Thiazine indigo pigments, solid solutions thereof and their preparation

摘要

A compound according to the formula (I)wherein R1 and R2 are independently the atoms necessary to complete the formation of a substituted or unsubstituted aromatic or aliphatic carbocyclic or heterocyclic ring system and R3 and R4 have the meaning indicated in claim 1, a new process for the preparation of such a compound, solid solutions and mixtures comprising such a compound and the use of a compound of formula (I) as a pigment.