US4064079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyester polymer recovery
Assignee: Monsanto Co
•
Filing: 1976-04-05
•
Granted: 1977-12-20
•
Expires: 1996-04-05
Abstract
Abstract Polyester fibers are dissolved and solid linear polyester polymer recovered for use in the production of new linear polyester products, particularly polyester fibers or filaments, by the process of dissolving the fibers in a non-depolymerizing dissolution solvent for polyester characterized by inclusion of carbocyclic rings in its structural formula under dissolution conditions for polyester polymer; thereafter quenching the polyester solution; and separating the solid polyester from the solution.
Inventors
- 👤 Norman C. Sidebotham
- 👤 Paul D. Shoemaker
- 👤 Clarence W. Young, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:28
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; C08J11/08; C08J2367/00; C08J2367/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
101 words
A process for recovering solid linear polyester polymer from polyester fibers which comprises the steps of: a. dissolving the polyester fibers in a non-depolymerizing dissolution solvent for polyester under conditions permitting dissolution of high molecular weight polyester without loss of more than 15% of such molecular weight, to form a solution; b. quenching the solution under such conditions that the polyester polymer is caused to precipitate out in a form having a molecular weight of within 15% of the molecular weight of the fibers leaving the solvent in liquid phase; and, c. separating the precipitated polyester polymer from the non-depolymerizing solvent.
Claim 2
Dependent Claim
101 words
A process for recovering solid linear polyester polymer from polyester fibers which comprises the steps of: a. dissolving the polyester fibers in a non-depolymerizing dissolution solvent for polyester under conditions permitting dissolution of high molecular weight polyester without loss of more than 15% of such molecular weight, to form a solution; b. quenching the solution under such conditions that the polyester polymer is caused to precipitate out in a form having a molecular weight of within 15% of the molecular weight of the fibers leaving the solvent in liquid phase; and, c. separating the precipitated polyester polymer from the non-depolymerizing solvent.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the non-depolymerizing solvent is characterized by at least one aromatic ring in its structural formula.
Claim 4
Dependent Claim
31 words
The process of claim 1 wherein the solvent is selected from the group consisting of diphenyl, diphenyl ether, naphthalene, methylnaphthalene, benzophenone, diphenyl methane, acenaphthene, phenanthrene, para-dichlorobenzene, substituted naphthalene and substituted diphenyl.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the quenching medium is a gas.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the quenching medium is a liquid.
Claim 7
Dependent Claim
10 words
The process of claim 1 wherein the solvent is naphthalene.
Claim 8
Dependent Claim
112 words
A process for recovering solid linear polyester polymer from polyester fibers which comprises the steps of: a. dissolving the polyester fibers in a non-depolymerizing dissolution solvent for polyester under conditions permitting dissolution of high molecular weight polyester without loss of more than 15% of such molecular weight, to form a solution; b. quenching the solution with a liquid quenching medium under such conditions that the polyester is caused to precipitate out in a form having a molecular weight of within 15% of the molecular weight of the fibers leaving the solvent and the quenching medium in liquid phase; c. and separating the precipitated polyester polymer from the solvent and the quenching medium.
Claim 9
Dependent Claim
112 words
A process for recovering solid linear polyester polymer from polyester fibers which comprises the steps of: a. dissolving the polyester fibers in a non-depolymerizing dissolution solvent for polyester under conditions permitting dissolution of high molecular weight polyester without loss of more than 15% of such molecular weight, to form a solution; b. quenching the solution with a liquid quenching medium under such conditions that the polyester is caused to precipitate out in a form having a molecular weight of within 15% of the molecular weight of the fibers leaving the solvent and the quenching medium in liquid phase; c. and separating the precipitated polyester polymer from the solvent and the quenching medium.
Claim 10
Dependent Claim
22 words
The process of claim 7 wherein the solvent for polyester is characterized by at least one aromatic ring in its structural formula.
Claim 11
Dependent Claim
21 words
The process of claim 7 wherein the solvent for the polyester is characterized by 2-3 aromatic rings in its structural formula.
Claim 12
Dependent Claim
33 words
The process of claim 7 wherein the solvent for polyester is selected frrom the group consisting of diphenyl, diphenyl ether, naphthalene, methylnaphthalene, benzophenone, diphenyl methane, acenaphthalene, phenanthrene, paradichlorobenzene, substituted naphthalene and substituted diphenyl.
Claim 13
Dependent Claim
12 words
The process of claim 7 wherein the solvent for polyester is naphthalene.
Claim 14
Dependent Claim
18 words
The process of claim 7 wherein the quenching medium is a solvent for the non-depolymerizing solvent for polyester.
Claim 15
Dependent Claim
18 words
The process of claim 7 wherein the quenching medium is a non-solvent for the non-depolymerizing solvent for polyester.
Claim 16
Dependent Claim
38 words
The process of claim 7 wherein the quenching medium is selected from the group consisting of water, dichloromethane, dimethyl formamide, 1,1,1 trichloroethane, naphthalene, acetone, benzene, 2-butanone, dichloromethane, dimethylacetamide, ethanol, methanol, tetrachloromethane, toluene, 1,1,1-trichloroethane, trichloromethane, xylene, and molten 1,4-dichlorobenzene.
Claim 17
Dependent Claim
12 words
The process of claim 7 wherein the quenching medium is dimethyl formamide.
Claim 18
Dependent Claim
11 words
The process of claim 7 wherein the quenching medium is water.
Claim 19
Dependent Claim
11 words
The process of claim 7 wherein the quenching medium is acetone.
Claim 20
Dependent Claim
18 words
The process of claim 7 wherein the non-depolymerizing solvent for polyester and the quenching medium is the same.
Claim 21
Dependent Claim
11 words
The process of claim 7 wherein the polyester is polyethylene terephthalate.
Claim 22
Dependent Claim
13 words
The process of claim 7 wherein the solution contains 10-40% of polyester polymer.
Claim 23
Dependent Claim
11 words
The process of claim 7 wherein the polyester is poly(cyclohexanedimethanol terephthalate).
Claim 24
Dependent Claim
11 words
The process of claim 7 wherein the polyester is poly(butylene terephthalate).
References Cited (Backward Citations)
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Cited
US2762788A
Cited
US2742440A
Cited
US2945840A
Cited
US3696058A
Cited
US3935169A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-19 | 1981-06-20 | 1981-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-19 | 1985-06-20 | 1985-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-19 | 1989-06-20 | 1989-12-20 | $7700.00 | Window Closed / Lapsed |