US 20060O86284A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2006/0086284 A1 Zhang et al. (43) Pub. Date: Apr. 27, 2006 (54) NON-ALKALINE MICRONIZED WOOD Related U.S. Application Data PRESERVATIVE FORMULATIONS (60) Provisional application No. 60/618,733, filed on Oct. 14, 2004. (76) Inventors: Jun Zhang, Getzville, NY (US); Robert M. Leach, Grand Island, NY Publication Classification (US) (51) Int. Cl. C09D 5/14 (2006.01) Correspondence Address: BOSD 3/12 (2006.01) HODGSON RUSS LLP (52) U.S. Cl. ......................................... 106/15.05; 427/351 ONE M & T PLAZA SUTE 2000 (57) ABSTRACT BUFFALO, NY 14203-2391 (US) Provided is a non-alkaline composition for the preservation of wood and other cellulosic materials. The composition (21) Appl. No.: 11/250,312 comprises an aqueous dispersion of micronized inorganic compounds and/or organic biocides. Also provided is a (22) Filed: Oct. 14, 2005 method for making the composition. Patent Application Publication Apr. 27, 2006 Sheet 1 of 2 US 2006/0086284 A1 trachelics it pairs ravy cells eS C ana Figure 1 Patent Application Publication Apr. 27, 2006 Sheet 2 of 2 US 2006/008.6284 A1 Bordered Pit cell vall tous pit aspiration pit aperture margo (microfibrils) simple pits Figure 2 US 2006/008.6284 A1 Apr. 27, 2006 NON-ALKALINE MCRONIZED WOOD strates. However, the solubilizing agents, Surfactants, and PRESERVATIVE FORMULATIONS wetting agents are costly and the use of these products may 0001. This application claims priority to U.S. provisional result in enhanced leaching of the organic biocides when the application no. 60/618,733, filed on Oct. 14, 2004, the treated material comes into contact with moisture, giving disclosure of which is hereby incorporated by reference. rise to field performance problems or environmental issues. FIELD OF THE INVENTION 0007. Despite efforts to address these deficiencies in existing wood preservatives, there has been an unmet need 0002 The present invention pertains to wood preserva for aqueous preservatives that are suitable for treating wood tion, and more specifically to the use of micronized metals, and other cellulose-based materials while minimizing the metal compounds, and organic biocides as wood preserva undesirable leaching of metal ions and/or organic biocides tives. from treated materials when the materials are exposed to Water. BACKGROUND OF THE INVENTION 0003 Wood preserving compositions are well known for SUMMARY OF THE INVENTION preserving wood and other cellulose-based materials. Such as paper, particleboard, textiles, rope, etc., against organisms 0008 Provided are micronized compositions which are responsible for the destruction of wood, such as, for neutral or acid in pH. The present invention provides example, microbes, fungi and insects. Many conventional micronized compositions for preservation of wood wherein wood preserving compositions contain copper ammine com the pH of the compositions is neutral or acidic i.e., pH of less plexes. Copper ammine complexes have been used hereto than or equal to about 7.0 with a preferred range of pH 5.0 fore because of the ease with which ammonia solubilizes to pH 7.0. copper in aqueous solutions, forming such complexes. Cop per is readily available from a variety of copper bearing 0009. Accordingly, in one embodiment a wood preserva materials, including copper scrap, cuprous and cupric tive composition having a pH of 7.0 or less is provided oxides, copper carbonate, copper hydroxide, a variety of comprising one or more micronized metals, metal com cuprous and cupric salts, and copper bearing ores. The pounds or combinations thereof. ammonia used in the formation of copper ammine com plexes is readily available as an aqueous ammonia Solution, 0010. In another embodiment an aqueous wood preser and/or as a solution formed by the dissolution of ammonium vative composition having a pH of 7.0 or less is provided, salts, such as ammonium carbonate, and ammonium sulfate, comprising one or more micronized metals or metal com ethanolamines, etcetera. For example, U.S. Pat. No. 4,622, pounds and one or more water-soluble organic biocides. 248 describes the formation copper amine complexes by 0011. In another embodiment an aqueous wood preser dissolving copper (II) oxide CuO (cupric oxide) in ammo vative composition having a pH of 7.0 or less is provided, nia in the presence of ammonium bicarbonate. comprising one or more micronized metals or metal com 0004 Ammonia has disadvantages as a copper solubiliz pounds and one or more micronized organic biocides. ing agent due to, among other things, its strong odor and the ability of copper ammonia preservatives to affect the appear 0012. In another embodiment an aqueous wood preser ance of the treated wood, giving Surface residues an unde vative composition having a pH of 7.0 or less is provided, sirable color. comprising one or more micronized organic biocides. 0005. In recent years, many amine-containing com 0013 In another embodiment an aqueous wood preser pounds, such as the ethanolamines and aliphatic polyamines, vative composition having a pH of 7.0 or less is provided, have been used to replace ammonia in the formulation of comprising one or more micronized organic biocides, and water-soluble copper Solutions. These compounds have one or more water-soluble metal compounds. strong complexing ability with copper and they are essen tially odorless. U.S. Pat. No. 4,622,248 discloses a method 0014. Also provided is a method for preserving cellulosic of preparing copper amine complexes by dissolving a mix materials with the compositions of the present invention. ture of copper (II) carbonate CuCO and copper (II) The method comprises the step of impregnating a cellulosic hydroxide Cu(OH) in ethanolamine and water. The com material. Such as wood, with a micronized composition of plexing amine (i.e., the ligand) and copper (II) ion combine the present invention. When the compositions of the present Stoichiometrically. However, copper amine based preserva invention are used for preservation of wood, minimal leach tives have higher copper loss due to leaching compared to ing of the micronized components from the wood upon other traditional copper based preservatives such as more exposure to the environment is generally observed. traditional amine?ammonia-free preservatives such as chro mated copper arsenate (CCA). 0015. In another embodiment, a preferred wood preser 0006. In addition to metal biocides, existing wood pre Vative composition is copper or a copper compound com servatives can also contain organic biocides. However, many prising particles in the form of a micronized dispersion organic biocides currently in use are not water Soluble. comprising particles having sizes in the range of 0.001 Therefore, Solubilizing agents, Surfactants and wetting microns to 25.0 microns. The dispersion can be present in agents are often added to either solubilize or form emulsions the preservative composition with one or more water soluble of the organic biocide in order to formulate a product that is and/or water insoluble organic biocides. The composition suitable for the treatment of wood or other cellulose sub has a pH of 7.0 or less. US 2006/008.6284 A1 Apr. 27, 2006 BRIEF DESCRIPTION OF THE FIGURES 0022 Metals or metal compounds which can be used in the preservative compositions of the present invention in 0016 FIG. 1 depicts the anatomy of coniferous wood. their elemental form or as compounds include transition 0017 FIG. 2 depicts the border pit structure for conif elements (including the lanthanide and actinide series ele erous wood. ments) Such as copper, strontium, barium, arsenic, antimony, bismuth, lead, gallium, indium, thallium, tin, Zinc, cadmium, DETAILED DESCRIPTION OF THE silver, nickel, etc. INVENTION 0023. A preferred metal is copper. Accordingly, in one 0018. The term “micronized as used herein means a embodiment, copper or copper compounds are used. The particle size in the range of 0.001 to 25 microns. Further copper or copper compounds such as cuprous oxide (a more, it should be understood that “micronized' does not Source of copper (I) ions), cupric oxide (a source of copper refer only to particles which have been produced by the (II) ions), copper hydroxide, copper carbonate, basic copper finely dividing, such as by mechanical grinding, of materials carbonate, copper oxychloride, copper 8-hydroxyquinolate, which are in bulk or other form, but to particles in the copper dimethyldithiocarbamate, copper omadine, copper foregoing size range, whether they are ground from larger borate, copper residues (copper metal byproducts) or other stock, formed in situ, or formed by other methods. The term “preservative' as used herein refers to a composition which, Suitable copper source can be used as micronized particles upon application, increases the resistance of a cellulosic having a particle size between 0.001 microns to 25 microns. material to insect, fungal or microbial attack. The term 0024. The present invention includes compositions which “particle size” refers to the largest axis of the particle, and comprise one or more organic biocides which may be in the case of a generally spherical particle, the largest axis water-soluble or micronized, depending upon the embodi is the diameter. It should be understood that a “dispersion' ment employed. In one embodiment, a water-soluble inor of micronized particles as used herein encompasses situa ganic compound is used with a micronized organic biocide. tions in which particles are present with sizes outside the A range of water-soluble inorganic components can be used. micronized range. However, it is preferred that greater than Examples of Such are water-soluble copper compounds. In 80 weight percent of the particles have diameters in the one embodiment, non-copper-containing water-soluble inor micronized range, and even more preferred that greater than ganic compounds can be used instead of or in addition to 60 wt % of the micronized particles have a size of between copper-containing biocides.