Water purification filter

Abstract

To provide a technique capable of contributing to environmental load reduction while securing performance as a water purification filter.SOLUTION: The water purification filter 11 satisfies at least one of the conditions that the increase in CO2 on the ground surface due to CO2 released at the time of disposal is not more than 240L per kilogram and that the use rate of petroleum-derived raw materials is not more than 15%.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to water filters. [Background technology]

[0002] Patent Document 1 discloses a water purification filter in which activated carbon molded bodies are filled in a housing. As a specific example of the water purification filter, it describes that acrylic fibers are used as a fibrous binder for the activated carbon molded bodies, and the activated carbon molded bodies are loaded into a plastic housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-136589 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, efforts to reduce the environmental impact of various products have been underway. Technologies to reduce the environmental impact of water purification filters are also desired. However, water purification filters are products that require various performance characteristics, such as productivity, durability, and safety, in addition to filtration performance, making it difficult to reduce the environmental impact.

[0005] The present disclosure has been made in consideration of the above-mentioned conventional situation, and aims to solve the problem of providing a water purification filter that can contribute to reducing environmental impact while ensuring performance as a water purification filter. [Means for solving the problem]

[0006] The water purification filter of the present disclosure satisfies at least one of the following: the increase in CO2 at the ground surface due to CO2 released upon disposal is 240 L or less per kilogram; and the usage rate of petroleum-derived raw materials is 15% or less. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an explanatory diagram illustrating a schematic configuration of a molded adsorbent body. [Figure 2] FIG. 1 is a front view of an example of a water purification filter including a molded adsorbent. [Figure 3] FIG. 3 is a cross-sectional view of the water purification filter of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0008] Embodiments of the present disclosure will be described with reference to the drawings. In this specification, when a numerical range is described using "greater than or equal to" or "less than or equal to," the range includes both the lower and upper limits, unless otherwise specified. For example, the expression "10 or greater and 20 or less" includes both the lower limit "10" and the upper limit "20." Furthermore, in this specification, the upper and lower limits of each numerical range can be combined in any combination.

[0009] The water purification filter 11 of this embodiment satisfies at least one of the following requirements: the increase in CO2 at the ground surface due to CO2 released when disposed of is 240 L or less per kilogram; and the usage rate of petroleum-derived raw materials is 15% or less. An example of the water purification filter 11 is shown in Figures 1 to 3.

[0010] The shape and structure of the water purification filter 11 are not particularly limited. As shown in Figures 2 and 3, an example of the water purification filter 11 is cylindrical. This water purification filter 11 includes a core material 12, a molded adsorbent 1, a support 14, and caps 15 and 16. The core material 12 is hollow and cylindrical. The core material 12 has pores formed therein that allow water to pass from the outside to the inside, and a flow path 20 is formed therein. Any material can be used for the core material 12. It is preferable that the core material 12 not be made of a petroleum-derived material. The material of the core material 12 is, for example, a mineral-derived porous ceramic or a mineral-derived porous metal filter.

[0011] The molded adsorbent body 1 in one example is cylindrical and is disposed on the outer peripheral surface of the core material 12. The support 14 is disposed on the outer peripheral surface of the molded adsorbent body 1.

[0012] The cap 15 is a sealing cap. The cap 15 is in contact with the bottom surface of the molded adsorbent 1 in a watertight manner. The cap 16 is also a sealing cap. The cap 16 is in contact with the top surface of the molded adsorbent 1 in a watertight manner. The cap 16 has an outlet 60 through which water that has flowed through the flow path 20 is discharged. The caps 15 and 16 are, for example, injection-molded products.

[0013] Cap 15 is an example of a resin part. Cap 16 is another example of a resin part. Caps 15 and 16 may be made of the same material or different materials. In the water purification filter 11, it is preferable that at least one of cap 15 and cap 16 contains resin A, which will be described later, and it is more preferable that both contain resin A. Below, we will explain cap 15 containing resin A, and will omit explanation of cap 16 containing resin A.

[0014] From the viewpoint of ensuring performance as a water purification filter, resin A is preferably one or more selected from the group consisting of polyhydroxybutyrate / hydroxyhexanoate (PHBH) resin and biomass-derived polyolefin resin. Polyhydroxybutyrate / hydroxyhexanoate (PHBH) resin is a polyester resin contained in microbial metabolites. Biomass-derived polyolefin resin is synthesized using, for example, biomass-derived alcohol. Biomass-derived alcohol is, for example, plant-derived alcohol, specifically corn-derived alcohol. The olefin monomer constituting the polyolefin resin is, for example, one or more selected from the group consisting of ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Polyolefin resins are preferably polyethylene or polypropylene. Biomass-derived polyolefin resins are generally not biodegradable. From the viewpoint of biodegradability, resin A is more preferably a polyhydroxybutyrate / hydroxyhexanoate (PHBH) resin.

[0015] In the present disclosure, the term "biomass-derived" means that at least a portion of the raw material is a biomass raw material, such as a plant raw material.

[0016] From the viewpoint of carbon neutrality, the biomass content in the cap 15 is preferably 35% or more, more preferably 50% or more, even more preferably 60% or more, and particularly preferably 70% or more. The upper limit of the biomass content in the cap 15 is 100%.

[0017] In the present disclosure, the biomass content is the proportion of the mass of biomass-derived raw materials to the mass of the entire raw materials, and is calculated using the following formula: The biomass contents of other components can be calculated in a similar manner.

[0018] Biomass content (%) = (mass of biomass-derived raw material / mass of total raw material) x 100

[0019] There are no particular limitations on the mass ratio of the caps 15, 16 to the entire water purification filter 11. The mass ratio of the caps 15, 16 to the entire water purification filter 11 may be, for example, 0.5% by mass or more and 50% by mass or less, 4% by mass or more and 30% by mass or less, or 10% by mass or more and 25% by mass or less. The mass of the entire water purification filter 11 in this embodiment is the sum of the masses of the core material 12, the molded adsorbent body 1, the support 14, and the caps 15, 16.

[0020] As shown in Fig. 1, the formed adsorbent 1 of this embodiment contains, for example, activated carbon 3 and a fibrous binder 7. The formed adsorbent 1 may further contain one or more lead removal materials 5 selected from the group consisting of zeolite, titanium silicate, sodium titanate, aluminosilicate, and titanium oxide. Fig. 1 is an explanatory diagram schematically showing the configuration of the formed adsorbent 1. The size, shape, and amount of each component are not limited to those shown.

[0021] The activated carbon 3 can be obtained from any starting material. Specific examples of the activated carbon 3 include activated carbon obtained from biomass materials such as fruit shells, bamboo, and rice husks, and activated carbon obtained from petroleum-derived materials such as coal and resin. Examples of fruit shells include coconut shells, walnut shells, peach seed shells, and plum seed shells. The activated carbon 3 may contain activated carbon obtained from petroleum-derived materials, provided that the effects of the present disclosure are not impaired. Even when activated carbon obtained from petroleum-derived materials is included, it is desirable to reduce the content of activated carbon obtained from petroleum-derived materials as much as possible. It is preferable that the activated carbon 3 does not contain activated carbon obtained from petroleum-derived materials, and it is more preferable that the activated carbon 3 contains only activated carbon obtained from biomass materials. The form of the activated carbon 3 is not particularly limited. The activated carbon 3 is, for example, in a granular form.

[0022] From the viewpoint of carbon neutrality, the biomass content in the activated carbon 3 is preferably 35% or more, more preferably 40% or more, even more preferably 50% or more, and particularly preferably 60% or more. The upper limit of the biomass content in the activated carbon 3 may be 100%.

[0023] The mass ratio of the activated carbon 3 to the entire water purification filter 11 is not particularly limited. The mass ratio of the activated carbon 3 to the entire water purification filter 11 may be, for example, 40% by mass or more and 85% by mass or less, 45% by mass or more and 75% by mass or less, 50% by mass or more and 65% by mass or less, or 50% by mass or more and 60% by mass or less. In this embodiment, the mass of the entire water purification filter 11 is the sum of the masses of the core material 12, the molded adsorbent body 1, the support 14, and the caps 15 and 16.

[0024] From the viewpoint of carbon neutrality, the fibrous binder 7 preferably contains at least a fibrous binder that does not use a petroleum-derived material, and more preferably contains at least a plant-derived fibrous binder. A specific example of the fibrous binder 7 is cellulose fiber. The raw material for the cellulose fiber may be, for example, one or more selected from the group consisting of wood pulp and non-wood plant pulp. The fibrous binder 7 may contain a petroleum-derived fibrous binder as long as the effects of the present disclosure are not impaired. Even when a petroleum-derived fibrous binder is contained, it is desirable to reduce the content of the petroleum-derived fibrous binder as much as possible. From the viewpoint of carbon neutrality, the molded adsorbent 1 preferably does not contain a petroleum-derived fibrous binder, and more preferably contains only a plant-derived fibrous binder.

[0025] From the viewpoint of carbon neutrality, the biomass content in the fibrous binder 7 is preferably 35% or more, more preferably 50% or more, even more preferably 60% or more, and particularly preferably 70% or more. The upper limit of the biomass content in the fibrous binder 7 may be 100%.

[0026] There are no particular limitations on the mass ratio of the fibrous binder 7 to the entire water purification filter 11. The mass ratio of the fibrous binder 7 to the entire water purification filter 11 may be, for example, 0.5% by mass or more and 20% by mass or less, 1% by mass or more and 10% by mass or less, or 2% by mass or more and 5% by mass or less. The mass of the entire water purification filter 11 in this embodiment is the sum of the masses of the core material 12, the molded adsorbent body 1, the support 14, and the caps 15 and 16.

[0027] The lead removal material 5 is not particularly limited as long as the desired effect is not impaired. It is preferable that the lead removal material 5 does not use a petroleum-derived material. The lead removal material 5 is, for example, one or more selected from the group consisting of zeolite, titanium silicate, sodium titanate, aluminosilicate, and titanium oxide. The form of the lead removal material 5 is not particularly limited. The lead removal material 5 is, for example, in a particulate form.

[0028] There are no particular limitations on the mass ratio of the lead removal material 5 to the entire water purification filter 11. The mass ratio of the lead removal material 5 to the entire water purification filter 11 may be, for example, 0.5% by mass or more and 10% by mass or less, 1% by mass or more and 8% by mass or less, or 2% by mass or more and 5% by mass or less. The mass of the entire water purification filter 11 in this embodiment is the sum of the masses of the core material 12, the molded adsorbent 1, the support 14, and the caps 15 and 16.

[0029] The filtration flow rate of the formed adsorbent 1 is preferably 1.5 L / min or more, more preferably 2.0 L / min or more, and even more preferably 2.5 L / min or more. There are no particular limitations on the upper limit of the filtration flow rate of the formed adsorbent 1, and it is, for example, 3.5 L / min or less. The filtration flow rate of the formed adsorbent 1 can be measured in accordance with JIS S3201 6.1 "Filtration Flow Rate Test."

[0030] The turbidity removal rate of the formed adsorbent 1 is preferably 80% or more, and more preferably 85% or more. There is no particular upper limit to the turbidity removal rate of the formed adsorbent 1, and it may be, for example, 100%. The water permeability of the formed adsorbent 1 can be measured in accordance with JIS S3201 6.4.3 "Turbidity removal performance test."

[0031] The support 14 is made of, for example, a nonwoven fabric, and may be made of, for example, a nonwoven fabric specified in JIS L0222.

[0032] From the viewpoint of carbon neutrality, it is preferable that the nonwoven fabric use as little petroleum-derived raw materials as possible. Furthermore, from the viewpoint of ensuring performance as a water purification filter, it is more preferable that the nonwoven fabric contains one or more fibers selected from the group consisting of biomass-derived cellulose fibers and biomass-derived polyolefin resin fibers. Examples of cellulose fiber raw materials include wood pulp and non-wood plant pulp. The explanation of the biomass-derived polyolefin resin is the same as that of the biomass-derived polyolefin resin described in Resin A. From the viewpoint of biodegradability, it is more preferable that the nonwoven fabric contains biomass-derived cellulose fibers. From the viewpoint of achieving both biodegradability and mechanical strength, it is even more preferable that the nonwoven fabric contains polyolefin resin fibers and biomass-derived cellulose fibers.

[0033] From the viewpoint of carbon neutrality, the biomass content in the nonwoven fabric is preferably 35% or more, more preferably 50% or more, and even more preferably 60% or more. The upper limit of the biomass content in the nonwoven fabric may be 100%, 90% or less, or 80% or less.

[0034] There are no particular limitations on the mass ratio of the nonwoven fabric to the entire water purification filter 11. The mass ratio of the nonwoven fabric to the entire water purification filter 11 may be, for example, 0.1 mass% to 10 mass%, 0.5 mass% to 5 mass%, or 0.8 mass% to 2 mass%. The mass of the entire water purification filter 11 in this embodiment is the sum of the masses of the core material 12, the molded adsorbent body 1, the support 14, and the caps 15 and 16.

[0035] The water purification filter includes an adhesive layer made of an adhesive. The components in the water purification filter that are bonded by the adhesive layer are not particularly limited. The adhesive layer in the water purification filter 11 of this embodiment is, for example, an adhesive layer that bonds the caps 15 and 16 to the assembly of the core material 12, the molded adsorbent body 1, and the support 14. Note that the adhesive layer is not shown in Figures 2 and 3.

[0036] From the viewpoint of carbon neutrality, it is preferable that the adhesive use as little petroleum-derived raw materials as possible, and more preferably contains one or more selected from the group consisting of biomass-derived polyamide resins, biomass-derived rosin-based resins, and biomass-derived polyolefin resins. Biomass-derived polyamide resins are, for example, polyamides in which biomass raw materials are used for at least one of the acid component and amine component of the raw material. Rosin is a natural resin obtained from the sap of plants in the pine family. Rosin-based resins are preferably rosin derivatives obtained by modifying rosin, and more preferably rosin esters. The explanation of biomass-derived polyolefin resins described in Resin A applies as is to the explanation of biomass-derived polyolefin resins.

[0037] From the viewpoint of carbon neutrality, the biomass content in the adhesive is preferably 35% or more, more preferably 45% or more, and even more preferably 50% or more. The upper limit of the biomass content in the adhesive may be 100%, 90% or less, or 80% or less.

[0038] There are no particular limitations on the mass ratio of the adhesive layer to the entire water purification filter 11. The mass ratio of the adhesive layer to the entire water purification filter 11 may be, for example, 0.1% by mass to 10% by mass, 0.5% by mass to 5% by mass, or 1% by mass to 3% by mass. The mass of the entire water purification filter 11 in this embodiment is the sum of the masses of the core material 12, the molded adsorbent body 1, the support 14, and the caps 15 and 16.

[0039] The water purification filter 11 preferably increases the amount of CO2 released at the ground surface upon disposal by 240 L or less per kilogram, more preferably 200 L or less, even more preferably 160 L or less, and particularly preferably 120 L or less, 80 L or less, 40 L or less, or 25 L or less. The lower limit of the CO2 increase is not particularly limited and may be 0 L, or may be, for example, 5 L or more, or 10 L or more.

[0040] The increase in CO2 emissions from a water filter can be calculated by adding up the amount of CO2 released from the petroleum-derived raw materials that make up the filter. The amount of CO2 released from petroleum-derived raw materials (L) is calculated using the following formula:

[0041] Amount of CO2 released from petroleum-derived materials = (W / M) x number of carbon atoms x 22.4

[0042] In the above formula, W represents the mass (g) of the petroleum-derived raw material contained in the water purification filter. M represents the molar mass (g / mol) of the constituent unit of the petroleum-derived raw material. The carbon number is the number of carbon atoms in the unit that constitutes the petroleum-derived raw material. The volume of 1 mole of carbon dioxide is 22.4 L.

[0043] For example, the amount of CO2 released from 3.4 g of petroleum-derived polypropylene is calculated as (3.4 / 42) x 3 x 22.4, which is 5.4 L. The amount of CO2 released from 0.9 g of petroleum-derived acrylonitrile fiber is calculated as (0.9 / 53.06) x 3 x 22.4, which is 1.1 L.

[0044] Biomass-derived raw materials also release CO2 when disposed of. However, because biomass-derived raw materials are produced by absorbing CO2 from the atmosphere, the atmospheric CO2 circulates and does not increase CO2 on the earth's surface when disposed of. The increase in CO2 on the earth's surface due to CO2 released during disposal can be reduced by replacing petroleum-derived raw materials with non-petroleum-derived raw materials. Examples of non-petroleum-derived raw materials include biomass-derived raw materials and mineral-derived raw materials. These non-petroleum-derived raw materials are also referred to as carbon-neutral raw materials hereinafter.

[0045] The water purification filter 11 preferably has a petroleum-derived raw material usage rate of 15% or less, more preferably 12% or less, even more preferably 10% or less, even more preferably 8% or less, and particularly preferably 5% or less. The lower limit of the petroleum-derived raw material usage rate may be 0%.

[0046] The usage rate of the petroleum-derived raw materials can be calculated as the mass ratio of the petroleum-derived raw materials to the entire water purification filter 11. Raw materials other than petroleum-derived raw materials in the water purification filter 11 include, for example, biomass-derived raw materials and mineral-derived raw materials. The usage rate of the petroleum-derived raw materials can be reduced by replacing the petroleum-derived raw materials with biomass-derived raw materials. The usage rate of the petroleum-derived raw materials can also be reduced by replacing the petroleum-derived raw materials with mineral-derived raw materials.

[0047] The utilization rate of biomass-derived raw materials in the water purification filter 11 is preferably 65% ​​or more, more preferably 70% or more, and even more preferably 75% or more, and the upper limit of the above-mentioned utilization rate of biomass-derived raw materials may be 100%, or may be 95% or less, or 90% or less.

[0048] There are no particular limitations on the manufacturing method of the water purification filter 11. The manufacturing method of the water purification filter 11 includes, for example, a mixing step, a suction molding step, a drying step, a surface polishing step, a nonwoven fabric winding step, and a sealing step.

[0049] The mixing step involves mixing at least activated carbon 3, fibrous binder 7, and water to obtain a slurry. The suction molding step involves molding a molded adsorbent 1. For example, the suction molding step includes sealing the other end of the flow path 20 of the core material 12 and connecting one end of the flow path 20 of the core material 12 to a suction pump via a hose; immersing the core material 12 connected to the suction pump in the above-mentioned slurry stored in a container and operating the suction pump; and allowing the water in the slurry to permeate the core material 12, leaving a mixture of activated carbon 3 and fibrous binder 7 on the surface of the core material 12 and gradually depositing it. The water in the slurry sucked into the suction pump is discharged through a drainage channel. Operating the suction pump allows the molded adsorbent 1 to be formed to a specified thickness.

[0050] In the drying step, the formed adsorbent body 1 formed in the suction forming step is dried. In the surface polishing step, the outer peripheral surface of the formed adsorbent body 1 is polished. In the nonwoven fabric winding step, a support 14 is wrapped around the outer peripheral surface of the formed adsorbent body 1 polished in the surface polishing step. In the sealing step, a cap 15 is attached to one end of the formed adsorbent body 1 around which the support 14 is wrapped, and a cap 16 is attached to the other end.

[0051] As described above, the water purification filter 11 of this embodiment satisfies at least one of the following requirements: the increase in CO2 at the ground surface due to CO2 released at the time of disposal is 240 L or less per kilogram; and the usage rate of petroleum-derived raw materials is 15% or less. The water purification filter 11 of this embodiment is carbon neutral, which contributes to reducing the environmental burden. The water purification filter 11 of this embodiment excels in at least one of filtration performance, productivity, durability, and safety, and is therefore practical. [Example]

[0052] The experimenters conducted tests to select materials with minimal environmental impact for each part of the water purification filter. Specifically, the experimenters conducted various tests on material samples for the cap, fibrous binder, nonwoven fabric, and adhesive, for which it is particularly desirable to replace petroleum-derived materials with biomass-derived materials. Details of the material samples are listed in Tables 1, 3, 5, and 7. Each component in the table represents the following compound. PLA: Polylactic acid PBAT: Polybutylene adipate co-terephthalate PBS: Polybutylene succinate PHBH: Polyhydroxybutyrate / hydroxyhexanoate resin Biomass PE: polyethylene derived from biomass PP: Polypropylene PET: Polyethylene terephthalate PA: Polyamide resin

[0053] The common test items for the cap, fibrous binder, nonwoven fabric, and adhesive were "environmental impact" and "safety." For "environmental impact," the biomass raw material content (mass%) and biodegradable raw material content (mass%) were calculated based on information provided by the manufacturer. If the biomass raw material content (mass%) was 35% or higher, it was deemed suitable as a raw material to be used, and if it was less than 35%, it was deemed unsuitable. The results are shown in the "biomass ratio" and "biodegradability" columns in Tables 2, 4, 6, and 8.

[0054] For "safety," a water purification filter was fabricated and tested in accordance with JIS S3200-7 "Water Supply Appliances - Leaching Performance Test Method." The structure of the water purification filter will be explained later. When evaluating the safety of each part, only one of the cap, nonwoven fabric, fiber binder, or adhesive was replaced with a new material, and the evaluation was conducted. The other parts were constructed with materials whose leaching test values ​​were known or which passed with a margin. If the leaching performance test was passed, it was deemed suitable as a raw material for use; if it failed, it was deemed unsuitable as a raw material for use. The results are shown in the "Safety Leaching Test" column in Tables 2, 4, 6, and 8.

[0055] The "productivity" of the cap was judged based on whether it could be injection molded and whether it could be colored. If it could be injection molded, it was judged to have good productivity, and if it could not be injection molded, it was judged to have poor productivity. If it could be colored, it was judged to have good productivity, and if it could not be colored, it was judged to have poor productivity. The results are shown in the "Injection molding" and "Coloring" columns of "Productivity" in Table 2.

[0056] The "durability" of the caps was judged by tensile strength, hot water resistance evaluation, and biodegradation risk evaluation. Tensile strength was evaluated by a tensile strength test in which the caps were processed into the shape of a water purification filter and the tensile strength in the longitudinal direction was measured. If the tensile strength was 30N or more, it was judged to have good tensile strength, and if the tensile strength was less than 30N, it was judged to have poor tensile strength. Hot water resistance was evaluated by (1) the above tensile strength test and (2) the above leaching test after immersion in 80°C hot water for 12 hours. If the tensile strength after immersion in hot water was 30N or more, it was judged to have good hot water resistance, if the tensile strength was 20N or more but less than 30N, it was judged to have fair hot water resistance, and if the tensile strength was less than 20N, it was judged to have poor hot water resistance. The biodegradation risk evaluation was carried out by (1) extracting 100g of organic potting soil from the organic potting soil. 5 A bacterial solution containing colony-forming units (CFUs) was prepared and immersed in the bacterial solution for four weeks at room temperature. Evaluations were then made using (1) the tensile strength test described above and (2) the leaching test described above. For the tensile strength test (1), the filter was immersed in the bacterial solution after being processed into a water purification filter. For the leaching test (2), the filter was immersed in the bacterial solution as a part, removed from the solution after a certain period of time, and then processed into a water purification filter. If the tensile strength after immersion in the bacterial solution was 30 N or greater and the filter passed the leaching test, the biodegradation risk assessment was deemed good. If the tensile strength was less than 30 N or the filter failed the leaching test, the biodegradation risk assessment was deemed poor. The results are shown in the "Durability" columns of Table 2, "Tensile Strength," "Hot Water Resistance," and "Biodegradation Risk Assessment."

[0057] The "productivity" of the fiber binder was judged based on its dispersibility in water. If it was dispersible in water, it was judged to have good productivity, and if it was not dispersible in water, it was judged to have poor productivity. The results are shown in the "Productivity" column of Table 4.

[0058] The "durability" of the fiber binder was judged based on tensile strength, warm water resistance, and biodegradation risk assessment. Tensile strength was evaluated by a tensile strength test in which a molded adsorbent was fabricated and processed into a water purification filter, and the tensile strength in the longitudinal direction was measured. A tensile strength of 30 N or greater was considered good, and a tensile strength of less than 30 N was considered poor. Warm water resistance was evaluated in the same way as the cap. The biodegradation risk assessment was evaluated in the same way as the cap, except that (1) the above tensile strength test and (2) the above leaching test were performed after the binder was processed into a water purification filter. The results are shown in the "Tensile Strength," "Warm Water Resistance," and "Biodegradation Risk Assessment" columns under "Durability" in Table 4.

[0059] The "productivity" of nonwoven fabrics was judged based on whether or not they could be welded together. If the nonwoven fabrics could be welded together, they were judged to have good productivity, and if they could not be welded together, they were judged to have poor productivity. The results are shown in the "Productivity" column of Table 6.

[0060] The "durability" of nonwoven fabrics was assessed based on tensile strength, hot water resistance, and biodegradation risk. Tensile strength was assessed by a tensile strength test in which the nonwoven fabric was pulled in one direction to measure the tensile strength. If the nonwoven fabric was anisotropic, it was measured in two directions: in a random direction and in a direction tilted 90 degrees from the random direction, and the larger tensile strength was used for evaluation. A tensile strength of 30 N or greater was judged to have good tensile strength, and a tensile strength of less than 30 N was judged to have poor tensile strength. Hot water resistance was assessed by immersing the fabric in 80°C hot water for 12 hours, followed by (1) the tensile strength test described above and (2) the leaching test described above. A tensile strength of 30 N or greater after hot water immersion was judged to have good hot water resistance, and a tensile strength of less than 30 N was judged to have poor hot water resistance. The biodegradation risk assessment was conducted in the same manner as for the cap, except that (1) the above tensile strength test was conducted on the nonwoven fabric as is, and (2) the above leaching test was conducted on the nonwoven fabric after it had been processed into a water purification filter. The results are shown in the "Tensile strength," "Warm water resistance," and "Biodegradation risk assessment" columns under "Durability" in Table 6.

[0061] The "productivity" of an adhesive was judged based on whether or not it could bond the adherends. If the adherends could be bonded, it was judged to have good productivity, and if the adherends could not be bonded, it was judged to have poor productivity. The results are shown in the "Productivity" column of Table 8.

[0062] The "durability" of the adhesive was judged based on tensile strength, warm water resistance, and biodegradation risk. Tensile strength was evaluated by a tensile strength test in which a molded adsorbent was fabricated and processed into a water purification filter, and the longitudinal tensile strength was measured. A tensile strength of 30 N or greater was considered good, and a tensile strength of less than 30 N was considered poor. Warm water resistance was evaluated in the same way as the cap. The biodegradation risk was evaluated in the same way as the cap, except that (1) the above tensile strength test and (2) the above leaching test were performed after the product was processed into a water purification filter. The results are shown in the "Tensile Strength," "Warm Water Resistance," and "Biodegradation Risk Assessment" columns under "Durability" in Table 8.

[0063] The cap, fibrous binder, nonwoven fabric, and adhesive were comprehensively evaluated for "productivity," "durability," "safety," and "environmental impact." The evaluation criteria are as shown in Tables 2, 4, 6, and 8. For example, two "good" ratings for "productivity" mean that two items in the productivity test were judged to be "good." Based on these comprehensive evaluations, the final preferred material was selected. The selected material was marked with an "A" or "B" in the "Final Judgment" column. "A" indicates that the material is more preferable than "B." The results are shown in the "Overall Evaluation" column of Tables 2, 4, 6, and 8.

[0064] [Table 1]

[0065] [Table 2]

[0066] [Table 3]

[0067] [Table 4]

[0068] [Table 5]

[0069] [Table 6]

[0070] [Table 7]

[0071] [Table 8]

[0072] Next, the experimenter produced water purification filters of Examples 1 to 4 and a comparative example. Each water purification filter was produced using the raw materials listed in the "Raw material type" column of Table 10, in the amounts listed in the "Amount used (g)" column. Details of the raw materials are as follows:

[0073] The cap of Example 1 was made of a biomass-derived polyolefin-containing resin, a mixture of sugarcane-derived polyethylene (PE) and petroleum-derived polypropylene (PP), SHA7260, manufactured by Toyota Tsusho Corporation, as shown in #14 of Tables 1 and 2. The biomass raw material content (mass%) of the cap of Example 1 was 94%.

[0074] The fibrous binder used in Example 1 was the cellulose fiber listed in #4 of Tables 3 and 4, Celish PC110S manufactured by Daicel Corporation, and the cellulose fiber listed in #7, nano forest-S BS manufactured by Chuetsu Pulp Industries Co., Ltd. The content (mass%) of biomass raw material in the fibrous binder of Example 1 was 100%.

[0075] The nonwoven fabric used in Example 1 was a nonwoven fabric containing polyolefin resin fibers and biomass-derived cellulose fibers, Heat Pack MW / 50 g, manufactured by Nippon Paper Papylia Co., Ltd., as shown in #22 in Tables 5 and 6. The biomass raw material content (mass%) of the nonwoven fabric in Example 1 was 55%.

[0076] The adhesive used in Example 1 was a biomass-derived polyamide resin, TECHNOMELT PA6202, manufactured by Henkel Japan Ltd., which is listed as #5 in Tables 7 and 8. The content (mass %) of biomass raw materials in the adhesive of Example 1 was 50%.

[0077] The nonwoven fabric of Example 2 and the adhesive of Example 2 are the same as the nonwoven fabric of Example 1 and the adhesive of Example 1.

[0078] The cap of Example 2 was made of polyhydroxybutyrate / hydroxyhexanoate (PHBH) resin, microbial metabolites, and Green Planet M304 (manufactured by Kaneka Corporation) listed in #15 of Tables 1 and 2. The biomass raw material content (mass%) of the cap of Example 2 was 100%.

[0079] The fibrous binder used in Example 2 was the cellulose fiber listed in #3 of Tables 3 and 4, Celish PC110A manufactured by Daicel Corporation, and the cellulose fiber listed in #8, nano forest-S NS manufactured by Chuetsu Pulp Industries Co., Ltd. The content (mass%) of biomass raw material in the fibrous binder of Example 2 was 100%.

[0080] The cap of Example 3 is the same as the cap of Example 2. The nonwoven fabric of Example 3 is the same as the nonwoven fabric of Example 1.

[0081] The fibrous binder used in Example 3 was the cellulose fiber listed in #2 of Tables 3 and 4, Celish PC110T manufactured by Daicel Corporation, and the cellulose fiber listed in #5, nano forest-S BB-RB manufactured by Chuetsu Pulp Industries Co., Ltd. The content (mass%) of biomass raw material in the fibrous binder of Example 3 was 100%.

[0082] The adhesive of Example 3 used a biomass-derived rosin-based resin, Labelmelt (registered trademark) BL-8603KC, manufactured by Toyochem Co., Ltd., listed in #8 of Tables 7 and 8. The content (mass %) of biomass raw materials in the adhesive of Example 3 was 35% or more and 40% or less.

[0083] The cap of Example 4 is the same as the cap of Example 2. The nonwoven fabric of Example 3 is the same as the nonwoven fabric of Example 1.

[0084] The fibrous binder used in Example 4 was the cellulose fiber listed in #2 of Tables 3 and 4, Celish PC110T manufactured by Daicel Corporation, and the cellulose fiber listed in #7, nano forest-S BS manufactured by Chuetsu Pulp Industries Co., Ltd. The content (mass%) of biomass raw materials in the fibrous binder of Example 4 was 100%.

[0085] The adhesive of Example 4 used a biomass-derived rosin-based resin, Labelmelt (registered trademark) BL-8603C, manufactured by Toyochem Co., Ltd., listed in #9 in Tables 7 and 8. The content (mass %) of biomass raw materials in the adhesive of Example 4 was 35% or more and 40% or less.

[0086] The comparative cap used petroleum-derived polypropylene listed in #18 in Tables 1 and 2. The comparative fibrous binder used petroleum-derived acrylonitrile resin fiber listed in #1 in Tables 3 and 4. The comparative nonwoven fabric used petroleum-derived polyolefin resin fiber-containing nonwoven fabric listed in #1 in Tables 5 and 6. The comparative adhesive used petroleum-derived polypropylene listed in #1 in Tables 7 and 8.

[0087] First, the experimenter prepared a slurry of activated carbon, lead removal material, and fibrous binder in the mass proportions shown in Table 10. The activated carbon used was biomass-derived activated carbon, and the lead removal material used was mineral-derived lead removal material.

[0088] Next, the experimenter attached a ceramic core (outer diameter φ8 mm, inner diameter φ5 mm) to the molding machine and sucked it into the slurry to form a cylindrical molded adsorbent. The size of the molded adsorbent was set to an outer diameter of φ24.7 mm, an inner diameter of φ8 mm, and a height of 90 mm. The experimenter dried and polished the molded adsorbent, wrapped it in nonwoven fabric, and attached a cap to create a water purification filter.

[0089] The obtained water purification filters of Example 1 to Experimental Example 4 and Comparative Example were subjected to the tests described in Table 9. Filters that met the criteria described in Table 9 were evaluated as "good." The evaluation results are also shown in Table 9. The water purification filters of Example 1 to Experimental Example 4 were all evaluated as "good," ensuring their performance as water purification filters.

[0090] [Table 9]

[0091] The percentage of petroleum-derived raw materials used and the amount of CO2 increase (L) per kg of the water purification filter were calculated for the water purification filters of Examples 1 and 2 and the Comparative Example. The results are shown in Table 10.

[0092] [Table 10]

[0093] The usage rate of petroleum-derived raw materials was 1% to 2% in the water purification filters of Examples 1 to 4. In contrast, the usage rate of petroleum-derived raw materials in the water purification filter of the Comparative Example was 21%.

[0094] The increase in CO2 at the ground surface due to the CO2 released upon disposal of the water purification filters of Examples 1 to 4 was 20 L to 36 L per kilogram. In contrast, the increase in CO2 at the ground surface due to the CO2 released upon disposal of the water purification filter of the comparative example was 325 L per kilogram.

[0095] The water purification filter of the example was able to contribute to reducing the environmental load while ensuring the performance as a water purification filter. [Explanation of symbols]

[0096] 1...molded adsorbent, 3...activated carbon, 5...lead removal material, 7...fibrous binder, 11...water purification filter, 12...core material, 14...nonwoven fabric, 15...cap, 16...cap, 20...flow path, 60...exhaust port

Claims

1. CO released during disposal ２ CO2 on the Earth's surface due to ２ The increase is no more than 240 L per kilogram; and A water purification filter that meets at least one of the following criteria: The content of petroleum-derived raw materials is 15% or less.

2. a resin part containing resin, The water purification filter according to claim 1, wherein the resin is at least one selected from the group consisting of polyhydroxybutyrate / hydroxyhexanoate (PHBH) resin and biomass-derived polyolefin resin.

3. Equipped with nonwoven fabric, The water purification filter according to claim 1 or 2, wherein the nonwoven fabric contains one or more fibers selected from the group consisting of biomass-derived cellulose fibers and biomass-derived polyolefin resin fibers.

4. an adhesive layer made of an adhesive; The water purification filter according to claim 1 or 2, wherein the adhesive contains one or more selected from the group consisting of a biomass-derived polyamide resin, a biomass-derived rosin-based resin, and a biomass-derived polyolefin resin.

5. A hollow cylindrical core material; a cylindrical molded adsorbent body disposed on the outer periphery of the core material and containing plant-derived activated carbon and a plant-derived fibrous binder; a support disposed on the outer periphery of the molded adsorbent body; 2. The water purification filter according to claim 1, further comprising sealing caps that are in watertight contact with the bottom and top surfaces of the molded adsorbent body.

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