Patent US4655842A successfully refreshed from Google Patents.
US4655842A
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Vermiculite dispersions and method of preparing same
Assignee: WR Grace and Co Conn
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Filing: 1985-08-12
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Granted: 1987-04-07
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Expires: 2005-08-12
Abstract
Abstract Stable vermiculite dispersions which are substantially free of settling and a method of preparing same are provided. The dispersions are obtained by treating the vermiculite platelets of which the dispersion is comprised with citrate anion. The citrate anion functions as a swelling agent for the vermiculite and enhances the rate and extent of swelling in an aqueous medium. The swollen vermiculite is delaminated by shearing to provide the inventive dispersions, which comprise a suspension of the delaminated platelets and citrate anion.
Inventors
- 👤 Chia-Chih Ou
- 👤 Julie C. Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:49
CPC Classifications
C; C04; C04B; C04B30/00; C04B14/00; C04B14/02; C04B14/04; C04B14/20; C04B14/206; C04B14/208
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
85 words
A process for preparing aqueous vermiculite dispersions comprising the steps of: treating vermiculite crystals with citrate anion and a cation which promotes swelling of said crystals in a direction normal to the main cleavage plane of said crystals during immersion in water subsequent to said treatment; immersing the treated crystals in water; permitting the immersed crystals to swell; and subjecting the resultant swollen crystals while immersed in water to a shearing force to delaminate the vermiculite crystal and form a suspension of delaminated vermiculite platelets.
Claim 2
Dependent Claim
85 words
A process for preparing aqueous vermiculite dispersions comprising the steps of: treating vermiculite crystals with citrate anion and a cation which promotes swelling of said crystals in a direction normal to the main cleavage plane of said crystals during immersion in water subsequent to said treatment; immersing the treated crystals in water; permitting the immersed crystals to swell; and subjecting the resultant swollen crystals while immersed in water to a shearing force to delaminate the vermiculite crystal and form a suspension of delaminated vermiculite platelets.
Claim 3
Dependent Claim
30 words
A process of claim 1 wherein said vermiculite is treated by immersion in an aqueous treatment bath containing a solubilized citrate salt and a solubilized non-citrate salt of said cation.
Claim 4
Dependent Claim
28 words
A process of claim 1 wherein said vermiculite is treated by immersion in an aqueous treatment bath comprising citric acid and a solubilized non-citrate salt of said cation.
Claim 5
Dependent Claim
13 words
A process of claim 3 wherein said non-citrate salt is a lithium salt.
Claim 6
Dependent Claim
38 words
A process of claim 1 wherein said cation is selected form the group consisting of N-alkylammonium cations having 3 to 6 carbon atoms inclusive in each alkyl group, the cationic form of an amino acid, and lithium cation.
Claim 7
Dependent Claim
11 words
A process of claim 1 wherein said cation is lithium cation.
Claim 8
Dependent Claim
25 words
A process of claim 1 wherein said vermiculite is treated by immersion in an aqueous treatment bath containing a solubilized citrate salt of said cation.
Claim 9
Dependent Claim
12 words
A process of claim 7 wherein said citrate salt is lithium citrate.
Claim 10
Dependent Claim
18 words
A process of claim 1 wherein said vermiculite is treated sequentially with said citrate anion and said cation.
Claim 11
Dependent Claim
34 words
A process of claim 1 wherein said vermiculite is treated by immersion in a treatment bath comprising said citrate anion in a concentration in the range of about 0.02N. up to a saturation concentration.
Claim 12
Dependent Claim
21 words
A process of claim 10 wherein the concentration of said citrate anion is in the range of about 2N. to 4N.
Claim 13
Dependent Claim
23 words
A process of claim 3 wherein the concentration of citric acid in said bath is in the range of about 0.02N. to 0.2N.
Claim 14
Dependent Claim
24 words
A process of claim 7 wherein the concentration of said citrate salt is in the range of about 0.5N. up to a saturation concentration.
Claim 15
Dependent Claim
21 words
A process of claim 13 wherein the concentration of said citrate salt is in the range of about 2N. to 4N.
Claim 16
Dependent Claim
33 words
A process of claim 1 wherein the weight concentration of vermiculite platelets in the dispersion formed by shearing said swollen vermiculite is less than about 15% based on the weight of the dispersion.
Claim 17
Dependent Claim
21 words
A process of claim 15 wherein the weight concentration of vermiculite platelets is in the range of about 4% to 12%.
Claim 18
Dependent Claim
10 words
A vermiculite dispersion prepared by the process of claim 1.
Claim 19
Dependent Claim
10 words
An aqueous dispersion comprising delaminated vermiculite platelets and citrate anion.
Claim 20
Dependent Claim
10 words
An aqueous dispersion comprising delaminated vermiculite platelets and citrate anion.
Claim 21
Dependent Claim
25 words
A dispersion of claim 18 wherein the weight concentration of said vermiculite platelets is less than about 15%, based on the weight of said dispersion.
Claim 22
Dependent Claim
29 words
A dispersion of claim 19 wherein the weight concentration of said vermiculite platelets is in the range of about 4% to 12%, based on the weight of said dispersion.
Claim 23
Dependent Claim
30 words
A process for preparing a stable dispersion of vermiculite platelets which comprises contacting said platelets with citrate anion to substantially prevent the settling out of said platelets from said dispersion.
Claim 24
Dependent Claim
30 words
A process for preparing a stable dispersion of vermiculite platelets which comprises contacting said platelets with citrate anion to substantially prevent the settling out of said platelets from said dispersion.
Claim 25
Dependent Claim
67 words
A process for increasing the rate and extent of swelling of vermiculite ore particles comprising the steps of: treating vermiculite ore particles with citrate anion and a cation which promotes swelling of said particles in a direction normal to the main cleavage plane of said particles during immersion in water subsequent to said treatment; immersing the treated particles in water; and permitting the immersed particles to swell.
Claim 26
Dependent Claim
67 words
A process for increasing the rate and extent of swelling of vermiculite ore particles comprising the steps of: treating vermiculite ore particles with citrate anion and a cation which promotes swelling of said particles in a direction normal to the main cleavage plane of said particles during immersion in water subsequent to said treatment; immersing the treated particles in water; and permitting the immersed particles to swell.
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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) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |