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US 2019/0161617 A1Published application
Method for preparing phenylaminohydroxyanthraquinones
AssigneeLANXESS Deutschland GmbH
InventorsHans-Ulrich BORST, Alexa MASSONG, Sabine SCHMAUSER
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Abstract
A method for producing 1,4-diphenylamino-5,8-dihydroxyanthraquinone provides a dye with high colour strength and excellent brilliance for colouring plastics.
Claims18
A method for preparing compounds of formula (I)
- in which R1 and R2 are each independently C1-C6-alkyl, the method comprising contacting 1,4-dichloro-5,8-dihydroxyanthraquinone of formula (II)
- with:
- at least one of the compounds of formulae (IIIa) and (IIIb)
- in which R1 and R2 have the definition specified for formula (I), and at least one base,
- in the presence of at least one 5- or 6-membered cyclic urea derivative.
2 more elements
1,4-Bis(4-tert-butylphenylamino)-5,8-dihydroxyanthraquinone (Solvent Green 28) having a brilliance of 0.3 to 0.8 dC measured in accordance with DIN EN ISO 11664-4, and/or a colour strength of 100 to 110% measured in accordance with DIN 55986 and DIN EN ISO 11664-4.
Dependencies are inferred from the claim text.