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US 4,443,369 AGranted
Sulphur dyestuffs
AssigneeBayer Aktiengesellschaft
InventorsHelmut Seidler, Manfred Soll, Klaus Wunderlich
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Abstract
Sulphur dyestuffs which can be obtained by sulphurizing, in a manner which is in itself known, the residual mixtures obtained on dinitrating anthraquinone or on dinitrating by-products from the preparation of 1-nitroanthraquinone and partially isolating 1,5- and 1,8- and, if appropriate, 1,6- and 1,7-dinitroanthraquinones, optionally after prior reduction and/or hydroxylation and/or introduction of nitro groups, and their use in dyeing cellulose or material containing cellulose.
Claims1
A sulphur dyestuff obtained by:
- a. dinitrating anthraquinone;
- b. partially removing 1,5- and 1,8- and 1,6- and 1,7-dinitroanthraquinones;
- and
- c. sulphurizing the residual mixture which contains 25 to 60% by weight of 1,6-/1,7-dinitroanthraquinones, 60 to 25% by weight of 1,5-/1,8-dinitroanthraquinones, the total content of 1,X-(X=5,6,7,8) dinitroanthraquinones being 50 to 85% by weight, and 2 to 6% by weight of 2,6-/2,7-dinitroanthraquinones.
1 more element
Dependencies are inferred from the claim text.