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US-12623204-B2 - Adsorption filter

US12623204B2US 12623204 B2US12623204 B2US 12623204B2US-12623204-B2

Abstract

The adsorption filter according to the present invention is formed from a molded body including activated carbon and a binder, the pore volume of pores having a diameter of 10 μm or greater in terms of the volume of the adsorption filter as measured through mercury intrusion being 0.10 cm 3 /cc to 0.39 cm 3 /cc.

Inventors

  • Keita Takahashi
  • Tetsuya Hanamoto
  • Hiroe Yoshinobu

Assignees

  • KURARAY CO., LTD.

Dates

Publication Date
20260512
Application Date
20210921
Priority Date
20201001

Claims (20)

  1. 1 . An adsorption filter comprising a molded body containing activated carbon and a binder, wherein a pore volume of pores having a pore diameter of 10 μm or more on a volume basis of the adsorption filter is 0.10 cm 3 /cc to 0.39 cm 3 /cc, the pore volume being measured by mercury intrusion porosimetry, and wherein a total pore volume on a volume basis of the adsorption filter is 0.50 cm 3 /cc to 0.73 cm 3 /cc, the total pore volume being measured by mercury intrusion porosimetry.
  2. 2 . The adsorption filter according to claim 1 , wherein a density of the adsorption filter is 0.59 g/cm 3 or less.
  3. 3 . The adsorption filter according to claim 1 , wherein the pore volume of pores having a pore diameter of 10 μm or more on a volume basis of the adsorption filter is 0.15 cm 3 /cc to 0.35 cm 3 /cc and the total pore volume on a volume basis of the adsorption filter is 0.53 cm 3 /cc to 0.70 cm 3 /cc.
  4. 4 . The adsorption filter according to claim 1 , wherein a proportion of a pore volume of pores having a pore diameter of 10 μm or more on a volume basis of the adsorption filter in a total pore volume on a volume basis of the adsorption filter is 12% or more, the pore volume and the total pore volume being measured by mercury intrusion porosimetry.
  5. 5 . The adsorption filter according to claim 1 , wherein a pore volume of pores having a pore diameter of 7 μm or less on a volume basis of the adsorption filter is 0.15 cm 3 /cc or more, the pore volume being measured by mercury intrusion porosimetry.
  6. 6 . The adsorption filter according to claim 1 , wherein a proportion of a pore volume of pores having a pore diameter of 7 μm or less on a volume basis of the adsorption filter in a total pore volume on a volume basis of the adsorption filter is 22% or more, the pore volume and the total pore volume being measured by mercury intrusion porosimetry.
  7. 7 . An adsorption filter comprising a molded body containing activated carbon and a binder, wherein a pore volume of pores having a pore diameter of 7 μm or less on a volume basis of the adsorption filter is 0.15 cm 3 /cc or more, the pore volume being measured by mercury intrusion porosimetry; and a total pore volume on a volume basis of the adsorption filter is 0.50 cm 3 /cc to 0.73 cm 3 /cc, the total pore volume being measured by mercury intrusion porosimetry.
  8. 8 . The adsorption filter according to claim 7 , wherein a proportion of a pore volume of pores having a pore diameter of 7 μm or less on a volume basis of the adsorption filter in a total pore volume on a volume basis of the adsorption filter is 22% or more, the pore volume and the total pore volume being measured by mercury intrusion porosimetry.
  9. 9 . The adsorption filter according to claim 1 , wherein a pore mode diameter measured by mercury intrusion porosimetry is 15 μm or less.
  10. 10 . The adsorption filter according to claim 1 , wherein in a carbide obtained by heat-treating the adsorption filter at 900° C. for 20 minutes in an inert gas, a content of particles having a particle size of 10 μm or less is 2 vol % or more.
  11. 11 . The adsorption filter according to claim 1 , wherein a benzene saturated adsorption amount determined from an increase in an amount of a sample when air containing solvent vapor having a solvent saturated concentration of 1/10 is passed through the sample at 25° C. and a mass of the sample becomes constant is 18% to 35%.
  12. 12 . The adsorption filter according to claim 1 , wherein in a carbide obtained by heat-treating the adsorption filter at 900° C. for 20 minutes in an inert gas, a 0% particle size in volume-based cumulative particle size distribution is 7 μm or less.
  13. 13 . The adsorption filter according to claim 1 , wherein the binder contains a fibrous binder.
  14. 14 . The adsorption filter according to claim 13 , wherein the fibrous binder contains an acrylic fibrous binder.
  15. 15 . The adsorption filter according to claim 13 , wherein the fibrous binder contains a cellulose fibrous binder.
  16. 16 . The adsorption filter according to claim 7 , wherein a pore mode diameter measured by mercury intrusion porosimetry is 15 μm or less.
  17. 17 . The adsorption filter according to claim 7 , wherein in a carbide obtained by heat-treating the adsorption filter at 900° C. for 20 minutes in an inert gas, a content of particles having a particle size of 10 μm or less is 2 vol % or more.
  18. 18 . The adsorption filter according to claim 7 , wherein a benzene saturated adsorption amount determined from an increase in an amount of a sample when air containing solvent vapor having a solvent saturated concentration of 1/10 is passed through the sample at 25° C. and a mass of the sample becomes constant is 18% to 35%.
  19. 19 . The adsorption filter according to claim 7 , wherein in a carbide obtained by heat-treating the adsorption filter at 900° C. for 20 minutes in an inert gas, a 0% particle size in volume-based cumulative particle size distribution is 7 μm or less.
  20. 20 . The adsorption filter according to claim 1 , wherein the total pore volume on a volume basis of the adsorption filter is 0.56 cm 3 /cc to 0.67 cm 3 /cc.

Description

TECHNICAL FIELD The present invention relates to an adsorption filter including a molded body containing activated carbon and a binder. BACKGROUND ART In recent years, there has been an increasing concern about safety and health related to water quality of tap water, and it is desired to remove harmful substances such as free residual chlorine, volatile organic compounds (VOCs) such as trihalomethanes, agricultural chemicals, and mold odor contained in tap water. In order to remove such harmful substances, an adsorption filter including an activated carbon molded body is generally used. The adsorption filter including an activated carbon molded body is also desired to have performance of removing turbid components (particulate substances) contained in tap water. Therefore, for example, Patent Literature 1 discloses a method for producing a turbidity reduction filter body that can be used for a longer period of time by adjusting a difference in hardness between an inflow filter medium portion and an outflow filter medium portion of an activated carbon molded body. Further, for example, Patent Literature 2 discloses a water purification cartridge including an activated carbon molded body and a nonwoven fabric, the water purification cartridge being capable of achieving both high turbidity removal performance and a sufficiently long clogging prevention life. Further, for example, Patent Literature 3 discloses an activated carbon molded body obtained by molding a mixture containing a powdered activated carbon (a) having a center particle size of 80 μm to 120 μm and a standard deviation σg in particle size distribution of 1.3 to 1.9, and a fibrous binder (b). Patent Literature 3 states that the activated carbon molded body is excellent in the ability to remove free residual chlorine, volatile organic compounds, CAT, and 2-MIB, and is also excellent in the ability to filtrate turbidity. CITATION LIST Patent Literatures Patent Literature 1: JP 2015-033680 APatent Literature 2: JP 2016-140788 APatent Literature 3: WO 2011/016548 A SUMMARY OF INVENTION An object of the present invention is to provide an adsorption filter having excellent ultrafine particle removal performance while maintaining good water permeability. As a result of intensive studies to solve the above problems, the present inventors have reached the present invention. An adsorption filter according to an aspect of the present invention is an adsorption filter comprising a molded body containing activated carbon and a binder, wherein a pore volume of pores having a pore diameter of 10 μm or more on a volume basis of the adsorption filter is 0.10 cm3/cc to 0.39 cm3/cc, the pore volume being measured by mercury intrusion porosimetry. Alternatively, an adsorption filter according to another aspect of the present invention is an adsorption filter comprising a molded body containing activated carbon and a binder, wherein a pore volume of pores having a pore diameter of 7 μm or less on a volume basis of the adsorption filter is 0.15 cm3/cc or more, the pore volume being measured by mercury intrusion porosimetry; anda total pore volume on a volume basis of the adsorption filter is 0.50 cm3/cc to 0.73 cm3/cc, the total pore volume being measured by mercury intrusion porosimetry. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view showing an example of a mold for preparing an adsorption filter in the present embodiment. FIG. 2 is a perspective view showing an example of an adsorption filter obtained using the mold of FIG. 1 in the present embodiment. FIG. 3 is a view for describing how to cut out a sample when the pore volume and the pore mode diameter of an adsorption filter are measured. FIG. 4 is a view for describing how to cut out a measurement sample when the particle size distribution of activated carbon (carbide after heat treatment) in an adsorption filter is measured. FIG. 5 is a perspective view showing an example of an automatic grinder for producing an adsorption filter. FIG. 6 is a graph showing the pore mode diameter of an adsorption filter and a section pore volume thereof. FIG. 7 is a graph showing a correlation between the pore volume of pores having a pore diameter of 10 μm or more and ultrafine particle removal performance of an adsorption filter. FIG. 8 is a graph showing a correlation between the pore volume of pores having a pore diameter of 7 μm or less and ultrafine particle removal performance of an adsorption filter. DESCRIPTION OF EMBODIMENTS In the activated carbon molded bodies of Patent Literatures 1, 2, and 3 described above, turbidity removal performance is evaluated. A turbidity removal performance test performed on a filter of an activated carbon molded body is generally specified in, for example, JIS S 3201: 2019. In this test, about 1 μm to 20 μm of kaolin is used as a turbidity component (particulate substance), and the removal performance thereof is evaluated. In the evaluations of the activated carbon molded bod