US4613542A
Expired / Lapsed
US
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Method of impregnating a water-penetrable article with a swell-inhibited water swellable clay slurry
Assignee: Amcol International Corp
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Filing: 1985-08-16
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Granted: 1986-09-23
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Expires: 2005-08-16
Abstract
Abstract A method of impregnating a water-penetrable article with a clay slurry includes temporarily inhibiting the swellability of the clay to unexpectedly increase the clay content and decrease the viscosity of the slurry to achieve a higher clay content in a clay-impregnated, water-penetrable article. The swelling capacity of a water-swellable clay composition in contact with water is temporarily inhibited for greater impregnation of the clay into the fibrous article by 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 to achieve a higher clay content or more efficient and faster clay impregnation into a water-penetrable, e.g. fibrous, article. 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 impregnation. The temporary swell-inhibiting properties of the relatively low molecular weight anionic polymers permit impregnation of a clay slurry having a relatively low viscosity so that the clay solids content of the slurry can be substantially increased for impregnation. Upon breakdown of the polymers to a weight average molecular weight below about 2,000, such as by heating above about 200° F., the clay reverts to its original properties.
Inventors
- 👤 William Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:59
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B28/00; C04B28/003; C04B41/45; C04B41/50; C04B41/5025; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/91; Y10; Y10T; Y10T442/00; Y10T442/20; Y10T442/2484
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
51 words
A method of impregnating a water-penetrable article with a water slurry of a water-swellable clay comprising contacting a surface of the water-penetrable article with the clay slurry wherein the slurry includes water, a water-swellable clay and an anionic polymer having a weight average molecular weight of about 2,000 to about 150,000.
Claim 2
Independent Claim
51 words
A method of impregnating a water-penetrable article with a water slurry of a water-swellable clay comprising contacting a surface of the water-penetrable article with the clay slurry wherein the slurry includes water, a water-swellable clay and an anionic polymer having a weight average molecular weight of about 2,000 to about 150,000.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the weight average molecular weight of the anionic polymer is about 2,000 to about 100,000.
Claim 4
Dependent Claim
31 words
The method of claim 1 further including reducing the molecular weight of the anionic polymer to a weight average molecular weight below 2,000 to permit the water-swellable clay to substantially swell.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein the anionic polymer is a carboxy acid polymer.
Claim 6
Dependent Claim
23 words
The method of claim 4 wherein the anionic polymer is a polymer or copolymer containing acrylic acid or a derivative of acrylic acid.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein the concentration of anionic polymer is 0.005% to 0.5% by weight based on the dry weight of water-swellable clay in the slurry.
Claim 8
Dependent Claim
31 words
The method of claim 1 wherein the water-penetrable article is impregnated by contacting the slurry on one surface of the article and subjecting an opposite side of the article to vacuum.
Claim 9
Dependent Claim
16 words
The method of claim 1 wherein the water-penetrable article comprises a mineral wool based insulating body.
Claim 10
Dependent Claim
17 words
The method of claim 1 wherein the water-penetrable article comprises a man-made consolidated board including cellulosic fibers.
Claim 11
Dependent Claim
39 words
The method of claim 1 wherein the water-penetrable article comprises a mat of fibers, including cellulosic fibers, not yet consolidated and including hot-pressing the impregnated mat to consolidate the mat and lower the molecular weight of the anionic polymer.
Claim 12
Dependent Claim
66 words
The method of claim 1 wherein the water-penetrable article comprises a relatively lightweight water-laid or air-laid cellulosic fibrous article including a binder to adhere said cellulosic fibers together, and wherein the article is disposed in a vacuum chamber above a slurry-penetrable support member; the slurry is fed onto the article, and vacuum is drawn from below the article to suck the slurry completely through the article.
Claim 13
Dependent Claim
20 words
The method of claim 11 including recirculating the slurry sucked through the board back above the board for impregnation thereof.
Claim 14
Dependent Claim
53 words
The method of claim 1 wherein the water-penetrable article comprises a tubular article and wherein the tubular article is impregnated by disposing a longitudinal central aperture of the tubular article around a perforated tube and drawing vacuum through the tube while contacting an outer surface of the tubular article with said clay slurry.
Claim 15
Dependent Claim
35 words
The method of claim 1 including drying the impregnated article at a temperature of at least 200° F. to lower the molecular weight of the anionic polymer impregnated into the article with the clay slurry.
Claim 16
Dependent Claim
9 words
The article manufactured by the method of claim 1.
Claim 17
Independent Claim
95 words
A method of impregnating a water-penetrable article with a water-swellable clay slurry, 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; impregnating the water-penetrable article with said slurry; and thereafter treating the impregnated article to reduce the molecular weight of the anionic polymer to substantially decrease the swell inhibiting effect of the anionic polymer thereby permitting the impregnated water-swellable clay to substantially increase its swell in the article when the article is thereafter contacted with water.
Claim 18
Independent Claim
95 words
A method of impregnating a water-penetrable article with a water-swellable clay slurry, 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; impregnating the water-penetrable article with said slurry; and thereafter treating the impregnated article to reduce the molecular weight of the anionic polymer to substantially decrease the swell inhibiting effect of the anionic polymer thereby permitting the impregnated water-swellable clay to substantially increase its swell in the article when the article is thereafter contacted with water.
Claim 19
Dependent Claim
28 words
The method of claim 16 wherein the concentration of anionic polymer is 0.005% to 0.5% by weight based on the dry weight of water-swellable clay in the slurry.
Claim 20
Dependent Claim
38 words
The method of claim 17 wherein the water swellable clay is included in an amount of greater than 5% and up to 20% by weight based on the total weight of water-swellable clay and water in the slurry.
Claim 21
Dependent Claim
14 words
The method of claim 16 wherein the anionic polymer is a carboxy acid polymer.
Claim 22
Dependent Claim
23 words
The method of claim 19 wherein the anionic polymer is a polymer or copolymer containing acrylic acid or a derivative of acrylic acid.
Claim 23
Dependent Claim
35 words
The method of claim 19 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 24
Dependent Claim
21 words
The method of claim 21 wherein the anionic polymer is a copolymer including a dicarboxylic acid anhydride or a derivative thereof.
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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) | 1989-09-22 | 1990-03-24 | 1990-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-22 | 1994-03-24 | 1994-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-22 | 1998-03-24 | 1998-09-23 | $7700.00 | Window Closed / Lapsed |