Patent US4219640A successfully refreshed from Google Patents.
US4219640A
Expired / Lapsed
US
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Polymers of vinyl chloride having low vinyl chloride monomer content, and method of making same
Assignee: CNA Holdings LLC
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Filing: 1977-09-22
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Granted: 1980-08-26
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Expires: 1997-09-22
Abstract
Abstract Dry particulate vinyl chloride homopolymer and copolymers, and dry particulate compositions containing major proportions of these polymers, having 2 parts or less per million of vinyl chloride monomer are provided. The vinyl chloride monomer can be so low as to be undetectable. The reduction in monomer content is achieved by subjecting the dry polymer particles to elevated temperature, agitation, and subatmospheric pressure.
Inventors
- 👤 Michael F. Saggese
- 👤 Fred V. Owens
- 👤 Barbara Fila
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:48
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/001; C08F6/005
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
225 words
A process for reducing the vinyl chloride monomer content of dry particulate homopolymers of vinyl chloride or copolymers of vinyl chloride and at least one other monomer copolymerizable therewith, that consists of a. subjecting said dry particulate homopolymers or copolymers that contain up to about 15,000 parts by weight of vinyl chloride monomer per million parts per weight of polymer, in admixture with from 0 to about 10 parts by weight per 100 parts by weight of polymer of at least one heat stabilizer, from 0 to about 20 parts by weight per 100 parts by weight of polymer of an impact modifier, from 0 to about 5 parts by weight per 100 parts by weight of polymer of a processing aid, and from 0 to about 1 part by weight per 100 parts by weight of polymer of a lubricant, to vigorous agitation in an apparatus having an attrition and shearing action and thereby elevating the temperature of said particulate homopolymers or copolymers, said elevated temperature being lower than the fusion temperature of said homopolymers or copolymers, and b. subjecting said particulate homopolymers or copolymers, while at said elevated temperature, to subatmospheric pressure in the range of from about 10 to about 26 or more inches of mercury until they contain 2 parts or less of vinyl chloride monomer per million parts of polymer.
Claim 2
Dependent Claim
225 words
A process for reducing the vinyl chloride monomer content of dry particulate homopolymers of vinyl chloride or copolymers of vinyl chloride and at least one other monomer copolymerizable therewith, that consists of a. subjecting said dry particulate homopolymers or copolymers that contain up to about 15,000 parts by weight of vinyl chloride monomer per million parts per weight of polymer, in admixture with from 0 to about 10 parts by weight per 100 parts by weight of polymer of at least one heat stabilizer, from 0 to about 20 parts by weight per 100 parts by weight of polymer of an impact modifier, from 0 to about 5 parts by weight per 100 parts by weight of polymer of a processing aid, and from 0 to about 1 part by weight per 100 parts by weight of polymer of a lubricant, to vigorous agitation in an apparatus having an attrition and shearing action and thereby elevating the temperature of said particulate homopolymers or copolymers, said elevated temperature being lower than the fusion temperature of said homopolymers or copolymers, and b. subjecting said particulate homopolymers or copolymers, while at said elevated temperature, to subatmospheric pressure in the range of from about 10 to about 26 or more inches of mercury until they contain 2 parts or less of vinyl chloride monomer per million parts of polymer.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said elevated temperature is at least about 120° C.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein dry particulate homopolymers or copolymers having a vinyl chloride monomer content of 1 part or less per million are obtained.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein dry particulate homopolymers or copolymers having a vinyl chloride monomer content undetectable by gas chromatography are obtained.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein the dry particulate homopolymer of vinyl chloride is a low molecular weight vinyl chloride homopolymer.
Claim 7
Dependent Claim
21 words
The process of claim 1 wherein the dry particulate copolymer is a low molecular weight copolymer of vinyl chloride and ethylene.
Claim 8
Dependent Claim
13 words
The process of claim 1 wherein the heat stabilizer is an organotin compound.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein the organotin compound is dibutyltin bis(isooctyl thioglycolate).
Claim 10
Dependent Claim
14 words
The process of claim 1 wherein the heat stabilizer is a calcium/zinc complex stabilizer.
Claim 11
Dependent Claim
13 words
The process of claim 1 wherein the heat stabilizer is an epoxidized oil.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-26 | 1984-02-25 | 1984-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-26 | 1988-02-25 | 1988-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-26 | 1992-02-25 | 1992-08-26 | $7700.00 | Window Closed / Lapsed |