KR20210017508A - A depth filter for filtering CMP slurry and manufacturing method thereof - Google Patents

Abstract

According to the present invention, provided is a filter for chemical mechanical planarization (CMP) slurry filtration which coats a hydrophilic polymer on a surface of a non-woven fabric layer forming the filter to improve affinity with CMP slurry, multi-layer ceramic capacitor (MLCC) slurry, slurry containing particles such as photoresist chemicals and gel, and composition, and maximizing a filtration effect of the slurry by lowering differential pressure applied to the filter.

Description

TECHNICAL FIELD A depth filter for filtering CMP slurry and manufacturing method thereof

The present invention relates to a filter for filtration of slurry in a CMP process and a method of manufacturing the same, and more particularly, 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. It relates to a depth filter for filtering slurries and compositions containing particles and gels such as slurries and photoresist chemicals.

Wafer polishing technology using CMP (Chemical Mechanical Planarization) slurries has advantages such as high polishing efficiency and ease of operation compared to conventional etching methods, and thus replaces the conventional etching process.

However, the wafer polishing technology 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 during the slurry production.

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

On the other hand, filtration is a type of separation technology, which is a method of separating fluid from impurity particles by passing impurity particles (pollutants) contained in a fluid (liquid or gas) through a material having pores such as a mesh or sponge. In the early days, it was difficult to remove contaminated particles of less than 10㎛ because the filter material was not diverse as it was made of natural materials such as paper, but now synthetic polymers of petrochemical derivatives are used as filter materials (PP, PES, PVDF, Nylon 66, etc.). ) Has been developed in a variety of ways to allow separation of particles less than 0.1 mm, and the phenomenon of overlapping with the ultrafiltration area is currently occurring.

The importance of the filtration process in current or next-generation CMP slurries continues to expand as demands for remarkably small average particle size, low weight ratio solids, complex abrasives and chemical compositions. The new slurry filtration technology must meet strengthened criteria for reliable removal of large particles from particles with a diameter of 100 nm or less, constant flow rate and pressure drop characteristics, extended life, 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 solid and colloidal particles as well as microorganisms. The cartridge types used for gas and liquid filtration are largely divided into deep filtration filters and pleated surface filtration filters. The depth filtration filters are mainly used to remove pollutants and particles, and are installed at the front of the surface filtration filter as a pretreatment filter. It is usually used.

The biggest advantages of deep filtration filters are particle holding capacity, high flow rate, low pressure drop and retention. This filter design allows contaminants and particles to be trapped stepwise within the depth of the filter due to the multi-layered structure of the various media types. Placing the densest medium in the core adjacent to the liquid outlet and the large pore size filtration medium 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 contaminated particles contained in the fluid are trapped in the filter media by the effects described above, the particles do not stay there, but are again encased in the fluid and passed through the filter media. There are several reasons why the once trapped particles are swept back into 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 back into the fluid.If the filter is used for a long time, the differential pressure is caused by gradual pore closure. When the pressure increases and the differential pressure increases, a channeling phenomenon that widens the pores in a specific area may occur, causing particles to escape to this direction, and may also come out due to the pulsation of the pump.

A well-made filter must have many pores capable of collecting particles without passing through particles larger than the pore size of the filter media. In order to prevent even one large particle from passing through, the pore size of the filter should be designed so that 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 trapped in a layer within 20% of the surface.

In general, a depth filtration filter having a relatively deep filtration layer of several centimeters may unintentionally compressively deform under the pressure of the 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 deep filtration filter. For example, a filter with a thicker layer can be compressed more than a filter with a thinner layer. When the filter layer is compressed, the void volume is reduced and the likelihood of clogging increases. This causes an undesirable dense structure to be formed in the filter and causes the differential pressure to rise to maintain the fluid supply rate. This increased differential pressure condition increases the probability of undesired channeling of fluid inside the filter. Such channeling is not desirable because the channeled fluid passes through the filter layer 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 made of a polyolefin resin, especially a polypropylene resin in a melt blown method. This is not only the advantage of being able to produce various grades of filter media with various fiber diameters. This is because it is economical in terms of manufacturing cost. In fact, the CMP slurry filter uses a deep filtration filter manufactured by laminating polypropylene-based nonwoven fabric media of various grades to a thickness of several tens to several hundred layers.

In order to develop a filter with micropores used for a CMP slurry filter, a calendering process that compresses the existing nonwoven filter material with heat and pressure is generally used.This makes it possible to refine the pores, but it reduces the porosity of the entire filter. It may cause an increase in the differential pressure of the filter. This leads to a decrease in porosity due to the rapid reduction of the interconnectivity of the pores through calendaring, thereby significantly reducing the flow rate of the slurry passing through the filter and increasing the differential pressure, thereby increasing the overall cost of the filtration process.

In addition, as an element that increases the resistance of fluid permeation, most of the fibers constituting the CMP slurry filter are made of a hydrophobic polymer such as polyolefin in order to secure mechanical properties. In general, the liquid permeation pressure refers to the pressure through which water passes through the dry filter medium, and the initial differential pressure applied to the fluid gradually decreases as the surface of the filter and the fluid come into contact, and after a certain period of time, the steady state pressure is maintained. .

However, when the hydrophobicity of the filter medium is high, resistance is required until the fluid wets the surface of the filter medium when the actual fluid is passed through the filter, which causes an increase in the initial differential pressure that normally occurs.This hydrophobic polymer increases the overall hydrophobicity of the filter. 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 was devised to solve the above problems, 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 It is intended to provide a filter for filtration of CMP slurry and a method for manufacturing the same, which 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. To do.

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

One aspect of the present invention is composed of a single layer or a nonwoven fabric layer in which two or more filter material layers are laminated, on the surface of the fibers forming the nonwoven fabric layer,

Any one or more 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 filtering a CMP slurry, characterized in that a coating solution containing 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-methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N -Dimethylformamide (N,Ndimethylformamide, DMF), methanol, ethanol, propanol, N-butanol, isopropyl alcohol, decalin , A solution in which 50 to 70% by weight of any one or more organic solvents selected from acetic acid and glycerol and 30 to 50% by weight of water are mixed 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 contains a saturated aliphatic hydrocarbon containing one or more functional groups selected from the group consisting of an ether group, a hydroxy group and an amino group.

In the present invention, the fiber constituting the nonwoven layer is any one selected from polyolefin, polyamide, polyacryl, polyacetal, cellulose ether, cellulose ester, polyalkylene sulfide, polyarylene oxide, polysulfone, and modified polysulfone polymer. Or it includes a plurality of components, characterized in that the fineness of the fibers forming the non-woven fabric layer is 0.01 to 50㎛.

In more detail, the filter, a support layer made of a non-woven fabric; And a surface layer formed on both sides of the support layer, the fineness of the fibers forming 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 fabric layer has a basis weight of 10 to 1,000 g It is characterized in that /㎡.

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,

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

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

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

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

It relates to a method for producing a filter for filtering CMP slurry, characterized in that it comprises a.

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

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

Hereinafter, a filter for filtering a CMP slurry according to the present invention and a method of manufacturing the same will be described in more detail with reference to Examples and Comparative Examples. Specific examples introduced below are provided as examples in order to sufficiently convey the spirit of the present invention to those skilled in the art.

Accordingly, the present invention is not limited to the specific examples presented below and may be embodied in other forms, and the specific examples presented below are only 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 and scientific terms used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, and unnecessarily obscure the subject matter of the present invention in the following description. Description of possible known functions and configurations will be omitted.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

In the present invention, the term'nonwoven fabric' means a web including a plurality of randomly distributed fibers. The fibers generally may or may not be bonded to each other. The fibers may be staple fibers or continuous fibers. The fibers may comprise 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 illustrative purposes, the filter media of the present invention are described in connection with their use as filter elements in conventional cartridge filter assemblies that may be coupled in fluid communication with chemical-mechanical polishing (CMP) slurries. Such types of assemblies and their construction are described in commonly assigned U.S. Patent Nos. 5,154,827, and other U.S. Patent Nos. 4,056,476; 4,104,170; 4,663,041; 5,154,827; 5,154,827; And 5,543,047. However, it will be appreciated 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, use within such other applications should be regarded as expressly within the scope of the present invention.

The filter for filtering a CMP slurry according to the present invention is made of a single layer or a nonwoven fabric layer in which two or more filter media layers are laminated, and on the fiber surface constituting the nonwoven fabric layer, polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy) ethanol and tri Any one or more 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 a coating solution containing one or more hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose is coated.

In the present invention, the nonwoven fabric layer is a single-layer or multi-layered web, and the fibers forming the non-woven fabric 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 production of general fibers, and for example, polyolefin, polyamide, polyacrylic, polyacetal, cellulose ether, cellulose ester, polyalkylene sulfide, polyarylene oxide, Polysulfone and modified polysulfone polymers, and the like.

In addition, in order to reduce the Tg of the fibrous polymer during manufacture of the web, it may be advantageous to add plasticizers known in the art to the aforementioned various polymers. Suitable plasticizers will depend on the specific end use in which the polymer and the fibers are to be employed upon spinning of the fibers, and the amount of addition may also be freely added within the range not impairing the object of the present invention.

As an example of the plasticizer, the 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 sulfanomides, dibutyl phthalate, dihexyl phthalate, dicyclohexyl phthalate, dioctyl phthalate, diisodecyl phthalate, diounde. Syl phthalate, didodecanyl phthalate and diphenyl phthalate include, but are not limited to.

In addition, the nonwoven fabric layer may be formed by mixing fibers spun with a fluorine-based compound, if necessary. Even if the CMP slurry is a solution of a strong acid/base or a solution with a high temperature, the fluorine-based compound can secure the filtration efficiency/flow rate at a desired level without changing the physical properties of the filter medium, and has the advantage of having 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 Trifluoroethylene-ethylene copolymer (ECTFE) and polyvinylidene fluoride (PVDF) may be any one or more selected from the group consisting of. 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 weight ratio of 5 to 8: 2 to 5 in consideration of mechanical and chemical properties. It is desirable to do. If it is out of the above range, the durability of the filter may be greatly deteriorated, or it is difficult to control the hydrophobicity of the filter, so that the filtering ability of the slurry may be greatly reduced.

In the present invention, the nonwoven fabric layer is not limited to a manufacturing method. Examples of the method of manufacturing the nonwoven fabric layer may be any one or a plurality selected from spunbond, spunlace, melt blown, needle punching, flash spun, and electrospinning, and preferably, melt blown or electrospinning is used. It is preferable because a large number of nano-sized micropores can be formed in the nonwoven fabric layer.

In the present invention, the nonwoven fabric layer can freely adjust fineness, basis weight, and thickness, etc. according to the size of the particles included in the CMP slurry to be filtered. For example, the fineness of the fibers forming the nonwoven fabric layer is 0.01 to 50 μm, and the basis weight is 10 to It is better to be 1,000 g/㎡.

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

In more detail, the filter includes a support layer made of a nonwoven 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 basis weight is 20 to 30 g/m 2, and the fineness of the fibers constituting the surface layer is 1 to 20 μm. , The basis weight is preferably adjusted to 100 to 500g/m2.

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

In addition, the surface layer is for primarily filtering particles of a relatively large size, and when the fineness or basis weight of the nonwoven fabric forming the surface layer is less than the above range, not only particles having large particle diameters but also small particles are trapped in the surface layer, causing clogging symptoms of the filter. This may become severe, and if the above range is exceeded, the number of particles passing through the surface layer may be excessively increased, resulting in clogging of the support layer.

The nonwoven layer may have an average pore size of 1 to 10 μm. In the above range, smooth primary filtration of a 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 Can be supplied in layers. If the average pore size is less than 1 μm, the particles to be collected may increase toward the inside of the filter, resulting in an initial clogging of the filter. If the average pore size exceeds 10 μm, there may be a problem that the filtration efficiency is significantly lowered.

In the present invention, the coating solution is for imparting hydrophilicity to the nonwoven fabric layer, and a hydrophilic component is coated on the surface of the fiber 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 made of a polymer and a solvent having a hydrophilic group. However, before the coating solution is treated, it is preferable to coat by first applying a surfactant that can improve the adhesive properties of the polymer.

In the present invention, the surfactant is capable of increasing the surface energy of the nonwoven fabric layer to about 48 dynes/cm. It is preferable to use polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy)ethanol, triethylene glycol divinyl ether, and combinations thereof as such surfactants. Commercially available products of polyethylene glycol diolate include MAPEG D0400 of PPG Industries, Inc. of Gurney, Illinois, USA. Triethylene glycol divinyl ether is Rapidcure DVE-3 from ISP Technologies Inc. of Wayne, NJ, and nonylphenoxypoly(ethyleneoxy) ethanol is from Rhone-Poulenc Surfactants and Specialties, Inc. of Cranberry, NJ, 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 an effect of further increasing the adhesion performance of the hydrophilic polymer, and examples of such amphoteric surfactants are carboxylic acid type, amine halide, alkylpyridinium salt, sulfonic acid type having a hydrophilic anionic speaker. , 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 salt.

In the present invention, the surfactant preferably contains 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 preferable to contain 0.01 to 0.9% by weight based on 100% by weight of the composition. . When the surfactant is added below the above range, the wettability of the filter is greatly deteriorated, and when the above range is exceeded, the coating thickness of the coating solution becomes thick and the differential pressure may increase rapidly.

In addition, when a general surfactant and an amphoteric surfactant are added together as a surfactant, it is preferable that the general surfactant and the amphoteric surfactant are mixed in the range of 5 to 7: 3 to 5 parts by weight, respectively.

In the present invention, the hydrophilic polymer is intended to increase the wettability of the filter to reduce differential pressure and increase 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 more 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, the solvent may be a conventional solvent capable of dissolving the hydrophilic polymer, preferably N,N'-dimethylacetamide (N,N-dimethylacetamide, DMAc), N-methylpyrrolidone (Nmethyl pyrrolidone, NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), methanol, ethanol, propanol, N-butanol (n-butanol), isopropyl alcohol (Isopropyl alcohol), decalin (Decalin), acetic acid (acetic acid) and glycerol (Glycerol) any one or a plurality of organic solvents selected from 50 to 70% by weight and 30 to 30% by weight of water It is preferable to mix and use 50% by weight because it can increase the dispersibility of the hydrophilic polymer. In addition, the hydrophilic polymer is preferably added in the range of 0.1 to 5% by weight of the total coating solution 100% by weight. If it is less than the above range, the hydrophilicity of the filter may be remarkably deteriorated, 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 decrease, so that the differential pressure may be significantly reduced.

In addition, the coating liquid may further contain a saturated aliphatic hydrocarbon containing any one or a plurality of functional groups selected from the group consisting of an ether group, a hydroxy group, and an amino group.

The saturated aliphatic hydrocarbon is added to compensate for the disadvantages of the hydrophilic polymer, and when π electrons are present in the basic skeleton of the hydrophilic polymer, there may be cases where the basic skeleton is cleaved due to the attack of such π electrons by an oxidizing agent. have.

As described above, when the hydrophilic polymer is crosslinked only with saturated aliphatic hydrocarbon groups, such a crosslinked chain is difficult to attack by an oxidizing agent and is stable. However, the ether group, the hydroxy group, and the amino group have a lone electron pair, but do not have π electrons, and are less nucleophilic than the high electron density site having π electrons, and thus can stably exhibit hydrophilicity even in components such as various oxidizing agents contained in the slurry.

It is preferable to add 1 to 10 parts by weight of the saturated aliphatic hydrocarbon based on 100 parts by weight of the hydrophilic polymer. If it is added less than the above range, the weather resistance of the coating liquid may be greatly deteriorated, and if it is added in excess of 10 parts by weight, the thickness of the coating layer may become thick, and thus the size and porosity of the pores may decrease.

In addition, the coating solution further includes at least one metal complex compound 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 fibers, or It may further include one or more positively charged compounds 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 contain 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 in order to maintain hydrophilicity even for long-term use.

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

As the silicon compound, it is preferred to include perhydropolysilazane. The perhydropolysilazane can be rapidly cured and crosslinked with silicon dioxide when only moisture is present around it, so the physical properties of the coating layer can be greatly improved, and by itself, silicon (Si), nitrogen (N), and hydrogen (H) ), and exhibits a hydrophilic performance of about 10 degrees at a contact angle.

In addition, the titanium dioxide (TiO ₂ ) exhibits a contact angle of tens of degrees or more in a state where it is not exposed to light, but when light (ultraviolet rays) is applied to the surface, water does not splash on the surface and does not form a contact angle, so it is super hydrophilic Therefore, it can exhibit long-term hydrophilicity.

The silicon compound and titanium dioxide are preferably contained in an amount of 0.1 to 5 parts by weight, respectively, based on 100 parts by weight of the hydrophilic polymer. If it is added below the above range, the weather resistance of the thin film may be deteriorated, and if it is added beyond the above range, the thickness of the thin film may increase, thereby greatly increasing the differential pressure.

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

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

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

c) Hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose on the nonwoven fabric layer of the above b) step. Coating any one or a plurality of coating solutions selected from carboxymethylcellulose and hydroxyethylcellulose; And

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

It may include.

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

Next, the nonwoven fabric layer is coated with one or more surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy) ethanol, and triethylene glycol divinyl ether. At this time, it is preferable to mix and use the surfactant in one or more solvents, such as a hydrophilic polymer to be described later. By including a solvent as described above, sufficient coating may be achieved by pre-wetting the nonwoven fabric layer with a solvent before coating with a 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 contained in the range of 0.5 to 1% by weight, more preferably 0.7 to 0.9% by weight in the solution, because it is possible to adjust the thickness of the coating layer so as not to be too thick while ensuring uniform wetting.

The 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 certain period of time. In addition, after applying the surfactant as described above, it is dried for a certain 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, and cellulose. Any one or a plurality of coating solutions selected from carboxymethylcellulose and hydroxyethylcellulose 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, in 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 aid crosslinking of the hydrophilic polymer. At this time, examples of the crosslinking agent include ethylene glycol diglycidyl ether, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, propylene glycol diglycidyl ether, diglycerin triglycidyl ether. Diepoxy compounds such as diether, tetraglycerin tetraglycidyl ether, and poly(ethylene glycol) diglycidyl ether; Dialdehyde compounds such as glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, hexanedial, heptanedial, octanedial, nonandial, and decandial; 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, meth 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; Alkene compounds such as ethylene, propylene, and isobutylene may be mentioned, and these are preferably added in the range 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. can be applied, and preferably, the nonwoven fabric layer is immersed in the coating solution for a certain period of time, or the coating solution is injected into the cartridge in which the filter is installed to pass through. It is good to apply it in a way that says.

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

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 through the following Examples and Comparative Examples were measured as follows.

(Contact angle)

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

(Water intrusion pressure)

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

(Particle transmittance, flow rate and particle removal rate)

Particle transmittance is passed through ultrapure water with standard particles (ISO Fine Dust Particle, PTI Inc, USA) at a cotton flow rate of 5.3 cm/sec through a filter medium for an air filter with an effective area of 100 cm2, and collect the filtrate before filtration and use a particle analyzer (PSS). LLC, USA). The lower the measured value, the higher the collecting efficiency of the target particles.

(Differential pressure change over time)

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

(durability)

After fixing both sides of the specimen prepared through the Examples and Comparative Examples, a certain force (same force, same moving speed) was applied to the center of the specimen to move in the vertical direction (stroke: 70 mm) to pull the specimen up and down and Contracted. After the specimen was stretched and contracted up and down as a single exercise, a total of 1,000 repeated movements were performed, and the flow rate and particle removal rate were measured.

(Example 1)

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

Next, the coating solution was thin-film coated on a microporous polyethylene nonwoven fabric (basis weight 20 g/m 2) with a thickness of 25 μm using a Baker Applicator (Yoshimitsu YBA-1). Then, the coated nonwoven fabric was put into a press roll so that the solution could penetrate into the pores inside the surface and pressed. After washing with ultrapure water to remove 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 the contact angle of 143 degrees, which is a general polypropylene contact angle 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 shown in Example 1. It was confirmed that the contact angle of 40 degrees was significantly improved by measuring.

(Example 2)

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

The composition prepared as described above is used in a capsule type slurry filter (Rentention rating: 0.1㎛, material: polypropylene, maximum forward differential pressure: 0.4 MPa(20℃), maximum reverse differential pressure: 0.2 MPa(20℃), filtration area: 510㎠) A composition corresponding to 3.5 volume ratio was injected and the coating solution was passed. Then, the residual composition inside the filter was removed using a vacuum pump, and it was thoroughly washed by passing ultrapure water, which was dried with hot air at 80°C to complete the specimen.

(Example 3)

When preparing the coating solution in Example 2, a hydrophilic polyolefin was prepared at a concentration of 0.5% by weight and a surfactant was prepared at 0.35% by weight, and this was obtained by using a capsule type slurry filter (Rentention rating: Samples were prepared by applying 0.2㎛, material: polypropylene, maximum forward differential pressure: 0.27 MPa (20°C), maximum reverse differential pressure: 0.27 MPa (20°C)).

(Example 4)

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

(Example 5)

The coating solution prepared in Example 2 was filled as much as the volume of the filter using a suction pump, and then allowed to stand for 3 minutes. And again, the coating solution inside the filter was completely removed using a vacuum pump. Except for the same method, the specimen was prepared.

(Example 6)

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

Initial penetration differential pressure
(water intrusion pressure)
(kgf/㎠) 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 through Examples 2 to 6, it was confirmed that the initial penetration differential pressure measured using pure water decreased significantly compared to that measured before coating, and the flow rate also increased significantly. This seems to be due to a large increase in the wettability of the filter due to the decrease in surface tension due to the hydrophilic coating. In particular, it was confirmed that the filter of Example 2, coated by passing a coating solution containing a hydrophilic polyolefin at a concentration of 0.1% by weight and a surfactant at a concentration of 0.07% by weight, through the filter, exhibits the best initial penetration differential pressure.

Average particle diameter
(㎛) Number of particles before filtration
(dog) After filtration Coating existence 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 shows the removal efficiency of impurities according to the particle size of the filter manufactured in Example 2, and looking at the particle removal efficiency before and after treatment, it is shown that the removal rate for fine particles having a small average particle diameter is improved. .

In addition, as a result of measuring the change in water flow differential pressure while passing 300 ml/min of ultrapure water at a constant flow rate through the slurry filter of Example 2 as shown in FIG. 2, the water flow differential pressure of the filter before treating the coating liquid started at 0.37 bar and the time was increased. It can be seen that the differential pressure decreases significantly due to the coating due to the decrease in aging and dropping to 0.32 bar, while the water flow differential pressure of the filter after treatment with the coating liquid decreased from 0.16 bar to 0.1 bar.

Here, as shown in FIG. 3, when looking at the change in the differential pressure according to the change in the flow rate of the slurry filter of Example 2, it can be seen that the uncoated filter (red) and the coated filter (blue) have a large difference in flow rate through the same differential pressure. I can. For example, at 0.2 bar, the flow rate of the uncoated filter was 360 ml/min, whereas the flow rate of the coated filter was almost 700 ml/min.

(Example 7)

A specimen was prepared in the same manner as in Example 1, except that 5 parts by weight of the hydrophilic block isocyanate aqueous solution (BL5335, Bayer Material Science Co., Ltd.) were added to 100 parts by weight of the hydrophilic polymer when preparing the tinting solution composition with a saturated aliphatic hydrocarbon. . The physical properties of the prepared specimens were measured and described in Table 3 below.

(Example 8)

A specimen was prepared in the same manner as in Example 7, except that 1 part by weight of titanium dioxide (average particle diameter 3 nm) was further added 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 described in Table 3 below.

(Example 9)

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

(Example 11)

A specimen was prepared in the same manner as in Example 7, except that 8 parts by weight of perhydropolysilazane (weight average molecular weight of 3,000) was further added 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 described in Table 3 below.

flux
(ℓ/㎡/hr) Hard particle removal rate
(%) Soft particle removal rate
(%) Before seal After tension Before seal After tension Before seal After tension 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, in Examples 7 and 8 in which saturated aliphatic hydrocarbons and titanium dioxide were added when preparing the coating liquid composition, it can be seen that the removal rate of hard particles and soft particles is improved. However, after performing the tensile test, most of the coating layer was destroyed, so that the flow rate increased rapidly, and the particle removal rate also decreased.

When titanium dioxide and perhydropolysilazane are added to the coating liquid composition together as in Example 9, a stable flow rate can be ensured, and the coating layer is not destroyed even after performing a tensile test, so that the flow rate and particle removal rate are almost maintained. I can confirm. This seems to be due to the fact that perhydropolysilazane was instantly crosslinked in the presence of moisture to form a strong coating. However, in Examples 10 and 11 in which titanium dioxide or perhydropolysilazane was added more than an appropriate range, the physical properties of the coating film were maintained, but too much of the above components were added to block the pores of the filter. .

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains will be able to make various modifications and variations without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (10)

Consisting of a single layer or a nonwoven fabric layer in which two or more filter material layers are laminated, on the fiber surface forming the nonwoven fabric layer,
Any one or more 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. Filter for CMP slurry filtration, characterized in that the coating solution containing one or more hydrophilic polymers selected from carboxymethyl cellulose and hydroxyethyl cellulose is coated.
The method of claim 1,
The coating solution is N,N'-dimethylacetamide (N,N-dimethylacetamide, DMAc), N-methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylform Amide (N,Ndimethylformamide, DMF), methanol, ethanol, propanol, N-butanol, isopropyl alcohol, decalin, acetic CMP slurry filtration filter, characterized in that a solution in which 50 to 70 wt% of an organic solvent selected from acid and glycerol is mixed with 50 to 70 wt% of water and 30 to 50 wt% of water is used as a solvent .
The method of claim 1,
The coating liquid is a filter for filtering a CMP slurry, characterized in that it contains 15 to 50 parts by weight of a surfactant based on 100 parts by weight of the hydrophilic polymer.
The method of claim 1,
The coating solution further comprises a saturated aliphatic hydrocarbon containing one or more functional groups selected from the group consisting of an ether group, a hydroxy group and an amino group.
The method of claim 1,
The fibers constituting the nonwoven fabric layer may be selected from polyolefins, polyamides, polyacrylics, polyacetals, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones, and modified polysulfone polymers. A filter for filtration of CMP slurry comprising a component.
The method of claim 1,
CMP slurry filtration filter, characterized in that the fineness of the fibers forming the non-woven layer is 0.01 to 50㎛.
The method of claim 6,
The filter,
A support layer made of non-woven fabric; And
Consists of; surface layers formed on both sides of the support layer,
The fineness of the fibers forming the support layer is 0.01 to 10 μm,
CMP slurry filtration filter, characterized in that the fineness of the fibers forming the surface layer is 1 to 20㎛.
The method of claim 1,
The filter for filtering a CMP slurry, wherein the nonwoven fabric layer has a basis weight of 10 to 1,000 g/m 2.
The method of claim 1,
The non-woven fabric layer is a filter for CMP slurry filtration, characterized in that produced by any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun and electrospinning.
a) Spinning comprising any one or more components selected from polyolefins, polyamides, polyacrylics, polyacetals, cellulose ethers, cellulose esters, polyalkylene sulfides, polyarylene oxides, polysulfones and modified polysulfone polymers Forming a nonwoven fabric layer by applying any one or a plurality of manufacturing methods selected from spunbond, spunlace, melt blown, needle punching, flash spun, and electrospinning to the liquid or fiber;
b) coating the surface of the nonwoven fabric layer with one or more surfactants selected from polyethylene glycol diolate, nonylphenoxypoly(ethyleneoxy) ethanol, and triethylene glycol divinyl ether;
c) Hydrophilic polyester, alkoxylated polyamine, polyvinyl alcohol, polyacrylamide, polyethylene oxide, polyethyleneimine, polyvinylpyrrolidone, methylcellulose, cellulose on the nonwoven fabric layer of the above b) step. Coating any one or a plurality of coating solutions selected from carboxymethyl cellulose and hydroxyethyl cellulose; And
d) washing the nonwoven fabric layer in step c) with water and drying with hot air;
CMP slurry filtration filter manufacturing method comprising a.

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