ADHESION-PROMOTING AGENT FOR PROTECTIVE COATINGS

• US 20100266855A1
• Filed: 12/22/2008
• Published: 10/21/2010
• Est. Priority Date: 12/27/2007
• Status: Abandoned Application

• Current Assignee: Axalta Coating Systems Ip Co Llc (Axalta Coating Systems Ltd.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Zukowski, David M.
• Application Number:
  US12/746,531
• Publication Number:
  US 20100266855A1
• Time in Patent Office: Days
• US Class Current: 428/425.800
• CPC Class Codes: C08G 18/10 Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
• CPC Class Codes: C08G 18/2865 Compounds having only one primary or secondary amino group; Ammonia
• CPC Class Codes: C08G 18/325 containing secondary or tertiary amino groups C08G18/3228, C08G18/3234, C08G18/3246 take precedence
• CPC Class Codes: C08G 18/5024 containing primary and/or secondary amino groups
• CPC Class Codes: C08G 18/6685 with compounds of group C08G18/3225 or polyamines of C08G18/38
• CPC Class Codes: C08G 18/722 Combination of two or more aliphatic and/or cycloaliphatic polyisocyanates
• CPC Class Codes: C08G 18/792 formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
• CPC Class Codes: C08G 18/798 containing urethdione groups
• CPC Class Codes: C08G 18/809 containing silicon
• CPC Class Codes: C09D 175/02 Polyureas
• CPC Class Codes: Y10T 428/31605 Next to free metal

Abstract

The present invention relates to an adhesion-promoting agent that contains at least 1.5 isocyanate groups per molecule and at least one urea linked silane group, coating compositions containing the adhesion promoting agent and methods for adhering protected coatings to a substrate. The adhesion-promoting agent is especially useful as an additive to the crosslinking component of a two component coating composition. The coating composition is especially useful for use as a protective coating on a previously coated or uncoated substrate such as an automobile.

Claims

1. A substrate coated by a dried and cured layer of a polyurea coating composition wherein the polyurea coating composition comprises an adhesion-promoting agent that is the reaction product of a polyisocyanate having, on average, at least 2.5 isocyanate groups per molecule and an isocyanate-reactive compound having at least 1 silicon-containing functional group.

2. The substrate of claim 1 wherein the isocyanate-reactive compound is an amine.

3. The substrate of claim 1 wherein the adhesion-promoting agent has, on average, at least 1.5 isocyanate groups per molecule and, on average, 2 or more silicon-containing functional groups per molecule.

4. The substrate of claim 1 wherein the adhesion-promoting agent is;

5. The substrate of claim 1 wherein the substrate is a metal substrate.

6. The substrate of claim 1 wherein the substrate is a component of a truck.

7. A polyurea coating composition comprising

A) a crosslinkable component consisting essentially of compounds, oligomers and/or polymers that have amine functional groups;

and

B) a crosslinking component comprising isocyanate functional compounds, oligomers and/or polymers;

wherein said crosslinking component includes an adhesion-promoting agent comprising the reaction product of a polyisocyanate and a isocyanate-reactive compound having at least 1 silicon-containing functional group.

9. The coating composition of claim 7 wherein said isocyanate-reactive compound is an amine.

10. The polyurea coating composition of claim 7 wherein the isocyanate-reactive compound is N,N-bis(3-trimethoxypropylsilyl)amine.

11. The polyurea coating composition of claim 7 wherein the adhesion-promoting agent is;

12. The polyurea coating composition of claim 7 wherein the adhesion-promoting agent comprises, on average, at least 1.5 unreacted isocyanate functional groups per molecule.

13. The polyurea coating composition of claim 7 wherein said adhesion-promoting agent is produced by the process of contacting a polyisocyanate compound with an isocyanate-reactive secondary amine compound having at least 1 silicon-containing functional group;

wherein the ratio of isocyanate functional groups to amine functional groups is in the range of from 2.5;

1 to 20;

1.

14. The polyurea coating composition of claim 7 wherein the isocyanate-reactive compound comprises an amine functional group and 2 or more silicon-containing functional groups.

16. The polyurea composition of claim 7 wherein said reaction product is:

a polyisocyanate functional allophanate;

a polyisocyanate functional isocyanurate;

or a polyisocyanate functional biuret.

15. The polyurea coating composition of claim 8 wherein the ratio of isocyanate groups in said crosslinking component to amine groups in said crosslinkable component is in the range of from 1:

0.5 up to 1;

2.

17. A method of adhering a protective coating to a coated substrate, wherein the coated substrate comprises a previously dried and cured coating layer, said method comprising the steps of:

a. applying a polyurea coating composition to the coated substrate, wherein the polyurea coating composition comprises an adhesion-promoting agent that is the reaction product of (1) a polyisocyanate having, on average, at least 2.5 isocyanate groups per molecule with (2) an isocyanate-reactive compound having at least 1 silicon-containing functional group;

b. curing the applied polyurea coating composition.

18. The method of claim 17 wherein the isocyanate-reactive compound is an amine.

19. The method of claim 17 wherein the previously dried and cured layer of coating composition comprises a resin having silane functional groups.

20. The method of claim 17 wherein the substrate is a motor vehicle.

21. The method of claim 17 wherein the substrate is a truck bed.