Pigment dispersant

A process for a preparation of at least one polymeric pigment dispersant comprising at least the steps of:

• reacting a linear di-block polymer with a compound of a formula (IV):
• wherein
• R1 is selected from the group consisting of unsubstituted or substituted naphthyl, unsubstituted or substituted anthracenyl and unsubstituted or substituted phenanthrenyl;
• R2 is selected from the group consisting of a hydrogen;
• a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• R3 is selected from the group consisting of a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• or
• R2 and R3 together with the carbon atoms to which they are bonded form a substituted phenyl or a substituted C3-C10 cycloalkyl or a substituted C4-C10 cycloalkenyl, which are each substituted with one —C(═O)—OH group;
• at a temperature from ≥80° C. to ≤150° C.;
• and
• wherein the linear di-block polymer comprises a first and a second block and is obtained by a living free radical polymerization, optionally in the presence of a solvent.

A process for a preparation of at least one polymeric pigment dispersant comprising at least the steps of:

• (a) reacting a random polymer with a compound of a formula (IV):
• wherein
• R1 is selected from the group consisting of unsubstituted or substituted naphthyl, unsubstituted or substituted anthracenyl and unsubstituted or substituted phenanthrenyl;
• R2 is selected from the group consisting of a hydrogen;
• a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• R3 is selected from the group consisting of a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• or
• R2 and R3 together with the carbon atoms to which they are bonded form a substituted phenyl or a substituted C3-C10 cycloalkyl or a substituted C4-C10 cycloalkenyl, which are each substituted with one —C(═O)—OH group;
• and
• (b) reacting the compound obtained in step (a) with at least one monomer of a lactone at a temperature from ≥30° C. to ≤190° C.

A process for a preparation of at least one polymeric pigment dispersant comprising at least the steps of:

• (a) reacting at least one polyalkylene glycol monoalkyl ether and at least one carboxylic acid anhydride at a temperature in a range from ≥70° C. to ≤140° C. to obtain a mixture;
• and
• (b) reacting the mixture obtained in step (a) with a random polymer and a compound of a formula (IV):
• wherein
• R1 is selected from the group consisting of unsubstituted or substituted naphthyl, unsubstituted or substituted anthracenyl and unsubstituted or substituted phenanthrenyl;
• R2 is selected from the group consisting of a hydrogen;
• a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• R3 is selected from the group consisting of a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• or
• R2 and R3 together with the carbon atoms to which they are bonded form a substituted phenyl or a substituted C3-C10 cycloalkyl or a substituted C4-C10 cycloalkenyl, which are each substituted with one —C(═O)—OH group;
• at a temperature in a range from ≥70° C. to ≤140° C.

A compound of formula (IV)

• wherein
• R1 is selected from the group consisting of unsubstituted or substituted naphthyl, unsubstituted or substituted anthracenyl and unsubstituted or substituted phenanthrenyl;
• R2 is selected from the group consisting of a hydrogen;
• a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• R3 is selected from the group consisting of a linear or a branched, substituted C1-C14 alkyl and a linear or branched, substituted C2-C14 alkenyl, which are each substituted with one —C(═O)—OH group;
• or
• R2 and R3 together with the carbon atoms to which they are bonded form a substituted phenyl or a substituted C3-C10 cycloalkyl or a substituted C4-C10 cycloalkenyl which are each substituted with one —C(═O)—OH group;
• whereby N-napthalenyl-4-carboxy-1,2-phthalimide is excluded.

A compound of formula (IV)

• wherein
• R1 is selected from the group consisting of unsubstituted naphthyl and naphthyl substituted with 1, 2 or 3 —OH;
• and
• R2 and R3 together with the carbon atoms to which they are bonded form a ring selected from the group consisting of phenyl and cyclohexyl which are each substituted with one —C(═O)—OH group.