MULTI-PHASE CALCIUM SILICATE HYDRATES, METHODS FOR THEIR PREPARATION, AND IMPROVED PAPER AND PIGMENT PRODUCTS PRODUCED THEREWITH

摘要

A method for the hydrothermal preparation of calcium silicate hydrates. Multi-phase calcium silicate hydrates,having unique physical and chemical properties, are prepared by hydrothermalreaction of specified ratios of CaO and SiO2, normallystarting from slurries of slaked lime and from fluxed calcined diatomaceousearth, each of which is at about the atmospheric boilingpoint before being mixed and charged to a reactor, and pressurized. Thehydrothermal reaction is carried out while maintaining theinitial dilution for a preselected reaction time at a preselected reactiontemperature. The calcium silicate hydrates produced havehigh water absorption and light scattering power, and have optical andphysical properties making them highly desirable as a fillersubstitute in papermaking.