US3979366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vinyl chloride suspension polymerization
Assignee: VISTA POLYMERS Inc A DE CRP AND WHOLLY-OWNED SUBSIDIARY OF VISTA CHEMICAL Co
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Filing: 1975-06-12
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Granted: 1976-09-07
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Expires: 1995-06-12
Abstract
Abstract An improved process for the suspension polymerization of vinyl chloride homopolymers is accomplished by the addition of small amount of chain extending agent to the polymerization formula allowing the polymerization to be run at a higher temperature thus making better use of the reactor's heat removal capability. More efficient use of initiator is also accomplished while producing polyvinyl chloride having the desired molecular weight dependent physical properties. The process also allows a faster rate of polymerization.
Inventors
- 👤 Peter A. Schwab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:58
CPC Classifications
C; C08; C08F; C08F14/00; C08F14/02; C08F14/04; C08F14/06
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
60 words
An improved method for the production polyvinyl chloride homopolymer by suspension polymerization of vinyl chloride monomer, the improvement comprising carrying out the entire polymerization in the presence of about 300 to 500 parts per million of a chain-extending agent selected from the group consisting of diallyl maleate, triallyl isocyanurate, and diallyl phthalate while using elevated temperatures and reduced polymerization times.
Claim 2
Dependent Claim
60 words
An improved method for the production polyvinyl chloride homopolymer by suspension polymerization of vinyl chloride monomer, the improvement comprising carrying out the entire polymerization in the presence of about 300 to 500 parts per million of a chain-extending agent selected from the group consisting of diallyl maleate, triallyl isocyanurate, and diallyl phthalate while using elevated temperatures and reduced polymerization times.
Claim 3
Dependent Claim
22 words
A method as described in claim 1 wherein the reaction is carried out at a temperature of from about 120° to 160°F.
Claim 4
Dependent Claim
16 words
A method as described in claim 1 wherein the polymerization time is about 4 1/2 hours.
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) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |