or more, 15 or more, or even 17 or more. BuOH The upper limit is, for example, 100.

[0134] Separation factor α BuOH can be measured by the following method. With a mixed liquid consisting of BuOH and water in contact with one side of the pervaporation membrane 10A (for example, the main surface of the pervaporation membrane 10A on the separating function layer 1 side), the space adjacent to the other side of the pervaporation membrane 10A (for example, the main surface of the pervaporation membrane 10A on the porous support 5 side) is depressurized. This results in a permeated fluid that has permeated the pervaporation membrane 10A. The weight ratio of water and the weight ratio of BuOH in the permeated fluid are measured. In the above operation, the content of BuOH in the mixed liquid is 0.8 wt %. The mixed liquid that is brought into contact with the pervaporation membrane 10A has a temperature of 30°C. The space adjacent to the other side of the pervaporation membrane 10A is depressurized to 1.5 kPa. Separation factor α BuOH can be calculated from the following formula: A and X B are the weight ratios of BuOH and water in the mixed liquid, respectively. A and Y B are the weight ratios of BuOH and water in the permeated fluid that has permeated the pervaporation membrane 10A, respectively. BuOH = (Y A / Y B ) / (X A / X B )

[0135] The above separation factor α BuOH Under the measurement conditions, the flux of BuOH permeating the pervaporation membrane 10A is not particularly limited, and may be, for example, 0.001 kg / m 2 / hr or more, and may be 0.010 kg / m 2 / hr or more, 0.020kg / m 2 / hr or more, and even 0.025 kg / m 2 The flux of BuOH permeating through the pervaporation membrane 10A may be 1.0 kg / m 2 / hr or less, and may be 0.8 kg / m 2 / hr or less, and even 0.6 kg / m 2 / hr or less.

[0136] Furthermore, the separation coefficient α of isopropanol (IPA) relative to water of the pervaporation membrane 10A isIPA is, for example, 5 or more, and may be 6 or more, or even 7 or more. IPA The upper limit is, for example, 100.

[0137] Separation factor α IPA is the separation factor α except that a mixed liquid containing 10 wt% IPA is used and the temperature of the mixed liquid is 40°C. BuOH can be measured by the same method as

[0138] The above separation factor α IPA Under the measurement conditions, the flux of IPA passing through the pervaporation membrane 10A is not particularly limited, and may be, for example, 0.05 kg / m 2 / hr or more, and may be 0.10 kg / m 2 / hr or more, 0.20kg / m 2 / hr or more, 0.25kg / m 2 / hr or more, and even 0.28 kg / m 2 The flux of IPA permeating the pervaporation membrane 10A may be 1.0 kg / m 2 / hr or less, and may be 0.9 kg / m 2 / hr or less, and even 0.8 kg / m 2 / hr or less.

[0139] In the pervaporation membrane 10A of this embodiment, the separation function layer 1 contains a silicone resin having a molecular weight between crosslinking points of 2000 g / mol or more and 10000 g / mol or less, and therefore tends to have good separation performance for separating organic compound C from aqueous solution S (particularly, the flux of the permeating fluid (organic compound C) passing through the pervaporation membrane).

[0140] <Modified Example of Pervaporation Membrane> Figure 2 is a cross-sectional view schematically showing a modified example of the pervaporation membrane. As shown in Figure 2, in the pervaporation membrane 10B, the separation functional layer 1 has a matrix 2 containing a silicone resin and a filler 3 dispersed in the matrix 2. Except for the above, the structure of the pervaporation membrane 10B is the same as that of the pervaporation membrane 10A. Therefore, elements common to the above-mentioned pervaporation membrane 10A and the modified pervaporation membrane 10B are given the same reference numerals, and their description may be omitted. In other words, the descriptions of each embodiment can be mutually applied as long as there is no technical contradiction. Furthermore, as long as there is no technical contradiction, each embodiment may be combined with each other.

[0141] As described above, in the pervaporation membrane 10B, the separation functional layer 1 further includes filler 3. All or part of the filler 3 is embedded in the matrix 2. Within the matrix 2, all of the filler 3 may be spaced apart from one another, or may be partially aggregated.

[0142] Examples of silicone resins contained in matrix 2 include those described above for pervaporation membrane 10A.

[0143] Filler 3 includes an inorganic material such as zeolite, silica, or bentonite. Filler 3 includes, for example, at least one selected from the group consisting of zeolite and silica, and preferably includes silica. Fillers containing silica tend to have better hydrolysis resistance than fillers containing zeolite. Furthermore, fillers containing silica tend to increase the free volume of the resin (particularly silicone resin) contained in matrix 2. Increasing the free volume of the resin tends to improve the separation characteristics of pervaporation membrane 10B, particularly the flux of the permeating fluid (organic compound C) that permeates the pervaporation membrane. Filler 3 allows for appropriate adjustment of the viscosity of the resin composition, which tends to facilitate the preparation of a resin composition suitable for coating.

[0144] Silica usually means silicon dioxide. Filler 3 may be a silica filler containing silicon dioxide as a main component. Silica filler does not have a crystalline structure, for example. Silica filler can be produced, for example, by reacting metal silicon with oxygen. Silica filler can also be produced by a sol-gel method, a precipitation method, an aqueous solution wet method, or the like. Filler 3 may be substantially composed of silicon dioxide only.

[0145] However, the filler 3 may contain zeolite. Examples of zeolites contained in the filler 3 include high-silica zeolites having a high ratio of silica to alumina, and silicalites that do not contain alumina. Examples of fillers 3 that contain high-silica zeolites include HSZ (registered trademark) manufactured by Tosoh Corporation, HiSiv (registered trademark) manufactured by Union Showa Corporation, USKY (registered trademark) manufactured by Union Showa Corporation, and Zeoal (registered trademark) manufactured by Nakamura Choukou Co., Ltd.

[0146] The filler 3, particularly the silica filler, does not have micropores with a diameter of, for example, 2 nm or less, but may have mesopores with a diameter of 2 nm to 50 nm or macropores with a diameter of 50 nm or more.

[0147] The filler 3, particularly the silica filler, preferably has a surface modified with a modifying group containing a hydrocarbon group. In other words, the filler 3 is preferably surface-modified with a modifying group. The surface-modified filler 3 has high dispersibility in the resin and is suitable for suppressing the occurrence of cracks during the production of the separation functional layer 1, etc.

[0148] The number of carbon atoms in the hydrocarbon group contained in the modifying group is not particularly limited and is, for example, 1 to 25. The number of carbon atoms in the hydrocarbon group may be 5 or less. The hydrocarbon group may be linear, branched, or cyclic. Examples of the hydrocarbon group include alkyl groups such as methyl and ethyl groups.

[0149] The modifying group may further contain a silicon atom, and a hydrocarbon group may be bonded to the silicon atom. The modifying group may contain at least one selected from the group consisting of an organosilyl group and a polyorganosiloxane group. Examples of the organosilyl group include triorganosilyl groups such as trimethylsilyl groups and diorganosilyl groups such as dimethylsilyl groups. Examples of the polyorganosiloxane group include dimethylpolysiloxane groups.

[0150] The surface modification with the modifying group can be carried out, for example, by reacting the hydroxyl groups present on the surface of the filler 3 with a known silane coupling agent.

[0151] Specific examples of surface-modified silica fillers include those available under the trade names "AEROSIL (registered trademark) RX series" (RX50, RX200, RX300, etc.), "AEROSIL (registered trademark) RY series" (RY50, RY200, RY200S, etc.), "AEROSIL (registered trademark) NY series" (NY50, NY50L, etc.), "AEROSIL (registered trademark) NAX series" (NAX50, etc.), and "AEROSIL (registered trademark) R series" (R972, R974, R976, etc.), all of which are manufactured by Nippon Aerosil Co., Ltd.

[0152] From the viewpoint of dispersibility in the resin, it is preferable that the filler 3 be sufficiently surface-modified with a modifying group. In other words, it is preferable that the number of hydroxyl groups present on the surface of the filler 3 is small. Whether the filler 3 is sufficiently surface-modified with a modifying group can be determined, for example, from the pH of the dispersion of the filler 3 or the Hansen solubility parameter (HSP value) of the filler 3. The Hansen solubility parameter is obtained by dividing the solubility parameter introduced by Hildebrand into three components: a dispersion term δD, a polarization term δP, and a hydrogen bonding term δH. Details of the Hansen solubility parameter are disclosed in "Hansen Solubility Parameters; A Users Handbook (CRC Press, 2007)" and the like.

[0153] In this embodiment, the pH of the dispersion of filler 3 measured by the following test is, for example, 4.0 to 9.0, and may be 6.0 to 8.0. The pH of the dispersion is preferably neutral (around pH 7.0). When the pH of the dispersion is neutral, it can be said that the filler 3 has been sufficiently surface-modified with modifying groups, and the number of hydroxyl groups present on the surface is small. Test: A dispersion is prepared by mixing water, methanol, and filler, and the pH of the dispersion is measured. Here, the filler content in the dispersion is 4 wt %, the weight ratio of water to methanol is 1:1, and the temperature of the dispersion is 25°C.

[0154] The shape of the filler 3 is, for example, particulate. In this specification, "particulate" includes spherical, ellipsoidal, scaly, and fibrous shapes. The filler 3 may be powdery. The average particle size of the filler 3 is not particularly limited and may be, for example, 50 μm or less, 20 μm or less, 10 μm or less, 1 μm or less, 500 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, or even 20 nm or less. According to the above configuration, the filler 3 is less likely to detach from the separation functional layer 1. Furthermore, a separation functional layer 1 containing filler 3 with a small average particle size tends to easily disperse stress applied to the separation functional layer 1 and has, for example, high adhesion to the porous support 5. The lower limit of the average particle size of the filler 3 is not particularly limited and is, for example, 1 nm. The average particle size of the filler 3 may be 5 nm or more, 10 nm or more, or even 100 nm or more. In this specification, the average particle size refers to the primary particle size.

[0155] The average particle size of the filler 3 can be determined, for example, by the following method. First, a cross section of the separation functional layer 1 is observed with a transmission electron microscope. In the obtained electron microscope image, the area of ​​a specific filler is calculated by image processing. The diameter of a circle having the same area as the calculated area is regarded as the particle size (particle diameter) of that specific filler. The particle sizes of an arbitrary number (at least 50) of fillers are calculated, and the average of the calculated values ​​is regarded as the average particle size of the filler 3.

[0156] The content of filler 3 in the separation functional layer 1 may be, for example, 1 wt% or more, 5 wt% or more, 10 wt% or more, 20 wt% or more, 30 wt% or more, or even 40 wt% or more. The upper limit of the content of filler 3 in the separation functional layer 1 is not particularly limited and may be, for example, 50 wt% or less, or 20 wt% or less. When the content of filler 3 is 50 wt% or less, a decrease in the flux of the permeating fluid passing through the pervaporation membrane 10B can be prevented. In addition, the occurrence of defects such as cracks tends to be sufficiently suppressed during the production of the separation functional layer 1. The content of filler 3 in the separation functional layer 1 may be 1 wt% or more and 50 wt% or less, or 5 wt% or more and 20 wt% or less.

[0157] The content of the matrix 2 in the separation functional layer 1 is not particularly limited, and may be, for example, 30 wt % to 99 wt %, or may be 30 wt % to 90 wt %.

[0158] The surface area D1 of the filler 3 per weight of the matrix 2 is not particularly limited, and may be, for example, 5 m 2 / g or more, and 2 / g or more, 20m 2 / g or more, 30m 2 / g or more, 40m 2 / g or more, even 50m 2 The upper limit of the surface area D1 is not particularly limited, and may be, for example, 100 m 2 The surface area D1 is the BET specific surface area D2 (m 2 / g), the weight W1 (g) of the matrix 2 contained in the separation functional layer 1, and the weight W2 (g) of the filler 3 contained in the separation functional layer 1, the D1(m 2 / g) = D2(m 2 / g)×W2(g) / W1(g)

[0159] The pervaporation membrane 10B can be produced in the same manner as the above-described pervaporation membrane 10A by further adding filler 3 to the coating liquid containing the material of the separation functional layer 1.

[0160] <Embodiment of Membrane Separation Apparatus> As shown in Figure 3, the membrane separation apparatus 100 of this embodiment includes a pervaporation membrane 10A and a tank 23. In the membrane separation apparatus 100, the pervaporation membrane 10B described in Figure 2 can be used instead of the pervaporation membrane 10A. The tank 23 has a first chamber 21 and a second chamber 22. The first chamber 21 functions as a supply space to which a supply fluid (specifically, the above-mentioned aqueous solution S) is supplied. The second chamber 22 functions as a permeation space to which a permeated fluid S1 is supplied. The permeated fluid S1 is obtained by the aqueous solution S permeating through the pervaporation membrane 10A.

[0161] Pervaporation membrane 10A is disposed inside tank 23. Inside tank 23, pervaporation membrane 10A separates first chamber 21 from second chamber 22. Pervaporation membrane 10A extends from one of a pair of walls of tank 23 to the other.

[0162] The first chamber 21 has an inlet 21a and an outlet 21b. The second chamber 22 has an outlet 22a. The inlet 21a is an opening for supplying the aqueous solution S to the supply space (first chamber 21). The outlet 22a is an opening for discharging the permeated fluid S1 from the permeation space (second chamber 22). The outlet 21b is an opening for discharging the aqueous solution S that has not permeated the pervaporation membrane 10A (non-permeated fluid S2) from the supply space (first chamber 21). The inlet 21a, the outlet 21b, and the outlet 22a are each formed, for example, on a wall surface of the tank 23.

[0163] The membrane separation apparatus 100 is suitable for a continuous membrane separation method, but may also be used for a batch membrane separation method.

[0164] (Method of Operating Membrane Separation Apparatus) The method of operating the membrane separation apparatus 100 is, for example, as follows: First, the aqueous solution S is supplied to the first chamber 21 of the membrane separation apparatus 100 through the inlet 21a. This allows the aqueous solution S to come into contact with one surface of the pervaporation membrane 10A (e.g., the main surface on the separation functional layer 1 side).

[0165] Next, with the aqueous solution S in contact with the one surface of the pervaporation membrane 10A, the space adjacent to the other surface of the pervaporation membrane 10A (e.g., the main surface on the porous support 5 side) is depressurized. Specifically, the pressure inside the second chamber 22 is reduced through the outlet 22a. The pressure inside the second chamber 22 can be reduced by a depressurization device such as a vacuum pump. The pressure in the second chamber 22 is, for example, 50 kPa or less, and may be 20 kPa or less, 10 kPa or less, 5 kPa or less, 3 kPa or less, or even 2 kPa or less. In this specification, unless otherwise specified, "pressure" refers to absolute pressure.

[0166] By reducing the pressure inside the second chamber 22, a permeated fluid S1 having a high content of organic compound C can be obtained on the other side of the pervaporation membrane 10A. In other words, the permeated fluid S1 is supplied to the second chamber 22. In the second chamber 22, the permeated fluid S1 is typically a gas. The permeated fluid S1 is discharged to the outside of the membrane separation device 100 through the outlet 22a.

[0167] On the other hand, the content of the organic compound C in the aqueous solution S gradually decreases from the inlet 21a to the outlet 21b of the first chamber 21. The aqueous solution S treated in the first chamber 21 (non-permeated fluid S2) is discharged to the outside of the membrane separation device 100 through the outlet 21b. The non-permeated fluid S2 is typically a liquid.

[0168] As described above, the pervaporation membrane 10A allows preferential permeation of the organic compounds C contained in the aqueous solution S. Therefore, the permeated fluid S1 obtained by operation of the membrane separation device 100 has a higher content of organic compounds C than the aqueous solution S supplied to the membrane separation device 100.

[0169] <Modifications of Membrane Separation Device> The membrane separation device 100 may be a spiral membrane element, a hollow fiber membrane element, a disk-tube membrane element in which multiple pervaporation membranes are stacked, a plate-and-frame membrane element, or the like. Fig. 4 shows a spiral membrane element. The membrane separation device 110 of Fig. 4 includes a central tube 26 and a stack 27. The stack 27 includes a pervaporation membrane 10A (or a pervaporation membrane 10B).

[0170] The central tube 26 has a cylindrical shape. A plurality of holes or slits are formed on the surface of the central tube 26 to allow the permeation fluid S1 to flow into the interior of the central tube 26. Examples of materials for the central tube 26 include resins such as acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polyphenylene ether resin (PPE resin), and polysulfone resin (PSF resin); and metals such as stainless steel and titanium. The inner diameter of the central tube 26 is, for example, in the range of 20 to 100 mm.

[0171] In addition to the pervaporation membrane 10A, the laminate 27 further includes a feed-side channel material 28 and a permeate-side channel material 29. The laminate 27 is wound around the central tube 26. The membrane separation device 110 may further include an exterior material (not shown).

[0172] As the feed-side flow path material 28 and the permeate-side flow path material 29, for example, a resin net, woven fabric, or knitted fabric made of polyethylene, polypropylene, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or ethylene-chlorotrifluoroethylene copolymer (ECTFE) can be used.

[0173] The membrane separation device 110 can be operated, for example, by the following method. First, the aqueous solution S is supplied to one end of the wound stack 27. The space inside the central tube 26 is depressurized. As a result, the permeated fluid S1 that has permeated the pervaporation membrane 10A of the stack 27 moves into the central tube 26. The permeated fluid S1 is discharged to the outside through the central tube 26. The aqueous solution S (non-permeated fluid S2) that has been treated in the membrane separation device 110 is discharged to the outside from the other end of the wound stack 27.

[0174] <Embodiment of Membrane Separation System> As shown in Fig. 5, a membrane separation system 200 of this embodiment includes the above-described membrane separation device 100. Note that the membrane separation system 200 may include the membrane separation device 110 described in Fig. 4 instead of the membrane separation device 100.

[0175] The membrane separation system 200 further includes a tank 30 in addition to the membrane separation apparatus 100. The tank 30 stores an aqueous solution S to be supplied to the membrane separation apparatus 100. The tank 30 may be a fermenter for producing an organic compound C by fermentation of a carbon source by microorganisms.

[0176] The membrane separation system 200 further includes an aqueous solution supply path 70, a non-permeated fluid discharge path 71, and a permeated fluid discharge path 72. The aqueous solution supply path 70 is a path for supplying the aqueous solution S from the tank 30 to the membrane separation device 100 during operation, and is connected to the outlet 31 of the tank 30 and the inlet 21a of the membrane separation device 100. The aqueous solution supply path 70 is provided with, for example, a pump 50 for controlling the flow rate of the aqueous solution S.

[0177] The non-permeated fluid discharge path 71 is a path for discharging the non-permeated fluid S2 from the membrane separation device 100 during operation, and is connected to the outlet 21b of the membrane separation device 100. For example, a pump 51 for controlling the flow rate of the non-permeated fluid S2 is disposed in the non-permeated fluid discharge path 71. The pump 51 does not necessarily have to be disposed in the non-permeated fluid discharge path 71. The non-permeated fluid discharge path 71 may be connected to the inlet 32 ​​of the tank 30 and configured to send the non-permeated fluid S2 to the tank 30 during operation. That is, during operation, the non-permeated fluid S2 may be mixed with the aqueous solution S in the tank 30 and circulated through the aqueous solution supply path 70 and the non-permeated fluid discharge path 71. When the non-permeated fluid S2 is sent to the tank 30, the aqueous solution S and the non-permeated fluid S2 are mixed in the tank 30, and the content of the organic compound C in the aqueous solution S decreases. When the tank 30 is a fermenter, the decrease in the content of the organic compound C in the aqueous solution S can prevent the fermentation by the microorganisms from stopping, thereby enabling the production of the fermented product to be carried out continuously.

[0178] The permeate discharge path 72 is a path for discharging the permeate fluid S1 from the membrane separation device 100 during operation and is connected to the outlet 22a of the membrane separation device 100. The permeate discharge path 72 is provided with, for example, a pressure reducing device 52. The pressure reducing device 52 can reduce the pressure inside the permeate space of the membrane separation device 100. The pressure reducing device 52 is preferably a vacuum device such as a vacuum pump. The vacuum pump is typically a gas transport vacuum pump, and examples thereof include a reciprocating vacuum pump and a rotary vacuum pump. Examples of reciprocating vacuum pumps include diaphragm-type and oscillating piston-type vacuum pumps. Examples of rotary vacuum pumps include liquid ring pumps; oil rotary pumps (rotary pumps); mechanical booster pumps; and various dry pumps such as roots-type, claw-type, screw-type, turbo-type, and scroll-type pumps. The pump serving as the pressure reducing device 52 may be equipped with a variable speed mechanism for changing the rotation speed, etc. An example of a variable speed mechanism is an inverter that drives the pump motor. By controlling the rotation speed of the pump with the variable speed mechanism, the pressure in the permeate space of the membrane separation device 100 can be adjusted appropriately.

[0179] A heat exchanger for cooling the permeated fluid S1 may be further disposed in the permeated fluid discharge path 72. The heat exchanger can condense the gaseous permeated fluid S1. The heat exchanger is, for example, a gas-liquid heat exchanger that causes heat exchange between a cooling medium such as antifreeze and the gaseous permeated fluid S1. The heat exchanger may be located between the membrane separation apparatus 100 and the pressure reducing device 52 (upstream of the pressure reducing device 52), or may be located between the pressure reducing device 52 and the recovery section 40 (downstream of the pressure reducing device 52), which will be described later.

[0180] The membrane separation system 200 further includes a recovery unit 40. The recovery unit 40 recovers the permeated fluid S1 sent from the membrane separation device 100 and can store the permeated fluid S1, for example. The recovery unit 40 is, for example, a tank that stores the permeated fluid S1. A permeated fluid discharge path 72 is connected to an inlet 41 of the recovery unit 40.

[0181] The membrane separation system 200 may further include a controller 60 that controls each component of the membrane separation system 200. The controller 60 is, for example, a DSP (Digital Signal Processor) including an A / D conversion circuit, an input / output circuit, an arithmetic circuit, a storage device, etc. The controller 60 stores a program for appropriately operating the membrane separation system 200.

[0182] Unless otherwise specified, each of the paths of the membrane separation system 200 is made up of, for example, metal or resin piping.

[0183] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0184] <Preparation of Pervaporation Membrane> (Example 1) A silicone resin composition (coating liquid) was prepared by adding 2 parts by weight of a curing agent containing polyorganosiloxane P1 (SRX212 containing a platinum catalyst, manufactured by Dow-Toray Industries, Inc.) to 100 parts by weight of a silicone base resin (BY24-489, manufactured by Dow-Toray Industries, Inc.), which is a polyorganosiloxane mixture. A coating film (thickness 10 μm) was obtained by applying the coating liquid onto a porous support. CF30-C (a laminate of a polysulfone microporous layer and a PET nonwoven fabric) manufactured by Nitto Denko Corporation was used as the porous support. The coating film was formed on the polysulfone microporous layer of CF30-C. BY24-489 contained polyorganosiloxane P1 and polyorganosiloxane P2.

[0185] Next, the coated film was heated at 150° C. for 10 minutes to be cured, thereby preparing a separation functional layer having a thickness of 3 μm. In this manner, the pervaporation membrane of Example 1 was prepared.

[0186] Example 2 To 100 parts by weight of a silicone base material (BY24-489, manufactured by Dow Toray Industries, Inc.), which is a polyorganosiloxane mixture, 1.8 parts by weight of a curing agent containing polyorganosiloxane P1 (SRX212 containing a platinum catalyst, manufactured by Dow Toray Industries, Inc.) was added, and 10 parts by weight of a silica filler (AEROSIL RX50, manufactured by Nippon Aerosil Co., Ltd.) was further added to obtain a coating solution. A pervaporation membrane of Example 2 was produced in the same manner as in Example 1 except for the above.

[0187] Example 3 A pervaporation membrane of Example 3 was produced in the same manner as in Example 1, except that the silicone base material was changed as shown in Table 1.

[0188] Example 4 A pervaporation membrane of Example 4 was produced in the same manner as in Example 2, except that the silicone base material was changed as shown in Table 1.

[0189] Comparative Example 1 A pervaporation membrane of Comparative Example 1 was produced in the same manner as in Example 1, except that the silicone base material was changed as shown in Table 1.

[0190] Comparative Example 2 A pervaporation membrane of Comparative Example 2 was produced in the same manner as in Example 2, except that the silicone base material was changed as shown in Table 1.

[0191] Comparative Example 3: A coating solution was prepared by adding 10 parts by weight of a curing agent (ELASTOSIL® RT604B, manufactured by Wacker Asahi Kasei Silicones) to 90 parts by weight of a silicone base material (ELASTOSIL® RT604A, manufactured by Wacker Asahi Kasei Silicones). A pervaporation membrane of Comparative Example 3 was prepared in the same manner as in Example 1, except for the above.

[0192] Comparative Example 4: To 90 parts by weight of a silicone base material (ELASTOSIL® RT604A, manufactured by Wacker Asahi Kasei Silicones), 10 parts by weight of a curing agent (ELASTOSIL® RT604B, manufactured by Wacker Asahi Kasei Silicones) was added, and 10 parts by weight of a silica filler (AEROSIL RX50, manufactured by Nippon Aerosil Co., Ltd.) was further added to prepare a coating solution. A pervaporation membrane of Comparative Example 4 was prepared in the same manner as in Example 1, except for the above.

[0193] <Molecular Weight Between Crosslinks of Silicone Resin> First, a layer having the same composition as the matrix (silicone resin) of the separation functional layer provided in the pervaporation membranes of Examples 1 to 4 and Comparative Examples 1 to 4 and having a thickness of 400 μm was prepared on a release liner. A release-treated polyethylene terephthalate (PET) film (Mitsubishi Chemical Corporation, MRE38) was used as the release liner. The above layer was prepared on the release surface of the release liner. Next, the release liner was removed to prepare a single-layer film of silicone resin. The Young's modulus of this free-standing film was measured using the method described above. Furthermore, the molecular weight between crosslinks was calculated based on the Young's modulus using the above formula (1). In measuring the Young's modulus, an Autograph AGS-50NX manufactured by Shimadzu Corporation was used as a tensile tester.

[0194] <Observation of the Structure of the Separation Functional Layer> A scanning electron microscope (SU-3800, manufactured by Hitachi High-Technologies Corporation) was used to observe the cross section of the separation functional layer and measure the thickness of the separation functional layer. The measurement results are shown in Table 1.

[0195] <PV Performance> (BuOH Separation Performance) The separation coefficient α of n-butanol (BuOH) relative to water was measured for the pervaporation membranes prepared in Examples 1 to 4 and Comparative Examples 1 to 4 by the following method. BuOH was measured. First, the pervaporation membrane was cut into a size of 74 mm in diameter to prepare a flat membrane test piece. This test piece was set in a batch-type membrane separation device (cell). A mixed liquid consisting of BuOH and water was supplied to the supply space of this cell. The BuOH content in the mixed liquid was 0.8 wt%.

[0196] Next, the cell was immersed in a water bath, and the temperature of the mixed liquid was adjusted to 30°C. Next, the pressure in the permeation space was reduced to 1.5 kPa while stirring the mixed liquid using a stirrer placed in the cell. This caused the mixed liquid to permeate the pervaporation membrane, and a gaseous permeation fluid was obtained. The gaseous permeation fluid was cooled using a cooling trap using liquid nitrogen, and the permeation fluid was condensed. The composition of the liquid permeation fluid was analyzed using gas chromatography, and based on the obtained results, the separation factor α BuOH , and the flux of BuOH that permeated the pervaporation membrane [kg / m2 / hr] was calculated. The evaluation results are shown in Table 1.

[0197] (IPA Separation Performance) The separation coefficient α of isopropanol (IPA) relative to water was measured for the pervaporation membranes prepared in Examples 2 and 4 and Comparative Examples 2 and 4 by the following method. IPA First, a flat membrane test piece was obtained in the same manner as described above, and the test piece was set in a batch-type membrane separation device (cell). A mixed liquid consisting of IPA and water was supplied to the supply space of this cell. The IPA content in the mixed liquid was 10 wt %.

[0198] Next, the cell was immersed in a water bath, and the temperature of the mixed liquid was adjusted to 40°C. Next, the pressure in the permeation space was reduced to 1.5 kPa while stirring the mixed liquid using a stirrer placed in the cell. This caused the mixed liquid to permeate through the pervaporation membrane, and a gaseous permeation fluid was obtained. The gaseous permeation fluid was cooled using a cooling trap using liquid nitrogen, and the permeation fluid was condensed. The composition of the liquid permeation fluid was analyzed using gas chromatography, and based on the obtained results, the separation factor α IPA , and the flux of IPA that permeated the pervaporation membrane [kg / m 2 / hr] was calculated. The evaluation results are shown in Table 1.

[0199]

[0200] The pervaporation membranes of Examples 1 to 4 have a higher flux of BuOH that permeates the pervaporation membrane than the pervaporation membranes of Comparative Examples 1 to 4, and have a practically acceptable separation factor α BuOH Furthermore, the pervaporation membranes of Examples 2 and 4 had a higher flux of IPA that permeated the pervaporation membrane than the pervaporation membranes of Comparative Examples 2 and 4, and had a practically acceptable separation factor α IPA From the above, the pervaporation membranes of Examples 1 to 4 are suitable for improving separation performance.

[0201] The pervaporation membrane of this embodiment is suitable for separating volatile organic compounds from an aqueous solution containing the organic compounds.

Claims

1. A pervaporation membrane having a separation functional layer containing a silicone resin, wherein the silicone resin has a crosslinked structure and a molecular weight between crosslink points of 2,000 g / mol or more and 10,000 g / mol or less.

2. The pervaporation membrane of claim 1, wherein the molecular weight between crosslinks is 3000 g / mol or more.

3. The pervaporation membrane according to claim 1, wherein the silicone resin is formed from a silicone resin composition containing 5 wt % or less of a solvent.

4. The pervaporation membrane of claim 1, wherein the silicone resin is formed from an addition type silicone resin composition.

5. The pervaporation membrane according to claim 4, wherein the addition-type silicone resin composition comprises a silicone base and a curing agent, and the weight-average molecular weight of the silicone base is 10,000 or more and 200,000 or less.

6. The pervaporation membrane according to claim 1, wherein the thickness of the separation functional layer is 1 μm or more and 50 μm or less.

7. The pervaporation membrane of claim 1, wherein the separation functional layer further comprises a filler.

8. The pervaporation membrane of claim 7, wherein the filler comprises silica.

9. The pervaporation membrane of claim 7, wherein the filler has a surface modified with a modifying group containing a hydrocarbon group.

10. The pervaporation membrane of claim 1, further comprising a porous support that supports the separation functional layer.

11. The pervaporation membrane of claim 10, wherein the porous support comprises an organic material.

12. The pervaporation membrane of claim 10, wherein the porous support has a body portion and a microporous layer disposed on the body portion, the microporous layer comprising polysulfone.

13. The pervaporation membrane of claim 1 used to separate volatile organic compounds from an aqueous solution containing said organic compounds.

14. The pervaporation membrane of claim 13, wherein the organic compound is an alcohol.

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