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US4540762A
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Copolymers of sodium styrene sulfonate and sodium-N-(4-sulfophenyl)-maleimide
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1983-12-12
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Granted: 1985-09-10
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Expires: 2003-12-12
Abstract
Abstract This invention relates to a water soluble alternating copolymer having a 50 mol. % portion of a sodium-N-(4-sulfophenyl)-maleimide monomer and a 50 mol. % portion of a sulfonated styrenic comonomer. The sulfonated styrenic comonomer is characterized by the formula: ##STR1## wherein Y.sup.⊕ is a cation selected from the Groups IA, IIA, IB or IIB of the Periodic Table or an amine of the formula .sup.⊕NHR 1 R 2 where R 1 , R 2 and R 3 can be aliphatic groups of C 1 to C 12 , wherein the alternating water soluble copolymers are useful as thermally stable deflocculating agents in water based drilling muds.
Inventors
- 👤 S. Richard Turner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:39
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/24
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
A water soluble, solid alternating copolymer of about 50 mol. % sodium-N-(4-sulfophenyl)-maleimide monomer units and a metal or amine neutralized sulfonate monomer units characterized by the formula: ##STR11## wherein Y.sup.⊕ is a cation selected from Groups IA, IIA, IB or IIB of the Periodic Table or an amine of the formula: ##STR12## where R 1 , R 2 and R 3 are aliphatic groups of C 1 to C 12 or hydrogen.
Claim 2
Dependent Claim
72 words
A water soluble, solid alternating copolymer of about 50 mol. % sodium-N-(4-sulfophenyl)-maleimide monomer units and a metal or amine neutralized sulfonate monomer units characterized by the formula: ##STR11## wherein Y.sup.⊕ is a cation selected from Groups IA, IIA, IB or IIB of the Periodic Table or an amine of the formula: ##STR12## where R 1 , R 2 and R 3 are aliphatic groups of C 1 to C 12 or hydrogen.
Claim 3
Dependent Claim
16 words
A copolymer according to claim 1 wherein said sulfonate-containing monomer is a metal neutralized sulfonated styrene.
Claim 4
Dependent Claim
14 words
A copolymer according to claim 1 wherein said sulfonate-containing monomer is sodium styrene sulfonate.
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) | 1988-09-09 | 1989-03-11 | 1989-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-09 | 1993-03-11 | 1993-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-09 | 1997-03-11 | 1997-09-10 | $7700.00 | Window Closed / Lapsed |