Stable wood preservative formulations

1. A stable wood preservative formulation comprising:

a. an amine-copper complex;

b. at least one azole compound selected from the group consisting of tebuconazole and propiconazole;

c. a cationic surfactant having the following structure:

wherein the value of m is at least 1 and at most 20, the value of n is at least 1 and at most 20, the value of a is at least 1 and at most 5, the value of b is at least 1 and at most 5; and

an isothiazole-based mold inhibitor;

wherein the weight ratio of the cationic surfactant to the at least one azole compound is from about 1:1 to about 15:1; and

wherein said azole remains stable in solution and does not phase separate over the course of about 15 days to about 365 days while the formulation is stored at a temperature of about 0° C. to about 50° C.

2. The stable wood preservative formulation of claim 1 , wherein said amine-copper complex comprises an amine selected from the group consisting of an alkanolamine, monoethanolamine, ethanolamine, diethanolamine, triethanolamine and ammonia.

3. The stable wood preservative formulation of claim 1 , wherein said amine-copper complex is prepared from a copper compound selected from the group consisting of copper metal, cuprous oxide, cupric oxide, copper hydroxide, copper carbonate, basic copper carbonate, copper oxychloride, copper 8-hydroxyquinolate, copper dimethyldithiocarbamate, copper omadine, and copper borate.

4. The stable wood preservative formulation of claim 1 , wherein X − is an anion selected from the group consisting of borate, chloride, carbonate, bicarbonate, bromide, iodides, formate, acetate, propionate, and other alkyl carboxylates.

5. The stable wood preservative formulation of claim 4 , wherein X − is borate, chloride, propionate, carbonate, or bicarbonate.

6. The stable wood preservative formulation of claim 1 , wherein the value of m is 1 and n is 10 or 12, and the value of a is 1, and the value of b is 1.

7. The stable wood preservative formulation of claim 1 , wherein said azole remains stable in solution and does not phase separate over the course of about 15 to about 360 days.

8. The stable wood preservative formulation of claim 1 , wherein said azole remains stable in solution and does not phase separate over the course of about 30 to about 90 days.

9. The stable wood preservative formulation of claim 1 , wherein said azole remains stable in solution and does not phase separate over the course of about 30 to about 60 days.

10. The stable wood preservative formulation of claim 1 , wherein said azole remains stable in solution and does not phase separate over the course of about 45 days.

11. The stable wood preservative formulation of claim 1 , wherein said formulation further comprises one or more organic solvents.

12. The stable wood preservative formulation of claim 11 , wherein said organic solvent is selected from the group consisting of glycols, esters, alcohols, and amide solvents.

13. The stable wood preservative formulation of claim 12 , wherein said glycol solvent is selected from the group consisting of diethylene glycol, dipropylene glycol, ethylene glycol, glycerine, glycerol, hexylene glycol, neopentylglycol, polyethylene glycol, polypropylene glycol, tetraethylene glycol, triethylene glycol, and tripropylene glycol.

14. The stable wood preservative formulation of claim 12 , wherein said ester solvent is selected from the group consisting of amyl acetate, dibasic ester, ethyl acetate, 2-ethyl hexyl acetate, ethyl propionate, acetate esters, isobutyl acetate, isobutyl isobuterate, isopropyl acetate, n-butyl acetate, n-butyl propionate, n-pentyl propionate, and n-propyl acetate.

15. The stable wood preservative formulation of claim 12 , wherein said alcohol solvent is selected from the group consisting of amyl alcohol, benzyl alcohol, cyclohexanol, ethyl alcohol-denatured, 2-ethyl hexanol, isooctyl alcohol, isodecyl alcohol, tridecyl alcohol, furfuryl alcohol, isobutyl alcohol, methanol, methyl amyl alcohol, methyl isobutyl carbinol (MIBC), n-butyl alcohol, n-propyl alcohol, secondary butyl alcohol, tertiary butyl alcohol, and tetrahydrofurfuryl alcohol.

16. The stable wood preservative formulation of claim 12 , wherein said amide solvent is selected from the group consisting of N-methyl-2-pyrrolidone, N-methylformamide, dimethylacetamide, dimethylformamide, N-vinylacetamide, N-vinylpyrrolidone, 1-octyl-2-pyrrolidone, N,N-dimethyl 9-decenamide, dimethyl lauramide, N,N-dimethyl-dodecanamide, N,N-dimethylmyristamide, and N,N-dimethyldecanamide.

17. The stable wood preservative formulation of claim 11 , wherein the total weight ratio of the one or more organic solvents to the total azole is from about 1:1 to about 50:1.

18. The stable wood preservative formulation of claim 11 , wherein the total weight ratio of the one or more organic solvents to the total azole is from about 2:1 to about 10:1.

19. The stable wood preservative formulation of claim 11 , wherein the total weight ratio of the one or more organic solvents to the total azole is from about 2:1 to about 5:1.

20. The stable wood preservative formulation of claim 1 , wherein said formulation is diluted with water prior to contacting wood or a wood product.

21. The stable wood preservative formulation of claim 1 , wherein said isothiazole-based mold inhibitor is selected from the group consisting of methylisothiazolinone (MIT), chloromethylisothiazolinone (CMIT), octylisothiazolinone (OIT), dichlorooctylisothiazolinone (DCOIT), benzisothiazolinone (BIT), methylbenzisothiazolinone (MBIT), and butylbenzisothiazolinone (BBIT).

22. The stable wood preservative formulation of claim 1 , wherein said temperature is from about 5° C. to about 45° C., or about 10° C. to about 40° C., or about 15° C. to about 35° C., or about 20° C. to about 30° C.

23. A method of treating wood or a wood product comprising contacting the stable wood preservative formulation of claim 1 with wood or a wood product.

24. Wood or a wood product treated with the stable wood preservative formulation of claim 1 .