| abstract |
The invention relates to foams for insulating cavities and structures, such as spaces between walls in houses. The inventive foam compositions are prepared in separate portions, generally comprising (A) cement and (B) foam. Air is added initially to foam one of the components or a mixture of components. In a first embodiment, the first component comprises an aqueous solution of polyvinyl alcohol and a dispersant. This component is mechanically foamed by injection of air, for example. After the mechanical foaming a second, cement component is added to the first component. This second component comprises an aqueous solution, mixture or suspension of magnesium oxide and barium metaborate, and a dispersant. In a second, preferred embodiment, the first component comprises an aqueous solution of polyvinyl alcohol and calcium chloride, which component is mechanically foamed by injection of air. After the foaming a second component is added, comprising an aqueous solution of Portland Cement, a dispersant and sodium metaborate. |