Methods of making cellulose ester microbeads with solvent recovery and recycle
AssigneeEastman Chemical Company
InventorsRobert David Pace, Timothy R. Pitts, Glenn Lewis Shoaf, Gary Kenneth Weakley, Kenny Randolph Parker, Michael John Visneski
Life of this patent
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Abstract
Methods of making cellulose ester (CE) microbeads are provided. The CE microbeads are produced by forming initial CE microparticles suspended in a liquid phase, and converting the microparticles to hardened CE microbeads. The produced microbeads are biodegradable, and have enhanced solidity, sphericity, and smoothness.
Claims21
A method of making cellulose ester (CE) microbeads, the method comprising:
- (a) dissolving a CE in a solvent to produce a CE dope;
- (b) combining at least a portion of the CE dope and an aqueous mixture to produce an initial emulsion;
- (c) converting at least a portion of the initial emulsion into a dispersion comprising a solid phase and a liquid phase, wherein the solid phase comprises hardened CE microbeads and the liquid phase comprises at least a portion of the solvent and at least a portion of the aqueous mixture;
- and
- (d) recovering a solvent-enriched stream from at least a portion of the liquid phase, wherein at least 50 weight percent of the solvent used in the dissolving of step (a) is recycled solvent originating from the solvent-enriched stream.
A method of making cellulose ester (CE) microbeads, the method comprising:
- (a) dissolving a CE in a solvent to produce a CE dope;
- (b) combining at least a portion of the CE dope and an aqueous mixture to produce an initial emulsion;
- (c) converting at least a portion of the initial emulsion into a pre-hardened dispersion comprising pre-hardened solid particles;
- (d) contacting at least a portion of the pre-hardened solid particles with a drowning liquid to form a hardened dispersion comprising a hardened solid phase and a liquid phase, wherein the hardened solid phase comprises hardened CE microbeads;
- and
- (e) recovering a water-enriched stream from at least a portion of the liquid phase, wherein at least 50 weight percent of the drowning liquid used in the contacting of step (d) is recycled water originating from the water-enriched stream.
A method of making cellulose ester (CE) microbeads, the method comprising:
- (a) dissolving a CE in a solvent to produce a CE dope;
- (b) combining at least a portion of the CE dope and an aqueous mixture to produce an initial emulsion;
- (c) converting at least a portion of the initial emulsion into a pre-hardened dispersion comprising pre-hardened solid particles;
- (d) contacting at least a portion of the pre-hardened solid particles with a drowning liquid to produce a hardened dispersion comprising a hardened solid phase and a liquid phase, wherein the hardened solid phase comprises hardened CE microbeads;
- (e) separating at least a portion of the hardened dispersion into a solid-enriched portion and a separated mother liquor stream;
- (f) distilling at least a portion of the separated mother liquor stream to form at least a water-enriched stream and a solvent-enriched stream;
- (g) utilizing at least a portion of the solvent-enriched stream as at least a portion of the solvent in the dissolving of step (a);
- (h) utilizing a first portion of the water-enriched stream as at least a portion of the aqueous mixture in the combining of step (b);
- and
- (i) utilizing a second portion of the water-enriched stream as at least a portion of the drowning liquid in the contacting of step (d).
21-30. (canceled)
Dependencies are inferred from the claim text.