| 摘要 |
<p>of the Disclosure Vat dyestuffs of the formula (1) wherein R represents alkyl with 1 to 4 carbon atoms, R1 and R2 represent hydrogen or alkyl with 1 to 4 carbon atoms and each of A1 and A2 represents a vattable radical with 3 to 7 condensed rings are characterised by improved resistance to alkali and are suitable for dyeing and printing the most diverse materials, in particular fibres made from natural or regenerated cellulose.</p> |
