Patent US3721659A successfully refreshed from Google Patents.
US3721659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of rubber
Assignee: NATURAL RUBBER PRODUCERS
•
Filing: 1970-11-16
•
Granted: 1973-03-20
•
Expires: 1990-11-16
Abstract
Abstract Novel urethane reaction products of aromatic nitroso compounds with isocyanates are used to improve the resistance of unsaturated rubbers to oxidative degradation by providing antioxidant groups bound to the rubber molecules. Dry rubber or rubber latex is conveniently reacted with decomposition products of the urethane during normal vulcanization.
Inventors
- 👤 M Cain
- 👤 G Knight
- 👤 K Frederick
- 👤 P Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:17
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/80; C08G18/8061; C08G18/807; C08G18/28; C08G18/67; C08G18/69; C08K; C08K5/00; C08K5/16; C08K5/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
36 words
A process as claimed in claim 1, wherein the amount of the urethane is such as to provide from 0.2 to 3.0 percent by weight of an aromatic nitroso compound on the weight of the rubber.
Claim 2
Dependent Claim
20 words
A process as claimed in claim 1, wherein X is an organic hydrocarbon group and m is 1 or 2.
Claim 3
Dependent Claim
69 words
A process as claimed in claim 1, wherein the rubber is used in the form of a latex, an amount of the urethane to provide from 0.2 to 2.0 percent by weight of an aromatic nitroso compound on the weight of the rubber is mixed with the rubber latex, and the mixture is heated at a temperature of from 60* to 130* C for from 1 to 60 minutes.
Claim 4
Dependent Claim
63 words
A process as claimed in claim 1, wherein the rubber is used dry, an amount of the urethane to provide from 0.5 to 3.0 percent by weight of an aromatic nitroso compound on the weight of the rubber is mixed with the dry rubber, and the mixture is heated at a temperature of from 100* to 250*C for from 1 to 60 minutes.
Claim 5
Dependent Claim
18 words
A process as claimed in claim 1, wherein the heating step is also used to vulcanize the rubber.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |