Pigment pastes comprising an aqueous dispersion of a copolymer

Patent metadata

Field	Value
Publication number	US-10040962-B2
Application number	US-201415104828-A
Country	US
Kind code	B2
Filing date	Nov 19, 2014
Priority date	Dec 18, 2013
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

The present invention relates to a pigment paste comprising at least one aqueous dispersion comprising at least one copolymer, said copolymer being preparable by (i) initially charging an aqueous dispersion of at least one polyurethane, and then (ii) polymerizing a mixture of olefinically unsaturated monomers in the presence of the polyurethane from (i), in which (a) a water-soluble initiator is used, (b) the olefinically unsaturated monomers are metered in such that a concentration of 6.0% by weight, based on the total amount of olefinically unsaturated monomers used for polymerization, in the reaction solution is not exceeded over the entire reaction time, and (c) the mixture of the olefinically unsaturated monomers comprises at least one polyolefinically unsaturated monomer, and further comprising a pigment, where the weight ratio of pigment to copolymer is at least 1.5. The invention further relates to the use of the copolymer for dispersion of pigments.

First claim

The invention claimed is:

1. A pigment paste, comprising:
at least one aqueous dispersion, comprising:
at least one pigment, and
at least one copolymer,
wherein said copolymer is obtained by
(i) initially charging an aqueous dispersion of at least one polyurethane, and then
(ii) polymerizing a mixture of olefinically unsaturated monomers in the presence of the polyurethane from (i), wherein
(a) at least one water-soluble initiator is present for said polymerizing,
(b) said polymerizing comprises metering the olefinically unsaturated monomers into a reaction solution so that a concentration of 6.0% by weight, based on the total amount of olefinically unsaturated monomers used for polymerization, in the reaction solution is not exceeded over the entire reaction time, and
(c) the mixture of the olefinically unsaturated monomers comprises at least one polyolefinically unsaturated monomer,

wherein the weight ratio of the at least one pigment to the at least one copolymer is greater than 1.5.

2. The pigment paste as claimed in claim 1 , wherein
said polymerizing comprises metering the olefinically unsaturated monomers into a reaction solution so that a concentration of 4.0% by weight, based on the total amount of olefinically unsaturated monomers used for polymerization, in the reaction solution is not exceeded over the entire reaction time.

3. The pigment paste as claimed in claim 1 , wherein the mixture of olefinically unsaturated monomers of said polymerizing comprises 0.1 to 6.0 mol % of polyolefinically unsaturated monomers, based on the total amount of olefinically unsaturated monomers used for polymerization.

4. The pigment paste as claimed in claim 1 , wherein the mixture of olefinically unsaturated monomers of said polymerizing comprises 0.1 to 2.0 mol % of polyolefinically unsaturated monomers, based on the total amount of olefinically unsaturated monomers used for polymerization.

5. The pigment paste as claimed in claim 1 , wherein the mixture of olefinically unsaturated monomers of said polymerizing comprises 0.1 to 6.0 mol % of allyl methacrylate and no further polyolefinically unsaturated monomers.

6. The pigment paste as claimed in claim 1 , wherein the mixture of olefinically unsaturated monomers of said polymerizing comprises less than 10.0% by weight of vinylaromatic monomers, based on the total amount of olefinically unsaturated monomers.

7. The pigment paste as claimed in claim 1 , wherein the mixture of olefinically unsaturated monomers of said polymerizing does not comprise any vinylaromatic monomers.

8. The pigment paste as claimed in claim 1 , wherein a weight ratio of the at least one pigment to the at least one copolymer is greater than 2.0.

9. The pigment paste as claimed in claim 1 , wherein a weight ratio of the at least one pigment to the at least one copolymer is greater than 2.5.

10. The pigment paste as claimed in claim 1 , wherein a weight ratio of the at least one pigment to the at least one copolymer is 3.0 to 5.0.

11. The pigment paste as claimed in claim 1 , wherein the pigment is an effect pigment.

12. The pigment paste as claimed in claim 11 , wherein the pigment is at least one pigment selected from the group consisting of a platelet-shaped, aluminum pigments and a metal oxide-mica pigment.

13. The pigment paste as claimed in claim 1 , wherein the paste comprises a platelet-shaped aluminum pigment and at least one organic solvent.

14. The pigment paste as claimed in claim 1 , wherein the paste comprises a metal oxide-mica pigment and less than 1000 by weight of organic solvents.

15. A method of dispersing an effect pigment, comprising:
dispersing an effect pigment in water to form an aqueous dispersion comprising said effect pigment,
wherein said dispersing is carried out in the presence of a copolymer, and
wherein said copolymer is obtained by:
(i) initially charging an aqueous dispersion of at least one polyurethane, and then
(ii) polymerizing a mixture of olefinically unsaturated monomers in the presence of the polyurethane from (i), wherein
(a) at least one water-soluble initiator is present for said polymerizing,
(b) said polymerizing comprises metering the olefinically unsaturated monomers into a reaction solution so that a concentration of 6.0% by weight, based on the total amount of olefinically unsaturated monomers used for polymerization, in the reaction solution is not exceeded over the entire reaction time, and
(c) the mixture of the olefinically unsaturated monomers comprises at least one polyolefinically unsaturated monomer.

16. The pigment paste as claimed in claim 1 , wherein the at least one copolymer has a core-shell structure, wherein the core comprises the at least one polyurethane, and the shell comprises at least one polymer obtained by polymerization of the olefinically unsaturated monomers.

Assignees

• Basf Coatings Gmbh

Inventors

• Steinmetz Bernhard
• Luhmann Nadia
• Jankowski Peggy
• Matura Michael
• Reuter Hardy
• Schwarte Stephan

Classifications

• C08L75/06

  from polyesters · CPC title

• C08G18/4288

  modified by higher fatty oils or their acids or by resin acids · CPC title

• C09D17/001 Primary

  in aqueous medium (C09D17/003, C09D17/004 take precedence) · CPC title

• C09D17/006

  Metal · CPC title

• C09D175/06

  from polyesters · CPC title