Coating compositions and methods including carbodiimides

Patent metadata

Field	Value
Publication number	US-12435239-B2
Application number	US-202218546451-A
Country	US
Kind code	B2
Filing date	Feb 17, 2022
Priority date	Feb 18, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Coated substrates and methods may comprise a multi-unit carbodiimide. The multi-unit carbodiimide may also be combined with a siloxane. The multi-unit carbodiimide and/or the siloxane may be used in a surface coating applied to a substrate, and an overcoat may be applied to the surface coating. The surface coating may chemically interact with the overcoat and/or the substrate to improve corrosion resistance and other properties of the coated substrate.

First claim

What is claimed is:

1. A method for improving adhesion of a coating to a substrate and/or for improving edge coverage and corrosion resistance of a coating on a substrate, comprising:
contacting at least a portion of the substrate with a surface coating comprising:
(i) a multi-unit carbodiimide of the formula (I):

wherein
n is at least 2; and

(ii) a siloxane of the formula (II):

 or
(iii) a compound formed from the reaction of the compound of formula (I) with the compound of formula (II) having the formula (III):

wherein:
R 1 and R 3 each independently comprise a group selected from alkyl, arylalkyl, cycloalkyl, ether, polyether, siloxane, urethane, urea, imine, amide, carbodiimide, isocyanate, carbonyl, and carbamate;
R 2 comprises a group selected from alkyl, arylalkyl, and cycloalkyl;
R 4 comprises a group selected from hydrogen, alkyl, arylalkyl, cycloalkyl, amine, and siloxane, wherein R 4 comprises at least one amine group;
R 5 comprises a comprises a group selected from alkyl, arylalkyl, cycloalkyl, amine, and amide;
m+p is at least 2; and
the dashed lines represent tautomerization wherein any one of the carbon-nitrogen bonds is a double bond;

applying, to the surface coating, an overcoat comprising a group reactive with the surface coating; and
curing overcoat to form a coating layer.

2. The method of claim 1 , wherein R 2 comprises a dicyclohexylmethane group of the following formula:

3. The method of claim 1 , wherein at least one of R 1 and R 3 comprises a siloxane group of the following formula:

wherein R 6 comprises a group selected from hydrogen, methyl, ethyl, and isopropyl.

4. The method of claim 1 , wherein the surface coating is formulated in an aqueous solution.

5. The method of claim 1 , wherein the contacting step further comprises binding the surface coating to at least a portion of the substrate by reacting the surface coating with at least one hydroxyl group on the substrate.

6. The method of claim 1 , wherein at least one of R 1 and R 3 comprise a group selected from a polyether, a methylstyrene, and a siloxane, and R 2 comprises a dicyclohexylmethane group.

7. The method of claim 1 , wherein at least one of R 1 and R 3 comprise a group selected from:
a polyether group of the formula:

wherein p is at least 6;

a methylstyrene group of the formula:

 and
a siloxane group of the formula:

wherein R 6 comprises a group selected from hydrogen, methyl, ethyl, and isopropyl.

8. The method of claim 1 , wherein the siloxane of formula (II) is part of a polysiloxane structure comprising at least two silicon atoms covalently bonded through an oxygen atom.

9. A coated substrate comprising:
a substrate; and
a coating applied to the substrate, the coating comprising:
a surface coating applied to at least a portion of the substrate, the surface coating comprising a multi-unit carbodiimide bonded to a siloxane and having the formula:

wherein:
R 1 and R 3 independently comprise a group selected from alkyl, arylalkyl, cycloalkyl, ether, polyether, siloxane, urethane, urea, imine, amide, carbodiimide, isocyanate, carbonyl, and carbamate;
R 2 comprises a group selected from alkyl, arylalkyl, and cycloalkyl;
R 4 comprises a group selected from alkyl, arylalkyl, cycloalkyl, amine, and siloxane, wherein R 4 comprises at least one amine group;
R 5 comprises a comprises a group selected from alkyl, arylalkyl, cycloalkyl, amine, and amide;
m+p is at least 2; and
the dashed lines represent tautomerization wherein any one of the carbon-nitrogen bonds is a double bond; and

an overcoat layer disposed on the surface coating and chemically bonded to the surface coating through an acid functionalized or hydroxyl group of the overcoat layer.

10. The coated substrate of claim 9 , wherein the coating has a thickness from 20 μm to 250 μm.

11. The coated substrate of claim 9 , wherein the surface coating is chemically bonded to at least a portion of the substrate through at least one hydroxyl group on the substrate.

12. The substrate of claim 9 , wherein the acid functionalized or hydroxyl group reacts with the multi-unit carbodiimide to chemically bond the overcoat layer to the surface coating.

13. The substrate of claim 9 , wherein the coating exhibits a total scribe creep of less than 4 mm after corrosion testing for 750 hours in accordance with ATSM B117.

14. The substrate of claim 9 , wherein at least one of R 1 and R 3 comprise a group selected from a polyether, a methylstyrene, and a siloxane, and R 2 comprises a dicyclohexylmethane group.

15. The coated substrate of claim 9 , wherein the siloxane is part of a polysiloxane structure comprising at least two silicon atoms covalently bonded through an oxygen atom.

16. A compound comprising a multi-unit carbodiimide bonded to a siloxane of the following formula:

wherein:
R 1 and R 3 independently comprise a group selected from alkyl, arylalkyl, cycloalkyl, ether, polyether, siloxane, urethane, urea, imine, amide, carbodiimide, isocyanate, carbonyl, and carbamate;
R 2 comprises a group selected from alkyl, arylalkyl, and cycloalkyl;
R 4 comprises a group selected from alkyl, arylalkyl, cycloalkyl, amine, and siloxane, wherein R 4 comprises at least one amine group;
R 5 comprises a group selected from alkyl, arylalkyl, cycloalkyl, amine, and amide;
m+p is at least 2; and
the dashed lines represent tautomerization wherein any one of the carbon-nitrogen bonds is a double bond.

17. The compound of claim 16 , wherein at least one of R 1 and R 3 comprise a group selected from a polyether, a methylstyrene, and a siloxane, and R 2 comprises a dicyclohexylmethane group.

18. The compound of claim 17 , wherein at least one of R 1 and R 3 comprise a group selected from:
a polyether group of the formula:

wherein p is at least 6;

a methylstyrene group of the formula:

 and
a siloxane group of the formula:

wherein R 6 comprises a group selected from hydrogen, methyl, ethyl, and

Assignees

• Ppg Ind Ohio Inc

Inventors

• Schneider John
• Neal Martin
• Kerchner Hilary Ann
• Roppo Johnathan Michael
• Zhou Hongying

Classifications

• C09D5/08

  Anti-corrosive paints · CPC title

• C09D5/03

  Powdery paints · CPC title

• C09D5/002 Primary

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

• C08G18/8108

  having only one isocyanate or isothiocyanate group · CPC title

• C08G18/758

  containing two or more cycloaliphatic rings · CPC title