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US4374960A Expired / Lapsed US ⏱️ 0.0 years remaining

Production of polyester fibers of improved stability

Assignee: Honeywell International Inc
•
Filing: 1981-09-16
•
Granted: 1983-02-22
•
Expires: 2001-09-16
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Abstract

Abstract There is provided by this invention a process for the production of high molecular weight linear polyethylene terephthalate condensation polyesters which are useful especially for preparing specialty fibers which have excellent resistance to degradation so that they can be used in such commercial articles as paper making machine fabric, industrial belting, etc. The improved high molecular weight linear polyethylene terephthalate condensation polyester specialty fibers are characterized by improved hydrolytic stability and by reduction in the free carboxyl content so as to have a carboxyl concentration of less than about 6 gram equivalents per 10 6 grams of the polyester. These polyester specialty fibers are prepared by the steps of adding an end capping reagent to particles of the said feed polymer, heating to obtain a homogeneous mixture of the said polyester and end capping reagent, mechanically working the polyester melt, and forming filaments of the linear polyester having a reduced free carboxyl content.

Inventors

  • 👤 Ronald E. Rothwell
  • 👤 Hugh H. Rowan
  • 👤 James J. Dunbar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 08:29
CPC Classifications
D; D01; D01F; D01F6/00; D01F6/88; D01F6/92; C; C08; C08G; C08G63/00; C08G63/91; C08G63/914; C08G63/916; C08K; C08K5/00; C08K5/0008

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 167 words
A process for the preparation of high molecular weight linear polyethylene terephthalate condensation polyesters, said polyesters being characterized by improved hydrolytic stability and by reduction in the free carboxyl content so as to have a carboxyl concentration of less than about 5 gram equivalents per 10 6 grams of polyester, the process comprising the steps of adding an end capping reagent in an amount of about 5 to 170 gram moles per 10 6 grams of polyester, wherein the end capping reagent is selected from the group consisting of N-epoxyalkylimides of dicarboxylic acids, long chain aliphatic epoxides, ethylene carbonate, diazomethane, monoglycidyl ethers, and mixtures thereof, to particles of the said linear polyester, heating the mixture to obtain a substantially homogeneous mixture of said polyester, while subjecting said mixture to extrusion and spinning for a residence time of about 5 to 10 minutes to produce monofilaments of said linear polyester of reduced free carboxyl content of less than about 5 gram equivalents per 10 6 grams of polyester.
Claim 2
Dependent Claim 167 words
A process for the preparation of high molecular weight linear polyethylene terephthalate condensation polyesters, said polyesters being characterized by improved hydrolytic stability and by reduction in the free carboxyl content so as to have a carboxyl concentration of less than about 5 gram equivalents per 10 6 grams of polyester, the process comprising the steps of adding an end capping reagent in an amount of about 5 to 170 gram moles per 10 6 grams of polyester, wherein the end capping reagent is selected from the group consisting of N-epoxyalkylimides of dicarboxylic acids, long chain aliphatic epoxides, ethylene carbonate, diazomethane, monoglycidyl ethers, and mixtures thereof, to particles of the said linear polyester, heating the mixture to obtain a substantially homogeneous mixture of said polyester, while subjecting said mixture to extrusion and spinning for a residence time of about 5 to 10 minutes to produce monofilaments of said linear polyester of reduced free carboxyl content of less than about 5 gram equivalents per 10 6 grams of polyester.
Claim 3
Dependent Claim 14 words
A process according to claim 1 wherein a catalyst is added to the mixture.
Claim 4
Dependent Claim 14 words
A process according to claim 1 wherein the end capping reagent is an N-epoxyalkylimide.
Claim 5
Dependent Claim 17 words
A process according to claim 1 wherein the end capping reagent is a long chain aliphatic epoxide.
Claim 6
Dependent Claim 14 words
A process according to claim 1 wherein the end capping reagent is ethylene carbonate.
Claim 7
Dependent Claim 13 words
A process according to claim 1 wherein the end capping reagent is diazomethane.
Claim 8
Dependent Claim 16 words
A process according to claim 1 wherein the end capping reagent is a monofunctional glycidyl ether.

References Cited (Backward Citations)

US2465319A Cited
US2863854A Cited
US3050533A Cited
US3051212A Cited
US3427287A Cited
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US4016142A Cited
US3484410A Cited
US3491066A Cited
US3627867A Cited
US3657191A Cited
US4139521A Cited
US4205158A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-02-21 1986-08-23 1987-02-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-02-21 1990-08-23 1991-02-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-02-21 1994-08-23 1995-02-22 $7700.00 Window Closed / Lapsed

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