US4668768A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-solvent precipitation process for isolating polymers from solution
Assignee: General Electric Co
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Filing: 1985-11-25
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Granted: 1987-05-26
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Expires: 2005-11-25
Abstract
Abstract A method for isolating polymer resins from organic solvents is provided wherein the organic solvent is vaporized in a separation medium comprised of water and an organic anti-solvent for said polymer without significant vaporization of the organic anti-solvent. The polymer precipitates as a powder without high-speed, high-shear agitation and without the formation of a sticky globular mass.
Inventors
- 👤 Ashok K. Mendiratta
- 👤 Wayne F. Morgan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:53
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
100 words
A process for isolating polymer resins from water-immiscible organic solvents which comprises mixing the organic solvent containing up to 50% by weight polymer within a separation medium comprised of water and an organic anti-solvent for said polymer so as to form both an organic solvent phase and an aqueous phase, while vaporizing the organic solvent without significant vaporization of the organic anti-solvent and recovering a powdery polymer precipitate from the mixture formed, the weight ratio of organic anti-solvent to polymer falling in the range of about 10:1 to 1:1, and said organic anti-solvent being preferentially soluble in said organic solvent.
Claim 2
Dependent Claim
100 words
A process for isolating polymer resins from water-immiscible organic solvents which comprises mixing the organic solvent containing up to 50% by weight polymer within a separation medium comprised of water and an organic anti-solvent for said polymer so as to form both an organic solvent phase and an aqueous phase, while vaporizing the organic solvent without significant vaporization of the organic anti-solvent and recovering a powdery polymer precipitate from the mixture formed, the weight ratio of organic anti-solvent to polymer falling in the range of about 10:1 to 1:1, and said organic anti-solvent being preferentially soluble in said organic solvent.
Claim 3
Dependent Claim
14 words
A process as in claim 1 wherein the organic anti-solvent is immiscible in water.
Claim 4
Dependent Claim
14 words
A process as in claim 1 wherein mixing is achieved with low-speed, low-shear agitation.
Claim 5
Dependent Claim
25 words
A process as in claim 1 wherein the polymer is selected from the group consisting of polycarbonate, polystyrene, polyphenylene ether, polyester, polyetherimide and ethylene-propylene-diene rubbers.
Claim 6
Dependent Claim
21 words
A process as in claim 1 wherein the organic solvents are selected from the group consisting of methylene chloride and toluene.
Claim 7
Dependent Claim
41 words
A process as in claim 1 wherein vaporization of the organic solvent is achieved by heating the mixture formed to a temperature within the range of about 10° C. below to 30° C. above the boiling point of the organic solvent.
Claim 8
Dependent Claim
16 words
A method as in claim 6 wherein less than 10% of the organic anti-solvent is vaporized.
Claim 9
Dependent Claim
99 words
A process for isolating polycarbonate resin from methylene chloride which comprises mixing a methylene chloride solution containing up to about 50% by weight polycarbonate within a separation medium comprised of water and an organic anti-solvent for polycarbonate under conditions of low-speed, low-shear agitation while vaporizing the methylene chloride without significant vaporization of the organic anti-solvent and recovering a powdery polycarbonate from the mixture formed, said organic anti-solvent being selected from the group consisting of n-pentanol, n-hexanol, methylisobutyl ketone, heptane, hexane and methylethyl ketone; the ratio of organic anti-solvent to polycarbonate falling in the range of about 10:1 to 1:1.
Claim 10
Dependent Claim
99 words
A process for isolating polycarbonate resin from methylene chloride which comprises mixing a methylene chloride solution containing up to about 50% by weight polycarbonate within a separation medium comprised of water and an organic anti-solvent for polycarbonate under conditions of low-speed, low-shear agitation while vaporizing the methylene chloride without significant vaporization of the organic anti-solvent and recovering a powdery polycarbonate from the mixture formed, said organic anti-solvent being selected from the group consisting of n-pentanol, n-hexanol, methylisobutyl ketone, heptane, hexane and methylethyl ketone; the ratio of organic anti-solvent to polycarbonate falling in the range of about 10:1 to 1:1.
Claim 11
Dependent Claim
15 words
A method as in claim 8 wherein the polycarbonate is cyclic, low molecular weight polycarbonate.
Claim 12
Independent Claim
109 words
A method for isolating polyphenylene ether resins from toluene which comprises mixing a toluene solution containing up to about 50% by weight polyphenylene ether within a separation medium comprised of water and an anti-solvent for polyphenylene ether under conditions of low-speed, low-shear agitation so as to form both an organic solvent phase and an aqueous phase, while vaporizing the toluene without significant vaporization of said organic anti-solvent and recovering a powdery polyphenylene ether precipitate from the mixture formed, said organic anti-solvent being selected from the group consisting of pentanol, n-hexanol and methylisobutyl ketone; the ratio of anti-solvent to polyphenylene ether falling in the range of about 10:1 to 1:1.
Claim 13
Independent Claim
109 words
A method for isolating polyphenylene ether resins from toluene which comprises mixing a toluene solution containing up to about 50% by weight polyphenylene ether within a separation medium comprised of water and an anti-solvent for polyphenylene ether under conditions of low-speed, low-shear agitation so as to form both an organic solvent phase and an aqueous phase, while vaporizing the toluene without significant vaporization of said organic anti-solvent and recovering a powdery polyphenylene ether precipitate from the mixture formed, said organic anti-solvent being selected from the group consisting of pentanol, n-hexanol and methylisobutyl ketone; the ratio of anti-solvent to polyphenylene ether falling in the range of about 10:1 to 1:1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |