KR100801325B1 - Method of preparation chemical filter for air cleaning by reaction injection molding process - Google Patents

Abstract

The present invention relates to a method for manufacturing a chemical adsorption filter for air purification by combining an adsorbent to an organic or inorganic fiber filament, comprising: spinning isocyanate and polyol by reacting injection molding; Applying an adsorbent to the surface of the polyurethane yarn; Chemically bonding an unreacted functional group and an adsorbent on the surface of the yarn; Preparing a filter medium by molding a polyurethane yarn in which the adsorbent is chemically bonded to a surface; And a step of completing the polymerization of the polyurethane spinning yarn chemically bonded to the surface of the adsorbent, wherein the adsorbent is separately used to bond the adsorbent to the organic or inorganic fiber filaments. No chemical coating process is required because the process of coating is not necessary, and the active surface of the adsorbent material caused by the adhesive is not blocked. Provided are methods of making long chemisorption filters.

Injection molding, fiber filament, polyurethane, air purification, chemisorption filter, adhesive

Description

Method of preparation chemical filter for air cleaning by reaction injection molding process

The present invention relates to a method for manufacturing a chemical adsorption filter for air purification by combining an adsorbent to an organic or inorganic fiber filament, comprising: spinning isocyanate and polyol by reacting injection molding; Applying an adsorbent to the surface of the polyurethane yarn; Chemically bonding an unreacted functional group and an adsorbent on the surface of the yarn; Preparing a filter medium by molding a polyurethane yarn in which the adsorbent is chemically bonded to a surface; And a step of completing the polymerization of the polyurethane spinning yarn chemically bonded to the surface of the adsorbent, wherein the adsorbent is separately used to bond the adsorbent to the organic or inorganic fiber filaments. No chemical coating process is required because the process of coating is not necessary, and the active surface of the adsorbent material caused by the adhesive is not blocked. Provided are methods of making long chemisorption filters.

In semiconductor manufacturing plants and precision electronics manufacturing plants, semiconductors and precision electronic components are manufactured in clean rooms. The clean room is isolated from outside air in the HEPA filter or the ULPA filter, thereby creating a dust-free atmosphere. However, intrusion of outside air cannot be completely prevented. In addition, acids, alkalis, and organic substances generated from the clean room constituent members become gaseous or fine particles and diverge in the air, which causes defects. These contaminants are removed by various means. When the concentration is lowered to about ppb or less, the chemisorption filter used in the clean room is usually made of polyurethane, such as activated carbon, ion exchange fiber, or ion exchange resin impregnated with acid or alkali. It is used after adhesion with an adhesive to a skeleton substrate made of polymer such as polyethylene, polypropylene, or the like. Among these filters, acid- and alkali-impregnated chemically impregnated activated carbon contains more neutral salts that precipitate than the amount of the impregnated chemicals, which increases the risk of pressure loss due to contamination and blockage of the filter. There is a high risk of spillage of additives. Therefore, the impregnated activated carbon has a problem in that it is difficult to establish a stable environment of the process due to the tendency of increasing the humidity suppression of the installation. In addition, acid and alkali impregnated activated carbon is prepared by impregnating phosphoric acid, potassium hydroxide, and potassium permanganate. Since the impregnated material has high volatility, secondary contamination may occur due to volatilization, making it difficult to use in chemical manufacturing processes .

In addition, another method of removing toxic gases uses ion exchange fibers, but these fibrous filters have a problem in that the total ion exchange capacity is small. Therefore, there is a need for the production of nonwoven fabrics in which the ion exchange fibers are molded into high density paper. Such an ion exchange nonwoven fabric has a disadvantage in that a sudden increase in pressure results in a sudden pressure loss and a small ion exchange capacity, thus resulting in a short lifetime and limited ion exchange capacity.

In another method, an ion exchange filter having an ion exchange resin attached to a polymer backbone such as polyurethane, polyethylene, or polypropylene is used. In this case, although the differential pressure and ion exchange capacity are secured to some extent, since the ion exchange resin is attached to the polyurethane foam with an adhesive, the adhesive adheres to the surface of the ion exchange resin, resulting in poor ion exchange ability and adhesion due to aging of the adhesive. Part of the ion exchange resin that has been falling occurs, the ion exchange capacity is lowered if the use continues, the ability to remove harmful gases is reduced.

In addition to overcoming the limitations of the conventional method of manufacturing a chemisorption filter, there is a need for a chemisorption filter using a filter material having a low differential pressure, a large ion exchange capacity, and a high gas removal efficiency.

The present invention provides a method of manufacturing a chemical adsorption filter for air purification by bonding an adsorbent to an organic or inorganic fiber filament, comprising: spinning through a reaction injection molding by mixing isocyanate and polyol; Applying an adsorbent to the surface of the polyurethane yarn; Chemically bonding an unreacted functional group and an adsorbent on the surface of the yarn; Preparing a filter medium by molding a polyurethane yarn in which the adsorbent is chemically bonded to a surface; And it provides a method for producing a chemical adsorption filter for air purification comprising the step of completing the polymerization of the polyurethane spinning yarn of the adsorbent chemically bonded to the surface.

Method for producing a chemisorption filter for air purification of the present invention is a reaction injection molding step of mixing isocyanate and polyol for 1 to 10 seconds at 25 ~ 45 ℃, spinning the polyurethane polymer in which the polymerization reaction is initiated through the spinning nozzle; Applying an adsorbent to the surface of the polyurethane yarn; Chemically bonding an unreacted functional group and an adsorbent on the surface of the yarn; Preparing a filter medium by molding a polyurethane yarn in which the adsorbent is chemically bonded to a surface; And completing the polymerization of the polyurethane yarn of the adsorbent chemically bonded to the surface.

Hereinafter, the present invention will be described in detail.

Isocyanates useful in the present invention include aliphatic, aromatic isocyanates or polyisocyanates, or resins having terminal isocyanate groups. The resin is a monomer or polymeric isocyanate. Typical monomer isocyanates include toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,6-hexamethylene diisocyanate (HDI), phenyl isocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone di Isocyanate (IPDI), meta-tetramethylxylene diisocyanate (TMXDI), nonanetriisocyanate (TTI), vinyl isocyanate and the like. The monomer isocyanates are those used more generally, but are not meant to be exclusive. Polymeric polyisocyanates useful in the present invention include isocyanurates, allophanates or biuret compounds, and polyurethane products derived from these monomeric diisocyanates. Addition products of monomeric isocyanates with polyesters containing terminal isocyanate groups and polyether polyols are also useful.

Polyols in the present invention include monomeric compounds or polymer compositions containing two or more hydroxy groups per molecule. The polyols may contain other functional groups such as carboxy, amino, urea, carbamate, amides and epoxy groups. Polyols, blends of polyols, or combinations of polymeric polyols and monomeric diols can be used in solvent-free systems, or as solutions in organic solvents or as dispersions / emulsions in water. Typical examples include polyether polyols, polyester polyols, acrylic polyols, alkyd resins, polyurethane polyols, and the like. Polyether polyols are the reaction products of ethylene or propylene oxide or tetrahydrofuran with diols or polyols. Polyethers derived from natural products such as synthetic epoxy resins and cellulose can also be used in the present invention. Typical polyester polyols are prepared by the reaction of diols, triols or other polyols with di- or polybasic acids. Acrylic polyols are polymerization products of hydroxy containing monomers and esters of acrylic or methacrylic acid, such as hydroxyethyl, hydroxypropyl or hydroxybutyl esters of acrylic or methacrylic acid. These acrylic polymers may also contain other vinyl monomers such as styrene, acrylonitrile vinyl chloride and the like. Polyurethane polyols are also useful in the present invention. These are the reaction products of polyether or polyester polyols with diisocyanates. The polyols are exemplary and are not meant to limit the scope of the present invention.

Each isocyanate and polyol is mixed and adjusted in a range of 0.1: 1 to 10.0: 1 from each of the stored reservoirs, and preferably 0.3: 1 to 1.2: 1 is mixed. 0.01 to 0.3% by weight of the total resin (a combined amount of isocyanate and polyol) is added during the mixing, and generally, the mixture is mixed at 25 to 40 ° C. for 1 to 10 seconds, and then the polyurethane polymer in which the polymerization is initiated is spun through the spinning nozzle. do. The yarn has an average diameter of 0.1 to 2 mm, preferably 0.5 to 1.5 mm. If the average diameter of the spun yarn is less than 0.1 mm, the strength of the appropriate spun yarn required for molding in a later process cannot be obtained. If it exceeds 2 mm, the weight of the chemisorption filter increases and the pressure loss increases.

As the catalyst used in the polymerization reaction, commonly used polyurethane catalysts include tin octoate, triethylamine, triethylenediamine, tetramethylbutanediamine, dibunyl tindilaurate, 1,4-diazocyclooctane, and the like. It is preferable to use but is not limited thereto. The catalyst concentration used is generally a compromise between the pot life of the formulation and the required cure rate.

According to the amount of the adsorbent to the spinning yarn undergoing the polymerization reaction is applied through a conventional air spray or airless spray.

As the adsorbent, various adsorbents produced by conventional techniques, for example, porous ion exchange resin adsorbents, porous organic-inorganic composite adsorbents, impregnated activated carbon, or porous inorganic adsorbents may be used. Such adsorbents are prepared in spherical, granule, or extrudate form, wherein the average particle diameter (d) of the adsorbent is produced in various shapes and sizes within the range of 0.05-2.00 mm.

These adsorbents are used by selecting any one of the adsorbents described above according to the harmful substances to be removed. For example, when the noxious gas is an acid gas such as HF, HCI, SOx, or the like, an alkaline ion exchange resin adsorbent, an organic-inorganic hybrid type adsorbent, an impregnated activated carbon, or a zeolite may be effective. In the case of, it is effective to use an acidic ion exchange resin adsorbent, an organic-inorganic hybrid adhesive, an impregnated activated carbon, or a zeolite. In addition, in the case of volatile organic compounds such as organic amines, organic solvents, ozone (O ₃ ), dioxin, and phthalate plasticizers such as DOP, it is difficult to remove adsorption by acidic-alkaline neutralization, and harmful by capillary phenomenon by micropores. In this case, porous adsorbents having a high specific surface area of 500 m 2 / g or more, such as impregnated activated carbon or zeolite, are used.

The ion exchange resin type adsorbent is a porous adsorbent having a specific surface area of 300 m 2 / g or more and is divided into anionic and cationic exchange resins according to the types of functional groups attached to the resin surface. These ion exchange resin type adsorbents are composed of spheres with an average particle diameter (d) in the range of 0.1 to 1.0 mm, and ion exchange capacity is 1.0 to 4.0 equivalents / kg, adsorbing harmful gases through neutralization reactions with harmful gases. Will be removed.

The organic-inorganic composite adsorbent is a grafting adsorbent having an organic adsorbent component having a functional group on the surface of a porous inorganic carrier having a large surface area. Herein, the inorganic carrier may be a material having a specific surface area of 300 m 2 / g or more, such as silica, alumina, zeolite, or mesoporous material (MCM-41, etc.), and the inorganic carrier may have an average particle size (d). It is prepared to be used in the form of particles or spheres of 0.05 to 0.20 mm. In addition, examples of the organic material for attaching the inorganic carrier include a functional group having an -OH group such as -RSO ₃ H or -RNH ₄ OH, and the organic adsorbent component is a coupling agent such as alkylsilin on the surface of the inorganic carrier. It is prepared by grafting).

Impregnated activated carbon produces granular or extrudate activated carbon having a high specific surface area with a specific surface area of at least 1,000 m 2 / g and an average particle diameter of 0.05 to 2.00 mm, and is an adsorbent material having adsorption capacity of harmful gases. , For example, by adsorbing an adsorbent such as KI or H ₃ PO ₃ .

The porous inorganic adsorbent is prepared by ion exchange of the inorganic carrier used in the preparation of the organic-inorganic composite adsorbent described above with NH ₄ OH, KOH, Co (NO ₃ ) ₂ , or the like.

The standardized filter medium is formed by using the spinning yarn having the adsorbent bonded to the surface thereof. The filter medium maintains the best breathability of the fluid while minimizing pressure loss while the chemisorption filter of the present invention is installed to be perpendicular to the average flow direction of the fluid. It is a linear or woven net form or screen form in which the fiber filament (spun yarn in the present invention) to which the adsorbent is bound is wound around the frame at regular intervals, as known in the art. Any form such as a mesh may be used.

After completion of the polymerization reaction by the complete aging at 50 ~ 80 ℃ after the molding of the support, the filter body formed of a urethane fiber bonded to the surface of the adsorbent that can adsorb harmful gases is completed.

The outside of the support formed of urethane fibers bonded to the surface of the adsorbent is packaged in a mesh-like support in the form of a net or screen in which organic polymer fibers or inorganic fibers are woven to prepare a chemical adsorption filter for air purification. When the filter medium formed of urethane fibers bonded to the surface of the adsorbent is a mesh, one or both sides of the filter medium may be laminated and packaged with a mesh-like or screen-like mesh support woven with the organic polymer fibers or inorganic fibers. At least one filter medium may be used. Preferably, 3-10 sheets of a support body and a filter body are laminated | stacked and used.

As the organic polymer fibers used to manufacture the mesh support, polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers or polypropylene fibers may be used, and the inorganic fibers may include glass fibers or carbon fibers, but are not limited thereto. It is not.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are intended to illustrate the present invention and do not limit the present invention.

Example 1 Preparation of a Net Chemisorption Filter Attached with Cation Exchange Resin

50 g of isocyanate (prepolymer mixed with a polyol having a molecular weight of 2000 and MDI) and 100 g of a polyol (polyester having a molecular weight of 1500) were mixed with triethylenediamine in an amount of 0.1% by weight of polyol for 5 seconds at 30 DEG C, and then fixed to 1.0 mm in diameter. After spinning in a mold, a spherical strong acid cation exchange resin (Samyang Corp. SK-1B) was spun and sprayed onto a spun yarn, having an average particle diameter of 1.0 mm, and the size was 610 X 610 mm through a continuous process. After forming a mesh filter medium having a pore size of 0.3 X 0.3 mm and then aging at 80 ° C. for 120 minutes, polymerization was completed to prepare a mesh chemisorption filter. At this time, the amount of cation exchange resin consumed was 3 kg / m ² , and the ion exchange capacity was 3.6 equivalent / kg.

Comparative Example 1: Preparation of a net chemisorption filter to which a cation exchange resin was attached with an adhesive

A polyester fiber having a diameter of 1.0 mm and a diameter of 610 X 610 mm, a thickness of 20 mm and a hole spacing of 2.0 X 2.0 mm was formed, and then washed with alcohol to remove impurities. After applying the one-component urethane-based adhesive to the molded net to a thickness of 0.5 mm, the cation exchange resin of Example 1 was attached and then cured at 60 ℃ 120 minutes. At this time, the amount of cation exchange resin consumed was 3 kg / m ² , and the ion exchange capacity was 3.2 equivalent / kg.

Example 2 Preparation of a Net Chemisorption Filter Attached with Anion Exchange Resin

As in Example 1, but instead of the cation exchange resin, an anion exchange resin (Samyang Corporation SA-20) was used to prepare a mesh type chemisorption filter. At this time, the amount of cation exchange resin consumed was 3 kg / m ² , and the ion exchange capacity was 2.7 equivalents / kg.

Comparative Example 2: Preparation of a net chemisorption filter to which an anion exchange resin is attached with an adhesive

A polyester fiber having a diameter of 1.2 mm was 610 × 610 mm, a thickness of 20 mm, and a hole spacing of 2.0 × 2.0 mm was formed and then washed with alcohol to remove impurities. After applying EVA adhesive, which is a hot melt adhesive, to the formed net with a thickness of 0.8 mm, an average particle diameter of 0.6 mm, and a spherical strong alkaline ion exchange resin (Samyang Corporation SA-10AP) was attached and cooled at room temperature. To harden. At this time, the amount of anion exchange resin consumed was 3 kg / m ² , and the ion exchange capacity was 2.3 equivalent / kg.

Example 3 Preparation of Mesh Type Chemisorption Filter with Activated Carbon

In the same manner as in Example 1, instead of a cation exchange resin, activated carbon (domestic acid DT-2000, specific surface area of 1100 m 2 / g, average particle diameter of 0.8 mm) was used to prepare a mesh chemisorption filter. At this time, the amount of adsorbent consumed was 2.1 kg / m ² .

Example  4: Preparation of composite mesh type chemisorption filter with ion exchange resin and zeolite

As in Example 1, but with a cation exchange resin, a zeolite having a surface area of 1,500 m ² / g and an average particle size of 0.5 mm was used as an adsorbent to prepare a network chemisorption filter. At this time, the amount of ion exchange resin required was 1.4 kg / m ² , and the amount of zeolite was 0.7 kg / m ² .

Comparative example  3: Manufacture of mesh type chemisorption filter with ion exchange resin

As in Comparative Example 1, but using a zeolite together with a cation exchange resin as an adsorbent to prepare a network chemisorption filter. At this time, the amount of ion exchange resin required was 1.3 kg / m ² and the amount of zeolite was 0.7 kg / m ² .

Example 5 Preparation of Composite Mesh Type Chemisorption Filter with Activated Carbon and Zeolite

A mesh type chemisorption filter was prepared in the same manner as in Example 3, but using zeolite having a surface area of 1,500 m ² / g and an average particle size of 0.5 mm together with activated carbon as an adsorbent. At this time, the amount of activated carbon consumed was 1.1 kg / m ² , and the amount of zeolite was 0.6 kg / m ² .

Example 6 Preparation of Composite Mesh Type Chemisorption Filter with Filter Media Wrapped with Polyester Fiber Support

A mesh type chemisorption filter having a cation exchange resin of Example 1 was prepared by preparing a mesh support having a diameter of 610 X 610 mm, a thickness of 20 mm, and a pore spacing of 0.3 X 0.3 mm using a polyester fiber having a diameter of 0.5 mm. ) On both sides.

Example 7 Preparation of Composite Mesh Type Chemisorption Filter with Filter Media Wrapped with Carbon Fiber Support

A mesh type chemical adsorption filter (filter) with a cation exchange resin of Example 1 was prepared by preparing a mesh support having a diameter of 610 X 610 mm, a thickness of 20 mm, and a hole spacing of 0.3 X 0.3 mm using carbon fibers having a diameter of 0.3 mm. Both sides of were packed.

Experimental Example: Performance of Chemisorption Filter

The amount of adsorbent is calculated in kg of adsorbent per 1 m ² of filter medium with adsorbent, and the removal rate of noxious gas is 0.5 m / sec of surface wind velocity, 40% relative humidity, and the removal rate at nominal concentrations of ppm to tens of ppb. Shown is the removal rate of ammonia when the adsorbent is a cation exchange resin, the removal rate of sulfur dioxide (SO ₂ ) for anion exchange resin, and the ozone removal rate for activated carbon or an organic-inorganic composite adsorbent.

Sorbent type Adsorbent Input (kg / m ² ) Hazardous Gas Removal Rate (%) Ion exchange capacity (equivalent / m ² ) Example 1 Cation 3 98.2 3.6 Comparative Example 1 Cation 3 87.3 3.2 Example 2 Negative ion 3 96.8 2.7 Comparative Example 2 Negative ion 3 86.2 2.3 Example 3 Activated carbon 2.1 93.6 - Example 4 Cationic zeolite 1.4 0.7 99.2 - Comparative Example 3 Cationic zeolite 1.3 0.7 83.6 - Example 5 Activated carbon zeolite 1.1 0.6 97.0 - Example 6 Cation 3 95.2 - Example 7 Cation 3 95.7 -

In Examples 1, 2 and 4, although the same amount of the same type of adsorbent as Comparative Examples 1, 2 and 3, respectively, it was confirmed that the harmful gas removal rate was significantly increased compared to Comparative Examples 1, 2 and 3. In addition, in the present invention, any of an ion exchange resin, activated carbon, zeolite, or an adsorbent mixture thereof may be used. Is expected to have the effect of preventing the adsorbent from falling off and increasing the durability without much reduction.

As described above, the method of manufacturing the chemical adsorption filter for air purification according to the present invention does not require a process of separately applying an adhesive to bond the adsorbent to the organic or inorganic fiber filament, thereby simplifying the chemical adsorption filter manufacturing process, It is possible to manufacture a stable, long-lasting chemisorption filter due to the functional functional functional coupling of the adsorbent and the urethane fiber without the problem of clogging the active surface of the adsorbent material.

In addition, when the support body made of organic polymer fibers or inorganic fibers is packaged outside the chemisorption filter filter body, the adsorbent is prevented from falling due to the wind speed, which further increases the filter life.

Claims (6)

A reaction injection molding step of mixing the isocyanate and the polyol for 1 to 10 seconds at 25 to 45 ° C., and spinning the polyurethane polymer in which the polymerization reaction is initiated through the spinning nozzle; Applying an adsorbent to the surface of the polyurethane yarn; Chemically bonding an unreacted functional group and an adsorbent on the surface of the yarn; Preparing a filter medium by molding a polyurethane yarn in which the adsorbent is chemically bonded to a surface; And The method of producing a chemical adsorption filter for air purification, characterized in that the adsorbent comprises the step of completing the polymerization of the polyurethane spinning yarn chemically bonded to the surface. The method according to claim 1, Method for producing a chemisorption filter for air purification, characterized in that the average diameter of the spinning yarn is 0.1 ~ 2 mm. The method according to claim 1, The adsorbent is a method of producing a chemical adsorption filter for air purification, characterized in that any one selected from strong acidic or strongly alkaline ion exchange resin, porous organic-inorganic composite adsorbent, impregnated activated carbon and porous inorganic adsorbent. The method according to any one of claims 1 to 3, The method of manufacturing a chemisorption filter for air purification, characterized in that it further comprises the step of wrapping the outside of the filter medium with a mesh-like or screen-like support made of organic polymer fibers or inorganic fibers. The method according to claim 4, The organic polymer fibers are polyester fibers, nylon fibers, acrylic fibers, polyethylene fibers or polypropylene fibers, The inorganic fiber is a manufacturing method of a chemical adsorption filter for air purification, characterized in that the glass fiber or carbon fiber. The chemical adsorption filter for air purification manufactured by the method of any one of Claims 1-3.