Dispersants

1. A dispersant based on polyamines or polyimines each having primary amino groups, wherein the polyamines or polyimines contain a first side chain based on two or more poly(oxy-C 1-6 -alkylenecarbonyl) compounds (A) selected from the group consisting of glycolic acid, lactic acid, hydroxyvaleric acid, hydroxycaproic acid, β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone and a second side chain wherein the second side chain is the reaction product of a primary amino group on the polyamine or polyimine with an alkyl acid (B) selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid wherein the molar ratio of the sum total of the poly(oxy-C 1-6 -alkylenecarbonyl) compounds (A) and alkyl acids (B) to primary amino groups of the polyamines or polyimines is less than 1.

2. The dispersant according to claim 1 , wherein the at least two or more polymers based on poly(oxy-C 1-6 -alkylenecarbonyl) compounds are selected from the group consisting of δ-valerolactone and ε-caprolactone.

3. The dispersant according to claim 1 , wherein the dispersant has a ratio of amine number to acid number of >20.

4. The dispersants according to claim 3 , wherein the polyimine is a polyethyleneimine.

5. The dispersant according to claim 4 , wherein the mean molecular weight (Mw) of the polyethyleneimine is between 200 and 600 000 g/mol.

6. The dispersant according to claim 5 , wherein the dispersant has an acid number of <10 mg KOH/g.

7. The dispersant according to claim 1 , wherein the dispersant has a ratio of amine number to acid number of >10.

8. A method for preparing dispersants according to claim 1 , comprising the reaction of polyamines or polyimines each comprising primary amino groups, with at least two or more polymers based on poly(oxy-C 1-6 -alkylenecarbonyl) compounds (A) selected from the group consisting of glycolic acid, lactic acid, hydroxyvaleric acid, hydroxycaproic acid, β-propiolactone, γ-butyrolactone, δ-valerolactone, and ε-caprolactone and alkyl acids (B) selected from the group consisting of acetic, methoxyacetic, propionic, pentanoic, hexanoic, caprylic, capric, lauric, ricinoleic, stearic acid and hydroxystearic acid, wherein an amidation of alkyl acids (B) with the polyamines or polyimines takes place, wherein the molar ratio of the sum total of poly(oxy-C 1-6 -alkylenecarbonyl) compounds (A) and alkyl acids (B) to primary amino groups of the polyamines or polyimines is less than 1.

9. The method according to claim 8 , wherein the molar ratio between the two or more different poly(oxy-C 1-6 -alkylenecarbonyl) chains (A) and the alkyl acids (B) is between 90/10 and 10/90, and wherein the poly(oxy-C 1-6 -alkylenecarbonyl) compounds (A) are homopolymers and wherein the homopolymers have different chain lengths.

10. The method according to claim 9 , wherein the polymers are prepared separately or in situ by polymerization of the homopolymers and then used for the reaction with polyamines or polyimines and alkyl acids (B).

11. The method according to claim 8 , wherein the least two or more polymers based on poly(oxy-C 1-6 -alkylenecarbonyl) compounds are selected from the group consisting of δ-valerolactone and ε-caprolactone.

12. The method according to claim 8 , wherein the alkyl acids (B) correspond to the polymerization initiator for preparation of the at least two or more polymers based on poly(oxy-C 1-6 -alkylenecarbonyl) compounds and are selected from the group of acetic, methoxyacetic, propionic, pentanoic, hexanoic, lauric, ricinoleic and stearic acid.

13. The method according to claim 10 , wherein the polyimine is a polyethyleneimine.

14. The method according to claim 13 , wherein the mean molecular weight (Mw) of the polyethyleneimine is between 200 and 600 000 g/mol.

15. The composition comprising a particulate solid and a dispersant according to claim 1 .

16. A method of making an article selected from the group consisting of dispersions, millbases, inks or printing ink, the method comprising the step of making the article with the composition according to claim 15 .