US4624982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of temporarily inhibiting the swellability of water swellable clays and compositions
Assignee: Amcol International Corp
•
Filing: 1985-04-05
•
Granted: 1986-11-25
•
Expires: 2005-04-05
Abstract
Abstract A method of temporarily inhibiting the swelling capacity of a water-swellable clay composition in contact with water includes mixing with a water-swellable clay a water soluble anionic polymer having a weight average molecular weight of about 2,000 to about 150,000 and water. The water soluble anionic polymers temporarily inhibit the swelling capacity of the water-swellable clays to decrease the viscosity of the clay slurry for transport, such as by pumping to a further treatment station such as a drier station. Also disclosed are the clay-water-anionic polymer compositions. The water soluble anionic polymers having a weight average molecular weight in the range of 2,000 to 150,000 temporarily will inhibit the swelling of a water-swellable clay so that the clay solids content of the slurry can be approximately doubled for treatment. The temporary swell-inhibiting properties of the relatively low molecular weight anionic polymers permit treatment and transportation of a clay slurry having a relatively low viscosity so that the clay solids content of the slurry can be substantially increased for primary treatment and then for transport to a secondary treatment station, such as a drier.
Inventors
- 👤 William Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:40
CPC Classifications
C; C04; C04B; C04B40/00; C04B40/0028; C04B40/0039; C01; C01B; C01B33/00; C01B33/20; C01B33/36; C01B33/38; C01B33/40; C04B14/00; C04B14/02; C04B14/04; C04B14/10; C04B14/104
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
75 words
A method of temporarily inhibiting the swelling of a water-swellable clay in contact with water comprising mixing with said water-swellable clay and water an anionic polymer having a weight average molecular weight of about 2,000 to about 150,000 to reduce the viscosity of the clay mixture, and thereafter treating the polymer to return the water swelling characteristics to the clay and to reduce the weight average molecular weight of the polymer to less than 2000.
Claim 2
Independent Claim
75 words
A method of temporarily inhibiting the swelling of a water-swellable clay in contact with water comprising mixing with said water-swellable clay and water an anionic polymer having a weight average molecular weight of about 2,000 to about 150,000 to reduce the viscosity of the clay mixture, and thereafter treating the polymer to return the water swelling characteristics to the clay and to reduce the weight average molecular weight of the polymer to less than 2000.
Claim 3
Dependent Claim
24 words
The method of claim 1 wherein the weight average molecular weight of the anionic polymer is about 2,000 to about 100,000 prior to treatment.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein the anionic polymer is a carboxy acid polymer.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein the anionic polymer is a polymer or copolymer containing acrylic acid or a derivative of acrylic acid.
Claim 6
Independent Claim
113 words
A method of processing a water-swellable clay slurry to temporarily inhibit the swelling of the clay to reduce the viscosity of the clay slurry for transport of the clay slurry and thereafter treating the slurry to substantially lessen the clay swelling inhibition, comprising: mixing a water-swellable clay, water and an anionic polymer having a weight average molecular weight less than 150,000 to form a slurry including an inhibited, water-swellable clay; and thereafter treating the slurry to reduce the molecular weight of the anionic polymer to a weight average molecular weight less than 2000 to substantially decrease the swell inhibiting effect of the anionic polymer thereby permitting the clay to substantially increase its swell.
Claim 7
Independent Claim
113 words
A method of processing a water-swellable clay slurry to temporarily inhibit the swelling of the clay to reduce the viscosity of the clay slurry for transport of the clay slurry and thereafter treating the slurry to substantially lessen the clay swelling inhibition, comprising: mixing a water-swellable clay, water and an anionic polymer having a weight average molecular weight less than 150,000 to form a slurry including an inhibited, water-swellable clay; and thereafter treating the slurry to reduce the molecular weight of the anionic polymer to a weight average molecular weight less than 2000 to substantially decrease the swell inhibiting effect of the anionic polymer thereby permitting the clay to substantially increase its swell.
Claim 8
Dependent Claim
25 words
The method of claim 5 wherein the concentration of anionic polymer is 0.005% to 0.5% by weight based on the dry weight of water-swellable clay.
Claim 9
Dependent Claim
36 words
The method of claim 6 wherein the water swellable clay is included in an amount of greater than 5 to 15% by weight based on the total weight of water-swellable clay and water in the slurry.
Claim 10
Dependent Claim
14 words
The method of claim 5 wherein the anionic polymer is a carboxy acid polymer.
Claim 11
Dependent Claim
23 words
The method of claim 8 wherein the anionic polymer is a polymer or copolymer containing acrylic acid or a derivative of acrylic acid.
Claim 12
Dependent Claim
35 words
The method of claim 8 wherein the anionic polymer is a polymer including carboxy acid, carboxy acid salt or carboxy acid anhydride substituents and ionize in water to provide a plurality of negatively charged sites.
Claim 13
Dependent Claim
21 words
The method of claim 10 wherein the anionic polymer is a copolymer including a dicarboxylic acid anhydride or a derivative thereof.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein said treatment to increase the swell properties of the clay comprises drying the clay slurry.
Claim 15
Dependent Claim
43 words
The method of claim 12 wherein the clay slurry is heated to a temperature of at least about 200° F. during drying of the clay slurry so that the dried clay is essentially no longer inhibited from swelling upon further contact with water.
Claim 16
Dependent Claim
21 words
The method of claim 1 wherein the clay slurry is heated to a temperature of 210° to 300° F. during drying.
Claim 17
Dependent Claim
21 words
The method of claim 5 wherein said treatment to increase the swell properties of the clay comprises drying the clay slurry.
Claim 18
Dependent Claim
42 words
The method of claim 15 wherein the clay slurry is heated to a temperature of at least about 200° F. during drying of the clay slurry so that the dried clay is no longer inhibited from swelling upon further contact with water.
Claim 19
Dependent Claim
21 words
The method of claim 16 wherein the clay slurry is heated to a temperature of 210° to 300° F. during drying.
References Cited (Backward Citations)
CA734551A
Cited
US3764530A
Cited
US4087365A
Cited
US3986365A
Cited
US3985659A
Cited
US4084382A
Cited
US4316833A
Cited
US4279547A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |