KR102291196B1 - A depth filter for filtering CMP slurry and manufacturing method thereof - Google Patents

Abstract

The filter for CMP slurry filtration according to the present invention coats a hydrophilic polymer on the surface of a nonwoven fabric layer forming the filter, so that particles and gels such as CMP (chemical mechanical planarization) slurry, MLCC (multilayer ceramic capacitor) slurry and photoresist chemicals are coated. It is possible to maximize the filtration effect of the slurry by increasing the affinity with the slurry and composition contained therein, and by lowering the differential pressure applied to the filter.

Description

A depth filter for filtering CMP slurry and manufacturing method thereof

The present invention relates to a filter for slurry filtration in a CMP process and a method for manufacturing the same, and more particularly, to a CMP (chemical mechanical planarization) slurry, MLCC (multilayer ceramic capacitor) by coating a hydrophilic polymer on the surface of a nonwoven fabric layer forming the filter. A depth filter for filtering slurries and compositions containing particles and gels such as slurries and photoresist chemicals.

The wafer polishing technique using a chemical mechanical planarization (CMP) slurry has advantages such as high polishing efficiency and ease of operation compared to the conventional etching method, and is replacing the conventional etching process.

However, the wafer polishing technique using the CMP slurry has a problem in that scratches are generated by large particles in the slurry during polishing. In order to solve this problem, a filter for filtering the CMP slurry is used when preparing the slurry.

In general, the specifications of commercial CMP slurries are governed by solids concentration, pH, specific gravity, average particle size and normal (bulk) particle size distribution, but particles of sizes (>1 μm in diameter) outside the specified size distribution are found. These particles may be agglomerates, aggregates or gels and may be formed by agglomeration, settling, system malfunction or pH changes or local drying of the slurry. These particles can cause micro-scratch and, together with the gel, cause several defects in the planarized wafer surface during the CMP process. Slurry filtration to remove these relatively large particles has proven beneficial in reducing wafer defects and increasing yield in CMP processes.

Filtration, on the other hand, is a type of separation technology that separates fluid and impurity particles by passing impurity particles (contaminants) contained in a fluid (liquid or gas) through a material having pores, such as a mesh or sponge. In the early days, it was manufactured with natural materials such as paper, so it was difficult to remove contaminant particles smaller than 10㎛ due to the lack of various filter materials. ) has been developed to make it possible to separate particles of 0.1 mm or less, and the phenomenon overlaps with the ultrafiltration area at present.

The importance of filtration processes for current or next-generation CMP slurries continues to expand, with the demand for significantly smaller average particle sizes, lower weight ratios of solids, and complex abrasive and chemical compositions. New slurry filtration technology must meet stricter standards for reliable removal of large particles from particles with a diameter of 100 nm or less, constant flow and pressure drop characteristics, extended lifetime, and minimal impact on average working particles and particle distribution. .

Currently, various filter cartridge structures are used to purify fluids, and these cartridge structures are designed to remove microbes as well as solid and colloidal particles. Cartridge types used for filtration of gases and liquids are largely divided into depth filtration filters and pleated surface filtration filters. The depth filtration filter is mainly used to remove contaminants and particles. It is common to use

The main advantages of depth filtration filters are particle holding capacity, high flow rate, low pressure drop and retention. This filter design allows contaminants and particles to be trapped in stages within the depth of the filter due to the multilayer structure of different media types. Placing the densest media in the core adjacent to the liquid outlet and large pore size filtration media in the outer diameter layer adjacent to the liquid inlet ensures efficient particle removal and maximum delay in differential pressure rise due to clogging.

When the contaminant particles contained in the fluid are collected in the filter media by the effects described above, the particles do not stay there, but are again enveloped in the fluid and escape through the filter media. There are several reasons why the particles once captured are again swept away by the fluid and escape with the fluid. If the flow rate of the fluid increases and the flow rate increases, the particles can be swept away by the fluid again. As the pressure increases, the channeling phenomenon occurs in which the pores in a specific area are widened, and particles can escape to this side, and may also come out by the pulsation of the pump.

A well-made filter should have many pores that can trap particles without passing through particles larger than the pore size of the filter media. In order not to pass even a single large particle, the pore size of the filter does not increase even when the pressure is increased, and the filter media has a sufficient thickness so that most of the contaminants can be collected in a layer within 20% of the surface.

In general, a depth filtration filter having a relatively deep filtration layer of several centimeters may be unintentionally compressively deformed under the pressure of a fluid flowing into the filter. The compressibility of the filter layer varies depending on the filter type, the removal capacity of the filter and the thickness of the depth filtration filter. For example, a filter with a thick layer can be compressed more than a filter with a thinner layer. Compression of the filter layer reduces the pore volume and increases the likelihood of clogging. This creates an undesirable dense structure within the filter and causes the differential pressure to rise to maintain the fluid supply rate. This increased differential pressure condition increases the probability of undesirable fluid channeling inside the filter. Such channeling is undesirable because the channeled fluid bypasses the filter bed and thus large particles are not removed from the fluid.

Widely used as a material for such a CMP slurry filter is a fibrous nonwoven fabric manufactured by melt-blown polyolefin resin, especially polypropylene resin, which has the advantage of being able to produce various grades of filter media with various fiber diameters. It is also economical in terms of manufacturing cost. The actual CMP slurry filter uses a depth filtration filter manufactured by laminating various grades of polypropylene-based non-woven media with a thickness of several tens to a maximum of several hundred layers.

In order to develop a filter with micropores used for CMP slurry filters, a calendaring process that compresses the existing non-woven media with heat and pressure is generally used. This can cause an increase in the differential pressure of the filter. This leads to a decrease in porosity as the interconnectivity of pores is rapidly reduced through calendaring, which significantly reduces the flow rate of the slurry passing through the filter and raises the differential pressure, thereby increasing the overall cost of the filtration process.

In addition, as a factor for increasing the resistance of fluid permeation, most fibers constituting the CMP slurry filter are made of a hydrophobic polymer such as polyolefin to secure mechanical properties. In general, the liquid permeation pressure refers to the pressure at which water passes through the dry filter media. The initial differential pressure applied to the fluid gradually decreases as it comes into contact with the surface of the filter and the fluid, and after a certain period of time, it maintains a constant pressure in a steady state. .

However, when the hydrophobicity of the filter medium is high, resistance is taken until the fluid wets the surface of the filter medium when the actual fluid is passed through the filter, which causes the initial differential pressure increase that normally occurs. Due to the low wettability, the effect of improving the differential pressure of the filter is greatly reduced.

Republic of Korea Patent Publication No. 10-2013-0075516 (July 05, 2013)

The present invention has been devised to solve the above problems, and in detail, by coating a hydrophilic polymer on the surface of a nonwoven fabric layer forming a filter, CMP (chemical mechanical planarization) slurry, MLCC (multilayer ceramic capacitor) slurry and photoresist An object of the present invention is to provide a filter for CMP slurry filtration that can maximize the filtration effect of the slurry by increasing the affinity with the slurry and composition containing particles and gels such as chemical substances and reducing the differential pressure applied to the filter, and a method for manufacturing the same do it with

The present invention relates to a filter for CMP slurry filtration and a method for manufacturing the same.

In one aspect of the present invention, a single layer or a nonwoven fabric layer in which two or more filter media layers are laminated is formed on the fiber surface constituting the nonwoven fabric layer,

Any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol and triethylene glycol divinyl ether, hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene Oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose. It relates to a filter for CMP slurry filtration, characterized in that the coating solution containing any one or a plurality of hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose is coated.

In the present invention, the coating solution is N,N'-dimethylacetamide (N,N-dimethylacetamide, DMAc), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N -Dimethylformamide (N,Ndimethylformamide, DMF), Methanol, Ethanol, Propanol, N-butanol, Isopropyl alcohol, Decalin , acetic acid (acetic acid) and glycerol (Glycerol) any one or a plurality of organic solvents 50 to 70% by weight and 30 to 50% by weight of water is characterized in that a mixed solution is used as a solvent.

In addition, the coating solution is characterized in that it contains 15 to 50 parts by weight of a surfactant based on 100 parts by weight of the hydrophilic polymer.

In addition, the coating solution is characterized in that it further comprises a saturated aliphatic hydrocarbon containing any one or a plurality of functional groups selected from the group consisting of an ether group, a hydroxyl group and an amino group.

In the present invention, the fiber constituting the nonwoven layer is any one selected from polyolefin, polyamide, polyacrylic, polyacetal, cellulose ether, cellulose ester, polyalkylene sulfide, polyarylene oxide, polysulfone, and modified polysulfone polymer. or a plurality of components, and the fineness of the fibers constituting the nonwoven layer is 0.01 to 50 μm.

More specifically, the filter may include a support layer made of a non-woven fabric; and a surface layer formed on both sides of the support layer, wherein the fineness of the fibers constituting the support layer is 0.01 to 10 μm, the fineness of the fibers constituting the surface layer is 1 to 20 μm, and the nonwoven layer has a basis weight of 10 to 1,000 g It is characterized as /m2.

In the present invention, the nonwoven fabric layer is characterized in that it is manufactured by any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning.

Another aspect of the present invention is

a) spinning comprising any one or a plurality of components selected from polyolefins, polyamides, polyacrylics, polyacetals, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones and modified polysulfone polymers Forming a nonwoven layer by applying any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning to liquid or fiber;

b) coating any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol, and triethylene glycol divinyl ether on the surface of the nonwoven fabric layer;

c) Hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, and cellulose in the nonwoven fabric layer of step b). coating any one or a plurality of coating solutions selected from carboxymethyl cellulose and hydroxyethyl cellulose; and

d) after washing the nonwoven fabric layer in step c) with water, drying with hot air;

It relates to a filter manufacturing method for CMP slurry filtration, comprising a.

The filter for CMP slurry filtration according to the present invention coats a hydrophilic polymer on the surface of a nonwoven fabric layer forming the filter, so that particles and gels such as CMP (chemical mechanical planarization) slurry, MLCC (multilayer ceramic capacitor) slurry and photoresist chemicals are coated. It is possible to maximize the filtration effect of the slurry by increasing the affinity with the slurry and composition contained therein, and by lowering the differential pressure applied to the filter.

1 is a view showing the water contact angle of the filter prepared in Example 1, the left is a general polypropylene filter of Comparative Example, the right is the filter of Example 1.
FIG. 2 shows the water pressure differential over time of the filter prepared in Example 2, wherein blue is a comparative example of a general polypropylene filter, and red is a filter of Example 1. FIG.
3 is a view showing the flow rate according to the differential pressure of the filter manufactured in Example 2, in which red is a general polypropylene filter of a comparative example, and blue is a filter of Example 1.

Hereinafter, a filter for CMP slurry filtration and a manufacturing method thereof according to the present invention will be described in more detail with reference to Examples and Comparative Examples. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art.

Therefore, the present invention is not limited to the embodiments presented below and may be embodied in other forms, and the embodiments presented below are merely described to clarify the spirit of the present invention, and the present invention is not limited thereto.

At this time, unless there are other definitions in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which this invention belongs, and in the following description, the subject matter of the present invention may be unnecessarily obscured. Descriptions of possible known functions and configurations will be omitted.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

As used herein, the term 'nonwoven fabric' refers to a web including a plurality of randomly distributed fibers. The fibers may generally be bonded to each other or unbonded. The fibers may be staple fibers or continuous fibers. A fiber may include multiple materials as a single material, or as a combination of different fibers, or as a combination of similar fibers each composed of different materials.

For purposes of illustration, the filter media of the present invention are described in connection with use as a filter element in a conventional cartridge filter assembly capable of being combined in fluid communication with a chemical-mechanical polishing (CMP) slurry. Assemblies of this type and their construction are described in commonly assigned US Pat. Nos. 5,154,827, and elsewhere in US Pat. 4,104,170; 4,663,041; 5,154,827; and 5,543,047. However, it will be understood that aspects of the present invention may find utility in other filter assemblies, such as capsules with integral media, housings, fittings, and the like. Therefore, their use in such other applications is expressly considered to be within the scope of the present invention.

The filter for CMP slurry filtration according to the present invention consists of a single layer or a non-woven fabric layer in which two or more media layers are laminated, and on the fiber surface constituting the non-woven fabric layer, polyethylene glycol diolate, nonylphenoxypoly (ethyleneoxy) ethanol and tri Any one or a plurality of surfactants selected from ethylene glycol divinyl ether, hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose . It is characterized in that the coating solution containing any one or a plurality of hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose is coated.

In the present invention, the nonwoven layer is a web composed of a single layer or a multilayer, and the fibers forming the nonwoven layer may be made of a known polymer. At this time, the known polymer is not particularly limited as long as it is a polymer used in the manufacture of general fibers, for example, polyolefin, polyamide, polyacrylic, polyacetal, cellulose ether, cellulose ester, polyalkylene sulfide, polyarylene oxide, polysulfones and modified polysulfone polymers; and the like.

It may also be advantageous to add plasticizers known in the art to the various polymers described above to reduce the Tg of the fibrous polymer when the web is manufactured. A suitable plasticizer will depend on the polymer and the specific end use to which the fiber will be employed in spinning the fiber, and the amount added may also be freely added within a range that does not impair the purpose of the present invention.

As an example of such a plasticizer, a nylon polymer can be plasticized with water or even residual solvent remaining from the electrospinning or electroblowing process. Other plasticizers known in the art that may be useful in lowering the polymer Tg include aliphatic glycols, aromatic sulfanimides, dibutyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dioctyl phthalate, diisodecyl phthalate, diunde selected from the group consisting of syl phthalate, didodecanyl phthalate, and diphenyl phthalate.

In addition, the nonwoven fabric layer may be formed by mixing fibers spun with a fluorine-based compound as needed. The fluorine-based compound can secure the filtration efficiency/flow rate at a desired level without changing the physical properties of the filter medium even if the CMP slurry is a solution of a strong acid/strong base or a solution with a high temperature, and has the advantage of being able to have a long use cycle

As the fluorine-based compound, for example, polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, tetrafluoroethylene-hexafluoropropylene copolymer (FEP) system, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE) system, tetrafluoroethylene-ethylene copolymer (ETFE) system, polychlorotrifluoroethylene (PCTFE) system, chloro It may be any one or a plurality selected from the group consisting of trifluoroethylene-ethylene copolymer (ECTFE)-based and polyvinylidene fluoride (PVDF)-based. More preferably, it may be polyvinylidene fluoride (PVDF) in terms of low manufacturing cost, easy mass production of fibers, and excellent mechanical strength and chemical resistance.

When the fiber (A) made of a general polymer compound and the fiber (B) made of a fluorine-based compound are mixed in the nonwoven layer, A: B is mixed in a ratio of 5 to 8: 2 to 5 by weight in consideration of mechanical and chemical properties It is preferable to do If it is out of the above range, the durability of the filter may be greatly reduced, or it may be difficult to control the hydrophobicity of the filter, so that the filtration ability of the slurry may be greatly reduced.

In the present invention, the non-woven fabric layer is not limited to a manufacturing method. An example of the method for manufacturing the nonwoven layer may be any one or a plurality selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning, preferably melt blown or electrospinning. This is preferable because it can form a large number of nano-sized micropores in the nonwoven fabric layer.

In the present invention, the non-woven fabric layer can freely adjust the fineness, basis weight, thickness, etc. according to the size of the particles contained in the CMP slurry to be filtered. It is preferable that it is 1,000 g/m2.

In particular, when the nonwoven fabric layer according to the present invention is formed by forming a layer of two or more filter media rather than a single layer, it is preferable to adjust the fineness, thickness, basis weight, etc. of the fibers for each layer. For example, if the fineness of the fibers is reduced for each layer, the differential pressure increases while the tortuosity of the slurry increases, but high porosity is expressed, thereby greatly increasing the particle removal rate and the use cycle. In addition, when the basis weight of the nonwoven fabric layer is reduced for each layer, the differential pressure is reduced and the filtration efficiency can be increased.

In more detail, the filter may include a support layer made of a nonwoven fabric; and a surface layer formed on both sides of the support layer, wherein the fibers constituting the support layer have a fineness of 0.01 to 10 μm, a basis weight of 20 to 30 g/m 2 , and a fineness of the fibers constituting the surface layer is 1 to 20 μm , It is preferable to adjust the basis weight to 100 to 500 g / m 2 .

The support layer is for filtering particles of relatively fine size, and when the fineness or basis weight of the nonwoven fabric constituting the support layer is less than the above range, mechanical properties of the filter may decrease and rupture due to differential pressure may occur, exceeding the above range When the filter is manufactured, processability is deteriorated, and the thickness of the nonwoven fabric layer having relatively fine pores is excessively thick, so that the degree of particle load increases and clogging may occur.

In addition, the surface layer is for primary filtering of particles of relatively large size, and when the fineness or basis weight of the nonwoven fabric constituting the surface layer is less than the above range, not only large particles but also small particles are collected in the surface layer, causing clogging of the filter This may be severe, and if the above range is exceeded, the number of particles passing through the surface layer may increase excessively, and clogging of the support layer may occur.

The nonwoven layer may have an average pore size of 1 to 10 μm. In the above range, smooth primary filtration of silica-based or ceria-based (cerium oxide) slurry having an average particle diameter of 0.03 to 0.2 μm and a solid content of 0.5 to 5% by weight is possible, and improved flow rate It can be supplied in layers. If the average pores are less than 1 μm, the particles collected inside the filter increase and the filter may be initially clogged. If the average pores exceed 10 μm, the filtration efficiency may be significantly reduced.

In the present invention, the coating solution is for imparting hydrophilicity to the nonwoven fabric layer, and the hydrophilic component is coated on the surface of the fibers forming the nonwoven fabric by the coating solution, so that the differential pressure can be significantly reduced as the contact angle with the slurry increases.

In the present invention, the coating solution may be composed of a polymer having a hydrophilic group and a solvent. However, before treating the coating solution, it is preferable to first apply and coat a surfactant capable of enhancing the adhesive properties of the polymer.

In the present invention, the surfactant is capable of increasing the surface energy of the nonwoven layer to about 48 dynes/cm. As the surfactant, polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol, triethyleneglycol divinyl ether, and combinations thereof are preferably used. Commercially available products of polyethylene glycol diolate include MAPEG D0400 manufactured by PPG Industries, Inc. of Gurney, Illinois, USA. Triethylene glycol divinyl ether includes Rapidcure DVE-3 from ISP Technologies Inc., Wayne, New Jersey, USA, and nonylphenoxypoly(ethyleneoxy)ethanol is from Rhone-Poulenc Surfactants and Specialties, Inc., Cranberry, New Jersey, USA. Igepal CO 660 and the like are commercially available.

In addition, the surfactant may further include an amphoteric surfactant in addition to the above components. The amphoteric surfactant has the effect of further increasing the adhesion performance of the hydrophilic polymer. Examples of the amphoteric surfactant include a carboxylic acid type having a hydrophilic anionic loudspeaker, an amine halide, an alkylpyridinium salt, a sulfonic acid type. , sulfuric acid ester type, alkyl amino acid type, phosphoric acid type, phosphoric acid ester type and betaine type, imidazoline type, β-alanine type, amino acid type and the like. Preferably, it may include one or more from the group consisting of alkyl betaine, alkyl amidopropyl betaine, alkyl sulfo betaine, alkyl carboxyl betaine, alkyl imidazoline and alkyl amino fatty acid salts.

In the present invention, the surfactant is preferably included in an amount of 15 to 50 parts by weight based on 100 parts by weight of the hydrophilic polymer, and when used by mixing with a solvent, it is preferably included in an amount of 0.01 to 0.9% by weight based on 100 parts by weight of the composition . When the surfactant is added below the above range, the wettability of the filter is greatly reduced, and when it exceeds the above range, the coating thickness of the coating solution becomes thick and the differential pressure may rapidly increase.

In addition, when the general surfactant and the amphoteric surfactant are added together as the surfactant, the general surfactant and the amphoteric surfactant are each preferably mixed in an amount of 5 to 7: 3 to 5 parts by weight.

In the present invention, the hydrophilic polymer is to increase the wettability of the filter to reduce the differential pressure and to increase the filtration characteristics, and is coated on the surface of the filter to impart hydrophilicity to the filter.

As the hydrophilic polymer, for example, hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose. It may be any one or a plurality selected from carboxymethyl cellulose and hydroxyethyl cellulose, and their commercial names include ZELCON 5126 (product of EIDu Pont de Nemours, USA) and MILEASE T (product of Imperial Chemical Industries, UK). , JEFFAMINE (Huntsman) can also fall into this category.

In the present invention, as the solvent, a conventional solvent capable of dissolving the hydrophilic polymer may be used, preferably N,N'-dimethylacetamide (DMAc), N-methylpyrrolidone (Nmethyl pyrrolidone, NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (N,Ndimethylformamide, DMF), methanol, ethanol, propanol, N-butanol (n-butanol), isopropyl alcohol, decalin, any one or a plurality of organic solvents selected from acetic acid and glycerol 50 to 70% by weight and water 30 to It is preferable to use a mixture of 50% by weight because it can increase the dispersibility of the hydrophilic polymer. In addition, the hydrophilic polymer is preferably added in an amount of 0.1 to 5% by weight based on 100% by weight of the total coating solution. If it is less than the above range, the hydrophilicity of the filter may be significantly reduced, and if it exceeds the above range, it is not easy to reduce the weight of the filter, and the size and porosity of the pores may be reduced, so that the differential pressure may be greatly reduced.

In addition, the coating solution may further include a saturated aliphatic hydrocarbon including any one or a plurality of functional groups selected from the group consisting of an ether group, a hydroxyl group and an amino group.

The saturated aliphatic hydrocarbon is added to compensate for the disadvantages of the hydrophilic polymer. When π electrons are present in the basic skeleton of the hydrophilic polymer, these π electrons are attacked by an oxidizing agent and the basic skeleton may be cut. have.

As described above, when the hydrophilic polymer is cross-linked with a saturated aliphatic hydrocarbon group, the cross-linked chain is difficult to be attacked by an oxidizing agent and is stable. However, the ether group, the hydroxyl group and the amino group have a lone pair of electrons but do not have π electrons, so they have a lower nucleophilicity than a high electron density region having π electrons, so that even components such as various oxidizing agents included in the slurry can stably express hydrophilicity.

The saturated aliphatic hydrocarbon is preferably added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the hydrophilic polymer. If the amount is less than the above range, the weather resistance of the coating solution may be greatly reduced, and if it is added in excess of 10 parts by weight, the thickness of the coating layer may be thickened, and the size and porosity of the pores may decrease.

In addition, the coating solution further comprises one or more metal complexes selected from the group consisting of silver, copper, zinc, cadmium, mercury, antimony, gold, aluminum, platinum, palladium, and mixtures thereof in order to further increase adhesion to the fibers, It may further include at least one positively charged compound selected from the group consisting of aluminum sulfate, sodium aluminate, aluminum chloride, aluminum nitrate and aluminum hydroxide, aluminum isopropoxide, aluminum ethoxide and aluminum-t-butoxide. These compounds may be included in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the hydrophilic polymer, but the present invention is not limited thereto.

In addition, a mixture of a silicon compound and titanium dioxide may be further added to the coating solution to maintain hydrophilicity even after long-term use.

In general, as a method of making the surface of a polymer material hydrophilic, it is possible to make the entire coating film hydrophilic using a method of applying a surfactant, etc. and a hydrophilic resin, but it is very difficult to maintain the effect of hydrophilization for a long period of time. Therefore, in order to maintain the hydrophilicity for a long time, it is preferable to add a certain amount of an inorganic material capable of controlling the hydrophilicity of the coating material.

The silicon compound preferably includes perhydropolysilazane. The perhydropolysilazane can greatly improve the physical properties of the coating layer because hardening and crosslinking to silicon dioxide occur quickly when only moisture is present in the vicinity, and silicon (Si), nitrogen (N), hydrogen (H) ), and exhibits hydrophilic performance with a contact angle of about 10 degrees.

In addition, the titanium dioxide (TiO ₂ ) exhibits a contact angle of several tens of degrees or more when not exposed to light, but when exposed to light (ultraviolet rays) on its surface, water does not splash on the surface at all and does not form a contact angle, so it is super hydrophilic. Therefore, hydrophilicity can be expressed for a long period of time.

The silicon compound and titanium dioxide are preferably included in an amount of 0.1 to 5 parts by weight, respectively, based on 100 parts by weight of the hydrophilic polymer. When added in less than the above range, the weather resistance of the thin film may be deteriorated, and when added in excess of the above range, the thickness of the thin film may increase and thus the differential pressure may be greatly increased.

The present invention includes a method for manufacturing the filter as described above. At this time, the manufacturing method of the filter,

a) spinning comprising any one or a plurality of components selected from polyolefins, polyamides, polyacrylics, polyacetals, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones and modified polysulfone polymers Forming a nonwoven layer by applying any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning to liquid or fiber;

b) coating any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol, and triethylene glycol divinyl ether on the surface of the nonwoven fabric layer;

c) Hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, and cellulose in the nonwoven fabric layer of step b). coating any one or a plurality of coating solutions selected from carboxymethyl cellulose and hydroxyethyl cellulose; and

d) after washing the nonwoven fabric layer in step c) with water, drying with hot air;

may include.

As described above, step a) is a step of forming a nonwoven fabric layer, which is the main component of the filter, and is a method commonly applied in the art, for example, spunbond, spunlace, melt blown, needle punching, flash spun and A nonwoven fabric layer may be formed by any one or a plurality of manufacturing methods selected from electrospinning. In this case, when the structure of the nonwoven fabric layer is multi-layered, it is preferable to form the web by a method such as electrospinning or melt blown on the surface of the support layer prepared in advance.

Next, any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol and triethylene glycol divinyl ether is coated on the nonwoven fabric layer. In this case, it is preferable to mix the surfactant with one or more solvents like the hydrophilic polymer to be described later. By including the solvent together as described above, sufficient coating may be made possible by pre-wetting the nonwoven fabric layer with the solvent before coating with the hydrophilic polymer.

The solvent is preferably a mixture of water and an organic solvent such as alcohol, similar to the hydrophilic polymer. In addition, the surfactant is preferably included in an amount of 0.5 to 1% by weight, more preferably 0.7 to 0.9% by weight in the solution, so that the thickness of the coating layer can be adjusted so as not to be too thick while ensuring uniform wetting.

Step b) does not limit the coating method. For example, methods such as wiping, immersion, and spraying may be applied, and preferably, the nonwoven fabric layer is immersed in a solution containing the surfactant for a predetermined time. In addition, after applying the surfactant as described above, it is dried for a certain period of time so that the surfactant remains on the surface of the fiber.

After coating the surfactant, hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose. Any one or a plurality of coating solutions selected from carboxymethyl cellulose and hydroxyethyl cellulose may be coated.

The coating solution is obtained by dissolving the hydrophilic polymer in the same solvent as the solvent used in step b), wherein the hydrophilic polymer contains 1 to 5% by weight, more preferably 1.5 to 3% by weight of the total coating solution, uniform wettability It is preferable because it is easy to express and control the thickness of the coating layer.

In addition, the coating solution may further add one or more crosslinking agents to help crosslinking of the hydrophilic polymer. At this time, for example, the crosslinking agent is ethylene glycol diglycidyl ether, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diglycerin triglycidyl diepoxy compounds such as dil ether, tetraglycerin tetraglycidyl ether, and poly(ethylene glycol) diglycidyl ether; dialdehyde compounds such as glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, hexanedial, heptandial, octanedial, nonandial, and decanedial; Silicon such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and tetrapropoxysilane alkoxide compounds; Vinyl chloride, vinylidene chloride, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, methoxyethyl vinyl ether, methyl vinyl compounds such as oxyethoxyethyl vinyl ether and tetrahydrofurfuryl vinyl ether; allyl compounds such as ethylene glycol monoallyl ether, trimethylolpropane allyl ether, diethylene glycol monoallyl ether, pentaerythritol triallyl ether, and glycerin monoallyl ether; and alkene compounds such as ethylene, propylene, and isobutylene, and these are preferably added in an amount of 0.01 to 1% by weight of the total coating solution.

The step c) also does not limit the coating method as in the step b). For example, methods such as wiping, immersion, spraying, etc. may be applied, and preferably, the nonwoven fabric layer is immersed in the coating solution for a certain time, or the coating solution is injected into a cartridge equipped with a filter and passed through it. It is better to apply it in the way it does.

After the coating solution is applied to the nonwoven fabric layer as described above, the nonwoven fabric layer is washed with water to remove the excess coating solution, and then the hydrophilic polymer is sufficiently crosslinked by hot air drying to complete the filter. The hot air drying temperature is not limited, but crosslinking may be completed by proceeding at 50 to 200° C. for 1 to 120 minutes.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following Examples and Comparative Examples are one of several methods that can be derived through the present invention, and the present invention is not limited by the following Examples or Comparative Examples.

The physical properties of the specimens prepared in the following Examples and Comparative Examples were measured as follows.

(contact angle)

It was measured from the sessile drop method using a static contact angle meter (manufactured by Phoenix 300 Co.) with a CCD (Charge Coupled Device) attached. At this time, the contact angle was measured at a temperature of 20 °C and a relative humidity of 65%.

(Water intrusion pressure)

The differential pressure when standard particles (ISO Fine Dust Particle, PTI Inc, USA) were added to ultrapure water and passed through a tube equipped with a specimen at a surface flow rate of 5.3 cm/sec was measured using a manometer.

(Particle permeation rate, flow rate and particle removal rate)

The particle permeability is measured by passing standard particles (ISO Fine Dust Particle, PTI Inc, USA) in ultrapure water through an air filter medium with an effective area of 100 cm2 at a surface flow rate of 5.3 cm/sec. LLC, USA). It shows that the collection efficiency of target particle|grains is so high that a measured value is low.

(differential pressure change with time)

A commercially available CMP slurry filter (grade: 0.2 micron) was used to coat the coating solution described in Example 1, and the change in water flow differential pressure with time was tested.

(durability)

After fixing both sides of the specimens prepared in Examples and Comparative Examples, a constant force (same force, same moving speed) is applied to the center of the specimen and moved in the vertical direction (stroke: 70 mm) to tension the specimen up and down and contracted. After the specimen was repeatedly moved 1,000 times by using one movement in which the specimen was stretched and contracted up and down, the flow rate and the particle removal rate were measured.

(Example 1)

First, hydrophilic polyolefin (Soarnol K3835N) was mixed in a solvent in which isobutanol and water were mixed in a 6:4 weight ratio to a concentration of 0.7 wt%, and a surfactant (Mapeg® D0440) was further added to prepare a coating solution by adding 0.3 wt% .

Next, the coating solution was thinly coated on a microporous polyethylene nonwoven fabric (basis weight 20 g/m 2 ) to a thickness of 25 μm using a Baker Applicator (Yoshimitsu YBA-1). Then, it was put into a press roll so that the solution could penetrate into the pores inside the surface of the coated nonwoven fabric and was compressed. After washing with ultrapure water to remove the residual solvent, it was dried in a hot air oven (50° C.) for 30 minutes. The surface tension of the coated sample was tested and shown in FIG. 1 .

The left side of FIG. 1 shows a typical polypropylene contact angle of 143 degrees as a result of the surface tension of the polypropylene nonwoven fabric (basis weight 20 g/m2) before coating, and the right figure shows the surface tension of the nonwoven fabric manufactured through the coating presented in Example 1. was measured, and it was confirmed that the contact angle of 40 degrees was greatly improved.

(Example 2)

In order to check physical properties such as a change in differential pressure when the coating solution according to the present invention is applied to a cylindrical cartridge filter, the hydrophilic polyolefin was prepared at a concentration of 0.1 wt% and the surfactant was prepared at 0.07 wt% when the coating solution was prepared in Example 1 .

The composition prepared as described above was subjected to a capsule-type slurry filter (Retention rating: 0.1 μm, material: polypropylene, Maximum forward differential pressure: 0.4 MPa (20°C), Maximum reverse differential pressure: 0.2 MPa (20°C), filtration area: 510cm2) was injected using a suction pump, but a composition corresponding to 3.5 volume ratio of the filter volume was injected and the coating solution passed through. Then, using a vacuum pump, the residual composition inside the filter was removed, and ultrapure water was passed through to wash it completely, and it was dried with hot air at 80° C. and dried completely to complete the specimen.

(Example 3)

In Example 2, when the coating solution was prepared, the hydrophilic polyolefin was prepared at a concentration of 0.5% by weight and the surfactant was prepared at 0.35% by weight, which was a capsule-type slurry filter (Retention rating: 0.2㎛, material: polypropylene, Maximum forward differential pressure: 0.27 MPa (20° C.), Maximum reverse differential pressure: 0.27 MPa (20° C.)) was applied to prepare a specimen.

(Example 4)

When preparing the coating solution in Example 3, the hydrophilic polyolefin was prepared at a concentration of 1 wt% and the surfactant was prepared at 0.7 wt%, except that specimens were prepared in the same manner.

(Example 5)

The coating solution prepared in Example 2 was filled by the volume of the filter using a suction pump, and then left still for 3 minutes. And again, the coating solution inside the filter was completely removed using a vacuum pump. Except that, specimens were prepared in the same manner.

(Example 6)

A generally used 0.1 micron (100 nanometer) cylindrical cartridge filter (length: 10 inches, diameter: 68 mm, inner diameter: 30 mm, filtration area: 510 cm2) was used instead of the capsule-type slurry filter used in Example 3 Hydrophilization treatment was performed in the same manner except that

Initial penetration differential pressure
(water intrusion pressure)
(kgf/cm2) flux
(ml/min) Example 2 before processing 0.58 15 after processing 0.03 21 Example 3 before processing 0.3 33 after processing 0.1 14.9 Example 4 before processing 0.26 17 after processing 0.05 16 Example 5 before processing 0.65 5 after processing 0.1 6 Example 6 before processing 0.26 122 after processing 0.03 124

As shown in Table 1, in the specimens prepared in Examples 2 to 6, the initial osmotic pressure measured using pure water was significantly reduced compared to that measured before coating, and it was confirmed that the flow rate was also greatly increased. This seems to be because the wettability of the filter was greatly increased due to the decrease in surface tension due to the hydrophilic coating. In particular, it was confirmed that the filter of Example 2, which was coated by passing a coating solution containing a hydrophilic polyolefin at a concentration of 0.1 wt% and a surfactant at 0.07 wt% through the filter, showed the best initial osmotic pressure difference.

average particle diameter
(μm) number of particles before filtration
(dog) after filtration coating oil no coating number of particles
(dog) Removal rate
(%) number of particles
(dog) Removal rate
(%) One 132,939 14.8 99.98 127.1 99.9 2 81,826 2.4 99.99 3.1 99.99 3 60,595 1.0 99.99 1.7 99.99 5 25,280 0.6 99.99 One 99.99

Table 2 describes the removal efficiency of impurities according to the particle size of the filter prepared in Example 2, and when looking at the particle removal efficiency before and after treatment, the removal rate for fine particles having a small average particle diameter is improved. .

In addition, as shown in FIG. 2, as a result of measuring the change in water flow differential pressure while passing ultrapure water at a constant flow rate of 300 ml/min through the slurry filter of Example 2, the water flow differential pressure of the filter before treatment with the coating solution started at 0.37 bar, and the time On the other hand, the differential pressure of the filter after treatment with the coating solution decreases from 0.16 bar to 0.1 bar, indicating that the differential pressure is greatly reduced by the coating.

Here, looking at the change in differential pressure according to the change in the flow rate of the slurry filter of Example 2 as shown in FIG. 3, it can be seen that the pass flow rate of the uncoated filter (red) and the coated filter (blue) is significantly different even at the same differential pressure. can For example, it can be seen that the pass flow rate of the uncoated filter is 360 ml/min at 0.2 bar, while the pass flow rate of the coated filter is almost 700 ml/min.

(Example 7)

Specimens were prepared in the same manner as in Example 1, except that 5 parts by weight of an aqueous block of isocyanate hydrophilized with saturated aliphatic hydrocarbons (BL5335, Bayer Material Science, Inc.) was further added to 100 parts by weight of the hydrophilic polymer when preparing the tincture composition in Example 1 . The physical properties of the prepared specimens were measured and shown in Table 3 below.

(Example 8)

A specimen was prepared in the same manner as in Example 7, except for adding 1 part by weight of titanium dioxide (average particle diameter of 3 nm) to 100 parts by weight of the hydrophilic polymer when preparing the coating solution composition. The physical properties of the prepared specimens were measured and shown in Table 3 below.

(Example 9)

In Example 7, when the coating solution composition was prepared, titanium dioxide (average particle diameter 3 nm) and perhydropolysilazane (weight average molecular weight 3,000) were added in the same manner as each other, except that 1 part by weight was added based on 100 parts by weight of the hydrophilic polymer. Specimens were prepared. The physical properties of the prepared specimens were measured and shown in Table 3 below.

(Example 10)

A specimen was prepared in the same manner as in Example 9, except that 8 parts by weight of titanium dioxide (average particle diameter of 3 nm) was further added compared to 100 parts by weight of the hydrophilic polymer when preparing the coating solution composition in Example 9. The physical properties of the prepared specimens were measured and shown in Table 3 below.

(Example 11)

Specimens were prepared in the same manner as in Example 7, except that 8 parts by weight of perhydropolysilazane (weight average molecular weight 3,000) was further added relative to 100 parts by weight of the hydrophilic polymer when preparing the coating solution composition in Example 7. The physical properties of the prepared specimens were measured and shown in Table 3 below.

flux
(ℓ/㎡/hr) Hard particle removal rate
(%) Soft particle removal rate
(%) before seal after seal before seal after seal before seal after seal Example 7 385 513 98 17 85 10 Example 8 385 541 99 29 85 9 Example 9 375 382 99 98 90 89 Example 10 324 335 99 98 90 89 Example 11 310 318 99 99 91 90

As shown in Table 3, it can be seen that the filter according to the present invention exhibits long-term hydrophilicity and particle removal efficiency even after stretching. Specifically, it can be seen that in Examples 7 and 8, in which saturated aliphatic hydrocarbons and titanium dioxide were added during the preparation of the coating solution composition, the hard particles and soft particles removal rates were improved. However, after the tensile test, most of the coating layer was destroyed, so the flow rate increased rapidly, and the particle removal rate also decreased.

As in Example 9, when titanium dioxide and perhydropolysilazane are added together to the coating solution composition, a stable flow rate can be secured, and at the same time, the coating layer is not destroyed even after a tensile test, so that the flow rate and particle removal rate are almost maintained. can be checked This seems to be because perhydropolysilazane was quickly crosslinked in the presence of moisture to form a strong coating film. However, in Examples 10 and 11, in which titanium dioxide or perhydropolysilazane was added over an appropriate range, the physical properties of the coating film were maintained, but it was confirmed that the above components were added too much to block pores of the filter and reduce the flow rate rapidly. .

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (10)

Consists of a single layer or a nonwoven fabric layer in which two or more filter media layers are laminated, the nonwoven fabric layer comprising:
A fiber made of any one or a plurality of polymers selected from polyolefin, polyamide, polyacrylic, polyacetal, cellulose ether, cellulose ester, polyalkylene sulfide, polyarylene oxide, polysulfone and modified polysulfone polymer;
Polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, tetrafluoroethylene-hexafluoropropylene copolymer (FEP)-based, tetrafluoroethylene-hexa Fluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer Fibers made of any one or a plurality of fluorine-based compounds selected from (ECTFE)-based and polyvinylidene fluoride (PVDF)-based compounds are each formed by mixing in a weight ratio of 5 to 8: 2 to 5,
On the surface of the fiber constituting the nonwoven layer,
Any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol and triethylene glycol divinyl ether, hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene Oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose. 100 parts by weight of any one or a plurality of hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose
15 to 50 parts by weight of any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly (ethyleneoxy) ethanol and triethylene glycol divinyl ether;
0.1 to 5 parts by weight of perhydropolysilazane and
A filter for CMP slurry filtration, characterized in that it is coated with a coating solution containing 0.1 to 5 parts by weight of titanium dioxide.
The method of claim 1,
The coating solution is N,N'-dimethylacetamide (N,N-dimethylacetamide, DMAc), N-methylpyrrolidone (Nmethyl pyrrolidone, NMP), dimethyl sulfoxide (dimethyl sulfoxide, DMSO), N,N-dimethylform Amide (N,Ndimethylformamide, DMF), Methanol, Ethanol, Propanol, N-butanol, Isopropyl alcohol, Decalin, Acetic A filter for CMP slurry filtration, characterized in that a solution in which 50 to 70% by weight of any one or a plurality of organic solvents selected from acetic acid and glycerol and 30 to 50% by weight of water is mixed as a solvent .
delete The method of claim 1,
The coating solution is a filter for CMP slurry filtration, characterized in that it further comprises a saturated aliphatic hydrocarbon containing any one or a plurality of functional groups selected from the group consisting of an ether group, a hydroxyl group and an amino group.
delete The method of claim 1,
The filter for CMP slurry filtration, characterized in that the fineness of the fibers constituting the nonwoven layer is 0.01 to 50㎛.
7. The method of claim 6,
The filter is
a support layer made of a non-woven fabric; and
It consists of a surface layer formed on both sides of the support layer;
The fineness of the fibers constituting the support layer is 0.01 to 10 μm,
The filter for CMP slurry filtration, characterized in that the fineness of the fibers constituting the surface layer is 1 to 20㎛.
The method of claim 1,
The nonwoven layer is a filter for CMP slurry filtration, characterized in that the basis weight is 10 to 1,000 g / ㎡.
The method of claim 1,
The nonwoven layer is a filter for CMP slurry filtration, characterized in that it is manufactured by any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning.
a) any one or a plurality of components (A) selected from polyolefins, polyamides, polyacrylics, polyacetals, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones and modified polysulfone polymers; A spinning solution or fiber comprising;
Polytetrafluoroethylene (PTFE)-based, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA)-based, tetrafluoroethylene-hexafluoropropylene copolymer (FEP)-based, tetrafluoroethylene-hexa Fluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer A spinning solution or fiber containing any one or a plurality of fluorine-based compounds (B) selected from (ECTFE)-based and polyvinylidene fluoride (PVDF)-based
A nonwoven fabric layer is formed by applying any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning, wherein A and B are 5 to 8: 2 to 5, respectively. mixing in a weight ratio to form a nonwoven fabric layer;
b) coating any one or a plurality of surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol, and triethylene glycol divinyl ether on the surface of the nonwoven fabric layer;
c) Hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, and cellulose in the nonwoven fabric layer of step b). Coating a coating solution in which 0.1 to 5 parts by weight of perhydropolysilazane and 0.1 to 5 parts by weight of titanium dioxide are mixed with 100 parts by weight of any one or a plurality of hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose; and
d) after washing the nonwoven fabric layer in step c) with water, drying with hot air;
Filter manufacturing method for CMP slurry filtration comprising a.

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