SODIUM POLYSILICATE CRYSTAL HYDRATES AND METHODS FOR THEIR PREPARATION Russian patent published in 1998 - IPC

FIELD: sealing materials. SUBSTANCE: sodium polysilicate crystal hydrates can be applied as gel-forming component, e.g. when manufacturing heat-insulation materials, when creating high-quality mineral sealing layers from bound grounds, and when providing waterproofing in oil-production industry. Invention aims at preparing water-soluble crystal hydrates with wide temperature range of using as gel-formation agent. Such requirements are met when using, as gel-forming component, new crystal hydrates having general formula N₂O(4-6)SiO₂•(8-10)H₂O. Preparation: 10-16% aqueous silicon dioxide hydrosol is added under stirring to 20-30% sodium silicate aqueous solution at 70-100 C in proportion 1:(1-1.5), respectively. Mixture is incubated at this temperature for at most 0.5 h and then dehydrated to water content 25.4-35.9 wt %. EFFECT: Improved physico-chemical characteristics of materials. 2 cl, 5 tbl