| 摘要 |
<p>The dye consists in a mixture of powders, comprising a combination of pigments chosen from the group of natural colouring earths (ochres, umbers, reds), of the officinal dyeing alkaline-resistant and not photosensitive plants (indigo, madder, reseda, cartamo, guado), of vegetable charcoal, of some oxides with a low specific weight and of cobalt, mixed with mineral extenders (crystalline or amorphous calcium carbonates, talc, mica, kaolin, marble, lime, allum) and natural weak acids (ascorbic, tartaric, citric, boric). These natural weak acids together with carbonates create the important function of effervescence which helps disperse the dye quickly in little water before colouring white or neutral paint.</p> |
