High purity fine metal powders and methods to produce such powder

• US 6,786,950 B2
• Filed: 12/10/2002
• Issued: 09/07/2004
• Est. Priority Date: 02/15/2000
• Status: Expired due to Term

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: NanoProducts Corporation (Nouryon BV)
• Inventors: Yadav, Tapesh, Dirstine, Roger, Pfaffenbach, Karl
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US10/315,271
• Publication Number:
  US 20030126948A1
• Time in Patent Office: 637 Days
• Field of Search: 753/46, 75/101.9
• US Class Current: 75/346
• CPC Class Codes: B01J 19/088 giving rise to electric discharges for heating purposes H05B7/00; for the production of ozone C01B13/11, H01T19/00
• CPC Class Codes: B01J 2219/0886 Gas-solid
• CPC Class Codes: B01J 2219/0894 Processes carried out in the presence of a plasma
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/12 starting from gaseous material
• CPC Class Codes: B22F 9/14 using electric discharge
• CPC Class Codes: B22F 9/30 with decomposition of metal compounds, e.g. by pyrolysis
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 13/14 Methods for preparing oxides or hydroxides in general particular individual oxides or hydroxides, see the relevant groups of subclasses C01B - C01G or C25B, according to the element combined with the oxygen or hydroxy group
• CPC Class Codes: C01B 13/20 by oxidation of elements in the gaseous state; by oxidation or hydrolysis of compounds in the gaseous state
• CPC Class Codes: C01B 21/06 Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boronazides C01B21/08
• CPC Class Codes: C01B 21/0828 Carbonitrides or oxycarbonitrides of metals, boron or silicon
• CPC Class Codes: C01B 32/956 Silicon carbide
• CPC Class Codes: C01B 32/977 Preparation from organic compounds containing silicon
• CPC Class Codes: C01F 17/218 Yttrium oxides or hydroxides
• CPC Class Codes: C01F 17/235 Cerium oxides or hydroxides
• CPC Class Codes: C01F 5/06 by thermal decomposition of magnesium compounds calcining magnesite or dolomite C04B2/10
• CPC Class Codes: C01G 1/02 Oxides
• CPC Class Codes: C01G 19/00 Compounds of tin
• CPC Class Codes: C01G 25/00 : Compounds of zirconium
• CPC Class Codes: C01G 49/04 : Ferrous oxide [FeO]
• CPC Class Codes: C01G 49/06 : Ferric oxide [Fe2O3]
• CPC Class Codes: C01G 49/08 : Ferroso-ferric oxide [Fe3O4]
• CPC Class Codes: C01G 53/04 : Oxides; Hydroxides
• CPC Class Codes: C01P 2002/34 : perovskite-type (ABO3)
• CPC Class Codes: C01P 2002/52 : containing elements as dopants
• CPC Class Codes: C01P 2004/54 : Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
• CPC Class Codes: C01P 2004/61 : Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 : Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 : Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/12 : Surface area
• CPC Class Codes: C01P 2006/80 : Compositional purity
• CPC Class Codes: C04B 2235/3205 : Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
• CPC Class Codes: C04B 2235/3206 : Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 : Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3215 : Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3224 : Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 : Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 : Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3236 : Alkaline earth titanates
• CPC Class Codes: C04B 2235/3249 : containing also titanium oxide or titanates, e.g. lead zirconate titanate (PZT)
• CPC Class Codes: C04B 2235/3272 : Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
• CPC Class Codes: C04B 2235/3282 : Cuprates
• CPC Class Codes: C04B 2235/3286 : Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3293 : Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3427 : Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/3804 : Borides
• CPC Class Codes: C04B 2235/3817 : Carbides
• CPC Class Codes: C04B 2235/3826 : Silicon carbides
• CPC Class Codes: C04B 2235/3852 : Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3895 : Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/449 : Organic acids, e.g. EDTA, citrate, acetate, oxalate
• CPC Class Codes: C04B 2235/5409 : expressed by specific surface values
• CPC Class Codes: C04B 2235/5445 : submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/5454 : nanometer sized, i.e. below 100 nm
• CPC Class Codes: C04B 2235/72 : Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/721 : Carbon content
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: C04B 41/89 : for obtaining at least two superposed coatings having different compositions

Abstract

Methods of producing metal and alloy fine powders having purity in excess of 99.9%, preferably 99.999%, more preferably 99.99999% are discussed. Fine submicron and nanoscale powders discussed include various shapes and forms including spheres, rods, whiskers, platelets and fibers. The use of surfactant, emulsifying agents and capping dispersants in powder synthesis are presented. Compositions taught include nickel, copper, iron, cobalt, silver, gold, platinum, palladium, tin, zirconium, aluminum, silicon, antimony, indium, titanium, tantalum, niobium, zinc and others from the periodic table. The fine powders are useful in various applications such as biomedical, sensor, electronic, electrical, photonic, thermal, piezo, magnetic, catalytic and electrochemical products.

Claims

1. A process for producing fine metal powder comprising:

providing a feed composition wherein the feed composition comprises a fluid precursor with purity of at least 99.9% by metal basis;

transporting the fluid precursor to a reactor;

processing the fluid precursor in the reactor at a temperature greater than 2000°

C. in a gas comprising oxygen; and

transforming the precursor to fine metal powder with purity of at least 99.9% by metal basis.

2. The process of claim 1, where the temperature is greater than 3000°

C.

3. The process of claim 1, wherein the fine metal powder comprises a submicron powder.

4. The process of claim 1, wherein the fine metal powder comprises a nanoscale powder.

5. The process of claim 1, wherein the step of providing a feed composition comprises processing a fluid precursor through one or more steps selected from the group consisting of distillation, membranes, electrochemical cells, ion exchange and chromatography.

6. The process of claim 1, wherein the purity of the fine metal powder is greater than 99.99% on metal basis.

7. The process of claim 1, wherein the fine metal powder comprises a multimetal composition.

8. The process of claim 1, wherein the fine metal powder comprises nickel.

9. The process of claim 1, wherein the fine metal powder comprises a metal from the group consisting of:

aluminum, silicon, titanium, and zirconium.

10. The process of claim 1, wherein the fine metal powder comprises a metal from the group consisting of:

iron and copper.

11. A process for producing fine metal powder comprising:

providing a feed precursor with purity of at least 99.9% by metal basis;

transporting the feed precursor to a plasma reactor;

processing the feed precursor at a temperature greater than 2000°

C. in the plasma reactor in a gas comprising oxygen; and

transforming the feed precursor to fine metal powder with purity of at least 99.9% by metal basis.

12. The process of claim 11, where the temperature is greater than 3000°

C.

13. The process of claim 11, wherein the fine metal powder comprises a submicron powder.

14. The process of claim 11, wherein the fine metal powder comprises a nanoscale powder.

15. The process of claim 11, wherein the feed precursor comprises a fluid.

16. The process of claim 11, wherein the purity of the fine metal powder is greater than 99.99% on metal basis.

26. The process of claim 12, wherein the fine metal powder has an aspect ratio between 1 and 1,000,000.

17. A process for producing fine metal powder comprising:

providing a feed composition comprising a metal-containing organic substance with purity of at least 99.9% by metal basis;

atomizing the feed composition; and

heating the atomized feed composition thereby forming the fine metal powder with purity of at least 99.9% by metal basis.

18. The process of claim 17, wherein an emulsifying agent is added to the feed composition prior to the step of atomizing.

19. The process of claim 17, wherein the fine metal powder has a purity greater than 99.99% by metal basis.

20. The process of claim 17, wherein the heating is performed using a plasma process.

21. The process of claim 17, wherein the fine metal powder comprises at least one element selected from nickel, copper, iron, cobalt, silver, gold, platinum, palladium, tin, zirconium, aluminum, silicon, antimony, indium, titanium, tantalum, niobium, and zinc.

22. The process of claim 17, wherein the feed composition comprises at least one substance selected from hydroxide, nitrate, acetate, oxalate, halide, carboxylate and salt.

23. A process for producing fine metal powder comprising:

providing a metal-containing feed composition with purity of at least 99.9% by metal basis;

adding a synthesis aid to the feed composition;

wherein the synthesis aid is selected from the group consisting of emulsifying agent, surfactant and dispersant; and

processing the feed composition and synthesis aid thereby forming the fine metal powder with purity of at least 99.9% by metal basis.

24. The process of claim 23, wherein the processing is conducted at a temperature greater than 600°

C.

25. The process of claim 23, wherein the fine metal powder has a purity greater than 99.99% by metal basis.

27. The process of claim 23, wherein the fine metal powder comprises at least one element selected from nickel, copper, iron, cobalt, silver, gold, platinum, palladium, tin, zirconium, aluminum, silicon, antimony, indium, titanium, tantalum, niobium, and zinc.

28. The process of claim 23, wherein the fine metal powder comprises nanowhiskers.

29. The process of claim 23, wherein the fine metal powder comprises nanorods.