| 摘要 |
In the case of cardboard and paper coating compositions, calcium sulphate mixed with kaolin in a proportion of less than 40 per cent by weight of the quantity of pigment causes problems, with conventional dispersions, in terms of viscosity and stability. From about 0.05 to 2 per cent by weight of amino and/or potassium compounds, calculated as the sum of nitrogen + potassium and based on the quantity of calcium sulphate, used according to the invention as additional dispersant enable the preparation of pigment mixtures containing from 20 to 40 per cent by weight of gypsum, without the occurrence of the problems mentioned above. |
