Clearcoat coating composition, method for production and use

Patent metadata

Field	Value
Publication number	US-9617448-B2
Application number	US-201314374389-A
Country	US
Kind code	B2
Filing date	Feb 1, 2013
Priority date	Feb 3, 2012
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Described is a clearcoat coating composition, its use, and a process for preparing the clearcoat coating composition. The clearcoat coating composition comprises (A) at least one polyester having an OH number of 80-250 mg KOH/g; (B) at least one butanol-etherified melamine-formaldehyde resin having a crosslinking onset temperature between 65° C.-100° C. lower than the crosslinking onset temperature of hexamethoxy-methylmelamine; (C) at least one butanol-etherified melamine-formaldehyde resin having a crosslinking onset temperature between 30° C.-60° C. lower than the crosslinking onset temperature of hexamethoxymethylmelamine; (D) at least one organic urea compound as rheological assistant; and (E) at least one acid catalyst.

First claim

What is claimed is:

1. A clearcoat coating composition comprising
(A) at least one polyester having an OH number of 100-220 mg KOH/g,
comprising
(A1) 10 to 20 mol % of at least one acyclic, aliphatic, branched polyol having two hydroxyl groups,
(A2) 5 to 15 mol % of at least one acyclic, aliphatic, branched polyol having three hydroxyl groups,
(A3) 10 to 20 mol % of at least one acyclic, aliphatic, branched polyol having four hydroxyl groups,
(A4) 25 to 40 mol % of at least one cycloaliphatic 1,2-dicarboxylic acid and/or the anhydride of this dicarboxylic acid, and
(A5) 20 to 35 mol % of isononanoic acid,

wherein the molar fractions are based in each case on the total molar fraction of the compounds (A1) to (A5) and wherein this total molar fraction accounts for at least 70 mol % of the compounds present in the polyester (A);
(B) at least one melamine-formaldehyde resin etherified with n-butanol or isobutanol having a crosslinking onset temperature between 65° C.-100° C. lower than the crosslinking onset temperature of hexamethoxymethylmelamine;
(C) at least one melamine-formaldehyde resin etherified with n-butanol or isobutanol having a crosslinking onset temperature between 30° C.-60° C. lower than the crosslinking onset temperature of hexamethoxymethylmelamine;
(D) at least one organic urea compound as rheological assistant; and
(E) at least one acid catalyst.

2. The clearcoat coating composition of claim 1 , comprising
the at least one polyester (A) in an amount of 12% to 45% by weight,
the at least one melamine-formaldehyde resin etherified with n-butanol or isobutanol (B) in an amount of 2% to 10% by weight,
the at least one melamine-formaldehyde resin etherified with n-butanol or isobutanol (C) in an amount of 5% to 20% by weight,
the at least one organic urea compound (D) as rheological assistant in an amount of 0.1% to 7% by weight, and
the at least one acid catalyst in an amount of 0.01 to 3% by weight,
based in each case on the total amount of the clearcoat coating composition.

3. The clearcoat coating composition of claim 1 , further comprising at least one (meth)acrylate (co)polymer (DD) having a glass transition temperature of −40° C. to 70° C. and an OH number of 60 to 200 mg KOH/g.

4. The clearcoat coating composition of claim 2 , further comprising at least one (meth)acrylate (co)polymer (DD) having a glass transition temperature of −40° C. to 70° C. and an OH number of 60 to 200 mg KOH/g in an amount of 5% to 20% by weight, based on the total amount of the clearcoat coating composition.

5. The clearcoat coating composition of claim 1 , further comprising at least one organic solvent.

6. The clearcoat coating composition of claim 2 , further comprising at least one organic solvent in an amount of 10% to 60% by weight, based on the total amount of the clearcoat coating composition.

7. The clearcoat coating composition of any of claim 1 , further comprising at least one tris(alkoxycarbonylamino)-1,3,5-triazine, in an amount of 0.5% to 10% by weight, based on the total amount of the clearcoat coating composition.

8. The clearcoat coating composition of claim 1 , wherein the at least one organic urea compound as rheological assistant is an adduct of a polyisocyanate and an araliphatic or aliphatic primary monoamine.

9. The clearcoat coating composition of claim 1 , wherein the acid catalyst is a sulfonic acid catalyst selected from the group consisting of free sulfonic acids and amine-blocked sulfonic acids.

10. A process for preparing the clearcoat coating composition of claim 1 , the process comprising mixing the components (A), (B), (C), (D), and (E).

11. The process of claim 10 , wherein the urea compound is added in the form of a paste which comprises a mixture of the urea compound with a polyester and/or with a (meth)acrylate (co)polymer and at least one organic solvent.

12. The process of claim 11 , wherein the paste comprises a (meth)acrylate (co)polymer (DD).

13. A method for producing a cured clearcoat on a substrate, the method comprising applying the clearcoat coating composition of claim 1 to a substrate and subsequently thermally curing at a temperature of 80 to 180° C.

14. The method of claim 13 , wherein the substrate comprises a precoated substrate having an existing paint coat, and the clearcoat coating composition is applied to the precoated substrate and optionally cured beforehand, to produce a multicoat paint system.

15. A multicoat coating produced according to the method of claim 14 .

Assignees

• Basf Coatings Gmbh

Inventors

• Weiher Christian
• Klein Günter
• Poppe Andreas
• Clausen-Meiring Ulrike
• Kleine Beckmann Helmut
• Auβmann Corinna
• Leitner Thomas

Classifications

• C09D167/00 Primary

  Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09D177/12; based on polyester-imides C09D179/08); Coating compositions based on derivatives of such polymers · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L2205/035

  containing four or more polymers in a blend · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• B05D3/02

  by baking {(B05D3/04 takes precedence)} · CPC title