US4555556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tertiary perfluorinated compounds as rate enhancing additives in PTFE dispersion polymerization
Assignee: EIDP Inc
•
Filing: 1985-03-12
•
Granted: 1985-11-26
•
Expires: 2005-03-12
Abstract
Abstract An improvement is disclosed in a process for conducting PTFE dispersion polymerization, comprising use of tertiary perfluorinated compounds as rate enhancing additives.
Inventors
- 👤 Aleksander Beresniewicz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:32
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/18; C08F14/26
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
76 words
In a process for producing a colloidal dispersion of polytetrafluoroethylene homopolymer or copolymers of tetrafluoroethylene and ethylenically unsaturated comonomers by polymerizing tetrafluoroethylene and, optionally, ethylenically unsaturated comonomers, in an aqueous medium in the presence of a suitable initiator and a surfactant, the improvement comprising use as a rate enhancing additive of a compound of the formula ##STR5## wherein A is --OH, --COOH, --NH 2 , or --C(O)NH 2 ; and n is 0, 1 or 2.
Claim 2
Dependent Claim
76 words
In a process for producing a colloidal dispersion of polytetrafluoroethylene homopolymer or copolymers of tetrafluoroethylene and ethylenically unsaturated comonomers by polymerizing tetrafluoroethylene and, optionally, ethylenically unsaturated comonomers, in an aqueous medium in the presence of a suitable initiator and a surfactant, the improvement comprising use as a rate enhancing additive of a compound of the formula ##STR5## wherein A is --OH, --COOH, --NH 2 , or --C(O)NH 2 ; and n is 0, 1 or 2.
Claim 3
Dependent Claim
26 words
A process according to claim 1, wherein the rate enhancing additive is present at a concentration of from 0.1 to 5 percent by weight of medium.
Claim 4
Dependent Claim
24 words
A process according to claim 2, wherein the surfactant is present at a concentration of from 0.01 to 0.3 percent by weight of medium.
Claim 5
Dependent Claim
33 words
A process according to claim 3, wherein polymerization is conducted at a temperature from about 40° C. to about 120° C., and at a pressure from about 138 kPa to about 4140 kPa.
Claim 6
Dependent Claim
27 words
A process according to claim 3, wherein the rate enhancing additive is present at a concentration from about 0.2 to about 1.0 percent by weight of medium.
Claim 7
Dependent Claim
33 words
A process according to claim 5, wherein polymerization is conducted at a temperature from about 60° C. to about 90° C., and at a pressure from about 690 kPa to about 2070 kPa.
Claim 8
Dependent Claim
10 words
A process according to claim 1, wherein A is --OH.
Claim 9
Dependent Claim
10 words
A process according to claim 7, wherein n is 1.
Claim 10
Dependent Claim
10 words
A process according to claim 7, wherein n is 0.
References Cited (Backward Citations)
US2559629A
Cited
US2559752A
Cited
US3391099A
Cited
US3704285A
Cited
US4025709A
Cited
US4384092A
Cited
US4380618A
Cited
US4482685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-11-25 | 1989-05-27 | 1989-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-25 | 1993-05-27 | 1993-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-25 | 1997-05-27 | 1997-11-26 | $7700.00 | Window Closed / Lapsed |