Carboxy-functional dimer fatty acid-based reaction products and aqueous basecoat materials comprising said products

Patent metadata

Field	Value
Publication number	US-10472540-B2
Application number	US-201515322637-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	Jul 1, 2014
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

The present invention relates to a pigmented aqueous basecoat material comprising a carboxy-functional dimer fatty acid-based reaction product which is preparable by reaction of
(a) dimer fatty acids with
(b) at least one compound of the general structural formula (I)

where R is a C 3 to C 6 alkylene radical and n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 120 to 6000 g/mol, components (a) and (b) are used in a molar ratio of at least 1/1 and the resulting reaction product possesses a number-average molecular weight of 1000 to 20 000 g/mol and an acid number of 10 to 120 mg KOH/g.

First claim

The invention claimed is:

1. A pigmented aqueous basecoat material, comprising:
a carboxy-functional dimer fatty acid-based reaction product which is produced by reaction of
(a) at least on dimer fatty acid with
(b) at least one compound of the general structural formula (I):

wherein:
R is a C 3 to C 6 alkylene radical;
n is selected such that the compound (b) possesses a number-average molecular weight of 120 to 6000 g/mol;
components (a) and (b) are used in a molar ratio of at least 1/1; and
the reaction product possesses a number-average molecular weight of 1000 to 20 000 g/mol and an acid number of 10 to 120 mg KOH/g.

2. The basecoat material as claimed in claim 1 , wherein the dimer fatty acid comprises at least 90 wt % of dimeric molecules, less than 5 wt % of trimeric molecules, and less than 5 wt % of monomeric molecules.

3. The basecoat material as claimed in claim 1 , wherein the compound (b) possesses a number-average molecular weight of 180 to 2500 g/mol.

4. The basecoat material as claimed in claim 1 , wherein the group R in the general structural formula (I) comprises tetramethylene radicals.

5. The basecoat material as claimed in claim 1 , wherein components (a) and (b) are used in a molar ratio of 1.1/1 to 3/1.

6. The basecoat material as claimed in claim 1 , wherein the reaction product possesses a number-average molecular weight of 2500 to 10 000 g/mol.

7. The basecoat material as claimed in claim 1 , wherein the reaction product possesses an acid number of 12 to 80 mg KOH/g.

8. The basecoat material as claimed in claim 1 , wherein the components (a) and (b) are used in a molar ratio of 1.2/1 to 2/1.

9. The pigmented aqueous basecoat material as claimed in claim 1 , wherein the sum total of the weight-percentage fractions, based on the total weight of the pigmented aqueous basecoat material, of all the dimer fatty acid-based reaction products is 0.1 to 30 wt %.

10. The pigmented aqueous basecoat material as claimed in claim 1 , further comprising a polyurethane resin that is grafted by olefinically unsaturated monomers and comprises hydroxyl groups, and a melamine resin.

11. A carboxy-functional dimer fatty acid-based reaction product which is produced by reaction of
(a) at least one dimer fatty acids with
(b) at least one compound of the general structural formula (I):

wherein:
R is a C 3 to C 6 alkylene radical;
n is selected accordingly such that the polyether (b) possesses a number-average molecular weight of 120 to 6000 g/mol;
components (a) and (b) are used in a molar ratio of at least 1/1; and
the resulting reaction product possesses a number-average molecular weight of 1000 to 20 000 g/mol and an acid number of 10 to 120 mg KOH/g.

12. A pigmented aqueous basecoat material, comprising:
the reaction product of claim 11 ,
wherein the pigmented aqueous basecoat material is adapted to function as a basecoat material for improving the stability with respect to optical defects in paint systems.

13. A method for producing a multicoat paint system, the method comprising:
(1) applying the pigmented aqueous basecoat material of claim 1 to a substrate,
(2) forming a polymer film from the basecoat material applied in stage (1),
(3) applying a clearcoat material to the polymer film, and then
(4) curing the polymer film together with the clearcoat film.

14. The method as claimed in claim 13 , wherein the substrate is a metallic substrate coated with a cured electrocoat film, and all of the films applied to the electrocoat film are cured jointly.

15. A multicoat paint system produced by the method of claim 13 .

16. A method for improving stability with respect to optical defects in a paint system, the method comprising:
applying a pigmented aqueous basecoat material comprising the reaction product of claim 11 to a surface to form a basecoat; and
painting a surface of the basecoat.

Assignees

• Basf Coatings Gmbh

Inventors

• Steinmetz Bernhard
• Hoffmann Peter
• Reuter Hardy

Classifications

• C09D5/44

  for electrophoretic applications (processes for coating by electrophoresis C25D13/00) · CPC title

• C08G63/676

  in which at least one of the two components contains aliphatic unsaturation · CPC title

• C09D167/025 Primary

  containing polyether sequences · CPC title

• C09D175/06

  from polyesters · CPC title

• C08G18/4252

  derived from polyols containing polyether groups and polycarboxylic acids · CPC title