Single step creosote/borate wood treatment
Disclosed herein are preservative compositions and methods of using the same for reducing insect and microbial decay in wood. Also disclosed are wooden articles that have been treated with the compositions described herein.
1. A method of treating wood, comprising the steps of:
a) immersing the wood in a treatment solution; and
b) exposing the immersed wood from step (a) to conditions which cause boron to migrate into the interior of the wood;
wherein the treatment solution comprises (1) at least about 3% w/w of a reaction product of alkanolamine and borate; wherein the reaction product comprises an alkanolamine ester of the borate; and (2) at least about 90% w/w creosote;
wherein the borate comprises disodium octaborate tetrahydrate (DOT); and the treatment solution is greater than 98% free of water and is a homogeneously mixed blend.
2. The method of claim 1 , wherein the alkanolamine comprises a C 2 -C 6 monoalkanolamine.
3. The method of claim 1 , wherein the alkanolamine comprises monoethanolamine.
4. The method of claim 1 , wherein the composition comprises at least about 95% w/w creosote.
5. The method of claim 1 , wherein the creosote comprises heavy bunker C fuel oil.
6. The method of claim 1 , wherein the creosote comprises about 40 to 60% w/w heavy bunker C fuel oil.
7. The method of claim 1 , wherein at least about 40% w/w of the borate is disodium octaborate tetrahydrate (DOT).
8. The method of claim 1 , wherein the borate comprises disodium octaborate tetrahydrate (DOT) and boric acid.
9. The method of claim 1 , wherein the reaction product comprises unreacted borate.
10. The method of claim 1 , wherein the treatment solution further comprises biodiesel.
11. The method of claim 1 , wherein exposing the immersed wood to conditions which cause boron to migrate into the interior of the wood comprises pressure impregnation of the wood with the treatment solution.
12. The method of claim 11 , wherein the pressure impregnation operation comprises exposing the immersed wood to a temperature of between 160-240° F. and a pressure of 100-160 pounds per square inch (psi).
13. The method of claim 11 , wherein the pressure impregnation results in the wood having of boron content of at least about 0.11 pounds per cubic foot (pcf) Boric Acid Equivalent (BAE).
14. The method of claim 11 , wherein the pressure impregnation comprises exposing the immersed wood to a temperature of 190-210° F. and a pressure of 130-160 psi for 20 minutes to 5 hours.
15. The method of claim 1 , further comprising c) separating the treated wood from the treatment solution after the pressure impregnation; d) exposing the treated wood to an expansion bath; e) exposing the treated wood to a vacuum treatment after completion of the expansion bath.
16. The method of claim 1 , wherein the conditions which cause boron to migrate into the interior of the wood result in the wood having of boron content of at least about 0.05 pcf BAE.
17. The method of claim 1 , wherein the creosote comprises heavy bunker C fuel oil; the alkanolamine comprises monoethanolamine; and the borate comprises disodium octaborate tetrahydrate.
18. The method of claim 17 , wherein the treatment solution further comprises biodiesel.
19. The method of claim 1 , wherein the treatment solution has a specific gravity @ 38° C. of at least 1.08 (compared to water @ 15.5° C.).
20. The method of claim 1 , wherein the treatment solution comprises least about 95% w/w creosote; the creosote comprises about 40 to 60% w/w heavy bunker C fuel oil; at least about 40% w/w of the borate is disodium octaborate tetrahydrate (DOT); and the treatment solution further comprises biodiesel.
21. A method of treating wood, comprising the steps of:
pressure impregnation of wood immersed in a preservative solution at 160-240° F. and a pressure of 100-160 pounds per square inch (psi);
wherein the preservative solution comprises (1) at least about 90% w/w creosote;
and (2) at least about 3% w/w of a reaction product of alkanolamine and borate, which comprises an alkanolamine ester of the borate;
the borate includes boric acid and at least about 40% w/w of the borate is disodium octaborate tetrahydrate (DOT);
wherein the preservative solution is greater than 98% free of water and is a homogeneously mixed blend.