US3767436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cement set accelerator
Assignee: Sandoz AG
•
Filing: 1971-09-09
•
Granted: 1973-10-23
•
Expires: 1991-09-09
Abstract
Abstract The rate of hardening of a portland cement mix is accelerated by the addition of a low molecular weight, water-soluble hydroxylated adduct formed by reacting melamine and an aldehyde. The adduct is employed in an amount within the range of from about 0.01% to about 1.00%, preferably from about 0.2% to about 0.8% by weight of cement. The water content of the cement mix for a given consistency tends to be lowered by the incorporation of the adduct, providing an additional advantage from the practice of the invention. The adduct may be employed as a concentrated solution in water and may be used in combination with known set accelerating agents and with set retarding agents where reduction in water content is desired without appreciable change in the rate of set of the cement mix.
Inventors
- 👤 R Peppler
- 👤 P Rosskopf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:01
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04; C04B24/00; C04B24/24; C04B24/28; C04B24/30; C04B24/305
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
13 words
The hydraulic cement mix of claim 1 in which said aldehyde comprises formaldehyde.
Claim 2
Dependent Claim
32 words
The hydraulic cement mix of claim 2 in which said additive is present in an amount within the range of from about 0.2 percent to about 0.8 percent by weight of cement.
Claim 3
Dependent Claim
61 words
The hydraulic cement mix of claim 1 and including therein a second additive comprising a concrete set retarder in an amount such that the effect of said combination of additives on the rate of hardening is less than that resulting from the use of the first additive alone, the water content of the mix for a given consistency being advantageously limited.
Claim 4
Dependent Claim
20 words
The hydraulic cement mix of claim 4 in which said set retarder comprises calcium lignosulfonate and said aldehyde comprises formaldehyde.
Claim 5
Dependent Claim
38 words
The hydraulic cement mix of claim 1 and including therein a second additive comprising an additional set accelerating agent in an amount such as to effect a further acceleration in the rate of hardening of said cement mix.
Claim 6
Dependent Claim
15 words
The hydraulic cement mix of claim 6 in which said second additive comprises water-soluble formates.
Claim 7
Dependent Claim
20 words
The hydraulic cement mix of claim 7 in which said water-soluble formates comprise sodium formate and said aldehyde comprises formaldehyde.
Claim 8
Dependent Claim
32 words
The hydraulic cement mix of claim 6 in which said additive is present in an amount within the range of from about 0.2 percent to about 0.8 percent by weight of cement.
Claim 9
Dependent Claim
92 words
A process for accelerating the hardening of hydraulic cement mixes comprising incorporating an additive in a hydraulic cement mix of portland cement, aggregate and sufficient water to effect hydraulic setting of the cement, said additive comprising a water-soluble melamine-aldehyde condensate, said additive being incorporated in an amount within the range of from about 0.01 percent to about 1.00 percent by weight of cement, whereby the rate of hardening of the cement mix is accelerated and the amount of water required for a given consistency is limited without undesired toxic or corrosive effects.
Claim 10
Dependent Claim
11 words
The process of claim 10 in which said aldehyde comprises formaldehyde.
Claim 11
Dependent Claim
30 words
The process of claim 11 in which said additive is present in an amount within the range of from about 0.2 percent to about 0.8 percent by weight of cement.
Claim 12
Dependent Claim
68 words
The process of claim 10 and including the incorporating of a second additive in said cement mix, said second additive comprising a concrete set retarder in an amount such that the effect of said combination of additives on the rate of hardening is less than that resulting from the use of the first additive alone, the water content of the mix for a given consistency being advantageously limited.
Claim 13
Dependent Claim
18 words
The process of claim 13 in which said set retarder comprises calcium lignosulfonate and said aldehyde comprises formaldehyde.
Claim 14
Dependent Claim
35 words
The process of claim 14 in which said first additive is incorporated in the cement mix in an amount within the range of from about 0.2 percent to about 0.8 percent by weight of cement.
Claim 15
Dependent Claim
45 words
The process of claim 10 and including the incorporating of a second additive in said cement mix, said second additive comprising an additional set accelerating agent in an amount such as to effect a further acceleration in the rate of hardening of said cement mix.
Claim 16
Dependent Claim
13 words
The process of claim 16 in which said second additive comprises water-soluble formates.
Claim 17
Dependent Claim
17 words
The process of claim 17 in which said water-soluble formates comprise sodium formate, said aldehyde comprises formaldehyde.
Claim 18
Dependent Claim
31 words
The process of claim 18 in which said first additive is incorporated in an amount within the range of from about 0.2 percent to about 0.8 percent by weight of cement.
Claim 19
Dependent Claim
18 words
The process of claim 11 in which said additive is incorporated in said mix in dry powder form.
Claim 20
Dependent Claim
18 words
The process of claim 11 in which said additive is incorporated in said mix as a water mixture.
Claim 21
Dependent Claim
29 words
The process of claim 21 in which said additive is incorporated as a concentrated water solution having an additive concentration of about 80 percent by weight of said solution.
Claim 22
Dependent Claim
19 words
The process of claim 15 in which said first additive is incorporated in said mix in dry powder form.
Claim 23
Dependent Claim
19 words
The process of claim 15 in which said first additive is incorporated in said mix as a water mixture.
Claim 24
Dependent Claim
30 words
The process of claim 15 in which said first additive is incorporated as a concentrated water solution having an additive concentration of about 80 percent by weight of said solution.
Claim 25
Dependent Claim
19 words
The process of claim 19 in which said first additive is incorporated in said mix in dry powder form.
Claim 26
Dependent Claim
19 words
The process of claim 19 in which said first additive is incorporated in said mix as a water mixture.
Claim 27
Dependent Claim
30 words
The process of claim 19 in which said first additive is incorporated as a concentrated water solution having an additive concentration of about 80 percent by weight of said solution.
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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) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |