DISPERSION LIQUID STABILITY EVALUATION METHOD

PROBLEM TO BE SOLVED: To provide a dispersion liquid stability evaluation method capable of quantitatively evaluating the stability of a dispersion liquid.SOLUTION: A dispersion liquid stability evaluation method evaluates the stability of a dispersion liquid with use of a sample liquid which forms an aggregate of dispersoid in a dispersion medium after the dispersion liquid is prepared. The dispersion liquid is a liquid dispersion medium having liquid or solid dispersoid dispersed therein. The dispersion liquid stability evaluation method includes: a dispersion step for dispersing dispersoid forming an aggregate in the dispersion medium; and a measurement step for measuring the quantity of the dispersoid dispersed in the dispersion step. The measurement step calculates the quantity of the dispersoid dispersed in the dispersion step as a ratio of the dispersoid in the dispersion liquid to a whole quantity, and calculates the dispersion speed on the basis of the variation of measurement values of the ratio changed with the passage of time. The dispersion liquid stability evaluation method evaluates by quantitatively indicating with respect to plural kinds of liquid samples the degree of aggregation of the aggregate by the dispersion speed and thereby comparing the stability of the plural kinds of dispersion liquids.