| 摘要 |
A particulate hydrous mineral suitable for use as an opacifying pigment, filler or extender has a shape factor which is greater than S, where S is defined by Equation 1 as follows: S = (d 50 /0.036) + 20; where d 50 is the mean particle size of the particles of the mineral measured in microns. The particulate mineral is preferably a kaolin, which is particularly suitable for use in aqueous matt paint compositions. |
