Activated carbon deodorization sheet and filter

Abstract

The invention provides an activated carbon deodorization sheet which emits little odor from activated carbon and can effectively remove harmful gas. This activated carbon deodorizing sheet is configured by sandwiching a water-soluble polymer-containing activated carbon between a first base material layer and a second base material layer, the water-soluble polymer-containing activated carbon containing activated carbon and a water-soluble polymer, the molecular weight of a constituent monomer of the water-soluble polymer being 100 g / mol or more, the content of the water-soluble polymer relative to the active carbon is 0.03-1.5 wt%.

Description

Technical Field

[0001] The present invention relates to a deodorant sheet and a filter using the deodorant sheet. Background Art

[0002] Activated carbon has excellent adsorption characteristics for odors such as cigarette odors, and is therefore widely used as a filter raw material for air purifiers, air conditioners with a deodorizing function, and the like.

[0003] However, activated carbon has a peculiar odor, namely activated carbon odor. This activated carbon odor is felt as a damp odor or a powdery odor, is generated by the activated carbon itself, and is enhanced depending on the circumstances. Therefore, although a filter using activated carbon can effectively remove various odors, it also diffuses the activated carbon odor. There are individual differences in the perception of the diffused activated carbon odor, and it is often avoided.

[0004] The activated carbon odor can be suppressed by reducing the amount of activated carbon contained in the filter. However, as the amount of activated carbon is reduced, the removal performance of harmful gases such as toluene decreases. In addition, as a harmful gas remover other than activated carbon, silica gel or the like can also be used, but the removal performance of harmful gases such as toluene decreases. In summary, an activated carbon deodorant sheet with less activated carbon odor and sufficient removal performance for harmful gases such as toluene is preferred.

[0005] Regarding such activated carbon, Patent Document 1 discloses a method of suppressing odor by making fibrous activated carbon contain polyvinyl alcohol. In addition, Patent Document 2 discloses a formed activated carbon obtained by uniformly containing 0.5 to 20% by weight of polyvinyl alcohol in granular activated carbon having a particle size of 6 to 9 mesh (particle diameter 1.9 to 3.3 mm) and then press-forming, and a method for manufacturing the formed activated carbon. In addition, Patent Document 3 discloses an adsorbent comprising: a porous adsorbent containing a hydroxyl group-containing water-soluble polymer; and a binder.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 11-29313

[0009] Patent Document 2: Japanese Patent Laid-Open No. 51-39594

[0010] Patent Document 3: Japanese Patent Laid-Open No. 2021-98177 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] Patent Document 1 does not specify the raw material or form of the activated carbon. In the examples, only fibrous activated carbon is described, and there is no specific description of granular activated carbon. When the granular activated carbon contains 1.0% by weight of polyvinyl alcohol, the pores of the granular activated carbon become blocked, and sufficient removal performance for harmful gases such as toluene cannot be obtained. In addition, since the monomer molecular weight of polyvinyl alcohol is small, it is easily vaporized, and the activated carbon odor containing polyvinyl alcohol is diffused.

[0013] In Patent Document 2, polyvinyl alcohol is used as a binder for granular activated carbon, and there is no description of suppressing activated carbon odor. In addition, since the amount of polyvinyl alcohol is large relative to the surface area of the activated carbon, sufficient removal performance for harmful gases such as toluene cannot be obtained.

[0014] Patent Document 3 does not describe the suppression of activated carbon odor. Granular activated carbon containing 2% by weight or more of a water-soluble polymer with hydroxyl groups cannot obtain sufficient removal performance for harmful gases such as toluene.

[0015] As described above, there has never been an activated carbon deodorizing sheet that can suppress activated carbon odor and other odors while obtaining sufficient removal performance for harmful gases such as toluene.

[0016] Therefore, the present invention has been completed in view of the above problems, and its object is to provide: an activated carbon deodorizing sheet that can suppress activated carbon odor and other odors while having sufficient removal performance for harmful gases such as toluene; and a filter using the same.

[0017] Means for Solving the Problems

[0018] The present invention is as follows.

[0019] (1) An activated carbon deodorizing sheet, characterized by having a first base material layer and a second base material layer, and activated carbon containing a water-soluble polymer sandwiched between the first base material layer and the second base material layer, the activated carbon containing a water-soluble polymer comprising activated carbon and a water-soluble polymer, the molecular weight of the constituent monomer of the water-soluble polymer being 100 g / mol or more, and the content of the water-soluble polymer relative to the activated carbon being 0.03 to 1.5% by weight.

[0020] (2) The activated carbon deodorizing sheet according to (1) above, wherein the toluene removal rate is 75% or more.

[0021] (3) The activated carbon deodorizing sheet according to (1) or (2) above, wherein at least one of the first base material layer and the second base material layer is a polyester spunbond nonwoven fabric.

[0022] (4)The activated carbon deodorizing sheet according to any one of the above (1) to (3), wherein the activated carbon containing a water-soluble polymer is fixed to at least one of the first base material layer and the second base material layer by adhesion.

[0023] (5)A filter using the activated carbon deodorizing sheet according to any one of the above (1) to (4).

[0024] Advantages of the Invention

[0025] According to the present invention, there can be provided: an activated carbon deodorizing sheet having sufficient removal performance for harmful gases such as toluene while suppressing activated carbon odor and other odors; and a filter using the same. Detailed Embodiments

[0026] Hereinafter, the present invention will be specifically described. However, the present invention is not limited to the following content, and can also be appropriately modified and implemented within the scope that can conform to the gist described above and below, and they are all included in the technical scope of the present invention.

[0027] The activated carbon deodorizing sheet of the present invention is constituted by sandwiching activated carbon containing a water-soluble polymer between a first base material layer and a second base material layer. The activated carbon containing a water-soluble polymer contains activated carbon and a water-soluble polymer. In this activated carbon containing a water-soluble polymer, 0.03 to 1.5% by weight of a water-soluble polymer having a monomer molecular weight of 100 g / mol or more is contained relative to the weight of the activated carbon.

[0028] (Water-soluble polymer)

[0029] In the activated carbon deodorizing sheet of the present invention, the monomer molecular weight of the water-soluble polymer is preferably 100 g / mol or more. When the monomer molecular weight of the water-soluble polymer is less than 100 g / mol, it is easily vaporized, so the odor of the water-soluble polymer is easily diffused. In order to suppress not only the activated carbon odor but also the odor generated by the filter, a water-soluble polymer that is not easily vaporized is preferred. In addition, when the monomer molecular weight is less than 100 g / mol, the pores of the activated carbon are likely to be blocked, and it may be difficult to exhibit deodorizing characteristics and adsorption characteristics.

[0030] The upper limit of the monomer molecular weight of the water-soluble polymer is not particularly limited. For example, it is preferably 600 g / mol or less, more preferably 550 g / mol or less, and further preferably 500 g / mol or less.

[0031] In the activated carbon deodorizing tablet of the present invention, with respect to 100% by weight of the activated carbon, the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer is preferably 0.03 to 1.5% by weight, more preferably 0.05 to 1.0% by weight. If it is in this range, the activated carbon odor can be effectively suppressed, and the adsorption characteristics can be exhibited. When the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer is less than 0.03% by weight with respect to 100% by weight of the activated carbon, the activated carbon odor diffusing from the activated carbon cannot be effectively suppressed. On the contrary, when the content exceeds 1.5% by weight, due to the reduction of the specific surface area of the activated carbon and the blockage of the pores, it is difficult to exhibit the deodorizing characteristics and adsorption characteristics.

[0032] Examples of the water-soluble polymer having a monomer molecular weight of 100 g / mol or more used in the present invention include polyvinylpyrrolidone, carboxymethyl polymer, guar gum, etc. As the carboxymethyl polymer, for example, sodium carboxymethyl cellulose can be mentioned. However, these are merely examples and are not limited thereto.

[0033] The molecular weight of the constituent monomers of the water-soluble polymer used in the present invention can be obtained by calculation based on the structural formula. In the calculation, the atomic weights are C: 12, H: 1, O: 16, N: 14, Na: 23.

[0034] When the water-soluble polymer contains a plurality of constituent monomers, the molecular weight of each constituent monomer of the water-soluble polymer is preferably in the above range. By making the molecular weight of each constituent monomer in the above range, the effect of the activated carbon deodorizing tablet of the present invention can be exhibited. Alternatively, when the water-soluble polymer contains a plurality of constituent monomers, the molecular weight of the constituent monomers of the water-soluble polymer can be the weighted average of the molecular weights of the constituent monomers.

[0035] Regarding the molecular weight of the constituent monomers of the water-soluble polymer, for example, in the case of polyvinylpyrrolidone, the structural formula of the monomer is C 6 H 9 NO, so the molecular weight of the constituent monomer is 111 g / mol. In the case of sodium carboxymethyl cellulose, the structural formula is C 6 H 7 O 5 R 3 (R = H or R = CH 2 COONa), so the molecular weight of the constituent monomer is 162 to 402 g / mol. In the case of guar gum, the structural formula is C 18 H 30 O 15, so the molecular weight of the monomer that makes up the polymer is 486 g / mol. The molecular weight of the monomer that makes up these water-soluble polymers is 100 g / mol or more. Additionally, for example, in the case where the water-soluble polymer is polyvinyl alcohol, polyvinyl alcohol contains vinyl groups bonded to hydroxyl groups (C 2 H 4 O, molecular weight 44 g / mol) and vinyl groups bonded to acetate groups (C 4 H 6 O 2 , molecular weight 86 g / mol). Therefore, the molecular weights of the monomers that make up polyvinyl alcohol are 44 g / mol and 86 g / mol. Thus, the molecular weight of the monomer that makes up polyvinyl alcohol is 100 g / mol or less.

[0036] The solubility of the water-soluble polymer used in the present invention is not particularly limited, and it is preferably easily soluble in water at room temperature. When the solubility is low, the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer is small, and the activated carbon odor cannot be suppressed. In addition, when the activated carbon is coated with an organic solvent or the like, since the odor of the organic solvent is felt due to the activated carbon, it is not preferred.

[0037] In the present invention, the viscosity of the aqueous solution of the water-soluble polymer is not particularly limited, but in order to uniformly coat the surface of the activated carbon and the deep inside of the pores, and to prevent granulation of the activated carbon caused by viscosity, a low viscosity is preferred. Specifically, regarding the viscosity of the aqueous solution of the water-soluble polymer, the value measured at 20 °C for a 1% aqueous solution of the water-soluble polymer is preferably 500 mPa·s (1% aq - 20 °C) or less, more preferably 250 mPa·s (1% aq - 20 °C) or less, and further preferably 50 mPa·s (10% aq - 20 °C) or less. The lower limit of the viscosity of the aqueous solution of the water-soluble polymer is not particularly limited, and for example, it can be set to 1 mP·s or more, 5 P·s or more, 10 P·s or more. For example, it can be measured using a rotational viscometer according to JIS Z 8803. Regarding the measurement method of the viscosity of the aqueous solution of the water-soluble polymer, there is no particular limitation.

[0038] In the activated carbon deodorizing sheet of the present invention, by uniformly coating the water-soluble polymer on the entire surface of the activated carbon, it can have sufficient removal performance for harmful gases such as toluene.

[0039] (Activated carbon)

[0040] In the present invention, the raw material of the activated carbon is not particularly limited. For example, common activated carbons such as coconut shell-based activated carbon, coal-based activated carbon, wood-based activated carbon, synthetic resin-based activated carbon, and pitch-based activated carbon can be cited, and coconut shell-based activated carbon is preferred. Compared with other raw materials, the coconut shell-based activated carbon has a higher ratio of small pores and less ash as an impurity. That is, since the pores of the coconut shell-based activated carbon are small, the intermolecular force between the adsorbed odor molecules and the pore walls effectively acts, and it is difficult for the adsorbed odor molecules to desorb.

[0041] In the present invention, the shape of the activated carbon is preferably granular. As long as it is granular, there is no particular limitation, and it can be powdery, irregularly crushed shape, or it can also be any one of the shapes formed into fibrous, cylindrical, spherical, etc. The crushed shape is preferred because the packing density becomes smaller and the ventilation resistance is reduced. The crushed activated carbon can be obtained by mechanically crushing coconut shell activated carbon with a ball mill, crusher, etc.

[0042] In the present invention, the average particle size of the activated carbon is not particularly limited, preferably 100 μm or more, more preferably 200 to 1000 μm. When the average particle size is less than 100 μm, there is a possibility of easy shedding and scattering. In the case where the average particle size exceeds 1000 μm, the processing of the activated carbon deodorizing sheet becomes significantly difficult. Regarding the average particle size of the activated carbon, the mass average diameter based on the JIS K1474 activated carbon test method is used as the average particle size.

[0043] In the present invention, the weight per unit area of the activated carbon is not particularly limited, preferably 30 g / m 2 or more, more preferably 40 g / m 2 or more. If it is less than 30 g / m 2 , the adsorption performance is lacking.

[0044] In the present invention, the specific surface area of the activated carbon is not particularly limited, and in the measurement using the BET method, the specific surface area is preferably 100 m 2 / g to 2000 m 2 / g, more preferably 200 m 2 / g to 2000 m 2 / g. When the specific surface area is less than 100 m 2 / g, the adsorption performance is lacking, and when it is greater than 2000 m 2 / g, the strength of the material becomes weak.

[0045] (Manufacturing method)

[0046] In the present invention, the method for manufacturing the activated carbon containing a water-soluble polymer is not particularly limited, and examples thereof include: a method of preparing an aqueous solution of a water-soluble polymer and spraying the aqueous solution onto the activated carbon; or a method of impregnating the activated carbon in an aqueous solution of a water-soluble polymer. In order to uniformly contain the water-soluble polymer on the entire surface of the activated carbon, the spraying method is more preferable. Since the surface is coated with the water-soluble polymer, the diffusion of the activated carbon odor is suppressed.

[0047] The water in the aqueous solution of the water-soluble polymer contained in the activated carbon containing a water-soluble polymer is preferably removed by a usual drying method. The drying temperature is not particularly limited, and in order to dry it in a short time and prevent ignition of the activated carbon containing a water-soluble polymer, it is preferably 30°C or higher and lower than 100°C, more preferably 40°C or higher and 90°C or lower, and further preferably 50°C or higher and 80°C or lower. After drying, subtract the weight (Mi) of the activated carbon before containing the water-soluble polymer from the weight (Mo) of the activated carbon containing a water-soluble polymer, and divide by the weight (Mi) of the activated carbon before containing the water-soluble polymer. The content (% by weight) of the water-soluble polymer contained in the activated carbon containing a water-soluble polymer can be calculated based on the value obtained thereby (Equation 1).

[0048] Content (% by weight) of the water-soluble polymer contained in the activated carbon containing a water-soluble polymer = (Mo - Mi) / Mi × 100 (Equation 1)

[0049] In the present invention, the method for supporting the activated carbon containing a water-soluble polymer on the first substrate layer and / or the second substrate layer is not particularly limited. For example, a binder can be used. Therefore, hereinafter, the case of using a binder will be described. The binder preferably contains a thermoplastic resin and may be composed of a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins, polyamide resins, synthetic rubber resins, polyester resins, ethylene-acrylic copolymer resins, etc. The composition of the binder is not particularly limited.

[0050] The shape of the thermoplastic powder resin used in the binder is not particularly limited, and examples thereof include granular, spherical, crushed, fibrous, etc. Of course, two or more kinds can also be used in combination. Further, even in the case of using activated carbon supporting a chemical agent or the first substrate layer and / or the second substrate layer supporting a chemical agent, if it is this formulation, the binder becomes temporarily adhered to the surface of the activated carbon from the time of mixing in the dry state, so even if the chemical agents have different properties, it is possible to avoid the situation of mutual interference in the subsequent sheet forming process, and thus sufficient effects can be exerted. Considering the environmental temperature when using the activated carbon deodorizing sheet, etc., the melting point of the binder is preferably 80°C or higher, more preferably 90°C or higher.

[0051] In the present invention, the shape and size of the thermoplastic powder resin used in the binder are not particularly limited, and it is preferably granular with an average particle diameter of 100 to 300 μm. If the granular binder is less than 100 μm, the adhesion force based on van der Waals force and electrostatic force acts between the granular adsorbent material and the binder, and the binder cannot actively contact the substrate layer, and sufficient peel strength cannot be obtained. On the other hand, if it exceeds 300 μm, the thickness of the filter material becomes larger, and the structural resistance during the production of the filter increases, which is not preferably in practical use. Regarding the average particle diameter of the binder, the D50 median diameter is used as the average particle diameter by using a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation).

[0052] The coating method of the binder is not particularly limited. It is also possible to mix activated carbon containing a water-soluble polymer with the binder and uniformly disperse it on the substrate. It is also possible to cite: a method of spraying and coating the molten binder together with hot air using a hot melt gun, etc.

[0053] In the activated carbon deodorizing sheet of the present invention, the binder is preferably used in an amount of 10 to 80% by weight, more preferably 20 to 60% by weight, based on the activated carbon. If it is within the range, a deodorizing filter material excellent in adhesion to the first substrate layer and / or the second substrate layer, pressure loss, and deodorizing performance can be obtained.

[0054] (Activated carbon deodorizing sheet)

[0055] In the activated carbon deodorizing sheet of the present invention, activated carbon containing a water-soluble polymer is sandwiched between the first substrate layer and the second substrate layer. Hereinafter, for these substrate layers, the layer disposed on the upstream side in the ventilation direction during air purification is referred to as the upstream layer, and the layer disposed on the downstream side in the ventilation direction during air purification is referred to as the downstream layer. When it is not necessary to distinguish between the upstream layer and the downstream layer, they are collectively referred to as the substrate. The substrate can be a fibrous structure such as a non-woven fabric or a woven fabric.

[0056] In the present invention, the substrate is not particularly limited and is a sheet-like structure formed of fibers such as polyolefin-based fibers, polyester-based fibers, polyamide-based fibers, and polyurethane-based fibers. The manufacturing method of the substrate is not particularly limited, and the meltblowing method, the thermal bonding method, the airlaid method, the needling method, the hydroentangling method, the spunbond method, and the chemical bonding method can be used alone or in combination.

[0057] In the present invention, the substrate can carry a chemical agent. The chemical agent carried is not particularly limited.

[0058] The material of the upstream layer in the present invention is not particularly limited, and a polyester spunbond non-woven fabric as a polyester-based fiber structure is preferred. This is because, when the activated carbon deodorizing sheet of the present invention is used as a filter material for an air purifier, it is preferably rigid from the viewpoint of pleating processing.

[0059] In the present invention, the rigidity in the MD direction of the upstream layer is not particularly limited. When used as a filter material for an air purifier, from the viewpoint of shape retention during pleating, it is preferably 10 mg or more, more preferably 50 mg or more. The rigidity in the MD direction can be measured according to JIS L-1096 Method A (Gurley method).

[0060] In the present invention, the fiber diameter of the constituent fibers of the upstream layer is not particularly limited. However, if the average fiber diameter of the constituent fibers is less than 1 μm, the voids between the fibers also become narrow, dust in the air accumulates on the layer, and the ventilation resistance increases sharply. If the average fiber diameter of the constituent fibers is greater than 100 μm, the activated carbon flies out or falls off. Therefore, the average fiber diameter of the constituent fibers of the base material of the upstream layer is preferably 1 μm or more and 100 μm or less, more preferably 3 μm or more and 90 μm or less, and further preferably 5 μm or more and 80 μm or less. The average fiber diameter is calculated as follows: Take a scanning electron microscope photograph of the layer surface (magnification 100 - 1000 times), and calculate the average value with n = 30 from this photograph.

[0061] In the present invention, the material of the downstream layer is not particularly limited, and polypropylene meltblown nonwoven fabric as a polyolefin-based fiber structure is preferred. This is because when the activated carbon deodorizing sheet of the present invention is used as a filter material for an air purifier, it has dust collection performance in addition to deodorizing performance. The polypropylene meltblown nonwoven fabric is preferably electretized, and the electretization method is not limited.

[0062] In the present invention, the average fiber diameter of the constituent fibers of the downstream layer is not particularly limited, but considering the falling off of the activated carbon, it is preferably 1 - 30 μm. If the average fiber diameter of the constituent fibers is less than 1 μm, the ventilation resistance is high, and if it is greater than 30 μm, the falling off of the activated carbon occurs. The average fiber diameter is calculated as follows: Take a scanning electron microscope photograph of the layer surface (magnification 100 - 1000 times), and calculate the average value with n = 30 from this photograph.

[0063] In the present invention, the basis weight of the base material is not particularly limited, and it is preferably 15 - 100 g / m 2 and more preferably 20 - 80 g / m 2 . If the basis weight of the base material is less than 15 g / m 2 , the leakage of the activated carbon and the binder increases. If the basis weight exceeds 100 g / m 2 , the sheet thickness becomes large, and the structural resistance during pleating becomes large. Regarding the basis weight of the base material, it can be measured as follows. Use a 200 mm × 200 mm specimen, place it in a constant temperature bath at 80 °C for 30 minutes, and then place it in a desiccator (desiccant: silica gel) for 30 minutes. Then take it out and measure it with a chemical balance with a sensitivity of 10 mg, and convert it to per 1 m 2The weight.

[0064] In the present invention, the thickness of the base material is preferably 0.1 to 3.0 mm. If the thickness is less than 0.1 mm, there is a concern about omission and shedding of activated carbon when considering uneven weight per unit area. If the thickness exceeds 3.0 mm, the thickness of the entire sheet becomes too large, and when forming a pleated unit, the structural resistance becomes large. As a result, the ventilation resistance of the entire unit becomes too high, and there are practical problems. The thickness can be measured as follows. Using a specimen of φ75 mm, it is measured with a dial thickness gauge. The size of the measuring head is set to φ50 mm, and the measuring load is set to 2.94 N.

[0065] In the activated carbon deodorizing sheet of the present invention, other adsorbents such as silica gel can also be sandwiched between the upstream layer and the downstream layer. The types and shapes of other adsorbents are not limited. Of course, two or more kinds of adsorbents can also be used in combination.

[0066] In the manufacture of the activated carbon deodorizing sheet of the present invention, as a method of sandwiching activated carbon containing a water-soluble polymer between the upstream layer and the downstream layer and forming a sheet, there can be mentioned an inter-roll hot pressing method and a flat lamination method in which it is sandwiched between flat tropical conveyors on the upper and lower sides. The latter is more preferable in order to form a more uniform thickness and bonding state. In the case where it is desired to prevent the binder from covering the activated carbon containing the water-soluble polymer, there can also be mentioned a method in which a binder is coated on the upstream layer and the downstream layer with a hot melt gun or the like, and then the activated carbon containing the water-soluble polymer is scattered and pressed with one or more sets of rollers to bond. By combining the above base material with the above sheet forming method, excessive adhesion between the activated carbons containing the water-soluble polymer can be suppressed, and at the same time, a sufficient bonding strength with the base material in practical use can be obtained. In addition, the sheet forming method is not limited to the above method.

[0067] The activated carbon deodorizing sheet of the present invention can be used in the form of a filter or a filter unit by combining it with a monomer or other filter materials, frame materials, etc. after being made into a required size. A filter having the activated carbon deodorizing sheet of the present invention can be subjected to, for example, pleating processing, mounting processing on a support, a frame, etc. In addition, the filter of the present invention can also be formed by combining other materials with the activated carbon deodorizing sheet of the present invention. The filter of the present invention is installed, for example, in an air conditioner, an air purifier, an automobile, etc., and is used to purify the air in a space such as the air in a room including public places and the air in a vehicle.

[0068] This application claims the benefit of priority based on Japanese Patent Application No. 2023-053422 filed on March 29, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-053422 filed on March 29, 2023 are incorporated herein by reference.

[0069] Examples

[0070] Examples are shown below to more specifically illustrate the present invention, but the present invention is not limited to the content described in the examples. First, the measurement methods and evaluation methods for the sensory evaluation of activated carbon odor and the toluene removal performance evaluation of the activated carbon deodorant sheets used in the examples and comparative examples will be described.

[0071] 1. Sensory evaluation

[0072] Insert the single-board test sample into a column with an effective area of 36 cm 2 for configuration. In an atmosphere of 25°C and 50% relative humidity, use an electric blower (SF-50-R3A3 manufactured by Showa Electric Co., Ltd.) to supply air with a wind speed of 10 cm / sec. Bring the nose close to the column outlet downstream of the filter material and evaluate using a 6-level odor intensity representation method. Define odor intensity 0 as "odorless", odor intensity 1 as "detection threshold", odor intensity 2 as "recognition threshold", odor intensity 3 as "easily perceivable odor", odor intensity 4 as "strong odor", and odor intensity 5 as "intense odor". Evaluate the odor by 6 subjects and calculate the average value of the odor intensity. The water-soluble polymer content when the odor intensity of the activated carbon containing the water-soluble polymer reaches 1 / 2 or less compared to the odor intensity of the activated carbon without the water-soluble polymer is set as the content of the water-soluble polymer having an odor reduction effect. For subjects who feel an odor intensity of 2 or more, confirm whether the activated carbon odor has deteriorated. If more than half of the subjects feel the odor has deteriorated, it is considered that the odor of the water-soluble polymer has spread.

[0073] 2. Toluene removal performance evaluation

[0074] Insert the single-board test sample into a column with an effective area of 36 cm 2 for configuration. In an atmosphere of 25°C and 50% relative humidity, ventilate 10 ppm of toluene gas to the test filter material at a wind speed of 10 cm / sec. After ventilation for 1 minute, measure the concentrations upstream and downstream of the filter material using a hydrocarbon meter (VMS-1000F) manufactured by Shimadzu Corporation, and express the removal rate (η) as the percentage of the value (Ci) obtained by dividing the value obtained by subtracting the downstream gas concentration from the upstream gas concentration (Co) by the upstream gas concentration (Equation 2). The measurement is carried out using a filter material single-board sample cut into 6 cm × 6 cm. If the deviation of the toluene removal rate of the activated carbon containing the water-soluble polymer from that of the activated carbon without the water-soluble polymer is within 10%, it is considered to have sufficient toluene removal performance.

[0075] Toluene removal performance η(%) = [1 - (Co / Ci)] × 100 (Equation 2)

[0076] <Example 1>

[0077] Granular activated carbon (GNC50 / 80 with a pore volume of 0.44 cc / g, manufactured by Osaka Gas Chemicals Co., Ltd.) and polyvinylpyrrolidone K-90 (product code P0473, manufactured by Tokyo Chemical Industry Co., Ltd.) as a water-soluble polymer were used. The monomer structural formula of this water-soluble polymer is C 6 H 9 NO, and the monomer molecular weight is 111 g / mol. In order to make the activated carbon uniformly and entirely contain the water-soluble polymer, the amount of the water-soluble polymer aqueous solution was made equal to the pore volume of the activated carbon. The concentration of the water-soluble polymer aqueous solution was adjusted so that the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer became 0.05% by weight, and it was sprayed onto the activated carbon. After spraying, the moisture was removed with a hot air dryer, and the content of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer was measured.

[0078] The above-mentioned activated carbon containing the water-soluble polymer was mixed with a thermoplastic powder resin (PR-2030H, manufactured by SEISHIN ENTERPRISE CO., LTD.) as a binder to prepare a mixed powder with a weight ratio of activated carbon to binder of 1:0.3. The base material of the upstream layer was set as a polyester spunbond nonwoven fabric with a fiber diameter of 40 - 50 μm and a unit area weight of 40 g / m 2 and the base material of the downstream layer was set as a polypropylene meltblown nonwoven fabric with a fiber diameter of 2 - 10 μm and a unit area weight of 20 g / m 2 The mixed powder was uniformly dispersed on one base material in such a way that the unit area weight of the activated carbon (before containing the water-soluble polymer) became 44 g / m 2 , clamped with another base material, and hot-pressed to obtain an activated carbon deodorizing sheet.

[0079] <Example 2>

[0080] Sodium carboxymethyl cellulose (product code 020-14515, manufactured by Kishida Chemical Co., Ltd.) was used as the water-soluble polymer. The monomer structural formula of this water-soluble polymer is C 6 H 7 O 5 R 3 (R = H or CH 2 COONa), and the monomer molecular weight is 162 - 402 g / mol. Except for this, the activated carbon deodorizing sheet was obtained in the same manner as in Example 1.

[0081] <Example 3>

[0082] Guar gum (product code G0478, manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the water-soluble polymer. The monomer structural formula of this water-soluble polymer is C18 H 30 O 15 The monomer molecular weight is 486 g / mol. Other than that, an activated carbon deodorizing sheet was obtained in the same manner as in Example 1.

[0083] <Example 4>

[0084] The concentration of the aqueous solution of the water-soluble polymer was adjusted so as to obtain an activated carbon containing 1.0% by weight of polyvinylpyrrolidone K-90 (product code P0473, manufactured by Tokyo Chemical Industry Co., Ltd.) as a water-soluble polymer with respect to 100% by weight of the activated carbon. Other than that, an activated carbon deodorizing sheet was obtained in the same manner as in Example 1.

[0085] <Example 5>

[0086] The concentration of the aqueous solution of the water-soluble polymer was adjusted so as to obtain an activated carbon containing 1.0% by weight of sodium carboxymethyl cellulose (product code 020-14515, manufactured by Kishida Chemical Co., Ltd.) as a water-soluble polymer with respect to 100% by weight of the activated carbon. Other than that, an activated carbon deodorizing sheet was obtained in the same manner as in Example 2.

[0087] <Example 6>

[0088] The concentration of the aqueous solution of the water-soluble polymer was adjusted so as to obtain an activated carbon containing 1.0% by weight of guar gum (product code G0478, manufactured by Tokyo Chemical Industry Co., Ltd.) as a water-soluble polymer with respect to 100% by weight of the activated carbon. Other than that, an activated carbon deodorizing sheet was obtained in the same manner as in Example 3.

[0089] <Example 7>

[0090] Instead of spreading the activated carbon containing the water-soluble polymer and the thermoplastic powder resin as a binder in the form of a mixed powder, an olefin resin with a softening point of 120 °C was coated on the upstream layer and the downstream layer, and then the activated carbon containing 0.05% by weight of polyvinylpyrrolidone K-90 (product code P0473, manufactured by Tokyo Chemical Industry Co., Ltd.) as a water-soluble polymer with respect to 100% by weight of the activated carbon was spread, and hot pressing was performed. Other than that, an activated carbon deodorizing sheet was obtained in the same manner as in Example 1.

[0091] <Example 8>

[0092] The concentration of the aqueous solution of the water-soluble polymer was adjusted so that the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer was 1.0% by weight relative to 100% by weight of the activated carbon. Other than this, the activated carbon deodorizing sheet was obtained in the same manner as in Example 7.

[0093] <Example 9>

[0094] Instead of spraying the activated carbon containing the water-soluble polymer and the thermoplastic powder resin as a binder in the form of a mixed powder, an olefin resin with a softening point of 120 °C was coated on the upstream layer and the downstream layer, and then activated carbon containing 0.05% by weight of guar gum (product code G0478, manufactured by Tokyo Chemical Industry Co., Ltd.) as the water-soluble polymer was sprayed. After that, hot pressing was carried out. Other than this, the activated carbon deodorizing sheet was obtained in the same manner as in Example 3.

[0095] <Example 10>

[0096] The concentration of the aqueous solution of the water-soluble polymer was adjusted so that the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer was 1.0% by weight relative to 100% by weight of the activated carbon. Other than this, the activated carbon deodorizing sheet was obtained in the same manner as in Example 9.

[0097] <Comparative Example 1>

[0098] Granular activated carbon (GNC50 / 80, manufactured by Osaka Gas Chemicals Co., Ltd., pore volume 0.44 cc / g) and a thermoplastic powder resin as a binder (PR-2030H, manufactured by SEISHIN Enterprise Co., Ltd.) were made into a mixed powder with a weight ratio of 1:0.3. The base material of the upstream layer was a polypropylene spunbond nonwoven fabric with a fiber diameter of 40 - 50 μm and a basis weight of 50 g / m 2 and the base material of the downstream layer was a polypropylene meltblown nonwoven fabric with a fiber diameter of 2 - 10 μm and a basis weight of 20 g / m 2 The mixed powder was sprayed onto one base material so that the basis weight of the activated carbon became 44 g / m 2 and then clamped with the other base material and hot pressed to obtain the activated carbon deodorizing sheet.

[0099] <Comparative Example 2>

[0100] Polyvinyl alcohol KH-17 (manufactured by Mitsubishi Chemical Corporation) was used as the water-soluble polymer. The monomers of this water-soluble polymer are vinyl groups bonded with hydroxyl groups (C 2 H 4 O) and vinyl groups bonded with acetate groups (C 4 H 6 O 2(0) For these two types, the molecular weights of the monomers are 44 g / mol and 86 g / mol respectively. The concentration of the aqueous solution of the water-soluble polymer was adjusted such that the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer was 0.05% by weight based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Example 1.

[0101] <Comparative Example 3>

[0102] The concentration of the aqueous solution of the water-soluble polymer was adjusted such that the amount of the water-soluble polymer contained in the activated carbon containing the water-soluble polymer was 1.0% by weight based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Comparative Example 2.

[0103] <Comparative Example 4>

[0104] The concentration of the aqueous solution of the water-soluble polymer was adjusted to obtain an activated carbon containing a water-soluble polymer such that the activated carbon contained 0.01% by weight of polyvinylpyrrolidone K-90 (product code P0473, manufactured by Tokyo Chemical Industry Co., Ltd.) as the water-soluble polymer based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Example 1.

[0105] <Comparative Example 5>

[0106] The concentration of the aqueous solution of the water-soluble polymer was adjusted to obtain an activated carbon containing a water-soluble polymer such that the activated carbon contained 0.01% by weight of sodium carboxymethyl cellulose (product code 020-14515, manufactured by Kishida Chemical Co., Ltd.) as the water-soluble polymer based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Example 2.

[0107] <Comparative Example 6>

[0108] The concentration of the aqueous solution of the water-soluble polymer was adjusted to obtain an activated carbon containing a water-soluble polymer such that the activated carbon contained 0.01% by weight of guar gum (product code G0478, manufactured by Tokyo Chemical Industry Co., Ltd.) as the water-soluble polymer based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Example 3.

[0109] <Comparative Example 7>

[0110] The concentration of the aqueous solution of the water-soluble polymer was adjusted to obtain an activated carbon containing a water-soluble polymer such that the activated carbon contained 2.0% by weight of polyvinylpyrrolidone K-90 (product code P0473, manufactured by Tokyo Chemical Industry Co., Ltd.) as the water-soluble polymer based on 100% by weight of the activated carbon. Except for this, the activated carbon deodorizing tablets were obtained in the same manner as in Example 1.

[0111] <Comparative Example 8>

[0112] The concentration of the aqueous solution of the water-soluble polymer was adjusted so that the activated carbon containing the water-soluble polymer contained 2.0% by weight of sodium carboxymethyl cellulose (product code 020-14515, manufactured by Kishida Chemical Co., Ltd.) as the water-soluble polymer with respect to 100% by weight of the activated carbon. Except for this, the activated carbon deodorant sheet was obtained in the same manner as in Example 2.

[0113] <Comparative Example 9>

[0114] The concentration of the aqueous solution of the water-soluble polymer was adjusted so that the activated carbon containing the water-soluble polymer contained 2.0% by weight of guar gum (product code G0478, manufactured by Tokyo Chemical Industry Co., Ltd.) as the water-soluble polymer with respect to 100% by weight of the activated carbon. Except for this, the activated carbon deodorant sheet was obtained in the same manner as in Example 3.

[0115] Sensory evaluation and toluene removal performance evaluation were performed on the activated carbon deodorant sheets of Examples 1 to 10 and Comparative Examples 1 to 9 obtained above. Table 1 shows the results of the activated carbon deodorant sheets of Examples 1 to 10, and Table 2 shows the results of the activated carbon deodorant sheets of Comparative Examples 1 to 9.

[0116] [Table 1]

[0117]

[0118] [Table 2]

[0119]

[0120] As can be seen from Table 1, in Examples 1 to 10, the activated carbon containing the water-soluble polymer containing 0.03 to 1.5% by weight of the water-soluble polymer having a monomer molecular weight of 100 g / mol or more with respect to 100% by weight of the activated carbon had a reduced activated carbon odor and the odor of the water-soluble polymer did not spread, and had sufficient toluene removal performance. It was also found that the method of spraying the binder did not affect the reduction of the activated carbon odor, the odor diffusion of the water-soluble polymer, and the toluene removal performance.

[0121] As can be seen from Table 2, the activated carbon deodorizing sheet using the activated carbon without water-soluble polymer in Comparative Example 1 has sufficient toluene removal performance, but an activated carbon odor is felt. In addition, it can be seen that for the activated carbon deodorizing sheet of Comparative Example 2 using activated carbon containing 0.05% by weight of a water-soluble polymer having a monomer molecular weight of less than 100 g / mol based on 100% by weight of the activated carbon, the activated carbon odor is suppressed and it has sufficient toluene removal performance, but the odor of the water-soluble polymer diffuses. Further, it can be seen that for the activated carbon deodorizing sheet of Comparative Example 3 using activated carbon containing 1.0% by weight of a water-soluble polymer having a monomer molecular weight of less than 100 g / mol based on 100% by weight of the activated carbon, the activated carbon odor is suppressed, but the odor of the water-soluble polymer diffuses and the toluene removal performance decreases.

[0122] In addition, as can be seen from Table 2, for the activated carbon deodorizing sheets of Comparative Examples 4 to 6 using activated carbon containing 0.01% by weight of a water-soluble polymer having a monomer molecular weight of 100 g / mol or more based on 100% by weight of the activated carbon, the effect of suppressing the activated carbon odor is insufficient, but the odor of the water-soluble polymer does not diffuse and it has sufficient toluene removal performance.

[0123] In addition, as can be seen from Table 2, for the activated carbon deodorizing sheets of Comparative Examples 7 to 9 using activated carbon containing 2.0% by weight of a water-soluble polymer having a monomer molecular weight of 100 g / mol or more based on 100% by weight of the activated carbon, the activated carbon odor is reduced and the odor of the water-soluble polymer does not diffuse either, but the toluene removal performance decreases.

[0124] Industrial Applicability

[0125] According to the present invention, it is possible to provide an activated carbon deodorizing sheet with less activated carbon odor and other odors and having sufficient removal performance for harmful gases such as toluene. The activated carbon deodorizing sheet of the present invention can be effectively used in filters for air purifiers, air conditioners, etc., and can make a great contribution to the industry.

Claims

1. An activated carbon deodorizing sheet, characterized in that: The invention comprises a first substrate layer, a second substrate layer, and activated carbon containing a water-soluble polymer sandwiched between the first substrate layer and the second substrate layer. The activated carbon containing water-soluble polymer comprises activated carbon and water-soluble polymer, The molecular weight of the monomers constituting the water-soluble polymer is greater than 100 g / mol, The content of the water-soluble polymer is 0.03 wt % to 1.5 wt % relative to 100 wt % of the activated carbon.

2. The activated carbon deodorizing sheet according to claim 1, characterized in that: The toluene removal rate is more than 75%.

3. The activated carbon deodorizing sheet according to claim 1, characterized in that: At least one of the first substrate layer and the second substrate layer is a polyester spunbond nonwoven fabric.

4. The activated carbon deodorizing sheet according to claim 1, characterized in that: The activated carbon containing the water-soluble polymer is fixed to at least one of the first substrate layer and the second substrate layer by bonding. 5 . A filter comprising the activated carbon deodorizing sheet according to claim 1 .

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