| 摘要 |
1394910 Optical whitening of minerals PLUSS-STAUFER AG 4 July 1973 [23 Oct 1972] 31845/73 Heading C1A A mineral is mixed with 0À5-3 wt. per cent of an optical brightening agent to produce a pigment or filler. The mixing may be done by grinding, e.g. in a sand, bead or ball mill or by means of a high-speed dispersing apparatus. Minerals referred to are chalk, calcite, dolomite, tale, barium sulphate and kaolin. The product may be used in coated paper, wall-paper or aqueous emulsion paint manufacture. |
