US4708997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suspending agent for the suspension polymerization of water-soluble monomers
Assignee: Dow Chemical Co
•
Filing: 1986-03-14
•
Granted: 1987-11-24
•
Expires: 2006-03-14
Abstract
Abstract A suspending agent useful in a water-in-oil suspension polymerization process comprises a fumed silica particulate having a hydrophobic character and a hydrophobic polymer. The suspending agent is useful in providing uniformly sized aqueous fluid absorbent polymer beads.
Inventors
- 👤 Frederick W. Stanley, Jr.
- 👤 Jack C. Lamphere
- 👤 Yohannes Chonde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:20
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
A process for the suspension polymerization of water-soluble monomers comprising: (1) providing an aqueous phase comprising water and at least one water-soluble monomer, (2) providing an oil phase comprising an inert hydrophobic liquid and a suspending agent comprising (a) hydrophobic fumed silicon dioxide, and (b) a copolymer of acrylic acid and lauryl methacrylate, and (3) contacting the aqueous phase and the oil phase under conditions such that a water-in-oil suspension of polymer comprising polymerized water-soluble monomer is provided.
Claim 2
Dependent Claim
78 words
A process for the suspension polymerization of water-soluble monomers comprising: (1) providing an aqueous phase comprising water and at least one water-soluble monomer, (2) providing an oil phase comprising an inert hydrophobic liquid and a suspending agent comprising (a) hydrophobic fumed silicon dioxide, and (b) a copolymer of acrylic acid and lauryl methacrylate, and (3) contacting the aqueous phase and the oil phase under conditions such that a water-in-oil suspension of polymer comprising polymerized water-soluble monomer is provided.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said water-soluble monomers are polymerized in the presence of a crosslinking agent.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein said crosslinking agent is provided in said aqueous phase.
Claim 5
Dependent Claim
15 words
The process of claim 2 wherein said crosslinking agent is provided in said oil phase.
Claim 6
Dependent Claim
19 words
The process of claim 2 wherein said crosslinking agent is provided in said aqueous phase and said oil phase.
Claim 7
Dependent Claim
30 words
The process of claim 1 wherein the amount of suspending agent ranges from about 0.05 to about 10 weight percent relative to the amount of water-soluble monomer which is polymerized.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein said aqueous phase is dispesed in said oil phase.
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) | 1990-11-23 | 1991-05-25 | 1991-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-23 | 1995-05-25 | 1995-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-23 | 1999-05-25 | 1999-11-24 | $7700.00 | Window Closed / Lapsed |