US4792573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of ultra-high molecular weight polyester
Assignee: Goodyear Tire and Rubber Co
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Filing: 1988-04-01
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Granted: 1988-12-20
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Expires: 2008-04-01
Abstract
Abstract There is a growing demand for high molecular weight polyester resin. For instance, the market for high molecular weight polyethylene terephthalate resin is rapidly expanding. High molecular polyethylene terephthalate resin is currently being used in vast quantities in manufacturing bottles for carbonated beverages, trays for frozen foods which can be heated in either microwave ovens or convection ovens, and in tire cord. There is a growing trend toward higher molecular weights in many applications for such polyester resins. Unfortunately, it becomes progressively more difficult and expensive to produce polyester resins having higher and higher molecular weight utilizing standard commerical polymerization techniques. This invention discloses a technique by which polyester resin having extremely high molecular weight can be prepared utilizing a very rapid solid state polymerization process. This invention more specifically discloses a process for preparing ultra-high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent; (2) recovering the polyester prepolymer from the organic solvent to produce a porous, fibrous mass of the polyester prepolymer; and (3) solid state polymerizing the porous, fibrous mass at an elevated temperature to produce the ultra-high molecular weight polyester resin.
Inventors
- 👤 Gerald Cohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:12
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/28; C08G; C08G63/00; C08G63/78; C08G63/80; C08J2367/00; C08J2367/02
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
61 words
A process for preparing ultra-high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent; (2) recovering the polyester prepolymer from the organic solvent to produce a porous, fibrous mass of the polyester prepolymer; and (3) solid state polymerizing the porous, fibrous mass at an elevated temperature to produce the ultra-high molecular weight polyester resin.
Claim 2
Dependent Claim
61 words
A process for preparing ultra-high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent; (2) recovering the polyester prepolymer from the organic solvent to produce a porous, fibrous mass of the polyester prepolymer; and (3) solid state polymerizing the porous, fibrous mass at an elevated temperature to produce the ultra-high molecular weight polyester resin.
Claim 3
Dependent Claim
58 words
In a process for solid state polymerizing a polyester prepolymer into a high molecular weight polyester resin at an elevated temperature, the improvement which comprises utilizing a polyester prepolymer which is in the form of a porous, fibrous mass which was prepared by recovering the polyester prepolymer from a solution of the polyester prepolymer in an organic solvent.
Claim 4
Dependent Claim
58 words
In a process for solid state polymerizing a polyester prepolymer into a high molecular weight polyester resin at an elevated temperature, the improvement which comprises utilizing a polyester prepolymer which is in the form of a porous, fibrous mass which was prepared by recovering the polyester prepolymer from a solution of the polyester prepolymer in an organic solvent.
Claim 5
Dependent Claim
26 words
A process as specified in claim 2 wherein the polyester prepolymer is recovered from the solution of the polyester prepolymer in the organic solvent by coagulation.
Claim 6
Dependent Claim
27 words
A process as specified in claim 1 wherein the polyester prepolymer is recovered from the organic solvent in the form of a porous, fibrous mass by coagulation.
Claim 7
Dependent Claim
186 words
A process as specified in claim 4 wherein said polyester prepolymer is comprised of repeat units which are derived from a diacid component and a diol component; wherein said diacid component is at least one member selected from the group consisting of alkyl dicarboxylic acids which contain from 4 to 36 carbon atoms, diesters of alkyl dicarboxylic acids which contain from 6 to 38 carbon atoms, aryl dicarboxylic acids which contain from 8 to 20 carbon atoms, diesters of aryl dicarboxylic acids which contain from 10 to 22 carbon atoms, alkyl substituted aryl dicarboxylic acids which contain from 9 to 22 carbon atoms, or diesters of alkyl substituted aryl dicarboxylic acids which contain from 11 to 22 carbon atoms and wherein said diol component is at lest one member selected from the group consisting of glycols containing from 2 to 12 carbon atoms, glycol ethers containing from 4 to 12 carbon atoms, and polyether glycols having the structural formula HO--(A--O)-- n -- H wherein A is an alkylene group containing from 2 to 6 carbon atoms and wherein n is an integer from 2 to 400.
Claim 8
Dependent Claim
14 words
A process as specified in claim 4 wherein the polyester prepolymer is polyethylene terephthalate.
Claim 9
Dependent Claim
22 words
A process as specified in claim 6 wherein said polymerization is carried out in the presence of at least one inert gas.
Claim 10
Dependent Claim
31 words
A process as specified in claim 7 wherein said solid state polymerization is conducted in a static bed reactor wherein the porous, fibrous mass is in the form of porous pills.
Claim 11
Dependent Claim
33 words
A process as specified in claim 8 wherein the porous pills move from the top to the bottom of the reactor by reason of the force of gravity in a partially dammed state.
Claim 12
Dependent Claim
13 words
A process as specified in claim 9 wherein said inert gas is nitrogen.
Claim 13
Dependent Claim
21 words
A process as specified in claim 2 wherein the polyester prepolymer has an intrinsic viscosity of at least about 0.2 dl/g.
Claim 14
Dependent Claim
26 words
A process as specified in claim 2 wherein the polyester prepolymer has an intrinsic viscosity which is within the range of about 0.3 to 2.0 dl/g.
Claim 15
Dependent Claim
19 words
A process as specified in claim 6 wherein the organic solvent is a trifluoroacetic acid/methylene chloride mixed solvent system.
Claim 16
Dependent Claim
25 words
A process as specified in claim 13 wherein the coagulation is done by utilizing a member selected from the group consisting of alcohols and ketones.
Claim 17
Dependent Claim
35 words
A process as specified in claim 13 wherein the organic solvent is comprised of from about 25 to about 75 weight percent trifluoroacetic acid and from about 25 to about 75 weight percent methylene chloride.
Claim 18
Dependent Claim
16 words
A process as specified in claim 15 wherein the coagulation is done by utilizing an alcohol.
Claim 19
Dependent Claim
12 words
A process as specified in claim 16 wherein the alcohol is methanol.
Claim 20
Dependent Claim
14 words
A process as specified in claim 2 wherein the polyester prepolymer is polyethylene naphthalate.
Claim 21
Dependent Claim
27 words
A process as specified in claim 10 wherein the polyester prepolymer has an intrinsic viscosity which is within the range of about 0.4 to about 0.6 dl/g.
Claim 22
Dependent Claim
19 words
A process as specified in claim 8 wherein the porous pills are made by compacting the porous, fibrous mass.
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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) | 1991-12-20 | 1992-06-20 | 1992-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-20 | 1996-06-20 | 1996-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-20 | 2000-06-20 | 2000-12-20 | $7700.00 | Window Closed / Lapsed |