Photoreactive Liquid Crystal Compound and Liquid Crystal Thin Film

Abstract

To provide a liquid crystal thin film that can remove the object to be removed at a high level and further improve the water permeability.SOLUTION: Provided is a liquid crystal thin film, in which a polymerizable liquid crystal compound exhibiting a smectic structure is polymerized, and in which the polymerizable liquid crystal compound has a hydrophobic part, a hydrophilic part, a photocleavable site, and a polymerizable group, and the hydrophobic part and the hydrophilic part are connected by a photocleavable site.

Description

Technical Field

[0001] The present invention relates to a novel photoreactive liquid crystal compound. Further, the present invention relates to a liquid crystal thin film that can be obtained using the photoreactive liquid crystal compound, and a liquid crystal thin film having a nanostructure. Furthermore, the present invention relates to a composite semipermeable membrane containing any of these liquid crystal thin films. The composite semipermeable membrane of the present invention can be suitably used as a composite semipermeable membrane for water treatment.

Background Art

[0002] Methods for removing and detoxifying harmful substances and pathogens (e.g., pathogenic viruses) in water can be broadly classified into two categories: a method of physically separating the target by filtration or precipitation, and a method of changing the chemical structure of the target by chemicals or ultraviolet rays. The method of filtering harmful substances has the advantage of no generation of harmful by-products due to chemical reactions and no problem of pathogen resistance to chemicals or ultraviolet rays (e.g., norovirus is resistant to chlorine disinfection for drinking water and is not inactivated). On the other hand, this method has the disadvantage that it is difficult to remove filtration targets with a small size.

[0003] Currently, ultrafiltration membranes, nanofiltration membranes, and reverse osmosis membranes are used as membranes for removing nanoparticles such as viruses by filtration. Among them, nanofiltration membranes and reverse osmosis membranes can provide more reliable virus removal because the pores contained in the membranes are small. In addition, as the form of nanofiltration membranes and reverse osmosis membranes, composite semipermeable membranes composed of a microporous support membrane that gives physical strength to the membrane and a separation functional layer that gives substantial separation performance are the mainstream, and there is an advantage that optimal materials can be selected for the microporous support membrane and the separation functional layer, respectively.

[0004] A polymer membrane is one of the materials for the separation functional layer that provides the performance of sufficiently removing targets such as viruses. However, in order to efficiently remove harmful substances in water with a polymer membrane having pores in the nanometer size, it is required to remove the removal target at a high level and have high water permeability. To achieve both, it is required to control the structure (size, etc.) of the nanopores.

[0005] As a method for producing a membrane having an orderly nanopore, a method has been studied in which liquid crystal molecules composed of a hydrophilic part and a hydrophobic part utilize a hydrophilic channel formed by nano-phase separation as a driving force as a water permeation path (Patent Documents 1 to 3). Although a high level of removal rate can be achieved by the nanostructured membranes obtained by these prior arts, there is a demand for further improvement in water permeability.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] An object of the present invention is to provide a liquid crystal thin film capable of removing a target to be removed at a high level and further improving water permeability. Another object of the present invention is to provide a composite semipermeable membrane including such a liquid crystal thin film.

Means for Solving the Problems

[0008] In order to solve the above problems, the inventors of the present invention intensively studied with the aim of forming a nanochannel that is regular and larger than the nanostructured films of the prior art such as Patent Document 3. As a result, they focused on rod-shaped molecules in which the hydrophobic part and the hydrophilic part are connected at a site cleaved by light and which exhibit a liquid crystal phase. Then, by polymerizing this molecule in a liquid crystal state to form a polymer film and then separating the hydrophilic part from the polymer chain by a photoreaction, it was found that the water permeability can be improved while maintaining a high removal rate by uniformly expanding while controlling the size of the nanopores, and the present invention was completed.

[0009] That is, the present invention provides: [1] A liquid crystal thin film obtained by polymerizing a polymerizable liquid crystal compound having a smectic structure, wherein the polymerizable liquid crystal compound has a hydrophobic part, a hydrophilic part, a photocleavable site, and a polymerizable group, and the hydrophobic part and the hydrophilic part are connected at the photocleavable site. [2] The liquid crystal thin film according to [1], wherein the polymerizable group is bonded to the terminal side of the hydrophobic part or the terminal side of the hydrophilic part. [3] The liquid crystal thin film according to [1] or [2], wherein the polymerized liquid crystal thin film is obtained by polymerizing at least one compound represented by the general formula (I). TIFF0007694934000001.tif29165 (In the general formula (I), R 1 , when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R 2 , when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH2O-; Y is a single bond, an oxygen atom or -CH2O-; T is a single bond or a linking site; PC is a photocleavable site; P is a photopolymerizable group; n is an integer of 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group.) [4] The liquid crystal thin film according to [3], wherein the photopolymerizable group is a group represented by the following formula (1) or (2). TIFF0007694934000002.tif29161 (In formula (1), R 3a is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, * indicates the bonding position.) TIFF0007694934000003.tif25168 (In formula (2), R 3b is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, * indicates the bonding position.) [5] The liquid crystal thin film according to [3] or [4], wherein the cationic group is represented by any one of the following formulas (3) to (5). TIFF0007694934000004.tif27161 (In formula (3), R 4 , R 5 and R 6 may be the same or different and are each independently (CH2) k-1 CH3, (CF2) k-1 CF3, (CH2) g (CF2) k-1 CF3 and (CH2CH2O) g CH3, and k and g may be the same or different in each R 4 , R 5 and R 6 , where g is an integer from 1 to 8 and k is an integer from 1 to 8, X - is Cl - , Br - , I - , F - , BF4 - , N(CN)2 - , PF6 - , CF3SO3 - or (CF3 SO 2 )2N - is any of the following.) TIFF0007694934000005.tif28159(In formula (4), R 7 is a linear or branched alkyl group having 1 to 6 carbon atoms, X - is as defined in formula (3).) TIFF0007694934000006.tif23164(In formula (5), X - is as defined in formula (3).) [6] The anionic group is -Bz-O - Y n+ (Bz represents a benzene ring), -SO3 - Y n+ , -COO - Y n+ , -O-CO - =C(CN)2·Y n+ , or -SO2-N - -SO2-CF3·Y n+ (Here, Y n+ is a metal ion or an ammonium ion), the liquid crystal thin film according to [3] or [4]. [7] The neutral group is represented by the following formula (6), the liquid crystal thin film according to [3] or [4]. TIFF0007694934000007.tif24161(In formula (6), t is an integer from 1 to 6.) [8] The photo-cleavable site is represented by the following formula (7), the liquid crystal thin film according to any one of [3] to [7]. TIFF0007694934000008.tif33166(In formula (7), R 8 represents a hydrogen atom or 1 to 3 arbitrary monovalent substituents that can be substituted on the benzene ring (when representing 2 or 3 substituents, they may be the same or different); * indicates the bonding position with T; ** indicates the bonding position with T.) [9] The connecting part of T is -C(=O)-O-, the liquid crystal thin film according to [8].

[10] The liquid crystal thin film according to any one of [1] to [9], having a smectic structure.

[11] The polymerized liquid crystal thin film according to [1] or [2], having a repeating unit derived from at least one monomer represented by the general formula (I). TIFF0007694934000009.tif28163 (In the general formula (I), R 1 when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R 2 when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH2O-; Y is a single bond, an oxygen atom or -CH2O-; T is a single bond or a connecting part; PC is a photocleavable site; P is a photopolymerizable group; n is an integer of 1 to 2; m is an integer of 1 to 12; s is an integer of 1 to 12; L is a cationic group, an anionic group or a neutral group.)

[12] A liquid crystal thin film having nano-sized pores, having a structure in which a hydrophilic part and a photocleavable site are removed from the polymerized liquid crystal thin film according to any one of [1] to

[10] .

[13] A microporous support membrane, and [1] to

[11] The polymerized liquid crystal thin film according to any one of A composite semipermeable membrane containing.

[14] A microporous support membrane, and

[12] The liquid crystal thin film having nano-sized pores according to A composite semipermeable membrane containing.

[15] The composite semipermeable membrane according to

[13] or

[14] , used for water treatment.

[16] A polymerizable liquid crystal compound represented by the following general formula (I). TIFF0007694934000010.tif29165 (In general formula (I), R 1 when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R 2 when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH2O-; Y is a single bond, an oxygen atom or -CH2O-; T is a single bond or a linking site; PC is a photocleavable site; P is a photopolymerizable group; n is an integer from 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group.) A polymerizable composition containing the polymerizable liquid crystal compound described in

[17]

[16] . A polymer obtained by polymerizing the polymerizable liquid crystal compound described in

[18]

[16] or the polymerizable composition described in

[17] .

Advantages of the Invention

[0010] By using the liquid crystal thin film of the present invention, a composite semipermeable membrane with improved water permeability while maintaining a high rejection rate can be provided. The composite semipermeable membrane of the present invention can be preferably used especially as a composite semipermeable membrane for water treatment.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0012] The embodiments of the present invention will be described in detail below.

[0013] 1. Polymerized liquid crystal thin film One embodiment of the present invention is s a liquid crystal thin film in which a polymerizable liquid crystal compound having a mechtic structure is polymerized, the polymerizable liquid crystal compound having a hydrophobic part (hydrophobic portion), a hydrophilic part (hydrophilic portion), a site cleavable by light (photo-cleavable site), and a polymerizable group, and the hydrophobic part and the hydrophilic part being connected by a photo-cleavable site (hereinafter, also referred to as "the polymerized liquid crystal thin film of the present invention", "the liquid crystal thin film of the present invention" or "the liquid crystal thin film A of the present invention").

[0014] In the present invention, it is important that a photo-cleavable site is introduced between the hydrophobic part and the hydrophilic part of the polymerizable liquid crystal compound, and the photo-cleavable site connects the hydrophobic part and the hydrophilic part. Here, the photo-cleavable site can be directly bonded to the hydrophobic part and the hydrophilic part, or can be bonded to the hydrophobic part and / or the hydrophilic part via a linking group.

[0015] In the present invention, the polymerizable group is bonded to the end side of the hydrophobic part or the end side of the hydrophilic part.

[0016] FIG. 1 shows the basic design of the polymerizable liquid crystal compound molecule of the present invention.

[0017] FIG. 2 shows a schematic diagram of the control of liquid crystal nanoholes by a photoreaction in the present invention. In the present invention, by polymerizing the polymerizable liquid crystal compound having the above configuration in a liquid crystal state to form a polymer film, a polymer film having an ordered structure can be obtained (FIG. 2(a)). Thereafter, although details will be described later, by separating the hydrophilic part from the polymer chain by a photoreaction, while controlling the size of the nanoholes, it uniformly expands (FIG. 2(b)). Thereby, the water permeability can be improved while maintaining a high removal rate.

[0018] The polymerized liquid crystal thin film of the present invention is formed by polymerizing a liquid crystal compound having a smectic structure, and the polymerized liquid crystal also has a smectic structure. In the present invention, by using a polymerized liquid crystal having a smectic structure, a high separation property for nanoparticles such as viruses can be imparted by forming a hydrophilic part in a layer shape, thereby increasing a water permeable part. Furthermore, by increasing the area of the hydrophilic part, it becomes possible to increase the amount of water treatment per unit time (membrane permeation flux). In the present invention, further, after forming the polymerized liquid crystal thin film, by removing the hydrophilic part and the photo-cleavable part from the polymerized liquid crystal thin film by a photoreaction, while controlling the size of the nanopores, it uniformly expands (FIG. 2b). As a result, nanoporous pores are formed that improve water permeability while maintaining a high removal rate.

[0019] In a preferred embodiment of the liquid crystal thin film of the present invention, the polymerized liquid crystal thin film is obtained by polymerizing at least one compound represented by the general formula (I).

[0020] TIFF0007694934000011.tif29165

[0021] In the general formula (I), R 1 , when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group.

[0022] In the general formula (I), R 2 , when present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group.

[0023] In one aspect of the present invention, the substituents of R 1 and R 2 do not exist, and the benzene rings of the general formula (I) are all unsubstituted benzene rings.

[0024] In the general formula (I), X is a single bond, an oxygen atom or -CH2O-, and preferably an oxygen atom. In another aspect of the present invention, X is a single bond, and -(CH2) m The group of PC (photocleavable moiety) is directly bonded to

[0025] In general formula (I), Y is a single bond, an oxygen atom or -CH2O-, and preferably, it is an oxygen atom. In another aspect of the present invention, Y is a single bond, and -(CH2) s The group of

[0026] is directly bonded to the benzene ring.

[0027] In one preferred embodiment of the present invention, the photopolymerizable group is a group represented by the following formula (1) or (2).

[0028] TIFF0007694934000012.tif29164

[0029] In formula (1), R 3a is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, and preferably, it is a methyl group.

[0030] In formula (1), * indicates the bonding position.

[0031] TIFF0007694934000013.tif25170

[0032] In formula (2), R 3b is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, and preferably, it is a hydrogen atom.

[0033] In formula (2), * indicates the bonding position.

[0034] In general formula (I), L is a cationic group, an anionic group or a neutral group.

[0035] The cationic group in the general formula (I) is represented by any one of the following formulas (3) to (5).

[0036] TIFF0007694934000014.tif26167

[0037] In formula (3), R 4 , R 5 and R 6 may be the same or different and are each independently (CH2) k-1 CH3, (CF2) k-1 CF3, (CH2) g (CF2) k-1 CF3 and (CH2CH2O) g CH3, and k and g may be the same or different for each R 4 , R 5 and R 6 . Here, g is an integer from 1 to 8, and k is an integer from 1 to 8.

[0038] In formula (3), X - is any one of Cl - , Br - , I - , F - , BF4 - , N(CN)2 - , PF6 - , CF3SO3 - or (CF3SO2)2N - .

[0039] TIFF0007694934000015.tif29161

[0040] In formula (4), R 7 is a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a methyl group.

[0041] In formula (4), X - is as defined in formula (3).

[0042] TIFF0007694934000016.tif23170

[0043] In formula (5), X - is as defined in formula (3).

[0044] The anionic group in general formula (I) is preferably -Bz-O - Y n+ (where Bz represents a benzene ring), -SO3 - Y n+ , -COO - Y n+ , -O-CO - =C(CN)2·Y n+ , or -SO2-N - -SO2-CF3·Y n+ (where Y n+ is a metal ion or an ammonium ion).

[0045] The neutral group in general formula (I) is preferably represented by the following formula (6).

[0046] TIFF0007694934000017.tif26169

[0047] In formula (6), t is an integer from 1 to 6.

[0048] In general formula (I), PC represents a photocleavable moiety. Examples of the photocleavable moiety include an ortho-nitrobenzyl group.

[0049] In one aspect of the present invention, the photocleavable moiety is represented by the following formula (7). TIFF0007694934000018.tif33161

[0050] In formula (7), R 8 represents a hydrogen atom or one to three arbitrary monovalent substituents that can be substituted on the benzene ring (when two or three substituents are shown, they may be the same or different). Examples of the monovalent substituent include, for example, -CH3, -OCH3, -F, -Cl, -Br, -I, etc.

[0051] In one aspect of the present invention, R 8 are all hydrogen atoms.

[0052] In formula (7), * indicates the bonding position to T. In formula (7), ** X indicates the bonding position to

[0053] In general formula (I), T is a single bond or a linking site.

[0054] The linking site of T can be appropriately selected according to the type of the photocleavable site of PC, and it is preferable to select a group that facilitates the progress of the photocleavage reaction. Examples of the linking site of T include, for example, -C(=O)-O-, -O-.

[0055] In one preferred aspect of the present invention, the photocleavable site is represented by the above formula (7), and the linking site of T is -C(=O)-O- (the side bonded to PC).

[0056] In general formula (I), n is an integer of 1 to 2, preferably 1.

[0057] In general formula (I), m is an integer of 1 to 12, preferably an integer of 3 to 12.

[0058] In general formula (I), s is an integer of 1 to 12, preferably an integer of 4 to 12. ;

[0059] The compound of general formula (I) may be used alone in one kind for high differentiation, or may be used in combination of two or more kinds for polymerization.

[0060] In one preferred aspect of the present invention, the compound represented by general formula (I) is represented by the following formula (Ia). In formula (Ia) of TIFF0007694934000019, Y, P, m, s, and L are the same as those detailed above for general formula (I).

[0061] In another embodiment of the present invention, the polymerized liquid crystal thin film has repeating units derived from at least one compound (monomer) represented by general formula (I).

[0062] TIFF0007694934000020.tif29165

[0063] Here, R 1 and R 2 , X, Y, P, PC, T, n, m, s, and L are the same as those detailed in the above embodiment (i.e., the polymerized liquid crystal thin film A is obtained by polymerizing at least one compound represented by general formula (I)).

[0064] There is no particular limitation on the molecular weight range of the polymerized liquid crystal, but from the viewpoint of structural stability, it is desirable that the number average molecular weight is 10,000 or more, preferably tens of thousands or more. Also, there is no particular limitation on the molecular weight distribution of the polymerized liquid crystal.

[0065] The production methods of representative compounds of the compounds represented by general formula (I) are specifically shown in the examples of this specification. Therefore, those skilled in the art can, based on these descriptions, appropriately select reaction raw materials, reaction conditions, reaction reagents, etc., and modify or change these methods as necessary to produce the compounds represented by general formula (I).

[0066] 2. Liquid crystal thin film having nano-sized pores Another embodiment of the present invention is a liquid crystal thin film having nano-sized pores, which has a structure in which the hydrophilic part and the photo-cleavable site are removed from the polymerized liquid crystal thin film of the present invention (hereinafter, also referred to as "the liquid crystal thin film having nano-sized pores of the present invention" or "the liquid crystal thin film B of the present invention").

[0067] The liquid crystal thin film B of the present invention is formed by subjecting the polymerized liquid crystal thin film of the present invention to a photoreaction to remove a hydrophilic portion and a photocleavable site from the polymerized liquid crystal thin film. As schematically shown in FIG. 2, first, a polymerizable liquid crystal compound is polymerized in a liquid crystal state to form a polymer film, whereby a polymer film having an ordered structure (the liquid crystal thin film of the present invention) can be obtained (FIG. 2(a)). Then, the liquid crystal thin film of the present invention is subjected to a photoreaction, and by cleaving the hydrophilic portion from the polymer chain by the photoreaction, it expands uniformly while controlling the size of the nanopores (FIG. 2(b)). More specifically, after the photoreaction, the liquid crystal thin film is washed with methanol or the like, whereby the hydrophilic portion and the remaining base portion after photocleavage can be removed. The liquid crystal thin film B of the present invention thus obtained can improve the water permeability while maintaining a high removal rate.

[0068] When the liquid crystal thin film B of the present invention is used in a composite semipermeable membrane, it functions as a separation functional layer having substantially separation performance.

[0069] When the polymerized liquid crystal thin film is obtained by polymerizing at least one of the compounds represented by the following general formula (I), the liquid crystal thin film B of the present invention has a structure in which the portion of PC-X-(CH2) m -L is removed from the polymerized liquid crystal thin film. TIFF0007694934000021.tif29165 (In the general formula (I), R 1 When present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R 2 When present, is a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH2O-; Y is a single bond, an oxygen atom or -CH2O-; T is a single bond or a linking site; PC is a photocleavable site; P is a photopolymerizable group; n is an integer of 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group.)

[0070] The thicknesses of the liquid crystal thin film A of the present invention and the liquid crystal thin film B formed therefrom are preferably in the range of 5 to 500 nm. More preferably, the lower limit of the thickness of these liquid crystal thin films is 10 nm, and the upper limit is more preferably 200 nm. By thinning these liquid crystal thin films, it becomes difficult for cracks to occur, and it is possible to avoid a decrease in solute removal performance due to film defects generated by cracks. Furthermore, the thus-thinned liquid crystal thin film has high water permeability.

[0071] The liquid crystal thin film B of the present invention is a polymerizable liquid crystal compound having a hydrophobic part, a hydrophilic part, a photocleavable site, and a polymerizable group, wherein the hydrophobic part and the hydrophilic part are connected by a photocleavable site, and the liquid crystal compound exhibiting a smectic structure is polymerized to form a polymerized liquid crystal thin film A, and then a hydrophilic part and a photocleavable site are removed from the polymerized liquid crystal thin film A by a photoreaction to form a nano-sized pore.

[0072] The size of the pores of the liquid crystal thin film B is usually 0.4 to 4 nm, preferably 0.4 to 2 nm.

[0073] 3. Composite semipermeable membrane Another embodiment of the present invention is a composite semipermeable membrane including a microporous support membrane and the polymerized liquid crystal thin film of the present invention (hereinafter also referred to as "the composite semipermeable membrane 1 of the present invention").

[0074] The composite semipermeable membrane 1 of the present invention is composed of a microporous support membrane and a polymerized liquid crystal thin film, and the polymerized liquid crystal thin film is provided by coating on the microporous support membrane.

[0075] Another embodiment of the present invention is a composite semipermeable membrane including a microporous support membrane and the liquid crystal thin film B of the present invention (hereinafter also referred to as "the composite semipermeable membrane 2 of the present invention"). That is, the composite semipermeable membrane 2 of the present invention is a composite semipermeable membrane including a microporous support membrane and the liquid crystal thin film B of the present invention. The liquid crystal thin film B is a polymerizable liquid crystal compound having a hydrophobic part, a hydrophilic part, a photocleavable site, and a polymerizable group, and the hydrophobic part and the hydrophilic part are connected by a photocleavable site. After polymerizing the liquid crystal compound exhibiting a smectic structure to form a polymerized liquid crystal thin film A, a composite semipermeable membrane for water treatment having nanosized pores formed by removing the hydrophilic part and the photocleavable site from the polymerized liquid crystal thin film A by a photoreaction.

[0076] Hereinafter, the composite semipermeable membrane 1 of the present invention and the composite semipermeable membrane 2 of the present invention are also collectively referred to as "the composite semipermeable membrane of the present invention".

[0077] Microporous support membrane In the composite semipermeable membrane of the present invention, the microporous support membrane is for imparting strength to a separation functional layer having substantially the separation performance of nanoparticles such as viruses. The pore size and distribution on the surface of the microporous support membrane used in the present invention are not particularly limited. For example, a support membrane having uniform pores or pores gradually increasing in size from the surface on the side where the separation functional layer is formed to the other side, and having a micropore size of 1 nm or more and 100 nm or less on the surface where the separation functional layer is formed is preferred. If the pore diameter on the surface of the microporous support membrane is within this range, the resulting composite semipermeable membrane has high water permeability and can maintain its structure without the separation functional layer falling into the pores of the microporous support membrane during pressurized operation.

[0078] The thickness of the microporous support membrane is preferably in the range of 1 μm to 5 mm, and more preferably in the range of 10 to 100 μm. When the thickness is small, the strength of the microporous support membrane tends to decrease, and as a result, the strength of the composite semipermeable membrane tends to decrease. When the thickness is large, it becomes difficult to handle when bending the microporous support membrane and the composite semipermeable membrane obtained therefrom. In addition, in order to increase the strength of the composite semipermeable membrane, the microporous support membrane may be reinforced with cloth, non-woven fabric, paper, etc. The preferred thickness of these reinforcing materials is 50 to 150 μm.

[0079] The material used for the microporous support membrane is not particularly limited. For example, homopolymers or copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulose-based polymers, vinyl-based polymers, polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfone, and polyphenylene oxide can be used. These polymers can be used alone or in blends. Among the above, examples of cellulose-based polymers include cellulose acetate and cellulose nitrate. Preferred examples of vinyl-based polymers include polyethylene, polypropylene, polyvinyl chloride, and polyacrylonitrile. Among them, homopolymers and copolymers such as polysulfone, polyethersulfone, polyamide, polyester, cellulose acetate, cellulose nitrate, polyvinyl chloride, polyacrylonitrile, polyphenylene sulfide, and polyphenylene sulfide sulfone are preferred. Furthermore, among these materials, it is particularly preferable to use polysulfone and polyethersulfone, which have high chemical stability, mechanical strength, and thermal stability and are easy to mold.

[0080] Method for producing the composite semipermeable membrane of the present invention Next, the method for producing the composite semipermeable membrane of the present invention will be described. The method exemplified for forming the polymerized liquid crystal thin film, which is the separation functional layer, on the microporous support membrane includes a step of forming a liquid crystal thin film on the microporous support membrane and a step of polymerizing the liquid crystal to polymerize it.

[0081] The method for forming a liquid crystal thin film on the microporous support membrane is not particularly limited. For example, a method of applying a liquid crystal solution on the microporous support membrane and then removing the solvent, a method of transferring a liquid crystal thin film formed on a peelable substrate onto the microporous support membrane, and the like can be mentioned.

[0082] The method of applying the liquid crystal solution onto the microporous support film is not particularly limited, but a method that can apply it uniformly is preferred. For example, methods of applying the liquid crystal solution using devices such as a spin coater, a wire bar, a flow coater, a die coater, a roll coater, and a spray can be mentioned. As the solvent of the liquid crystal solution, as long as it does not dissolve the microporous support film and can dissolve the liquid crystal and, if necessary, the polymerization initiator added, it is not particularly limited. The removal of the solvent of the liquid crystal solution can be carried out by known methods and is not particularly limited, but it is preferably removed sufficiently by heating or reducing the pressure so as not to interfere with the self-organization of the liquid crystal.

[0083] The formation of the liquid crystal thin film on the releasable substrate can be carried out by known methods and is not particularly limited. However, a method of removing the solvent after applying the liquid crystal solution onto the releasable substrate is preferably used. In this method, the film thickness of the liquid crystal thin film can be easily controlled according to the coating conditions such as the liquid crystal concentration. As the releasable substrate, materials such as glass, metal, silicon wafer, and polymer can be used without particular limitation. Further, if necessary, a releasable substrate surface-treated by silicon coating, corona discharge, or the like can also be used. The method of applying the liquid crystal solution onto the releasable substrate is not particularly limited, but a method that can apply it uniformly is preferred. For example, methods of applying the liquid crystal solution using devices such as a spin coater, a wire bar, a flow coater, a die coater, a roll coater, and a spray can be mentioned. As the solvent of the liquid crystal solution, as long as it does not dissolve the releasable substrate and can dissolve the liquid crystal and, if necessary, the polymerization initiator added, it is not particularly limited. The removal of the solvent of the liquid crystal solution can be carried out by known methods and is not particularly limited, but it is preferably removed sufficiently by heating or reducing the pressure so as not to interfere with the self-organization of the liquid crystal.

[0084] Subsequently, after bringing the surface of the liquid crystal thin film formed on the releasable substrate into contact with the surface of the microporous support film, the liquid crystal is polymerized to form a polymerized liquid crystal thin film A. At this stage, by peeling off the releasable substrate, the composite semipermeable membrane 1 of the present invention can also be obtained. After forming the liquid crystal thin film A, subsequently, a liquid crystal thin film B is formed by removing a hydrophilic part and a photo-cleavable site from the polymerized liquid crystal thin film A by a photoreaction. After performing the photoreaction, by washing the liquid crystal thin film with methanol or the like, the hydrophilic part and the remaining base part after photo-cleavage can be removed. Thereafter, by peeling the peelable substrate, the target composite semipermeable membrane (the composite semipermeable membrane 2 of the present invention) can be obtained.

[0085] Examples of the method for polymerizing the liquid crystal to form a polymer include heat treatment, electromagnetic wave irradiation, electron beam irradiation, plasma irradiation, etc. Here, the electromagnetic wave includes infrared rays, ultraviolet rays, X-rays, γ-rays, etc. The polymerization method may be appropriately and optimally selected, but from the viewpoints of running cost, productivity, etc., polymerization by electromagnetic wave irradiation is preferable. Among electromagnetic waves, irradiation with infrared rays, visible light, or ultraviolet rays is more preferable from the viewpoint of simplicity because the polymerization reaction proceeds. When actually performing polymerization using electromagnetic waves, these light sources do not necessarily need to selectively generate only light in this wavelength range, and those including electromagnetic waves in these wavelength ranges are sufficient. However, from the viewpoints of shortening the polymerization time and ease of controlling the polymerization conditions, etc., it is preferable that the intensity of these electromagnetic waves is higher than that of electromagnetic waves in other wavelength ranges.

[0086] Electromagnetic waves can be generated using a halogen lamp, xenon lamp, excimer lamp, metal halide lamp, rare gas fluorescent lamp, mercury lamp, light-emitting diode, etc. The energy of the electromagnetic wave is not particularly limited as long as the polymerization reaction proceeds and the liquid crystal structure is not destroyed. The thickness and morphology of the separation functional layer according to the present invention may vary greatly depending on the respective polymerization conditions, and in the case of polymerization by electromagnetic waves, they may vary depending on the wavelength, intensity, distance from the irradiated object, and treatment time of the electromagnetic wave. Therefore, it is necessary to appropriately optimize these conditions. In particular, the reaction temperature is an important factor for maintaining the ordered structure of the liquid crystal, and it is necessary to control it within the temperature range in which the liquid crystal phase is exhibited according to the structure of the liquid crystal.

[0087] In the method for producing the composite semipermeable membrane of the present invention, it is preferable to add a polymerization initiator, a polymerization accelerator, etc. to the liquid crystal for the purpose of increasing the polymerization reaction rate. Here, the polymerization initiator and the polymerization accelerator are not particularly limited and are appropriately selected according to the structure of the liquid crystal, the polymerization method, etc.

[0088] As the polymerization initiator, any known one can be used without particular limitation as long as it is soluble in the solvent to be used. For example, as initiators for polymerization by electromagnetic waves, benzoin ether, dialkylbenzyl ketal, dialkoxyacetophenone, acylphosphine oxide or bisacylphosphine oxide, α-diketone (e.g., 9,10-phenanthrenequinone), diacetylquinone, furylquinone, anisylquinone, 4,4'-dichlorobenzylquinone and 4,4'-dialkoxybenzylquinone, and camphorquinone are exemplified. As initiators for polymerization by heat, azo compounds (e.g., 2,2'-azobis(isobutyronitrile) (AIBN) or azobis-(4-cyanovaleric acid)), or peroxides (e.g., dibenzoyl peroxide, dilauroyl peroxide, tert-butyl peroctoate, tert-butyl perbenzoate or di-(tert-butyl) peroxide), further aromatic diazonium salts, bissulfonium salts, aromatic iodonium salts, aromatic sulfonium salts, potassium persulfate, ammonium persulfate, alkyllithium, cumyl potassium, sodium naphthalene, distyryldianion, etc. are exemplified. Among the initiators for polymerization by heat, benzopinacol and 2,2'-dialkylbenzopinacol are particularly preferable as initiators for radical polymerization.

[0089] Peroxides and α-diketones are preferably used in combination with aromatic amines to accelerate the initiation reaction. This combination is also called a redox system. Examples of such systems include combinations of benzoyl peroxide or camphor quinone with amines (e.g., N,N-dimethyl-p-toluidine, N,N-dihydroxyethyl-p-toluidine, ethyl p-dimethyl-aminobenzoate or its derivatives). Furthermore, systems containing peroxides in combination with ascorbic acid, barbiturate or sulfinic acid as reducing agents are also preferred.

[0090] The addition amount of the polymerization initiator is preferably 5% by weight or less based on the liquid crystal because too much addition will inhibit the self-organization of the liquid crystal.

[0091] Examples of the method for photoreacting the polymerized liquid crystal thin film A include electromagnetic wave irradiation, electron beam irradiation, plasma irradiation, etc. Here, the electromagnetic wave includes infrared rays, ultraviolet rays, X-rays, γ-rays, etc. The method of the photoreaction may be appropriately and optimally selected, but electromagnetic wave irradiation is preferred from the viewpoints of running cost, productivity, etc. Among the electromagnetic waves, infrared rays, visible light, and ultraviolet rays are more preferred from the viewpoint of simplicity. When actually using infrared rays or ultraviolet rays, these light sources do not necessarily need to selectively generate only light in this wavelength range, and those including electromagnetic waves in these wavelength ranges are sufficient. However, from the viewpoints of shortening the photoreaction time and easy control of the reaction conditions, etc., it is preferred that the intensity of these electromagnetic waves is higher than that of electromagnetic waves in other wavelength ranges. The electromagnetic wave can be generated using a halogen lamp, xenon lamp, excimer lamp, metal halide lamp, rare gas fluorescent lamp, mercury lamp, light-emitting diode, etc. The energy of the electromagnetic wave is not particularly limited as long as the photoreaction proceeds.

[0092] The composite semipermeable membrane of the present invention obtained in this way can be used as it is, but it is preferable to hydrophilize the surface of the membrane with, for example, an aqueous solution containing alcohol or an aqueous alkali solution before use.

[0093] The composite semipermeable membrane of the present invention can be suitably used for water treatment.

[0094] The composite semipermeable membrane of the present invention is wound around a cylindrical water collecting pipe with a large number of holes, together with a raw water flow path material such as a plastic net, a permeated water flow path material such as a tricot, and a film for enhancing pressure resistance as needed, and is suitably used as a spiral-type composite semipermeable membrane element. Furthermore, a composite semipermeable membrane module can be formed by connecting these elements in series or in parallel and storing them in a pressure vessel.

[0095] In addition, the above composite semipermeable membrane, its element, and module can be combined with a pump for supplying raw water thereto, a device for pretreating the raw water, etc. to constitute a fluid separation device. By using this separation device, raw water can be separated into permeated water such as drinking water and concentrated water that has not permeated through the membrane, and water suitable for the purpose can be obtained.

[0096] Although the salt rejection rate improves with a higher operating pressure of the fluid separation device, the energy required for operation also increases. Also, considering the durability of the composite semipermeable membrane, the operating pressure when permeating the water to be treated through the composite semipermeable membrane is preferably 0.1 MPa or more and 10 MPa or less. When the supply water temperature increases, the salt rejection rate decreases, but as it decreases, the membrane permeation flux also decreases, so it is preferably 5°C or more and 45°C or less. Also, when the supply water pH is high, in the case of supply water with a high salt concentration such as seawater, there is a risk of scale generation such as magnesium, and there is concern about membrane deterioration due to high pH operation, so operation in the neutral region is preferred.

[0097] Examples of the raw water treated by the composite semipermeable membrane of the present invention include tap water, seawater, brackish water, river water, lake water, groundwater, wastewater, etc., in the range of 10 1 ~10 8 liquid mixtures containing viruses at 10 PFU (plaque forming unit) / mL. In addition, the raw water treated by the composite semipermeable membrane of the present invention contains 10 1 ~10 8Also included are biopharmaceuticals (containing therapeutic proteins, antibodies, hormones, etc.), aqueous desiccant solutions, liquid media for cell culture bioreactors, etc., containing viruses at PFU (plaque forming unit) / mL. The types of viruses blocked by the composite semipermeable membrane of the present invention are not particularly limited, and include pathogenic viruses (for example, norovirus, hepatitis E virus, hepatitis C virus, etc.) and non-pathogenic viruses (bacteriophage Qβ, bacteriophage MS2, etc.).

[0098] 4. Polymerizable liquid crystal compound Another embodiment of the present invention is a polymerizable liquid crystal compound represented by the following general formula (I) (hereinafter also referred to as "the polymerizable liquid crystal compound of the present invention").

[0099] TIFF0007694934000022.tif29165

[0100] Here, R 1 , R 2 , X, Y, P, PC, T, n, m, s, L are the same as those detailed in the composite semipermeable membrane for water treatment of the present invention described above.

[0101] In one preferred aspect of the polymerizable liquid crystal compound of the present invention, the compound represented by the general formula (I) is represented by the following formula (Ia). TIFF0007694934000023.tif33162In formula (Ia), Y, P, m, s, L are the same as those detailed for the general formula (I) in the composite semipermeable membrane for water treatment of the present invention described above.

[0102] Another aspect of the present invention is a polymerizable composition containing the polymerizable liquid crystal compound of the present invention.

[0103] Another aspect of the present invention is a polymer obtained by polymerizing the polymerizable liquid crystal compound and the above polymerizable composition of the present invention.

Examples

[0104] The present invention will be described in more detail by way of examples below, but the present invention is not limited in any way by these examples.

[0105] [Synthesis Example 1] Compound 1a was synthesized according to the following reaction scheme 1. Reaction Scheme 1 TIFF0007694934000024.tif81170Reaction Scheme 1: Synthetic route of Compound 1 Outline of reagents and reaction conditions used: (i) 11-bromo-1-undecanol, potassium carbonate, reacted at 80 °C for 10 hours in N,N-dimethylformamide solvent, yield 92%; (ii) sodium hydroxide, reacted at 80 °C for 2 hours in ethanol solvent, yield 85%; iv) acryloyl chloride, dimethylaniline, reacted at 45 °C for 4 hours in 1,4-dioxane solvent, yield 95%; (v) N,N'-dicyclohexylcarbodiimide, 4-dimethylaminopyridine, reacted at room temperature for 1 day in a dichloromethane / acetonitrile mixed solvent, yield 51 - 59%.

[0106] (1) Synthesis of methyl 4'-(11-hydroxyundecyloxy)-4-biphenylcarboxylate (Compound 4) Compound 4 was synthesized by a general ether synthesis process. Compound 3 (1 g, 4.38 mmol) synthesized according to Reference 1 was dissolved and dispersed in 40 mL of dehydrated N,N-dimethylformamide together with 11-bromo-1-undecanol (1.65 g, 6.57 mmol) and potassium carbonate (1.21 g, 8.76 mmol), and heated at 80 °C for 10 hours with stirring under an argon atmosphere. After the reaction solution was cooled to room temperature, it was poured into 300 mL of water. The reaction product was extracted 3 times with ethyl acetate, and the extract was washed with water and brine, and then water was removed with magnesium sulfate. The extract was concentrated and purified by silica gel column chromatography (developing solvent: dichloromethane / methanol = 95 / 5) to obtain Compound 4 as a white solid (1.66 g, yield 92%). 11H NMR (400 MHz, CDCl3): δ 8.06 (d, 2H, J = 8.8 Hz), 7.60 (dd, 4H, J = 6.4, 16.4, 9.2 Hz), 6.97 (d, 2H, J = 6 Hz), 4.0 (t, 2H, J = 8 Hz), 3.93 (s, 3H), 3.64 (t, 2H, J = 6.4, 7.2 Hz), 1.79 (m, 2H), 1.55 (m, 2H), 1.47 (m, 2H), 1.30 (m, 12H).

[0107] (2) Synthesis of 4'-(11-hydroxyundecyloxy)-4-biphenylcarboxylic acid (Compound 5) Compound 5 was obtained by a general ester hydrolysis reaction. Compound 4 (1.5 g, 3.63 mmol) and sodium hydroxide (0.72 g, 18.17 mmol) were dissolved in a mixed solvent of ethanol (50 mL) and water (5 mL), and stirred at 80 °C for 2 hours. After adding hydrochloric acid to make the reaction solution acidic, it was extracted twice with ethyl acetate. The organic layer was dried over magnesium sulfate, and then the solvent was removed under reduced pressure to obtain a white solid. The solid was washed twice with acetone to obtain Compound 5 as a white solid (1.19 g, yield 85%). 1 1H NMR (400 MHz, CDCl3): δ 8.07 (d, 2H, J = 8.4 Hz), 7.58 (dd, 4H, J = 6.4, 16.4, 9.2 Hz), 6.99 (d, 2H, J = 6.4 Hz), 4.0 (t, 2H, J = 8.8 Hz), 3.72 (t, 2H, J = 6.4 Hz), 1.80 (m, 2H), 1.58 (m, 2H), 1.47 (m, 2H), 1.29 (m, 12H).

[0108] (3) Synthesis of 4'-(11-acryloyloxyundecyloxy)-4-biphenylcarboxylic acid (Compound 6) Compound 5 (1 g, 3.01 mmol), N,N-dimethylaniline (0.364 g, 3.01 mmol), and 1,4-benzoquinone (0.5 mg) were dissolved in dehydrated 1,4-dioxane (30 mL), acryloyl chloride (0.5 mL, 6.02 mmol) was added, and the mixture was stirred at 45 °C for 4 hours under an argon atmosphere in the dark. After the reaction solution was cooled to room temperature, it was poured into 100 mL of water. The extraction operation was carried out three times with ethyl acetate, and the obtained organic layer was washed once with water and once with brine. After the solution was concentrated, it was purified by silica gel column chromatography (developing solvent: dichloromethane / methanol = 95 / 5) to obtain Compound 6 as a white solid (1.25 g, yield 95%). 1 H NMR (400 MHz, CDCl3): δ 8.14 (d, 2H, J = 8 Hz), 7.65 (d, 2H, J = 8.8 Hz), 7.58 (d, 2H, J = 8 Hz), 6.99 (d, 2H, J = 8 Hz), 6.4 (d, 1H, J = 16 Hz), 6.12 (q, 1H, J = 10.4, 6.8, 10.8 Hz), 5.81 (d, 1H, J = 10.4 Hz), 4.15 (t, 2H, J = 6.8 Hz), 4.01 (t, 2H, J = 6.8, 6.4 Hz), 1.81 (quin, 2H, J = 6.8, 6.8, 8.4, 6.4 Hz), 1.66 (quin, 2H, J = 7.2 Hz), 1.46 (quin, 2H, J = 7.2, 8.4, 7.2, 8.0 Hz), 1.31 (m, 12H).

[0109] (4) Synthesis of 3-(3-{3-[4'-(11-acryloyloxyundecyloxy)biphenyl-4-carbonyl-oxymethyl]-4-nitrophenoxy}propyl)-1-methyl-3H-imidazolium dicyanamide (Compound 1a) Compound 6 (0.6 g, 1.37 mmol) synthesized by the above method and compound 7a (0.98 g, 2.73 mmol) synthesized in the same manner as reported in Reference 2 were dissolved in a mixed solvent of dehydrated acetonitrile (30 mL) and dehydrated dichloromethane (20 mL). 4-Dimethylaminopyridine (33.42 mg, 0.27 mmol) and https: / / en.wikipedia.org / wiki / N,N%2527-Dicyclohexylcarbodiimide (0.564 g, 2.73 mmol) were added, and the reaction was carried out at room temperature for 24 hours under light-shielded conditions. The reaction solution was concentrated and purified by silica gel column chromatography (developing solvent: dichloromethane / methanol = 80 / 20) to obtain compound 1a as a white solid (0.62 g, 58%). 1 H NMR (400 MHz, CDCl3): δ 9.20 (s, 1H), 8.19 (d, J = 9.2 Hz, 1H), 8.13 (d, J = 8.4 Hz, 2H), 7.67 (d, J = 8.4 Hz, 2H), 7.57 (d, J = 6.8 Hz, 2H), 7.35 (s, 1H), 7.23 (s, 1H), 7.06 (s, 1H), 6.98 (d, J = 10.4 Hz, 2H), 6.94 (dd, J = 2.8, 6.8, 2.4 Hz, 1H), 6.39 (d, J = 17.6 Hz, 1H), 6.11 (q, J = 10.4, 6.8, 10.4 Hz, 1H), 5.81 (d, J = 10.6 Hz, 1H), 5.76 (s,2H), 4.49 (t, J = 6.8 Hz, 2H), 4.16 (m, 4H), 3.99 (t, J = 6.8, 6.4 Hz, 2H), 3.95 (s, 3H), 2.45 (t, J = 5.6, 6 Hz, 2H), 1.80 (quin, J = 6.8, 6.8, 8.4, 6.4 Hz, 2H), 1.66 (quin, J = 6.8, 7.6, 7.2, 6.8 Hz, 2H), 1.46 (quin, J = 7.6, 7.6, 7.2, 6.8 Hz, 2H), 1.30 (m, 12H).

[0110] [Synthesis Examples 2 - 3] Compounds 7b and 7c were synthesized in the same manner as reported in Reference 2. Compounds 1b and 1c were synthesized in the same manner as Compound 1a, using 7b and 7c respectively instead of Compound 7a. The yields were 55% and 51% respectively. For Compound 1b 1 H NMR (400 MHz, CDCl3): δ 9.19 (s, 1H), 8.21 (d, J = 8.8 Hz, 1H), 8.14 (d, J = 8.4 Hz, 2H), 7.66 (d, J = 8.8 Hz, 2H), 7.57 (d, J = 8.4 Hz, 2H), 7.30 (d, J = 10.4, 2H), 7.10 (s, 1H), 6.99 (d, J = 9.2 Hz, 2H), 6.91 (dd, J = 2.4, 6.8, 2.4 Hz, 1H), 6.39 (d, J = 17.6 Hz, 1H), 6.12 (q, J = 10.8, 7.2, 10.4 Hz, 1H), 5.81 (d, J = 10.4 Hz, 1H), 5.78 (s, 2H), 4.20 (t, J = 7.2, 8 Hz, 2H), 4.14 (t, J = 6.8 Hz, 2H), 4.00 (m, 7H), 1.88 (m, 2H), 1.79 (hept, J = 6.8, 6.8, 6.8, 5.6, 7.6, 7.2 Hz, 4H), 1.66 (quin, J = 6.8, 7.6, 7.2, 6.8 Hz, 2H), 1.33 (m, 24H). For Compound 1c 11H NMR (400 MHz, CDCl3): δ 9.16 (s, 1H), 8.20 (d, J = 9.2 Hz, 1H), 8.12 (d, J = 8.4 Hz, 2H), 7.65 (d, J = 8.8 Hz, 2H), 7.56 (dd, J = 1.6, 5.2, 1.6 Hz, 2H), 7.31 (d, J = 14.8 Hz, 2H), 7.10 (d, J = 2.8 Hz, 1H), 6.98 (d, J = 8.8 Hz, 2H), 6.89 (dd, J = 2.8, 6.8, 2.8 Hz, 1H), 6.38 (d, J = 17.6 Hz, 1H), 6.10 (q, J = 10.4, 7.6, 10.4 Hz, 1H), 5.81 (d, J = 2 Hz, 1H), 5.78 (s, 2H), 4.21 (t, J = 7.2, 8 Hz, 2H), 4.13 (t, J = 6.8, 6.8 Hz, 2H), 4.01 (m, 7H), 1.88 (quin, J = 6.8, 7.6, 7.2, 7.6 Hz, 2H), 1.77 (m, 4H), 1.65 (quin, J = 10.4, 7.2, 7.6, 6.8 Hz, 2H), 1.35 (m, 30H).

[0111] References: 1) A. V. Ustinov, V. V. Shmanai, K. Patel, I. A. Stepanova, I. A. Prokhorenko, I. V. Astakhova, A. D. Malakhov, M. V. Skorobogatyi, P. L. Bernad Jr, S. Khan, M. Shahgholi, E. M. Southern, V. A. Korshun, M. S. Shchepinov, Org. Biomol. Chem. 2008, 6, 4593-4608. 2) M. Gupta, Y. Suzuki, T. Sakamoto, M. Yoshio, S. Torii, H. Katayama, T. Kato, ACS Macro Lett. 2019, 8, 1303-1308.

[0112] The structures of the polymerizable liquid crystal compound molecules synthesized in the above Synthesis Examples 1 to 3 are shown in the following Scheme 1. The number of repeating units of the methylene group in the hydrophobic part is 11, and the number of repeating units (n + 2) of the methylene group in the hydrophilic part is 3, 9, and 12.

[0113] Scheme 1 Compound 1a-1c TIFF0007694934000025.tif43168 Compound 2 TIFF0007694934000026.tif25168

[0114] Compound 2 in the above Scheme 1 is Comparative Molecule 2 and is a compound described in the prior art (Patent Document 3).

[0115] The liquid crystallinity of the synthesized compounds 1a-1c is shown in Table 1. A liquid crystal phase (smectic liquid crystal) having a layered regular structure was formed.

[0116]

Table 1

[0117] The characteristics of the membranes in the examples and comparative examples were evaluated by measuring the inhibition rate of viruses using a composite semipermeable membrane. The virus to be inhibited was bacteriophage Qβ. Bacteriophage Qβ is a non-pathogenic virus that infects Escherichia coli and has a shape close to a sphere with a diameter of 25 nanometers. The concentration of the virus was measured by the plaque method. The virus inhibition ability was 1.0×10 7Feed water at a concentration of (virus rejection rate (LRV)) Virus rejection rate (LRV) = Log 10 (virus concentration in feed water / virus concentration in permeate water) If the virus rejection rate (LRV) is 4, the virus concentration in the permeate water is 1 / 10,000 of the concentration of the feed water. (membrane permeation flux) Membrane permeation flux (m 3 / m 2 / day) = amount of permeate water per day / membrane area

[0118] [Example 1] Molecules used in the preparation of the nanostructured composite semipermeable membrane and examples of water treatment Scheme 1 shows a schematic diagram of polymerizable liquid crystal compounds 1a - 1c having a photocleavable moiety used in the preparation of the nanostructured composite semipermeable membrane and polymerizable liquid crystal 2 having no photocleavage site as a comparative example. Both compounds 1a - 1c and 2 form a smectic phase. According to the procedure described in Patent Document 3, a porous support membrane was laminated with a monomeric liquid crystal, and then the liquid crystal was polymerized to prepare a composite semipermeable membrane for water treatment. Also, for the membrane prepared from compound 1a, by irradiating light containing ultraviolet light to react the photocleavage site and washing the membrane with a hydrophilic solvent such as methanol or water, only the polymer thin film with the hydrophilic groups removed was retained, and nanoholes with an enlarged size were obtained.

[0119] The inhibition rate of bacteriophage Qβ was measured for the fabricated composite semipermeable membrane. Qβ is nearly spherical with a diameter of 25 nm and is small as a virus. It infects Escherichia coli but is non-pathogenic to humans. The virus inhibition ability was determined by subjecting the feed water at a concentration of 1.0×10 7 pfu / mL (pfu: virus concentration unit (plaque forming unit)) to membrane filtration treatment at a temperature of 25 °C and an operating pressure of 0.3 MPa, measuring the water quality of the permeate water and the feed water, and calculating the salt rejection rate and the membrane permeation flux according to the following formula. Virus rejection rate (LRV) = Log 10 (virus concentration in feed water / virus concentration in permeate water) (Virus rejection rate (LRV) = 4 → the virus concentration in the permeate water is 1 / 10000 of the concentration of the feed water) Membrane permeation flux = volume of water permeating through the membrane per unit time (L / hour) / membrane area (m 2 )

[0120] As a result of measuring the salt rejection rate and the membrane permeation flux of the obtained composite semipermeable membrane, the values shown in Table 2 were obtained.

[0121]

Table 2

[0122] In the examples of the present invention, in addition to a high removal rate of LRV = 5.7, a high membrane permeation flux of 50 to 70 L / hour / m 2 is achieved. According to the WHO standard, it is approved with a virus rejection rate of 99.999%, and the examples of the present invention are at a higher level.

[0123] According to the present invention, for the purpose of high virus removal ability and permeation flux, rod-shaped molecules in which a hydrophilic site and a hydrophobic site are bonded at a photocleavable site were developed. The obtained photoreactive molecules exhibited a smectic liquid crystal, which is a liquid crystal phase having a lamellar regular structure. By forming a polymer composite membrane in the liquid crystal state of this molecule, a virus removal membrane showing high water permeability was fabricated.

Claims

1. A liquid crystal thin film obtained by polymerizing a polymerizable liquid crystal compound having a smectic structure, The polymerizable liquid crystal compound has a hydrophobic part, a hydrophilic part, a photocleavable part, and a polymerizable group, and the hydrophobic part and the hydrophilic part are connected by a photocleavable part, The polymerized liquid crystal thin film is obtained by polymerizing at least one compound represented by the general formula (I). (In the general formula (I), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R ２ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH ２ O-; Y is a single bond, an oxygen atom or -CH ２ O-; T is a single bond or a linking site, The linking site is -C(=O)-O- or -O-; PC is a photocleavable site represented by the following formula (7) (In the formula (7), R8 represents a hydrogen atom or one to three arbitrary monovalent substituents that can be substituted on the benzene ring (when two or three substituents are shown, they may be the same or different); * indicates the position where it binds to T; ** indicates the position where it binds to X); P is a photopolymerizable group; n is an integer from 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group, Here, the neutral group is represented by the following formula (6) (In the formula (6), t is an integer from 1 to 6).)

2. The liquid crystal thin film according to claim 1, wherein the photopolymerizable group is a group represented by the following formula (1) or (2). (In formula (1), R ３ａ is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, * indicates the bonding position.) (In formula (2), R ３ｂ is a linear or branched alkyl group having 1 to 8 carbon atoms or a hydrogen atom, * indicates the bonding position.)

3. The liquid crystal thin film according to claim 1 or 2, wherein the cationic group is represented by any one of the following formulas (3) to (5). (In formula (3), R ４ , R ５ and R ６ may be the same or different and are each independently (CH ２ ) ｋ－１ CH ３ , (CF ２ ) ｋ－１ CF ３ , (CH ２ ) ｇ (CF ２ ) ｋ－１ CF ３ and (CH ２ CH ２ O) ｇ CH ３ selected from the group consisting of, and k and g may be the same or different for each R ４ , R ５ and R ６ Here, g is an integer from 1 to 8, and k is an integer from 1 to 8. X － is Cl － , Br － , I － , F － , BF ４ － , N(CN) ２ － , PF ６ － , CF ３SO ３ － or (CF ３ SO ２ ) ２ N － is any of them.) (In formula (4), R ７ is a linear or branched alkyl group having 1 to 6 carbon atoms, X － is as defined in formula (3).) (In formula (5), X － is as defined in formula (3).)

4. The anionic group is -Bz-O － Y ｎ＋ (Bz represents a benzene ring), -SO ３ － Y ｎ＋ , -COO － Y ｎ＋ , -O-CO － =C(CN) ２ ·Y ｎ＋ , or -SO ２ -N － -SO ２ -CF ３ ·Y ｎ＋ (where Y ｎ＋ is a metal ion or an ammonium ion), the liquid crystal thin film according to claim 1 or 2.

5. The connecting site of T is -C(=O)-O-, the liquid crystal thin film according to any one of claims 1 to 4.

6. The compound represented by the general formula (I) is the compound represented by the following formula (Ia), the liquid crystal thin film according to claim 1. (In formula (Ia), Y, P, m, s, L are the same as those defined for the general formula (I).)

7. Having a smectic structure, the liquid crystal thin film according to any one of claims 1 to 6.

8. A liquid crystal thin film in which a polymerizable liquid crystal compound having a smectic structure is polymerized, The polymerizable liquid crystal compound has a hydrophobic part, a hydrophilic part, a photocleavable part, and a polymerizable group, and the hydrophobic part and the hydrophilic part are connected by a photocleavable part, The polymerized liquid crystal thin film has a repeating unit derived from at least one monomer represented by the general formula (I). (In the general formula (I), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R ２ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH ２ O-; Y is a single bond, an oxygen atom or -CH ２ O-; T is a single bond or a linking site, The linking site is -C(=O)-O- or -O-; PC is a photocleavable site represented by the following formula (7), (In the formula (7), R8 represents a hydrogen atom or one to three arbitrary monovalent substituents that can be substituted on the benzene ring (when two or three substituents are shown, they may be the same or different); * indicates the position where it binds to T; ** indicates the position where it binds to X); P is a photopolymerizable group; n is an integer from 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group, Here, the neutral group is represented by the following formula (6) (In the formula (6), t is an integer from 1 to 6).)

9. A liquid crystal thin film having nano-sized pores, which has a structure in which a hydrophilic part and a photo-cleavable site are removed from the polymerized liquid crystal thin film according to any one of claims 1 to 8.

10. A microporous support membrane, and A composite semipermeable membrane comprising the polymerized liquid crystal thin film according to any one of claims 1 to 8.

11. A microporous support membrane, and A composite semipermeable membrane comprising the liquid crystal thin film having nano-sized pores according to claim 9.

12. The composite semipermeable membrane according to claim 10 or 11, which is used for water treatment.

13. A polymerizable liquid crystal compound represented by the following general formula (I). (In general formula (I), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; R ２ is a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group or a methoxy group; X is a single bond, an oxygen atom or -CH ２ O-; Y is a single bond, an oxygen atom or -CH ２ O-; T is a single bond or a linking site, The linking site is -C(=O)-O- or -O-; PC is a photo-cleavable site represented by the following formula (7), (In formula (7), R 8 represents a hydrogen atom or 1 to 3 arbitrary monovalent substituents that can be substituted on the benzene ring (when 2 or 3 substituents are shown, they may be the same or different); * indicates the bonding position with T; ** indicates the bonding position with X); P is a photo-polymerizable group; n is an integer of 1 to 2; m is an integer from 1 to 12; s is an integer from 1 to 12; L is a cationic group, an anionic group or a neutral group, wherein the neutral group is represented by the following formula (6) (in formula (6), t is an integer from 1 to 6).)

14. A polymerizable composition containing the polymerizable liquid crystal compound according to claim 13.

15. A polymer obtained by polymerizing the polymerizable liquid crystal compound according to claim 13 or the polymerizable composition according to claim 14.

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