Solar reflective coatings systems
Disclosed are infrared reflective coating systems. The coating compositions include an infrared transparent pigment and an infrared reflective pigment.
1. A coating system comprising:
(a) a first coating layer having a CIELAB L* value of no more than 40 and comprising:
(i) a film-forming resin; and
(ii) a visibly absorbing infrared transparent pigment; and
(b) a second coating layer deposited beneath at least a portion of the first coating layer and comprising:
(i) a film-forming resin;
(ii) a thin flake metal or metal alloy infrared reflective pigment; and
(iii) a visibly absorbing infrared transparent pigment,
wherein the first coating layer and the second coating layer have a contrast ratio (L* second /L* first ) of 0.8:1 to 1.6:1;
wherein the coating system has a % total solar reflectance of at least 25%; and
wherein the second coating layer has a % TSR of at least 25%.
2. The coating system of claim 1 , wherein the contrast ratio is 1.0 to 1.5:1.
3. The coating system of claim 1 , wherein the contrast ratio is 0.8 to less than 1:1.
4. The coating system of claim 1 , wherein the visibly absorbing infrared transparent pigment is present in an amount of at least 20% by weight, based on the total solids weight of the composition from which the second coating layer is deposited.
5. The coating system of claim 1 , wherein the dark IR transparent pigment in the first coating layer comprises a perylene system pigment.
6. The coating system of claim 1 , wherein the dark IR transparent pigment in the first coating layer comprises a perylene system pigment.
7. The coating system of claim 1 , wherein the second coating layer has an L *value of no more than 30.
8. The coating system of claim 7 , wherein the second coating layer has an L* value of 25 to less than 30.
9. The coating system of claim 1 , wherein the weight ratio of (b)(ii) to (b)(iii) in the composition from which the second coating layer is deposited is at least 1.5:1.
10. The coating system of claim 9 , wherein the weight ratio is at least 5:1.
11. The coating system of claim 10 , wherein the weight ratio is at least 10:1.
12. The coating system of claim 11 , wherein the weight ratio is at least 20:1.
13. The coating system of claim 1 , wherein the IR reflective pigment comprises a metal and/or metal alloy flake pigment.
14. The coating system of claim 13 , wherein the flake pigment comprises aluminum.
15. An article comprising the coating system of claim 1 positioned on a surface of the article.
16. The article of claim 15 , wherein the article is an aircraft component.