Patent US3816151A successfully refreshed from Google Patents.
US3816151A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-destructing gels
Assignee: Hercules LLC
•
Filing: 1972-08-03
•
Granted: 1974-06-11
•
Expires: 1992-08-03
Abstract
Abstract Self-destructing polymer gels are prepared by adding to an aqueous solution of an anionic polymer a trivalent chromium compound and an oxidizer selected from either the water-soluble permanganates or persulfates. The polymer can be either an acrylamide-acrylic acid copolymer or CMC. Gelling takes place rapidly followed by decomposition of the gels over a period of several hours to several days.
Inventors
- 👤 T Podlas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:24
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/60; C09K8/62; C09K8/66; C09K8/68; C09K8/685; C08; C08K; C08K3/00; C08K3/10; C08K3/11; C09K8/58; C09K8/588; Y; Y10; Y10S; Y10S507/00; Y10S507/903; Y10S507/922; Y10S507/935; Y10S507/936
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
17 words
A method according to claim 1 wherein the polymer is a copolymer of acrylamide and sodium acrylate.
Claim 2
Dependent Claim
11 words
A method according to claim 1 wherein the polymer is carboxymethylcellulose.
Claim 3
Dependent Claim
15 words
A method according to claim 2 wherein the oxidizer is potassium permanganate or potassium persulfate.
Claim 4
Dependent Claim
14 words
A method according to claim 4 wherein the trivalent chromium salt is chrome alum.
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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |