Optimized emulsion drying process for making micronized polyetherimide polymers
View Patent ↗A process for making ultra-fine particles of a high performance polymer in a yield greater than 90%, which includes dissolving the high performance polymer in an organic solvent capable of dissolving the polymer to form a solution; emulsifying the solution by combining the solution with water and a surfactant to form an emulsion; transferring the emulsion into a receiving water containing a surfactant to remove the organic solvent and form a slurry; and recovering particles of less than 75 microns in diameter in a yield greater than 90%.
1. A process for the manufacture of ultra-fine particles of a high performance polymer in a yield greater than 90%, comprising:
a. dissolving the high performance polymer in an organic solvent capable of dissolving the polymer to form a solution;
b. emulsifying the solution by combining the solution with water and a surfactant to form an emulsion;
c. transferring the emulsion into a receiving water containing a surfactant to remove the organic solvent and form a slurry; and,
d. recovering particles of <75-micron diameter in a yield greater than 90%;
wherein the high performance polymer is a polyetherimide.
2. The process according to claim 1 , further comprising heating the emulsion up to or below the boiling point of the emulsion before transferring the emulsion into the receiving water.
3. The process according to claim 1 , further comprising heating the emulsion above the boiling point of the emulsion before transferring the emulsion into the receiving water.
4. The process according to claim 1 , farther comprising transferring the emulsion drop wise into the receiving water.
5. The process according to claim 1 , further comprising transferring the emulsion through a nozzle into the receiving water.
6. The process according to claim 1 , further comprising transferring the emulsion through a tube into the receiving water.
7. The process according to claim 1 , wherein the receiving water is de ionized.
8. The process according to claim 1 , further comprising matching the amount of surfactant in the receiving water to the amount of the surfactant in the emulsion.
9. The process according to claim 8 , wherein the step of matching raises the yield of particles above 98%.
10. The process according to claim 1 , wherein the solvent is a member selected from the group of methylene chloride, chloroform, and combinations thereof.
11. The process according to claim 1 , wherein the solvent has a boiling point that is less than 100 C and the solvent is immiscible with water.
12. The process according to claim 1 , further comprising agitating the solution of step b. to form the emulsion.
13. The process according to claim 1 , further comprising agitating the solution of step b. using a high shear mixer to form the emulsion.
14. The process according to claim 1 , further comprising adding a defoaming agent in step c.
15. The process of claim 1 , further comprising recovering particles in a yield from about 94% to about 99%.
16. The process of claim 1 , wherein the surfactant is anionic surfactant.
17. The process of claim 1 , wherein the surfactant is a surfactant selected from the group of sodium dodecyl benzene sulfonate (SDBS), sodium lauryl sulfate, and combinations thereof.
18. The process according to claim 1 , further comprising filtering the slurry to form a wet cake.
19. The process according to claim 1 , further comprising a course pre-filtering of the slurry to remove any macro particles or contaminates.
20. The process according to claim 18 , further comprising washing or re-slurrying the wet cake with de-ionized water.
21. The process according to claim 20 , further comprising drying the wet cake under heat and vacuum.
22. A process of forming ultra-fine particles of a polyetherimide (PET) polymer in a yield greater than 90% comprising:
a. dissolving a polyetherimide (PEI) polymer in a solvent to form a solution, wherein the polyetherimide is soluble in the solvent, the solvent has a boiling point that is less than 100 C and the solvent is immiscible with water;
b. emulsifying the solution by combining the solution with de-ionized water and a surfactant under agitation conditions sufficient to form an emulsion;
c. transferring the emulsion into a de-ionized receiving water, the receiving water also containing a surfactant and removing the solvent and form a slurry;
d pre-filtering the slurry to remove any macro particles or contaminates
e. filtering the slurry to form a wet cake;
f. washing or re-slurrying the wet cake with de-ionized water;
g. drying the washed wet cake under heat and vacuum; and,
h. recovering particles of polyetherimide (PET) of <75-micron diameter in a yield from about 94% to about 99%.
23. The process of claim 22 , wherein the solvent is methylene chloride.
24. The process according to claim 22 , further comprising combining a de-foaming agent in step c.
25. The process according to claim 22 , further comprising matching the amount of surfactant in the receiving water to the amount of the surfactant in the emulsion.
26. The process according to claim 25 , wherein the surfactant is sodium dodecyl benzene sulfonate (SDBS) or sodium dodecyl sulfate (SLS).
27. The process of claim 1 , wherein the high performance polymer comprises (a) a polyetherimide resin, and (b) a phosphorus-containing stabilizer, in an amount that is effective to increase the melt stability of the polyetherimide resin, wherein the phosphorus-containing stabilizer exhibits a low volatility such that, as measured by thermogravimetric analysis of an initial amount of a sample of the phosphorus-containing stabilizer, greater than or equal to 10 percent by weight of the initial amount of the sample remains unevaporated upon heating of the sample from room temperature to 300° C. at a heating rate of a 20° C. per minute under an inert atmosphere.
28. The process of claim 27 , wherein the phosphorous-containing stabilizer has a formula P—R′ a , where R′ is independently H, alkyl, alkoxy, aryl, aryl oxy, or oxy substituent and a is 3 or 4.
29. The process of claim 22 , wherein the polyetherimide polymer comprises (a) a polyetherimide resin, and (b) a phosphorus-containing stabilizer, in an amount that is effective to increase the melt stability of the polyetherimide resin, wherein the phosphorus-containing stabilizer exhibits a low volatility such that, as measured by thermogravimetric analysis of an initial amount of a sample of the phosphorus-containing stabilizer, greater than or equal to 10 percent by weight of the initial amount of the sample remains unevaporated upon heating of the sample from room temperature to 300° C. at a heating rate of a 20° C. per minute under an inert atmosphere.
30. The method of claim 29 , wherein the phosphorous-containing stabilizer has a formula P—R′ a , where R′ is independently H, alkyl, alkoxy, aryl, aryloxy, or oxy substituent and a is 3 or 4.