Patent US531723A successfully refreshed from Google Patents.
Patent US3687923A successfully refreshed from Google Patents.
US3687923A
Expired / Lapsed
US
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Polymerization of ethylenic monomers and products thereof
Assignee: Produits Chimiques Pechiney Saint Gobain
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Filing: 1966-03-17
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Granted: 1972-08-29
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Expires: 1986-03-17
Abstract
Abstract An improved process for the production of fine spherical grains of substantially uniform size of an ethylenic polymer and in particular vinyl chloride, which comprises polymerizing a portion of the monomer with turbulent agitation to form seeds, and adding a larger portion of liquid monomer and continuing the polymerization with mild agitation.
Inventors
- 👤 Jean Claude Thomas
- 👤 Salomon Soussan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:48
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/02; C08F14/00; C08F14/02; C08F14/04; C08F14/06; Y; Y10; Y10S; Y10S526/00; Y10S526/909
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
13 words
A method according to claim 1 in which the monomer comprises vinyl chloride.
Claim 2
Dependent Claim
21 words
A method according to claim 1 in which the monomer includes vinyl chloride and at least one other compatible, copolymerizable, monomer.
Claim 3
Dependent Claim
36 words
A method according to claim 1 in which the first stage of polymerization is by contact with a catalyst of short half life and the second stage in contact with a catalyst of longer half life.
Claim 4
Dependent Claim
34 words
A method according to claim 2 in which the quantity of monomer employed in the stage of turbulent agitation is about one-third to one-half of the total quantity of monomer engaged in the process.
Claim 5
Dependent Claim
39 words
A method according to claim 5 which includes the step of establishing a degree of turbulent agitation as a function of the number of particles of polymer which are to be formed in the turbulEnt stage of the process.
Claim 6
Dependent Claim
149 words
A batch method of polymerizing ethylenic monomers, the polymers of which are insoluble in their monomers, into small spherical particles of substantially uniform size, in mass, which comprises subjecting a minor portion of the batch of such monomers with catalyst having a short half life to conditions of temperature and pressure, favorable to polymerization until 7 to 15 percent of the monomers of said minor portion have been polymerized, while maintaining the monomers in a state of turbulence, thereby forming small particles of polymer, and enlarging the particles of polymer by mixing the partly polymerized minor portion with the remaining portion of said batch of monomer and a catalyst having a longer half life than said first catalyst and continuing the polymerization under conditions of temperature and pressure favorable to polymerization, until more than half of said batch has been polymerized, with mild agitation to form spherical dense particles.
Claim 7
Independent Claim
87 words
A method of polymerizing vinyl chloride in mass which comprises forming minute polymer seeds from liquid monomer, by turbulent agitation in the presence of a catalyst, mixing the minute polymerseed and the liquid monomer in which they were formed with a body of liquid monomer of at least equal bulk and additional catalyst, and enlarging the seeds into fine grain spherical particles by subjecting the seeds and the mixture to mild agitation under conditions of temperature, pressure and in the presence of said catalyst favorable to polymerization.
Claim 8
Dependent Claim
18 words
The method of claim 8 in which the polymer seeds are in the mother liquor of their formation.
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) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |