Process for producing homogeneous and storage-stable pastes, inks and paints using ionic liquids as dispersing additives

1. A process for coloring pastes, inks, paints, coverings, coatings or coating materials comprising:

providing an aqueous pigment paste including water, at least one pigment and a synergistic combination of dispersants including:

a). a primary dispersant; and

b). a secondary dispersant including at least one ionic liquid composed of at least one cation of the general formulae (1) to (4):

R 1 R 2 R 3 R 4 N ⊕   (1)

R 1 R 2 N ⊕ ═CR 3 R 4   (2)

R 1 R 2 R 3 R 4 P ⊕   (3)

R 1 R 2 P ⊕ ═CR 3 R 4   (4)

in which R 1 ,R 2 ,R 3 ,R 4 are identical or different and are hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more heteroatoms and having 2 to 30 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more functionalities selected from the group consisting of —O—C(O)—, —(O)C—O—, —NH—C(O)—, —(O)C—NH, —(CH 3 )N—C(O)—, —(O)C—N(CH 3 )—, —S(O 2 )—O—,—O—S(O 2 )—, —S(O 2 )—NH—, —NH—S(O 2 )—, —S(O 2 )—N(CH 3 )—, and —N(CH 3 )—S(O 2 )— and having 2 to 30 carbon atoms, a linear or branched, aliphatic or cycloaliphatic hydrocarbon radical with or without double bonds which is terminally functionalized by OH, OR′, NH 2 , N(H)R′, or N(R′) 2 , where R′ is a C 1 - to C 30 -alkyl radical with or without double bonds and has 1 to 30 carbon atoms, or a polyether —(R 5 —O) n —R 6 of blockwise or random construction,

where

R 5 is a linear or branched hydrocarbon radical containing 2 to 4 carbon atoms,

n is 1 to 100, and

R 6 hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, or a radical —C(O)—R 7 , where

R 7 is a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms or an alkylaryl radical having 7 to 40 carbon atoms.

2. The process as claimed in claim 1 wherein said at least one cation is derived from saturated or unsaturated cyclic compounds and also from aromatic compounds having at least one trivalent nitrogen atom in a 4- to 10-membered heterocyclic ring of the general formulae (5), (6) and (7)

and where

R 1 and R 2 are as defined above,

R can be a hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms or an alkylaryl radical having 7 to 40 carbon atoms, and

X can be an oxygen atom, a sulfur atom or a substituted nitrogen atom.

3. The process as claimed in claim 2 , wherein said at least one cation is a structure of general formula (8)

in which

R 8 ,R 9 ,R 10 ,R 11 ,R 12 are identical or different and are hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more heteroatoms and having 1 to 30 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more functionalities selected from the group consisting of —O—C(O)—, —(O)C—O—, —NH—C(O)—, —(O)C—NH, —(CH 3 )N—C(O)—, —(O)C—N(CH 3 )—, —S(O 2 )—O—, —O—S(O 2 )—, —S(O 2 )—NH—, —NH—S(O 2 )—, —S(O 2 )—N(CH 3 )—, and —N(CH 3 )—S(O 2 )— and having 1 to 30 carbon atoms, a linear or branched, aliphatic or cycloaliphatic hydrocarbon radical with or without double bonds which is terminally functionalized by OH, OR′, NH 2 , N(H)R′, or N(R′) 2 where R′ is a C 1 - to C 30 -alkyl radical with or without double bonds and has 1 to 30 carbon atoms, or a polyether —(R 5 —O) n —R 6 of blockwise or random construction,

where

R 5 is a hydrocarbon radical containing 2 to 4 carbon atoms,

n is 1 to 100 and

R 6 is hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, or a radical —C(O)—R 7 , where R 7 is a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms or an alkylaryl radical having 7 to 40 carbon atoms.

4. The process as claimed in claim 1 , wherein the at least one ionic liquid includes an anion selected from the group consisting of halides, bis(perfluoroalkylsulfonyl)amides, alkyl and aryl tosylates, perfluoroalkyl tosylates, nitrates, sulfates, hydrogensulfates, alkyl and aryl sulfates, polyether sulfates and polyethersulfonates, perfluoroalkyl sulfates, sulfonates, alkyl and arylsulfonates, perfluorinated alkyl- and arylsulfonates, alkyl- and arylcarboxylates, perfluoroaikylcarboxylates, perchlorates, tetrachloro-aluminates and saccharinates.

5. The process as claimed in claim 4 , wherein said anion is an anion of dicyanamide, tetrafluoroborate, hexafluorophosphate, phosphate or polyether phosphates.

6. The process as claimed in claim 4 , wherein said anion is an alkyl sulfate.

7. The process as claimed in claim 1 , wherein said secondary dispersant includes mixtures of two or more of said ionic liquids each in combination with at least one anion.

8. The process as claimed in claim 1 , wherein the at least one ionic liquid is present in an amount within the range from 0.1% to 98%, by weight, based on the total formulation.

9. The process as claimed in claim 8 , wherein said at least one ionic liquid is present in an amount from 0.1% to 20%.

10. The process as claimed in claim 8 , wherein said at least one ionic liquid is present in an amount 0.3% to 5%.

11. An aqueous or solvent-home paste, ink, paint, covering, coating or coating material comprising an aqueous pigment paste including water, at least one pigment and a synergistic combination of dispersants including:

a). a primary dispersant; and

b). a secondary dispersant including at least one ionic liquid composed of at least one cation of the general formulae (1) to (4):

R 1 R 2 R 3 R 4 N ⊕   (1)

R 1 R 2 N ⊕ ═CR 3 R 4   (2)

R 1 R 2 R 3 R 4 P ⊕   (3)

R 1 R 2 P ⊕ ═CR 3 R 4   (4)

in which R 1 ,R 2 ,R 3 ,R 4 are identical or different and are hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more heteroatoms and having 2 to 30 carbon atoms, a linear or branched aliphatic hydrocarbon radical with or without double bonds interrupted by one or more functionalities selected from the group consisting of —O—C(O)—, —(O)C—O—, —NH—C(O)—, —(O)C—NH, —(CH 3 )N—C(O)—, —(O)C—N(CH 3 )—, —S(O 2 )—O—, —O—S(O 2 )—, —S(O 2 )—NH—, —NH—S(O 2 )—, —S(O 2 )—N(CH 3 )—, and —N(CH 3 )—S(O 2 )— and having 2 to 30 carbon atoms, a linear or branched, aliphatic or cycloaliphatic hydrocarbon radical with or without double bonds which is terminally functionalized by OH, OR′, NH 2 , N(H)R′, or N(R′) 2 , where R′ is a C 1 - to C 30 -alkyl radical with or without double bonds and has 1 to 30 carbon atoms, or a polyether —(R 5 —O) n —R 6 of blockwise or random construction,

where

R 5 is a linear or branched hydrocarbon radical containing 2 to 4 carbon atoms,

n is 1 to 100, and

R 6 is hydrogen, a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms, an alkylaryl radical having 7 to 40 carbon atoms, or a radical —C(O)—R 7 , where R 7 is a linear or branched aliphatic hydrocarbon radical with or without double bonds and having 1 to 30 carbon atoms, a cycloaliphatic hydrocarbon radical with or without double bonds and having 5 to 40 carbon atoms, an aromatic hydrocarbon radical having 6 to 40 carbon atoms or an alkylaryl radical having 7 to 40 carbon atoms.

12. The method as claimed in claim 1 , wherein said providing includes adding said at least one ionic liquid to a mixture of said aqueous pigment paste and said primary dispersant.

13. The method as claimed in claim 1 , wherein said providing includes adding said combination of dispersants including said primary dispersant and said at least one ionic liquid to said aqueous pigment paste.