SELF-STRATIFYING COATING

• US 20110028612A1
• Filed: 10/06/2010
• Published: 02/03/2011
• Est. Priority Date: 10/08/2008
• Status: Active Grant

• Current Assignee: Eastern Michigan University, Toyota Motor Corporation
• Original Assignee: Eastern Michigan University, Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Talapatcharoenkit, Punthip, Templeman, Cynthia G., Baghdachi, Jamil
• Granted Patent: US 8,299,170 B2
• Time in Patent Office: Days
• US Class Current: 524/114
• CPC Class Codes: C08G 77/045 containing less than 25 silicon atoms
• CPC Class Codes: C08G 77/14 containing silicon bound to oxygen-containing groups C08G77/045 takes precedence
• CPC Class Codes: C08K 5/29 Compounds containing one or more carbon-to-nitrogen double bonds
• CPC Class Codes: C08K 5/5435 containing oxygen in a ring
• CPC Class Codes: C08K 5/549 containing silicon in a ring
• CPC Class Codes: C08L 67/025 containing polyether sequences
• CPC Class Codes: C09D 183/04 Polysiloxanes

Abstract

The present invention discloses a reactivity-based self-stratifying coating composition. The coating composition can include a polyol, silsesquioxane, a polyester polyol, and a crosslinker that form a mixture within a solvent. The polyol can be selected from a fluorinated polyether, a fluoroethylene-alkyl vinyl ether and/or a combination thereof. The silsesquioxane can be an epoxy functional silsesquioxane having a formula of (R)₆(C₆H₁₁O₂)₂(SiO_1.5)₈ where R can be selected from hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl, phenyl, and isomers thereof. In some instances, the epoxy functional silsesquioxane can be a di-epoxy silsesquioxane.

Claims

1. A reactivity-based self-stratifying coating composition comprising:

a polyol, a silsesquioxane, a polyester polyol and a crosslinker forming a mixture dispersed within a solvent.

2. The coating composition of claim 1, wherein the polyol is selected from the group consisting of a fluorinated polyether, a fluoroethylene-alkyl vinyl ether and a combination thereof.

3. The coating composition of claim 1, wherein the silsesquioxane is an epoxy functional silsesquioxane having a formula (R)₆(C₆H₁₁O₂)₂(SiO_1.5)₈ and R is selected from the group consisting of hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl, phenyl and isomers thereof.

4. The coating composition of claim 3, wherein the epoxy functional silsesquioxane is a di-epoxy silsesquioxane.

5. The coating composition of claim 1, wherein the polyester polyol has an aliphatic structure with pendant hydroxyl groups.

6. The coating composition of claim 5, wherein the polyester polyol is a linear hydroxyl with terminal ends.

7. The coating composition of claim 5, wherein the polyester polyol has a hydroxyl value of between 100 and 500.

8. The coating composition of claim 7, wherein the hydroxyl value is between 150 and 400.

9. The coating composition of claim 8, wherein the hydroxyl value is between 200 and 300.

10. The coating composition of claim 1, wherein the polyester polyol has a viscosity between 1,000 and 50,000 cPs.

11. The coating composition of claim 10, wherein the viscosity is between 5,000 and 25,000 cPs.

12. The coating composition of claim 11, wherein the viscosity is between 7,500 and 15,000 cPs.

13. The coating composition of claim 1, wherein the polyester polyol has an average molecular weight of between 100 and 2,500.

14. The coating composition of claim 1, wherein the average molecular weight is between 200 and 1,000.

15. The coating composition of claim 1, wherein the average molecular weight is between 200 and 750.

16. The coating composition of claim 1, wherein the crosslinker is an isocyanate-functional compound selected from the group consisting of hexamethylene diisocyanate (HDI), hexamethylene triisocyanate (HTI), methylene bis-(4-cyclohexyl isocyanate) (HMDI) and a combination thereof.

17. The composition of claim 1, wherein the solvent is selected from the group consisting of tetrahydrofuran (THF), dimethylacetamide (DMA) and a combination thereof.

18. The composition of claim 1, wherein the solvent is removed to form a self-stratifying coating composition.