US 12,466,959 B2
Method for removing foreign material from carbonaceous material dispersion
Tomokiyo Takeyama, Tokyo (JP); Masaru Nakajo, Tokyo (JP); Kensuke Fukasawa, Tokyo (JP); and Takao Suzuki, Tokyo (JP)
Assigned to REFINE HOLDINGS CO., LTD., Gifu (JP)
Filed by REFINE HOLDINGS CO., LTD., Gifu (JP)
Filed on Sep. 9, 2021, as Appl. No. 17/470,417.
Claims priority of application No. 2020-152275 (JP), filed on Sep. 10, 2020.
Prior Publication US 2022/0073752 A1, Mar. 10, 2022
Int. Cl. C09C 1/56 (2006.01); B01D 29/56 (2006.01); B01D 29/88 (2006.01); B01D 35/06 (2006.01); B01D 37/00 (2006.01); B03C 1/30 (2006.01); C09C 1/48 (2006.01)
CPC C09C 1/56 (2013.01) [B01D 29/56 (2013.01); B01D 29/885 (2013.01); B01D 35/06 (2013.01); B01D 37/00 (2013.01); B03C 1/30 (2013.01); C09C 1/48 (2013.01); B01D 2257/60 (2013.01); B01D 2259/814 (2013.01); B03C 2201/18 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2006/80 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for removing foreign materials from a carbonaceous material dispersion in which carbonaceous material particles are dispersed in a dispersing medium, the method comprising:
(i) applying the dispersion to a primary filter a specified number of times in circulation, the primary filter comprising at least one filter device, comprising repeatedly applying the dispersion to the primary filter a number of times after it has been passed through the primary filter once, until the specified number of times is reached; and
(ii) applying the dispersion treated by the primary filter to a secondary filter a single time, the secondary filter comprising at least two filter devices arranged in series;
wherein each respective filter device satisfies the following conditions:
(a) a variation of a cumulative undersize distribution Q [%] with respect to a reference particle diameter, and a variation of non-volatile content, before and after being applied to each respective filter element, are not more than 0.1%, respectively; and
(b) a removal rate of particles with a threshold particle diameter being not less than 20%;
wherein the reference particle diameter is set as a particle diameter of the carbonaceous material particles having a cumulative frequency of 99.8% or more, and the threshold particle diameter is set as a value of at least 5 μm greater than the reference particle diameter; and
wherein the carbonaceous material is one or more selected from the group consisting of graphite, carbon black, carbon nanotubes, carbon nanofiber, carbon fiber, fullerene, and natural graphite.