| 摘要 |
Blue dyes are made by treating dianthrone ethylene of the formula <FORM:0978286/C4-C5/1> or a dichlorodianthrone ethylene derived from 1-chloroanthrone, with an alkali-metal hydroxide at an elevated temperature and in the presence of an organic sulphoxide having 2-4 carbon atoms, such as dimethyl sulphoxide or tetramethylene sulphoxide, until the reaction mixture is capable of forming a blue precipitate on oxidation, and subsequently oxidizing the leuco-compounds contained in the reaction mixture into blue dyes. Oxidizing agents mentioned are air, per-salts and hypochlorite. The dyes are pigment dyes but the dye obtained from the dichlorodianthrone ethylene can be condensed in an anthrimide melt to give vat dyestuffs. |
