Process for the production of a multi-layer coating

Patent metadata

Field	Value
Publication number	US-9573166-B2
Application number	US-201414503633-A
Country	US
Kind code	B2
Filing date	Oct 1, 2014
Priority date	Oct 2, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A process for the production of a multi-layer coating includes applying a coating layer from an aqueous pigmented coating composition A onto a substrate provided with an EDC primer and applying a base coat layer from an aqueous coating composition B overlying the coating layer. A clear coat layer is applied onto the base coat layer and the three coating layers are jointly bake-cured. The coating compositions A and B are different from each other and coating composition A comprises (i) binder solids, (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment, and (iv) talcum filler.

First claim

What is claimed is:

1. A process for the production of a multi-layer coating, the process comprising the steps of:
applying an about 10 to about 30 μm thick coating layer from an aqueous pigmented coating composition A onto a substrate provided with an EDC primer;
applying an about 10 to about 25 μm thick base coat layer from an aqueous coating composition B onto the coating layer;
applying an about 30 to about 50 μm thick clear coat layer onto the base coat layer; and
jointly bake-curing the three coating layers,
wherein aqueous pigmented coating composition A and aqueous coating composition B are different from each other,
wherein aqueous pigmented coating composition A comprises (i) binder solids (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment, and (iv) talcum filler,
wherein aqueous coating composition B consists essentially of a resin solids composition of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 5 to about 45 wt. % of aqueous polyurethane binder, about 15 to about 50 wt. % of melamine formaldehyde condensate resin and 0 to about 20 wt. % of one or more other binders, and
wherein the wt. % are calculated on a solids basis and total 100 wt. %.

2. The process of claim 1 , wherein aqueous pigmented coating composition A comprises (i) binder solids consisting of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 50 to about 90 wt. % of aqueous polyurethane binder and 0 to about 30 wt. % of one or more other binders, (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment, and (iv) talcum filler.

3. The process of claim 2 , wherein the coating layer applied from aqueous pigmented coating composition A is flashed off within about 30 seconds to about 5 minutes at an air temperature of about 20 to about 30° C.

4. The process of claim 2 , wherein the aqueous (meth)acryl copolymer latex binder is made by free-radical emulsion copolymerization of olefinically unsaturated free-radically copolymerizable comonomers.

5. The process of claim 1 , wherein aqueous pigmented coating composition A comprises aminoplast resins.

6. The process of claim 1 , wherein the free polyisocyanate is a mixture of one or more hydrophilic polyisocyanates and one or more conventional polyisocyanates and wherein aqueous pigmented coating composition A comprises an inert organic solvent.

7. The process of claim 6 , wherein the solids weight ratio between the one or more hydrophilic polyisocyanates and the one or more conventional polyisocyanates is about 80:20 to about 50:50.

8. The process of claim 1 , wherein the binder solids:free polyisocyanate solids weight ratio of aqueous pigmented coating composition A is about 2.5:1 to about 3.5:1.

9. The process of claim 1 , wherein the substrate is an automotive body or an automotive body part.

10. The process of claim 1 , wherein the sum of the coating thickness for the two-layer coating produced from the aqueous pigmented coating composition A and the aqueous coating composition B is about 20 to about 35 μm.

11. The process of claim 1 , wherein the coating layer applied from aqueous pigmented coating composition A is flashed off within about 30 seconds to about 5 minutes at an air temperature of about 20 to about 30° C.

12. A process for the production of a multi-layer coating, the process comprising the steps of:
applying an about 10 to about 30 μm thick coating layer from an aqueous pigmented coating composition A onto a substrate provided with an EDC primer,
applying an about 10 to about 25 μm thick base coat layer from an aqueous coating composition B onto the previously applied coating layer,
applying an about 30 to about 50 μm thick clear coat layer onto the base coat layer, and
jointly bake-curing the three coating layers,
wherein aqueous pigmented coating composition A and aqueous coating composition B are different from each other,
wherein coating composition A comprises (i) binder solids, (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment, and (iv) 2 to 3.5 wt. % of talcum filler based on total weight of the resin solids,
wherein the free polyisocyanate is a combination of one or more hydrophilic polyisocyanates and one or more conventional polyisocyanates,
wherein aqueous coating composition B consists essentially of a resin solids composition of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 5 to about 45 wt. % of aqueous polyurethane binder, about 15 to about 50 wt. % of melamine formaldehyde condensate resin and 0 to about 20 wt. % of one or more other binders, and
wherein the wt. % are calculated on a solids basis and total 100 wt. %.

13. The process of claim 12 , wherein aqueous pigmented coating composition A comprises (i) binder solids consisting of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 50 to about 90 wt. % of aqueous polyurethane binder and 0 to about 30 wt. % of one or more other binders, (ii) free polyisocyanate, and (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment.

14. The process of claim 12 , wherein aqueous pigmented coating composition A comprises an inert organic solvent.

15. The process of claim 12 , wherein the solids weight ratio between the one or more hydrophilic polyisocyanates and the one or more conventional polyisocyanates is about 80:20 to about 50:50.

16. A process for the production of a multi-layer coating, the process comprising the steps of:
applying an about 10 to about 30 μm thick coating layer from an aqueous pigmented coating composition A onto a substrate provided with an EDC primer,
applying an about 10 to about 25 μm thick base coat layer from an aqueous coating composition B onto the previously applied coating layer,
applying an about 30 to about 50 μm thick clear coat layer onto the base coat layer, and
jointly bake-curing the three coating layers,
wherein aqueous pigmented coating composition A is a two-component coating composition and aqueous coating composition B is a waterborne base coat composition, such that the aqueous pigmented coating composition A and the aqueous coating composition B are different from each other,
wherein aqueous pigmented coating composition A comprises (i) binder solids, (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon black pigment and/or titanium dioxide pigment, and (iv) talcum filler,
wherein aqueous coating composition B consists essentially of a resin solids composition of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 5 to about 45 wt. % of aqueous polyurethane binder, about 15 to about 50 wt. % of melamine formaldehyde condensate resin and 0 to about 20 wt. % of one or more other binders, and
wherein the wt. % are calculated on a solids basis and total 100 wt. %.

17. The process of claim 16 , wherein aqueous pigmented coating composition A comprises (i) binder solids consisting of about 10 to about 50 wt. % of aqueous (meth)acryl copolymer latex binder, about 50 to about 90 wt. % of aqueous polyurethane binder and 0 to about 30 wt. % of one or more other binders, (ii) free polyisocyanate, (iii) a pigment content free of special effect pigments and comprising carbon

Assignees

• Axalta Coating Systems Ip Co

Inventors

• Brunner Marcus
• Juengling Axel

Classifications

• C09D5/002

  Priming paints (C09D5/08 takes precedence) · CPC title

• C08G18/706

  the liquid medium being water · CPC title

• B05D2503/00

  Polyurethanes · CPC title

• B05D2401/20

  Aqueous dispersion or solution · CPC title

• B05D5/04

  to obtain a surface receptive to ink or other liquid (B05D5/02, {B41M5/52} take precedence) · CPC title