IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
UP-0848970
(2004-05-19)
|
등록번호 |
US-7515397
(2009-07-01)
|
발명자
/ 주소 |
- Reed, David M.
- Venigalla, Sridhar
- Kitchell, Ricky W.
- Krause, Stephen J.
- Enman, Heather L.
- Schultz, Dorran L.
- Kerchner, Jeffrey A.
|
출원인 / 주소 |
|
인용정보 |
피인용 횟수 :
2 인용 특허 :
45 |
초록
▼
Methods to at least partially reduce a niobium oxide are described wherein the process includes mixing the niobium oxide and niobium powder to form a powder mixture that is then heat treated to form heat treated particles which then undergo reacting in an atmosphere which permits the transfer of oxy
Methods to at least partially reduce a niobium oxide are described wherein the process includes mixing the niobium oxide and niobium powder to form a powder mixture that is then heat treated to form heat treated particles which then undergo reacting in an atmosphere which permits the transfer of oxygen atoms from the niobium oxide to the niobium powder, and at a temperature and for a time sufficient to form an oxygen reduced niobium oxide. Oxygen reduced niobium oxides having high porosity are also described as well as capacitors containing anodes made from the oxygen reduced niobium oxides.
대표청구항
▼
What is claimed is: 1. Oxygen reduced niobium oxide granules, wherein the oxygen reduced niobium oxide granules have a multi-modal pore size distribution of from about 0.1 to about 20 microns, after being pressed and sintered, and are formed from oxygen reduced niobium oxide having a BET surface ar
What is claimed is: 1. Oxygen reduced niobium oxide granules, wherein the oxygen reduced niobium oxide granules have a multi-modal pore size distribution of from about 0.1 to about 20 microns, after being pressed and sintered, and are formed from oxygen reduced niobium oxide having a BET surface area of from about 0.5 to about 8 m2/g. 2. The oxygen reduced niobium oxide granules of claim 1, wherein said oxygen reduced niobium oxide has a BET surface area of from about 1 to about 8 m2/g. 3. The oxygen reduced niobium oxide granules of claim 1, wherein said oxygen reduced niobium oxide has a capacitance, when formed into an electrolytic capacitor anode at a Vf of 30 V and sintered at 1380° C. for 10 minutes, of from about 40,000 to about 300,000 CV/g, and a DC leakage of less than about 0.5 nA/CV. 4. The oxygen reduced niobium oxide granules of claim 1, wherein said oxygen reduced niobium oxide has a flow of at least about 300 mg/s. 5. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a D50 size of from about 30 to about 1,000 microns. 6. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a primary particle size of from about 0.1 to about 5 microns. 7. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a pore volume of from about 0.1 to about 0.25 mL/g, after being pressed and sintered. 8. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a diametric shrinkage of from about 0.1 to about 10%, after being pressed at 2.8 g/cc and sintered at 1380 C for 10 mins. 9. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a pressability of from about 2.4 to about 3.5 g/cc. 10. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have a combined amount of Fe/Ni/Cr of less than about 100 ppm. 11. A capacitor anode comprising the granules of claim 1. 12. The capacitor anode of claim 11, wherein said capacitor anode has a capacitance of from about 40,000 to about 300,000 CV/g when formed at a Vf of 30 V and sintered at 1380° C. for 10 minutes. 13. The capacitor anode of claim 11, wherein said capacitor anode has a DC leakage of less than about 0.5 nA/CV. 14. The oxygen reduced niobium oxide granules of claim 1, further having a sintered crush strength of at least 35 lbs. 15. The oxygen reduced niobium oxide granules of claim 14, wherein said sintered crush strength is from about 35 lbs. to about 75 lbs. 16. The oxygen reduced niobium oxide granules of claim 1, further having a granule strength substantially independent of granule size. 17. The oxygen reduced niobium oxide granules of claim 16, wherein said granule strength is substantially independent of granule size wherein said granule size is from about 75 microns to about 425 microns. 18. The oxygen reduced niobium oxide granules of claim 16, wherein said valve metal sub-oxide powder further has a green crush strength of at least 1 lb. 19. The oxygen reduced niobium oxide granules of claim 1, further having a granule strength, measured by a D50(NU)/D50(120S-U) ratio, of from about 1.0 to about 3.5. 20. The oxygen reduced niobium oxide granules of claim 19, wherein said ratio is from about 1 to about 3. 21. The oxygen reduced niobium oxide granules of claim 1, further having a pore size distribution having an adjustable log differential intrusion peak height of from about 0.4 mL/g to about 0.75 mL/g. 22. The oxygen reduced niobium oxide granules of claim 1, further having a carbon retention after delube of less than 200 ppm. 23. The oxygen reduced niobium oxide granules of claim 1, wherein said granules have an oxygen content of from about 5,000 to about 15,000 ppm and a mean particle size of from about 3 to about 4 microns when said granules have a BET surface area of from about 1 to about 2 m2/g, an oxygen content of from about 15,000 to about 22,000 ppm and a mean particle size of from about 2 to about 3 microns when said granules have a BET surface area of from about 2 to about 3 m2/g, an oxygen content of from about 22,000 to about 28,000 ppm and a mean particle size of from about 1 to about 2 microns when said granules have a BET surface area of from about 3 to about 4.5 m2/g, and an oxygen content of at least about 28,000 ppm and a mean particle size of less than about 1 micron when said granules have a BET surface area of at least about 4.5 m2/g, and an oxygen content of from about 28,000 to about 70,000 ppm and a mean particle size of less than 1 micron when said granules have a BET surface area of from about 5 to about 8 microns. 24. The oxygen reduced niobium oxide granules of claim 23, wherein said granules have a flow of at least about 300 mg/s. 25. The oxygen reduced niobium oxide granules of claim 23, wherein said granules after being pressed and sintered have a diametric shrinkage of from about 1 to about 12%. 26. The oxygen reduced niobium oxide granules of claim 23, wherein said granules have a capacitance of from about 35,000 to about 300,000 CV/g and a leakage current of from about 0.2 to about 2 nA/CV when said granules are sintered at a temperature of 1125° C. for 10 minutes at a Vf of 40 V. 27. The oxygen reduced niobium oxide of claim 1, wherein the granules have a multimodal pore size distribution from about 0.1 to about 10 microns, after being pressed and sintered. 28. A method of making the oxygen reduced niobium oxide granules of claim 1, comprising: providing oxygen reduced niobium oxide having a BET surface area of from about 0.5 to about 8 m2/g; and heat treating said oxygen reduced niobium oxide under vacuum or inert gases to form heat-treated oxygen reduced niobium oxide granules having a BET surface area that is less than the BET surface area of said provided oxygen reduced niobium oxide. 29. The method of claim 28, wherein said heat-treated oxygen reduced niobium oxide has a crush strength of at least about 90% of a crush strength of said oxygen reduced valve metal oxide. 30. A method to at least partially reduce a niobium oxide, comprising: mixing a niobium powder and a starting niobium oxide together to form a powder mixture and granulating said powder mixture to form granules; heat treating said granules under vacuum or inert gases to form heat treated granules; and reacting said heat treated granules in an atmosphere which permits the transfer of oxygen atoms from said starting niobium oxide to said niobium powder, wherein said reacting occurs for a time and at a temperature sufficient to form an oxygen reduced niobium oxide. 31. The method of claim 30, wherein said niobium powder has a BET surface area of from about 1 to about 8 m2/g. 32. The method of claim 30, wherein said starting niobium oxide has a BET surface area of from about 1 to about 15 m2/g. 33. The method of claim 30, wherein said oxygen reduced niobium oxide is NbO. 34. The method of claim 30, wherein said oxygen reduced niobium oxide has an atomic ratio of niobium to oxygen of 1:less than 2.5. 35. The method of claim 30, wherein said temperature of said reacting is about 850° C., and said time of said reacting is from about 1 hour. 36. The method of claim 30, wherein said atmosphere is hydrogen and is present in an amount of 10 to about 1,000 Torr. 37. The method of claim 30, wherein said granulating forms granules having a size of less than 425 microns. 38. The method of claim 30, wherein said mixing comprises co-milling said niobium powder with said starting niobium oxide. 39. The method of claim 30, wherein said mixing comprises co-milling said niobium powder with said starting niobium oxide such that any aggregates present in said niobium powder and/or in said starting niobium oxide are reduced to their respective primary particles. 40. The method of claim 30, further comprising post heat treating said oxygen reduced niobium oxide at a temperature and for a time sufficient to reduce the BET surface area of the oxygen reduced niobium oxide by at least 1% and to reduce the capacitance capability of said oxygen reduced niobium oxide by no more than 25%. 41. The method of claim 30, further comprising post heat treating said oxygen reduced niobium oxide at a temperature of from about 800° C. to about 1300° C., wherein said post heat treatment reduces the capacitance capability of said oxygen reduced niobium oxide by no more than 25%. 42. The method of claim 41, wherein said post heat treatment reduces the capacitance capability of said oxygen reduced niobium oxide by no more than 10%. 43. The method of claim 30, wherein said granulating comprises wet screening. 44. The method of claim 30, wherein said granulating comprises wet granulating. 45. The method of claim 30, wherein said granulating comprises dry granulating. 46. The method of claim 30, wherein said granulating of said oxygen reduced niobium oxide forms granules having a size of from about 30 to about 1,000 microns. 47. Oxygen reduced niobium oxide granules having a pore size distribution with a mono-modal log differential intrusion peak at 0.4 micron, and said peak has a breadth of from 0.2 to 0.6 microns at 0.1 mL/g, and said peak has a height greater than 0.5 mL/g, when pressed and sintered. 48. Oxygen reduced niobium oxide granules having a pore size distribution with a mono-modal log differential intrusion peak located at 0.5 to 0.8 microns, wherein said peak has a breadth of from 0.3 to 1.1 microns at 0.1 mL/g, and said peak has a height greater than 0.6 mL/g, when pressed and sintered. 49. Oxygen reduced niobium oxide granules having a pore size distribution such that a mono-modal log differential intrusion peak is present with a shoulder extending from 0.3 micron or less to 10 microns or greater with a shoulder height of less than 0.1 mL/g, when pressed and sintered. 50. Oxygen reduced niobium oxide granules having a pore size distribution which includes a shoulder that has a ratio of cumulative volume between 1 and 10 microns, wherein said ratio is from 1 to 7.5, when pressed and sintered. 51. Oxygen reduced niobium oxide granules having a pore size distribution which includes a shoulder that has a total porosity from 4 to 13 percent above 1 micron, when pressed and sintered. 52. Oxygen reduced niobium oxide granules having a pore size distribution which includes a shoulder that has a total porosity of from 1 to 4 percent and pore sizes of less than 10 microns, when pressed and sintered. 53. A method to at least partially reduce a valve metal oxide, comprising: subjecting a starting valve metal oxide to a first heat treatment in the presence of a getter material and in an atmosphere which permits the transfer of oxygen atoms from said starting valve metal oxide to said getter material, to form an oxygen reduced valve metal oxide having a first BET surface area; and subjecting said oxygen reduced valve metal oxide to a second heat treatment under vacuum or inert gases to form a heat-treated oxygen reduced valve metal oxide having a second BET surface area, wherein said second BET surface area is less than said first BET surface area. 54. The method of claim 53, wherein said heat-treated oxygen reduced valve metal oxide has a crush strength of at least about 90% of a crush strength of said oxygen reduced valve metal oxide. 55. The heat-treated oxygen reduced valve metal oxide formed by the method of claim 53. 56. A capacitor comprising the heat-treated oxygen reduced valve metal oxide of claim 55. 57. Niobium sub-oxide granules having at least a)through c) and at least one of d) through h) of the following characteristics: a) BET surface area of powder ("BET"): about 1.4 to about 2.5 m2/g b) Scott Density of powder ("Scott"): about 19 to about 28 g/in3 c) capacitance @ 10 Vb ("CV/g"): 69,000-83,000 μFV/g d) CV/g×BET×Scott: 1.12×1011-3.55×1011 CV/(m*g) e) CV/g×1/BET×Scott: 3.2×1010-10.1×1010 (CV*g)/m5 f) CV/g×1/BET×1/Scott: 1.62×10-2-5.11×10-2 (CV*m/g) g) CV/g×1/BET: 33,000-57,000 CV/m2 h) CV/g×Scott: 1.10×106-2.20×106 CV/in3. 58. The niobium sub-oxide granules of claim 57, wherein said niobium sub-oxide powder has at least characteristics d) and g). 59. The niobium sub-oxide granules of claim 57, wherein said niobium sub-oxide powder has characteristics e), f), g), and h). 60. The niobium sub-oxide granules of claim 57, wherein said niobium sub-oxide powder is NbO.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.