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CN-122003285-A - Method of forming a monolithic article

CN122003285ACN 122003285 ACN122003285 ACN 122003285ACN-122003285-A

Abstract

A method of forming a monolithic article includes extruding an extrudable composition to form an extrudate including a binder, inorganic particles, and graphite particles, the extrudate including an outer skin and a core disposed within the outer skin, drying the extrudate, degreasing the extrudate in a degreasing atmosphere at one or more degreasing temperatures to remove the binder from the extrudate, and sintering the extrudate in a sintering atmosphere at one or more sintering temperatures to remove the graphite particles from the outer skin of the extrudate and sinter the inorganic particles of the extrudate, thereby forming the monolithic article. The one or more degreasing temperatures are less than 650 ℃. The one or more sintering temperatures are greater than or equal to 650 ℃ and the oxygen concentration of the sintering atmosphere is less than or equal to 2.5%.

Inventors

  • D.M. BILL
  • D.A. Kennedy

Assignees

  • 康宁股份有限公司

Dates

Publication Date
20260508
Application Date
20241121
Priority Date
20231130

Claims (20)

  1. 1. A method of forming a unitary article, the method comprising: Extruding an extrudable composition comprising a binder, inorganic particles, and graphite particles to form an extrudate comprising an outer skin and a core disposed within the outer skin; Drying the extrudate; Degreasing the extrudate in a degreasing atmosphere at one or more degreasing temperatures to remove the binder from the extrudate, wherein the one or more degreasing temperatures are less than 650 ℃, and Sintering the extrudate in a sintering atmosphere at one or more sintering temperatures to remove the graphite particles from the outer skin of the extrudate and sinter the inorganic particles of the extrudate to form the monolithic article, wherein the one or more sintering temperatures is greater than or equal to 650 ℃ and the sintering atmosphere has an oxygen concentration of less than or equal to 2.5%.
  2. 2. The method of claim 1, wherein the sintering atmosphere has an oxygen concentration greater than or equal to 0.0% and less than or equal to 2.5%.
  3. 3. The method of claim 1 or claim 2, wherein the one or more degreasing temperatures are greater than or equal to 200 ℃ and less than 650 ℃.
  4. 4. The method of any one of claims 1-3, wherein the degreasing comprises maintaining the extrudate at a degreasing temperature and in the degreasing atmosphere for greater than or equal to 2 hours and less than or equal to 40 hours.
  5. 5. The method of claim 4, wherein the degreasing comprises increasing in the degreasing atmosphere to one of the one or more degreasing temperatures at a first ramp rate greater than or equal to 5 ℃ per hour and less than or equal to 20 ℃ per hour.
  6. 6. The method of any one of claims 1 to 5, wherein the degreasing atmosphere has an oxygen concentration of greater than or equal to 3% and less than or equal to 18%.
  7. 7. The method of any one of claims 1 to 6, wherein the one or more sintering temperatures are greater than or equal to 650 ℃ and less than or equal to 1000 ℃.
  8. 8. The method of any one of claims 1-7, wherein the sintering comprises maintaining the extrudate at a sintering temperature and in the sintering atmosphere for greater than or equal to 0.5 hours to less than or equal to 8 hours.
  9. 9. The method of claim 8, wherein the sintering comprises increasing to the holding sintering temperature at a second ramp rate greater than or equal to 5 ℃ per hour and less than or equal to 100 ℃ per hour.
  10. 10. The method of any one of claims 1-9, wherein at least one of the degreasing atmosphere and the sintering atmosphere comprises nitrogen, argon, or a combination thereof.
  11. 11. The method of any one of claims 1 to 10, wherein the binder comprises an organic binder comprising cellulose, cellulose derivatives, polymers, thermosetting resins, or combinations thereof.
  12. 12. The method of any one of claims 1 to 11, wherein the inorganic particles comprise borates, phosphates, transition metal oxides, hydroxides, carbonates, silicates, aluminosilicates, or combinations thereof.
  13. 13. The method of claim 12, wherein the inorganic particles comprise talc, clay, mgO, alumina, or a combination thereof.
  14. 14. The method of any one of claims 1 to 13, wherein the graphite particles comprise graphite sheets, graphite flakes, natural graphite, synthetic graphite, or a combination thereof.
  15. 15. The method of any one of claims 1 to 14, wherein the extrudable composition further comprises a pore forming material comprising starch, nut shell powder, carbon, natural polymer, synthetic polymer, carbonaceous material, crystalline carbon, amorphous carbon, or a combination thereof.
  16. 16. The method of any one of claims 1 to 15, wherein the extrudable composition further comprises a porous material comprising paper, polymer, glass-ceramic, diatomaceous earth, perlite, pumice, or a combination thereof.
  17. 17. The method of claim 16, wherein the porous material comprises hollow glass beads.
  18. 18. The method of any one of claims 1 to 17, wherein the core has the shape of a honeycomb structure comprising a plurality of cells therein defining parallel channels longitudinally through the honeycomb structure.
  19. 19. A unitary article comprising: An outer skin comprising an inorganic material, and A core disposed within the outer skin, the core comprising a continuous graphite phase and an inorganic phase comprising the inorganic material, wherein the graphite phase and the inorganic phase together form an interconnected pore structure, wherein: the modulus of rupture of the outer skin is at least 150% greater than the modulus of rupture of the core, as measured according to ASTM-D6272, and The monolithic article is electrically conductive.
  20. 20. The unitary article of claim 19, wherein the outer skin is free or substantially free of graphite.

Description

Method of forming a monolithic article Cross Reference to Related Applications The present application claims priority from U.S. c. ≡119 to U.S. provisional application serial No. 63/604,317 filed on 11/30 of 2023, the contents of which are hereby incorporated by reference in their entirety. Technical Field The present description relates generally to monolithic articles, and in particular to methods of forming monolithic articles with improved mechanical strength. Background A method of removing CO 2 from a point source or ambient air includes flowing a stream containing CO 2 through a monolith containing an adsorbent that adsorbs CO 2. Subsequently, the CO 2 may be desorbed to remove it (e.g., by heating the monolith). One convenient way to heat the monolith is by resistive heating. However, conventional manufacturing processes for forming monolithic articles may not be cost effective and/or have limited scalability. Thus, there is a continuing need for a cost-effective and scalable method of forming monolithic articles with improved mechanical strength. Disclosure of Invention According to a first aspect A1, a method of forming a monolithic article may include extruding an extrudable composition to form an extrudate comprising a binder, inorganic particles, and graphite particles, the extrudate comprising an outer skin and a core disposed within the outer skin, drying the extrudate, degreasing the extrudate in a degreasing atmosphere at one or more degreasing temperatures to remove the binder from the extrudate, wherein the one or more degreasing temperatures are less than 650 ℃, and sintering the extrudate in a sintering atmosphere at one or more sintering temperatures to remove the graphite particles from the outer skin of the extrudate and sinter the inorganic particles of the extrudate, thereby forming the monolithic article, wherein the one or more sintering temperatures are greater than or equal to 650 ℃ and the sintering atmosphere has an oxygen concentration of less than or equal to 2.5%. A second aspect A2 includes the method of the first aspect A1, the sintering atmosphere having an oxygen concentration greater than or equal to 0.0% and less than or equal to 2.5%. The third aspect A3 includes the method of the first aspect A1 or the second aspect A2, wherein the one or more degreasing temperatures are greater than or equal to 200 ℃ and less than 650 ℃. The fourth aspect A4 includes the method of any one of the first to third aspects A1-A3, wherein the degreasing includes maintaining the extrudate at a degreasing temperature and in the degreasing atmosphere for greater than or equal to 2 hours and less than or equal to 40 hours. A fifth aspect A5 includes the method of the fourth aspect A4, wherein the degreasing comprises increasing in the degreasing atmosphere to one of the one or more degreasing temperatures at a first ramp rate of greater than or equal to 5 ℃ per hour and less than or equal to 20 ℃ per hour. A sixth aspect A6 includes the method of any one of the first to fifth aspects A1-A5, wherein the degreasing atmosphere has an oxygen concentration of greater than or equal to 3% and less than or equal to 18%. A seventh aspect A7 includes the method of any one of the first to sixth aspects A1-A6, wherein the one or more sintering temperatures are greater than or equal to 650 ℃ and less than or equal to 1000 ℃. An eighth aspect A8 includes the method of any one of the first to seventh aspects A1-A7, wherein the sintering comprises maintaining the extrudate at a sintering temperature and in the sintering atmosphere for greater than or equal to 0.5 hours to less than or equal to 8 hours. The ninth aspect A9 includes the method of the eighth aspect A8, wherein the sintering comprises increasing to the holding sintering temperature at a second ramp rate greater than or equal to 5 ℃ per hour and less than or equal to 100 ℃ per hour. The tenth aspect a10 includes the method of any one of the first to ninth aspects A1-A9, wherein at least one of the degreasing atmosphere and the sintering atmosphere comprises nitrogen, argon, or a combination thereof. The eleventh aspect a11 comprises the method of any one of the first to tenth aspects A1-a10, wherein the binder comprises an organic binder comprising cellulose, cellulose derivatives, polymers, thermosetting resins, or combinations thereof. The twelfth aspect a12 includes the method of any one of the first to eleventh aspects A1-a11, wherein the inorganic particles comprise borates, phosphates, transition metal oxides, hydroxides, carbonates, silicates, aluminosilicates, or combinations thereof. The thirteenth aspect a13 includes the method of the twelfth aspect a12, wherein the inorganic particles comprise talc, clay, mgO, alumina, or a combination thereof. A fourteenth aspect a14 includes the method of any one of the first to thirteenth aspects A1-a13, wherein the graphite particles comprise graphite sheets, natural graphite, synthetic graphite