초록 ▼

In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymer-containing plasticizer, or EO/PO comb polymer-containing plasticizer, and further containing clay, such as a smectite clay, which expands when in contact with water, the step of providing an agent op

In the preparation of aqueous cement compositions containing a plasticizer, such as an EO/PO polymer-containing plasticizer, or EO/PO comb polymer-containing plasticizer, and further containing clay, such as a smectite clay, which expands when in contact with water, the step of providing an agent operative to modify the clay whereby the plasticizer absorbing capability of the clay is reduced. In exemplary methods of the invention, the plasticizer is an EO/PO (e.g., oxyalkylene) plasticizer and preferably an EO/PO comb polymer, and the clay-activity-modifying agent may comprise an inorganic cation, an organic cation, a polar organic molecule capable of being absorbed by the clay, a clay dispersant (such as a polyphosphate), or a mixture thereof. For clay-activity-modifying agents which comprise a cation or a polar organic molecule, the agent is preferably added to the clay before water is introduced to the clay. For clay dispersant agents and some organic cations such as quaternary amines (which have a strong affinity for cationic exchange with the clay), the agent may be added before, during, or after water is introduced to the clay.

대표청구항 ▼

1. In the preparation of aqueous cement compositions containing a superplasticizer, said superplasticizer comprising a comb polymer having pendant groups comprising ethylene oxide and propylene oxide groups, and further containing a smectite clay which expands when in contact with water and which ha

1. In the preparation of aqueous cement compositions containing a superplasticizer, said superplasticizer comprising a comb polymer having pendant groups comprising ethylene oxide and propylene oxide groups, and further containing a smectite clay which expands when in contact with water and which has the ability to absorb said superplasticizer when it expands upon contact with water, the step of providing an agent operative to diminish the ability of said smectite clay to absorb said comb polymer superplasticizer when said smectite clay expands upon contact with water, said agent comprising an inorganic cation, an organic cation, a polar organic molecule, a clay dispersant operative to reduce absorptivity of said smectite clay, or mixture thereof.