Method of forming polymer particles

• US 20070007677A1
• Filed: 07/08/2005
• Published: 01/11/2007
• Est. Priority Date: 07/08/2005
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Lobo, Lloyd, McHugh, Tomas, Blair, Stewart
• Granted Patent: US 7,273,570 B2
• Time in Patent Office: Days
• US Class Current: 264/8
• CPC Class Codes: B01F 25/74 with rotating parts, e.g. discs
• CPC Class Codes: B01J 19/1887 forming a thin film
• CPC Class Codes: B01J 2219/00094 Jackets
• CPC Class Codes: B01J 2219/00096 Plates
• CPC Class Codes: C08J 3/16 by coagulating dispersions C08J3/122 takes precedence

Abstract

The present invention is a method of manufacturing polymer particles. The method includes providing an oil in water emulsion, wherein the oil phase comprises a volatile solvent and at least one water insoluble polymer. The volatile solvent has a solubility of not more than 10% in water and the water insoluble polymer has a weight average molecular weight of at least 2000. The water insoluble polymer is soluble in the volatile solvent. The emulsion is supplied to a rotating surface of a rotating surface reactor. The temperature of the rotating surface is maintained at the boiling point of said solvent or greater. The rotating surface of the reactor spins at a speed sufficient to cause the emulsion to spread over the rotating surface as a continuously flowing thin film wherein a vapor phase containing the volatile solvent is removed. The water insoluble polymer particles are then collected as a slurry of polymer particles and water.

Claims

1. A method of manufacturing polymer particles comprising:

i) providing an oil in water emulsion, wherein the oil phase comprises a volatile solvent, at least one water insoluble polymer wherein the volatile solvent has a solubility of not more than 10% in water and the water insoluble polymer has a weight average molecular weight of at least 2000, said water insoluble polymer being soluble in the volatile solvent;

ii) supplying the emulsion to a rotating surface of a rotating surface reactor;

iii) maintaining the temperature of the rotating surface at a boiling point of said solvent or greater;

iv) operating the rotating surface reactor so that the rotating surface spins at a speed sufficient to cause the emulsion to spread over the rotating surface as a continuously flowing thin film wherein a vapor phase containing the volatile solvent is removed; and

v) collecting the water insoluble polymer particles as a slurry of polymer particles.

2. The method of claim 1 wherein the spinning disc reactor is operated at a pressure of from 0 to 30 inches of Hg vacuum.

3. The method of claim 1 wherein emulsion is preheated prior to contacting the disc.

4. The method of claim 1 wherein the volatile solvent in the emulsion is from 1 to 50% by weight

5. The method of claim 1 wherein the dissolved polymer concentration in the oil phase is from 1 to 60% by weight.

6. The method of claim 1 wherein a ratio of volatile solvent to water is from 0.1 to 50% by volume

7. The method of claim 1 where the slurry of polymer particles has less than 5% by weight of the volatile solvent

8. The method of claim 10 where the volatile solvent is less than 1% by weight of the final slurry.

9. The method of claim 1 where the slurry of polymer particles further comprises polymeric binders, pigments, waxes or charge control agents.

10. The method as in claim 1 where the vapor phase is collected and condensed.

11. The method as in claim 1 wherein the slurry contains polymer particles having a particle size of from 0.05 μ

m to 100 μ

m.

12. The method as in claim 1 wherein the emulsion contains stabilizers or surfactants.

13. The method as in claim 1 wherein the rotating surface is at a speed of between 100 and 5000 rpm.

14. The method as in claim 1 wherein the emulsion has a residence time on the rotating surface of from 0.1 to 5 seconds.

15. The method as in claim 1 wherein the emulsion has a thickness on the rotating surface of less than 500 μ

m.