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US3720637A
Expired / Lapsed
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Olefin-maleic anhydride crosslinked terpolymers
Assignee: Chevron USA Inc
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Filing: 1971-03-29
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Granted: 1973-03-13
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Expires: 1991-03-29
Abstract
Abstract Crosslinked terpolymers of isobutene-maleic anhydride and divinylbenzene and their alkali metal, amide ammonium, amide amine, ammonium and amine salts and aqueous dispersions thereof.
Inventors
- 👤 R Bacskai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:44
CPC Classifications
C; C08; C08F; C08F22/00; C08F22/04; C08F10/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
46 words
Crosslinked terpolymers of substantially equimolar portions of isobutene and maleic anhydride with divinylbenzene in a proportion in the range of from about 0.1 mol percent to about 5 mol percent of the terpolymer and the amide-ammonium salts thereof, said terpolymers being substantially insoluble in dimethyl formamide.
Claim 2
Dependent Claim
46 words
Crosslinked terpolymers of substantially equimolar portions of isobutene and maleic anhydride with divinylbenzene in a proportion in the range of from about 0.1 mol percent to about 5 mol percent of the terpolymer and the amide-ammonium salts thereof, said terpolymers being substantially insoluble in dimethyl formamide.
Claim 3
Dependent Claim
12 words
The crosslinked terpolymers of isobutene, maleic anhydride and divinylbenzene of claim 1.
Claim 4
Dependent Claim
9 words
The amide-ammonium salts of crosslinked terpolymers of claim 2.
Claim 5
Dependent Claim
28 words
An aqueous dispersion consisting essentially of a major proportion of water and a minor proportion sufficient to thicken said water of a compound of claim 1 dispersed therein.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |