Patent US4981471A successfully refreshed from Google Patents.
US5354801A
Expired / Lapsed
US
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Process for producing small polymer phase droplet microemulsions by multistep aqueous phase addition
Assignee: BASF Corp
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Filing: 1993-08-12
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Granted: 1994-10-11
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Expires: 2013-08-12
Abstract
Abstract A novel method for producing compositions comprising polymeric solution droplets is disclosed. The products are useful as retention aids in paper pulps, as flocculating agents for flocculating a wide variety of dispersions of suspended solids and as drive fluids for use in oil recovery.
Inventors
- 👤 Michael P. O'Toole
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:58
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
161 words
A method of preparing water-in-oil polymer microemulsions having small aqueous phase droplet sizes comprising: (a) preparing an oil phase comprising: (i) at least one hydrocarbon; and (ii) an effective amount of a surfactant or mixture of surfactants to form a microemulsion upon the addition of an aqueous phase; (b) preparing an aqueous phase comprising: (i) at least one ethylenically unsaturated monomer; (c) adding a portion of said aqueous phase (b) to said oil phase (a) to form a microemulsion and polymerizing; and (d) adding another portion of said aqueous phase (b) to the product of step (c) to form a microemulsion and polymerizing so as to form a polymer microemulsion having a polymer solids content of less than about 25% and an emulsifier to monomer ratio of less than about 0.4, wherein the aqueous polymer phase droplets produced by said method are smaller than those obtained by a method comprising a single addition of the same total amount of aqueous phase.
Claim 2
Independent Claim
161 words
A method of preparing water-in-oil polymer microemulsions having small aqueous phase droplet sizes comprising: (a) preparing an oil phase comprising: (i) at least one hydrocarbon; and (ii) an effective amount of a surfactant or mixture of surfactants to form a microemulsion upon the addition of an aqueous phase; (b) preparing an aqueous phase comprising: (i) at least one ethylenically unsaturated monomer; (c) adding a portion of said aqueous phase (b) to said oil phase (a) to form a microemulsion and polymerizing; and (d) adding another portion of said aqueous phase (b) to the product of step (c) to form a microemulsion and polymerizing so as to form a polymer microemulsion having a polymer solids content of less than about 25% and an emulsifier to monomer ratio of less than about 0.4, wherein the aqueous polymer phase droplets produced by said method are smaller than those obtained by a method comprising a single addition of the same total amount of aqueous phase.
Claim 3
Dependent Claim
16 words
A method as defined in claim 1 wherein said ethyenically unsaturated monomer comprises an anionic monomer.
Claim 4
Dependent Claim
16 words
A method as defined in claim 1 wherein said ethylenically unsaturated monomer comprises a cationic monomer.
Claim 5
Dependent Claim
16 words
A method as defined in claim 1 wherein said ethylenically unsaturated monomer comprises a non-ionic monomer.
Claim 6
Dependent Claim
17 words
A method as defined in claim 1 further comprising adding a cross-linking monomer to said aqueous phase.
Claim 7
Dependent Claim
17 words
A method as defined in claim 1 wherein said portions of said aqueous phase are substantially equal.
Claim 8
Dependent Claim
34 words
A method as defined in claim 1 wherein steps (c) and (d) comprise two or more incremental additions of portions of aqueous (b) to said oil phase (a) with polymerization after each incremental addition.
Claim 9
Dependent Claim
21 words
A method as defined in claim 7 wherein there are "n" incremental addition/polymerization stages wherein n ranges from 2 to 10.
Claim 10
Dependent Claim
17 words
A method as defined in claim 7 wherein said incremental addition/polymerization stages are performed in dropwise increments.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |