FINE SOLID SOLUTION ALLOY PARTICLES AND METHOD FOR PRODUCING SAME

• US 20120094140A1
• Filed: 04/23/2010
• Published: 04/19/2012
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: Japan Science & Technology Trading Co. Limited
• Original Assignee: Japan Science & Technology Trading Co. Limited
• Inventors: Kitagawa, Hiroshi, Kusada, Kohei, Makiura, Rie
• Granted Patent: US 9,273,378 B2
• Time in Patent Office: Days
• US Class Current: 428/544
• CPC Class Codes: B22F 1/054 Nanosized particles
• CPC Class Codes: B22F 9/00 Making metallic powder or suspensions thereof
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C22C 5/02 Alloys based on gold
• CPC Class Codes: C22C 5/04 Alloys based on a platinum group metal
• CPC Class Codes: C22C 5/06 Alloys based on silver
• CPC Class Codes: Y10T 428/12 All metal or with adjacent metals
• CPC Class Codes: Y10T 428/12014 having metal particles

Abstract

The alloy fine particles of the present invention are fine particles of a solid solution alloy, in which a plurality of metal elements are mixed at the atomic level. The production method of the present invention is a method for producing alloy fine particles composed of a plurality of metal elements. This production method includes the steps of: (i) preparing a solution containing ions of the plurality of metal elements and a liquid containing a reducing agent; and (ii) mixing the solution with the liquid that has been heated.

Claims

1-18. -18. (canceled)

19. Fine particles of a solid solution alloy, in which a plurality of metal elements are mixed at the atomic level wherein

the plurality of metal elements are a plurality of metal elements that do not form a solid solution even in the liquid phase.

20. The alloy fine particles according to claim 19, wherein the plurality of metal elements are two kinds of metal elements.

21. The alloy fine particles according to claim 20, wherein elemental mapping using a scanning transmission electron microscope with a resolution of 0.105 nm demonstrates that there is no phase separation in the alloy fine particles.

22. The alloy fine particles according to claim 20, wherein X-ray diffraction demonstrates that there is no phase separation in the alloy fine particles.

23. The alloy fine particles according to claim 21, wherein the plurality of metal elements are silver and rhodium.

24. The alloy fine particles according to claim 21, wherein the plurality of metal elements are gold and rhodium.

25. The alloy fine particles according to claim 19, having an average particle size of 20 nm or less.

26. A method for producing alloy fine particles composed of a plurality of metal elements, the method comprising the steps of:

(i) preparing a solution containing ions of the plurality of metal elements and a liquid containing a reducing agent; and

(ii) mixing the solution with the liquid that has been heated, wherein

the plurality of metal elements are a plurality of metal elements that do not form a solid solution even in the liquid phase.

27. The production method according to claim 26, wherein

the reducing agent is at least one type of alcohol selected from the group consisting of ethylene glycol, diethylene glycol, and triethylene glycol.

28. The production method according to claim 26, wherein

the reducing agent is ethylene glycol, and

in the step (ii), the solution is mixed with the liquid that has been heated to a temperature not lower than a temperature at which each of the ions of the plurality of metal elements is reduced.

29. The production method according to claim 28, wherein

in the step (ii), the solution is mixed with the liquid that has been heated to a temperature higher by 20°

C. or more than a temperature at which each of the ions of the plurality of metal elements is reduced.

30. The production method according to claim 26, wherein

the reducing agent is ethylene glycol,

the plurality of metal elements are silver and rhodium, and

in the step (ii), the solution is mixed with the liquid that has been heated to 145°

C. or higher.

31. The production method according to claim 26, wherein the plurality of metal elements are gold and rhodium.

32. The production method according to claim 26, wherein at least one selected from the liquid and the solution contains a protective agent for preventing agglomeration of the alloy fine particles.

33. The production method according to claim 26, wherein in the step (ii), the solution is mixed with the liquid by dropping the solution into the liquid.

34. The production method according to claim 26, wherein in the step (ii), the solution is mixed with the liquid by spraying the solution onto the liquid.

35. Alloy fine particles produced by the production method according to claim 26, wherein the alloy fine particles are fine particles of a solid solution alloy, in which a plurality of metal elements are mixed at the atomic level.