Ambient cured coating compositions for cables and cable accessories
Compositions including a filler, an emissivity agent, a crosslinking facilitator, and a metal silicate binder are disclosed. The compositions can be curable at ambient conditions. Methods of coating overhead conductor and power transmission line accessories with such coating compositions are also disclosed.
1. A method of coating an overhead conductor, comprising:
providing a coating composition formed from a first part and a second part, wherein the first part comprises a filler, an emissivity agent, and a crosslinking facilitator comprising a latent acid compound, wherein the latent acid compound comprises condensed aluminum phosphate; and wherein the second part comprises a metal silicate binder;
applying the coating composition onto an outer surface of the overhead conductor; and
curing the coating composition at a temperature of from about 15° C. to about 40° C. to form a coated overhead conductor having a cured coating on the outer surface thereof; and
wherein the composition comprises:
about 35% to about 45%, by dry weight, of the filler;
about 15% to about 22%, by dry weight, of the emissivity agent;
about 4% to about 10%, by dry weight, of the crosslinking facilitator; and
about 25% to about 40%, by dry weight, of the metal silicate binder.
2. The method of claim 1 , wherein the first part and the second part are mixed together to form the coating composition.
3. The method of claim 1 , wherein applying the coating composition onto an outer surface of the overhead conductor comprises passing the overhead conductor through a flooded die that deposits a liquid suspension of the composition onto the outer surface of the overhead conductor.
4. The method of claim 1 , wherein curing the coating composition comprises allowing the composition to cure and dry under ambient conditions.
5. The method of claim 1 , wherein the touch to dry time is about 2 hours or less after curing the coating composition is initiated.
6. The method of claim 1 , wherein curing the coating composition is complete after about 10 days.
7. The method of claim 1 , wherein the latent acid compound is configured to release an acid component when subject to an environment having a pH of about 9 or more.
8. The method of claim 1 , wherein crosslinking of the coating composition crosslinks occurs at a pH of about 11 or less.
9. The method of claim 1 , wherein the filler comprises one or more of talc, calcined kaolin, aluminum oxide, aluminosilicate, and quartz.
10. The method of claim 1 , wherein the emissivity agent comprises one or more of silicon carbide, boron carbide, and titanium dioxide.
11. The method of claim 1 , wherein the metal silicate binder comprises one or more of potassium silicate, sodium silicate, lithium silicate, and colloidal silica.
12. The method of claim 1 , wherein the composition comprises the crosslinking facilitator at about 10% to about 30% by weight of the metal silicate binder.
13. The method of claim 1 , wherein the composition further comprises a liquid carrier, and wherein the total solids content of the composition is about 35% to about 55%.
14. The method of claim 13 , wherein the liquid carrier comprises water.
15. The method of claim 1 , wherein the coated overhead conductor has an operating temperature that is about 10° C. lower than the operating temperature of an uncoated overhead conductor.
16. The method of claim 1 , wherein the coated overhead conductor passes a 0.5 inch mandrel bend test, such that the coating shows no visible cracks when bent on a mandrel having a diameter of 0.5 inches.
17. The method of claim 1 , wherein the coated overhead conductor passes a 1 inch mandrel bend test after immersion in water at 30° C. for 7 days, such that the coating shows no visible cracks when bent on a mandrel having a diameter of 1 inch.
18. A method of coating an overhead conductor, comprising:
providing a coating composition comprising:
about 35% to about 45%, by dry weight, of a filler;
about 15% to about 22%, by dry weight, of an emissivity agent;
about 4% to about 10%, by dry weight, of a crosslinking facilitator comprising a latent acid compound; wherein the latent acid compound comprises condensed aluminum phosphate and
about 25% to about 40%, by dry weight, of a metal silicate binder;
wherein the composition comprises the crosslinking facilitator at about 10% to about 30% by weight of the metal silicate binder;
applying the coating composition onto an outer surface of the overhead conductor; and
curing the coating composition at a temperature of from about 15° C. to about 40° C. to form a coated overhead conductor having a cured coating on the outer surface thereof, wherein curing the coating composition comprises allowing the composition to cure and dry under ambient conditions;
wherein the coated overhead conductor passes a 1 inch mandrel bend test after immersion in water at 30° C. for 7 days, such that the coating shows no visible cracks when bent on a mandrel having a diameter of 1 inch.