Micronized wood preservative formulations

Abstract

The present invention provides wood preservative compositions comprising micronized particles. In one embodiment, the composition comprises dispersions of micronized metal or metal compounds. In another embodiment, the wood preservative composition comprises an inorganic biocide comprising a metal or metal compound and organic biocide. When the composition comprises an inorganic biocide and an organic biocide, the inorganic biocide or the organic biocide or both are present as micronized particles. When compositions of the present invention are used for preservation of wood, there is minimal leaching of the metal and biocide from the wood.

Description

[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 10 / 821,326, filed on Apr. 9, 2004, which claims the benefit of priority to U.S. Provisional Application Ser. No. 60 / 461,547, filed Apr. 9, 2003, and U.S. Provisional Application Ser. No. 60 / 518,994, filed Nov. 11, 2003, the disclosures of which are each incorporated herein by reference. This application is also a continuation-in-part of U.S. patent application Ser. No. 10 / 970,446 filed on Oct. 21, 2004, which claims the benefit of priority to U.S. Provisional Application Ser. No. 60 / 565,585, filed Apr. 27, 2004, the disclosures of which are each incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention is related generally to the field of wood preservatives and more particularly to a wood preservative composition comprising micronized metal biocides and fungicides.BACKGROUND OF THE INVENTION[0003]Wood-preserving compositions are well known for preserving wood and other cellu...

AI Technical Summary

Benefits of technology

The present invention provides a micronized composition for preserving wood that includes metal or metal compounds and organic biocides. The micronized metal or metal compounds can be in the form of particles or soluble forms. The composition can be in the form of a solution or emulsion. When used on wood, the composition minimizes leaching of the metal or metal compounds and organic biocides from the wood. The wood-preserving compositions can be used in various wood products such as cellulosic materials, paper, particleboard, textiles, rope, and the like. The invention also provides a method for using the wood-preserving compositions. The micronized inorganic biocide used in the composition has a particle size of 0.001 to 25.0 microns. The inorganic biocide can be copper, copper compounds, or other metal compounds such as cobalt, cadmium, nickel, tin, silver, or zinc. The inorganic biocide can be micronized inorganic biocide or dispersed in a dispersant. The composition can be in concentrated form.

Problems solved by technology

The disadvantage of using ammonia as a copper solubilizing agent lies in the strong odor of ammonia.

Additionally, copper-ammonia preservatives can affect the appearance of the treated wood giving surface residues and undesirable color.

However, copper-amine based preservatives have higher copper loss due to leaching as compared to traditional copper-based preservatives such as chromated copper arsenate (CCA).

However, many organic biocides currently in use are not water soluble.

However, the solubilizing agents, surfactants, and wetting agents are costly and the use of these products may result in enhanced leaching of the biocides when the treated material comes into contact with moisture.

Because these compounds continue to cause leaching of the metal and / or biocide from the treated wood, field performance problems or environmental issues can result.

Despite many efforts to address these deficiencies in existing wood preservatives, there has been an unmet need to produce aqueous metal-based preservatives that are suitable for treating wood and other cellulose-based materials while minimizing the undesirable leaching of metal ions and / or biocide from treated materials when exposed to water.

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