US3785839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portland cement and additives therefor
Assignee: Sandoz AG
•
Filing: 1971-09-09
•
Granted: 1974-01-15
•
Expires: 1991-09-09
Abstract
Abstract The rate of hardening of a portland cement mix is accelerated by the addition of a monomeric, water-soluble hydroxylated adduct formed by reacting a urea and an aldehyde, said adduct being employed in an amount within the range of from about 0.01 percent to about 1.00 percent, advantageously about 0.2 percent to about 0.8 percent, 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, conveniently monomethylolurea and dimethylolurea, while avoiding toxic and corrosive effects normally associated with aldehyde-type set accelerators. The adducts may be employed in concentrated amounts in water and may be used in combination with known set accelerating agents. The adducts may also be employed in combination with set retarders 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
2026-11-04 08:59
CPC Classifications
C; C04; C04B; C04B28/00; C04B28/02; C04B28/04; C04B24/00; C04B24/12; C04B24/126; C04B2103/00; C04B2103/10; C04B2103/12
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
13 words
The hydraulic cement mix of claim 1 in which the additive comprises monomethylolurea.
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
13 words
The hydraulic cement mix of claim 1 in which said additive comprises dimethylolurea.
Claim 4
Dependent Claim
32 words
The hydraulic cement mix of claim 4 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 5
Dependent Claim
62 words
The hydraulic cement mix of claim 1 and including therein a second additive comprising a concrete set retarding agent 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 6
Dependent Claim
31 words
The hydraulic cement mix of claim 6 in which said set retarder comprises calcium lignosulfonate and said first additive is taken from the group consisting of monomethylolurea, dimethylolurea and mixtures thereof.
Claim 7
Dependent Claim
33 words
The hydraulic cement mix of claim 7 in which said first 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 8
Dependent Claim
37 words
The hydraulic cement mix of claim 1 and including 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 9
Dependent Claim
15 words
The hydraulic cement mix of claim 9 in which said second adDitive comprises water-soluble formates.
Claim 10
Dependent Claim
15 words
The hydraulic cement mix of claim 10 in which said water-soluble formates comprise sodium formate.
Claim 11
Dependent Claim
24 words
The hydraulic cement mix of claim 10 in which said first additive is taken from the group consisting of monomethylolurea, dimethylolurea, and mixtures thereof.
Claim 12
Dependent Claim
33 words
The hydraulic cement mix of claim 12 in which said first 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 13
Dependent Claim
103 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 monomeric, water-soluble hydroxylated adduct formed by the reaction of an aldehyde and a urea, said additive being incorporated in an amount within the range of from about 0.01 percent to about 0.8 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 14
Dependent Claim
18 words
The process of claim 14 in which said additive is incorporated in said mix as a dry powder.
Claim 15
Dependent Claim
18 words
The process of claim 4 in which said additive is incorporated in said mix as a water mixture.
Claim 16
Dependent Claim
31 words
The process of claim 16 in which said additive is incorporated as a concentrated water mixture having an adduct concentration of at least about 50 percent by weight of said mixture.
Claim 17
Dependent Claim
11 words
The process of claim 14 in which the additive comprises monomethylolurea.
Claim 18
Dependent Claim
30 words
The process of claim 18 in which said 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
11 words
The process of claim 14 in which the additive comprises dimethylolurea.
Claim 20
Dependent Claim
30 words
The process of claim 20 in which said 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 21
Dependent Claim
68 words
The process of claim 14 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 22
Dependent Claim
29 words
The process of claim 22 in which said set retarder comprises calcium lignosulfonate and said first additive is taken from the group consisting of monomethylolurea, dimethylolurea and mixtures thereof.
Claim 23
Dependent Claim
35 words
The process of claim 23 in which said first additive is incorporated into 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 24
Dependent Claim
45 words
The process of claim 14 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 25
Dependent Claim
13 words
The process of claim 25 in which said second additive comprises water-soluble formates.
Claim 26
Dependent Claim
13 words
The process of claim 26 in which said water-soluble formates comprise sodium formate.
Claim 27
Dependent Claim
22 words
The process of claim 26 in which said first additive is taken from the group consisting of monomethylolurea, dimethylolurea, and mixtures thereof.
Claim 28
Dependent Claim
31 words
The process of claim 28 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 29
Dependent Claim
12 words
The process of claim 29 in which said first additive comprises di-methylolurea.
Claim 30
Dependent Claim
19 words
The process of claim 22 in which said first additive is incorporated in said mix in dry powder form.
Claim 31
Dependent Claim
19 words
The process of claim 22 in which said first additive is incorporated in said mix as a water mixture.
Claim 32
Dependent Claim
32 words
The process of claim 32 in whIch said first additive is incorporated as a concentrated water mixture having an adduct concentration of at least about 50 percent by weight of said mixture.
Claim 33
Dependent Claim
19 words
The process of claim 25 in which said first additive is incorporated in said mix in dry powder form.
Claim 34
Dependent Claim
19 words
The process of claim 25 in which said first additive is incorporated in said mix as a water mixture.
Claim 35
Dependent Claim
32 words
The process of claim 35 in which said first additive is incorporated as a concentrated water mixture having an adduct concentration of at least about 50 percent by weight of said mixture.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-14 | 1977-07-16 | 1978-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-14 | 1981-07-16 | 1982-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-14 | 1985-07-16 | 1986-01-15 | $7700.00 | Window Closed / Lapsed |