Wood preservatives
View Patent ↗A method for preserving wood by contacting wood with a composition comprising an aqueous polymer dispersion, at least one surfactant, and a wood preservative.
1. A method for preserving wood; said method comprising contacting wood with a composition comprising:
(a) an aqueous styrene-acrylic polymer emulsion having an average particle size less than 1000 nm, in which the polymer has a T g no greater than 39° C.;
(b) at least one surfactant selected from among nonionic and anionic surfactants; and
(c) at least one wood preservative selected from among halogenated isothiazolone biocides, halogenated carbamate fungicides and azole fungicides.
2. The method of claim 1 in which said average particle size is less than 500 nm and said at least one wood preservative comprises a halogenated isothiazolone biocide.
3. The method of claim 2 in which the wood preservative is 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one.
4. The method of claim 3 in which said at least one surfactant comprises a nonionic surfactant containing at least 15 ethylene oxide monomer units.
5. The method of claim 4 in which the composition comprises 0.05% to 6% polymer solids, 0.01% to 1% of said at least one surfactant, and 500 ppm to 6000 ppm 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one.