Aqueous coating composition comprising a thickener preparable from at least one polyamide and at least one further polymer

Patent metadata

Field	Value
Publication number	US-10233340-B2
Application number	US-201515505487-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Aug 22, 2014
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

The present invention relates to an aqueous coating composition comprising at least one binder (A) comprising at least one polymeric resin (A1), at least one pigment (B), and an aqueous dispersion of at least one thickener (C), where (C) is obtainable by a method comprising at least the steps (1), (2), (3), and (4), namely preparing a dispersion or solution of at least one polyurethane as a polymeric resin (C2) in at least one organic solvent (step (1)), preparing a mixture of the dispersion or solution obtained by step (1) and of a melt or solution of at least one polyamide as at least one polymeric resin (C1) having an acid number in a range from 1 to 200 mg of KOH per g of (C1) (step (2)), adding water to the mixture obtained by step (2) (step (3)), and removing the organic solvent from the mixture obtained by step (3), to give the aqueous dispersion of (C) (step (4)), to the use thereof for at least partly coating an optionally coated substrate with a basecoat film, to a coating method of this kind, and to a substrate coated accordingly.

First claim

The invention claimed is:

1. An aqueous coating composition comprising
at least one binder (A) comprising at least one polymeric resin (A1) and optionally at least one crosslinking agent (A2),
at least one pigment (B), and
an aqueous dispersion of at least one thickener (C),
wherein the at least one thickener (C) is obtainable by a method comprising at least (1), (2), (3), and (4):
(1) preparing a dispersion or solution of at least one polymeric resin (C2) in at least one organic solvent, the at least one polymeric resin (C2) being a polyurethane,
(2) preparing a mixture of the dispersion or solution obtained in (1) and of a melt or solution of at least one polyamide as at least one polymeric resin (C1), which has an acid number in a range from 1 to 200 mg of KOH per g of (C1),
(3) adding water to the mixture obtained in (2), and
(4) removing the at least one organic solvent from the mixture obtained in (3), to give the aqueous dispersion of the at least one thickener (C).

2. The coating composition as claimed in claim 1 , wherein the relative weight ratio of (C1) to (C2), based in each case on their solids content, is in the range from 1:10 to 1:1.5.

3. The coating composition as claimed in claim 1 , which has a solids content, in terms of the at least one thickener (C), in a range from 0.5 to 15 wt %, based on the total weight of the coating composition.

4. The coating composition as claimed in claim 1 , wherein the at least one polyamide used as the at least one polymeric resin (C1) has an acid number in a range from 30 to 120 mg of KOH per g of (C1).

5. The coating composition as claimed in claim 1 , wherein the at least one polyamide used as the at least one polymeric resin (C1) is at least obtainable by a reaction of at least one polycarboxylic acid selected from the group consisting of aliphatic C 3 -C 22 dicarboxylic acids, polymers of aliphatic C 14 -C 22 monocarboxylic acids, and mixtures thereof, with at least one aliphatic C 2 -C 12 diamine.

6. The coating composition as claimed in claim 1 , wherein the at least one thickener (C) has a melting point in the range from 20° C. to 100° C.

7. The coating composition as claimed in claim 1 , wherein the at least one pigment (B) comprises at least one effect pigment.

8. The coating composition as claimed in claim 1 , wherein the at least one binder (A) comprises at least one polyurethane and/or at least one poly(meth)acrylate and/or at least one polyester as the at least one polymeric resin (A1).

9. The coating composition as claimed in claim 1 , which comprises at least one further thickener (D) selected from the group consisting of metal silicates, thickeners based on poly(meth)acrylic acid, thickeners based on polyurethanes, polymeric waxes, and mixtures thereof.

10. The coating composition as claimed in claim 9 , wherein the relative weight ratio of the at least one thickener (C) to the at least one further thickener (D) is in the range from 80:1 to 1:1, based on their respective solids content.

11. A method for at least partly coating an optionally coated substrate with a basecoat film, comprising at least (a)
(a) at least partly coating at least one optionally coated substrate with a basecoat film, with the aqueous coating composition as claimed in claim 1 .

12. A basecoat film which is obtainable by at least partly coating at least one optionally coated substrate with the aqueous coating composition as claimed in claim 1 .

13. A substrate coated at least partly with the aqueous coating composition as claimed in claim 1 .

Assignees

• Basf Coatings Gmbh

Inventors

• Corten Cathrin
• Eierhoff Dirk
• Heimeier Ursula
• Kanngiesser Klaus-Juergen

Classifications

• B05D1/007

  using an electrostatic field (B05D1/02 - B05D1/16 take precedence) · CPC title

• C09D7/43 Primary

  Thickening agents · CPC title

• C08L77/08

  from polyamines and polymerised unsaturated fatty acids · CPC title

• C09D175/04

  Polyurethanes · CPC title

• B05D1/02

  performed by spraying · CPC title