US4244835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of dispersing alpha alumina monohydrate
Assignee: WR Grace and Co Conn
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Filing: 1978-12-14
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Granted: 1981-01-13
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Expires: 1998-12-14
Abstract
Abstract A method of forming an aqueous dispersion of alpha alumina monohydrate by subjecting a mixture of water and alpha alumina monohydrate to high shear rates. The process is further enhanced by having the mixture contain a small amount of a base selected from a water soluble alkali metal hydroxide, carbonate or oxide. The invention is also directed to a water dispersable alpha alumina monohydrate composition comprising solid particulate alpha alumina monohydrate having from 1 to 5% by weight of an alkali metal oxide, hydroxide or carbonate or ammonium hydroxide substantially uniformly mixed therewith.
Inventors
- 👤 Jacob Block
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:49
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
82 words
A method of forming an aqueous pseudoplastic dispersion of α-Al 2 O 3 .H 2 O comprising forming a mixture of water, a water soluble base and solid, particulate α-Al 2 O 3 .H 2 O, subjecting the mixture to high shear rates of greater than about 10,000 reciprocal seconds and for a time of from about 1 to about 60 minutes which is sufficient to cause a substantially complete aqueous pseudoplastic dispersion of said α-Al 2 O 3 .H 2 O.
Claim 2
Independent Claim
82 words
A method of forming an aqueous pseudoplastic dispersion of α-Al 2 O 3 .H 2 O comprising forming a mixture of water, a water soluble base and solid, particulate α-Al 2 O 3 .H 2 O, subjecting the mixture to high shear rates of greater than about 10,000 reciprocal seconds and for a time of from about 1 to about 60 minutes which is sufficient to cause a substantially complete aqueous pseudoplastic dispersion of said α-Al 2 O 3 .H 2 O.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the αAl 2 O 3 .H 2 O is present in from 1 to 40 percent of the aqueous mixture.
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein the aqueous mixture contains a base from about 0.1 to 5 weight percent based on the weight of the alumina present.
Claim 5
Dependent Claim
25 words
The process of claim 3 wherein the base is selected from the group consisting of an alkali metal oxide, hydroxide and carbonate, and ammonium hydroxide.
Claim 6
Dependent Claim
13 words
The process of claim 4 wherein the base is an alkali metal hydroxide.
Claim 7
Dependent Claim
11 words
The process of claim 5 wherein the alkali metal is sodium.
Claim 8
Independent Claim
67 words
The method of forming an aqueous system which exhibits pseudoplastic properties comprising contacting solid, particulate. Al 2 O 3 .H 2 O and a solid, particulate, water soluble base with water to form an aqueous mixture thereof; subjecting the aqueous mixture to high shear rates for a period of time sufficient to form a stable, dispersion and adjusting the pH of the dispersion to greater than 8.
Claim 9
Independent Claim
67 words
The method of forming an aqueous system which exhibits pseudoplastic properties comprising contacting solid, particulate. Al 2 O 3 .H 2 O and a solid, particulate, water soluble base with water to form an aqueous mixture thereof; subjecting the aqueous mixture to high shear rates for a period of time sufficient to form a stable, dispersion and adjusting the pH of the dispersion to greater than 8.
Claim 10
Dependent Claim
15 words
The method of claim 7 wherein the base is an alkali metal oxide or hydroxide.
Claim 11
Dependent Claim
17 words
The method of claim 7 wherein the high shear rate is at least about 10,000 reciprocal seconds.
Claim 12
Dependent Claim
13 words
The method of claim 8 wherein the base is sodium hydroxide or oxide.
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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |