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US 4,486,350 AGranted
Process for the preparation of sulphur dyestuffs of the phthalocyanine series
AssigneeCassella Aktiengesellschaft
InventorsWolfgang Bauer, Klaus Kuhlein, Gert Nagl
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Abstract
Preparation of phthalocyanine sulphur dyestuffs is improved by reducing phthalocyaninesulphochlorides in the presence of hydriodic acid and a non-free metal reducing agent which converts iodine into hydriodic acid.
Claims15
In the process for preparation of phthalocyanine sulphur dyestuffs by reducing phthalocyaninesulphochlorides of the formula
- Pc(SO.sub.2 Cl).sub.n
- wherein Pc is a metal-free or metal-containing phthalocyanine moiety and n is an integer from 1 to 4, the improvement comprises reducing said phthalocyaninesulphochlorides in the presence of hydriodic acid and a reducing agent which converts iodine into hydriodic acid with the proviso that said reducing agent is other than a free metal.
The process according to claim 2 wherein hydriodic acid is present in catalytic amounts.
Dependencies are inferred from the claim text.