Cement Additive For Stucco Applications
AssigneeW. R. Grace & Co.-Conn.
InventorsMichael B. MacKlin, Mark A. Franciosi, Leslie A. Jardine, Byong-wa Chun
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Abstract
An additive composition, a cement composition, and method for modifying rheology of an uncured masonry cement, comprising the use of at least one extra-cellular biopolymer, at least one anionic surfactant, and at least one cationic or amphoteric surfactant. Preferably, the biopolymer and surfactants are incorporated into the cement by incorporating the components into the grinding of clinker as part of the manufacture of the cement. Masonry cements produced by the invention have excellent workability, particularly when coarse sands are employed.
Claims20
An additive composition for modifying the rheology of a mortar cement, comprising:
- (a) at least one extra-cellular biopolymer in an amount no less than 0.01% and no greater than 2.0% based on said additive composition, said biopolymer being operative to increase the viscosity of an aqueous cementitous suspension having pH in the range of 11-13.5;
- (b) at least one anionic surfactant in an amount no less than 0.5% and no greater than 50.0%;
- and
- (c) at least one cationic or amphoteric surfactant in an amount no less than 0.5% and no greater than 50.0%;
- all percentages of components (a) through (c) expressed in terms of weight based on total weight of said additive composition.
The additive composition of claim 4 wherein said non-aqueous liquid is selected from the group consisting of an ethylene glycol or an alkanolamine.
A method for modifying a mortar cement, comprising:
- introducing to cement clinker before or during the intergrinding manufacture process of said cement clinker to produce cement,
- (a) at least one extra-cellular biopolymer in an amount no less than 1.0 ppm and no greater than 100.0 ppm;
- (b) at least one anionic surfactant in an amount no less than 2.8 ppm and no greater than 2800 ppm;
- and
- (c) at least one cationic or amphoteric surfactant in an amount no less than 1.5 ppm and no greater than 180 ppm;
- all ppm (parts-per-million) amounts herein being expressed in terms of dry weight actives based on dry weight of cement material including cement binder and any secondary cementitious materials.
Dependencies are inferred from the claim text.