Patent US4015065A successfully refreshed from Google Patents.
US4015065A
Expired / Lapsed
US
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Treatment of vinyl halide polymers
Assignee: BP PLC
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Filing: 1975-05-05
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Granted: 1977-03-29
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Expires: 1995-05-05
Abstract
Abstract Vinyl halide monomer content of vinyl halide polymer is reduced by subjecting the polymer to radio frequency dielectric heating in the presence of added polymerization initiator.
Inventors
- 👤 Anthony John Park
- 👤 Alan Charles Sturt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:02
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/006; C08F259/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
57 words
A process for treating vinyl halide polymer containing residual vinyl halide produced by the polymerization of monomeric material consisting of vinyl halide and 0 to 30% by weight of total monomeric material of comonomers copolymerizable with vinyl halide which comprises subjecting said polymer to radio frequency dielectric heating in the presence of added free radical polymerization initiator.
Claim 2
Dependent Claim
57 words
A process for treating vinyl halide polymer containing residual vinyl halide produced by the polymerization of monomeric material consisting of vinyl halide and 0 to 30% by weight of total monomeric material of comonomers copolymerizable with vinyl halide which comprises subjecting said polymer to radio frequency dielectric heating in the presence of added free radical polymerization initiator.
Claim 3
Dependent Claim
52 words
A process according to claim 1 wherein the vinyl halide polymer is polyvinyl chloride, the vinyl halide it contains is vinyl chloride, and the polymer is produced from a monomeric material consisting of vinyl chloride and from 0 to 20% by weight of total monomeric material of comonomer copolymerisable with vinyl chloride.
Claim 4
Dependent Claim
23 words
A process according to claim 1 wherein the amount of residual vinyl halide monomer does not exceed 3% by weight of the polymer.
Claim 5
Dependent Claim
21 words
A process according to claim 1 wherein the polymer contains up to 20% by water based on weight of dry polymer.
Claim 6
Dependent Claim
27 words
A process according to claim 1 wherein the polymer is subjected to radio frequency dielectric heating for a time in the range 0.1 second to 100 minutes.
Claim 7
Dependent Claim
27 words
A process according to claim 5 wherein the polymer is subjected to radio frequency dielectric heating for a time in the range 1 second to 40 minutes.
Claim 8
Dependent Claim
24 words
A process according to claim 6 wherein the polymer is subjected to radio frequency dielectric heating for a time of at least one minute.
Claim 9
Dependent Claim
37 words
A process according to claim 6 wherein the polymer is subjected to radio frequency dielectric heating for a time sufficient to raise the temperature of the polymer to a temperature in the range 70° to 120° C.
Claim 10
Dependent Claim
18 words
A process according to claim 1 wherein the polymer is subjected to low frequency dielectric heating between electrodes.
Claim 11
Dependent Claim
18 words
A process according to claim 9 wherein the frequency used is in the range 1 to 150 MHz.
Claim 12
Dependent Claim
14 words
A process according to claim 1 wherein the polymer is subjected to microwave radiation.
Claim 13
Dependent Claim
19 words
A process according to claim 11 wherein the microwave radiation is at a frequency of 600 to 50,000 MHz.
Claim 14
Dependent Claim
17 words
A process according to claim 12 wherein the frequency is in the range 900 to 30,000 MHz.
Claim 15
Dependent Claim
19 words
A process according to claim 1 wherein initiator is brought into contact with the polymer after polymerisation is ended.
Claim 16
Dependent Claim
30 words
A process according to claim 14 wherein from 0.01% to 1% by weight of initiator, based on weight of dry polymer is added to the polymer after polymerisation has ended.
Claim 17
Dependent Claim
32 words
The process according to claim 1 wherein the minimum quantity of initiator present at the beginning of the radio frequency dielectric heating of suspension polymer is 0.1% by weight of dry polymer.
Claim 18
Dependent Claim
32 words
A process according to claim 2 wherein the polymer subjected to radio frequency dielectric heating is vinyl chloride polymer in the form of beads recovered from suspension polymerization and containing residual monomer.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-28 | 1980-09-27 | 1981-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-28 | 1984-09-27 | 1985-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-28 | 1988-09-27 | 1989-03-29 | $7700.00 | Window Closed / Lapsed |