US4125696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization process using di-t-butyl diperoxycarbonate as a finishing catalyst
Assignee: Arkema Inc
•
Filing: 1977-01-06
•
Granted: 1978-11-14
•
Expires: 1997-01-06
Abstract
Abstract A process for the free-radical polymerization of a vinyl monomer, including vinyl aromatic monomer, at least two distinct, progressively higher polymerization temperatures, each between the temperatures of from about 50° C and 130° C, in the presence of at least two free-radical initiators, one of which, used in relatively minor proportions, is di-t-butyl diperoxycarbonate and the other, used in relatively major proportions, has a ten hour half-life temperature below 90° C. The distinct temperatures for polymerization may occur as separate parts of a polymerization in which the temperature of the system continually increases.
Inventors
- 👤 Vasanth R. Kamath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:47
CPC Classifications
C; C08; C08F; C08F4/00; C08F4/28; C08F4/32; C08F4/38
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
125 words
A process for the free-radical polymerization of a vinyl monomer, including vinyl aromatic monomer, comprising polymerizing said monomer at at least two distinct, progressively higher polymerization temperatures, each between the temperatures of from about 50° C. to 130° C., in the presence of at least two free-radical initiators, one of which, used in relatively minor proportions as a finishing catalyst, is a di-t-butyl piperoxycarbonate and the other, has a ten hour half-life temperature below 90° C., wherein the same solvent is used for measuring the half life of all initiators, wherein the time to produce polymer without more than 0.1 weight percent residual monomer can be reduced by as much as 20% of the time required if the di-t-butyl diperoxycarbonate finishing initiator were not present.
Claim 2
Dependent Claim
125 words
A process for the free-radical polymerization of a vinyl monomer, including vinyl aromatic monomer, comprising polymerizing said monomer at at least two distinct, progressively higher polymerization temperatures, each between the temperatures of from about 50° C. to 130° C., in the presence of at least two free-radical initiators, one of which, used in relatively minor proportions as a finishing catalyst, is a di-t-butyl piperoxycarbonate and the other, has a ten hour half-life temperature below 90° C., wherein the same solvent is used for measuring the half life of all initiators, wherein the time to produce polymer without more than 0.1 weight percent residual monomer can be reduced by as much as 20% of the time required if the di-t-butyl diperoxycarbonate finishing initiator were not present.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the polymerization process is conducted isothermally at two distinct temperatures.
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein the distinct temperatures occur as separate parts of the polymerization in which the temperature of the system continually increases.
Claim 5
Dependent Claim
20 words
The process of claim 1 wherein the initiator having the ten hour half-life temperature below 90° C. is benzoyl peroxide.
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein the vinyl monomer is styrene.
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) | 1981-11-13 | 1982-05-15 | 1982-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-13 | 1986-05-15 | 1986-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-13 | 1990-05-15 | 1990-11-14 | $7700.00 | Window Closed / Lapsed |