US3869427A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of linear polyester with organic monoepoxide
Assignee: EIDP Inc
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Filing: 1966-11-23
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Granted: 1975-03-04
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Expires: 1986-11-23
Abstract
Abstract An improvement in the process of preparing polyester filaments is disclosed as providing reinforced yarns and cords of polyester having low free-carboxyl-group contents which give superior performance in pneumatic tires and other reinforced rubber articles where heat-degradation is a problem. Reduction of free carboxyl groups is achieved by mixing with the molten polyester, prior to melt-spinning, 1,2-epoxy-3-phenoxypropane or 1,2-epoxy3-n-hexyloxypropane.
Inventors
- 👤 Robert Walter Meschke
- 👤 William Harrison Watson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:10
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/40; C08G63/42; C08G63/78; C08G63/785
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
25 words
IN THE PREPARATION OF SYNTHETIC LINEAR TEREPHTHALATE CONDENSATION POLYESTER IN WHICH AT LEAST ABOUT 85% OF THE RECURRING STRUCTURAL UNITS ARE UNITS OF THE FORMULA:
Claim 2
Dependent Claim
25 words
IN THE PREPARATION OF SYNTHETIC LINEAR TEREPHTHALATE CONDENSATION POLYESTER IN WHICH AT LEAST ABOUT 85% OF THE RECURRING STRUCTURAL UNITS ARE UNITS OF THE FORMULA:
Claim 3
Dependent Claim
13 words
A process as defined in claim 1 wherein the monoepoxide is 1, 2-epoxy-3-phenoxypropane.
Claim 4
Dependent Claim
13 words
A process as defined in claim 1 wherein the monoepoxide is 1, 2-epoxy-3-n-hexyloxypropane.
Claim 5
Dependent Claim
22 words
A process as defined in claim 1 wherein the monoepoxide is added to and mixed with the molten polyester under superatmospheric pressure.
Claim 6
Dependent Claim
40 words
A process as defined in claim 1 wherein said polyester after polymerization has a relative viscosity of at least 45, determined as a 10% solution at 25*C. in a mixture of 10 parts phenol and 7 parts 2,4,6-trichlorophenol by weight.
Claim 7
Dependent Claim
64 words
A process as defined in claim 5 wherein the polyester is prepared by ester interchange reaction in the presence of manganous acetate catalyst followed by melt polymerization in the presence of phosphoric acid to at least 45 relative viscosity before adding the monoepoxide to the molten polyester, the molar ratio of phosphoric acid to manganous acetate being within the range of 0.9-2.0 to 1.
Claim 8
Dependent Claim
73 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fiber-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1,2-epoxy-3-phenoxy-propane in an amount providing less than 3 mol per cent based on the polyethylene terephthalate and at least 0.1 mol per equivalent of free carboxyl groups present in the polyethylene terephthalate prior to addition of the 1,2-epoxy 3-phenoxy propane for 1 minute to about 45 minutes.
Claim 9
Dependent Claim
73 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fiber-forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1,2-epoxy-3-phenoxy-propane in an amount providing less than 3 mol per cent based on the polyethylene terephthalate and at least 0.1 mol per equivalent of free carboxyl groups present in the polyethylene terephthalate prior to addition of the 1,2-epoxy 3-phenoxy propane for 1 minute to about 45 minutes.
Claim 10
Dependent Claim
43 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fiber forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1,2-epoxy-3-phenoxy propane in an amount between 0.5 and 2.0 weight percent based on the polyethylene terephthalate.
Claim 11
Dependent Claim
43 words
A process for reducing the concentration of free carboxyl groups in a synthetic linear fiber forming polyethylene terephthalate comprising reacting said polyethylene terephthalate in molten form with 1,2-epoxy-3-phenoxy propane in an amount between 0.5 and 2.0 weight percent based on the polyethylene terephthalate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |