Patent ID: 8551237

Claim:
A process for preparing a colorant of formula (Ia), (Ib) or (Ic), the process comprising: reacting, in a mixing apparatus, a reaction mixture comprising (a) a tetracarboxylic acid or an anhydride, bisanhydride, an acid chloride, or a salt of the tetracarboxylic acid, with a base comprising (b) at least one selected from the group consisting of (b1) an aliphatic amine, (b2) an aromatic amine, (b3) an aliphatic diamine, and (b4) an aromatic diamine, to obtain a product compound of formula (Ia), (Ib), or (Ic), or a mixture thereof wherein R 1 and R 2 are the same or different and independently represent phenylene, naphthylene, pyridylene, and R 1 and R 2 each are optionally substituted one or more times by at least one substituent selected from the group consisting of C 1 -C 22 -alkyl, C 3 -C 22 -alkenyl, C 1 -C 22 -alkoxy, hydroxyl, nitro, and halogen, R 3 and R 4 are the same or different and independently represent hydrogen, C 1 -C 22 -alkyl, aryl, C 1 -C 22 -aralkyl, Q: C 1 -C 20 -alkyl, aryl and R 3 and R 4 each are optionally substituted one or more times by at least one substituent selected from the group consisting of C 1 -C 22 -alkyl, C 1 -C 22 -alkoxy, hydroxyl, nitro, and halogen, X in each occurrence is the same or different and independently represents halogen, n and p are independently 0, 1, 2, 3, or 4, and m is 0, 1, 2, 3, or 4 wherein the mixing apparatus is a kneader-like reactor, a single-shaft kneader, or a multi-part/shaft kneader, wherein the reacting is carried out in the presence of at most 100 wt. % of (d) a wetting agent, based on a total weight of all other components in the reaction mixture, and wherein the reacting is carried out in no solvent other than said wetting agent.