ADDITION METHOD OF POLYMER FOR IMPROVING PARTICLE SHAPE AND DISPERSION STABILITY OF PRECIPITATED CALCIUM CARBONATE BY ADDING PMAA(POLYMETHACRYLIC ACID) OR POLYOXYETHYLENE

摘要

PURPOSE: A method for adding a polymer to a precipitated calcium carbonate suspension is provided, to improve the particle shape and dispersion stability of a precipitated calcium carbonate by adding a polymer surfactant during the electrical conductivity change period in the preparation process of precipitated calcium carbonate. CONSTITUTION: The method comprises the steps of adding a polymer surfactant to a calcium carbonate suspension when the calcium carbonate suspension is prepared by injecting a CO2 gas with stirring at a room temperature, to allow the polymer surfactant to be adsorbed to the surface of the precipitated carbon carbonate; and analyzing the dispersion stability of the precipitated calcium carbonate after filtering and drying. Preferably the CO2 gas is injected with a flow rate of 500 L/min and the suspension is stirred with a velocity of 300 rpm at 20 deg.C to prepare a 3.5 wt% precipitated calcium carbonate suspension. Preferably the polymer surfactant is polyoxyethylene nonylphenyl ether and is added before the carbonation of precipitated calcium carbonate or during the first increase period of electrical conductivity in carbonation, or the polymer surfactant is PMAA(polymethacrylic acid) and is added during the first increase period of electrical conductivity in carbonation.