US4373956A
Expired / Lapsed
US
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Additive for hydraulic cement mixes
Assignee: Sandoz AG
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Filing: 1981-09-14
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Granted: 1983-02-15
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Expires: 2001-09-14
Abstract
Abstract A hydraulic cement mix including hydraulic cement, aggregate, sufficient water to effect hydraulic setting of the cement, and an additive comprising a mixture of an alkali or alkaline earth or ammonium salt of thiocyanic acid, such as sodium, potassium, lithium, calcium or magnesium thiocyanate, and an alkanolamine, such as triethanolamine, the additive being present in an amount sufficient to increase rate of hardening, and the compressive strength of the hardened mix. Generally, the additive is present in a total amount of up to about 2.5% by weight based upon the weight of the cement, usually in an amount of between about 0.05% and about 2.55% by weight based upon the weight of the cement, preferably in an amount in the range of about 0.4% to about 0.6% by weight.
Inventors
- 👤 Philip A. Rosskopf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:34
CPC Classifications
C; C04; C04B; C04B22/00; C04B22/08; C04B28/00; C04B28/02; C04B28/04; C04B24/00; C04B24/12; C04B24/121
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
113 words
A hydraulic cement mix comprising a hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, sufficient water to effect hydraulic setting of the cement, and an additive comprising a mixture of an alkali and/or alkaline earth or ammonium salt of thiocyanic acid in an amount of between 0.05% and 2.5% by weight based upon the weight of the cement and an alkanolamine in an amount of between 0.001% and 0.05% by weight based upon the weight of the cement, whereby the rate of hardening of said cement mix is accelerated and the early compressive strength of the hardened mix is increased.
Claim 2
Dependent Claim
113 words
A hydraulic cement mix comprising a hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, sufficient water to effect hydraulic setting of the cement, and an additive comprising a mixture of an alkali and/or alkaline earth or ammonium salt of thiocyanic acid in an amount of between 0.05% and 2.5% by weight based upon the weight of the cement and an alkanolamine in an amount of between 0.001% and 0.05% by weight based upon the weight of the cement, whereby the rate of hardening of said cement mix is accelerated and the early compressive strength of the hardened mix is increased.
Claim 3
Dependent Claim
16 words
A hydraulic cement mix in accordance with claim 1, wherein said hydraulic cement comprises portland cement.
Claim 4
Dependent Claim
55 words
A hydraulic cement mix in accordance with claim 1, wherein said salt of thiocyanate is present in an amount of between 0.5% and 1.5% by weight based upon the weight of the cement and said alkanolamine is present in an amount of between 0.01% and 0.04% by weight based upon the weight of the cement.
Claim 5
Dependent Claim
18 words
A hydraulic cement mix in accordance with claim 1, wherein said salt of thiocyanic acid is sodium thiocyanate.
Claim 6
Dependent Claim
18 words
A hydraulic cement mix in accordance with claim 1, wherein said salt of thiocyanic acid is potassium thiocyanate.
Claim 7
Dependent Claim
18 words
A hydraulic cement mix in accordance with claim 1, wherein said salt of thiocyanic acid is calcium thiocyanate.
Claim 8
Dependent Claim
18 words
A hydraulic cement mix in accordance with claim 1, wherein said salt of thiocyanic acid is magnesium thiocyanate.
Claim 9
Dependent Claim
24 words
A hydraulic cement mix in accordance with claim 1, wherein said aggregate is present in an amount of from 20% to 80% by weight.
Claim 10
Dependent Claim
14 words
A hydraulic cement mix in accordance with claim 1, wherein said alkanolamine comprises triethanolamine.
Claim 11
Dependent Claim
120 words
A process for accelerating the hardening of hydraulic cement mixes which include hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, and sufficient water to effect hydraulic setting of the cement, comprising incorporating an additive comprising a mixture of an alkali, alkaline earth or ammonium salt of thiocyanic acid in an amount of between 0.05% and 2.5% by weight based upon the weight of the cement and an alkanolamine in an amount of between 0.001% and 0.05% by weight based upon the weight of the cement, whereby the rate of hardening of said cement mix is accelerated and the early compressive strength of the hardened mix is increased.
Claim 12
Dependent Claim
120 words
A process for accelerating the hardening of hydraulic cement mixes which include hydraulic cement, aggregate in an amount of up to 80% by weight based upon the total weight of said cement mix, and sufficient water to effect hydraulic setting of the cement, comprising incorporating an additive comprising a mixture of an alkali, alkaline earth or ammonium salt of thiocyanic acid in an amount of between 0.05% and 2.5% by weight based upon the weight of the cement and an alkanolamine in an amount of between 0.001% and 0.05% by weight based upon the weight of the cement, whereby the rate of hardening of said cement mix is accelerated and the early compressive strength of the hardened mix is increased.
Claim 13
Dependent Claim
14 words
A process in accordance with claim 10, wherein said hydraulic cement comprises portland cement.
Claim 14
Dependent Claim
53 words
A process in accordance with claim 10, wherein said salt of thiocyanate is present in an amount of between 0.5% and 1.5% by weight based upon the weight of the cement and said alkanolamine is present in an amount of between 0.01% and 0.04% by weight based upon the weight of the cement.
Claim 15
Dependent Claim
16 words
A process in accordance with claim 10, wherein said salt of thiocyanic acid is sodium thiocyanate.
Claim 16
Dependent Claim
16 words
A process in accordance with claim 10, wherein said salt of thiocyanic acid is potassium thiocyanate.
Claim 17
Dependent Claim
16 words
A process in accordance with claim 10, wherein said salt of thiocyanic acid is calcium thiocyanate.
Claim 18
Dependent Claim
16 words
A process in accordance with claim 10, wherein said salt of thiocyanic acid is magnesium thiocyanate.
Claim 19
Dependent Claim
22 words
A process in accordance with claim 10, wherein said aggregate is present in an amount of from 20% to 80% by weight.
Claim 20
Dependent Claim
12 words
A process in accordance with claim 10, wherein said alkanolamine comprises triethanolamine.
References Cited (Backward Citations)
US3782991A
Cited
US4298392A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-14 | 1986-08-16 | 1987-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-14 | 1990-08-16 | 1991-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-14 | 1994-08-16 | 1995-02-15 | $7700.00 | Window Closed / Lapsed |