Patent US4277586A successfully refreshed from Google Patents.
US4277586A
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Process for preparing a propylene-tetrafluoroethylene copolymer
Assignee: AGC Inc
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Filing: 1977-01-27
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Granted: 1981-07-07
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Expires: 1997-01-27
Abstract
Abstract Propylene and tetrafluoroethylene are copolymerized at the low temperature of 0 DEG -50 DEG C. in an aqueous medium in the presence of a specific redox catalyst system. The specific redox catalyst system comprises (1) a water soluble inorganic persulfate, (2) a water soluble thiosulfate or bisulfite and (3) a water soluble iron salt, and preferably further comprises a reducing sugar and a water soluble pyrophosphate. The propylene-tetrafluoroethylene copolymer having high molecular weight and low Mooney viscosity can be prepared at high copolymerization reaction rates.
Inventors
- 👤 Hiroshi Ukihashi
- 👤 Masaaki Yamabe
- 👤 Hiroaki Kojima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:57
CPC Classifications
C; C08; C08F; C08F214/00; C08F214/18; C08F214/26; C08F214/265; C08F210/00; C08F210/04; C08F210/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
In a process for the preparation of a stable dispersion of a propylene and tetrafluoroethylene copolymer of molecular weight 80,000-300,000 and a Mooney viscosity (ML 1+10 , 100° C.) of 40-150 in which propylene and tetrafluoroethylene are copolymerized while dispersed in an aqueous medium, the improvement which comprises: copolymerizing said propylene and tetrafluoroethylene at 10°-45° C. in the presence of a catalyst system comprising (1) a water soluble inorganic persulfate, (2) a water soluble thiosulfate or bisulfite and (3) a water soluble iron salt, the molar ratio of said water soluble inorganic persulfate/water soluble thiosulfate or bisulfite/water soluble iron salt being 0.1-2.0/1.0/0.005-0.5.
Claim 2
Dependent Claim
102 words
In a process for the preparation of a stable dispersion of a propylene and tetrafluoroethylene copolymer of molecular weight 80,000-300,000 and a Mooney viscosity (ML 1+10 , 100° C.) of 40-150 in which propylene and tetrafluoroethylene are copolymerized while dispersed in an aqueous medium, the improvement which comprises: copolymerizing said propylene and tetrafluoroethylene at 10°-45° C. in the presence of a catalyst system comprising (1) a water soluble inorganic persulfate, (2) a water soluble thiosulfate or bisulfite and (3) a water soluble iron salt, the molar ratio of said water soluble inorganic persulfate/water soluble thiosulfate or bisulfite/water soluble iron salt being 0.1-2.0/1.0/0.005-0.5.
Claim 3
Dependent Claim
20 words
The process according to claim 1, wherein the molar ratio of tetrafluoroethylene to propylene in the reaction system is 90/10-70/30.
Claim 4
Dependent Claim
19 words
The process according to claim 1, wherein a comonomer is added to the mixture gas of propylene and tetrafluoroethylene.
Claim 5
Dependent Claim
18 words
The process according to claim 1, wherein 0.001-5 wt % catalyst system is added to the aqueous medium.
Claim 6
Dependent Claim
19 words
The process according to claim 1, wherein said iron salt is combined with a pyrophosphate and a reducing sugar.
Claim 7
Dependent Claim
22 words
The process according to claim 1, wherein the copolymerization reaction is performed under a pressure of lower than 100 kg/cm 2 (gauge).
Claim 8
Dependent Claim
15 words
The process according to claim 1, wherein the copolymerization reaction is performed at pH 7.0-11.0.
Claim 9
Dependent Claim
21 words
The process according to claim 1, wherein the copolymerization reaction is performed in the presence of a water miscible organic solvent.
Claim 10
Dependent Claim
45 words
The process according to claim 5, wherein the molar ratio of pyrophosphate/persulfate is 0.1-20/1 and the molar ratio of the reducing sugar/persulfate is 0.1-20/1, and the pyrophosphate and the reducing sugar are combined in a solution of the iron salt before mixing with the persulfate.
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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) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |