| 摘要 |
Particles for use as pigments or fillers for paints and plastics materials comprise fine particles of a mineral such as calcium carbonate, calcium sulphate, barium carbonate, barium sulphate, magnesium carbonate, dolomite, kaolin, silica, mica or talc, treated at the same time in the absence of water with extremely fine particles of a white pigment of high refractive index and with a carboxylic or sulphonic acid of the aliphatic or aromatic series. An example relates to treating calcium carbonate by grinding to a particle size of 5 to 7 microns in the presence of titanium dioxide having a particle size of 0.1 micron and stearic acid, at a temperature of 50 to 80 DEG C. Other acids which may be used include oleic, lauric, abietic, oxalic, maleic, lactic, ricinoleic, adipic, salicylic, benzoic and naphtholsulphonic acids. |
