US3956249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of polyvinyl chloride of low vinyl chloride monomer content by treatment of wet polyvinyl chloride
Assignee: Occidental Chemical Corp
•
Filing: 1974-06-24
•
Granted: 1976-05-11
•
Expires: 1994-06-24
Abstract
Abstract Vinyl chloride is removed from wet cakes that comprise a vinyl chloride polymer, vinyl chloride, and water by contacting the wet cakes with steam, preferably at atmospheric pressure and at a temperature in the range of 100 DEG to 125 DEG C.
Inventors
- 👤 Donald Goodman
- 👤 Robert S. Miller
- 👤 Robert J. Stanaback
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:01
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/001; C08F6/005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
77 words
In suspension and emulsion polymerization processes for the production of vinyl chloride polymers selected from the group consisting of polyvinyl chloride and copolymers of vinyl chloride and at least one monomer copolymerizable therewith wherein a wet cake consisting essentially of said vinyl chloride polymer, water, and vinyl chloride is formed and vinyl chloride is separated from said wet cake, the improvement that comprises removing vinyl chloride from the wet cake by contacting the wet cake with steam.
Claim 2
Dependent Claim
77 words
In suspension and emulsion polymerization processes for the production of vinyl chloride polymers selected from the group consisting of polyvinyl chloride and copolymers of vinyl chloride and at least one monomer copolymerizable therewith wherein a wet cake consisting essentially of said vinyl chloride polymer, water, and vinyl chloride is formed and vinyl chloride is separated from said wet cake, the improvement that comprises removing vinyl chloride from the wet cake by contacting the wet cake with steam.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein the wet cake is contacted with steam at atmospheric pressure and at a temperature in the range of about 100°C. to 125°C.
Claim 4
Dependent Claim
24 words
The process of claim 1 wherein the wet cake is contacted with steam until it contains not more than 10 ppm of vinyl chloride.
Claim 5
Dependent Claim
41 words
The process of claim 3 wherein the wet cake is contacted with steam until it contains an amount of vinyl chloride that is undetectable by a gas chromatograph that is capable of detecting as little as 0.1 ppm of vinyl chloride.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein the vinyl chloride polymer in the wet cake is polyvinyl chloride.
Claim 7
Dependent Claim
29 words
The process of claim 1 wherein the vinyl chloride polymer in the wet cake is a copolymer containing vinyl chloride and up to 30% by weight of vinyl acetate.
Claim 8
Dependent Claim
93 words
In suspension and emulsion polymerization processes for the production of vinyl chloride polymers selected from the group consisting of polyvinyl chloride and copolymers of vinyl chloride and at least one monomer copolymerizable therewith wherein a wet cake is formed, said wet cake containing vinyl chloride particles that are from 1 micron to 500 microns in diameter, vinyl chloride, and from 1% to 50% by weight of water, and vinyl chloride is separated from said wet cake, the improvement comprising removing vinyl chloride from the wet cake by contacting the wet cake with steam.
Claim 9
Dependent Claim
93 words
In suspension and emulsion polymerization processes for the production of vinyl chloride polymers selected from the group consisting of polyvinyl chloride and copolymers of vinyl chloride and at least one monomer copolymerizable therewith wherein a wet cake is formed, said wet cake containing vinyl chloride particles that are from 1 micron to 500 microns in diameter, vinyl chloride, and from 1% to 50% by weight of water, and vinyl chloride is separated from said wet cake, the improvement comprising removing vinyl chloride from the wet cake by contacting the wet cake with steam.
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) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |