US3791913A
Expired / Lapsed
US
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Free flowing elastomer pellets and process for their preparation
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1971-05-17
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Granted: 1974-02-12
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Expires: 1991-05-17
Abstract
Abstract Free flowing pellets of substantially unvulcanized elastomeric polymers having a cured surface are prepared by exposing the pellets to a curing medium for said elastomer for sufficient time to allow vulcanization of the exterior portions of the pellet; i.e., so that the pellet is cured to a maximum depth of about one-tenth of the diameter of its smallest dimension.
Inventors
- 👤 Strate G Ver
- 👤 E Kresge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:33
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C08J3/24; C08J3/245; C08J2321/00; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31917; Y10T428/31924
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
29 words
The pellet of claim 1 wherein said surface is cured to a depth of not more than about one-tenth of the diameter of the smallest dimension of said pellet.
Claim 2
Dependent Claim
16 words
The pellet of claim 2 wherein the smallest dimension of said pellet is about 1 mm.
Claim 3
Dependent Claim
32 words
The pellet of claim 3 wherein the cross-link density of the cured surface is between about 0.5 X 10 5 and about 10 X 10 4 moles of cross-links per cubic centimeter.
Claim 4
Dependent Claim
49 words
A process for preparing a free-flowing, substantially unvulcanized vulcanizable unsaturated elastomer pellet of at least 0.2 mole percent unsaturation which comprises exposing said unvulcanized vulcanizable unsaturated elastomer pellet to a curing medium for said elastomer for sufficient time to allow vulcanization of only the exterior portions of said pellet.
Claim 5
Dependent Claim
36 words
The process of claim 5 wherein the exposure time is such that the pellet exterior is vulcanized to a depth of not more than about one-tenth of the diameter of the smallest dimension of said pellet.
Claim 6
Dependent Claim
58 words
The process of claim 6 wherein the substantially unvulcanized vulcanizable elastomer pellet comprises an unsaturated elastomer of at least 0.5 mole percent unsaturation and the curing medium is selected from the group consisting of SCl2, S2Cl2, Cl3CSCl compounds of the type ClS-RSCl where R is an organic molecule having from one to 10 carbon atoms, and mixtures thereof.
Claim 7
Dependent Claim
27 words
The process of claim 7 wherein the curing medium is gaseous and selected from the group consisting of SCl2 and an equilibrium mixture of SCl2 and S2Cl2.
Claim 8
Dependent Claim
44 words
The process of claim 8 wherein the exposure time for the pellet is from about 0.01 to 1 second, the partial pressure of the curing medium is from about 0.01 to about 1 atmosphere, and the pellet temperature is from about 500*F. to ambient.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |