US4197399A
Expired / Lapsed
US
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Process for removing residual vinyl chloride from vinyl chloride polymers in aqueous dispersion
Assignee: Solvay SA
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Filing: 1975-07-15
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Granted: 1980-04-08
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Expires: 1995-07-15
Abstract
Abstract Process for removing the residual vinyl chloride monomer present after polymerisation in vinyl chloride polymers in the form of an aqueous dispersion which is heated to a temperature at least equal to the glass transition temperature of the polymer and subjected to stripping by an inert fluid while being maintained at a temperature at least equal to the glass transition temperature of the polymer.
Inventors
- 👤 Stephane Noel
- 👤 Jean Golstein
- 👤 Guillaume Coppens
- 👤 Jean-Claude Davoine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:47
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/14; C08F6/16
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
101 words
In a process for removing the residual vinyl chloride monomer present after polymerization in vinyl chloride polymer by heating the polymer to a temperature at least equal to the glass transition temperature of the polymer, and subjecting the polymer to stripping by an inert fluid while maintaining the polymer at a temperature at least equal to the glass transition temperature of the polymer, the improvement comprising, prior to separating the polymer from an aqueous dispersion which is formed during the polymerization, heating and subjecting to stripping the vinyl chloride polymer in the form of said aqueous dispersion obtained directly from polymerization.
Claim 2
Dependent Claim
101 words
In a process for removing the residual vinyl chloride monomer present after polymerization in vinyl chloride polymer by heating the polymer to a temperature at least equal to the glass transition temperature of the polymer, and subjecting the polymer to stripping by an inert fluid while maintaining the polymer at a temperature at least equal to the glass transition temperature of the polymer, the improvement comprising, prior to separating the polymer from an aqueous dispersion which is formed during the polymerization, heating and subjecting to stripping the vinyl chloride polymer in the form of said aqueous dispersion obtained directly from polymerization.
Claim 3
Dependent Claim
18 words
Process as in claim 1, wherein the aqueous polymer dispersion is heated to a temperature below 140° C.
Claim 4
Dependent Claim
18 words
Process as in claim 1, wherein the aqueous polymer dispersion is heated to a temperature below 120° C.
Claim 5
Dependent Claim
13 words
Process as in claim 1, wherein polymer dispersion is degassed before being heated.
Claim 6
Dependent Claim
19 words
Process as in claim 4, wherein the aqueous polymer dispersion is degassed at a temperature below the polymerisation temperature.
Claim 7
Dependent Claim
11 words
Process as in claim 1, wherein the inert fluid is steam.
Claim 8
Dependent Claim
21 words
Process as in claim 6 wherein steam stripping is carried out by means of steam generated by boiling the aqueous dispersion.
Claim 9
Dependent Claim
28 words
Process as in claim 1, wherein when the aqueous dispersion has been subjected to stripping by the inert fluid it is caused to boil by reducing the pressure.
Claim 10
Dependent Claim
54 words
Process in claim 8, wherein the aqueous dispersion is allowed to cool after stripping at the temperature at least equal to the glass transition temperature of the polymer; and the pressure is progressively reduced, as the temperature of the aqueous dispersion decreases, so as to maintain boiling without the application of calories from outside.
Claim 11
Dependent Claim
29 words
Process as in claim 8, wherein the boiling is terminated when the temperature of the aqueous dispersion has reached a value below the glass transition temperature of the polymer.
Claim 12
Dependent Claim
27 words
Process as in claim 8, wherein the boiling is terminated when the temperature of the aqueous dispersion has reached a value of between 50° and 80° C.
Claim 13
Dependent Claim
14 words
Process as in claim 6, wherein the steam leaving the aqueous dispersion is condensed.
Claim 14
Dependent Claim
33 words
Process as in claim 12, wherein the stripping is conducted in a vessel and the steam is condensed in a condenser connected to the vessel and to a vacuum pump directly connected therewith.
Claim 15
Dependent Claim
16 words
Process as in claim 13, wherein part of the condensed water is recycled to the vessel.
Claim 16
Dependent Claim
19 words
Process as in claim 1, wherein the stripping with an inert fluid is carried out in the polymerisation reactor.
Claim 17
Dependent Claim
23 words
Process as in claim 1, wherein the stripping with an inert fluid is carried out in a vessel other than the polymerization reactor.
Claim 18
Dependent Claim
18 words
Process as in claim 15, wherein the stripping fluid is introduced at the bottom of the polymerisation reactor.
Claim 19
Dependent Claim
20 words
Process as in claim 1, wherein residual monomer is removed from vinyl chloride polymers obtained by polymerisation in aqueous suspension.
Claim 20
Dependent Claim
15 words
Process as in claim 1, wherein vinyl chloride is removed from a vinyl chloride homopolymer.
Claim 21
Dependent Claim
29 words
Process as in claim 9 wherein the boiling is terminated when the temperature of the aqueous dispersion has reached a value below the glass transition temperature of the polymer.
Claim 22
Dependent Claim
27 words
Process as in claim 9 wherein the boiling is terminated when the temperature of the aqueous dispersion has reached a value of between 50° and 80° C.
Claim 23
Dependent Claim
14 words
Process as in claim 8 wherein the steam leaving the aqueous dispersion is condensed.
Claim 24
Dependent Claim
33 words
Process as in claim 22, wherein the stripping is conducted in a vessel and the steam is condensed in a condenser connected to the vessel and to a vacuum pump directly connected therewith.
Claim 25
Dependent Claim
16 words
Process as in claim 23, wherein part of the condensed water is recycled to the vessel.
Claim 26
Dependent Claim
17 words
Process as in claim 16 wherein the stripping fluid is introduced at the bottom of the vessel.
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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |