Carboxy-functional polyether-based reaction products and aqueous base coats containing the reaction products

Patent metadata

Field	Value
Publication number	US-10793744-B2
Application number	US-201615781227-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Dec 9, 2015
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A pigmented aqueous basecoat material is disclosed. The pigmented aqueous basecoat material includes a polyether-based reaction product which is preparable by a reaction of trimesic acid with at least one polyether of the general structural formula (I)

R is a C 3 to C 6 alkylene radical and n is selected accordingly such that the at least one polyether possesses a number-average molecular weight of 500 to 5000 g/mol. The trimesic acid and the at least one polyether are used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possesses an acid number of 10 to 50 mg KOH/g.

First claim

What is claimed is:

1. A pigmented aqueous basecoat material comprising a polyether-based reaction product which is prepared by a reaction of
(a) trimesic acid
with
(b) at least one polyether of a general structural formula (I)

in which
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 750 to 5000 g/mol,
the components (a) and (b) being used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possessing an acid number of 5 to 50 mg KOH/g.

2. The pigmented aqueous basecoat material as claimed in claim 1 , wherein the polyether (b) possesses a number-average molecular weight of 1500 to 3200 g/mol.

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

4. The pigmented aqueous basecoat material as claimed in claim 1 , wherein the components (a) and (b) are used in a molar ratio of 0.45/1 to 0.55/1.

5. The pigmented aqueous basecoat material as claimed in claim 1 , wherein the polyether-based reaction product possesses a number-average molecular weight of 1500 to 15 000 g/mol.

6. The pigmented aqueous basecoat material as claimed in claim 1 , which has an acid number of 10 to 30 mg KOH/g.

7. The pigmented aqueous basecoat material as claimed in claim 1 , wherein a sum total of the weight-percentage fractions, based on a total weight of the pigmented aqueous basecoat material, of all polyether-based reaction products is 0.1 to 20 wt %.

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

9. A polyether-based reaction product which is prepared by a reaction of
(a) trimesic acid
with
(b) at least one polyether of a general structural formula (I)

in which
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 750 to 5000 g/mol,
the components (a) and (b) being used in the reaction in a molar ratio of 0.7/2.3 to 1.6/1.7 and the resulting reaction product possessing an acid number of 5 to 50 mg KOH/g.

10. A method for improving a stonechip resistance of paint systems produced using a pigmented aqueous basecoat material comprising utilizing a reaction product as claimed in claim 9 in the pigmented aqueous basecoat material.

11. A method for producing a multicoat paint system comprising the steps of
(1) applying a pigmented aqueous basecoat material to a substrate,
(2) forming a polymer basecoat film from the pigmented aqueous basecoat material applied in step (1),
(3) applying a clearcoat material to the resultant polymer basecoat film, and subsequently
(4) curing the polymer basecoat film together with the clearcoat,
wherein the pigmented aqueous basecoat material as claimed in claim 1 is used in step (1).

12. The method as claimed in claim 11 , wherein the substrate from step (1) is a metallic substrate coated with a cured electrocoat, and all coats applied to the electrocoat are cured jointly.

13. The method as claimed in claim 11 , wherein the substrate from step (1) is a metal or plastics substrate.

14. A multicoat paint system producible by the method as claimed in claim 11 .

Assignees

• Basf Coatings Gmbh

Inventors

• Steinmetz Bernhard
• Hoffmann Peter
• Reuter Hardy

Classifications

• C08G63/668 Primary

  derived from polycarboxylic acids and polyhydroxy compounds · CPC title

• C09D167/025 Primary

  containing polyether sequences · CPC title

• C08L61/28

  with melamine · CPC title

• C08G65/3326

  aromatic · CPC title

• B05D3/0272

  with ovens · CPC title