Patent US3856767A successfully refreshed from Google Patents.
US3856767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerisation process
Assignee: Individual
•
Filing: 1972-04-18
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Granted: 1974-12-24
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Expires: 1992-04-18
Abstract
Abstract To obtain high or low crystalline pvc vinyl chloride is polymerised under conventional conditions in the presence of a finely divided seed polymer having an order factor above 16 or below 10. The seed materials can only be made by polymerising vinyl chloride under non-conventional conditions.
Inventors
- 👤 A Sturt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:41
CPC Classifications
C; C08; C08F; C08F259/00; C08F259/02; C08F259/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
149 words
A PROCESS FOR THE PRODUCTION OF A VINYL CHLORIDE POLYMER CONTAINING A MAJOR PROPORTION OF VINYL CHLORIDE WHICH COMPRISES ADDING A SEED VINYL CHLORIDE POLYMER OR COPOLYMER CONTAINING A MAJOR PROPORTION OF VINYL CHLORIDE IN A FINELY DRIVIDED FROM HAVING AN AVERAGE PARTICLE SIZE OF LESS THAN 200 &M AND HAVING AN ORDER FACTOR ABOVE 16 OR BELOW 10, SAID DISPERSED THEREIN TO PRODUCE A VINYL CHLORIDE CONTAINING POLYIN THIS CLAIM, TO VINYL CHLORIDE MONOMER AND POLYMERISING AT A TEMPERATURE IN THE RANGE OF 30*-80*C THE VINYL CHLORIDE MONOMER IN SUSPENSION OR IN MASS USING A FREE RADICAL MONOMER IN SUSPENSION OR IN MASS USING A FREE RADICAL DISPERSED THEREIN TO PRODUCE A VINYL CHLORIDE CONTAINING POLYMER HAVING AN ORDER FACTOR ABOVE 16 OR BELOW 10, RESPECTIVELY, THE WEIGHT RATION OF SAID POLYMER OR COPOLYMER TO VINYL CHLORIDE CONTAINING MONOMER BEING IN THE RANGE OF 0.1 :99.9 TO 50:50.
Claim 2
Dependent Claim
17 words
A process according to claim 1 where the seed vinyl chloride polymer is prepared by mass polymerisation.
Claim 3
Dependent Claim
17 words
A process according to claim 1 where the seed vinyl chloride polymer is prepared by suspension polymerisation.
Claim 4
Dependent Claim
17 words
A process according to claim 1 where the seed vinyl chloride polymer is prepared by emulsion polymerisation.
Claim 5
Dependent Claim
22 words
A process according to claim 1 where the free radical polymerisation is operated at a temperature in the range 45* to 70*C.
Claim 6
Dependent Claim
18 words
A process according to claim 1 where the weight ratio lies in the range of 0.5:99.5 to 20:80.
Claim 7
Dependent Claim
17 words
A process according to claim 6 where the weight ratio lies in the range 5:95 to 10:90.
References Cited (Backward Citations)
GB847676A
Cited
US3067186A
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GB931629A
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US3332918A
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US3380946A
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US3536675A
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US3523111A
Cited
US3520867A
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US3683051A
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US3652525A
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US3725375A
Cited
US3687917A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |