US3847635A
Expired / Lapsed
US
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Thixotropic cementitious composition and process
Assignee: United States Gypsum Co
•
Filing: 1973-07-18
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Granted: 1974-11-12
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Expires: 1993-07-18
Abstract
Abstract Cementitious mixtures of alpha calcium sulfate hemihydrate, portland cement and a dispersing agent are rendered thixotropic by the inclusion of small amounts of crystallized magnesium sulfate.
Inventors
- 👤 R Lange
- 👤 W Kobeski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:12
CPC Classifications
C; C04; C04B; C04B22/00; C04B22/08; C04B22/14; C04B22/142
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
40 words
A PROCESS FOR IMPARTING THIXOTROPIC CHARACTERISTICS TO DILATANT CEMENTITIOUS MASSES OF ALPHA CALCIUM SULFATE HEMIHYDRATE-PORTLAND CEMENT AND MINOR AMOUNTS OF A DISPERSING AGENT COMPRISING THE STEP OF ADDING TO THE CEMENTITIOUS MASS A MINOR AMOUNT BY WEIGHT OF MAGNESIUM SULFATE.
Claim 2
Dependent Claim
40 words
A PROCESS FOR IMPARTING THIXOTROPIC CHARACTERISTICS TO DILATANT CEMENTITIOUS MASSES OF ALPHA CALCIUM SULFATE HEMIHYDRATE-PORTLAND CEMENT AND MINOR AMOUNTS OF A DISPERSING AGENT COMPRISING THE STEP OF ADDING TO THE CEMENTITIOUS MASS A MINOR AMOUNT BY WEIGHT OF MAGNESIUM SULFATE.
Claim 3
Dependent Claim
14 words
The process of claim 1 in which the magnesium sulfate is magnesium sulfate heptahydrate.
Claim 4
Dependent Claim
17 words
The process of claim 1 in whichh the magnesium sulfate is added to a dry cementitious mass.
Claim 5
Dependent Claim
29 words
The process of claim 1 in which the cementitious mass is mixed with water to form an aqueous slurry; and the magnesium sulfate is added to the aqueous slurry.
Claim 6
Dependent Claim
35 words
The process of claim 1 in which the cementitious mass is mixed with water to form a pumpable aqueous slurry; the slurry is pumped; and the magnesium sulfate is added to the slurry being pumped.
Claim 7
Dependent Claim
46 words
The process of claim 1 in which the cementitious mass contains by weight, on a dry weight basis, about 49-94 percent alpha calcium sulfate hemihydrate; about 49-5 percent portland cement; and about 0.5-0.8 percent dispersing agent; and about 0.2-0.5 percent magnesium sulfate heptahydrate is added thereto.
Claim 8
Dependent Claim
29 words
A thixotropic, settable, plastic mass comprising an aqueous slurry of alpha calcium sulfate hemihydrate; portland cement; a minor amount of dispersing agent; and a minor amount of magnesium sulfate.
Claim 9
Dependent Claim
29 words
A thixotropic, settable, plastic mass comprising an aqueous slurry of alpha calcium sulfate hemihydrate; portland cement; a minor amount of dispersing agent; and a minor amount of magnesium sulfate.
Claim 10
Dependent Claim
18 words
A thixotropic, settable, plastic mass according to claim 7 in which the magnesium sulfate is magnesium sulfate heptahydrate.
Claim 11
Dependent Claim
30 words
A thixotropic, settable, plastic mass according to claim 7 containing by weight on a dry weight basis about 0.5-0.8 percent of dispersing agent and about 0.2-0.5 percent of magnesium sulfate.
Claim 12
Dependent Claim
32 words
A thixotropic, settable, plastic mass according to claim 8 containing by weight on a dry weight basis about 49-94 percent of alpha calcium sulfate hemihydrate and about 49-5 percent of portland cement.
Claim 13
Dependent Claim
44 words
A dry mixture capable of setting on the addition of water and exhibiting thixotropic characteristics on the addition of water comprising alpha calcium sulfate hemihydrate; portland cement; a minor amount by weight of dispersing agent; and a minor amount by weight of magnesium sulfate.
Claim 14
Dependent Claim
44 words
A dry mixture capable of setting on the addition of water and exhibiting thixotropic characteristics on the addition of water comprising alpha calcium sulfate hemihydrate; portland cement; a minor amount by weight of dispersing agent; and a minor amount by weight of magnesium sulfate.
Claim 15
Dependent Claim
38 words
A dry mixture according to claim 11 containing by weight about 49-94 percent of alpha calcium sulfate hemihydrate; about 49-5 percent of portland cement; about 0.5-0.8 percent of dispersing agent; and about 0.2-0.5 percent of magnesium sulfate heptahydrate.
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) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |