Multicomponent powder mixing process and compositions produced thereby

• US 5,628,945 A
• Filed: 08/03/1992
• Issued: 05/13/1997
• Est. Priority Date: 08/03/1992
• Status: Expired due to Fees

• Current Assignee: Rutgers University College of Engineering Department of Ceramics
• Original Assignee: Rutgers University College of Engineering Department of Ceramics
• Inventors: Riman, Richard E., Mort, Paul R. III
• Primary Examiner(s): Lovering, Richard D.
• Application Number:
  US07/925,719
• Time in Patent Office: 1,744 Days
• Field of Search: 252/183.11, 252/183.12, 252/183.13, 264/4.4, 264/7, 264/117, 264/113, 427/213.3, 427/213.31, 427/213.36, 427/222, 427/190, 427/193, 71/64.02, 71/64.05, 424/459, 424/470, 514/951, 521/919, 501/29, 501/135, 419/64, 419/65, 419/66
• US Class Current: 264/117
• CPC Class Codes: B01J 2/12 in rotating drums
• CPC Class Codes: C03C 12/02 Reflective beads
• CPC Class Codes: C03C 14/004 the non-glass component being in the form of particles or flakes
• CPC Class Codes: C03C 2214/05 surface treated, e.g. coated

Abstract

A method for controlling chemical distribution of substances in a solid state (and products produced thereby), the method comprising the steps of mixing particles of a first powder and a triggerable granule facilitator to form first microcapsules, the first microcapsules each having a core of one of the particles and a cladding of the facilitator; and triggering the facilitator while dry mixing the microcapsules to form substantially spherical granules of the microcapsules, the granules each having a controlled chemical distribution.

The method also includes the steps of mixing particles of a second powder with the facilitator to form second microcapsules, the second microcapsules each having a core of one of the particles of the second powder and a cladding of the facilitator; and then mixing the first and the second microcapsules prior to said triggering step.

The method further includes the step of the triggering, mixing the first microcapsules and a second triggerable granule facilitator to form a second cladding on the first microcapsules. To any of the foregoing, there can be the further step of pyrolyzing the microcapsules to remove a portion of the facilitator but leave a resulting pyrolysis product, forming a distribution of the pyrolysis product and the particles. Thereafter, if desired, there follows the step of heating the distribution of the pyrolysis product and the particles to induce a solid state reaction between the pyrolysis product and the particles of the first powder.

Claims

1. A method for controlling chemical distribution of dry substances, the method comprising the steps of:

(a) dry mixing particles of a first powder and a triggerable granule facilitator to form first microcapsules, the first microcapsules each having a core of one of the particles and a coating of the facilitator;

(b) further dry mixing at a speed sufficient to cause increased frictional interaction between the microcapsules, thereby triggering the facilitator while dry mixing the microcapsules to form granules of the microcapsules by an aggregation process; and

(c) ceasing the dry mixing while maintaining the granules of the microcapsules in a dry phase.

2. The method of claim 1, further comprising the step of:

forming an undercoating on each of said first particles so that the triggerable granule facilitator forms a second coating of the first particles.

3. The method of claim 2, further comprising the steps of:

mixing particles of a second powder with the facilitator to form second microcapsules, the second microcapsules each having a core of one of the particles of the second powder and a coating of the facilitator; and

mixing the first and the second microcapsules prior to said triggering step so that the triggering step will form the granules from a random distribution of the first and second microcapsules.

4. The method of claim 1, further comprising the steps of:

mixing particles of a second powder with the facilitator to form second microcapsules, the second microcapsules each having a core of one of the particles of the second powder and a coating of the facilitator; and

mixing the first and the second microcapsules prior to said triggering step so that the triggering step will form the granules from a random distribution of the first and second microcapsules.

5. The method of claim 1, further comprising the steps of:

mixing particles of a second powder with the facilitator to form second microcapsules, each having a core of one of the particles of the second powder and a coating of the facilitator;

mixing the second microcapsules with the granules; and

retriggering said facilitator to form a granular cladding of the second microcapsules on each of the granules.

6. The method of claim 5, further comprising the step of:

first mixing the particles of the first powder and a substance other than the triggerable granule facilitator to form an undercoating on each of said first particles so that the first triggerable granule facilitator forms a second coating of the first particles.

7. The method of claim 5, further comprising the step of:

first mixing the particles of the second powder and a substance other than the granule facilitator to form an undercoating on each of said second particles so that the triggerable granule facilitator forms a second coating of the second particles.

8. The method of claim 1, further comprising the steps of:

mixing particles of a second powder with a second facilitator to form second microcapsules, the second microcapsules each having a core of one of the particles of the second powder and a coating of the second facilitator;

mixing the granules with the second microcapsules; and

triggering said second facilitator without triggering said first facilitator to form a granular cladding of the second microcapsules and the second facilitator on each of the granules.

9. The method of claim 8, further comprising the step of:

first mixing the particles of the first powder and a substance other than the triggerable granule facilitator to form an undercoating on each of said first particles so that the first triggerable granule facilitator forms a second coating of the first particles.

10. The method of claim 8, further comprising the step of:

first mixing the particles of the second powder and a substance other than the granule facilitator to form an undercoating on each of said second particles so that the triggerable granule facilitator forms a second coating of the second particles.

11. The method of any one of claims 1-10, wherein the mixing is carried out with a mechanofusion device.

12. The method of any one of claims 1-10, further comprising the step of:

pyrolyzing the microcapsules sufficiently to remove a portion of the facilitator but leave a pyrolysis product, forming a distribution of the pyrolysis product and the particles.

13. The method of any one of claims 1-10, wherein at least some of said mixing is high shear mixing.

14. The method of any one of claims 1, 4, 5, or 8, further comprising the step of:

pyrolyzing the microcapsules sufficiently to remove the facilitator, forming a distribution of the particles.

15. The method of any one of claims 1, 4, 5 or 8 , further comprising the step of:

heating the distribution sufficiently to induce mass transport chemical distribution.

16. The method of claim 11, further comprising the step of:

pyrolyzing the microcapsules to leave a pyrolysis product, forming a distribution of the pyrolysis product and the particles.

17. The method of claim 16, further comprising the step of:

heating the distribution of the pyrolysis product and the particles sufficiently to induce a mass transport chemical distribution.

18. The method of claim 17, wherein the step of mixing is carried out with the first facilitator being a metalorganic soap.

19. The method of claim 18, wherein the step of mixing is carried out with the first powder being a ceramic.

20. The method of claim 12, further comprising the step of:

heating the distribution of the pyrolysis product and the particles to induce a mass transport chemical distribution.

21. The method of claim 20, wherein the step of mixing is carried out with the first facilitator being a metalorganic soap.

22. The method of claim 20 wherein the step of mixing is carried out with the first powder being a ceramic.

23. The method of claim 12, further comprising the step of:

inducing a solid state chemical reaction resulting in a phase pure, multicomponent compound.

24. The method of claim 12, wherein the heating step includes heating sufficiently to induce a solid state chemical reaction resulting in a multiphase ensemble of compounds.

25. A method for controlling chemical distribution of substances, the method comprising the steps of:

coating particles of a first powder to form microcapsules;

pyrolyzing the microcapsules in a solid state to leave a resulting pyrolysis product, forming a distribution of the pyrolysis product and the particles; and

heating the distribution of the pyrolysis product and the particles to induce mass transport chemical distribution in a solid state.

26. The method of claim 25, wherein the heating step includes:

inducing a solid state chemical reaction resulting in a phase pure, multicomponent compound.

27. The method of claim 25, further comprising the step of inducing a solid state chemical reaction resulting in a multiphase ensemble of compounds.

28. The method of claim 25 wherein the particles are finer than 325 mesh.

29. The method of claim 25 wherein the particles are organic particles.

30. The method of claim 25 wherein the particles are inorganic particles.

31. The method of claim 25, wherein the pyrolysis product is derived from the coating on core particles, not cladding particles, in a multilayer granule.

32. The method of claim 25, wherein the pyrolysis product is derived from the coating on cladding particles, not core particles, in a multilayer granule.

33. The method of claim 25, wherein the step of coating includes the steps of:

(a) dry mixing particles of a first powder and a triggerable granule facilitator to form first microcapsules, the first microcapsules each having a core of one of the particles and a coating of the facilitator;

(b) further dry mixing at a speed sufficient to cause increased frictional interaction between the microcapsules, thereby triggering the facilitator while dry mixing the microcapsules to form granules of the microcapsules by an aggregation process; and

(c) ceasing the dry mixing while maintaining the granules of the microcapsules in a dry phase.

34. A method according to claim 25, wherein the step of coating particles comprises dry coating particles of the first powder to form microcapsules.

35. A method for controlling chemical distribution of substances, the method comprising the steps of:

coating particles of a first powder to form microcapsules;

pyrolyzing the microcapsules to leave a resulting pyrolysis product,

forming a distribution of the pyrolysis product and the particles; and

heating the distribution of the pyrolysis product and the particles to induce mass transport chemical distribution in a solid state,

wherein the coating includes a triggerable granule facilitator which is finer than 325 mesh.