Molded body for water purification

Abstract

The present invention addresses the problem of developing a molded article for water purification use in which activated carbon fibers are used and which sustainably exhibits high water purification performance and little pressure loss. The present invention also addresses the problem of providing a molded article which rarely loses the shape thereof in spite of the fact that activated carbon fibers are used and which exhibits excellent effects when used for water purification purposes.　The molded article is produced by blending activated carbon with the fibrous binder in such a manner that the amount of the fibrous binder becomes 0.3 to 20 parts by weight relative to 100 parts by weight of the activated carbon. The activated carbon contains activated carbon fibers in an amount of 5 parts by weight or more. Activated carbon fibers having an (average fiber length) / (average fiber diameter) ratio of 5 to 40 are used.

Description

[Technical Field]

[0001] The present disclosure relates to a molded body, and more particularly to a molded body containing activated carbon and suitable for water purification. [Background technology]

[0002] Water purification filters are used to purify tap water, etc. Water purification filters have a variety of uses, but in the case of drinking water, they are sometimes used to remove residual chlorine, unpleasant odor components, and the like.

[0003] It is known that powdered activated carbon and activated carbon fiber, which have adsorption properties, are used as water purification filters. Activated carbon fiber can be prepared with excellent adsorption properties, making it suitable as a water purification filter material with high water purification capacity. However, activated carbon fiber itself generally tends to be more brittle and crumble easily than other synthetic fibers, and it can be difficult to maintain its shape in the presence of water flow. Therefore, activated carbon fiber has been processed into various shapes for use.

[0004] As a filter using activated carbon fiber, for example, (1) a filter in which an activated carbon fiber layer is wound around a hollow cylinder to form a thick wall portion, and a water-permeable nonwoven fabric is wound around each of the inner and outer peripheral surfaces, and both ends are further fixed with solid paraffin (e.g., Patent Document 1); (2) a water purification filter in which the inner and outer peripheral layers of a cylinder are each made of nonwoven fabric, and the layer between the inner and outer layers is made of a mixed paper made of activated carbon fiber and heat-fusible fiber, and both ends of the cylinder are fixed with a thermoplastic resin (e.g., Patent Document 2); and (3) an activated carbon sheet for water purification, which is a wet-laid paper sheet containing fibrous activated carbon, heat-fusible fiber, etc., and is thermally processed (e.g., Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 6-72619 [Patent Document 2] Japanese Patent Application Publication No. 9-239214 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-110228 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, activated carbon fiber has been used in various forms in water purification filters. However, while it is desirable to increase the amount of activated carbon fiber packed into the filter to maintain high water purification performance, activated carbon fiber sheets have low tensile strength and cannot be tightly wound, so they must be wound loosely. As a result, it is difficult to increase the amount of packed into the activated carbon fiber sheet. Moreover, loosely wound activated carbon fiber sheets tend to trap water over time, making them prone to bursting or other damage due to water pressure. One of the causes of such damage is thought to be the increase in pressure loss that occurs over the course of water purification filters' use.

[0007] In view of the above circumstances, one of the problems to be solved is to develop a molded body for water purification using activated carbon fiber that has continuously high water purification performance and low pressure loss. Another problem to be solved is to provide a molded body that uses activated carbon fiber but is resistant to deformation and exhibits excellent effects for water purification. [Means for solving the problem]

[0008] The invention presented in this disclosure can be understood as several aspects from various perspectives, and includes, for example, the following embodied aspects as means for solving the problems. (Hereinafter, the invention presented in this disclosure will also be referred to as "the present invention.")

[0009] [1] A molded body for water purification, the molded body includes activated carbon and a fibrous binder; The content ratio of the activated carbon and the fibrous binder is 0.3 to 20 parts by weight of the fibrous binder per 100 parts by weight of the activated carbon, The activated carbon contains 5 parts by weight or more of activated carbon fiber per 100 parts by weight of activated carbon, The average fiber length / average fiber diameter of the activated carbon fiber is 5 to 40. Molded body. [2] The molded article according to [1] above, wherein the activated carbon fibers have an average fiber length of 500 μm or more. [3] The molded article according to [1] or [2] above, wherein the activated carbon fibers have an average fiber diameter of 12.0 μm or more. [4] The molded article according to [1] above, wherein the activated carbon fibers have an average fiber length of 500 μm or more and an average fiber diameter of 13.0 μm or more. [5] The molded body according to any one of [1] to [4] above, wherein the activated carbon contains 10 to 90 parts by weight of activated carbon fiber and 90 to 10 parts by weight of granular activated carbon per 100 parts by weight of the activated carbon. [6] The molded article according to any one of the above [1] to [5], wherein the average particle size of the granular activated carbon is 40 to 2000 μm. [7] The molded article according to any one of the above [1] to [6], wherein the fiber material serving as a precursor of the activated carbon fiber has a fineness of 3.3 to 60.0 dtex. [8] The specific surface area of ​​the molded body is 1100 to 2400 m 2 The molded article according to any one of the above [1] to [7], wherein the viscosity is / g. [9] The total pore volume of the molded body is 0.50 to 1.20 cm 3 The molded article according to any one of the above [1] to [8], wherein the viscosity is / g.

[10] The density of the molded body is 0.06 to 0.40 g / cm 3 The molded article according to any one of the above [1] to [9],

[11] The specific surface area of ​​the molded body is 1100 to 2400 m 2 / g, and the total pore volume of the molded body is 0.50 to 1.20 cm 3 / g, and the density of the molded body is 0.06 to 0.40 g / cm 3 The molded article according to any one of the above [1] to [7],

[12] The molded article according to any one of the above [1] to

[10] , wherein the pressure loss of the molded article is 0.0020 MPa or less.

[13] The molded body according to any one of the above [1] to

[12] , which is a molded product of a mixture containing defibrated fibers of the activated carbon fiber and the fibrous binder.

[14] The molded body according to

[13] above, wherein the mixture further contains granular activated carbon. [Effects of the Invention]

[0010] According to some aspects of the invention presented in the present disclosure, a molded article for water purification having excellent water purification performance can be provided. More specifically, according to some aspects of the present invention, it is possible to provide a molded article for water purification that is less likely to deteriorate in chlorine removal performance and less likely to increase in pressure loss even with continuous use. Furthermore, it is possible to obtain a molded article for water purification that has better shape stability than activated carbon fiber alone. By further suppressing pressure loss, it is possible to provide a molded article for water purification that can withstand even a high flow rate. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of an example of the molded article for water purification of the present invention. [Figure 2] FIG. 2 is a longitudinal sectional view of an example of the molded article for water purification of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] In this disclosure, unless otherwise specified, nouns written in Japanese may be either singular or plural, depending on the context of the disclosure. Furthermore, when this disclosure is translated into a language such as English that distinguishes between countable and uncountable nouns, and between singular and plural countable nouns, unless otherwise specified, the singular designation of a noun may include the plural, and the plural designation of a noun may include the singular, depending on the context of the disclosure. Hereinafter, embodiments of the present invention will be described. The embodiments shown below provide specific explanations to facilitate understanding of the present invention, but the present invention is not limited to the embodiments shown below, and each component can be modified as appropriate without departing from the spirit of the present invention. In addition, the embodiments of the present invention will be described below with reference to the drawings. In each figure, the shape, size, and arrangement of the components are shown schematically to facilitate understanding of the present invention, and can be modified as appropriate without departing from the spirit of the present invention. In each figure, similar components are denoted by the same reference numerals, and redundant explanations may be omitted.

[0013] In this disclosure, unless otherwise specified, the expression "AA to BB" in relation to a numerical range means "greater than or equal to AA and less than or equal to BB" (where "AA" and "BB" represent arbitrary numerical values). Furthermore, unless otherwise specified, the units of the lower and upper limits are the same as the units immediately following the latter (i.e., "BB" in this case). Furthermore, in this disclosure, the combination of the lower and upper limits of a numerical range can be arbitrarily selected from the group of lower limit values ​​or the group of upper limit values ​​exemplarily described as preferred numerical values, etc. Furthermore, the expression "X and / or Y" means both X and Y, or either one of them.

[0014] In this disclosure, the term "pore size" refers to the diameter or width of the pore, and not the radius of the pore, unless otherwise specified.

[0015] 1.Molded body for water purification The molded article of the present disclosure can be suitably used for water purification, and more specifically, can be suitably used as a water purification filter.

[0016] One embodiment of the present invention may be a molded body for water purification, including at least activated carbon and a fibrous binder. That is, the molded body may be a molded body obtained by binding activated carbon with a fibrous binder and molding the resulting molded body. By incorporating a fibrous binder and molding the molded body, mechanical strength is improved, and a molded body that is less likely to lose its shape can be obtained.

[0017] Examples of usable activated carbon include activated carbon fiber and granular activated carbon. Using activated carbon fiber as the activated carbon is preferable for reducing pressure loss. The activated carbon may be entirely activated carbon fiber, or a mixture of activated carbon fiber and granular activated carbon may be used. When using a mixture of activated carbon fiber and granular activated carbon, it is preferable that at least 10 parts by weight of activated carbon fiber is contained per 100 parts by weight of activated carbon. Furthermore, using a mixture of activated carbon fiber and granular activated carbon as the activated carbon is preferable from the viewpoint of the reactivity and durability of chlorine removal performance. Generally, activated carbon fiber has a high (fast) reactivity in chlorine removal performance, but tends to have a short durability. On the other hand, granular activated carbon generally has a low (slow) reactivity in chlorine removal performance, but tends to have a long durability. By using these two types of activated carbon in combination, a water purification molded product with an excellent balance of reactivity and durability of chlorine removal performance can be obtained.

[0018] In this disclosure, "chlorine removal performance" refers to the ability to reduce chlorine concentration, and in a more specific aspect, refers to the ability to reduce chlorine concentration in water. Generally, tap water, bath water, pool water, and other waters are disinfected with chlorine. Chlorine compounds present in water as oxidizing chemical species are collectively referred to as "residual chlorine." "Residual chlorine" is classified into "free residual chlorine" and "combined residual chlorine." The term "free residual chlorine" includes hypochlorite and hypochlorite ions. The term "combined residual chlorine" includes monochloramine, dichloramine, and trichloramine. In this disclosure, "chlorine removal performance" specifically refers to the ability to reduce one, two or more, or all of the chlorine components, such as chlorine, chloride ions, and residual chlorine, and in short, refers to the ability to reduce chlorine concentration, as described above.

[0019] The activated carbon fiber is preferably blended in the form of defibrated fibers. By mixing the defibrated fibers with the fibrous binder, the two fibers are adequately entangled and bonded well, which improves the mechanical strength of the molded product and makes it more resistant to deformation.

[0020] The activated carbon preferably contains a predetermined amount or more of activated carbon fiber as a constituent component. The lower limit of the amount of activated carbon fiber in the activated carbon is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, and even more preferably 15, 20, or 25 parts by weight or more per 100 parts by weight of the activated carbon. The content of activated carbon fiber as described above is suitable for producing a molded article that is excellent in chlorine removal performance and has little pressure loss.

[0021] In one embodiment of the present invention, activated carbon may be used 100%. In another embodiment, activated carbon may be used in combination with granular activated carbon. Here, "combined use" refers to, for example, the use of a mixture of activated carbon fiber and granular activated carbon. When activated carbon fiber and granular activated carbon are combined, the ratio of activated carbon fiber to granular activated carbon is preferably 5-95 parts by weight:95-5 parts by weight, more preferably 10-90 parts by weight:90-10 parts by weight, 15-85 parts by weight:85-15 parts by weight, or 20-80 parts by weight:80-20 parts by weight, per 100 parts by weight of activated carbon. When granular activated carbon is used, it is preferable to use at least 5 parts by weight per 100 parts by weight of activated carbon. If the ratio is less than 5 parts by weight, the effect of adding granular activated carbon is less apparent.

[0022] The activated carbon fiber and granular activated carbon will be described in detail later.

[0023] The fibrous binder is not particularly limited as long as it can be fibrillated to entangle activated carbon fibers or granular activated carbon and form a shape. A wide range of synthetic and natural products can be used. Examples of such fibrous binders include acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, cellulose fibers, nylon fibers, and aramid fibers.

[0024] The content ratio of activated carbon fiber and fibrous binder in the water purification molded body may be, for example, 0.3 to 20.0 parts by weight of fibrous binder per 100 parts by weight of activated carbon. The lower limit of the fibrous binder may preferably be 0.5 parts by weight, 0.8 parts by weight, 1.0 parts by weight, 2.0 parts by weight, or 3.0 parts by weight or more. The upper limit of the fibrous binder may preferably be 18 parts by weight, 15 parts by weight, or 10 parts by weight or less. By setting such a content ratio, the molded body can be prepared so as to achieve both mechanical strength and water purification performance. If mechanical strength is desired to be further increased, the amount of fibrous binder may be increased, and if water purification performance is more important, the amount of fibrous binder may be set to a lower level.

[0025] By blending the above-mentioned fibrous binder as the binder in the above-mentioned content ratio, it is possible to avoid the clogging of the pores of the activated carbon fiber, which would otherwise cause a decrease in properties such as water purification performance and pressure loss, and to obtain a water purification molded body that maintains the excellent properties of the activated carbon fiber and has excellent properties such as water purification performance and pressure loss.

[0026] In one embodiment of the present invention, the water purification molded article can be made into a more preferred embodiment by further satisfying one or any two or more of the following specified items regarding the molded article, activated carbon fiber, and granular activated carbon. The combination of the following specified items can be selected arbitrarily according to the desired requirements.

[0027] <Specific surface area of ​​molded body> In one embodiment of the present invention, the specific surface area of ​​the molded article for water purification is preferably 1100 to about 2400 m 2 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the specific surface area of ​​the molded article for water purification is preferably 1100 m 2 / g or more, more preferably 1200m 2 / g or more, more preferably 1300, 1400, 1500, 1600, or 1700 m 2 / g or more. In one embodiment of the present invention, the larger the specific surface area of ​​the molded body for water purification, the better from the viewpoint of water purification performance. In the case of the molded body for water purification, the upper limit of the specific surface area is approximately 2400, 2300, 2200, or 2100 m 2 / g or less. Setting the specific surface area within the above range is suitable for obtaining a water purification molded article having excellent performance in removing chlorine, etc. It is also suitable for suppressing pressure loss while maintaining a wide specific surface area.

[0028] <Total pore volume of molded body> In one embodiment of the present invention, the total pore volume of the molded article for water purification is preferably 0.50 to 1.20 cm3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the total pore volume of the water purification molded article is preferably 0.50 cm 3 / g or more, more preferably 0.60 cm 3 / g or more, more preferably 0.70 or 0.80 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the total pore volume of the activated carbon fiber that can be used in the molded article for water purification is preferably 1.20 cm 3 . 3 / g or less, more preferably 1.10 cm 3 / g or less, more preferably 1.00 cm 3 / g or less. Setting the total pore volume within the above range is suitable for producing a water purification molded article that is excellent in the ability to remove chlorine and the like.

[0029] <Average pore size of molded body (average pore diameter)> In this disclosure, the term "pore size" refers to the diameter or width of the pore, and not the radius of the pore, unless otherwise specified. In one embodiment of the present invention, the average pore size of the molded article for water purification may be preferably 1.69 to 4.00 nm. In one embodiment of the present invention, the lower limit of the average pore size of the molded article for water purification is preferably 1.69 nm or more, more preferably 1.70 nm or more, and even more preferably 1.72, 1.75, 1.78, or 1.80 nm or more. In one embodiment of the present invention, the upper limit of the average pore size of the activated carbon fiber that can be used in the molded article for water purification can be any value, but is preferably 4.00 nm or less, more preferably 3.50 nm or less, and even more preferably 3.00 nm or less. Setting the average pore size within the above range is suitable for producing a water purification molded article that is excellent in the ability to remove chlorine and the like.

[0030] <Ultramicropore volume of compact: V 0.7 > In this disclosure, the term "ultramicropores" refers to pores with a pore diameter of 0.7 nm or less.

[0031] In one embodiment of the present invention, the ultramicropore volume of the molded article for water purification is preferably 0.05 to 0.30 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the ultramicropore volume of the water purification molded article is preferably 0.05 cm 3 / g or more, more preferably 0.08 cm 3 / g or more, more preferably 0.10 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the ultramicropore volume of the activated carbon fiber that can be used in the molded article for water purification is preferably 0.30 cm 3 / g or less, more preferably 0.29, 0.26, or 0.24 cm 3 / g or less, more preferably 0.22 or 0.20 cm 3 / g or less. Setting the ultramicropore volume within the above range is suitable for producing a water purification molded article that is excellent in the ability to remove chlorine and the like.

[0032] <Micropore volume: V 2.0 > In this disclosure, the term "micropore" refers to a pore with a pore diameter of 2.0 nm or less.

[0033] In one embodiment of the present invention, the micropore volume of the molded article for water purification is preferably 0.30 to 1.00 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the micropore volume of the molded article for water purification is preferably 0.30 cm 3 / g or more, more preferably 0.40 or 0.50 cm 3 / g or more, more preferably 0.60 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the micropore volume of the molded article for water purification is preferably 1.00 cm 3 / g or less, more preferably 0.90 cm 3 / g or less, more preferably 0.80 cm 3 / g or less. By setting the micropore volume within the above range, an excellent molded article for water purification can be obtained that has high performance in removing chlorine and the like and low pressure loss.

[0034] <V: Pore volume of pores with diameters greater than 0.7 nm and less than 2.0 nm 0.7-2.0 (About the molded body) Pore ​​volume V of pores with a diameter of more than 0.7 nm and less than 2.0 nm 0.7-2.0 can be calculated by the following formula 1 using the value a of the ultramicropore volume and the value b of the micropore volume. V 0.7-2.0 =ba Equation 1

[0035] In one embodiment of the present invention, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 is preferably 0.20 to 1.20 cm 3 / g. More specifically, it is as follows. In one embodiment of the water purification molded article, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The lower limit is preferably 0.20 cm 3 / g or more, more preferably 0.30 cm 3 / g or more, more preferably 0.36, 0.40, or 0.45 cm 3 / g or more. In one embodiment of the water purification molded article, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The upper limit is preferably 1.20 cm 3 / g or less, more preferably 1.00 cm 3 / g or less, more preferably 0.90, 0.80, 0.70, or 0.60 cm 3 / g or less. The pore volume V0.7-2.0 Setting the value of the surface roughness to the above range is suitable for obtaining a water purifying molded article having excellent performance in removing chlorine and the like.

[0036] <Ratio of the volume of ultramicropores to the volume of micropores: R 0.7 / 2.0 (About the molded body) The ratio R of the volume of ultramicropores with a pore diameter of 0.7 nm or less to the volume of micropores with a pore diameter of 2.0 nm or less 0.7 / 2.0 can be calculated by the following formula 2 using the value a of the ultramicropore volume and the value b of the micropore volume. R 0.7 / 2.0 =a / b×100(%)...Formula 2

[0037] In one embodiment of the present invention, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 is preferably 15.0 to 40.0%. More specifically, it is as follows. In one embodiment of the water purification molded article, the abundance ratio R of the ultramicropore volume to the micropore volume 0.7 / 2.0 The lower limit of the above range is preferably 15.0% or more, more preferably 18.0% or more, and even more preferably 19.0% or more. In one embodiment of the water purification molded article, the abundance ratio R of the ultramicropore volume to the micropore volume 0.7 / 2.0 The upper limit of the ratio may be preferably 40.0% or less, more preferably 30.0, 28.0, or 25.0% or less, and even more preferably 24.0, 23.0, or 22.0% or less. The abundance ratio R of the ultramicropore volume 0.7 / 2.0 Setting the value of the surface roughness to the above range is suitable for obtaining a water purifying molded article having excellent performance in removing chlorine and the like.

[0038] <Density of molded body (humidity-controlled density: temperature 23°C, relative humidity 50%)> In one embodiment of the present invention, the moisture-conditioned density of the molded article for water purification is preferably 0.06 to 0.40 g / cm 3More specifically, it can be as follows. In one embodiment of the present invention, the lower limit of the humidity-conditioned density of the water purification molded article is preferably 0.06 g / cm 3 More preferably, 0.08 g / cm 3 or more, more preferably 0.10, 0.12, 0.14, 0.16, or 0.17 g / cm 3 It could be more than that. In one embodiment of the present invention, the upper limit of the humidity-conditioned density of the water purification molded article is preferably 0.40 g / cm 3 or less, more preferably 0.35 g / cm 3 or less, more preferably 0.32, 0.30, 0.29, 0.28, 0.27, or 0.26 g / cm 3 It can be the following: By setting the density within the above range, a water purification molded body can be obtained that is superior in terms of the water purification performance and pressure loss per volume required for a water purification filter. Furthermore, by setting the density at or above the above lower limit, it is possible to avoid a decrease in mechanical properties (e.g., strength, etc.). The density of the water purification molded body can be adjusted by adjusting the fiber diameter of the carbon fiber, the fiber length by adjusting the stirring force during defibration of the carbon fiber, and the suction force when suction molding the mixed slurry with the fibrous binder.

[0039] <Pressure loss of molded body> In one embodiment of the present invention, the molded article is suitable as a water purification filter. As such a molded article, one having reduced pressure loss is preferred. In one embodiment of the present invention, the pressure loss may preferably be 0.00005 MPa (0.05 kPa) to 0.020 MPa. More specifically, it is as follows. The upper limit of the pressure loss may be preferably 0.02, 0.01, 0.005, 0.004, or 0.003 MPa or less, more preferably 0.0020 MPa or less, and even more preferably 0.0019, 0.0018, 0.0017, 0.0016, 0.0015, or 0.0014 MPa or less. The lower the pressure loss, the better, and from the viewpoint of the original purpose of water purification performance, the lower limit of the pressure loss may preferably be 0.00005 MPa (0.05 kPa), 0.0005 MPa (0.5 kPa), or 0.0008 MPa (0.8 kPa) or more.

[0040] <Chlorine concentration reduction performance> A water purification filter preferably has a long time period during which the residual chlorine concentration can be reduced. Using the residual concentration test shown below as an indicator, the residual chlorine concentration 60 minutes after the start of water flow is preferably 5.00, 4.00, 2.00, or 1.00 ppm or less, more preferably 0.50 ppm or less, and even more preferably 0.10, 0.05, or 0.01 ppm or less.

[0041] An embodiment of the present invention will be described with reference to the drawings. The water purification filter 1 shown in Fig. 1 has end caps 12 attached to both ends of a cylindrical body 11 obtained by molding a slurry containing activated carbon fiber, granular activated carbon, and a fibrous binder. The water purification filter 1 can be used as a unit, as an easily replaceable cartridge. Fig. 2 is a vertical cross-sectional view of the water purification filter shown in Fig. 1. The cylindrical body 11 has a hollow portion whose center line is the axial core line indicated by line X-X'.

[0042] Hereinafter, in one embodiment of the present invention, embodiments of materials such as activated carbon fiber, granular activated carbon, and fibrous binder used in the molded body will be described in more detail.

[0043] 2. Activated carbon fiber In one embodiment of the present invention, activated carbon fiber is used as one type of activated carbon. As the activated carbon, activated carbon fiber may be used alone or a mixture of activated carbon fiber and granular activated carbon may be used.

[0044] In one embodiment of the present invention, the activated carbon fiber that can be used in the molded article for water purification can be made into a more preferred embodiment by further satisfying at least one or any two or more of the following specified conditions.

[0045] <Average fiber diameter of activated carbon fibers> In one embodiment of the present invention, the average fiber diameter of the activated carbon fibers contained in the molded article for water purification may be preferably 8.0 to 60.0 μm. More specifically, the average fiber diameter is as follows. In one embodiment of the present invention, the lower limit of the average fiber diameter of the activated carbon fiber contained in the water purification molded article may be preferably 8.0, 9.0, 10.0, 11.0, 12.0, or 13.0 μm or more, more preferably 14.0 μm or more, and even more preferably 15.0, 16.0, 17.0, 18.0, 19.0, or 20.0 μm or more. In one embodiment of the present invention, the upper limit of the average fiber diameter of the activated carbon fibers contained in the water purification molded article can be any value from the viewpoint of suppressing pressure loss, but taking into consideration the balance with water purification performance, the upper limit can be, for example, 60.0 μm or less, preferably 55.0 μm or less, and more preferably 50.0, 45.0, 40.0, or 35.0 μm. The average fiber diameter of the fibers constituting the activated carbon fiber in the above range is suitable for obtaining an activated carbon fiber with a lower pressure loss. In addition, although increasing the pore volume results in an increase in the number of voids in the fiber body, increasing the average fiber diameter to a certain extent is also suitable in terms of maintaining the strength of the fiber, and therefore the desired pore volume can be adjusted, which can also contribute to improving the ability to remove chlorine and the like.

[0046] <Average fiber length of activated carbon fiber> In one embodiment of the present invention, the average fiber length of the activated carbon fibers contained in the molded article for water purification may be preferably 500 to 5000 μm. In one embodiment of the present invention, the lower limit of the average fiber length of the activated carbon fibers contained in the water purification molded article is preferably 500, 600, 700 μm, or 800 μm or more, more preferably 850 or 900 μm or more, and even more preferably 950 or 1000 μm or more. In one embodiment of the present invention, the upper limit of the average fiber length of the activated carbon fibers contained in the molded article for water purification is preferably 5000 μm or less, more preferably 4000, 3000, 2500, 2000, 1500, or 1200 μm or less, and even more preferably 1100 μm or less. The average fiber length of the fibers constituting the activated carbon fiber in the above range is suitable for obtaining an activated carbon fiber with a lower pressure loss, and also for obtaining a molded product with a good bond to the fibrous binder, which can improve the mechanical strength of the molded product and make it more resistant to deformation.

[0047] <Coefficient of variation of activated carbon fiber length (standard deviation of fiber length / average fiber length)> In one embodiment of the present invention, the coefficient of variation of the fiber length of the activated carbon fiber contained in the molded article for water purification may preferably be 0.10 to 2.50. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the coefficient of variation of the fiber length of the activated carbon fiber contained in the water purification molded article is preferably 0.10 or more, more preferably 0.20, 0.30, or 0.40 or more, and even more preferably 0.50 or 0.60 or more. In one embodiment of the present invention, the upper limit of the coefficient of variation of the fiber length of the activated carbon fiber contained in the water purification molded article is preferably 2.50 or less, more preferably 2.00, 1.50, or 1.00, and even more preferably 0.90, 0.80, or 0.70 or less. The coefficient of variation of the fiber length of the fibers constituting the activated carbon fiber is preferably within the above range in order to obtain an activated carbon fiber with a lower pressure loss.

[0048] <Average fiber length / average fiber diameter of activated carbon fiber> In one embodiment of the present invention, the average fiber length / average fiber diameter of the activated carbon fibers contained in the molded article for water purification may preferably be 5 to 100. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the average fiber length / average fiber diameter of the activated carbon fibers contained in the molded article for water purification is preferably 5 or more, more preferably 10 or 15 or more, and even more preferably 20 or more. In one embodiment of the present invention, the upper limit of the average fiber length / average fiber diameter of the activated carbon fibers contained in the water purification molded article is preferably 100 or less, more preferably 90, 80, 70, 65, or 60, and even more preferably 55, 50, 45, or 40 or less. The average fiber length / average fiber diameter of the fibers constituting the activated carbon fiber is preferably within the above range in order to obtain an activated carbon fiber with a lower pressure loss.

[0049] <Fineness of activated carbon fiber precursor> In order to obtain activated carbon fibers having the above-described fiber diameters, the fiber diameter (as fineness) of the precursor fiber of the activated carbon fiber is preferably within the following ranges. That is, it can be said that using the following fibers as precursors is suitable for obtaining activated carbon fibers with lower pressure loss. In one embodiment of the present invention, the fiber diameter (fineness) of the precursor fiber may preferably be 3.3 to 60.0 dtex. More specifically, it is as follows. The lower limit of the fiber diameter (fineness) of the precursor fiber is preferably 3.3 dtex or more, more preferably 4.0 dtex or more, and even more preferably 5.0, 6.0, 8.0, 10.0, 12.0, or 15.0 dtex or more. The upper limit of the fiber diameter (fineness) of the precursor fiber is preferably 60.0 dtex or less, more preferably 50.0 dtex or less, 45.0, even more preferably 40.0, or 35.0, 30.0, or 25.0 dtex or less.

[0050] <Specific surface area of ​​activated carbon fiber> In one embodiment of the present invention, the specific surface area of ​​the activated carbon fiber contained in the molded article for water purification is preferably 1100 to about 2400 m 2 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the specific surface area of ​​the activated carbon fiber contained in the molded article for water purification is preferably 1100 m 2 / g or more, more preferably 1200, 1300, 1400, 1500, or 1600 m 2 / g or more, more preferably 1700 or 1800m 2 / g or more. In one embodiment of the present invention, the specific surface area of ​​the activated carbon fiber contained in the molded article for water purification is generally preferably larger from the viewpoint of water purification performance. In the case of the molded article for water purification, the upper limit of the specific surface area is generally 2400, 2300, 2200, or 2100 m. 2 / g or less. The specific surface area in the above range is suitable for obtaining a water purification molded article having excellent chlorine removal performance, and is also suitable for suppressing pressure loss while maintaining a wide specific surface area.

[0051] <Total pore volume of activated carbon fiber> In one embodiment of the present invention, the total pore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.50 to 1.20 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the total pore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.50 cm 3 / g or more, more preferably 0.60 or 0.70 cm 3 / g or more, more preferably 0.80 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the total pore volume of the activated carbon fiber contained in the water purification molded article is preferably 1.20 cm 3 / g or less, more preferably 1.10 cm 3 / g or less, more preferably 1.00 cm 3 / g or less. Setting the total pore volume within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0052] <Average pore size of activated carbon fiber> In one embodiment of the present invention, the average pore size of the activated carbon fiber contained in the molded article for water purification may be preferably 1.69 to 4.00 nm. In one embodiment of the present invention, the lower limit of the average pore size of the activated carbon fiber contained in the molded article for water purification is preferably 1.69 nm or more, more preferably 1.70 nm or more, and even more preferably 1.72 or 1.75 nm or more. In one embodiment of the present invention, the upper limit of the average pore size of the activated carbon fiber contained in the molded article for water purification can be any value, but is preferably 4.00 nm or less, more preferably 3.50 nm or less, and even more preferably 3.00 nm or less. Setting the average pore size within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0053] <Ultramicropore volume of activated carbon fiber: V 0.7 > In one embodiment of the present invention, the ultramicropore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.05 to 0.30 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the ultramicropore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.05 cm 3 / g or more, more preferably 0.08 cm 3 / g or more, more preferably 0.10 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the ultramicropore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.30 cm 3 / g or less, more preferably 0.25 cm 3 / g or less, more preferably 0.23, 0.20, 0.18, or 0.15 cm3 / g or less. Setting the ultramicropore volume within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0054] <Micropore volume of activated carbon fiber: V 2.0 > In one embodiment of the present invention, the activated carbon fiber contained in the molded article for water purification preferably has a micropore volume of 0.40 to 1.00 cm. 3 / g or less. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the micropore volume of the activated carbon fiber contained in the molded article for water purification is preferably 0.40 cm 3 / g or more, more preferably 0.50 cm 3 / g or more, more preferably 0.55 or 0.60 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the micropore volume of the activated carbon fiber contained in the molded article for water purification is preferably 1.00 cm 3 . 3 / g or less, more preferably 0.90 cm 3 / g or less, more preferably 0.80 cm 3 / g or less. Setting the micropore volume within the above range is suitable for producing a water purifying molded article having excellent chlorine removal performance.

[0055] <V: Pore volume of pores with diameters greater than 0.7 nm and less than 2.0 nm 0.7-2.0 (About activated carbon fiber) In one embodiment of the activated carbon fiber contained in the water purification molded article, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 is preferably 0.20 to 1.20 cm 3 / g. More specifically, it is as follows. In one embodiment of the activated carbon fiber contained in the water purification molded article, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The lower limit is preferably 0.20 cm3 / g or more, more preferably 0.30, 0.36, or 0.40 cm 3 / g or more, more preferably 0.43, 0.45, or 0.50 cm 3 / g or more. In one embodiment of the activated carbon fiber contained in the water purification molded article, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The upper limit is preferably 1.20 cm 3 / g or less, more preferably 1.00 cm 3 / g or less, more preferably 0.90, 0.80, 0.75, 0.70, 0.65, or 0.60 cm 3 / g or less. The pore volume V 0.7-2.0 Setting the content of the polymer in the above range is suitable for obtaining a molded article for water purification having excellent chlorine removal performance.

[0056] <Ratio of the volume of ultramicropores to the volume of micropores: R 0.7 / 2.0 (About activated carbon fiber)

[0057] In one embodiment of the activated carbon fiber contained in the molded article for water purification, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 is preferably 15.0 to 60.0%. More specifically, it is as follows. In one embodiment of the activated carbon fiber contained in the molded article for water purification, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 The lower limit of the above range is preferably 15.0% or more, more preferably 18.0% or more, and even more preferably 19.0% or more. In one embodiment of the activated carbon fiber contained in the molded article for water purification, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 The upper limit of the ratio may be preferably 60.0% or less, more preferably 50.0% or less, and even more preferably 40.0, 30.0, or 25.0% or less. The abundance ratio R of the ultramicropore volume 0.7 / 2.0Setting the value of the surface roughness to the above range is suitable for obtaining a water purifying molded article having excellent performance in removing chlorine and the like.

[0058] <Humidity-controlled density of activated carbon fiber (at a temperature of 23°C and a relative humidity of 50%)> In one embodiment of the present invention, the activated carbon fiber contained in the molded article for water purification may preferably have a predetermined density. The density may be measured using the humidity-conditioned density. In the present disclosure, the humidity-conditioned density is the density measured under conditions of 23°C and 50% relative humidity. In one embodiment of the present invention, the humidity-controlled density (density under conditions of 23°C and 50% relative humidity) of the activated carbon fiber contained in the molded article for water purification is preferably 0.010 to 0.400 g / cm. 3 More specifically, it can be as follows. In one embodiment of the present invention, the lower limit of the humidity-controlled density (density under conditions of 23°C and 50% relative humidity) of the activated carbon fiber contained in the molded article for water purification is preferably 0.010 g / cm 3 or more, more preferably 0.015, 0.020, or 0.030 g / cm 3 More preferably, 0.040 or 0.050 g / cm 3 It could be more than that. In one embodiment of the present invention, the upper limit of the humidity-controlled density of the activated carbon fiber contained in the molded article for water purification is preferably 0.400 g / cm. 3 or less, more preferably 0.300 g / cm 3 or less, more preferably 0.200, 0.150, 0.140, 0.130, 0.120, 0.110, or 0.100 g / cm 3 It can be the following:

[0059] By setting the density within the above range, a molded body can be obtained that has better water purification performance per volume required for a water purification filter. Furthermore, by setting the density at or above the lower limit, it is possible to avoid a decrease in mechanical properties (e.g., strength, etc.). Furthermore, the dry density of the molded body can be adjusted by adjusting the fiber diameter of the carbon fibers, the fiber length by adjusting the stirring force during defibration of the carbon fibers, and the suction force when suction molding the mixed slurry with the fibrous binder, thereby suppressing pressure loss of the molded body.

[0060] <Moisture content of activated carbon fiber> In one embodiment of the present invention, the activated carbon fiber contained in the molded article for water purification preferably has a predetermined moisture content. In one embodiment of the present invention, the moisture content of the activated carbon fiber contained in the molded article for water purification (under conditions of 23°C and relative humidity of 50%) may be preferably 1.0 to 30.0%. More specifically, it is as follows. For example, the lower limit of the moisture content under conditions of 23°C and a relative humidity of 50% can be preferably 1.0% or more, more preferably 2.0% or more, and even more preferably 3.0% or more. The upper limit of the moisture content under conditions of 23°C and relative humidity of 50% can be preferably 30.0 or 25.0% or less, more preferably 20.0 or 15.0% or less, and even more preferably 10.0 or 8.0% or less. Setting the water content within the above range under the above conditions is suitable for producing a water purifying molded article having excellent water purification performance.

[0061] 3. Granular activated carbon In the present disclosure, granular activated carbon refers to activated carbon that has a granular shape and an average particle size of 40 to 2000 μm.

[0062] <Granular activated carbon particle size> In one embodiment of the present invention, the average particle size of the granular activated carbon contained in the molded article for water purification may be preferably 40 to 2000 μm. In one embodiment of the present invention, the lower limit of the average particle size of the granular activated carbon contained in the water purification molded article is preferably 40 μm or more, more preferably 80 μm or more, and even more preferably 120, 160, or 200 μm or more. In one embodiment of the present invention, the upper limit of the average particle size of the granular activated carbon contained in the water purification molded article is preferably 2000 μm or less, more preferably 1500 μm or less, and even more preferably 1000, 800, 700, or 600 μm or less. Setting the particle size of the granular activated carbon within the above range is preferable from the viewpoints of reducing pressure loss and reducing outflow during the initial filtration, etc. Furthermore, by setting the particle size larger than the above lower limit, it is possible to prevent the loss of particles that are too small during initial use.

[0063] <Specific surface area of ​​granular activated carbon> In one embodiment of the present invention, the specific surface area of ​​the granular activated carbon contained in the molded article for water purification is preferably 1100 to about 2400 m 2 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the specific surface area of ​​the granular activated carbon contained in the molded article for water purification is preferably 1100 m 2 / g or more, more preferably 1200, 1300, 1400, 1500, or 1600 m 2 / g or more, more preferably 1700 or 1800m 2 / g or more. In one embodiment of the present invention, the specific surface area of ​​the granular activated carbon contained in the molded body for water purification is generally preferably larger from the viewpoint of water purification performance. In the case of the molded body for water purification, the upper limit of the specific surface area is generally 2400, 2300, 2200, or 2100 m. 2 / g or less. The specific surface area in the above range is suitable for obtaining a water purification molded article having excellent chlorine removal performance, and is also suitable for suppressing pressure loss while maintaining a wide specific surface area.

[0064] <Total pore volume of granular activated carbon> In one embodiment of the present invention, the total pore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.50 to 1.20 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the total pore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.50 cm 3 / g or more, more preferably 0.60 or 0.70 cm 3 / g or more, more preferably 0.80 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the total pore volume of the granular activated carbon contained in the water purification molded article is preferably 1.20 cm 3 / g or less, more preferably 1.10 cm 3 / g or less, more preferably 1.00 cm 3 / g or less. Setting the total pore volume within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0065] <Average pore diameter of granular activated carbon> In one embodiment of the present invention, the average pore size of the granular activated carbon contained in the molded article for water purification may be preferably 1.69 to 4.00 nm. In one embodiment of the present invention, the lower limit of the average pore size of the granular activated carbon contained in the molded article for water purification is preferably 1.69 nm or more, more preferably 1.70 nm or more, and even more preferably 1.72 or 1.75 nm or more. In one embodiment of the present invention, the upper limit of the average pore size of the granular activated carbon contained in the molded article for water purification can be any value, but is preferably 4.00 nm or less, more preferably 3.50 nm or less, and even more preferably 3.00 nm or less. Setting the average pore size within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0066] Ultramicropore volume of granular activated carbon: V 0.7 > In one embodiment of the present invention, the ultramicropore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.05 to 0.30 cm 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the ultramicropore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.05 cm 3 / g or more, more preferably 0.08 cm 3 / g or more, more preferably 0.10 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the ultramicropore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.30 cm 3 / g or less, more preferably 0.25 cm 3 / g or less, more preferably 0.23, 0.20, 0.18, or 0.15 cm 3 / g or less. Setting the ultramicropore volume within the above range is suitable for producing a water purification molded article having excellent chlorine removal performance.

[0067] <Micropore volume of granular activated carbon: V 2.0 > In one embodiment of the present invention, the micropore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.40 to 1.00 cm. 3 / g. More specifically, it is as follows. In one embodiment of the present invention, the lower limit of the micropore volume of the granular activated carbon contained in the molded article for water purification is preferably 0.40 cm 3 / g or more, more preferably 0.50 cm 3 / g or more, more preferably 0.55 or 0.60 cm 3 / g or more. In one embodiment of the present invention, the upper limit of the micropore volume of the granular activated carbon contained in the molded article for water purification is preferably 1.00 cm. 3 / g or less, more preferably 0.90 cm 3 / g or less, more preferably 0.80 cm 3 / g or less. Setting the micropore volume within the above range is suitable for producing a water purifying molded article having excellent chlorine removal performance.

[0068] <V: Pore volume of pores with diameters greater than 0.7 nm and less than 2.0 nm 0.7-2.0 (About granular activated carbon) In one embodiment of the present invention, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 is preferably 0.20 to 1.20 cm 3 / g. More specifically, it is as follows. In one embodiment of the granular activated carbon contained in the molded body for water purification, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The lower limit is preferably 0.20 cm 3 / g or more, more preferably 0.30, 0.36, or 0.40 cm 3 / g or more, more preferably 0.43, 0.45, or 0.50 cm 3 / g or more. In one embodiment of the granular activated carbon contained in the molded body for water purification, the pore volume V of pores having a pore diameter of more than 0.7 nm and not more than 2.0 nm is 0.7-2.0 The upper limit is preferably 1.20 cm 3 / g or less, more preferably 1.00 cm 3 / g or less, more preferably 0.90, 0.80, 0.75, 0.70, 0.65, or 0.60 cm 3 / g or less. The pore volume V 0.7-2.0 Setting the content of the polymer in the above range is suitable for obtaining a molded article for water purification having excellent chlorine removal performance.

[0069] <Ratio of the volume of ultramicropores to the volume of micropores: R 0.7 / 2.0 (About granular activated carbon)

[0070] In one embodiment of the present invention, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0is preferably 15.0 to 60.0%. More specifically, it is as follows. In one embodiment of the granular activated carbon contained in the molded body for water purification, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 The lower limit of the above range is preferably 15.0% or more, more preferably 18.0% or more, and even more preferably 19.0% or more. In one embodiment of the granular activated carbon contained in the molded body for water purification, the abundance ratio R of the ultramicropore volume to the micropore volume is 0.7 / 2.0 The upper limit of the ratio may be preferably 60.0% or less, more preferably 50.0% or less, and even more preferably 40.0, 30.0, or 25.0% or less. The abundance ratio R of the ultramicropore volume 0.7 / 2.0 Setting the value of the surface roughness to the above range is suitable for obtaining a water purifying molded article having excellent performance in removing chlorine and the like.

[0071] <Humidity-controlled density of granular activated carbon (at a temperature of 23°C and a relative humidity of 50%)> In one embodiment of the present invention, the granular activated carbon contained in the molded article for water purification may preferably have a predetermined density. The humidity-conditioned density may be used as an index of density. In the present disclosure, the humidity-conditioned density is the density measured under conditions of 23°C and 50% relative humidity. In one embodiment of the present invention, the humidity-controlled density (density under conditions of 23°C and 50% relative humidity) of the granular activated carbon contained in the molded article for water purification is preferably 0.10 to 0.80 g / cm. 3 More specifically, it can be as follows. In one embodiment of the present invention, the lower limit of the humidity-controlled density (density under conditions of 23°C and 50% relative humidity) of the granular activated carbon contained in the molded article for water purification is preferably 0.10 g / cm 3 or more, more preferably 0.15, 0.2, 0.25, or 0.30 or more.

[0072] In one embodiment of the present invention, the upper limit of the humidity-conditioning density of the granular activated carbon contained in the molded article for water purification is preferably 0.80 g / cm. 3It may be less than or equal to 0.70, 0.60, 0.55, 0.50, or 0.45, more preferably. Setting the humidity-controlled density within the above range is suitable for producing a water purification molded article with excellent water purification performance.

[0073] <Moisture content of granular activated carbon> In one embodiment of the present invention, the granular activated carbon contained in the molded article for water purification preferably has a predetermined moisture content. In one embodiment of the present invention, the moisture content under conditions of 23°C and a relative humidity of 50% can be preferably 1.0 to 30.0%. More specifically, it is as follows. For example, the lower limit of the moisture content under conditions of 23°C and a relative humidity of 50% can be preferably 1.0% or more, more preferably 2.0% or more, and even more preferably 3.0% or more. The upper limit of the moisture content under conditions of 23°C and relative humidity of 50% can be preferably 30.0 or 25.0% or less, more preferably 20.0 or 15.0% or less, and even more preferably 10.0 or 8.0% or less. Setting the water content within the above range under the above conditions is suitable for producing a water purifying molded article having excellent water purification performance.

[0074] In one embodiment of the present invention, the molded body may contain other components in addition to the activated carbon and the fibrous binder. However, it is preferable that the addition of other components be limited to an extent that does not impair the effect of suppressing pressure loss or does not lose its substantial significance.

[0075] 5. Manufacturing method of molded body In one embodiment of the present invention, the molded body can be produced using activated carbon fiber material, or activated carbon fiber and granular activated carbon, and a fibrous binder.

[0076] Activated carbon fiber materials can be produced by carbonizing and activating fibers having a predetermined fiber diameter. The fibers before carbonization and activation are referred to as precursor fibers, and a sheet formed from the precursor fibers is referred to as a precursor fiber sheet. In this disclosure, the term "fiber diameter" refers to the diameter or width of the fibers, not the radius of the fibers, unless otherwise specified. Furthermore, the term "fiber diameter" is primarily used to refer to activated carbon fibers after carbonization and activation.

[0077] 5.1. Production of activated carbon fiber sheets As a method for producing an activated carbon fiber material, an embodiment for producing an activated carbon fiber sheet will be exemplified below. As a preferred embodiment of the method for producing an activated carbon fiber sheet, for example, the following method can be mentioned.

[0078] The method includes carbonizing and activating a precursor fiber sheet carrying either one or both of a phosphoric acid catalyst and an organic sulfonic acid catalyst, The precursor fiber sheet contains cellulosic fibers, and the fiber diameter of the fibers is 3.3 to 60.0 dtex. method.

[0079] In one embodiment of the present invention, a method for producing an activated carbon fiber sheet that can be used can be carried out, for example, by referring to the information below.

[0080] 5.1.1. Preparation of raw material sheet (precursor fiber sheet) <Type of fiber> Examples of fibers constituting the raw material sheet include cellulose-based fibers, pitch-based fibers, PAN-based fibers, and phenolic resin-based fibers, with cellulose-based fibers being preferred.

[0081] <Cellulosic fiber> Cellulose-based fibers are fibers primarily composed of cellulose and / or its derivatives. The cellulose and cellulose derivatives may be of any origin, such as chemically synthesized products, plant-derived, regenerated cellulose, or bacterially produced cellulose. Preferred examples of cellulose-based fibers include fibers made from plant cellulose materials obtained from trees, and fibers made from long fibrous regenerated cellulose materials obtained by chemically treating and dissolving plant cellulose materials (cotton, pulp, etc.). These fibers may also contain components such as lignin and hemicellulose.

[0082] Examples of raw materials for cellulosic fibers (plant cellulose materials, regenerated cellulose materials) include plant cellulose fibers such as cotton (short staple cotton, medium staple cotton, long staple cotton, extra-long staple cotton, etc.), hemp, bamboo, paper mulberry, mitsumata, banana, and tunicates; regenerated cellulose fibers such as cuprammonium rayon, viscose rayon, polynosic rayon, and bamboo-derived cellulose; purified cellulose fibers spun in organic solvents (N-methylmorpholine N-oxide); and acetate fibers such as diacetate and triacetate. Among these, at least one selected from cuprammonium rayon, viscose rayon, and purified cellulose fibers is preferred due to their availability.

[0083] The form of the cellulose-based fiber is not particularly limited, and can be prepared into raw yarn (unprocessed yarn), false twisted yarn, dyed yarn, single yarn, doubled-twisted yarn, covered yarn, etc. depending on the purpose. Furthermore, when the cellulose-based fiber contains two or more raw materials, it may be a blended yarn, a blended twisted yarn, etc. Furthermore, the above-mentioned various raw materials may be used alone or in combination of two or more. Among these, non-twisted yarn is preferred in order to achieve both moldability and mechanical strength of the composite material.

[0084] <Fiber sheet> A fiber sheet is a thin, wide sheet made of many fibers, and includes woven fabrics, knitted fabrics, nonwoven fabrics, and the like.

[0085] There is no particular limitation on the method for weaving cellulosic fibers, and any common method can be used. There is also no particular limitation on the weave of the fabric, and any of the three basic weaves, plain weave, twill weave, and satin weave, can be used.

[0086] In a woven fabric formed from cellulosic fibers, the gap between the warp and weft yarns of the cellulosic fibers is preferably 0.1 to 0.8 mm, more preferably 0.2 to 0.6 mm, and even more preferably 0.25 to 0.5 mm. Furthermore, the basis weight of the woven fabric made of cellulosic fibers is preferably 50 to 500 g / m 2 , more preferably 100 to 400 g / m 2 It is possible.

[0087] By setting the cellulosic fibers and the woven fabric made of cellulosic fibers within the above range, the carbon fiber fabric obtained by heat treating the woven fabric can have excellent strength.

[0088] The method for producing the nonwoven fabric is not particularly limited, and examples include a method in which a fiber sheet is obtained using the above-mentioned fibers cut to an appropriate length as a raw material by a dry method or a wet method, or a method in which a fiber sheet is obtained directly from a solution by an electrospinning method, etc. Furthermore, after the nonwoven fabric is obtained, treatment such as resin bonding, thermal bonding, spunlace, needle punching, etc. may be added in order to bond the fibers together.

[0089] Catalyst In the first manufacturing method, a catalyst is supported on the raw material sheet prepared as described above. The catalyst is supported on the raw material sheet, and the sheet is subjected to a carbonization treatment. The sheet is then activated using water vapor, carbon dioxide, air, or the like, to obtain a porous activated carbon fiber sheet. Examples of the catalyst that can be used include phosphoric acid catalysts and organic sulfonic acid catalysts.

[0090] <Phosphoric acid catalyst> Examples of phosphoric acid catalysts include phosphorus oxyacids such as phosphoric acid, metaphosphoric acid, pyrophosphoric acid, phosphorous acid, phosphonic acid, phosphonous acid, and phosphinic acid; ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate; dimethylphosphonopropanamide; ammonium polyphosphate; polyphosphonitrile chloride; and condensates of phosphoric acid, tetrakis(hydroxymethyl)phosphonium salts, or tris(1-aziridinyl)phosphine oxide with urea, thiourea, melamine, guanine, cyanamide, hydrazine, dicyandiamide, or methylol derivatives thereof, with diammonium hydrogen phosphate being preferred. Phosphoric acid catalysts may be used alone or in combination. When the phosphoric acid catalyst is used as an aqueous solution, its concentration is preferably 0.05 to 2.0 mol / L, more preferably 0.1 to 1.0 mol / L.

[0091] <Organic sulfonic acid catalyst> As the organic sulfonic acid, an organic compound having one or more sulfo groups can be used, and for example, compounds having sulfo groups bonded to various carbon skeletons such as aliphatic and aromatic compounds can be used. From the viewpoint of handling, organic sulfonic acid catalysts with low molecular weights are preferred.

[0092] Examples of organic sulfonic acid catalysts include compounds represented by the formula R-SOH (wherein R represents a linear or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and the alkyl group, cycloalkyl group, and aryl group may each be substituted with an alkyl group, a hydroxyl group, or a halogen group). Examples of organic sulfonic acid catalysts include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, 1-hexanesulfonic acid, vinylsulfonic acid, cyclohexanesulfonic acid, p-toluenesulfonic acid, p-phenolsulfonic acid, naphthalenesulfonic acid, benzenesulfonic acid, and camphorsulfonic acid. Of these, methanesulfonic acid is preferred. One type of organic sulfonic acid catalyst may be used alone, or two or more types may be used in combination.

[0093] When the organic sulfonic acid is used as an aqueous solution, the concentration thereof may be preferably 0.05 to 2.0 mol / L, more preferably 0.1 to 1.0 mol / L.

[0094] <Mixed catalyst> The phosphoric acid catalyst and the organic sulfonic acid catalyst may be mixed and used as a mixed catalyst. The mixing ratio may be adjusted appropriately.

[0095] <Catalyst retention> The catalyst is retained on the raw material sheet. Here, "retained" means that the catalyst is kept in contact with the raw material sheet, and can take various forms such as adhesion, adsorption, or impregnation. There are no particular limitations on the method for retaining the catalyst, but examples include a method of immersing the raw material sheet in an aqueous solution containing the catalyst, a method of sprinkling the aqueous solution containing the catalyst onto the raw material sheet, a method of contacting the raw material sheet with vaporized catalyst vapor, and a method of mixing the fibers of the raw material sheet with an aqueous solution containing the catalyst and then making paper.

[0096] From the viewpoint of sufficient carbonization, a preferred method is to immerse the raw material sheet in an aqueous solution containing the catalyst and impregnate the catalyst deep into the fibers. The temperature during immersion in the aqueous solution containing the catalyst is not particularly limited, but room temperature is preferred. The immersion time is preferably 10 seconds to 120 minutes, more preferably 20 seconds to 30 minutes. By immersion, the fibers constituting the raw material sheet are adsorbed with, for example, 1 to 150 mass %, preferably 5 to 60 mass % of the catalyst. After immersion, the raw material sheet is preferably removed and dried. The drying method may be, for example, leaving it at room temperature or introducing it into a dryer. Drying may be carried out after removal from the aqueous solution containing the catalyst until excess water evaporates and the sample weight remains constant. For example, in the case of room temperature drying, the drying time may be 0.5 days or more. After drying to almost completely eliminate the change in mass, the raw material sheet retaining the catalyst proceeds to the carbonization process.

[0097] 5.1.3. Carbonization After preparing the raw material sheet supporting the catalyst, the sheet is carbonized. The carbonization treatment to obtain the activated carbon fiber sheet can be carried out according to a general method for carbonizing activated carbon, but in a preferred embodiment, the treatment can be carried out as follows.

[0098] The carbonization treatment is usually carried out in an inert gas atmosphere. In the present invention, the inert gas atmosphere means an oxygen-free or low-oxygen atmosphere in which carbon is less likely to undergo a combustion reaction and is carbonized, and is preferably, for example, an argon, nitrogen, or other gas atmosphere.

[0099] The raw material sheet carrying the catalyst is subjected to a heat treatment in the above-mentioned predetermined gas atmosphere to be carbonized.

[0100] In one embodiment of the present invention, the heating temperature in the carbonization treatment may preferably be 300 to 1400° C. More specifically, it is as follows. The lower limit of the heating temperature is preferably 300°C or higher, more preferably 350°C or higher, and even more preferably 400°C or higher or 750°C or higher. The upper limit of the heating temperature is preferably 1400°C or lower, more preferably 1300°C or lower, and even more preferably 1200°C or lower or 1000°C or lower. By setting the heating temperature in this manner, a carbon fiber sheet in which the fiber morphology is maintained can be obtained. If the heating temperature is below the above lower limit, the carbon content of the carbon fiber will be 80% or less, and carbonization will likely be insufficient.

[0101] In one embodiment of the present invention, the heat treatment time in the carbonization treatment, including the time required for temperature rise, is preferably 10 to 180 minutes. More specifically, it is as follows. The lower limit of the heat treatment time, including the time for temperature rise, is preferably 10 minutes or more, more preferably 11 minutes or more, even more preferably 12, 15, 20, 25 minutes or more, and more preferably 30 minutes or more. The upper limit of the heat treatment time can be set arbitrarily, but is preferably 180 minutes or less, more preferably 160 minutes or less, and even more preferably 140 minutes or less. By thoroughly impregnating the raw material sheet with the catalyst, setting the heating temperature to the above-mentioned preferred temperature, and adjusting the heat treatment time, it is possible to adjust the degree of pore formation and to adjust the physical properties of the porous body, such as the specific surface area, the volume of various pores, and the average pore diameter. If the heat treatment time is shorter than the above lower limit, carbonization tends to be insufficient.

[0102] Furthermore, the heat treatment may be a reheat treatment in a predetermined gas atmosphere after the above-described heat treatment (sometimes referred to as a primary heat treatment). That is, the carbonization treatment may be carried out in multiple stages of heat treatments with different conditions, such as temperature. By carrying out the primary heat treatment and the reheat treatment under predetermined conditions, it may be possible to adjust the physical properties, promote carbonization and subsequent activation more smoothly, and obtain an activated carbon fiber sheet with excellent water purification performance.

[0103] 5.1.4. Activation treatment In one embodiment of the present invention, the activation treatment can be carried out, for example, by continuously supplying water vapor, carbon dioxide, or an alkaline chemical after the heat treatment and maintaining the material at an appropriate activation temperature for a predetermined period of time, thereby obtaining an activated carbon fiber sheet.

[0104] In one embodiment of the present invention, the heating temperature in the activation treatment can be preferably 300 to 1400° C. More specifically, it is as follows. The lower limit of the activation temperature is preferably 300°C or higher, more preferably 350°C or higher, and even more preferably 400, 500, 600, 700, or 750°C or higher. On the other hand, the upper limit of the activation temperature can be preferably 1400°C or lower, more preferably 1300°C or lower, and even more preferably 1200 or 1000°C or lower. When the activation treatment is carried out immediately after the heat treatment, it is desirable to adjust the temperature to approximately the same as the heat treatment temperature.

[0105] In one embodiment of the present invention, the activation time in the activation treatment can be preferably 1 to 180 minutes. More specifically, it is as follows. The lower limit of the activation time is preferably 1 minute or more, more preferably 5 minutes or more. The upper limit of the activation time can be any value, but is preferably 180 minutes or less, more preferably 160 minutes or less, and even more preferably 140 minutes or less, 100 minutes or less, 50 minutes or less, or 30 minutes or less.

[0106] 5.2. Fibrous binder The fibrous binder is not particularly limited as long as it can fibrillate a fiber material to entangle activated carbon such as activated carbon fiber and granular activated carbon and form it. A wide range of synthetic and natural products can be used.

[0107] 5.3. Granular activated carbon The above-mentioned granular activated carbon is commercially available. It is preferable to prepare granular activated carbon that satisfies the above-mentioned requirements such as the preferred particle size.

[0108] 5.4. Preparation of compacts The method for processing the molded body is not particularly limited, but for example, a mixture of activated carbon fiber and a fibrous binder, or a mixture further containing granular activated carbon, can be prepared and molded to obtain a molded body. In one embodiment, for example, a molded body can be produced as follows.

[0109] <Preparation of slurry containing raw materials> The activated carbon fiber sheet and fibrous binder prepared in advance are mixed with water, and then defibrated and dispersed in a mixer to mix the two, thereby obtaining a first slurry containing both. The activated carbon fiber sheet to be added to the mixer may be cut into small pieces of an appropriate size depending on the size of the mixer, etc.

[0110] When granular activated carbon is further added, the granular activated carbon is further added to the first slurry and stirred with a mixer to obtain a second slurry.

[0111] <Formation of molded body> The first slurry or the second slurry obtained as described above can be poured into a mold of a desired shape, pressed to remove water, and then dried to obtain a molded body. [Example]

[0112] The present invention will be described in more detail below with reference to examples, but the technical scope of the present invention in this disclosure is not limited to the following examples.

[0113] Example 1 (1.1) Preparation of activated carbon fiber sheet Rayon fiber (17 dtex, fiber length 76 mm) basis weight 400 g / m 2The needle-punched nonwoven fabric was impregnated with a 6-10% aqueous solution of diammonium hydrogen phosphate, squeezed, and then dried to deposit 8-10% by weight. The resulting pretreated nonwoven fabric was heated to 900°C in a nitrogen atmosphere over 40 minutes and held at this temperature for 3 minutes. Subsequently, activation treatment was carried out at that temperature for 17 minutes in a nitrogen stream containing water vapor with a dew point of 71°C, yielding an activated carbon fiber sheet.

[0114] (1.2) Preparation of water purification filters (water purification molded bodies) As a fibrous binder, 5 parts by weight of acrylic fiber 50TWF manufactured by Nippon Exlan Kogyo Co., Ltd. was prepared. Five parts by weight of the prepared fibrous binder was placed in a mixer together with 0.5 L of water and defibrated and dispersed for 30 seconds. Next, 100 parts by weight of the activated carbon fiber sheet obtained in (1.1) above and 0.5 L of water were added and defibrated and dispersed for another 10 seconds to obtain a first slurry. The first slurry was suction-molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than the activated carbon fiber sheet.

[0115] <Example 2> The same fibrous binder as used in Example 1 above was prepared. Five parts by weight of the prepared fibrous binder was placed in a mixer with 0.5 L of water and defibrated and dispersed for 30 seconds. Next, 100 parts by weight of granular activated carbon and 0.5 L of water were added and defibrated and dispersed for another 10 seconds to obtain a second slurry. 50 parts by weight each of the first and second slurries from Example 1 above were mixed, and this mixed slurry was suction molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than the activated carbon fiber sheet.

[0116] Example 3 The same first slurry as used in Examples 1 and 2 above and the same second slurry as used in Example 2 above were prepared. 25 parts by weight of the first slurry and 75 parts by weight of the second slurry were mixed, and the mixed slurry was suction molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than an activated carbon fiber sheet.

[0117] Example 4 (1.1) Preparation of activated carbon fiber sheet Rayon fiber (17 dtex, fiber length 76 mm) basis weight 400 g / m 2 The needle-punched nonwoven fabric was impregnated with a 6-10% aqueous solution of diammonium hydrogen phosphate, squeezed, and then dried to deposit 8-10% by weight. The resulting pretreated nonwoven fabric was heated to 900°C in a nitrogen atmosphere over 40 minutes and held at this temperature for 3 minutes. Subsequently, activation treatment was carried out at that temperature for 17 minutes in a nitrogen stream containing water vapor with a dew point of 71°C, yielding an activated carbon fiber sheet.

[0118] (1.2) Preparation of water purification filters (water purification molded bodies) As a fibrous binder, 5 parts by weight of acrylic fiber 50TWF manufactured by Nippon Exlan Kogyo Co., Ltd. was prepared. Five parts by weight of the prepared fibrous binder was placed in a mixer together with 0.5 L of water and defibrated and dispersed for 30 seconds. Next, 100 parts by weight of the activated carbon fiber sheet obtained in (1.1) above and 0.5 L of water were added and defibrated and dispersed for another 20 seconds to obtain a first slurry. The first slurry was suction-molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than the activated carbon fiber sheet.

[0119] <Example 5> The same fibrous binder as used in Example 4 above was prepared. Five parts by weight of the prepared fibrous binder was placed in a mixer with 0.5 L of water and defibrated and dispersed for 30 seconds. Next, 100 parts by weight of granular activated carbon and 0.5 L of water were added and defibrated and dispersed for another 10 seconds to obtain a second slurry. 50 parts by weight each of the first and second slurries from Example 4 above were mixed, and this mixed slurry was suction molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than the activated carbon fiber sheet.

[0120] Example 6 The same first slurry as used in Examples 4 and 5 above and the same second slurry as used in Example 5 above were prepared. 25 parts by weight of the first slurry and 75 parts by weight of the second slurry were mixed, and the mixed slurry was suction molded, dehydrated, and dried to obtain a molded product for water purification. The obtained molded product for water purification was less likely to lose its shape than an activated carbon fiber sheet.

[0121] Example 7 (1.1) Activated carbon fiber A cotton-like rayon fiber (56 dtex, fiber length 102 mm) was impregnated with a 6-10% aqueous solution of diammonium hydrogen phosphate, squeezed, and then dried to allow 8-10% by weight of the diammonium hydrogen phosphate to adhere. The resulting pretreated fiber was heated to 900°C in a nitrogen atmosphere over 45 minutes and held at this temperature for 3 minutes. Subsequently, the fiber was activated at that temperature for 17 minutes in a nitrogen stream containing water vapor with a dew point of 71°C, yielding activated carbon fiber. (1.2) Preparation of water purification filters (water purification molded bodies) A molded article for water purification was obtained in the same manner as in Example 4, except that the activated carbon fiber obtained in (1.1) above was used instead of the activated carbon fiber sheet. The obtained molded article for water purification was less likely to lose its shape than activated carbon fiber.

[0122] Example 8 The same first slurry as used in Example 7 and the same second slurry as used in Example 5 were prepared. 25 parts by weight of the first slurry and 75 parts by weight of the second slurry were mixed, and the mixed slurry was suction molded, dehydrated, and dried to obtain a molded article for water purification. The obtained molded article for water purification was less likely to lose its shape than activated carbon fiber.

[0123] <Comparative Example 1> (1.1) Preparation of activated carbon fiber sheet Rayon fiber (3.0 dtex, fiber length 60 mm) basis weight 300 g / m 2The needle-punched nonwoven fabric was impregnated with a 6 to 10% aqueous solution of diammonium hydrogen phosphate, squeezed, and then dried to allow 8 to 10% by weight of the pretreated nonwoven fabric to adhere. The temperature of the resulting pretreated nonwoven fabric was raised to 900°C in a nitrogen atmosphere over 38 minutes, and the fabric was subsequently activated at that temperature for 13 minutes in a nitrogen stream containing water vapor with a dew point of 60°C to obtain an activated carbon fiber sheet.

[0124] (1.2) Preparation of water purification filters (water purification molded bodies) As a fibrous binder, 5 parts by weight of acrylic fiber 50TWF manufactured by Nippon Exlan Kogyo Co., Ltd. was prepared. Five parts by weight of the prepared fibrous binder was placed in a mixer together with 0.5 L of water and defibrated and dispersed for 30 seconds, and then 100 parts by weight of the activated carbon fiber sheet obtained in (1.1) above and 0.5 L of water were added and defibrated and dispersed for another 60 seconds to obtain a first slurry. The first slurry was suction-molded, dehydrated, and dried to obtain a molded product for water purification.

[0125] <Comparative Example 2> A commercially available water purification filter (product name: FMH-B055C, manufactured by Z Industrial Co., Ltd.) was purchased and used as Comparative Example 2.

[0126] <Comparative Example 3> A commercially available water purification filter (product name: FMH-C055C, manufactured by Z Industrial Co., Ltd.) was purchased and used as Comparative Example 3.

[0127] <Measurement method> The water purification filters manufactured or obtained as described above and their materials were measured and evaluated for various items such as size, physical properties, and performance using the methods described below. Note that the various numerical values ​​defining the inventions presented in this disclosure can be determined using the following measurement and evaluation methods.

[0128] In the following measurements, the water purification filters (water purification molded articles) of Examples 1 to 8 and the water purification filter of Comparative Example 1 were prepared to the following dimensions. The water purification filters of Comparative Examples 2 and 3 also had the same dimensions as those below. Outer radius of the cross section perpendicular to the longitudinal axis of the cylindrical filter body: 3.25 cm Inner radius of the cross section perpendicular to the longitudinal axis of the cylindrical filter body: 1.5 cm Longitudinal length of cylindrical filter body: 25cm Filter body volume: 653cm 3

[0129] Furthermore, the basic physical properties related to adsorption performance of JIS K 1477 were referenced as the reference standard for the N2 adsorption BET analysis method for specific surface area, total pore volume, and average pore diameter. Furthermore, for the ultramicropore volume and micropore volume, the simulation analysis method using N2 adsorption GCMC (GCMC: Grand Canonical Monte Carlo method) was referenced as the reference standard.

[0130] (1) Specific surface area Approximately 30 mg of test sample was collected for measurement, vacuum dried at 200°C for 20 hours, weighed, and measured using a high-precision gas / vapor adsorption measuring device BELSORP-max II (Microtrac-Bell). The adsorption amount of nitrogen gas at the boiling point of liquid nitrogen (77 K) was measured at a relative pressure of 10 -8 Measurements were made in the range of order 0.990, and the adsorption isotherm of the sample was created. This adsorption isotherm was analyzed by the BET method, in which the analytical relative pressure range was automatically determined under the conditions of adsorption isotherm type I (ISO 9277), and the BET specific surface area per weight (unit: m 2 / g, and use this to calculate the specific surface area (unit: m 2 / g).

[0131] (2) Total pore volume The total pore volume (unit: cm) obtained by the one-point method from the result of the isothermal adsorption curve obtained in the above specific surface area section at a relative pressure of 0.960 was calculated. 3 / g) was calculated.

[0132] (3) Average pore diameter (also called average pore size) It was calculated using the following formula 3.

[0133] [Formula 3] Average pore diameter (unit: nm) = 4 × total pore volume × 10 3 ÷specific surface area

[0134] (4) Ultramicropore volume (V 0.7 ) The isothermal adsorption curve obtained in the above specific surface area section was analyzed by the GCMC method using the analysis software BELMaster attached to the high-precision gas / vapor adsorption analyzer BELSORP-max II (Microtrac BEL) with the following analysis settings: "Smoothing (moving average processing using one point before and after every point of the pore distribution analysis)", "Distribution function: No-assumption", "Pore size definition: Solid and Fluid Def. Pore Size", and "Kernel: Slit-C-Adsorption". From the pore distribution curve obtained during adsorption, the cumulative pore volume of 0.7 nm was read and used to calculate the ultramicropore volume (unit: cm). 3 / g).

[0135] (5) Micropore volume (V 2.0 ) The isothermal adsorption curve obtained in the above specific surface area section was analyzed by the GCMC method using the analysis software BELMaster attached to the high-precision gas / vapor adsorption analyzer BELSORP-max II (Microtrac BEL) with the following analysis settings: "Smoothing (moving average processing using one point before and after every point of the pore distribution analysis)", "Distribution function: No-assumption", "Pore size definition: Solid and Fluid Def. Pore Size", and "Kernel: Slit-C-Adsorption". From the pore distribution curve obtained during adsorption, the cumulative pore volume of 2.0 nm was read and used to calculate the micropore volume (unit: cm). 3 / g).

[0136] (6) The pore volume (V) of pores with a pore diameter of more than 0.7 nm and less than 2.0 nm 0.7-2.0 ) The pore volume V is calculated by subtracting the ultramicropore volume (a) calculated in (4) above from the micropore volume (b) calculated in (5) above. 0.7-2.0 The value of was calculated.

[0137] (7) The ratio of the volume of ultramicropores to the volume of micropores (R 0.7 / 2.0 ) The ultramicropore volume (a) obtained in (4) above is divided by the micropore volume (b) obtained in (5) above to obtain the ultramicropore volume abundance ratio R 0.7 / 2.0 The value of was calculated.

[0138] (8) Basis weight of activated carbon fiber sheet used as material for water purification filter Each test sample to be measured is left to stand for 12 hours or more in an environment of 23±2°C temperature and 50±5% relative humidity, and the basis weight (unit: g / m2) is calculated from the weight and length and width dimensions. 2 ) was sought.

[0139] (9) Thickness of activated carbon fiber sheet used as material for water purification filter Each test sample to be measured was left to stand for at least 12 hours in an environment with a temperature of 23±2°C and a relative humidity of 50±5%, and the sheet thickness (unit: mm) was measured when a load of 0.3 kPa was applied using a small digital thickness gauge FS-60DS (Daiei Scientific Instruments Manufacturing Co., Ltd.).

[0140] (10) Humidity Control Density The conditioned density of each test sample was calculated using the following formula 4. The sheet weight and sheet thickness were determined by the measurements in (8) and (9) above, respectively.

[0141] [Formula 4] Humidity density (unit: g / cm 3 ) = Sheet basis weight ÷ Sheet thickness ÷ 10 3

[0142] (11) Moisture content The test sample to be measured was left to stand for 12 hours or more in an environment with a temperature of 23±2°C and a relative humidity of 50±5%, and then 0.5 to 1.0 g of the sample was taken and dried in a dryer at 115±5°C for 3 hours or more. The moisture content (unit: %) was calculated from the change in weight.

[0143] (12) Fiber diameter and fiber length of activated carbon fiber The average value, standard deviation, and coefficient of variation of the fiber diameter and fiber length of the activated carbon fibers contained in the water purification filter were determined as follows.

[0144] <Average fiber diameter> The fiber diameter was measured using a scanning electron microscope JSM-IT300 InTouchScope (manufactured by JEOL Ltd.), where 10 fibers were randomly selected from an image at 500x magnification, and the average fiber diameter was calculated by measuring the fibers.

[0145] <Average fiber length> Fiber length was measured using a DIGITAL MICROSCOPE KH-8700 (Hirox Co., Ltd.) by randomly extracting 20 fibers from a 50x image and measuring them to determine the average fiber length.

[0146] <Fiber length / standard deviation> Fiber length was measured using a DIGITAL MICROSCOPE KH-8700 (Hirox Corporation) by randomly selecting 20 fibers from a 50x image, measuring them, and then calculating the standard deviation.

[0147] <Fiber length / coefficient of variation> Calculated by dividing the standard deviation by the mean value.

[0148] (13) Particle size of granular activated carbon The mean value, standard deviation, and coefficient of variation of the particle size of the granular activated carbon contained in the water purification filter were determined as follows.

[0149] <Average particle size> The fiber length was measured using a Digital Microscope KH-8700 (Hirox Corporation) by randomly selecting 20 granular activated carbon particles from a 50x image, measuring them, and then calculating the average particle diameter.

[0150] <Particle size / standard deviation> Fiber length was measured using a DIGITAL MICROSCOPE KH-8700 (Hirox Corporation) by randomly selecting 20 granular activated carbon particles from a 50x image and measuring them, then calculating the standard deviation of particle diameter.

[0151] <Particle size / coefficient of variation> It was calculated by dividing the standard deviation of particle size by the average particle size.

[0152] (14) Measurement of water purification filters The water purification filters (molded bodies for water purification) of Examples 1 to 8 and Comparative Examples 1 to 3 were left to stand for 12 hours or more in an environment of 23±2°C temperature and 50±5% relative humidity, and then the sizes of the molded bodies were measured using calipers and a ruler. The weights of the molded bodies were also measured using an electronic balance.

[0153] (15) Density of water purification filter (humidity-controlled density: temperature 23°C, relative humidity 50%) It was calculated using the following formula 5. [Formula 5] Density (unit: g / cm 3 ) = Weight of water purification filter ÷ Volume of molded product × 100

[0154] The volume and weight of each water purification filter were determined using the measurements of the molded body described above in (14).

[0155] (16) Methylene blue adsorption performance The methylene blue decolorizing power (unit: ml / g) of powdered activated carbon for water supply (JWWA K113) was measured according to the Japan Water Works Association standard and the result was taken as the methylene blue adsorption performance (unit: ml / g).

[0156] (17) Residual chlorine concentration The test sample water purification filter was loaded into a 250mm housing, and water adjusted to a residual chlorine concentration of 50 ppm using sodium hypochlorite at 20°C was passed through it from the outside to the inside at a flow rate of 4 L / min. Afterwards, a sample was taken and the residual chlorine concentration (ppm) was measured using a portable residual chlorine meter HI 96771 (Hanna Instruments Japan). When the residual chlorine concentration was between 0 and 5.00 ppm, a DPD (diethyl-p-phenylenediamine) reagent was used, and when it was above 5.00 ppm, a potassium iodide reagent was used for absorption spectrometry.

[0157] (18) Pressure loss The test sample water purification filter was packed into a 250mm housing, and water adjusted to 20°C with a residual chlorine concentration of 50 ppm using sodium hypochlorite was passed from the outside to the inside at a flow rate of 4 L / min, and the pressure loss (MPa) before and after passing was measured.

[0158] The measurement results for Examples 1 to 8 and Comparative Examples 1 to 3 are shown in Tables 1, 2-1, 2-2, 2-3, and 2-4. In the tables, the term "ACF" is an abbreviation for activated carbon fiber.

[0159] [Table 1]

[0160] [Table 2-1]

[0161] [Table 2-2]

[0162] [Table 2-3]

[0163] [Table 2-4] [Explanation of symbols]

[0164] 1: Water purification cartridge, 11: Cylindrical body (molded body for water purification), 12: End cap 11a: Inner circumference, 11b: Outer circumference, X-X': Axis center line (center line)

Claims

1. A molded body for water purification, the molded body includes activated carbon and a fibrillated fibrous binder; The content ratio of the activated carbon to the fibrous binder is 0.3 to 20 parts by weight of the fibrous binder per 100 parts by weight of the activated carbon; The activated carbon contains 20 parts by weight or more of activated carbon fiber per 100 parts by weight of the activated carbon, The average fiber length / average fiber diameter of the activated carbon fibers is 15.38 to 40. Molded body.

2. The molded article according to claim 1, wherein the activated carbon fibers have an average fiber length of 500 μm or more.

3. The molded article according to claim 1 , wherein the activated carbon fibers have an average fiber diameter of 12.0 μm or more.

4. 2. The molded article according to claim 1, wherein the activated carbon fibers have an average fiber length of 500 μm or more and an average fiber diameter of 13.0 μm or more.

5. 2. The molded body according to claim 1, wherein the activated carbon comprises 20 to 90 parts by weight of the activated carbon fiber and 80 to 10 parts by weight of granular activated carbon per 100 parts by weight of the activated carbon.

6. The molded body according to claim 5, wherein the average particle size of the granular activated carbon is 40 to 2000 μm.

7. 2. The molded body according to claim 1, wherein the fineness of the fiber material serving as the precursor of the activated carbon fiber is 3.3 to 60.0 dtex.

8. The specific surface area of ​​the molded body is 1100 to 2400 m 2 The molded article according to claim 1, wherein the molecular weight is 1 / g.

9. The total pore volume of the molded body is 0.50 to 1.20 cm 3 The molded article according to claim 1, wherein the molecular weight is 1 / g.

10. The density of the molded body is 0.06 to 0.40 g / cm 3 The molded article according to claim 1 ,

11. The specific surface area of ​​the molded body is 1100 to 2400 m 2 / g, and the total pore volume of the molded body is 0.50 to 1.20 cm 3 / g, and the density of the molded body is 0.06 to 0.40 g / cm 3 The molded article according to claim 1 ,

12. The molded body according to claim 1, wherein the pressure loss of the molded body is 0.00005 MPa or more and 0.0020 MPa or less.

13. The molded body according to any one of claims 1 to 12, which is a molded product of a mixture containing defibrated fibers of the activated carbon fiber and the fibrous binder.

14. The molded body described in claim 5 or 6, which is a molded product of a mixture containing defibrated fibers of the activated carbon fiber, the fibrous binder, and the granular activated carbon.

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