Flexible non-chromate corrosion inhibitive primer

Patent metadata

Field	Value
Publication number	US-10072176-B2
Application number	US-201615186321-A
Country	US
Kind code	B2
Filing date	Jun 17, 2016
Priority date	Jun 19, 2015
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

Primer coating compositions include a thiol-terminated urethane-containing polyether prepolymer, a polyepoxide, calcium carbonate, and magnesium oxide. The coating compositions are useful as corrosion resistant primers in aerospace applications.

First claim

What is claimed is:

1. A primer composition comprising:
a thiol-terminated urethane-containing polyether prepolymer;
a polyepoxide;
from 5 wt % to 9 wt % calcium carbonate; and
from 3 wt % to 7 wt % magnesium oxide,
wherein wt % is based on the total weight of the primer composition.

2. The primer composition of claim 1 , wherein the ratio (wt %/wt %) of calcium carbonate to magnesium oxide is greater than 1.3.

3. The primer composition of claim 1 , wherein the primer composition comprises:
from 16 wt % to 26 wt % of the calcium carbonate; and
from 12 wt % to 20 wt % of the magnesium oxide,
wherein wt % is based on the total solids weight of the composition.

4. The primer composition of claim 1 , wherein the polyepoxide comprises a novolac epoxy resin.

5. The primer composition of claim 1 , wherein,
the calcium carbonate comprises nanoparticles characterized by a mean particle diameter from 20 nm to 200 nm; and
the magnesium oxide comprises nanoparticles characterized by a mean particle diameter from 10 nm to 100 nm.

6. The primer composition of claim 1 , wherein the primer composition comprises:
from 8 wt % to 12 wt % of the thiol-terminated urethane-containing polyether prepolymer; and
from 1 wt % to 5 wt % of the polyepoxide,
wherein wt % is based on the total weight of the primer composition.

7. The primer composition of claim 1 , wherein the primer composition comprises:
from 20 wt % to 40 wt % of the thiol-terminated urethane-containing polyether prepolymer; and
from 7 wt % to 13 wt % of the polyepoxide,
wherein wt % is based on the total solids weight of the primer composition.

8. The primer composition of claim 1 , wherein the primer composition comprises from 55 wt % to 65 wt % of a solvent or combination of solvents, wherein wt % is based on the total weight of the primer composition.

9. The primer composition of claim 1 , wherein the primer composition comprises from 28 wt % to 40 wt % solids, wherein wt % is based on the total weight of the primer composition.

10. A cured primer coating prepared from the primer composition of claim 1 .

11. A substrate comprising the cured primer coating of claim 10 .

12. The substrate of claim 11 , wherein the substrate comprises aluminum or an aluminum alloy.

13. A multilayer coating, comprising,
a cured primer coating prepared from the primer composition of claim 1 ; and
a cured polyurethane coating overlying the cured primer coating.

14. A method of coating a surface, comprising:
applying the primer composition of claim 1 to a surface;
curing the primer composition to provide a cured primer coating;
applying a polyurethane coating over at least a portion of the cured primer coating; and
curing the polyurethane coating to provide a coated surface.

15. The method of claim 14 , wherein the surface comprises a surface of an aerospace vehicle.

16. A primer system, comprising:
a first part comprising:
a thiol-terminated urethane-containing polyether prepolymer; and
calcium carbonate; and

a second part comprising:
a polyepoxide; and
magnesium oxide.

17. The primer system of claim 16 , wherein,
the first part comprises:
from 18 wt % to 30 wt % of the thiol-terminated urethane-containing polyether prepolymer; and
from 11 wt % to 23 wt % of the calcium carbonate;
wherein wt % is based on the total weight of the first part; and

the second part comprises:
from 9 wt % to 17 wt % of the polyepoxide; and
from 16 wt % to 28 wt % of the magnesium oxide,
wherein wt % is based on the total weight of the second part.

18. The primer system of claim 16 , wherein the primer system, further comprises a third part, wherein the third part comprises a solvent.

19. The primer system of claim 18 , wherein the primer system comprises:
from 30 wt % to 42 wt % of the first part;
from 24 wt % to 30 wt % of the second part; and
from 30 wt % to 42 wt % of the third part,
wherein wt % is based on the total weight of the primer system.

20. A composition comprising the primer system of claim 18 , wherein the first part, the second part, and the third part are combined.

21. A primer composition comprising:
from 20 wt % to 40 wt % of a thiol-terminated urethane-containing polyether prepolymer;
from 7 wt % to 13 wt % of a polyepoxide;
from 16 wt % to 26 wt % calcium carbonate;
from 12 wt % to 20 wt % magnesium oxide; and
a solvent or combination of solvents;
wherein wt % is based on the total solids weight of the primer composition.

22. An aerospace vehicle comprising the cured primer coating of claim 10 .

Assignees

• Prc Desoto Int Inc

Inventors

• Abrami Siamanto
• Paclibar Elizabeth J

Classifications

• C08K2201/003

  Additives being defined by their diameter · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• C09D175/08

  from polyethers · CPC title

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title

• C08L63/00 Primary

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title