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US 7,597,721 B2Granted
Concentrated aqueous compositions of dyestuffs
AssigneeClariant Finance (BVI) Limited
InventorFriedrich Lehr
Life of this patent
Estimating the term…
Abstract
The present invention relates to a process for producing storage-stable concentrated aqueous dye preparations of anionic dyes, to the dye preparations as such, blends/shadings with further anionic dyes and to their use, especially for printing and dyeing fiber materials.
Claims14
A process for producing a storage-stable concentrated aqueous preparation of an anionic dye comprising the steps of providing an aqueous solution or suspension of at least one anionic crude dye of the formula (I)
- subjecting the aqueous solution or suspension to ultrafiltration to form an ultrafiltrated dye solution,
- and concentrating the ultrafiltrated dye solution, with the proviso that no additional solubilizers, dispersants or tensides are added.
Dependencies are inferred from the claim text.