| 摘要 |
<p>1,181,372. Titanium dioxide compositions. COSDEN OIL & CHEMICAL CO. 7 Feb., 1967 [8 Feb., 1966], No. 5727/67. Heading C3P. The greying of titanium dioxide pigmented compositions imparted during abrasive mixing, i.e. dry mixing in contact with metallic surfaces under conditions where the metal rubs off and discolours the pigment, is reduced by carrying out the mixing in the presence of up to 1% by wt. of a friable, dust-forming, colourless, alkaline inorganic solid containing or producing during the mixing particles having a size of less than 60 mesh U.S. Standard Sieve. The solid may be sodium hydroxide, calcium oxide, barium oxide, strontium oxide, magnesium oxide, calcium hydroxide, sodium bicarbonate, potassium carbonate, or sodium aluminate or borate and may contain an oxidizing agent, e.g. potassium persulphate or hydrogen peroxide. The composition may comprise particles, e.g. beads, of polystyrene.</p> |
