Hollow nano-particles and method thereof

• US 20080286374A1
• Filed: 12/20/2006
• Published: 11/20/2008
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Bridgestone Corporation
• Original Assignee: Bridgestone Corporation
• Inventors: Wang, Xiaorong, Sadhukhan, Pat, Rackaitis, Mindaugas
• Granted Patent: US 8,877,250 B2
• Time in Patent Office: Days
• US Class Current: 424/497
• CPC Class Codes: B01J 13/14 Polymerisation; cross-linking
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08F 236/10 with vinyl-aromatic monomers
• CPC Class Codes: C08F 257/02 on to polymers of styrene or alkyl-substituted styrenes
• CPC Class Codes: C08J 2201/0502 the liquid phase being organic
• CPC Class Codes: C08J 2353/02 of vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C08J 9/286 the liquid phase being a solvent for the monomers but not for the resulting macromolecular composition, i.e. macroporous or macroreticular polymers
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10T 428/249972 Resin or rubber element
• CPC Class Codes: Y10T 428/2985 Solid-walled microcapsule from synthetic polymer

Abstract

The invention provides a hollow nano-particle comprising a crosslinked shell and a void core; and a preparation method thereof. The hollow nano-particle may be used in rubber composition, tire product, and pharmaceutical delivery system etc.

Claims

1. A method of preparing hollow nano-particles, which comprises

(A) in a first solvent, providing a first polymer globule which is insoluble in the first solvent;

(B) adding to the first solvent a second polymer, which is soluble in the first solvent, and a third polymer, which is insoluble in the first solvent;

(C) copolymerizing the second polymer with the third polymer;

(D) around the first polymer globule, assembling a micelle from the block copolymers which comprise the second polymer blocks and the third polymer blocks;

(E) crosslinking the third polymer blocks; and

(F) in a second solvent in which the first polymer globule is soluble, dissolving out at least a portion of the first polymer globule from inside the micelle to form a hollow or void core.

2. The method according to claim 1, in which the first solvent comprises a non-aromatic hydrocarbon solvent selected from the group consisting of aliphatic hydrocarbon, alicyclic hydrocarbon, and mixture thereof.

3. The method according to claim 1, in which the “

providing a first polymer globule”

is realized by anionically polymerizing monomer of formula (I) as shown below;

4. The method according to claim 3, in which the monomer of formula (I) comprises styrene.

5. The method according to claim 1, in which the size of the first polymer globule or the size of the void core is in a range of from about 1 nm to about 500 nm.

6. The method according to claim 1, in which the “

adding to the first solvent a second polymer”

comprises adding to the first solvent a second polymer which is polymerized from monomer of formula (II) as shown below;

7. The method according to claim 1, in which the second polymer of step (B) comprises poly(1,3-butadiene).

8. The method according to claim 1, in which the third polymer of step (C) comprises an anionically polymerized monomer of formula (III) as shown below:

9. The method according to claim 8, in which the monomer of formula (III) comprises styrene.

10. The method according to claim 1, in which the crosslinking in Step (E) is carried out by using a di-vinyl- or tri-vinyl-substituted aromatic hydrocarbon.

11. The method according to claim 10, in which the aromatic hydrocarbon comprises divinylbenzene (DVB).

12. The method according to claim 1, in which the second solvent in Step (F) is selected from the group consisting of benzene, toluene, xylene, THF, HCCl3, and mixture thereof.

13. The method according to claim 1, which optionally comprises a further step of separating the first polymer and the hollow nano-particle by centrifuging, precipitation, and/or phase separation.

14. The method according to claim 1, in which the block copolymer formed in Steps (B) and (C) has a Mw of about 100 to 100,000,000.

15. The method according to claim 1, in which the block copolymer chain formed in Steps (B) and (C) comprises 1 to 99% by weight of the second polymer block and 99 to 1% by weight of the third polymer block.

16. The method according to claim 1, in which the final hollow nano-particle has a Mw of between about 1,000 and 10,000,000,000.

17. The method according to claim 1, in which the final hollow nano-particle has a dispersity less than about 2.5.

18. The method according to claim 1, in which the size of the final hollow nano-particle is in a range of from about 2 nm to about 300 nm.

19. The method according to claim 1, in which an anionic initiator is used in Steps (A), (B) and/or (C).

20. The method according to claim 19, in which the anionic initiator is functionalized with amine, formyl, carboxylic acids, alcohol, tin, silicon, silyl ether, or mixture thereof.

21. The method according to claim 1, further including a step of hydrogenation of the shell of the hollow particle.

22. The method according to claim 1, further including a step of crosslinking of the shell of the hollow particle

23. A hollow nano-particle, which comprises a crosslinked shell and a void core, in which the size of the void core is in a range of from about 1 nm to less than about 500 nm.

24. The hollow nano-particle according to claim 23, in which the size of the void core is in a range of from about 1 nm to about 200 nm.

25. The hollow nano-particle according to claim 23, which has a Mw of between about 100 and 100,000,000.

26. The hollow nano-particle according to claim 23, which has a Mw of between about 1,000 and 1,000,000.

27. The hollow nano-particle according to claim 23, which has a ball shape or collapsed ball shape.

28. The hollow nano-particle according to claim 23, which has a dispersity less than about 2.5.

29. The hollow nano-particle according to claim 23, which has a size of from about 1 nm to about 500 nm.

30. The hollow nano-particle according to claim 23, which has a size of from about 1 nm to about 200 nm.

31. The hollow nano-particle according to claim 23, which has a size of from about 5 nm to about 80 nm.

32. A pharmaceutical delivery system, comprising the hollow nano-particle according to claim 23.

33. A rubber composition, comprising the hollow nano-particle according to claim 23.

34. A tire product, comprising the hollow nano-particle according to claim 23.

35. A nanoparticle comprising at least three-regions, a first region comprising at least a partial evacuation of a first polymer;

a second region comprising a second polymer, said second region is adjacent to said first region;

a third region comprising a third polymer;

wherein said second region is between said first region and said third region.