Membrane for removing metal species from amine

Abstract

To provide a ligand modification filter material useful for removing metal pollutants from a fluid.SOLUTION: A membrane including a polymer added with a ligand and where the ligand includes at least one guanidine part is provided. The ligand desirably includes at least one guanidine part having the structure and the ligand including at least one guanidine part is desirably polyguanidine.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The following disclosure relates to ligand-modified articles such as filter membranes, and methods of using articles for removing metals from liquid compositions.

Background Art

[0002] Filters are used to remove unwanted materials from the flow of useful fluids and are an important feature in a wide variety of industrial technologies. Fluids to be treated to remove unwanted materials include water, liquid industrial solvents and process fluids, industrial gases used in manufacturing or processing, and liquids having medical or pharmaceutical applications. Unwanted materials removed from the fluid include impurities and contaminants such as particles, microorganisms, and dissolved chemical species. Specific examples of filter applications include use with liquid materials for semiconductor and microelectronic device manufacturing.

[0003] Filters can remove unwanted materials in a variety of different ways, such as by size exclusion or by chemical and / or physical interactions with materials. Some filters are defined by a structural material that provides a porous structure to the filter, and the filter can capture particles of a size that cannot pass through the pores. Some filters are defined by the ability of the structural material of the filter, or a chemical material associated with the structural material, to associate and interact with the materials passing through the filter. For example, the chemical characteristics of the filter enable association with unwanted materials from the flow passing over the filter and can capture those unwanted materials by ionic, coordination, chelation, or hydrogen bonding interactions. Some filters can utilize both size exclusion and chemical interaction characteristics to remove materials from the filtered flow.

[0004] In some cases, to perform a filtering function, the filter includes a filter membrane that serves to remove unwanted materials from the fluid passing through. The filter membrane may, if necessary, be in the form of a flat sheet, may be wound up (e.g., in a spiral), may be flat, may be pleated, or may be disk-shaped. Alternatively, the filter membrane may be in the form of hollow fibers. The filter membrane is housed within or otherwise supported within a housing such that the fluid being filtered enters through a filter inlet and passes through the filter membrane before passing through a filter outlet.

[0005] Removing ionic materials such as dissolved anions or cations from a solution is important in many industries such as the microelectronics industry where ionic contaminants and very low concentrations of particles can adversely affect the quality and performance of microprocessors and memory devices. In particular, it may be desirable to remove metal-containing materials such as metal ions from the liquid compositions used in device manufacturing. Metal-containing materials can be found in different types of liquids used in microelectronics manufacturing.

[0006] There remain various unresolved technical challenges for removing metal-containing materials from fluids. In particular, there is a need for an improved methodology for removing metal ions such as Fe 2+ and Fe 3+ from fluids containing amines and amino alcohols. Aqueous amines are used in the manufacture of semiconductors. For example, hydroxylamine is often a component of photoresist strippers that remove photoresist after lithography. Reducing metal ion contaminants across the semiconductor supply chain is becoming increasingly important in efforts to reduce defects and improve yields. Metal ion reduction is important for materials that come into direct contact with the wafer surface such as hydroxylamine and ammonium hydroxide. Conventional methods of metal ion reduction such as ion exchange filtration do not sufficiently reduce metal ions from aqueous amines. Hydroxylamine is particularly problematic because it forms complex structures with transition metals such as iron.

Summary of the Invention

[0007] The present disclosure provides various embodiments of the invention directed to the removal of metal contaminants from fluids and ligand-modified filter materials useful for practicing such methods. The filters and methods of the present disclosure are particularly effective at removing metals from liquid compositions. The filtered liquid compositions with significantly reduced amounts of metals, such as liquids used for removing photoresist or liquids used in etching, can be used in microelectronic manufacturing processes. Ligand-modified filters, such as ligand-modified porous membranes, can be configured for use in microelectronic manufacturing systems, which can be utilized in the system as a point-of-use metal removal mechanism for the liquid entering the system.

[0008] Accordingly, one aspect of the present disclosure is a polymer to which a ligand is added, the ligand having the structure: TIFF2025090603000002.tif42170(wherein Q is selected from -CH2-, -N(R)- or CH(N)-, and R is a C1-C 20 hydrocarbyl group) and includes a membrane comprising a polymer containing at least one moiety represented by.

[0009] Another aspect of the present disclosure is a method for removing one or more metals or metal ions from a liquid composition. In certain embodiments, the liquid composition comprises an amine. As used herein, the term "amine" is in no way limited and can be selected, by way of example, from primary, secondary, and tertiary amines, and such amines substituted with one or more alkyl groups, hydroxyl groups, or other functional groups, and such amines combined with water, i.e., aqueous amines.

[0010] The present disclosure may be more fully understood in view of the following description of various exemplary embodiments in connection with the accompanying drawings.

Brief Description of the Drawings

[0011]

Figure 1

[0012] The present disclosure can accept various changes and alternative forms, and the details are shown in the drawings by way of example and will be described in detail. However, it should be understood that the present disclosure is not intended to be limited to the specific exemplary embodiments described. On the contrary, the intention is to cover all changes, equivalents, and alternatives that fall within the spirit and scope of the present disclosure.

[0013] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise.

[0014] The term "about" generally refers to a range of numbers that are considered to be equivalent (e.g., having the same function or result) to the recited value. In many cases, the term "about" can include numbers rounded to the nearest significant digit.

[0015] Numerical ranges expressed using endpoints include all numbers within that range (e.g., 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0016] The following detailed description should be read with reference to the drawings in which like elements in different drawings are numbered the same. The detailed description and the drawings are not necessarily to scale and illustrate exemplary embodiments and are not intended to limit the scope of the invention. The illustrated exemplary embodiments are intended only by way of example. Unless the contrary is clearly stated, selected features of any exemplary embodiment may be incorporated into additional embodiments.

[0017] A first aspect of the present disclosure is a polymer to which a ligand is attached, the ligand having the structure: TIFF2025090603000003.tif42170(wherein Q is selected from -CH2-, -N(R)- or -CH(N)-, and R is a C1-C 20 hydrocarbyl group) and includes a polymer containing at least one moiety represented by.

[0018] In one embodiment, the term "C1-C 20 hydrocarbyl" refers to a saturated or unsaturated straight-chain, branched or cyclic hydrocarbon having 1 to 20 carbon atoms and optionally substituted by one or more heteroatoms and functional groups. Exemplary functional groups include halo, nitro, cyano, amino, alkoxy or alkanoyloxy. The above wavy line indicates either the point of attachment of the moiety to the membrane, or another group of atoms forming the remainder of the ligand. TIFF2025090603000004.tif7170.

[0019] In certain embodiments, the ligand includes at least one guanidine moiety. In other embodiments, the ligand includes at least one amidine moiety. In other embodiments, the ligand has the structure: TIFF2025090603000005.tif39170 and includes at least one moiety of.

[0020] In certain embodiments, the ligand has the structure: TIFF2025090603000006.tif93170(wherein each R is independently selected from hydrogen, C1-C4 alkyl, cyclohexyl and phenyl) and includes a guanidine moiety bonded via a benzyl group.

[0021] In certain embodiments, the ligand includes a compound having the structure: TIFF2025090603000007.tif91170.

[0022] In other embodiments, the ligand has a guanidine moiety having structure (IV): TIFF2025090603000008.tif62170.

[0023] In another embodiment, the ligand has an amidine moiety: TIFF2025090603000009.tif42170.

[0024] In one embodiment, the ligand has a structure: TIFF2025090603000010.tif194170TIFF2025090603000011.tif97170 and includes a moiety selected from the compounds.

[0025] In this embodiment, it will be understood that in some of the above structures, the point of attachment is a quaternary nitrogen atom. The counterion (not shown) is generated from the starting material that reacts with the ring system and is selected from halogens.

[0026] In another embodiment, the ligand has a structure: TIFF2025090603000012.tif162170 and is selected therefrom.

[0027] In one embodiment, the ligand is selected from polyguanidines. Examples of polyguanidines include the following. TIFF2025090603000013.tif208170

[0028] In this embodiment, the ligand can be bound or attached to the polymer membrane via one of the free amine groups that is reactive with a group on the polymer surface or with another material present on the surface of the polymer, thereby forming a coating containing the ligand.

[0029] In one embodiment, the ligand has a structure: TIFF2025090603000014.tif71170.

[0030] In one embodiment, the filter membrane is in the form of a porous membrane.

[0031] The filter material to which the ligand is bound can be made of any suitable material or combination of materials. Exemplary filter materials can include one or more of polymers, metals, ceramics, or natural materials. Further, in some aspects, the filter material can have chemical properties suitable for binding to the ligand. Alternatively, the surface of the filter material can be modified to be chemically reactive with the ligand or its derivative. The ligand described above may be attached or added to the underlying porous polymer membrane.

[0032] "Filter" refers to an article having a structure that includes a filter membrane. For example, the filter can be in any useful form for a filtration process, such as a porous membrane, and the filter is made from one or more filter materials such as polymers including synthetic and natural polymers, alloys, natural materials, ceramics, and metal-containing materials such as carbon fibers. In some embodiments, the ligand can covalently bond to the filter membrane.

[0033] The filter can be in any desired form suitable for filter ring applications. The material forming the filter can be a structural component of the filter itself, providing the desired structure to the filter. The filter can be porous or non-porous and can have any desired shape or configuration. The filter itself can be an integral article such as a non-woven porous filter membrane.

[0034] In some embodiments, the filter material is formed from a polymer material, a mixture of different polymer materials, or a polymer material and a non-polymer material. The polymer materials forming the filter can be crosslinked together to provide a filter structure having the desired integrity.

[0035] Polymer materials that can be used to form the membranes (i.e., filter membranes) of the present disclosure include hydrophobic polymers. In some embodiments, the membrane comprises a polyolefin or a halogenated polymer. Exemplary polyolefins include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene (PB), polyisobutylene (PIB), and copolymers of two or more of ethylene, propylene, and butylene. In further specific embodiments, the membrane comprises ultra-high molecular weight polyethylene (UPE). UPE filter materials such as UPE membranes are typically formed from resins having a molecular weight (weight average molecular weight) exceeding about 1×10 6 ~9×10 6 Daltons (Da), or in the range of about 1×10 6 ~9×10 6 Da, such as exceeding about 1×10 6 Da. Crosslinking between polyolefin polymers such as polyethylene can be facilitated by the use of heat or crosslinking chemicals such as peroxides (e.g., dicumyl peroxide or di-tert-butyl peroxide), silanes (e.g., trimethoxyvinylsilane), or azoester compounds (e.g., 2,2'-azo-bis(2-acetoxy-propane)). Exemplary halogenated polymers include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), fluorinated ethylene polymer (FEP), polyhexafluoropropylene, and polyvinylidene fluoride (PVDF).

[0036] In other embodiments, the membrane comprises a polymer selected from polyamide, polyimide, polysulfone, polyethersulfone, polyarylsulfone polyamide, polyacrylate, polyester, nylon, cellulose, cellulose ester, polycarbonate, or combinations thereof.

[0037] The ligand of the above structure (II) can be synthesized by the method described in U.S. Patent No. 5,767,229, which is incorporated herein by reference. The ligand of the above structure (III) can be synthesized, for example, as shown in Example 7 below. The ligands of the above structures (V, VI, VII) can be synthesized by reacting the corresponding cyclic amidines (tricyclic 2,4-diaminovinylamidine and pentacyclic amidine, Angewandte Chemie-International Edition, 26, 1164-1165. Angewandte Chemie-International Edition, 26, 1165-1167. Nachrichten aus Chemie Technik und Laboratorium, 38, 1214-1226)) with glycidyl vinyl ether or 4-chloromethylstyrene.

[0038] The ligands of the present disclosure can be bound or added to the underlying porous membrane by a number of methods. See, for example, the method described in U.S. Patent Publication No. 2020-0254398, which is incorporated herein by reference.

[0039] Generally, the ligands of the present disclosure can be attached to a polymer membrane by binding to a reactive crosslinking coating. For example, a filter material can be coated with a solution of an amine-reactive polymer such as poly(vinylbenzyl chloride), poly(epichlorohydrin), or an epoxy resin. The coated and dried membrane can then be crosslinked by reacting it with a diamine, polyamine, or any other polyfunctional reactive crosslinking agent, and the remaining reactive sites are used for the attachment of the desired ligand. A similar method can be used to perform crosslinking and ligand attachment simultaneously, where the ligand itself functions as a crosslinking agent. In one embodiment, the desired ligand is first reacted with a halogenated compound having olefinic unsaturation, such as 4-(chloromethyl)styrene. Then, the ligand having a vinylbenzyl group is applied as a solution to a porous membrane together with another reactive compound that functions as a crosslinking agent, such as N,N'-methylenebis(acrylamide), and then subjected to UV irradiation in the presence of a suitable photoinitiator such as Ciba® IRGACURE® 2959 to provide a crosslinked coating on the porous membrane, the coating having the desired ligand covalently incorporated therein. Other examples of crosslinking agents include triethylene glycol dimethacrylate, triethylene glycol diacrylate, ethylene glycol divinyl ether, and the like. In another embodiment, the ligands of the present disclosure can be grafted onto a membrane using the methods taught in U.S. Patent Publication No. 2020-0254398 and International Publication No. 2017 / 205722, which are incorporated herein by reference. This grafting can be achieved by UV irradiation of the polymer membrane in the presence of an unsaturated monomer containing a photoinitiator and the ligand of the present disclosure. In another embodiment, the grafting may utilize electron beam or gamma ray irradiation.

[0040] The concentration of the ligand can be sufficient to enable the ligand to be immobilized on the surface of the filter material at a desired density. The ligand solution can be applied to the surface of the filter material by any useful technique such as spraying, immersion, dipping, etc. of the filter material solution. Desirably, the entire surface of the filter, such as all the inner surfaces of the porous filter membrane, can be brought into contact with the solution. Optionally, the application step can include manipulation of the filter material, for example, by rolling or squeezing the porous filter medium to wet all the surfaces of the porous filter.

[0041] In various examples of the methods and apparatuses herein, the filter includes a porous filter membrane having a ligand added to the polymeric material forming the membrane. As used herein, a "porous filter membrane" is a porous solid that includes porous (e.g., microporous) interconnected passages extending from one surface of the membrane to the opposite surface of the membrane. The passages generally provide tortuous tunnels or paths through which the liquid to be filtered must pass. Metal species small enough to pass through the pores of the membrane can be captured on the membrane by interaction with the ligand, such as by chelation interactions between the ligand and the metal. This is referred to as a "non-sieving filtration mechanism".

[0042] The filter can also function to prevent any particles (e.g., metal-containing particles) present in the liquid, which are larger than the pores, from entering the microporous membrane, or can function to capture particles within the pores of the microporous membrane (i.e., remove the particles by a sieving-type filtration mechanism). The liquid to be treated can pass through the membrane, resulting in a reduced inflow of metal, such as a reduction in the amount of ionic metal species, a reduction in the amount of metal-containing fine particles, or both.

[0043] Accordingly, the porous polymer membrane to which the ligand is bound can remove metals and metal ion contaminants in the solution passing through the membrane, as well as any material that is too large to pass through the pores of the membrane.

[0044] The porous membrane of the present disclosure can be described with reference to one or more properties of the membrane. The exemplary porous polymer filter membranes described herein can be characterized by physical characteristics including pore size, bubble point, and porosity. For example, the membrane can be described in terms of the bubble point, which is commonly used to reflect the pore size.

[0045] The bubble point method is based on the premise that for a specific fluid with a certain wetting and a specific pore size, the pressure required to push air bubbles through the pores is inversely proportional to the size of the pores. The diameter of the capillary can be calculated by determining the pressure required to extrude water from the capillary. The porosity measurement bubble point test method measures the pressure required to push air through the wet pores of the membrane. Thus, the bubble point test is a well-known method for determining the pore size of a membrane. To determine the bubble point of a porous material, a sample of the porous material is immersed and wetted in ethoxy-nonafluorobutane HFE 7200 (available from 3M) at a temperature of 20 - 25 °C (e.g., 22 °C). Gas pressure is applied to one side of the sample using compressed air, and the gas pressure is gradually increased. The differential pressure at which the wet flow is equal to half of the dry flow (the flow that does not wet the solvent) is called the bubble point.

[0046] In certain aspects of the present disclosure, the porous polymer membrane can have a bubble point in the range of about 2 psi to about 400 psi, about 4 psi to about 200 psi, or about 4 psi to about 160 psi at a temperature of 22 °C when using ethoxy-nonafluorobutane (HFE - 7200) as the wetting solvent.

[0047] Alternatively, the pore size can be measured by known techniques such as mercury porosimetry (MP), scanning electron microscopy (SEM), liquid displacement porosimetry (LLDP), or atomic force microscopy (AFM).

[0048] The porous polymer filter membrane can have any pore size that enables it to function effectively as a filter membrane. The pore size can be correlated with the determination of the bubble point. In some embodiments, the porous membrane can have an average pore size in the range of about 0.001 micron to about 5 or 10 microns, such as 0.01 to 0.8 microns. The average pore size can be selected based on one or more factors including fluid flow rate, pressure, consideration of pressure drop, consideration of viscosity, impurities in the liquid being treated (such as the amount of metal impurities), and any particle size of the impurities.

[0049] Furthermore, the present disclosure contemplates the use of polymer membranes having a substantially uniform pore size resulting from a higher degree of pore symmetry, as well as membranes having a non-uniform pore size (variable pore size) resulting from pore asymmetry. The pores can be isotropic or anisotropic, with or without a skin, symmetric or asymmetric, and any combination thereof.

[0050] The described porous polymer filter layer can have any porosity that enables the porous polymer filter layer to be effective as described herein. An exemplary porous polymer filter layer can have a relatively high porosity, such as at least 60, 70 or 80% porosity. As used herein, and in the technical field of porous bodies, the "porosity" of a porous body (sometimes referred to as the void fraction) is a measure of the void (i.e., "empty") space within the body as a percentage of the total volume of the body, and is calculated as the ratio of the volume of the voids in the body to the total volume of the body. A body with 0% porosity is completely solid.

[0051] The filter membrane of the present invention can be useful in any type of industrial process that requires a high-purity amine-containing liquid material as an input. Non-limiting examples of such processes include processes for preparing microelectronic or semiconductor devices, and a specific example thereof is a method of filtering a liquid process material used in semiconductor photolithography. The filter of the present disclosure can remove metal ions and metal-containing fine particles from a process liquid or solvent used for preparing microelectronics or semiconductors, and can also remove other non-metal fine particle materials by the sieving action of the membrane. In particular, the filter of the present disclosure is particularly effective in removing iron ions from amine-containing liquids.

[0052] The porous membrane of the present disclosure can be in any desired geometric configuration suitable for use in a system for reducing metal or metal ion contamination in a fluid stream. For example, the porous membrane described herein can have any one or more of a variety of geometric configurations or forms. For example, the porous membrane can have any one or more shapes selected from circular, semi-circular, elliptical, semi-elliptical, or polygons such as square, rectangular, hexagonal, or octagonal. The porous membrane can be in the form of, among other things, flat sheets, corrugated sheets, pleated sheets, and hollow fibers.

[0053] The described porous polymeric filter membrane can be in the form of a sheet or hollow fiber having any useful thickness, for example in the range of 20 to 400 microns, for example 40 or 80 to 100 or 200 microns.

[0054] The porous membrane of the present disclosure can be associated with a support structure, a housing, or both. For example, the coated porous membrane can be supported by a frame, bracket, clip, web, net, cage, etc. In some configurations, at least a portion of the support structure can be the housing, as described herein. Alternatively, the porous membrane is unsupported.

[0055] The porous membrane can exist as part of a filter assembly that includes a housing. For example, the housing is fluidly sealed (separate from the inlet and outlet ports), can hold a certain amount of liquid, and is configured to allow the liquid to pass through the membrane. The housing can be used to form a larger filter structure, such as a filter assembly (single or multi-layer) or a filter cartridge used in a filtration system. The filtration system places the filter membrane, for example, as part of a filter assembly or as part of a filter cartridge, within a filter housing to expose the filter membrane to the flow path of the chemical solution, passes at least a portion of the flow of the chemical solution through the filter membrane, and the filter membrane removes a certain amount of impurities or contaminants from the liquid chemical. The structure of the filter assembly or filter cartridge can include one or more various additional materials and structures that support the composite filter membrane within the filter assembly or filter cartridge and allow fluid to flow from the filter inlet through the filter material (e.g., the filter membrane) and through the filter outlet. The filter membrane supported by the filter assembly or filter cartridge can be of any useful shape, such as a pleated cylinder, a cylindrical pad, a (flat) cylindrical sheet without one or more pleats, a pleated sheet, etc.

[0056] One embodiment of the present disclosure includes a filter device and a method for removing metal contaminants from a liquid, where the liquid passes through a porous polymer membrane to which ligands are attached. As shown in FIG. 1, the present disclosure provides a filter 100 that includes a porous polymer membrane 102. The porous polymer membrane 102 includes ligands attached to the surface of the membrane. The filter 100 can have a housing 104 that provides structure to the filter 100 and fluidly seals the interior of the filter. The housing 104 can be of any shape and size, such as cylindrical, polygonal, etc.

[0057] A portion of the filter can include an inlet port 106 for receiving a metal / metal ion-containing fluid composition to be filtered. The inlet port 106 can be configured to be connected to a fluid supply line. Thus, the inlet port 106 can include valves, gaskets, etc. (not shown) to facilitate connection to a fluid source. The metal / metal ion-containing fluid composition to be filtered flows through the inlet port 106 in the direction indicated by arrow 116 and can flow into the headspace 114 of the filter 100 as defined by the input-facing surface 124 of the porous polymer membrane 102, the inner surface of the housing 104, and the inlet port 106. In an embodiment, the filter can be configured to have a volume such that the headspace is a desired percentage of the total internal volume of the filter.

[0058] The inner portion of the filter can include a porous membrane in any suitable arrangement or array, and FIG. 1 shows a porous polymer membrane 102 having a disk-like structure (showing a cross-sectional view). The side surface 122 of the porous polymer membrane 102, such as the outer periphery of the membrane, can contact the inner surface of the housing 104. The porous polymer membrane 102 can also have an input-facing surface 124 that first contacts the metal / metal ion-containing fluid and an output-facing surface 126 from which the treated fluid with a reduced amount of metal / metal ions flows. Aspects of the filter can optionally be described in terms of the range of the ratio of the surface area of the input-facing surface 124 to the volume of the porous polymer membrane 102, or the ratio of the surface area to the thickness of the filter.

[0059] Filter 100 can also include one or more features that support the porous polymer membrane 102 within the filter. Any arrangement can be used to support the filter, including one or more discrete structural features such as frames, frames, brackets, clips, webs, nets, and cages, or a material such as an adhesive can be used to support the membrane. A combination of an adhesive and a structural support mechanism can be used. In one embodiment, referring to FIG. 1, the filter includes a frame having frame portions 110 and 112, where frame portion 110 is in contact with the inner surface of housing 104 attached to portion 112. Portion 112 can be in contact with the output-facing surface 124 of the porous polymer membrane 102 and can support the membrane during filtration. Frame portion 112 can have a lattice structure that provides structural support to the polymeric porous membrane under increased fluid pressure while allowing the filtered liquid to freely pass into the backspace 120 of the filter.

[0060] In use, liquid enters the filter through inlet port 106 in the direction indicated by arrow 116 and then fills the headspace 114 within filter 100. A fluid pressure sufficient to cause the fluid to pass through the porous polymer membrane at a desired flow rate is applied.

[0061] Exemplary flow rates of the porous membrane range from about 0.1 L / min to about 40 L / min, or from about 5 L / min to about 20 L / min. Alternatively, the flow rate of the porous membrane can be expressed in terms of the amount of liquid flowing per unit area of the filter per unit time (e.g., Liter / m 2 / h = LMH), such as about 100 LMH / bar to about 30,000 LMH / bar, more preferably about 5,000 LMH / bar to about 15,000 LMH / bar.

[0062] In some embodiments, the filters of the present disclosure include a composite membrane array. For example, a filter having a composite membrane can include two or more filter materials such as two or more filter articles. For example, a filter can include a first porous polymer membrane that includes one of the ligands and a second filter material that does not include the ligand present in the first porous polymer membrane (i.e., a different ligand or some other ligand) or is otherwise different from the first porous polymer membrane in some way. The second filter material can also be in the form of a porous membrane or can be different, such as having a non-porous form. The second filter material can be made of the same or a different polymer material as the first membrane and can be either modified, such as being modified with a ligand that is not present in the first membrane (e.g., a ligand), or not modified.

[0063] In some embodiments, the filter includes a first porous polymer membrane that includes a ligand and a second porous polymer membrane that does not include the ligand or a different ligand. In certain embodiments, the first and second porous polymer membranes are composed of the same or similar polymer materials and have the same or similar pore sizes. In other embodiments, the first and second porous polymer membranes are composed of different polymer materials and / or have different pore sizes.

[0064] The filters of the present disclosure as described can be useful for filtering a liquid to remove undesirable metal-containing materials (e.g., contaminants or impurities) from the liquid and producing a high-purity liquid that can be used as a material in an industrial process. In particular, the porous polymer filter membrane can be useful for removing dissolved and / or suspended metal-containing contaminants from the liquid flowing through the membrane using a combination of a metal ion sieving mechanism and ligand binding. That is, due to the size limitation according to the pore size, larger metal-containing particles can be captured by the filter, and metal ions that would otherwise pass through the pores are captured by interaction with the ligands immobilized on the membrane.

[0065] Filter materials containing ligands can be used to remove metals and metal ions from fluids having levels of these materials that are too high for a desired process.

[0066] Exemplary metals that can be removed from a fluid using the ligand-modified filter materials of the present disclosure include alkali metals including the following chemical elements of Group 1 of the periodic table: lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). Other exemplary metals that can be removed from a fluid using the ligand-modified filter materials of the present disclosure include alkaline earth metals that are chemical elements of Group 2 of the periodic table: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Other exemplary metals that can be removed from a fluid using the ligand-modified filter materials of the present disclosure include transition metals that are elements in the d-block of the periodic table including Groups 3-12 of the periodic table, including, but not limited to, transition metals such as titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), molybdenum (Mo), ruthenium (Ru), palladium (Pb), silver (Au), cadmium (Cd), tungsten (W), and mercury (Hg). Other exemplary metals that can be removed from a fluid using the ligand-modified filter materials of the present disclosure include post-transition metals (Groups 13-15) including aluminum (Al), gallium (Ga), indium (In), tin (Sn), thallium (Tl), lead (Pb), and bismuth (Bi). In one embodiment, the ligand-modified filter of the present disclosure preferentially removes substantially all of the iron and zinc from such a solution. In one embodiment, the ligand-modified filter material of the present disclosure removes substantially all of the iron from such a solution, for example, to less than about 1 ppb (parts per billion).

[0067] Metal contaminants can refer to neutral, negatively charged, or positively charged metal species and combinations thereof that can exist in an equilibrium state. Metals can be present in a liquid in the form of dissolved ions, suspended charged particles, colloids, or other aggregates, and any of these metal forms can be removed from a fluid using the ligand-modified filter materials of the present disclosure. Some metal ions, such as Fe and Al, can exist as oxides in water. These ions can form amphoteric colloid particles or complexes. Under basic conditions, some of the metal ions can exist as hydroxides, oxides, oxyhydroxides, and other anions, or any combination thereof. In some fluids, the metal ions are amphoteric and can form species that contain one or more of these groups, which can exist as cationic or anionic complexes depending on the conditions of the fluid (pH, temperature, ionic strength).

[0068] Metal ion impurities in various fluids can be detected using ion chromatography. Removal of metal materials from fluids treated by the filters of the present disclosure can also be determined using inductively coupled plasma mass spectrometry (ICP-MS).

[0069] As described above, in one embodiment, the liquid composition contains an amine. As used herein, the term "amine" is not limited in any way and generally refers to any compound of the formula TIFF2025090603000015.tif30170 including the portion thereof, and can be selected from, for example, primary, secondary, and tertiary amines, and such amines substituted with one or more hydroxyl groups, alkyl groups, or other functional groups. Examples include the following. Hydroxylamine Ethanolamine Triethanolamine Diethylenetriamine Methylamine Ethylamine Trimethylamine Triethylamine 3 - Diethylaminopropylamine Pyrrole 1,2 - Diaminopropane Pyrrolidine Anisole Aniline N,N - Dimethylaniline 4 - Nitroanisole 3 - Nitroanisole 4 - Trifluoromethylaniline Dopamine Epinephrine Norepinephrine n - Butylamine sec - Butylamine t - Butylamine N - Methyldiethanolamine N - tert - Butyldiethanolamine 2 - Dimethylaminoethanol 2 - (Diethylamino)ethanol 2 - (Dibutylamino)ethanol 1 - [2 - (Diethylamino)ethoxy]ethanol 6 - Dimethylamino - 1 - hexanol Diisopropylamine 2 - (Diethylamino)-1,2 - propanediol 3 - Dimethacrino - 1 - propanol 3 - Diethylamino - 1 - propanol N - tert - Butyldiethanolamine (2 - Methylbutyl)amine Tris(2 - ethylhexyl)amine 4 - Pentin - 1 - amine 1,4 - Benzodioxan - 6 - amine (3 - Methylphenyl)amine Allylamine Cyclohexylamine (3 - Butoxyphenyl)amine 4,5,6 - Trimethylpyrimidin - 2 - amine 1-Benzyl-1H-pyrazol-3-amine 1-Ethyl-1H-imidazol-3-amine Diallylamine 1-Isobutyl-1H-benzimidazol-2-amine 1-Propyl-1H-tetrazol-5-amine (1-Cyclopropylpropyl)amine (2-Cycloheptylethenyl)amine (2-Cyclooctylethyl)amine (3-Cyclopentylpropyl)amine 1,2-Benzisoxazol-6-amine 1,5-Naphthyridin-3-amine 1,6-Naphthyridin-2-amine 1-Methyl-1H-benzimidazol-6-amine 1-Methyl-1H-pyrazol-4-amine 2,4,6-Trifluorobenzylamine 2,4,6-Trimethylpyridin-3-amine 2-Chlorobiphenyl-4-amine 2-Ethylcyclopropan-1-amine

[0070] The filter membranes of this specification can be useful in any type of industrial process that requires a high-purity liquid material as an input. Non-limiting examples of such processes include processes for preparing microelectronic or semiconductor devices, processes for preparing pharmaceutical compositions, and diagnostic (e.g., medical diagnostic) compositions and methods. The methods and filters of the present disclosure can be used in any of these areas.

[0071] Specifically, a method of filtering liquid process materials used in semiconductor photolithography can be mentioned. Examples of contaminants present in the process liquid or used to prepare microelectronic or semiconductor devices can include metal ions dissolved in the liquid, solid microparticles suspended in the liquid, and gelled or coagulated materials present in the liquid (e.g., generated during photolithography). In embodiments, the methods and filters of the present disclosure are used to provide a purified low-metal-containing liquid composition for front-end cleaning tools used to create the foundation for integrated circuits. For example, the filters of the present disclosure can be used to purify cleaning agents and etching agents, minimize product contamination, and improve process efficiency (such as etching rate). In a chemical mechanical polishing process, water is used in addition to reagents and polishing particles.

Example

[0072] Example 1 - Cleaning of Porous Polymer Resin The following examples demonstrate a method used to clean porous polymer resins for use in removing trace metals from amines and aqueous amines.

[0073] First, 50 g of each porous polymer resin was weighed and placed into a clean 1-liter PTFE bottle (Savillex). The resin was wetted with 500 mL of IPA (isopropanol Gigabit® , KMG) and gently stirred for 1 hour. After 1 hour, the resin was allowed to settle and the IPA was decanted. Next, the resin was exposed to a 500 mL mixture of 70% IPA / 10% HCl (hydrochloric acid 37% Gigabit® , KMG) and gently stirred for 1 hour. After 1 hour, the resin was allowed to settle and the 70% IPA / 10% HCl was decanted. Next, the resin was washed and exchanged several times with deionized water (DIW), and the DIW was decanted. Next, the resin was exchanged with 500 mL of 2% NH4OH (ammonium hydroxide 29% Cleanroom® MB, KMG) and gently stirred for 1 hour. Next, the resin was washed and exchanged several times with DIW, and the DIW was decanted. Next, the resin was exposed to 500 mL of 10% HCl and gently stirred for 16 hours. After 16 hours, the resin was allowed to settle and the 10% HCl was decanted. Finally, after the resin was exchanged several times with DIW, it was exchanged several times with IPA and placed in a 70 °C convection oven until dry. The washed and dried resin was placed in a clean PTFE wide-mouth bottle until use.

[0074] Example 2 - Measurement of Metal Species Reduction in 25% Hydroxylamine Using a Porous Polymer Resin Containing 1,5,7-Triazabicyclo[4,4,0]dec-5-ene Ligand by Static Immersion Experiment The following example demonstrates the method used to measure the ability of a porous polymer resin containing 1,5,7-triazabicyclo[4,4,0]dec-5-ene (TBD) to reduce the metal concentration in 25% hydroxylamine under static immersion conditions. The results demonstrate that the resin with TBD is effective in reducing the metal species in the solution after contact with the resin.

[0075] The crosslinked poly(styrene-co-divinylbenzene) resin (Biotage® PS-TBD, Biotage) conjugated with TBD was washed using the same method as in Example 1. A 25% hydroxylamine solution containing Fe was obtained. Next, 0.2 g of the washed and dried resin was measured and placed into a clean 25 mL PTFE wide-mouth bottle (Savillex). Next, 20 mL of the 25% hydroxylamine solution was added to the PTFE wide-mouth bottle containing the washed resin. The wide-mouth bottle was capped and rotated for 16 hours. After 16 hours, the resin was allowed to settle and the liquid was decanted into vials for analysis. The metal concentration of each liquid sample was measured by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). To ensure reproducibility, the entire experiment was conducted in duplicate. This experiment demonstrated that the resin crosslinked poly(styrene-co-divinylbenzene) resin conjugated with TBD was able to reduce metal species including >96% reduction of Fe, but was also effective in removing more than 50% of Na, K, Mg, Mn, Cr, Al, Ni, Zn, Ba, and Pb from the 25% hydroxylamine solution.

[0076] Example 3 - Preparation of Reactive 1,5,7-Triazabicyclo[4,4,0]dec-5-ene Vinyl Monomer The following example shows a method for preparing a solution containing a reactive vinyl monomer having a 1,5,7-triazabicyclo[4,4,0]dec-5-ene moiety.

[0077] In a wide-mouth bottle, a solution was prepared by dissolving 4.2 g of 1,5,7-triazabicyclo[4,4,0]dec-5-ene (CAS#5807-14-7, Sigma) in 17.5 g of deionized water. Another solution was prepared by dissolving 4-(chloromethyl)styrene (CAS number 1592-20-7, TCI) in 43.7 g of dimethylformamide. The 4-(chloromethyl)styrene / dimethylformamide was added to the wide-mouth bottle containing 1,5,7-triazabicyclo[4,4,0]dec-5-ene / deionized water, and the resulting mixture in the wide-mouth bottle was tightly capped and the solution was rotated at 80 °C for 6 hours. After 6 hours, the wide-mouth bottle containing the resulting solution was removed from the heat and cooled to room temperature.

[0078] Example 4 - Preparation of a UPE Membrane with a Stable Surface Coating Containing (1,5,7-Triazabicyclo[4,4,0]dec-5-ene) This example demonstrates the surface modification of a UPE membrane classified into a 50 nm pore size grade with a stable surface coating containing a (1,5,7-triazabicyclo[4,4,0]dec-5-ene) ligand.

[0079] The surface modification was achieved by applying a photoinitiated crosslinking coating incorporating the vinylbenzyl-(1,5,7-triazabicyclo[4,4,0]dec-5-ene) monomer prepared in Example 3. First, a monomer solution was prepared by adding 7% vinylbenzyl-(1,5,7-triazabicyclo[4,4,0]dec-5-ene), 2% methylenebisacrylamide, 0.4% Irgacure 2959, 10% deionized water, and 80.6% isopropanol by weight. Next, an unmodified 50 nm UPE membrane was cut into 47 mm diameter coupons and then immersed in the monomer solution. Next, the coupons were removed from the monomer solution and immediately placed between two transparent polyethylene sheets, and excess liquid was nipped using a rubber roller. Then, the membrane coupons that had absorbed the monomer were removed from the polyethylene sheets and air-dried for 15 minutes. After 15 minutes of drying, the dried coupons were wetted with Galden® HT 135 (Solvay) and immediately placed between two polyethylene sheets and passed through a Fusion Systems broadband UV lamp at a speed of 6 feet per minute. The UV-cured membrane coupons were removed from the polyethylene sheets, dried, washed twice with isopropanol, water, and methanol, and then dried.

[0080] Example 5 - Measurement of Fe Reduction in 2 and 14% Ammonium Hydroxide by a UPE Membrane Containing a (1,5,7-Triazabicyclo[4,4,0]dec-5-ene) Ligand Using a Static Immersion Experiment The following examples show a method used to measure the ability of a UPE membrane, divided into a 50 nm pore size grade and containing (1,5,7-triazabicyclo[4,4,0]dec-5-ene), to reduce Fe concentrations in 2% and 14% NH4OH under static immersion conditions. The results demonstrate that the UPE membrane with (1,5,7-triazabicyclo[4,4,0]dec-5-ene) is effective in removing Fe from 2% and 14% NH4OH after contact with the membrane.

[0081] First, a UPE membrane divided into a 50 nm pore size grade and containing (1,5,7-triazabicyclo[4,4,0]dec-5-ene) was prepared using the same method as in Example 4 and then cut into 47 mm coupons. Next, the membrane coupons were washed using the same method as in Example 1. Next, 2500 ppt of Fe at the target concentration was added to 2% and 14% NH4OH solutions using PlasmaCAL Single Element Calibration Standards, SCP SCIENCE. Next, a clean 47 m coupon was placed into separate clean 25 mL PTFE wide-mouth bottles (Savillex), and 2% and 14% Fe-added NH4OH were added to the individual wide-mouth bottles. The PTFE wide-mouth bottles containing NH4OH and the membrane coupons were capped and rotated for 16 hours. After 16 hours, the wide-mouth bottles were opened and the membrane coupons were removed. The metal concentration of the membrane-treated NH4OH was determined using inductively coupled plasma mass spectrometry (ICP-MS). The results show that Fe decreased by approximately 94% in 2% NH4OH and by approximately 88% in 14% NH4OH after membrane treatment. The decrease in Fe in the membrane-treated samples confirms the ability of the UPE membrane, with (1,5,7-triazabicyclo[4,4,0]dec-5-ene) incorporated into the surface coating, to remove Fe from 2 and 14% NH4OH when in contact with the solution.

[0082] Example 6 - Measurement of Metal Species Reduction in 25% Hydroxylamine by a Porous Polymeric Resin Containing a Bispicolylamine Ligand Using a Static Immersion Experiment The following examples demonstrate a method used to measure the ability of a porous polymer resin containing bispicolylamine to reduce the metal concentration in 25% hydroxylamine under static immersion conditions. The results demonstrate that the resin containing bispicolylamine is effective in reducing metal species from the solution after contact with the resin.

[0083] A resin (Puromet MTS 9600, Purolite) having a macroporous polystyrene backbone crosslinked with a divinylbenzene polymer to which bispicolylamine is bound was washed using the same method as in Example 1. A 25% hydroxylamine solution containing a given Fe concentration was obtained. Next, 0.2 g of the washed and dried resin was weighed and placed into a clean 25 mL PTFE wide-mouth bottle (Savillex). Next, 20 mL of the 25% hydroxylamine solution was added to the PTFE wide-mouth bottle containing the washed resin. The bottle was capped and rotated for 16 hours. After 16 hours, the resin was allowed to settle and the liquid was decanted into vials for analysis. The metal concentration of each liquid sample was measured by ICP-MS. To ensure reproducibility, the entire experiment was performed in duplicate. This experiment demonstrated that a resin having a macroporous polystyrene backbone crosslinked with a divinylbenzene polymer to which bispicolylamine is bound was able to reduce specific metal species from 25% hydroxylamine by the resin to which bispicolylamine is bound (from Hydroxyl amine from 25% Hydroxyl amine). In this case, Fe was reduced by approximately 77% and Na and Mg were reduced by more than 50%.

[0084] Example 7 - Preparation of the Proposed Ligand (III) Di-tert-butyl dicarbonate is added dropwise to a solution of 2-chloroimidazolidine and triethylamine in dichloromethane (240 mL). The reaction mixture is stirred overnight at room temperature. Water is added and the phases are separated. The organic layer is washed with water and saturated aqueous NaCl solution and then dried over Na2SO4 and evaporated to isolate tert-butyl pyrrolidine-1,3-carboxylate. The isolated product can then be reacted with 4-ethenylbenzenemethanamine in tetrahydrofuran to obtain compound B, which upon acid hydrolysis gives the desired ligand compound (III). TIFF2025090603000016.tif77170Di-tert-butyl dicarbonate Acid hydrolysis

[0085] Aspect In a first aspect, the present disclosure provides a polymer to which a ligand is attached, the ligand comprising at least one moiety represented by the structure: (wherein Q is selected from -CH2-, -N(R)- or CH(N)- and R is a C1-C TIFF2025090603000017.tif42170hydrocarbyl group). 20 A membrane comprising the polymer is provided.

[0086] In a second aspect, the present disclosure provides the membrane of the first aspect, wherein the moiety is a guanidine moiety.

[0087] In a third aspect, the present disclosure provides the membrane of the first aspect, wherein the moiety is an amidine moiety.

[0088] In a fourth aspect, the present disclosure provides the membrane of the first aspect, wherein the moiety has the structure: TIFF2025090603000018.tif37170

[0089] In a fifth aspect, the present disclosure provides a ligand having the structure: ​Provide a film of the first or second aspect, which contains a guanidine moiety bonded via a benzyl group having TIFF2025090603000019.tif92170 (wherein each R is independently selected from hydrogen, C1-C4 alkyl, cyclohexyl and phenyl).

[0090] In the sixth aspect, the present disclosure provides a film of the first aspect, wherein the ligand is a compound having the structure: TIFF2025090603000020.tif89170

[0091] In the seventh aspect, the present disclosure provides a film of the first or second aspect, wherein the ligand is a compound having the structure: TIFF2025090603000021.tif59170

[0092] In the eighth aspect, the present disclosure provides a film of the first or third aspect, wherein the ligand is an amidine moiety having the structure: TIFF2025090603000022.tif43170

[0093] In the ninth aspect, the present disclosure provides a film of the first aspect, wherein the ligand is selected from compounds having the structure: TIFF2025090603000023.tif192170TIFF2025090603000024.tif95170

[0094] In the eleventh aspect, the present disclosure provides a film of the first aspect, wherein the ligand has the structure: TIFF2025090603000025.tif161170 and is selected therefrom

[0095] In the twelfth aspect, the present disclosure provides a film of the first aspect, wherein the ligand has the structure: TIFF2025090603000026.tif72170 and contains the same

[0096] In the thirteenth aspect, the present disclosure provides a film of the first aspect, wherein the ligand is selected from polyguanidines.

[0097] In a 14th aspect, the present disclosure provides a membrane of the 1st aspect, wherein the membrane comprises a porous polymeric filter membrane comprising a polymeric material selected from polyamide, polyimide, polysulfone, polyethersulfone, polyolefin, halogenated polymer, or combinations thereof.

[0098] In a 15th aspect, the present disclosure provides a membrane of the 14th aspect, wherein the polymeric material is selected from ultra-high molecular weight polyethylene and poly(tetrafluoroethylene).

[0099] In a 16th aspect, the present disclosure provides a membrane of the 1st aspect, wherein the filter can reduce the amount of Fe in the aqueous amine by at least 50%.

[0100] In a 17th aspect, the present disclosure provides a membrane of the 1st aspect, wherein the filter can reduce the amount of Fe in the amine by at least 90%.

[0101] In an 18th aspect, the present disclosure provides a membrane of the 1st aspect, wherein the filter can reduce the amount of a metal selected from Na, K, Mg, Mn, Cr, Al, Ni, Zn, Ba, and Pb present in the aqueous amine by at least 50%.

[0102] In a 19th aspect, the present disclosure provides a method for removing impurities from a liquid, the method comprising contacting the liquid, which comprises at least one amine, with a membrane of any one of the 1st to 18th aspects.

[0103] In a 20th aspect, the present disclosure provides a filter comprising a filter membrane of any one of the 1st to 18th aspects.

[0104] In a 21st aspect, the present disclosure provides a liquid composition comprising at least one amine and having less than about 1 ppb of iron.

[0105] In a 22nd aspect, the present disclosure provides a liquid composition of the 21st aspect, comprising hydroxylamine having less than 1 ppb of iron.

[0106] In a 23rd aspect, the present disclosure provides a liquid composition of the 22nd aspect, having less than 0.5 ppb of iron.

[0107] Although several exemplary embodiments of the present disclosure have been described as above, those skilled in the art will readily understand that still other embodiments can be made and used within the scope of the appended claims. Many advantages of the present disclosure covered by this document are described in the foregoing description. However, it will be understood that the present disclosure is merely illustrative in many respects. The scope of the present disclosure is, of course, defined by the language in which the appended claims are expressed.

Claims

1. A porous polymer membrane having attached thereto a ligand comprising a moiety selected from (i) a cyclic guanidine moiety and (ii) a cyclic amidine moiety.

2. The porous polymeric membrane of claim 1 , wherein the moiety is a cyclic guanidine moiety.

3. The porous polymeric membrane of claim 1 , wherein the moiety is a cyclic amidine moiety.

4. The ligand has the structure:

2. The porous polymer membrane of claim 1, wherein the compound has the formula:

5. The ligand has the structure:

2. The porous polymer membrane of claim 1, wherein the compound is selected from the group consisting of:

6. The ligand has the structure:

2. The porous polymer membrane of claim 1, wherein the compound is selected from the group consisting of:

7. 10. The porous polymeric membrane of claim 1, comprising a polymeric material selected from polyamides, polyimides, polysulfones, polyethersulfones, polyolefins, halogenated polymers, or combinations thereof.

8. 10. The porous polymeric membrane of claim 1, wherein the polymeric material is selected from ultra-high molecular weight polyethylene and poly(tetrafluoroethylene).

9. 10. The porous polymeric membrane of claim 1, wherein the filter is capable of reducing the amount of Fe in an aqueous amine by at least 50%.

10. 10. The porous polymer membrane of claim 1, wherein the filter is capable of reducing the amount of Fe in the amine by at least 90%.

11. 10. The porous polymeric membrane of claim 1, wherein the filter is capable of reducing the amount of metals selected from Na, K, Mg, Mn, Cr, Al, Ni, Zn, Ba, and Pb present in the aqueous amine by at least 50%.

12. 13. A method for removing impurities from a liquid, the liquid comprising at least one amine, the method comprising contacting the liquid with the porous polymeric membrane of claim 1.

13. A filter comprising the porous polymeric membrane of claim 1.

14. 10. The porous polymer membrane of claim 1, wherein the ligand is attached to the porous polymer membrane via a benzyl group.

15. 10. The porous polymer membrane of claim 1, wherein the ligand is attached to the porous polymer membrane by (i) via a crosslinked coating, or (ii) by being grafted from the porous polymer membrane.

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